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AUTOMOBILES (26 journals)

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ATZ - Automobiltechnische Zeitschrift     Hybrid Journal   (Followers: 7)
ATZ worldwide     Hybrid Journal   (Followers: 2)
ATZautotechnology     Hybrid Journal   (Followers: 1)
ATZelektronik     Hybrid Journal   (Followers: 2)
ATZelektronik worldwide     Hybrid Journal   (Followers: 1)
ATZextra     Hybrid Journal   (Followers: 1)
ATZextra worldwide     Hybrid Journal  
ATZproduktion     Hybrid Journal   (Followers: 1)
ATZproduktion worldwide     Hybrid Journal  
Auto Tech Review     Hybrid Journal  
Automotive Agenda     Hybrid Journal   (Followers: 1)
Automotive and Engine Technology     Hybrid Journal  
Automotive Experiences     Open Access  
Automotive Innovation     Hybrid Journal  
Bulletin of NTU - Dynamics and strength of machines     Open Access  
IEEE Transactions on Intelligent Vehicles     Hybrid Journal   (Followers: 2)
International Journal of Automotive Composites     Hybrid Journal   (Followers: 5)
International Journal of Automotive Science And Technology     Open Access   (Followers: 1)
International Journal of Automotive Technology     Hybrid Journal   (Followers: 4)
International Journal of Automotive Technology and Management     Hybrid Journal   (Followers: 5)
International Journal of Vehicle Performance     Hybrid Journal  
MECCA Journal of Middle European Construction and Design of Cars     Open Access  
MTZ - Motortechnische Zeitschrift     Hybrid Journal   (Followers: 1)
MTZ industrial     Hybrid Journal   (Followers: 2)
MTZ worldwide     Hybrid Journal  
Proceedings of the Institution of Mechanical Engineers Part D: Journal of Automobile Engineering     Hybrid Journal   (Followers: 14)
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Proceedings of the Institution of Mechanical Engineers Part D: Journal of Automobile Engineering
Journal Prestige (SJR): 0.729
Citation Impact (citeScore): 2
Number of Followers: 14  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0954-4070 - ISSN (Online) 2041-2991
Published by Sage Publications Homepage  [1176 journals]
  • Applications of adhesive bonding

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      Authors: Lucas FM da Silva, Robert D Adams, Chiaki Sato, Klaus Dilger
      Pages: 2975 - 2975
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Volume 237, Issue 13, Page 2975-2975, November 2023.

      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-10-31T11:46:22Z
      DOI: 10.1177/09544070231185666
      Issue No: Vol. 237, No. 13 (2023)
       
  • The model-based development of a dynamic test bench for testing damper
           assemblies with a focus on amplitudes with small excitations

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      Authors: David Benz
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Damper assemblies are often tested on test benches with relatively large displacement amplitudes at high velocities. Stochastic excitations, as road irregularities can usually be described, have a high proportion of amplitudes with small excitations; the so-called small signals. Testing with small signals poses special challenges for test benches. A methodology is presented that uses a quarter vehicle model and synthetically generated road irregularities to estimate the displacement, velocity, and acceleration amplitudes occurring at a damper assembly model. In order to describe a more realistic vehicle behavior, the synthetically generated road irregularities undergo a reduction of the amplitudes in corresponding frequency ranges by means of linear filters. The evaluation of the amplitudes occurring at the damper assembly is used to make a selection of the actuator for the test bench. A nonlinear dynamic model of the test bench, a so-called “Digital Twin,” is then created, which focuses on both, the model of the permanent magnet synchronous machine and the mechanical model of the linear actuator. Furthermore, a controller optimization procedure is used to virtually optimize the test bench’s controller parameters. Using the optimized parameters after the build process of the test bench, damper assembly tests with small signals of high quality are possible. With the help of virtual development methods such as synthetically created filtered road irregularities and with a Digital Twin of the test bench, a fast test bench development is possible. Realistic results can be achieved.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-11-25T11:14:32Z
      DOI: 10.1177/09544070231207523
       
  • Evaluation of the transient performance of a two-stage hybrid boosting
           system for spark ignition engines

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      Authors: Vittorio Usai, Silvia Marelli
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      This paper investigates a two-stage hybrid boosting system aimed at minimizing the delay in torque delivery that commonly characterizes turbocharged engines. Turbo-lag, particularly at low loads, reduces drivability, making the vehicle less competitive in the market. However, turbocharging is currently a simple and effective way of achieving high levels of specific power and efficiency, making its application mandatory. Hybridizing the turbocharging system by integrating a conventional turbocharger with an electrically assisted compressor can offer a solution to mitigate turbo-lag. The high dynamic response of the e-compressor significantly reduces time-to-boost, thus improving the engine’s response to load changes. This work presents the hybrid configuration with reference to a specific experimental campaign conducted on the University of Genoa’s test bench for components of propulsion system. The main results are presented, focusing on the boost pressure dynamic response during transient operations, highlighting the system’s behavior in various conditions and the benefits obtained by adopting an e-compressor in terms of time-to-boost. Furthermore, the experimental tests allow for the evaluation of the e-compressor electric power consumption under different operating conditions. The experimental results are then used as a reference to build a 1D model in GT-Power, reducing costs and time related to the experimental campaign while validating the data measured on the test bench.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-11-14T12:34:57Z
      DOI: 10.1177/09544070231209082
       
  • Wind tunnel testing of a Formula Student vehicle for checking CFD
           simulation trends

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      Authors: Jaime Pacheco, André C Marta, Luis Eça
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The aerodynamic performance analysis of Formula Student racecars has been mostly done by teams with CFD tools, for time and cost savings, that often lack proper validation. To address this, the FST Lisboa team performed a detailed wind tunnel (WT) test campaign, using a one-third scale model, under different configurations, including variable ride heights, bullhorn appendix, and rear wing flap settings, also replicated in CFD. The simulations used RANS with the SST k-omega turbulence model, with a 13.7 million polyhedral mesh for the test chamber region domain. Both experimental and numerical errors were estimated from the instrumentation and mesh convergence analysis, respectively. Comparisons were made between WT and CFD both in terms of local flow, using tufts for flow visualization, and global flow, using lift, drag, and pitching moment coefficients. Overall, the numerical streamlines agreed very well with the orientations of the tufts in experiments, but some discrepancies were found in regions of cross-flow and high-frequency unsteadiness, mainly caused by limitations of the visualization technique. The gamma transition model in CFD was abandoned as it could not replicate the WT observations. In terms of aerodynamic coefficients, a strong correlation was found between WT and CFD. The parametric studies revealed that the simulations captured the experimental sensitivity to each car setting parameter studied but the uncertainties did not enable a full quantitative evaluation of the aerodynamic performance. The drag reduction system significantly impacted the aerodynamic balance of the racecar, while the current bullhorn design proved to be ineffective. The ride height increase led to higher downforce, mostly due to the higher pitch angle of the vehicle, with negligible variation of the aerodynamic balance. This work validated the team CFD studies, building confidence in that trends estimated in numerical parametric studies are likely to be translated to the real prototype performance.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-11-07T12:25:44Z
      DOI: 10.1177/09544070231203076
       
  • Vision-based environmental perception for autonomous driving

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      Authors: Fei Liu, Zihao Lu, Xianke Lin
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Visual perception plays an important role in autonomous driving. One of the primary tasks is object detection and identification. Since the vision sensor is rich in color and texture information, it can quickly and accurately identify various road information. The commonly used technique is based on extracting and calculating various features of the image. The recent development of deep learning-based method has better reliability and processing speed and has a greater advantage in recognizing complex elements. For depth estimation, vision sensor is also used for ranging due to their small size and low cost. Monocular camera uses image data from a single viewpoint as input to estimate object depth. In contrast, stereo vision is based on parallax and matching feature points of different views, and the application of Deep learning also further improves the accuracy. In addition, Simultaneous Location and Mapping (SLAM) can establish a model of the road environment, thus helping the vehicle perceive the surrounding environment and complete the tasks. In this paper, we introduce and compare various methods of object detection and identification, then explain the development of depth estimation and compare various methods based on monocular, stereo, and RGB-D sensors, next review and compare various methods of SLAM, and finally summarize the current problems and present the future development trends of vision technologies.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-11-04T10:26:23Z
      DOI: 10.1177/09544070231203059
       
  • Classification of convertible car roofs and basics of their operation

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      Authors: Hubert Skowronek
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      This paper deals with cabrio type cars. The most interesting currently used solutions and groundbreaking designs from the last decades are presented. This paper contains collected knowledge on kinds of convertible roofs found in mass produced cabriolets. With the development of the automotive technology such constructions have evolved from simple mechanisms operated using the force of human muscles to highly complex mechatronic systems. The author introduces his own classification of car roofs with regard to their mechanical structure and the medium used to change the body status from closed to open and vice versa. In the second part of this publication the basics of the operation of car roof mechanisms are provided.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-11-02T12:09:13Z
      DOI: 10.1177/09544070231204393
       
  • Quasi-static shock absorber friction at low velocity reciprocating sliding
           conditions

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      Authors: Clemens Deubel, Bastian Schubert, Günther Prokop
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The characteristics of vehicle shock absorbers have a major significance regarding vehicle dynamics, thus affecting vehicle ride comfort, handling and safety. Although much research focuses particularly on the hydraulic damping properties of this vital suspension component, friction properties are not considered in great detail. However, for driving scenarios of low excitation and velocity of the shock absorber due to moderate roughness of the road, the friction force generated by the shock absorbers and the remaining components is particularly important regarding the transfer of vibration from the road to the passenger. Hence, this study investigates the sensitivity of shock absorber friction to various parameters in the quasi-static domain. The effects of side force, temperature, excitation amplitude and waveform are determined for multiple shock absorbers. The results show no significant influence of the amplitude and waveform used in the conducted tests. Contrarily, the friction force strongly depends on the side force, which represents the variable load perpendicular to the shock absorber’s main axis arising during various driving events for MacPherson suspensions. An increased temperature reduces the side force effect.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-10-25T12:55:01Z
      DOI: 10.1177/09544070231201688
       
  • Impact of engine control variables on low load combustion efficiency and
           exhaust emissions of a methane-diesel dual fuel engine

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      Authors: Nikhil D Khedkar, Asish K Sarangi, Sheshadri Sreedhara
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      A conventional diesel engine when operated in the reactivity-controlled compression ignition (RCCI) combustion strategy faces challenges of high total hydrocarbon (THC) and carbon monoxide (CO) emissions leading to poor combustion efficiency at low engine loads. The oxides of nitrogen (NOx) versus smoke trade-off, encountered in conventional diesel combustion, is replaced by the NOx-THC trade-off in the RCCI operation. This work focuses on addressing the NOx-THC trade-off issue by systematically investigating the effects of engine control variables, such as, fuel injection timing, exhaust gas recirculation (EGR) and intake throttling, on a light duty compression ignition engine running in a methane-diesel dual fuel mode. The engine is operated at a load of 3 bar gross indicated mean effective pressure and at a speed of 1500 rev/min. Based on relationships identified between engine control variables, combustion parameters, emissions and engine performance, a bottom-up approach is used to combine the control variables synergistically to improve the NOx-THC trade-off. A combination of advanced start of injection timing of diesel (−35 degree crank angle (°CA) after top dead centre), 50% premix ratio and 55% EGR levels along with the end of port fuel injection of methane in the middle of the intake stroke (−270°CA), has resulted in a ∼34 percentage points (from 56% to 90%) improvement in combustion efficiency and a ∼9.5 percentage points improvement in thermal efficiency compared to the baseline low load dual fuel operation while maintaining good combustion stability. THC emission is reduced from 105 to ∼25 g/kWh whilst maintaining low levels of NOx (
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-10-25T12:50:42Z
      DOI: 10.1177/09544070231197613
       
  • Investigation and optimization of energy absorption of squared-section
           thin-walled structure under lateral dynamic loading

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      Authors: M Kazemi, M Aryaie, D Nouri
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In many engineering structures, especially transportation systems, energy-absorbing structures are used to prevent or reduce collision damage. Thin wall structures are an important category of these systems. The present study investigates the level of energy absorption and crushing behavior of thin-walled aluminum structures with multi-cell square sections under lateral impact loading. The material used to produce the samples is AL-6061. The samples were subjected to lateral impact loading by combining different wall thicknesses to determine the optimal cross-section geometry. For this purpose, numerical simulation was conducted using Abaqus software. Firstly, the simulation method was validated, and after validation, different combinations of multi-cell square sections with varying wall thicknesses were designed using the Design of Experiment (DOE) method. Additionally, due to the assumption of thin walls in the structures, the wall thicknesses of the samples were considered in the range of 1 to 3 mm. The mass and initial velocity of the impactor are 35.7 kg and 6.26 m/s, respectively. The results showed that the wall thickness of the structures and their different combinations can have a significant effect on their energy absorption parameters. These effects are generally nonlinear, with severe effects observed in some cases. Finally, through the analysis of the energy absorption process of the structures and the use of the response surface method (RSM), an optimal sample was designed and simulated. The results indicate an increase of approximately 246% in the specific energy absorption of the optimal sample compared to the sample with the same wall thickness.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-21T11:16:21Z
      DOI: 10.1177/09544070231182132
       
  • Numerical investigation on nucleate bubble departure by
           electrowetting-on-dielectric in battery cooling plates

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      Authors: Haolun Xu, Shenghua Yu, Jianjian Liu, Zhiming Hu, Mingzhe Song
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      A thermal management system is necessary to control battery operating temperature in electric vehicles (EV). Typically, the most common way to dissipate heat from the battery pack is to use the cooling plate. The cooling medium in the cooling plate removes the excess heat from the battery pack through boiling heat transfer. This paper proposes an electrowetting-on-dielectric (EWOD) method to enhance the bubble departure in nucleate boiling heat transfer in a cooling plate. In order to investigate the bubble splitting due to the EWOD effect, theoretical models are developed to solve for the electrophoretic force, dielectrophoretic force, and electrostrictive force. The theoretical model coupled a phase field method with an electric conservation model, where the body force acts as an external force due to the electric field. Our preliminary simulation results demonstrated that the EWOD effect can change the apparent contact angle when applied to a certain electric field. The free charge density displays at the dielectric layer interface with water and at the bubble’s interface near the triple contact point. Then two types of simulation case were investigated to apply the voltage in the battery cooling plates. In the first case, a pair of parallel discs are used as the electrodes at the bottom and top of the region. In the second case, the voltage is applied at the top of the nucleate bubble in a rod electrode. The various behavior of bubble dynamics were compared and discussed to indicate the optimized case for enhancing the nucleate bubble departure in the EV battery cooling plates.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-20T09:22:52Z
      DOI: 10.1177/09544070231199282
       
  • Theoretical and experimental analysis of electric vehicle motor dynamics
           under the coupling of harmonic current and temperature excitation

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      Authors: Dong Guo, Xiang Luo, Mingmao Hu, Ming Li, Jie Ren, Yutong He, Yufa Zhou
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The NVH performance of electric vehicles is crucial for human comfort, and the electric drive system is key to NVH performance. Permanent magnet synchronous motors experience high-temperature increases under high-speed operating conditions, resulting in motor structure deformation at high-temperatures. The radial deformation of the stator alters the airgap dimensions of the motor’s electromagnetic field. The airgap of the motor’s magnetic field has high-sensitivity to these changes aggravating the vibration and noise problems. Harmonic currents in high-speed vehicle motors add to these problems. Therefore, motor dynamics must be studied under the joint influences of airgap distortion and harmonic currents. We proposed a method of modeling permanent magnet synchronous motors under the joint effect of harmonic currents and temperature fields. And established an accurate multi-field coupled vibration response prediction model for permanent magnet synchronous motors. The accuracy of the vibration prediction model was subjected to a bench test. The vibration characteristics of the motor were studied using order and spectrum analyses. We found that the airgap magnetic-field distortion, due to the motor and stator thermal deformation, significantly affected the motor vibration characteristics. The main motor vibration noise was caused by the 24th and 48th order electromagnetic force waves. This provides a reference for establishing an accurate vibration prediction model for permanent magnet synchronous motors.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-20T09:14:52Z
      DOI: 10.1177/09544070231198281
       
  • The tyre blow-out vehicle lateral pulling control using an active
           suspension system with comfort-lateral trajectory based control scheme.

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      Authors: Sathishkumar P, Thiyagarajan Jayaraman, Muthuramalingam Thangaraj
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      When a tyre blows out, the vehicle’s trajectory deviates from the intended path, resulting in an accident and death. Because of its larger contact patch, applying more steering force to the flat tyre will cause the tyre to separate from the wheel. Also, improper braking effort causes rollover related issues due to the sudden vehicle’s centre of gravity (C.G.) displacement and weight transfer towards the blow-out tyre. Therefore, this research attempts to return the C.G. to its initial position through the suspension control. The force supplied between the sprung and unsprung masses of the flat tyre through suspension actuator is estimated and controlled by the model predictive control (MPC) scheme with respect to its input signals. For the non-linear simulation, the four-wheel passenger car vehicle dynamic model and the combined empirical model for the tyre inflation pressure effect are used. And the equivalent plant model is identified through a simple system identification method for the MPC design. The passive and active based suspension of standalone, roll-resistant interconnected and pitch-resistant interconnected systems, including the proposed comfort-lateral trajectory controlled standalone active suspension, were examined. To assess the effectiveness of each suspension and its control strategy in a tyre blow-out scenario, a vehicle was analysed with various longitudinal velocities along with and without steer input.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-20T09:08:57Z
      DOI: 10.1177/09544070231197584
       
  • Planning and tracking control of full drive-by-wire electric vehicles in
           unstructured scenario

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      Authors: Guoying Chen, Min Hua, Wei Liu, Jinhai Wang, Shunhui Song, Changsheng Liu, Liunan Yang, Shihui Liao, Xin Xia
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Full drive-by-wire electric vehicles (FDWEV) equipped with X-by-wire technology can enable independent driving, braking, and steering of each wheel, making them an ideal platform for developing autonomous driving technology. However, designing a robust control algorithm that comprehensively integrates vehicle path planning in a complex and unstructured scenario is a challenging task for FDWEV. To address this issue, this paper (1) proposes the artificial potential field (APF) method for path planning in the prescribed park with different static obstacles to generate the reference path information, where speed planning is incorporated considering kinematics and dynamic constraints; (2) designs curvature calculation (CC-based) and model predictive control (MPC-based) tracking methods with the lateral dynamics model to track the desired path under different driving conditions, in which a forward-looking behavior model of the driver with variable preview distance is designed based on the fuzzy control theory; (3) conducts CarSim-AMESim-Simulink co-simulation with the existence of obstacles. The simulation results show that the proposed two control approaches are practical for classical driving scenarios. Especially the MPC-based path-tracking controller enhances dynamic tracking performance and ensures good maneuverability under high-dynamic driving conditions.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-20T09:02:28Z
      DOI: 10.1177/09544070231195233
       
  • Collaborative adaptive cruise control and energy management strategy for
           extended-range electric logistics van platoon

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      Authors: Gang Wang, Hongliang Wang, Dawei Pi, Xiaowang Sun, Xianhui Wang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      This paper improves the economy of the extended-range electric logistics van (ERELV) platoon from two aspects of cooperative adaptive cruise control (CACC) and energy management strategy (EMS). Based on the vehicle-to-everything (V2X) communication, to improve the economy of heterogeneous vehicle platoon CACC system, a distributed model predictive controller (DMPC) with stability, comfort, and the economy as optimization goals are designed. The sufficient conditions for the asymptotic stability of the vehicle platoon closed-loop system are obtained by Lyapunov stability analysis. The multi-agent deep reinforcement learning (MADRL) algorithm is used to solve the EMS of the ERELV platoon. Under the framework of centralized training distributed execution (CTDE), the experience of all agents can be obtained during training, and the actions can be output only according to their local observation states during execution. The simulation results show that the designed ecological cooperative adaptive cruise control (Eco-CACC) effectively balances the stability and economy of a heterogeneous vehicle platoon. Taking dynamic programming (DP) as the benchmark, compared with the single-agent algorithm, EMS based on a multi-agent deep deterministic strategy gradient (MADDPG) algorithm can achieve a near-optimal solution while significantly improving the learning efficiency.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-20T08:52:16Z
      DOI: 10.1177/09544070231193187
       
  • Investigating the thermal and chemical kinetic effects of the internal
           residual on the cyclic dynamics at the dilute limits of a spark-ignition
           engine

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      Authors: Rachel Stiffler, James Drallmeier
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The cyclic variability in the misfire and partial burn regimes of a dilute spark-ignition engine are primarily due to the feed-forward mechanism present in the residual gases. This study experimentally investigates the influence of the specific heat capacity/thermal effect and chemical kinetic effect of the internal residual on the heat release dynamics in the misfire and partial burn regimes of a dilute spark-ignition engine. Each effect is investigated by displacing excess air with bottled N2 and CO. Both short-term and long-term heat release dynamics are analyzed using association rules. Results show both an increased amount of dilution and higher specific heat capacity can result in similar dynamics. It was also found the misfire regime appears to be more sensitive to the chemical kinetic effect than the partial burn regime. Comparison of spark-to-CA05 and spark-to-CA50 between dilution methods was also conducted, where it was found the chemical kinetic effect did tend to reduce both spark-to-CA05 and spark-to-CA50. Overall, results from this study suggest different control strategies may be necessary to effectively mitigate the combustion instabilities when operating in each regime.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-19T09:12:31Z
      DOI: 10.1177/09544070231187466
       
  • An algorithm for solving the equilibrium points of high-dimensional
           nonlinear vehicle dynamic system based on a combination of genetic
           algorithm, sequential quadratic programming method, and continuation
           method

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      Authors: Xianbin Wang, Reza Langari, Yulong Pei, Zhipeng Li, Weifeng Li
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The paper proposes an algorithm that combines Genetic Algorithm, Sequential Quadratic Programming, and Continuation Method to solve the equilibrium points of a multi-degree-of-freedom vehicle nonlinear system. The algorithm’s effectiveness is demonstrated by applying it to search for equilibrium points of a 5-degree-of-freedom (5DOF) nonlinear vehicle model, which considers both longitudinal and lateral motion. The dynamic equilibrium points of front-wheel-drive, rear-wheel-drive, and all-wheel-drive vehicles with different front-wheel steering angle inputs are calculated. Taking the front-wheel-drive system as an example, the system equilibrium points are further analyzed using phase space analysis and eigenvalue analysis for verification. In addition, the impact of the driving effect on the equilibrium points bifurcation is investigated. The results show that compared with the Genetic Algorithm alone and the combination method of Genetic Algorithm and Sequential Quadratic Programming, the proposed algorithm can effectively and accurately solve the equilibrium points of the 5DOF vehicle model. The study also reveals that the driving effect significantly influences the vehicle equilibrium point bifurcation.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-19T09:09:10Z
      DOI: 10.1177/09544070231197874
       
  • Slip slope change detection based on active drive force excitation

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      Authors: Andreas Fichtinger, Johannes Edelmann, Manfred Plöchl, Manuel Höll, Michael Unterreiner
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Identification of the available friction potential is crucial for road safety but difficult, in particular at normal driving. This paper aims to contribute by presenting an effect-based method for slip slope change detection related to friction potential changes at all wheel-drive vehicles applying active drive force excitation. The proposed estimation approach relies above all on the wheel speeds and the axle/wheel drive forces of the front and rear axle. Different types of periodic active drive force excitation that are superimposed to the drive force requested by the driver while maintaining the desired level of speed or acceleration are investigated w.r.t. the availability of the estimates and overall effectiveness of the estimator. Vehicle tests are performed to evaluate theoretical results and the (co-)driver’s perception of the active drive force excitation. Results from both the simulation study and vehicle tests show that the proposed method allows to reliably estimate slip slope changes at all-wheel drive vehicles in driving conditions with low levels of drive force excitation.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-19T09:06:11Z
      DOI: 10.1177/09544070231197378
       
  • Prediction of mid-high frequency noise in new energy electric vehicles

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      Authors: Dongxu Yang, Fei Wang, Hai Liu, Teng Ma, Hao Zhang, Weixiao Li
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Mid-high frequency noise in new energy electric vehicles is a critical factor affecting the comfort of car occupants. Such noise is generated near the electric motor and four tires, transmitted to the cabin through airborne, and finally perceived by the car occupants. Transfer Path Analysis is widely used for predicting cabin noise, but obvious time-consuming problems exist here. In this study, a time-efficient method called Inverse Transfer Path Analysis was used to calculate the mid-high frequency noise Airborne Transfer Function of a new energy electric vehicle. Then, the mid-high frequency noise at the driver’s ear position was predicted through an operational test. The results reveal that this method can accurately and efficiently predict the noise in the cabin. Furthermore, an artificial head was used to calculate the Head-Related Transfer Function from the external ear to the eardrum. This function was used to predict the mid-high frequency noise at the driver’s eardrum position, and the role of the human ear in the propagation of mid-high frequency noise has been analyzed.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-19T09:03:10Z
      DOI: 10.1177/09544070231196271
       
  • Eco-driving strategy for connected vehicles at signalized intersections
           considering human driver error

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      Authors: Jian Chen, Lijun Qian, Liang Xuan, Chen Chen
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In recent years, eco-driving strategies based on connected vehicle (CV) technologies have been studied to assist human drivers to reduce fuel consumption and pollutant emissions. In this paper, a real-time eco-driving strategy for CVs that considers human driver error is proposed to improve both traffic and fuel efficiency at signalized intersections where CVs and human-driven vehicles (HDVs) coexist. Firstly, a human driver error estimation model is established using real-world driving data. Then, based on the signal phase and timing information, vehicle state information, and the estimated human driver errors, a constrained nonlinear optimal control problem (OCP) is proposed to calculate the optimal advisory speed of each CV. The trajectory of HDV is estimated by utilizing the Gipps’ car-following model. Fast stochastic model predictive control (SMPC) is employed to solve the proposed OCP effectively. At last, simulation studies and real-vehicle experiments are conducted in various scenarios to verify the performance of the proposed strategy. Simulation and experiment results indicate that compared with the baseline strategies, the proposed eco-driving strategy can significantly reduce travel time and fuel consumption while ensuring the real-time performance.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-19T09:00:12Z
      DOI: 10.1177/09544070231192139
       
  • Electro-hydraulic composite stability control for regenerative braking
           failure of in-wheel motors drive electric vehicle

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      Authors: Jiantao Wang, Mingze Gao, Lipeng Zhang, Lirun Yin, Shuaishuai Liu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The in-wheel motor simplifies the structure of drive system and improves dynamic performance of vehicle. However, the regenerative braking failure of unilateral motor could greatly reduce braking strength and cause the instability of vehicle. The existing control methods are difficult to guarantee the braking performance and driving stability at the same time. To resolve this fail-safe problem, an electro-hydraulic composite stability control method is proposed and verified. Firstly, the vehicle model, the in-wheel motor model, and the hydraulic braking system model are built. Secondly, the electro-hydraulic composite stability control method is proposed and a stability controller based on model predictive control algorithm is designed to solve the problems of model uncertainty and external interference in the control process. Thirdly, the control effect of proposed method is compared with torque truncation control, hydraulic compensation control, and yaw stability control. Finally, the electro-hydraulic composite stability control method proposed in this paper is verified and tested on the real vehicle. The results show that the combination of the torque truncation control, the hydraulic compensation control, and yaw stability control could improve the driving stability of vehicle and meet the demand of braking intensity.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-15T04:34:43Z
      DOI: 10.1177/09544070231196208
       
  • Dynamic analysis of an electro-hydraulic interconnected actuator energy
           regeneration suspension

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      Authors: Pengtao Liu, Farong Kou, Yixiao Chen, Jianan Xu, Xinru Guo
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      A hydraulic interconnected suspension with energy recovery (EHA-HIS) is proposed to enhance riding comfort and road-holding ability while converting vibration energy into usable electrical energy. This paper mainly focuses on the dynamic analysis of a vehicle suspension model integrated with the EHA-HIS. The mathematical model of EHA-HIS is established based on the system structure analysis. The characteristics of the EHA-HIS are given based on a parameter analysis including the input and structural parameters under a sinusoidal excitation. Thereafter, vehicles equipped with the EHA-HIS and traditional suspensions are compared in terms of dynamic performance, and the simulation is implemented to study the energy harvesting performance of a vehicle with the EHA-HIS. The simulation results suggest that the damping force and harvested power are proportional to the frequency and amplitude of the sinusoidal input. The simulation also shows that the piston diameter has the greatest influence on the characteristics of the EHA-HIS. The analysis indicates that EHA-HIS can recover vibration energy while improving vehicle dynamic performance, and the harvestable power increases with the road grade and vehicle speed.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-13T12:21:31Z
      DOI: 10.1177/09544070231180001
       
  • Control of a nonlinear active suspension system based on deep
           reinforcement learning and expert demonstrations

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      Authors: Zhao Tan, Guilin Wen, Zebang Pan, Shan Yin, Xiaojian Wu, Gulbahar Tohti
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      A well-controlled active suspension system has the potential to provide better ride comfort. Benefiting from its powerful feature extraction and nonlinear generalization capabilities, the deep reinforcement learning (DRL), such as deep deterministic policy gradient (DDPG), has shown great potential to make decisions adaptively and intelligently in the control of active suspension system. However, the DDPG is troubled by the problem of low training efficiency due to the high proportion of illegal strategies. This paper proposed a novel DDPG controller for a nonlinear uncertain active suspension system by combining DRL with expert demonstrations. Specifically, the improved training method integrated with both a pre-training mechanism based on PID expert samples and an adaptive experience replay mechanism, is put forward for the DDPG to achieve both the goals of imitating the expert and improving the training efficiency. Moreover, considering the ride comfort and the state constraints as targets, a mixed reward function is designed to guide RL agents for learning effective actions. It is shown that the proposed training methods effectively accelerate the convergence of the DDPG. Furthermore, the comparison experiments demonstrate that the proposed controller provides great vibration attenuation, and has better adaptiveness to various working conditions and parametric uncertainty.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-13T11:27:23Z
      DOI: 10.1177/09544070231191842
       
  • Fatigue life prediction and structural optimization design of the bionic
           petal non-pneumatic tire with spokes

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      Authors: Jian Wang, Haohan Zeng, Qiang Gao, Guodong Yin, Junwei Li, Rongxian Qiu, Fujun Xiao
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Fatigue durability of the non-pneumatic tire (NPT) has a decisive influence on vehicle safety and transport economy. This paper aims at the research on the fatigue life prediction method suitable for the flexible spokes of the NPT, and explores the influence of structural parameters on fatigue performance. By simultaneously taking consideration of fatigue performance, bearing capacity, and weight of the NPT, the optimal model parameters are obtained by the proposed structural optimization method. Firstly, based on the Thomas crack model, the fatigue life of the bionic petal non-pneumatic (BP-NPT) is predicted. Then, the influential mechanism of key structural parameters including the curvature, array period, and spoke thickness on tire fatigue durability is investigated by numerical simulation methods. Finally, an optimization method based on the Kriging model and modified NSGA-II is proposed to optimize the structure characteristics of the BP-NPT for better fatigue life and bearing capacity while ensuring lightweight. The results show that the predicted fatigue failure mileage of the BP-NPT is 2.54 × 104 km. By properly increasing the curvature and thickness of the spoke, the maximum strain energy density of the BP-NPT will be reduced, thus improving its fatigue durability. The performance of the optimized structure is significantly improved by the proposed optimization method. The total mass is reduced by 7.44%. The fatigue life and bearing capacity are improved by 9.75% and 4.16%, respectively. It is indicated that a more durable and safer tire configuration is provided for tire safety applications.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-11T08:08:58Z
      DOI: 10.1177/09544070231197585
       
  • Unsteady gasdynamic modeling of double-entry turbine integrated with
           engine exhaust manifolds

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      Authors: Yingxian Xue, Mingyang Yang, Xingchen Wang, Chao Ma, Ying Liu, Wenlin Li
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Pulsating turbocharging system with a dual-entry turbine is always applied for the utilization of pulsating energy and improvement of low-speed torque for the internal combustion engine. With the enhancement of pulsating energy via the pulsating turbocharging system and dual-entry turbine, the interaction between exhaust manifolds and dual-entry turbine cannot be disregarded by either side when confronted by pulsating inflows. This paper proposes a gasdynamic model of double-entry turbine coupling with exhaust manifolds to examine the interaction effect between turbine and exhaust manifolds. This gasdynamic model can predict the propagation of pressure and mass flow rate from exhaust manifolds to the double-entry turbine as well as transient turbine performance. Predictions of this gasdynamic model are validated against detailed 3-D simulation and show good consistency with 3-D results. The performance and energy distribution of the double-entry turbine coupled to exhaust manifolds under various pulsating conditions are thoroughly discussed via this reduced-order model. Results show that with increasing frequency or amplitude of pulsating inflows imposed on inlets of the exhaust manifolds, the performance of the entire system deviates from the quasi-steady hypothesis, particularly the swallowing capacity. This phenomenon indicates that the matched operating point between the turbine and engine deviates from the quasi-steady conditions. In addition, exhaust manifolds geometries have a notable impact on turbine performance and energy distributions in exhaust systems. It is found that with an increase in the volume or length of the exhaust manifolds, the pulse at the turbine inlet is amplified, and available energy at the turbine inlet is increased, even though the inlet conditions of exhaust manifolds remain unchanged. This study may provide a guiding effect for the optimization of the turbo-engine matching process and the development of high-performance turbocharged engines.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-08T11:05:36Z
      DOI: 10.1177/09544070231191844
       
  • Enhancing vehicle localization by matching HD map with road marking
           detection

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      Authors: Zhe Zhou, Zhaozheng Hu, Na Li, Guoliang Lai
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Accurate and robust vehicle localization, a fundamental task for autonomous driving, is still a challenging problem especially in GPS-denied scenarios. Recently, high definition (HD) map suggests a promising solution. However, the matching between online sensed data and HD map is difficult and time-consuming. In our work, road markings are selected as landmarks due to salient appearance features. Based on the detection results of road markings from the vehicle-borne images, the points of edge lines are employed to fit straight lines with RANSAC for outlier removal. The distances between the ego-vehicle and the fitted edge lines can be computed with camera-vehicle calibration in advance. Subsequently, the point-to-line distances from the sensed data are mapped into global linear constraints on the vehicle’s positions with the support of a lane-level HD map, which provides centimeter-level coordinates of road markings. Finally, the distances and the localization from the integrated navigation system (INS) are fused with the proposed linear Kalman filter based on the second-order Markov model (KF-MM2). The proposed method has been verified in different daily driving scenarios. Experimental results demonstrate that our method can achieve good performance with an average localization error of 0.53 m and a standard deviation of 0.17 m.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-08T11:00:16Z
      DOI: 10.1177/09544070231191156
       
  • Optimal design of rotor structure for vibration and noise reduction in
           electric vehicle generator

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      Authors: Dong Guo, Qingqiao Shi, Yawen Wang, Xiaoting Zhang, Qiping Shen
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In order to reduce the vibration noise of an extended-range electric vehicle (EREV) generator, an optimization method based on changing the rotor structure is proposed in this paper. Firstly, the specific optimization scheme is determined by theoretical and simulation analysis to perform skew pole segmentation of the rotor, while using an eccentric pole arc design to determine the optimal parameters with the target of cogging torque. Then, in order to verify the feasibility of the scheme, the main performance of the generator before and after the optimization is analyzed, including radial electromagnetic force wave, counter-electromotive force (counter EMF), electromagnetic torque, and rotor strength. Finally, a high-precision finite element model of the generator was established, the vibration acceleration, as well as the sound pressure level before and after optimization, were calculated, and a noise test was completed. The results show that the optimized scheme significantly weakened the cogging torque of the generator, while reducing the radial electromagnetic force wave and counter EMF distortion rate to a certain extent, and finally significantly improved the vibration and noise performance of the generator.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-07T10:31:02Z
      DOI: 10.1177/09544070231195403
       
  • A review of research on centrifugal pendulum vibration absorber in the
           field of vehicle power transmission

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      Authors: Guangqiang Wu, Yi Zhang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The centrifugal pendulum vibration absorber (CPVA) is a rotating mechanical device that counteracts order-specific torque fluctuations in a rotating system by the reciprocating motion of multiple mass absorbers on a predetermined path. The downsizing of automotive engines and supercharging technologies have promoted the research and application of CPVA in drivelines. The development of CPVA is reviewed, a variety of typical CPVA structural features are described such as unifilar type, parallel bifilar type, trapezoidal bifilar type, roller type and synchronous type. The non-linear characteristics of the CPVA such as jumps and asynchronous response are discussed in detail. Mathematical methods for establishing and solving the equations of motion, the excitation of the CPVA by the gravity field, modal property analysis, the effect of the type of damping between the damper and the rotor, and the effect of manufacturing deviations on system performance are discussed. The main research results of CPVA are summarized, current research hotspots and difficulties are summarized, future development directions are proposed, and suggestions are made for future research on powertrain electrification.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-07T10:25:41Z
      DOI: 10.1177/09544070231194743
       
  • Use of the best-worst method to evaluate determinants affecting cost
           

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      Authors: Ji-Feng Ding, Cathay Kuo-Tai Kang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      As China is a major automobile manufacturing and consumption country, cost reduction is an important indicator for the operation of the automobile industry. There are many automobile-related components and parts, and each component is important to the full functionality of the automobile. This article focuses on automobiles’ heat exchanger components (HECs) because they have important connections with the engine, transmission, body, and hydraulic systems of automobiles. Since the HECs are important functional parts of automobiles, it is worthwhile to investigate the determinants affecting the cost reduction of HECs in the automobile industry. Hence, the main purpose of this article is to evaluate the determinants affecting the cost reduction of HECs in the Chinese automotive industry using the best-worst method (BWM). Firstly, based on the literature and the opinions of industry and expert interviews, five evaluation dimensions and 20 evaluation factors were developed. Secondly, an empirical survey was conducted using the BWM and expert questionnaires. Finally, the study’s results revealed that: (1) “Research and development” is the most critical evaluation dimension that affects the cost reduction of HECs in the Chinese automotive industry; (2) The determinants affecting the cost reduction of HECs in the Chinese automotive industry were “value analysis/value engineering,”“production system optimization,”“developing industry standards,”“lightweighting,”“synchronous new product development,” and “waste reduction.” The empirical findings showed that the first three determinants were particularly important in the decision-making factors of cost reduction. In addition, this article discusses and suggests these determinants as a reference for future cost reduction evaluation of HECs in the Chinese automotive industry.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-07T10:20:21Z
      DOI: 10.1177/09544070231194373
       
  • A compact hydro-mechanical transmission solution to wheel loader
           propulsion system and its control strategy

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      Authors: Feng Wang, Zhenchuan Lin, Haoxiang Zhang, Chen Zhang, Bing Xu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Given the need for high efficiency to wheel loader powertrain, hydro-mechanical transmission is a promising solution to wheel loader propulsion system since it enables efficient engine operations owing to its continuously variable transmission function. The current hydro-mechanical transmission consists of planetary gear set and two hydrostatic units, making it bulky and complex in controls. This study proposes a simple and compact hydro-mechanical transmission solution to wheel loader powertrain. It improves vehicle acceleration performance by providing hydraulic torque assistance at low vehicle speed. The steady-state characteristics of the proposed hydro-mechanical transmission are analyzed, and the mathematical models of proposed wheel loader powertrain are constructed. An optimization strategy is developed as a reference for the design of an engine-speed based control strategy. The simulation results of the key components of proposed powertrain are analyzed. Furthermore, the engine-speed based control strategy is evaluated by the optimization strategy in different forms of the loading cycles. The results demonstrate the effectiveness of proposed wheel loader powertrain and its control strategy.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-07T10:15:22Z
      DOI: 10.1177/09544070231191157
       
  • An energy saving rule-based strategy for electric-hydraulic hybrid wheel
           loaders

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      Authors: Feng Wang, Qunya Wen, Bing Xu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Recently, hybrid electric vehicles are getting popular as they are both clean and efficient. As one of the hybrid electric powertrains, the battery powered parallel electric-hydraulic hybrid powertrain (PEHHP) is zero emission and has better drive performance. But the energy use of the PEHHP highly depends on the control strategy. A proper energy management strategy is critical for torque distribution and hybrid powertrain efficiency improvement. In this paper, a real-time rule-based strategy is proposed to determine the torque distributions of the PEHHP. The proposed rule-based strategy is based on the component efficiency analysis. And it optimizes the electric motor operating points. Experiments are conducted to show the operation results of the parallel electric-hydraulic hybrid wheel loaders. The powertrain energy use of the proposed rule-based strategy is close to that of the global optimal dynamic programing strategy, with energy use gaps of 2.99%, and 6.10% in simulation and experiment respectively.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-06T06:58:19Z
      DOI: 10.1177/09544070231191843
       
  • Vibration characteristics of electric drive system considering rotor-step
           skewing

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      Authors: Dong Guo, Dongning Huang, Shuaishuai Ge, Yawen Wang, Qiping Shen
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Electric vehicle has been gaining popularity in the worldwide market. The drive system for an electric vehicle usually consists of a permanent magnet synchronous motor (PMSM) and a two-stage gear system. The vibration characteristics of electric drive system is of great importance to the noise and durability performance. Recently, rotor-step skewing has drawn attention as a means to reduce the vibration response for the PMSM, since it can effectively reduce the torque ripple as shown in the previous studies. However, the coupling relationship between the torque ripple and the gear transmission system has not been studied thoroughly. To explore the influence of torque ripple on the motor-gear system when considering rotor-step skewing, this paper proposes a coupled electro-mechanical system model to study the vibration characteristics of electric drive system. The effect of rotor-step skewing on cogging torque and torque ripple of PMSM, dynamic transmission error (DTE) of gear transmission system, and vibration characteristics of electric drive system is studied. The simulation results show that the torque ripple has a significant effect on the DTE and the vibration responses of the electric drive system. The rotor-step skewing not only effectively suppress the torque ripple, but also optimize the DTE harmonics induced by the torque ripple.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-05T10:48:26Z
      DOI: 10.1177/09544070231190975
       
  • M-BWR model of accumulator considering delay time

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      Authors: Gege Ye, Yuelin Yang, Yunchao Wang, Zhichao Hu, Heng Du, Xiaoyu Wei
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      To address the limitations of the BWR (Benedict-Webb-Rubin) model in predicting the trend of the real gas pressure in the accumulator under the medium and high frequency domain, sinusoidal excitation experiments with different frequencies are conducted for the bladder type accumulator. Based on the delay phenomenon of the accumulator found in the experiment, the M-BWR model considering the delay time is proposed. To verify the accuracy of the model, the predicted results of the M-BWR model and the BWR model are compared with the experimental results. The results of the comparative analysis show that the average error between the prediction results of the M-BWR model and the experimental results at different frequencies is less than 8%, which meets the requirements of engineering applications.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-05T09:04:14Z
      DOI: 10.1177/09544070231196356
       
  • Energy management strategy of fuel cell vehicles with hybrid energy
           sources: A novel framework via deep reinforcement learning and transfer
           learning

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      Authors: Jianhao Zhou, Aijun Guo, Jie Wang, Chunyan Wang, Wanzhong Zhao
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      This study presents a multicriteria energy management strategy (EMS) for hybrid energy sources (HES) composed of fuel cell/battery/supercapacitor hybrid power system for logistics trucks, which uses a model-free deep reinforcement learning (DRL) algorithm, namely deterministic strategy gradient (DDPG), to improve the portability and reusability of the system. The proposed EMS is capable of reducing the hydrogen consumption cost, the degradation of fuel cell and battery, as well as sustaining the state of charge (SOC) of battery and supercapacitor. The results of the study found that the total cost was reduced by 9.5% compared to equivalence consumption minimization strategy (ECMS) based EMS under the WLTP driving cycle. A novel deep transfer learning (DTL) based framework for DRL-based EMS is further elaborated and evaluated by four metrics. Two DTL techniques including policy transfer and experience transfer are leveraged to transfer the EMS from original logistic truck to a B-class passenger car powered by fuel cell and battery. The results indicate that the proposed DTL framework is an appropriate approach to transfer EMSs from different vehicle model with various power topology. The convergence speed of DTL-based EMS is apparently accelerated over 50% in comparison to DRL-based EMS. Besides, the fuel optimality, robustness, convergence, and generalization stability for DTL-based EMS is also improved.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-05T07:44:11Z
      DOI: 10.1177/09544070231195402
       
  • Identification of pedestrian motion feature in mixed traffic conditions
           and anti-collision algorithm of autonomous vehicle

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      Authors: Chaochun Yuan, Xinkai Wu, Jie Shen, Long Chen, Yingfeng Cai, Youguo He, Shuofeng Weng, Yuqi Yuan, Yuxuan Gong, Jinhang Song
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      To improve the safety of pedestrians crossing the road in the mixed traffic conditions, this study proposed an active collision avoidance method based on the prediction of pedestrian trajectory. A convolutional neural network is applied to identify the motion feature of pedestrians crossing the road in the image of an automated driving environment with vehicular sensors. Then combined with the pedestrian motion parameters, a new Kalman filtering algorithm is proposed to analyze the change of pedestrian motion feature and predict the trajectory of the pedestrian. Furthermore, a PDS (Pedestrian, Distance, and Speed) estimated braking distance model based on pedestrian characteristics, the distance between pedestrian and vehicle, and the speed of the vehicle is established in this study for the autonomous vehicle controlling speed in advance to avoid risks. It improves both the crossing road pedestrian safety and efficiency of traffic. Eventually, simulations based on CarSim/Simulink are designed to verify the validity of the method. Results show that the method proposed can effectively predict pedestrian trajectories and realize active collision avoidance under the time delay of the detection link.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-05T07:37:57Z
      DOI: 10.1177/09544070231194736
       
  • A novel Taylor expansion based filter for localization of land-vehicles

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      Authors: Meihong Zhao
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      This technical note introduces a localization method for land-vehicles based on dead-reckoning and nonlinear filter. To address the chattering phenomenon during vehicle rotating, we derive a novel dynamic model by combining lateral motion and wheel dynamics. By introducing a Taylor moment expansion method, a novel nonlinear filter framework is proposed for vehicle localization. Simulation and experimental demonstrate that the proposed scheme for land-vehicles provides considerable results in accuracy than other state-of-the-art methods.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-09-05T07:20:33Z
      DOI: 10.1177/09544070231192726
       
  • Design and implementation of an adaptive headlight system model for
           enhanced night-time driving safety

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      Authors: Semanpreet Singh, Utkarsh Sharma, Ishant Kasana, Sayan Sadhu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Driving at night poses a serious risk due to the momentary blindness brought on by oncoming traffic’s headlights. Traditional headlight designs impair vision temporarily, which increases the risk of accidents. Manual headlight settings and inadequate lighting make the issue worse. An in-depth review of the various sensors-based headlight control systems used by various automaker firms has been conducted. This study discusses a system for detecting vehicles that makes use of a camera and a regression-based machine-learning model. Using a grid formation technique on video that the on-board camera has processed, the position of the approaching vehicle is determined. A signal is then sent to a reflector system that has been specially designed to enable precise beam control with the help of a control unit made up of several electronic components, such as an Arduino UNO, a relay, and a battery. The proposed technology can increase nighttime driving safety by eliminating the Troxler effect on drivers of opposing vehicles while retaining adequate road illumination for the driver on-board.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-08-30T11:33:25Z
      DOI: 10.1177/09544070231194744
       
  • An adaptive robust path-tracking control algorithm of multi-articulated
           and redundantly actuated virtual track train

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      Authors: Zhonghua Zhang, Caijin Yang, Weihua Zhang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Multi-articulated and redundantly actuated virtual track trains (VTTs) are inevitably exposed to unknown exogenous disturbances and various operating conditions. To address the complex over-actuated tracking-control problem, this study proposes a decoupling control scheme for an all-wheel independent drive and all-wheel active steering VTT composed of multiple modules, wherein the adaptive robust path-tracking and longitudinal speed control algorithms of the VTT are decoupled. An appropriate control-oriented nonlinear dynamic model for VTT path-tracking control is formulated using Lagrange’s equations. To compensate for the model uncertainties and environmental disturbances without priors and parameter estimations, a robust control algorithm using radial basis function neural network and sliding mode is proposed. The asymptotic stability of the algorithm is proved, and its adaptation law is derived using the Lyapunov theory. Moreover, a novel traction/braking control algorithm based on the wheel speed distribution model and double closed-loop control algorithm is suggested. Using a multi-body dynamic model of the VTT with seven modules, simulations are performed to evaluate the effectiveness and superiority of the proposed path-tracking algorithm. The obtained results indicate that the proposed algorithm could realise the expectable performance of the VTT path tracking and longitudinal speed control. Moreover, the proposed control algorithm has good scalability for multi-articulated and redundantly actuated VTT.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-08-29T07:03:15Z
      DOI: 10.1177/09544070231192728
       
  • Intelligent vehicle path tracking control strategy considering data-driven
           dynamic stable region constraints

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      Authors: Yihang Li, Guangqiang Wu, Kai Liu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The path tracking controller can easily reduce the tracking error, but often exceed the limitations of vehicle stability. In this paper, an intelligent vehicle path tracking control strategy considering data-driven dynamic stable region constraints is proposed. Firstly, based on the two-degree-of-freedom (DOF) vehicle model and nonlinear tire model, the vehicle sideslip angle-sideslip angular velocity ([math]) phase plane is established. Then, the stable region dataset is made considering the influence of vehicle speed, adhesion coefficient, and front wheel angle. To get the vehicle driving stable region, a back propagation neural network (BP-NN) regression model is trained offline. Subsequently, a path tracking control strategy based on adaptive-model predictive control (MPC) is designed, which considers the vehicle dynamic stable region constraints with the BP-NN predicting online. Finally, model-in-the-loop (MIL) and driving simulator is designed to test the control strategy, which indicates that it has a better performance compared with the linear quadratic regulator (LQR) path tracking controller.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-08-18T11:27:38Z
      DOI: 10.1177/09544070231193178
       
  • Design principles and traction performance of a novel zero-spin rolling
           conical traction continuously variable transmission

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      Authors: Chao Li, Hongmei Liu, Hao Gao, Yuanfa Zhao, Teng Xiang, Qingtao Li
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In the existing traction continuously variable transmission (CVT), half toroidal CVT (HT-CVT) is considered to have a better traction performance. However, the HT-CVT has the spin losses due to its structural limitations, which significantly influences the traction efficiency. In this paper, the kinematic qualities and contact models of a novel zero-spin rolling conical CVT (RC-CVT) are studied, and then the rollers and conical disks are compactly designed through the proposed design principles. Subsequently, the transmission efficiency is investigated by using a detailed numerical model and compared with HT-CVT. Based on these computational models and parameters, the practical spin ratio, spin momentum and traction efficiency of RC-CVT are calculated and compared with HT-CVT. The results show that the practical spin ratio and spin momentum of RC-CVT are much smaller than that of HT-CVT, and the efficiency on fixed transmission ratio is consequently higher than that of HT-CVT.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-08-18T11:19:53Z
      DOI: 10.1177/09544070231190782
       
  • Energy-efficient adaptive cruise control system with acceleration
           prediction via long short-term memory

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      Authors: Shunming Jiang, Qinghui Zheng, Kuo Wu, Pengpeng Wu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      An energy-efficient adaptive cruise control (ACC) system that predicts the preceding state is proposed to meet the demands of driving in different states and working conditions. The long short-term memory (LSTM) network predicts the trajectory of the preceding vehicle’s future acceleration, allowing for an adaptive time headway that takes acceleration into account. The acceleration of the preceding vehicle is also incorporated as an augmented state in the deep deterministic policy gradient (DDPG) algorithm, resulting in a combined algorithm called prediction deep deterministic policy gradient (PDDPG). A multi-objective reward function is constructed based on human driving data to evaluate the performance indexes of vehicle longitudinal control, including efficiency, safety, and economy. The rules for changing the weight of each target performance under various typical cycle conditions are determined through experiments. The Carsim-based urban, suburban and highway conditions together with the Simulink vehicle dynamics model are compared with human driving data and ACC of conventional algorithms. Based on the test results, the proposed algorithm can improve fuel efficiency by 19.36% in urban driving conditions and reduce acceleration fluctuations.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-08-17T11:24:41Z
      DOI: 10.1177/09544070231190959
       
  • Control of four-wheel steering vehicles based on composite model free
           observer

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      Authors: Guowang Zhang, Xiangyu Wang, Liang Li
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Four-wheel steering (4WS) is an advanced technology for automotive chassis, which is more flexible and redundant than conventional front wheel steering. For a 4WS vehicle, the accuracy and stability of steering control must be guaranteed, so the main difficulty is the model nonlinearity during driving. To deal with the problems, a novel composite model free observer (CMFO) is designed. The nominal parameters are used to model the 4WS vehicles, and the data-driven method is used to improve observation accuracy. Then a CMFO based controller is designed to control the lateral dynamics of 4WS vehicles. The stability of the proposed control scheme is proved by theoretical derivation, and experiments are carried out to compare the performance between the CMFO based controller, model free adaptive controller (MFAC) and linear quadratic regulator (LQR). The mean absolute error (MAE) values of CMFO are reduced by 75.56% and 44.49% compared with those of LQR and MFAC, respectively.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-08-17T11:14:33Z
      DOI: 10.1177/09544070231190676
       
  • Design and comparative study of steering controller for tracked vehicle
           based on disturbance observation

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      Authors: Xuzhao Hou, Yue Ma, Changle Xiang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Tracked vehicles are suitable for rough, low-bearing ground or complex environments because of the large contact area and low pressure between tracks and the ground, and the great obstacle crossing and avoidance capabilities of tracked vehicles. For fast and safe turns, an advanced steering controller is required to achieve precise tracking and stability under system uncertainty. In this study, a steering controller is proposed for tracked vehicles by combining a parameter adaptive law and a second order disturbance observer (DO-2). The friction coefficient between track and ground is estimated online as an uncertain parameter. Random disturbance and function uncertainty are resisted by DO-2. Using Lyapunov’s theory, the input-state stabilities of DO-2 and the closed loop system are proved under random disturbance. A sufficient condition is proposed to check the stability of the system under function uncertainty. Field tests are carried out on rough and slippery grounds using a small-scale electric tracked vehicle. Compared with the controllers based on first order disturbance observer (DO-1) or linear extended state observer (LESO), the optimized DO-2-based steering controller has a smaller root-mean-square error of yaw rate tracking. Adaptive law improves tracking accuracy by 22% on slippery ground.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-08-10T08:42:38Z
      DOI: 10.1177/09544070231190135
       
  • Slip ratio adaptive control for distributed drive electric vehicle based
           on wheel speed

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      Authors: Qiping Chen, Liang Huang, Lu Gan, Sheng Kang, Rui Wan
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Aiming at the problems of poor control effect and poor robustness for distributed drive electric vehicles driving on complex and changeable roads, this paper proposes a slip ratio adaptive control method based on wheel speed. Firstly, an optimal slip ratio estimator considering axle load transfer was developed by analyzing the single-wheel dynamics of the vehicle and based on the Burckhardt tire model. Secondly, a cubic polynomial function is used to fit and optimize the optimal slip ratio-peak adhesion coefficient curve, which effectively improves the accuracy of obtaining the optimal slip ratio. Then, a conditional integral sliding mode controller based on wheel speed is designed in order to enhance the transient characteristics of the sliding mode control, to avoid integral saturation, and to improve the control effect of the sliding ratio controller in the low speed start-up phase. Finally, three typical working conditions, namely single road, flat road, and slip road, were established for simulation and experimental validation. The results show that the method in this paper is able to estimate the optimal slip ratio of the road in real time, realize the wheel slip ratio adaptive control, and improve the dynamic performance and lateral stability of distributed drive electric vehicle.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-08-09T11:51:49Z
      DOI: 10.1177/09544070231189903
       
  • Thermodynamic analysis of heat transfer reduction in spark ignition using
           thermal barrier coatings

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      Authors: Brian Gainey, John Gandolfo, Zoran Filipi, Benjamin Lawler
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      This work uses a 0D thermodynamic engine model coupled to a 1D surface temperature solver to study the potential of low thermal inertia thermal barrier coatings (TBCs) on combustion chamber surfaces to increase the efficiency of spark ignition engines. Under ideal conditions, coating the piston crown, head, and valve faces with a TBC with a thermal inertia of 640 J/m2 K s1/2 resulted in less than a 1% relative improvement in efficiency. Despite using a low thermal inertia coating to avoid open cycle charge heating, the reduction in closed cycle heat transfer, which is the pathway to increasing efficiency, increased knock propensity. Therefore, any efficiency gain through closed cycle heat transfer reduction in spark ignition is offset by the need to retard spark timing to counter knock. An exergy analysis of completely blocking heat transfer for a 10 crank-angle degree window showed that on a low compression engine, like those used for stoichiometric gasoline spark ignition, the maximum efficiency gain achievable was limited compared to a higher compression ratio engine. Furthermore, the high gas temperatures of stoichiometric operation mean that even state-of-the-art TBCs cannot elevate surface temperatures enough purely through temperature swing to achieve a significant reduction in heat transfer near top dead center, where work availability is highest. Overall, these results indicate that low thermal inertia TBCs are ill-suited for achieving an efficiency benefit in spark ignition through a heat transfer reduction pathway. Instead spark ignition TBC research should explore ways to use low thermal inertia TBCs to achieve open cycle charge cooling to reduce knock propensity.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-08-07T10:56:50Z
      DOI: 10.1177/09544070231189545
       
  • Vehicle stability control strategy for high-speed curves based on mode
           switching

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      Authors: Taiping Yang, Peiqing Li, Qipeng Li, Zhuoran Li
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      This study aims to design a mode-switching control system based on a non-singular fast terminal sliding mode (NFTSM) algorithm for the lateral stability problem of vehicles driving in high-speed curves. First, a three-degrees-of-freedom model of the vehicle was established, and a predicted lateral load transfer ratio (PLTR) was proposed as a threshold for dividing the lateral stability index based on the conventional PLTR. Second, for the vehicle driving state in which the vehicle does not satisfy the PLTR threshold, the vehicle lateral deflection angle is adjusted based on the NFTSM controller to improve the bending path-tracking accuracy of the vehicle. For the vehicle critical rollover state that satisfies the PLTR threshold, an NFTSM-based additional yaw moment control algorithm is proposed to estimate various unknown disturbance and parameter ingestion terms in the vehicle modeling process using an adaptive radial basis function neural network and adaptively adjust the key parameters of the NFTSM controller. Finally, a joint Carsim-Simulink simulation model was built to verify the control algorithm proposed herein. The simulation results show that the mode-switching control system can improve the vehicle’s yaw and rollover stability in high-speed curves and prevent the occurrence of rollover.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-08-03T12:14:48Z
      DOI: 10.1177/09544070231185170
       
  • Development of a new seat isolation system for ameliorating the
           driver’s ride quality

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      Authors: Jinyu Jiang, Vanliem Nguyen, Renqiang Jiao, Jili Zha, Yundong Mei
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      This study proposes the seat’s three isolation systems including the three parallel isolations (TPI), the quasi-zero stiffness structure (QSS) embedded in the seat’s isolation system, and a combination of the QSS and TPI (QSS-TPI) for ameliorating the ride quality of the driver. From the dynamic models of the TPI, QSS, and QSS-TPI established, their parameters are optimized and simulated to compare the performance between the TPI, QSS, and QSS-TPI in isolating the driver’s vibration. The root mean square values of the vertical acceleration (azs), pitching acceleration (aφs), and rolling acceleration (aθs) of the seat have been selected as the objective functions. With optimized parameters of TPI, QSS, and QSS-TPI optimized, the research results show that the vertical acceleration of the seat using the optimized QSS is lower than that of the optimized TPI, conversely, both the pitching and rolling seat accelerations using the optimized TPI have been strongly decreased compared to the optimized QSS. With the optimized QSS-TPI, the azs is greatly reduced by 55.84% in comparison with the optimized TPI while both the aφs and aθs are strongly decreased by 98.76% and 98.46% compared to the optimized QSS. This means that the seat’s QSS-TPI ameliorate the driver’s ride quality and shaking better than that of both the seat’s TPI and QSS. From the simple structure and isolation performance of the QSS-TPI proposed, the seat’s QSS-TPI should be applied to the seat’s isolation system to ameliorate the driver’s ride quality.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-08-03T05:17:48Z
      DOI: 10.1177/09544070231190677
       
  • Trajectory planning approach for autonomous electric bus in dynamic
           environment

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      Authors: Ahmed Waleed, Sherif Hammad, Mohamed Abdelaziz, Shady A Maged
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Path planning is a challenging task to achieve vehicle autonomy, and it becomes even more difficult in handling dynamic situations and big vehicle sizes. Its performance is affected by the accuracy of mapping and vehicle localization. Many path planning algorithms have been developed to address static environments, however, these do not accurately reflect real-world scenarios which are dynamic in nature. This paper introduces a new planning architecture consisting of a global planner that plans a path in an occupancy grid map generated using LIDAR and odometry data. The local planner uses this global plan and plans a local plan on a section of the map that takes into consideration dynamic obstacles. Both the local and global plans are used to calculate the optimum velocity profile, providing a feasible and comfortable trajectory. The trajectory is then fed to a predictive Stanley controller, and both the calculated steering angle and the optimum velocity are achieved by low-level controllers. The performance of the proposed architecture was tested on a golf bus in a constrained environment and compared to different manual driving attitudes using a key performance indicator. The results of the proposed architecture show that it has a better KPI, with an average of 37% better than manual driving.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-08-02T11:30:28Z
      DOI: 10.1177/09544070231189765
       
  • Study on multi-closed loop control of electro-mechanical braking for
           electric vehicles based on clamping force

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      Authors: Qiping Chen, Zongyu Lv, Haiyang Tong, Dequan Zeng, Lu Ouyang, Qin Liu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In order to improve the clamping force control accuracy of electro-mechanical braking system of electric vehicles, a multi-closed loop control strategy of electro-mechanical braking based on clamping force is proposed. A detailed EMB mathematical model is established. The sliding mode speed controller and improved fuzzy PID clamping force controller are designed, and the joint simulation model of the speed the clamping force controller is established, and simulation experiments are used to verify the effectiveness of the control strategy. Comparative analysis of three simulation conditions, the maximum adjustment time of the proposed control strategy is 0.254 s and the maximum overshoot is 0.45%. The results of research show that the control strategy designed in this paper can quickly and stably reach the target value of clamping force, has a strong anti-interference capability, has some reference value in the electric vehicle braking control.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-08-02T11:25:47Z
      DOI: 10.1177/09544070231189766
       
  • Multi-attention network for pedestrian intention prediction based on
           spatio-temporal feature fusion

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      Authors: Xiaofei Zhang, Xiaolan Wang, Weiwei Zhang, Yansong Wang, Xintian Liu, Dan Wei
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      An essential prerequisite for autonomous vehicles deploying in urban scenarios is the ability to accurately recognize the behavioral intentions of pedestrians and other vulnerable road users and take measures to ensure their safety. In this paper, a spatial-temporal feature fusion-based multi-attention network (STFF-MANet) is designed to predict pedestrian crossing intention. Pedestrian information, vehicle information, scene context, and optical flow are extracted from continuous image sequences as feature sources. A lightweight 3D convolutional network is designed to extract temporal features from optical flow. Construct a spatial encoding module to extract the spatial features from the context. Pedestrian motion information are re-encoded using a collection of gated recurrent units. The final network structure is created through ablation research, which introduces attention mechanisms into the network to merge pedestrian motion features and spatio-temporal features. The efficiency of the suggested strategy is demonstrated by comparison experiments on the datasets JAAD and PIE. On the JAAD dataset, the intent recognition accuracy is 9% more accurate than the existing techniques.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-08-02T11:22:29Z
      DOI: 10.1177/09544070231190522
       
  • Improved convolutional neural network and spectrogram image feature for
           traffic sound event classification

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      Authors: Ke Xu, Jingyi Yao, Lingyun Yao
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In recent years, Sound Event Classification (SEC) is a remarkable field of computer audition research. The abilities to automatically capture and classify sound events are meaningful for expanding the auditory ability of autonomous vehicle in a complex driving environment. The Autonomous vehicles will encounter some special road conditions during driving, such as large truck occlusion, tunnels, and buildings that hinder radar detection. Therefore, the perception capabilities of on-board lidar, vision, and other sensors are impacted, resulting in a great threat to the safe driving of the car. At this time, auditory environment perception can provide auditory dimension information for the vehicle. However, with the increase of noise level, the SEC task of autonomous vehicle becomes seriously difficult. Traditional machine learning methods show weak robustness in the highly noisy environment. In this work, an autonomous vehicle Sound Event Classification (AVSEC) framework based on Spectrogram Image Features (SIFs) and Convolutional Neural Networks (CNN) algorithm is proposed to solve the SEC question. Further on, the ambulance, bus, civil defense siren, fire truck, screaming, etc. are taken as the research traffic sounds. Traffic Sound Datasets (TSD) are collected, augmented and customized. Then, directly connected channel (DCC) between convolutional blocks and Convolutional Block Attention Module (CBAM) are designed to optimize the neural network. Testing results show that the AVSEC system achieves an accuracy of 97.18%. Furthermore, the results of AVSEC and other machine learning methods are compared, which shows that the combination of SIFs and AVSEC-net provides better noise robustness and classification accuracy in AVSEC task. The sound classification algorithm designed in this paper, as an advanced auxiliary driving system for sound detection, can identify the sound types in the current traffic environment of the Autonomous vehicles, that is, the traffic scene category. The vehicle computer can remind the driver to pay attention to driving safety through the above sound types, so as to improve the safety of the driver and the vehicle.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-08-02T06:10:46Z
      DOI: 10.1177/09544070231189910
       
  • Potential of adhesive bonding technology for joining thermo-mechanically
           modified wood composites in automotive application

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      Authors: Moira Burnett, Martin Kahlmeyer, Christin Koch, Andreas Winkel, Stefan Böhm
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Wood composites are a sustainable alternative to lightweight materials, but most often only possess low to medium mechanical properties. The stiffness and strength of wood-based panels can however greatly be enhanced by a densification process. In this context the question arises as to whether the increase in density and the associated compaction of the cell structure have a lasting effect on the adhesion of binders and the overall bonding ability. This paper therefore investigates the extent to which thermo-hydro-mechanical compression at different pressure levels affects the adhesive infiltration into laminated beech veneer composites. For this purpose, not only the mechanical properties of the plywood are analysed, but also the infiltration of polyurethane and polyvinyl acetate adhesives by fluorescence microscopy. Results show that although the infiltration capacity of the adhesives is impaired by the densification, higher degrees of compression are also accompanied by superior mechanical properties.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-29T10:20:09Z
      DOI: 10.1177/09544070231187690
       
  • A new lateral force estimator for intelligent tires based on
           three-dimensional ring model

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      Authors: Delei Min, Yintao Wei, Feng Wang, Bo Lu, Shibin Zhu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Tire lateral forces have an important impact on vehicle stability and vehicle ride comfort. In general, the intelligent tire lateral forces are estimated using lateral nodal displacements or data-based methods, which are easily disturbed by measurement noises and lack accuracy in the case of small test numbers. This paper proposes a model-based lateral force estimator for intelligent tires, which includes a mathematical model, a signal processing algorithm, and a Kalman Filter. As the core of the lateral force estimator, the mathematical model is proposed based on the three-dimensional ring model and can describe the analytical relationship between the lateral acceleration signal and the lateral force. Based on the mathematical model, the optimal state observation of the intelligent tire lateral forces is realized using a Kalman Filter. The performance of the lateral force estimator is validated through lateral slip tests under two different vertical loads performed on the MTS Flat Trac III test bench. The results show that the lateral force estimator’s average normalized root mean square (NRMS) error is 5.83%. Compared with the data-based and model-based methods in previous studies, this model-based lateral force estimator provides an efficient method to estimate the intelligent tire lateral forces using fewer tests.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-29T10:17:10Z
      DOI: 10.1177/09544070231186703
       
  • Numerical study on the effect of a two-stage pilot injection strategy on
           the performance of medium-speed diesel/natural gas dual-fuel marine engine
           

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      Authors: Longlong Jiang, Ge Xiao, Wuqiang Long, DongSheng Dong, Jiangping Tian, Hua Tian, Baofu Jia, Shanggang Yang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The need to reduce marine engine emissions continues to grow with the implementation of stricter emission standards. Numerical simulations were conducted to study the effect of a two-stage pilot diesel injection strategy on combustion and emissions in a medium-speed diesel/natural gas dual-fuel marine engine. A comprehensive analysis was performed on the start of the first pilot diesel injection (SOI1) and the proportion of the first pilot diesel injection (POI1), identified as two coupling factors of the injection strategy. The results indicated a significant improvement in indicated thermal efficiency (ITE) of over 48% and a reduction in nitrogen oxide (NOx) emissions of over 50% compared to the baseline single-stage injection strategy can be achieved through the use of high POI1 and delayed SOI1. In addition, the first pilot diesel spray covered the squish and piston bowl regions, enhancing the reactivity of the fuel-air mixture in these regions. The mass fraction of CH2O and H2O2 radicals determined the distribution of reactivity in different regions and characterized the transition process from low-temperature reaction to high-temperature reaction. The strategy of high POI1 and delayed SOI1 resulted in a better low-temperature reaction distribution, reducing combustion duration, improving ITE, and decreasing NOx, HC, CO emissions at medium load condition.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-25T12:32:25Z
      DOI: 10.1177/09544070231188873
       
  • Development of a dynamical model and energy analysis for wheel loader

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      Authors: Gaonan Zhao, Connor P Edson, Jie Yao, Zongxuan Sun, Kim A Stelson
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The objective of this paper is to develop a fully integrated model for the wheel loader, including the subsystem dynamics of the engine, drivetrain, working circuit, steering circuit, and vehicle. It leads to a high-order strongly nonlinear system, and all state variables are coupled together to form a Multi-Input and Multi-Output (MIMO) system. A control architecture is proposed to decouple the MIMO system into several Single-Input and Single-Output (SISO) systems. A tracking problem has been formulated to validate this fully integrated model with the field test data. The accuracy of the model is verified by the 2.3% difference between the measured and simulated fuel consumption. Meanwhile, an energy distribution analysis is conducted to reveal the energy consumption and energy loss of each portion of the wheel loader. Such a model can be used to plan the working pattern, guide the driving habits of human operators, or refine the underlying architecture, leading to the ultimate goal of reducing total fuel consumption and improving productivity.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-25T12:18:47Z
      DOI: 10.1177/09544070231188772
       
  • Interactive on-ramp merging decision-making with motion prediction
           considering merging motivation

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      Authors: Jinqiang Liu, Wanzhong Zhao, Chunyan Wang, Yuning Zhou, Ziyu Zhang, Yajuan Qin
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      On-ramp is one of the scenarios most likely to cause traffic accidents and congestion. In order to mitigate the conflict between mainline vehicles and ramp vehicles, and improve vehicle safety and travel efficiency, we propose an interactive on-ramp merging decision-making (IORMDM) method based on motion prediction. We first propose a motion prediction method for different actions of vehicles based on model predictive control. Meanwhile, the game theory is employed to construct the interaction behavior between the ramp vehicle and the mainline vehicle, and the merging motivation of the ramp vehicle is modeled to describe the collision risk between it with the end of the acceleration lane. Afterward, according to the predicted trajectories of vehicles, the comprehensive payoff of vehicle collision risk, efficiency, passenger comfort, and merging motivation of each action is solved. The Nash equilibrium solution is solved to determine the optimal action of each vehicle according to the payoff table. Simulation experiments demonstrate that our proposed method could reduce collision risk and improve traffic efficiency.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-24T06:43:53Z
      DOI: 10.1177/09544070231187687
       
  • Coordinated control of AFS and DYC for electric vehicles with mechanical
           elastic electric wheels considering the roll effects and uncertain
           parameters

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      Authors: Danyang Li, Youqun Zhao, Fen Lin, Chenxi Zhang, Tao Lin
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In order to improve the lateral stability of in-wheel motors electric vehicles (IMEV) equipped with mechanical elastic electric wheels (MEEW) under extreme conditions, this paper proposes an integral sliding mode control (ISMC) algorithm based on the coordination of active front steering (AFS) and direct yaw moment control (DYC) considering the roll effects and the uncertainty of tire cornering stiffness. Firstly, the AFS control algorithm based on adaptive integral terminal sliding mode is proposed, which uses radial-basis-function neural network (RBFNN) to adaptively approximate the integrated nonlinear unknown disturbance. Secondly, considering the roll effects and uncertain cornering stiffness, a mismatched uncertain system for integrated control of AFS and DYC is established. An integral sliding mode control algorithm based on linear matrix inequality (LMI) is designed, and the asymptotic stability of sliding mode dynamics is proved. Further, a constraint optimization algorithm is used to distribute the additional yaw moment. Then, a coordinated control strategy based on the elliptical stable region of the phase plane and the rollover index is designed to activate the integrated controller of AFS and DYC at the right time. Finally, the effectiveness of the control algorithm is verified by high-fidelity CarSim-Matlab simulations. The results show that the proposed controller can effectively and robustly ensure the vehicle lateral stability under extreme conditions.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-24T06:31:32Z
      DOI: 10.1177/09544070231188360
       
  • Vehicle motion trajectory prediction fusion algorithm with driver
           adventurousness correction factor based on CS-LSTM

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      Authors: Pengbo Xiao, Hui Xie, Long Yan
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Predicting the trajectories of adjacent vehicles plays an important role in the driving safety of adaptive cruise control system. It affects the safety and stability of the vehicle following the target vehicle during the vehicle cruising driving vehicle. However, due to the uncertainty of vehicle dynamics, driver character, and the complexity of the surrounding environment, vehicle trajectory prediction faces great challenges. Hence, a dynamic vehicle trajectory prediction system is proposed based on identifying driver intentions. First, based on a convolution LSTM, the driver adventurousness factor is introduced to describe the driver’s lane-change behavior heterogeneity and improve the accuracy of long-term lane-change trajectory prediction of adjacent lane vehicles. Second, the trajectory prototype predicted trajectory is updated by adjusting the minimum value function until the vehicle model corresponds to the planned sampling trajectory to improve the accuracy of the adjacent lane vehicle’s short-term lane-change trajectory prediction. Finally, the trajectories are fused using the trigonometric fusion algorithm, and the optimal trajectory is the output. The suggested strategy can predict lane-change intentions 2–5 s in advance. The prediction accuracy of the lane-change trajectory was approximately 21% higher than the normal prediction outcomes. The proposed method can be used to improve passenger comfort and the stability of a vehicle following a target vehicle that is separated from the adjacent lane vehicle.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-24T06:26:33Z
      DOI: 10.1177/09544070231188783
       
  • A phase plane H∞ controller for distributed drive electric vehicles with
           stability enhancement based on tire road friction coefficient estimation

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      Authors: Ruijun Zhang, Wanzhong Zhao, Chunyan Wang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      An H∞ control strategy based on the phase plane method (phase plane H∞ controller) tracking two degrees of freedom (DOF) ideal vehicle trajectory scheme is designed for distributed drive electric vehicles with stability enhancement. Firstly, an Extended Kalman Filter (EKF) tire road friction coefficient estimation method based on Keras neural network is presented to accurately and efficiently identify the tire road friction coefficient, taking into account the huge influence of the tire road friction coefficient on vehicle equilibrium point and stability region. Secondly, the phase plane method is applied to provide a dynamic stability boundary for the switching control strategy of direct yaw moment for different tire road friction coefficients; Furthermore, based on the dynamic stability boundary, the weighted phase stability is applied to achieve more realistic stability evaluation criteria, and the fuzzy control strategy is adopted to carry out the feedback regulator of the target side slip angle and yaw rate on the purpose of limiting its maximum value max (β) and max (ωr). Then the torque of the four-wheel was optimized by the quadratic programming method. Finally, the presented method is verified and the results indicate that: (1) the phase plane H∞ control has the advantage in terms of stability and maneuvering performance. More importantly, under a low tire road friction coefficient, the amplitude of the side slip angle is decreased by 26.52% over the H∞; (2) the designed EKF based on Keras neural network parameter correction has a quick and accurate performance in identifying the tire road friction coefficient, and the steady-state error does not exceed 3.25%.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-22T10:53:18Z
      DOI: 10.1177/09544070231187464
       
  • Chebyshev polynomials based compensator design via higher order sinusoidal
           input describing functions in traction motor drive to improve performance
           of electric vehicle

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      Authors: Deniz Kaptan, Buse Tacal Ucun, Levent Ucun
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In electric vehicles (EVs), the efficient selection of the basic elements and the control of the electric motor and the overall system is vital to extend the performance of the vehicle. A feedback control loop with proportional-integral (PI) controllers is usually used in the control of electric motors. Within the scope of this study, the system is handled with frequency-based methods and it is aimed to reduce the performance degrading effect on the system output. In this study, Higher Order Sinusoidal Input Describing Functions (HOSIDFs) are used in order to improve the performance of EVs. Here, the EV is modeled as a Lur’e-type system and a compensator is designed within the PI speed control loop of the electric motor by using Chebyshev polynomials. The optimal coefficients of the Chebyshev polynomials-based compensator minimize the cost function which is related to the harmonics of the system output. This work introduces a novel approach for controlling the traction motor of EVs using a frequency-based method through HOSIDFs. The objective is to enhance the performance of the drive system. Throughout this study, it is also aimed to improve the consumption of the battery and passenger comfort. The results and success of the proposed method are illustrated in time-domain and harmonic plots.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-22T10:47:59Z
      DOI: 10.1177/09544070231186844
       
  • Investigation of unsteady conjugate heat transfer for a radial turbine
           with impingement cooling

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      Authors: Chao Ma, Han Zhang, Zhifu Zhu, Xiaoli Wang, Jianjian Zhang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      For radial flow turbines, raising the temperature before the volute is also an important means of improving their thermal efficiency. As with axial flow turbines, excessive thermal load requires the application of cooling technology. In the study, impingement cooling technology was applied to a radial turbine, and the cooling effect of the turbine was investigated using conjugated heat transfer (CHT) simulations and experiments. The results showed that some of the coolant moved down into the back-disc heat shield cavity and impinged onto the back-disc. Most of the coolant eventually flowed into the rotor flow passage and stayed close to the blade suction side. The blade leading-edge shroud was the worst cooled area, but some temperature reduction was achieved. An experimental investigation was conducted with a high-speed infrared camera at much-reduced turbine speeds of 5000 and 10,000 rpm. The experimental results confirmed the numerical findings, and it was also found that cooling becomes more effective with the increase of turbine speed and of coolant relative mass flow. A 30°C reduction of blade leading-edge temperature was achieved with 3% relative coolant mass flow at 10,000 rpm.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-21T12:37:53Z
      DOI: 10.1177/09544070231187507
       
  • Navigating autonomous vehicles in uncertain environments with
           distributional reinforcement learning

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      Authors: Shuyuan Xu, Jiachen Hao, Xuemei Chen, Yuhui Hu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Navigation in complex urban environments is very difficult, mainly due to perceptual uncertainty caused by obstructions in the field of view. The perceptual uncertainty is mainly due to sensors obstructed by obstacles. This has a significant impact on the safety of autonomous vehicles. Existing approaches based on partially observable Markov decision processes or reinforcement learning for the uncertainty problem may lead to conservative planning and expensive computation. We propose caution-driven networks combined with distributional reinforcement learning fully parameterized quantile function, which termed Intrinsic caution module – fully parameterized quantile function (ICM-FQF). The method is also applied in the continuous action space. The method is used to evaluate two challenging scenarios, pedestrians crossing with occlusion and a unsignalized intersection with a limited field of view. The algorithm is trained and evaluated using the CARLA simulator. Compared to conventional RL algorithms, the method makes smarter decisions and reduces the rate of collisions.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-21T12:34:22Z
      DOI: 10.1177/09544070231186841
       
  • Research and optimization of valve curve parameters for homogeneous charge
           compression ignition based on variable valve actuation

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      Authors: Yaodong Wang, Xinmei Yuan, Yan Su, Fangxi Xie, Jincheng Li, Yanfeng Gong
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Homogeneous charge compression ignition (HCCI) can improve engine emissions and fuel consumption. HCCI based on variable valve actuation (VVA) benefits from the wide application of VVA technology, which makes it easier to popularize. However, most VVA mechanisms are based on cam drive and inherit from spark ignition (SI) engine, the valve lift and duration can only be increased or decreased simultaneously. Therefore, the above VVA mechanisms cannot give full play to the performance of HCCI. The control parameters of valve curve are simplified into maximum valve lift and duration. At different speeds, this paper uses GT-POWER to first study the influence of the matching relationship between maximum valve lift and valve duration on HCCI combustion economy, and then study the design strategies of HCCI valve curve with fuel economy as the target. At same speed, multiple valve curves can achieve almost the same load range, however, among those valve curves, under the condition that the pumping loss and temperature in the cylinder are almost identical, the valve curve with lower cylinder volumetric efficiency can achieve lower indicated specific fuel consumption (ISFC). For low and medium loads, there is a better matching relationship of valve curve for each speed. For high loads, large maximum valve lift combines with large valve duration is easy to obtain lower ISFC in most situations, but the ISFC deteriorates significantly for low and medium loads. The fixed valve curve can obtain a smaller IMEP range or a higher ISFC; the optimized valve parameters combine with SI valve control strategy and VVT of 110°CA can only optimize the load range of partial speeds, the load range of other speeds will attenuation and the ISFC is higher; the newly designed valve curve scheme in this paper can achieve the maximum IMEP range and relatively low ISFC.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-21T12:31:04Z
      DOI: 10.1177/09544070231186832
       
  • Converting post-crash deformation into energy equivalent speed (EES):
           Toward an objective measure of crash severity

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      Authors: Pascal Breitlauch, Mirko Junge, Christian Erbsmehl, Volker Sandner, Michiel van Ratingen
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In this paper, an objective method for the conversion of post-crash vehicle deformation to crash energy is presented. While the crash severity assessment for standard crash test configurations is relatively robust, bias in real-world crash reconstruction is a well-known problem. A method to reduce the bias in crash severity reconstruction is constructed by focusing on post-crash deformation, the principle direction of force (PDOF), and vehicle type (VT) only. The analysis was restricted to 12 PDOF and six VT. A voxel model, onto which the depth information of the post-crash deformations was mapped, was constructed for every PDOF and VT. Standardized crash tests were used to normalize the deformation energy assigned to each voxel. The plastic deformation energy was computed by integrating this energy across all deformed voxels. This energy is expressed as the “energy equivalent speed” (EES). The method allows for a retrospective calculation of the EES from deformations. Thus, objective EES values can be computed for crash databases like CISS or GIDAS and even for legacy databases like NASSCDS. The results from the EES model will become part of the standard GIDAS database. The EES model was tested using a car-to-car crash test, a 40% offset frontal-frontal collision of an Audi Q7 against a Fiat 500.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-18T12:29:02Z
      DOI: 10.1177/09544070231186842
       
  • Multi-source motion constrained model predictive control for
           tractor-trailer trucks with coupled dynamics

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      Authors: Chen Xu, Ming Yue, Jinyong Shangguan, Mingyang Xu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      This paper proposes a constrained model predictive control (MPC) for tractor-trailer trucks with the complicated physical characteristics, where motion constraints can be considered to govern the vehicle maneuver. Firstly, a targeted theoretical derivation method is developed to establish a more accurate nonlinear model for articulated vehicles, with expressly considering the articulation coupling effects. As an essential basis, the kinematic coupling behavior is further investigated. Secondly, multi-source motion constraints are introduced in particular with the analysis of nonholonomic constraints on the underactuated trailer: (i) keeping trucks traveling in the feasible domain away from collision; (ii) maintaining the vehicle states in a stable field through the steady-state response and side-slip thresholds. Thirdly, a constrained MPC controller is constructed for the automatic tracking operation, wherein vehicle demands of position security and yaw stability will be taken into reasonable consideration. For this purpose, vehicle states information can be fully utilized in a parallel approach to optimize quadratic programming (QP) in MPC: model prediction and updated constraints. In the end, the contrasted-simulation analysis is carried out to verify the accuracy of derived model and effectiveness of the designed controller, along with the feasibility of the additive multi-source constraints.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-13T05:15:23Z
      DOI: 10.1177/09544070231185803
       
  • Proposing a chemical kinetic mechanism for biodiesel/NG blend in RCCI
           engine condition

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      Authors: Emad Aminian, Ayat Gharehghani, Mostafa Mirsalim
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Abundance of natural gas (NG), its clean combustion characteristics and relatively low cost among various fuels, make it a suitable alternative for gasoline. In use of NG instead of gasoline especially in RCCI engines, due to lower cetane number of NG, using diesel similar fuel with higher cetane number, such as biodiesel, is recommended. Numerical study of biodiesel-NG oxidation needs to have a special chemical kinetic mechanism which predicts characteristics of combustion and emission accurately. There is no compact, accurate and reliable chemical mechanism which predict combustion specification of biodiesel-natural gas blend for using in CFD simulations, especially in RCCI engine conditions. For this purpose, a compact skeletal Methyl decanoate (MD), Methyl-5-Decanoate (MD5D), n-decane, and NG mechanism including 66 species and 229 reactions is constructed in this work for biodiesel-natural gas CFD simulations. The GRI-mech3.0 NG mechanism, consist of 53 species and 325 reactions, is reduced first by DRGEP and FSSA methods in Chemkin Pro 0-Dimensional homogeneous reactor, and then the reduced mechanism containing H2/CO/C1-C3 is merged with the biodiesel sub-mechanisms of MD, MD5D, and n-decane which consist of 60 species and 172 reactions. In following, the coupled mechanism is optimized by reaction rate adjustment and reduced with QSSA method. Ignition delay and flame speed are validated with primary mechanisms results and experimental data. Comparing ignition delay times of based and developed mechanisms revealed that arithmetical mean error (AME) is 1.2% for 0%-NG and 6.34% for 0%-biodiesel, respectively. In 1-D simulation, flame speed is calculated and the AME for 0%-biodiesel and 0%-NG is 7.2% and 4.7%, respectively. To ensure the applicability and accuracy of the developed mechanism, this mechanism was used in the CFD simulation of an RCCI engine and the obtained results such as in-cylinder pressure and the heat release rate, were in appropriate agreement with the experimental results.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-10T09:30:55Z
      DOI: 10.1177/09544070231186278
       
  • DQN regenerative braking control strategy based on adaptive weight
           coefficients

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      Authors: Yanli Yin, Xinxin Zhang, Sen Zhan, Shenpeng Ma, Xuejiang Huang, Fuzhen Wang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Aiming at the problems existing in regenerative braking control strategy based on Q-learning which include the dimensional disaster of state and action variables discretization and the return function weight coefficient determined empirically. This paper proposes deep Q-learning network (DQN) regenerative braking control strategy based on adaptive weight coefficients. Firstly, braking performance evaluation indexes are determined which are braking energy recovery efficiency and braking stability coefficient. Then, the state and action variables and return function are constructed respectively. Therein the braking demand power and state of charge (SOC) are taken as state variables, braking torque proportional coefficient, and weight coefficients are taken as action variables. And return function is formulated by trading off braking energy recovery efficiency and braking stability. Finally, using the MATLAB/Simulink software, the simulation model of real working condition in Yubei district of Chongqing is established. The simulation results show that braking recovery efficiency of the proposed strategy is 7.4% higher than that of Q-learning strategy, and the average braking stability coefficient is decreased by 0.08. The results indicate the proposed strategy can better balance between braking energy recovery efficiency and braking stability than the conventional strategy.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-10T09:25:02Z
      DOI: 10.1177/09544070231186200
       
  • Analysis and optimization of tip-out transient dynamic characteristics of
           electric vehicle reducer under multi-bearing collaborative preloading

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      Authors: Dong Guo, Yufa Zhou, Mingmao Hu, Ming Li, Yingxue Li, Zhigang Zhang, Wenyi Rao
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In this study, the transient dynamic response of an electric vehicle secondary reducer with a multi-bearing cooperative preload was studied. The time-varying mesh stiffness, mesh damping, backlash, axial dynamic stiffness, and axial preload of the system are considered. A novel transient dynamics model was established for the multi-bearing cooperative preloading of the electric vehicle secondary reducer suitable for transient conditions. The accuracy of the built model is verified using a bench test. Subsequently, the transient dynamic response of the reducer system under tip-out working conditions was determined. The optimal preload combination of the bearing was determined using an optimization algorithm. The simulation results show that, under the tip out working condition, increasing the bearing preload can effectively restrain the transient impact of the reducer system, and the optimal bearing preload combination obtained by multi-objective optimization using an optimization algorithm can significantly reduce the transient shock problem of the electric vehicle drivetrain. This study provides theoretical support for suppressing transient shocks in electric vehicle reducer.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-10T09:18:28Z
      DOI: 10.1177/09544070231186193
       
  • An improved equivalent magnetic network model of IPM motor in electric
           vehicles for dynamic simulation of transient effects

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      Authors: Shuaishuai Ge, Yaoze Yang, Zhigang Zhang, Dong Guo, Honghai Ren
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The existing electric motor model for electric vehicles cannot address the simulation of transient conditions. Moreover, it is difficult to balance the computation time and simulation accuracy. To address these shortcomings, an improved internal permanent magnet motor model containing nonlinear magnetic field factors was proposed based on the equivalent magnetic circuit theory. The effects of the magnetic circuit saturation, cogging torque, and magnetic field harmonics on the electromagnetic torque could be reflected. Furthermore, the electromagnetic vibration and rotor eccentricity could be considered. To improve the computational efficiency of the equivalent magnetic network method, lumped parameter or mesh-based methods were used for flux paths with different complexities. Second, the single-layer mesh-based method with local variable permeability parameters improved the efficiency of the air-gap dynamic analysis and computational efficiency while simulating 2D flux paths. The radial and tangential electromagnetic forces were calculated using the Maxwell tensor method and the action on the rotor. The accuracy of the nonlinear magnetic field modeling was verified by finite element analysis and experimental. In addition, the motion modeling method and dynamic characteristics of the model were studied. A reference was provided for dynamic simulations of electric vehicles and other using permanent magnet motors.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-10T09:13:08Z
      DOI: 10.1177/09544070231186192
       
  • Establishment of a two-axis commercial vehicle 6DOF prediction model for
           nonlinear MPC controller

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      Authors: Boshi Zhang, Shuming Shi, Shuyou Yu, Jianhua Yu, YongFu Li, Fanyu Meng, Nan Lin
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Most of the commercial vehicle dynamics models used by nonlinear MPC controllers are 3-DOF models, which do not reflect the motion constraints of sprung and unsprung masses, the coupling relationship between translational and rotational motion, and the coupling characteristics of lateral and longitudinal tire forces, so it is difficult to meet the model prediction requirements under extreme working conditions. Therefore, according to the dynamics theory, this paper firstly establishes a 14DOF model which can reflect the movement characteristics of the sprung mass in the lateral, longitudinal, and vertical space, the suspension characteristics and the movement characteristics of the wheels on both sides. Then, in order to reduce the computational burden of the model prediction and make it applicable to the nonlinear MPC controller, the 14DOF model is simplified to the 6DOF model. Finally, the established 6DOF model and the classical 3DOF commercial vehicle model were compared and evaluated based on the error in prediction horizon and performance in trajectory tracking. The results show that the model that, in extreme working conditions, the new 6DOF model has obvious accuracy advantages compared with the classical 3DOF model in the prediction horizon, and can achieve convergence to the reference states faster, so as to obtain a solution efficiency similar to or even higher than 3DOF.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-10T09:06:30Z
      DOI: 10.1177/09544070231182181
       
  • Negative dynamics effect of in-wheel switched reluctance motor with
           inclined airgap eccentricity on handing stability for electric vehicle

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      Authors: Xu Li, Zhaoxue Deng, Tao Chen, Yangrui Zhang, Hanbing Wei
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      This paper focuses on the negative effect of in-wheel switched reluctance motor (SRM) with inclined airgap eccentricity for the handling stability of electric vehicle (EV). Firstly, the radial electromagnetic force of the SRM under inclined airgap eccentricity is deduced based on the Maxwell stress tensor and airgap permeability correction coefficient, and the calculation results are verified by the built measurement device. Then, a dynamics model of in-wheel motor driving EV is constructed according to the response relationship of driving wheels. Finally, the influence of unbalanced radial torque (URT) on the negative dynamic effect of EV is analyzed with angular step input and sine input respectively. The simulation results show that the EV will deviate from the expected trajectory due to the impact of URT, which will threaten driving safety in vehicle steering or overtaking. In addition, the vehicle yaw velocity will deteriorate with the increase of the driving speed and turning angle, which will affect the dynamics response of vehicle handling stability. This research, starting from the coupling relationship between in-wheel motor response characteristics and vehicle driving conditions, can provide theoretical support for the popularization and application for in-wheel motor driving EVs.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-07T12:36:50Z
      DOI: 10.1177/09544070231186198
       
  • Real-time vehicular fuel consumption estimation using machine learning and
           on-board diagnostics data

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      Authors: Hamidreza Abediasl, Amir Ansari, Vahid Hosseini, Charles Robert Koch, Mahdi Shahbakhti
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Instantaneous fuel consumption estimation of fleet vehicles provides essential tools for fleet operation optimization and intelligent fleet management. This study aims to develop practical and accurate models to estimate instantaneous fuel consumption based on on-board diagnostics (OBD) data. Fuel consumption data is measured by a high-precision fuel flow meter. Two machine learning algorithms of Random Forest (RF) and Artificial Neural Networks (ANN) are trained with real-world urban and highway driving data of four fleet vehicles with different types and powertrain systems. In addition, the cold-start period of the vehicle operation is included to cover the fuel consumption penalty in the warm-up period. The validation results show that the RF method is more accurate than the ANN method, and both of the machine learning models have a better accuracy compared to the existing fuel consumption calculation methods based on the engine control unit (ECU) parameters.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-06T11:49:47Z
      DOI: 10.1177/09544070231185609
       
  • Effect of ventilation on airflow pattern and thermal environment inside
           tractor cabin in summer: A case study of numerical simulation

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      Authors: Xiuning Hou, Xuemin Zhang, Yuancong Gong
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      As the tractor plays a more and more important role in agricultural operation, it is very important and meaningful to study the thermal environment in its cabin to improve the thermal comfort of the operator. In this study, the heat transfer model in the tractor cabin is established by using computational fluid dynamics (CFD), and the effectiveness of the numerical model is verified by field measurement. The distribution of airflow, temperature and the equilibrium temperature of cabin under different ventilation conditions are deeply discussed. The thermal comfort of driver was evaluated by predicted mean vote (PMV), predicted percentage of dissatisfied (PPD) and asymmetry coefficient. The simulation results show that the cooling effect and speed of the cabin are more stable by reducing the air supply temperature, and in a certain range of low air supply speed, increasing the air supply speed is more effective for cabin cooling. Considering the cooling rate, cooling effect and human thermal comfort, the combination of air supply temperature of 16°C, air supply speed of 1.0 m s−1 and vertical guide vane angle of 60° can be considered as the appropriate conditions for summer cooling. Additionally, on the basis of the same energy consumption, thermal comfort can be improved by increasing the air supply speed for refrigeration. This study provides a theoretical basis for the adjustment of the ventilation condition from different perspectives such as the cooling effect and human thermal comfort.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-06T11:41:15Z
      DOI: 10.1177/09544070231185189
       
  • Adaptive authority dynamic game for human-machine cooperative control

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      Authors: Shaosong Li, Han Wang, Detao Li, Xuyang Wang, Xiaohui Lu, Zhixin Yu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      An adaptive dynamic allocation strategy for driving authority based on the non-cooperative game was designed to solve the decision conflict problem between the driver and automatic system in human-machine driving. The coupling dynamics model of human-machine interaction was established according to the coupling mechanism between the driver and the automatic system. Considering the driver’s driving status and the driving risk of vehicles, the driving authority dynamic allocation strategy was designed. On this basis, the human-machine cooperative multi-objective optimal control problem is constructed, and the dynamic allocation control system was designed based on the non-cooperative game theory. The optimal control method was used to solve the Nash equilibrium solution and achieve the optimal authority allocation. The effectiveness of the proposed adaptive authority dynamic allocation strategy was verified under normal and emergency conditions. Results showed that the proposed strategy can effectively reduce human-machine decision conflicts and achieve harmonious human–machine cooperative driving.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-06T11:31:43Z
      DOI: 10.1177/09544070231182458
       
  • Multisource fusion of exogenous inputs based NARXs neural network for
           vehicle speed prediction between urban road intersections

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      Authors: Yunshun Zhang, Minglei Gao, Guodong Hua, Qishuai Xie, Yuchen Guo, Rencheng Zheng
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The economy and safety of passages through the urban road intersection environment is an important research topic in the field of intelligent transportation systems, but vehicle speed prediction as its subtopic is still under-researched, and its prediction accuracy is unsatisfactory. Therefore, a model for vehicle speed prediction based on the nonlinear autoregressive model with multisource exogenous inputs (NARXs) neural network is proposed. The model combines the human-vehicle-road model with the NARXs neural network to perform speed prediction between urban road intersections. First, multisource features, including the variables of driving behavior characteristics, vehicle responses, and road conditions, are extracted to construct the human-vehicle-road model. Then, the model is introduced into the NARXs neural network. Finally, the advantages of the proposed model are verified from two perspectives by evaluation indices such as mean absolute error (MAE), mean absolute percentage error (MAPE), root mean square error (RMSE), Theil index (Theil ic), and goodness-of-fit (R2) compared with several other models. On the one hand, the analysis results show that the proposed model has higher prediction accuracy than the other comparative models for different prediction durations and has the best performance in 30 s duration backward prediction. On the other hand, the curves of each evaluation index of the proposed model are horizontal, which indicates that the prediction performance of the model hardly varies with the length of the training dataset. These positive results demonstrate the higher accuracy and outstanding characteristics of the proposed model in the subject of vehicle speed prediction.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-06T07:12:53Z
      DOI: 10.1177/09544070231186186
       
  • Brake-by-wire architecture design and analysis in accordance with
           functional safety standard

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      Authors: Yanfeng Fang, Weida Wang, Chao Yang, Yuhang Zhang, Zhentao Chen
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The brake-by-wire (BBW) system is one of the safety-critical components of intelligent vehicle chassis, and ensuring its reliability requires a comprehensive functional safety design process. Although many studies have been conducted on electro-mechanical braking (EMB), there is a lack of relevant content on electro-hydraulic braking (EHB), another scheme of BBW system. And the key components affecting EHB system reliability need to be further explored. To address these issues, a system-architecture for EHB with fail-operational capabilities based on ISO 26262 is proposed. Additionally, Fault tree analysis (FTA) and Bayesian network (BN) are used for assessing its reliability. Fault tree (FT) is established to quantitatively calculate the Automotive Safety Integration Level (ASIL). Then FT is mapped into BN, and the conditional probability table is modified to express the polymorphic and uncertain logical relationship of events. To mitigate the dimensional disaster caused by numerous risk factors in the joint probability distribution, a Noisy-or gate method is applied in the BN to address this problem. Finally, the crucial events of system reliability are analyzed. The results indicate that the proposed EHB architecture can meet the safety and reliability requirements of ASIL D and can provide essential reference for the design of EHB related fail-operational system.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-07-01T07:22:31Z
      DOI: 10.1177/09544070231185192
       
  • Billion-design-variable-scale topology optimization of vehicle frame
           structure in multiple-load case

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      Authors: Yuji Wada, Tokimasa Shimada, Koji Nishiguchi, Shigenobu Okazawa, Makoto Tsubokura
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In topology optimization, sufficient resolution and a constraint volume of less than 1% are required to obtain a practical vehicle body structure without solid circular-section frames. To meet the requirement for sufficient resolution, the authors are developing voxel topology optimization software, including a finite element solver that utilizes the building cube method framework available in massively parallel environments. The authors have performed a topology optimization of billions of elements intended for a vehicle frame using 35,000–66,000 processors and measured its parallel performance. In addition, four different methods to treat multiple-load cases required for vehicle performance into single objective functions are examined. As a result, normalizing compliance with the appropriate target energy obtained by the original body-in-white frame balances the optimization performance across cases. In the single-load case, thick solid beams are generated through optimization. In contrast, such solid frames are suppressed in multiple-load cases, resulting in a structure similar to a practical body-in-white frame.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-30T12:49:44Z
      DOI: 10.1177/09544070231184309
       
  • Distribution of benzene and formaldehyde in tractor cabin: Effects of
           components, ventilation conditions, and vent positions

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      Authors: Xiuning Hou, Xuemin Zhang, Yulong Wang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Tractor cabin is a relatively closed microenvironment in which operator is exposed to various pollutants that can adversely affect human health. In this study, the distribution of benzene and formaldehyde inside tractor cabin was investigated using computational fluid dynamics (CFD) method and verifying its effectiveness with field measurements. The effects of pollution source, ventilation, and vent position on the distribution of pollutants were discussed by using the validated CFD model. The results indicated that the areas with high concentration of pollutants are mostly distributed in the corners, and the ceiling contributes the most to its emission. The concentration difference of benzene and formaldehyde in the driver’s breathing area can reach a maximum of 20% by adjusting the air supply angle. It can also be reduced by 3.9% and 4.3% for every 1 m s−1 increase in air supply speed when the airflow angle emitted from the vent was 90°. In the common vent locations, the vent arranged on the front ceiling has the best pollutant reduction effect. This study provided a reliable CFD simulation method for benzene and formaldehyde distribution, offered a theoretical basis for the selection of ventilation conditions and the design of internal layout in tractor cabins for improving air quality. It also suggested that then environment and air quality of non-road mobile machinery cabs should be paid more attention in the future.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-30T12:43:32Z
      DOI: 10.1177/09544070231184102
       
  • Research on economical mode switching control strategy of dual-motor
           

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      Authors: Kaibin Cao, Minghui Hu, Wanhong Li, Long Chen, Guanlong Yang, Jun Zhai, Chunyun Fu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In existing research on economical-performance control strategies for 4WD EV, only vehicle control strategies obtained through static efficiency interpolation of the electric-drive-system are considered, without considering the influence of high-frequency mode switching on energy consumption, and the difference between the actual power loss of the motor step-torque transient response and the theoretical loss calculated by steady-state map interpolation in the mode switching process. The research presents an economical mode switching control strategy that considers the step-torque transient response power loss caused by motor drag and mode switching. An electric-drive-system torque response testing platform was built to study the influence of the actual power loss of the motor step-torque transient response on energy consumption during mode switching under transient conditions. A mode boundary division method was proposed to analyze how different mode division impact on energy consumption and mode switching frequency so as to find the relationship between different operating points and mode boundary areas, and the optimal mode boundary width in each characteristic range was optimized hierarchically to realize reduction in energy consumption by 3.37% and reduction in mode switching frequency by 63.13%. Among them, the optimal mode boundary width accounts for 83.33% of the vehicle energy consumption reduction rate.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-30T12:35:52Z
      DOI: 10.1177/09544070231182739
       
  • A cooperative car-following control model combining deep optical flow
           estimation and deep reinforcement learning for hybrid electric vehicles

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      Authors: Jianhao Zhou, Jiaqing Chang, Aijun Guo, Wanzhong Zhao, Jie Wang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Deep reinforcement learning (DRL) based car-following control (CFC) models are widely applied in the longitudinal motion control tasks of automated vehicles by self-learning for the optimal control policy. However, DRL algorithms easily produce unsafe commands and have low robustness, especially in complex car-following scenarios. To improve the DRL-based CFC model, this paper combines the deep deterministic policy gradient (DDPG) based CFC model with the deep optical flow estimation (DOFE) based CFC model that can overcome the shortcomings of DDPG-based one which is denoted as cooperative car-following model (DDPGoF). The DDPG-based CFC model utilizes prioritized experience replay which can intrinsically accelerate the learning speed. Meanwhile, the proposed DOFE-based CFC model employs the recurrent all-pairs field transforms algorithm (RAFT) and EfficientNet to perceive the motion variation of the surrounding vehicles, motorcycles, etc. The real vehicle driving data sets are applied to calibrate and validate the proposed DDPGoF-based CFC model while several assessment criteria are established to evaluate its overall performance. As a result, the DDPGoF-based CFC model is superior to DDPG-based one in avoiding crashes, improving car-following stability, riding comfort, and fuel economy of HEV.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-30T12:25:50Z
      DOI: 10.1177/09544070231181667
       
  • Vehicle velocity estimation based on WSS/IMU with wheel slip recognition

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      Authors: Liangxin Yuan, Hao Chen, Yuan Wang, Xiaomin Lian
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Accurate velocity is of great significance to vehicle dynamic control, and vehicle velocity estimation based on wheel speed sensor (WSS) and inertial measurement unit (IMU) is more cost-effective than other sensors. Unavoidable wheel slip will result in velocity vector estimation error. To solve this problem, this paper proposed a novel wheel slip recognition criterion when using WSS/IMU for velocity estimation. The basic idea is to deduce the strict relationship between wheel speed, angular rate, and specific force when the wheel does not slip, and the slipping wheel will destroy this balance, which can be used to determine whether the wheel is slipping. Wheels identified as slipping are isolated from fusion, and only non-slipping wheels can be used for velocity estimation. In addition, the analysis shows that the wheel slip recognition is robust and works well even if there is an estimation error in the lateral velocity during vehicle turning. The co-simulation based on Carsim-Simulink shows that the proposed wheel slip recognition can ensure accurate vehicle velocity estimation at various working conditions. The real vehicle test further verified the important role of wheel slip recognition for velocity estimation.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-30T12:16:53Z
      DOI: 10.1177/09544070231181163
       
  • Lane-changing control for hybrid electric vehicles with dedicated hybrid
           transmission based on robust model predictive control

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      Authors: RuoChen Wang, LingJie Shen, YaZhou Zhou, RenKai Ding, Qing Ye
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Car-following and lane-changing are extremely important for vehicles. The traditional adaptive cruise control (ACC) strategy has various drawbacks due to the complicated driving conditions. A new control strategy of robust model predictive control (RMPC) for car-following and lane-changing is proposed based on a new type of hybrid electric vehicle (HEV) with dedicated hybrid transmission (DHT-HEV). The control model includes a vehicle model, a following and lane-changing model and an RMPC controller. The vehicle model integrates the DHT-HEV and dynamic models with a longitudinal dynamic model, seven degrees of freedom (DOF) vehicle dynamic model and three DOF control model. The following and lane-changing model is described as car-following and lane-changing models of two-quintic function. The RMPC controller is used to balance the control of vehicle longitudinal and lateral dynamics with the lateral acceleration disturbance. Simulation results demonstrate that the RMPC controller can track the reference trajectory during two lane-changing process when the test scenarios of different accelerations are set compared with the conventional ACC control. Different Np (predictive horizon) and Nc (control horizon) are also analysed to improve the solving performance of RMPC. Results indicate that the solving performance of the system is optimal when Np = 30 and Nc = 1. Furthermore, different weight coefficient matrixes (Q and R) are taken into the consideration by coordinating the car-following performance and lateral stability. Accordingly, the controllers of RMPC-LC, RMPC-ACC and RMPC-LA are set, demonstrating that the control of RMPC-LA best balances two aspects and is always within a safe car-following distance. Meanwhile, the hardware in the loop (HIL) is utilised to verify the effectiveness of the proposed RMPC control strategy, which comprises model compilation, the establishment connection between the D2P ECU and the simulator and control input.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-30T11:09:40Z
      DOI: 10.1177/09544070231181664
       
  • A safe and efficient decision algorithm for ramp merging based on a
           hierarchical planner and model predictive control

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      Authors: Hao Pan, Bin Xiao, Linhui Chen, Daofei Li
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Due to highly dynamic interactions between vehicles, ramp merging decision is extraordinarily challenging in dense traffic. To deal with the non-convexity and inter-coupling of the decision-making problem, a top-level behavioural planner is proposed, which considers both the overall traffic situation and the individual characteristics of other interacting drivers. To ensure the implementability and efficiency of planning, a bottom-level motion planner is further designed with the guide of the top-level behavioural planner. The validation simulation using a naturalistic driving dataset shows that the proposed planning algorithm can achieve a success rate of 97.65% and has similar gap selection decision as human drivers. Then to track the planned vehicle motion, a nonlinear model predictive controller considering actuator delay and lag characteristics is proposed. Finally, the proposed planning and control modules are deployed in a turbocharged test vehicle, with satisfactory vehicle lateral and speed tracking errors, which validate the implementability of the proposed ramp merging decision algorithms.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-29T12:04:38Z
      DOI: 10.1177/09544070231182192
       
  • Role of the front wing/wheel setting-up on the optimal cornering
           performances of a Formula 1 car

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      Authors: Daniele Peri, Andrea Di Mascio
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      We propose a hybrid approach based on meta-modelling techniques and machine-learning algorithms to determine the best car configuration for each circuit. By a specific interpolation model, we obtain an accurate estimation of the car’s speed as a function of the front wing configuration and the bend curvature. Some high-fidelity fluid dynamic simulations train the model and extend it to the entire design space. These data are then used as input for a simplified car dynamics model, providing an accurate estimate of the ideal lap time. Comparison with actual telemetry data confirms that the resulting tool is reliable, fast and easy to use.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-29T09:05:57Z
      DOI: 10.1177/09544070231183757
       
  • Optimization and experimental analysis of a cost-effective
           magneto-rheological (MR) fluid for application in semiactive suspension of
           a passenger van

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      Authors: Mohibb e Hussain Jamadar, Pinjala Devikiran, Hemantha Kumar, Sharnappa Joladarashi
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The study presented in this article attempts to determine the optimal composition of iron particles in the MR fluid for vehicular application based on the size of the particles, the simulation response of a test vehicle model, and the cost of the fluid. The MRF samples with two different-sized particles in varying compositions are prepared and characterized on a rheometer. The performance of each MRF sample in the semiactive suspension of a test vehicle is determined by simulating its full car model on a random road. The response of the vehicle model during simulation, the size of the particles, the volume fraction of the particles in the carrier fluid, and the fluid’s calculated cost are input for the Response surface optimization technique. The optimization results revealed that the MR fluid with large-sized particles in a 25% volume fraction would be suitable for the said application. Moreover, it was found that the rheological performance of the optimized MR fluid was better than the commercial MR fluid. The performance of the optimized fluid in a MR damper was experimentally evaluated against the stock passive damper of the test vehicle. The results of the experiment on the test vehicle showed that the MR damper improved the test vehicle’s ride comfort by 36.58% over a speed bump and 11.3% on an off-road test track. The road handling was also improved by 45% over a speed bump and 46% over the test track.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-29T08:18:08Z
      DOI: 10.1177/09544070231184510
       
  • Research on interaction law of longitudinal/lateral slip of mountain
           tractor based on tire-soil model

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      Authors: Bing Han, Hao Dong, Xianxu Du, Zepeng Zhang, Zhen Li, Enrong Mao, Zhongxiang Zhu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      When the mountain tractor is along the slope contour operation, the driving wheel will cause a longitudinal or lateral slip due to complex driving conditions. In order to investigate the influence law between the longitudinal slip, lateral slip, and deflection slip, the parametrically modified wheel-soil model, dynamics model, and motion trajectory model were established, and the tractor lateral slope simulation model was built based on MATLAB/Simulink and CarSim software. The simulation results show that load traction has the most significant effect on the longitudinal slip rate, lateral slope variation has the most significant impact on the side-slip angle and lateral slip rate, and the lateral slope and load traction together affect the yaw angle and deflection slip rate. When the lateral slope is 15°, the tractor longitudinal speed of 3 and 6 km/h can maintain lateral stability of the longitudinal slip rate of 0.39 and 0.25, respectively. In order to verify the accuracy of the simulation model, the test platform was built. The results show that the average errors of the absolute values of left longitudinal slip rate, right longitudinal slip rate, yaw angle, and side-slip angle are 14.47%, 13.06%, 12.27%, and 11.04%, respectively. To sum up, the extreme driving conditions of the tractor will aggravate the longitudinal slip of the driving wheel, which in turn affects the lateral slip and deflection slip, and should be controlled to avoid tractor instability.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-29T08:16:47Z
      DOI: 10.1177/09544070231184506
       
  • Research on road tracking and anti-roll game control scheme of commercial
           vehicle based on Nash equilibrium

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      Authors: Haizhu Xu, Zhenguo Chen, Dexi Wu, Jiwei Feng, Guangfei Xu, Zhenzhe Ning
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In view of the problem that the active suspension conflicts with the road tracking system while resisting roll when the commercial vehicle encounters emergency road conditions in the process of unmanned driving, this article is based on the Nash non-cooperative open-loop feedback game theory, taking the road tracking system, and the active anti-roll system as the participants of the game. An interactive control scheme which can not only accurately steer but also take into account the vertical roll stability is proposed. Firstly, the coupled model of Horizontal pendulum-anti-roll for commercial vehicles is established and extended to the vehicle-road three-degree of freedom closed model. Then, based on the derivation of the linear quadratic optimal control model (LQ), the non-cooperative open-loop Nash game theory is used to obtain the interactive optimal control afferent the road tracking system and the active anti-roll system. Finally, the experimental scheme is verified by hardware in the loop experiment. The results show that the interactive control scheme of road tracking and anti-roll based on Nash non-cooperative game for commercial vehicles allows the vehicle to take the vertical stability into account while turning actively, thus ensuring the safety and stability of the vehicle during driving.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-27T12:04:52Z
      DOI: 10.1177/09544070231181657
       
  • Multi-axis and cornering stiffness properties of non-pneumatic wheels with
           symmetric helical honeycomb spokes

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      Authors: Zhou Zheng, Darshan Dorugade, Subhash Rakheja, Ramin Sedaghati
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Current non-pneumatic wheel (NPW) designs with non-helical honeycomb spokes generally show too high cornering stiffness and thereby rapid saturation of the cornering force, which may lead to inferior handling and directional control of the vehicle, particularly under high operating speeds. The design concept of NPWs with symmetric helical honeycomb spokes is thus proposed in this paper. Three-dimensional (3D) finite element (FE) models of a honeycomb NPW with symmetric helical spokes configurations of different cell and helix angles were developed in order to fundamentally study its multi-axis and cornering stiffness properties under a constant normal load. The validities of the developed NPW models with 0° helix angle and three different cell angles were demonstrated through comparisons of predicted wheel responses with results available in published studies. 3D simulations were conducted under two design constraints in terms of identical cell-wall thickness and identical load carrying capacity. The results suggest that increasing helix angle results in significantly greater in-plane shear stiffness of the honeycomb spokes and thus could effectively yield higher longitudinal and vertical stiffness of the NPW. An increase in helix angle also causes lower lateral stiffness for the wheel designs with 15.8° and 31.5° cell angles resulting from increases in the out-of-plane compliance of the spokes, apart from the notably lower cornering stiffness, particularly when it is increased to 30° and 45°. The cell-wall thickness, however, shows positive influences on multi-axis stiffness of the honeycomb wheel but negative effects on its cornering stiffness. The design concept of helical honeycomb spokes could offer better vehicle performances than the current designs in terms of braking/traction and handling characteristics. These are particularly important for promoting applications of the NPW in high-speed vehicles.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-26T06:01:42Z
      DOI: 10.1177/09544070231182769
       
  • Multi-mode switching control of electromagnetic hybrid suspension based on
           human subjective sensation

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      Authors: Jianan Xu, Farong Kou, Xinqian Zhang, Chen Chen
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      This study proposes a multi-mode switching control strategy based on electromagnetic hybrid suspension (EMHS) to achieve the best relationship possible between the vehicle’s vibration reduction performance and energy consumption. The working modes of EMHS are divided into active, semi-active, and energy recovery modes according to the relationship between the root mean square of weighted acceleration and the human subjective sensation. The two key switching parameters of the analysis sampling interval and switching judgment times are introduced to optimize the switching conditions and reduce the deterioration of comfort and handling stability caused by frequent system switching in mode switching decisions. In the sub-modes, it’s designed that an LQG main control loop uses an ant colony algorithm to optimize parameters to obtain the ideal output force. And inner-loop control strategies in active and semi-active modes are designed so that the actual force output by the actuator tracks the ideal force. The results show that the multi-mode switching control strategy can switch the EMHS reasonably in the three modes and achieve good vibration reduction performance. The RMS of SMA, SDD, and TDL are reduced by 27.5%, 6.3%, and 17.6%, respectively under the variable conditions road.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-26T05:58:00Z
      DOI: 10.1177/09544070231181931
       
  • Dynamic path-speed planning algorithm for autonomous driving on structured
           roads

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      Authors: Liu Fang, Zhao Xiaowen, Su Weixing, Wen Yonggang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Aiming at the problem of local path planning for structured roads, this paper proposes a framework of local path-speed planning for autonomous driving, which takes safety as the premise and improves driving efficiency. The framework simulates human driving thinking and divides the local path planning of autonomous driving into two parts: lane decision and path-speed planning. In the part of the lane decision, a lane decision algorithm based on driving risk field and safe distance is proposed, which can ensure driving efficient and ensure that the planning vehicle is always in a low-risk driving environment. In the part of the lane change path-speed planning, a candidate path generation algorithm based on uniform sampling of lane change time and a cost function considering lane change timeliness, driving safety, speed smoothness, and path continuity are proposed to achieve optimal path selection and speed planning. In the experiment part, there are six different driving tasks. In six scenes, the local path-speed planning framework proposed in this paper can plan a safe, efficient, and smooth driving path and a safe planning speed. Taking the scenario of detouring low-speed obstacles as an example, the path-speed planning algorithm proposed is compared with the path-speed planning algorithm based on discrete optimization in Hu et al. It has been verified that the algorithm proposed can ensure that planner is always at low environmental risks and drive with high driving efficiency.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-26T05:53:41Z
      DOI: 10.1177/09544070231181626
       
  • Parameters self-learning of solenoid valve for wheel pressure estimation

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      Authors: Lingtao Wei, Yicai Liu, Zheng Zhu, Xiangyu Wang, Liang Li
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      As the most important component of the braking pressure regulation circuit, apply valve directly affect the accuracy of pressure control and estimation, which in turn affects the performance of vehicle dynamics control. However, the not exactly same parameters in the manufacturing and the parameters change with wear and tear will introduce large errors in the model-based pressure estimation. In this paper, the electromagnetic model and hydraulic model of apply valve are proposed and illustrated, which is the basis for pressure estimation and air gap learning. The particle swarm optimization (PSO) is presented for the self-learning of apply valve air gap, and the pressure estimation algorithm is presented based on the learned air gap. The proposed model and the algorithm are verified in the vehicle test and Amesim simulation. The results show that the proposed algorithm achieves the estimation of air gap within the error of [math], and thus reduces pressure estimation error to smaller than [math].
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-19T06:27:02Z
      DOI: 10.1177/09544070231181844
       
  • On a numerical methodology to assess the fatigue life of connecting rods

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      Authors: Wentao Xu, Olivier Le Roux de Bretagne, Marzio Grasso, Matthew F Harrison, Owen Carless, Chris StLeger-Harris
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Although simulation-based fatigue analysis is a standard tool adopted in every sector including automotive industry, the design of engine components in automotive and motorsport applications mostly relies on simplified design approaches supported by time-consuming testing programs. This manuscript proposes a new methodology based on individual engine speed damage estimation and engine speed time history combined with Palmgren-Miner linear damage rule to predict the fatigue state of the connecting rod. The track data, engine multibody simulation (AVL ExciteTM) and engine combustion simulation (AVL BoostTM) are used to generate the initial variable trace that is processed to obtain the block programs. Stress amplitude estimated with finite element analysis (Abaqus) are used to estimate the damage from S-N curve and the cumulative damage is estimated with Palmgren-Miner cumulative damage model. The method proposed is demonstrated using a connecting rod case study and the duty cycle from the race on Sebring international raceway. This work shows the suitability of the approach and the benefit in terms of accuracy in the prediction of the fatigue life.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-19T06:24:24Z
      DOI: 10.1177/09544070231180996
       
  • Study on estimation method of soot loading under dynamic working state

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      Authors: Tao Qiu, Xuejian Ma, Yan Lei, Jun Fu, Xiulei Wang, Milan Cheng
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Accurately obtaining the soot loading in the Diesel particulate filter (DPF) is important for DPF, and current online real-time estimation methods only go up to about 2 g/L. In this paper, the DPF structure is simplified into a gas-capacity combined with gas-resistance, and the theoretical analysis of the simplified structure is carried out through the equivalent circuit analysis method. The time constant [math] corresponding to the DPF during the dynamic working state of the diesel engine is solved, and further analysis reveals that it is related to the incoming flow temperature T and the soot loading [math]. On this basis, a method for estimating the soot loading [math] based on the time constant [math] is proposed. Subsequently, experiments on engine load characteristics at different speed working states were carried out, and the dynamic process of DPF was analyzed at different soot loading [math]. It was found that the time constant [math] can be characterized by the difference in temperature stabilization time between the inlet and outlet; The smaller the incoming temperature T, the more significant the relationship between the soot loading [math] and the time constant [math]; The proposed estimation method allows for the identification of soot loading down to 1 g/L.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-16T09:38:57Z
      DOI: 10.1177/09544070231179859
       
  • An investigation of the effects of volute A/R distribution on radial
           turbine performance

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      Authors: Chao Li, Hua Chen, Yu Wang, Yi Wei, Guitao Wu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In order to meet the higher design requirements of radial turbines, it is necessary to clearly understand the impact of different design parameters on turbine performance. The A/R distribution is one of the most important design parameters for the radial turbine volute, but there are few studies on it. To clarify the effect of A/R distribution on turbine efficiency and blade excitation force, a detailed comparative study is carried out. An experimentally validated numerical method is used, and steady and unsteady CFD simulations are conducted in this study. The results show that the volute A/R distribution has a significant effect on the turbine efficiency, while a linear distribution can provide a more uniform inlet condition and thus improve the rotor efficiency. The flow parameters fluctuated significantly at the volute tongue. Although the efficiency is not sensitive to this fluctuation, it directly affects the excitation force on the rotor blades. The volute with S-shaped A/R distribution produces the smallest excitation force due to the smallest fluctuation. Two new A/R distributions are presented which combine the advantages of linear and S-shaped or convex A/R distributions with high efficiency and low excitation force. It is suggested that the A/R should be close to the linear distribution and decreases rapidly before the tongue.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-16T09:36:27Z
      DOI: 10.1177/09544070231180993
       
  • Development of adaptive cruising strategy of extended range electric
           vehicle based on driving behavior

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      Authors: Chao Ma, Jie Gao, Jianhui Chen, Kun Yang, Di Tan
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In order to develop an efficient and humanized adaptive cruise control (ACC) system for the extended range electric vehicle (EREV), a driving behavior based novel adaptive cruising strategy is developed using ACC system and EREV co-simulation model. The virtual driving platform is constructed and virtual driving experiments for various drivers are performed to obtain the core characteristics of different driver types. The constant time headway (CTH) safety distance model based on core characteristics and car-following model based on model predictive control (MPC) algorithm are developed to meet expectations of different driver types. An adaptive cruising strategy of ACC system in EREV is developed. Specially, the vehicle drive cost is investigated while the battery life and equivalent fuel consumption are considered. It is seen from the simulation results that the ACC system can meet the requirement of different driver types. Compared with the other three control strategies, the proposed adaptive cruising strategy can effectively reduce the vehicle drive cost.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-16T09:33:58Z
      DOI: 10.1177/09544070231179853
       
  • Fluid-solid coupling simulation study on fuel leakage and deformation
           characteristics of precision coupling component in common rail injector
           and influence of pressure equalizing structure

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      Authors: Yu-Hao Zhou, Guo-Xiu Li, Hong-Meng Li, Chun-Long Xu, Xiao-Jun Wu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In the foreseeable future, the use of fossil energy is still irreplaceable, makes efficient use of fossil energy and reduce emissions became important topics. Diesel engines have a very high share in the transportation field, and high-pressure common rail system has highly improved the performance of diesel engines. As the most important component of common rail system, the performance of common rail injector directly affects the engine. Precision coupling components are composed of moving parts with very precise clearance fit in the injector. With the wear of parts, fuel leakage of precision coupling components may reach the same level as injection quantity, which will seriously affect the injection pressure actually established, and then affect the power, efficiency, and emission performance of diesel engine. Many researchers have studied fuel leakage of precision coupling components, and put forward different methods to reduce fuel leakage, including improving the machining accuracy and machining annular grooves on parts. However, the wear of parts makes it a high-cost and low-effective method to improve machining accuracy. Besides, researchers have not fully considered the deformation of parts. In this work, fluid-solid coupling simulations were performed to analyze deformation and static fuel leakage characteristics, and to investigate effects of pressure equalizing structure on deformation and leakage of precision coupling component in common-rail injector. Different from the previous researches, the influence of machining the annular groove on the plunger sleeve instead of on the plunger, and influence of coexistence of annular groove and deformation were considered. The results show the deformation characteristics of the parts, the fuel flow characteristics in the gap, and the influence of the annular groove on the fuel leakage. The connection between the deformation of parts and fuel leakage, and potential methods to reduce the leakage are also discussed.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-14T06:56:23Z
      DOI: 10.1177/09544070231181161
       
  • Practical hybrid model predictive control for electric pneumatic braking
           system with on-off solenoid valves

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      Authors: Jinhai Zhao, Xiuheng Wu, Zhenghe Song, Liang Sun, Xiangyu Wang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Accurate and rapid braking pressure regulation in electric pneumatic braking systems (EPBS) is vital to vehicle safety. Due to the switching behaviors of the on-off solenoid valves, the operation of the EPBS shows a hybrid nature with both continuous variables and discrete events, which raises the hybrid control problem. One of the possible solutions is to employ the hybrid model predictive controller with the mixed logical dynamical (MLD) model based on the linear approximation of the system dynamics. However, the nonlinearity and complexity of the EPBS make the MLD model obtained by linearizing the system equations directly require high storage and computing capacity. To address these issues, this article presents a practical hybrid model predictive controller based on the system dynamics simplified expressions considering the EPBS pressure variations caused by on-off solenoid valve states at the current sampling time and the last sampling time. The relationship between the pressure variations and the on-off solenoid valve states is first studied by the system mathematical model, followed by applying the mixed logic dynamical modeling approach to establish the hybrid model of the pressure continuous dynamics with discrete features of on-off solenoid valves. Based on these, a hybrid model predictive controller is formulated to solve the EPBS pressure control problem. The simulations and bench experiments are carried out to verify the controller. Besides, an existing model predictive control (MPC) controller is compared with the proposed controller. All the results demonstrate the effectiveness of the hybrid model predictive controller.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-14T06:53:53Z
      DOI: 10.1177/09544070231180352
       
  • The influence of needle eccentric motion on injection and spray
           characteristics of a two-layered eight-hole diesel injector

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      Authors: Tianyu Jin, Chuqiao Wang, Adams Moro, Andreas Roell, Xiwen Wu, Fuqiang Luo
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      To meet the increasingly stringent emission regulations nowadays, the quality of injection and spray must be high. The eccentric displacement of an injector needle during injection influences fuel flow characteristics within the nozzle (in-nozzle) and the injection and spray characteristics from the nozzle holes. In this study, the effect of the needle (within a double-layered eight-hole nozzle) on in-nozzle flow, injection and spray was analyzed and characterized. The model was validated by comparing simulation and experimental results from each hole (hole-to-hole). The hole-to-hole internal flow characteristics, injection characteristics, and spray characteristics under various needle eccentricities and radial displacements (needle deflections) were also analyzed. From the results, different asymmetric fuel flow characteristics were noted. Nozzle holes close to the needle deflection formed spray jets with wider cone angles and shorter penetration whereas nozzle holes at the opposite side of the needle deflection, formed spray jets with relatively smaller cone angle and higher penetration. As the needle lift got closer to the maximum lift, the effect of the eccentricity on in-nozzle fuel flow decreased. The direction of the needle eccentricity (needle deflection) dictated the flow dynamics within the holes which then affected the type of cavitation. The holes closer to the needle developed string type cavitation due to the formation of vortex flow in the nozzle. The eccentric effect of the needle was felt more by the lower layer nozzle holes than the upper layer holes.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-14T06:48:38Z
      DOI: 10.1177/09544070231179779
       
  • Adaptive error injection for robustness verification of decision-making
           systems for autonomous vehicles

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      Authors: Xingyu Xing, Lihao Liu, Junyi Chen, Lu Xiong, Yanjun Huang, Zhuoping Yu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Robustness of the decision-making system is essential to safe driving, especially under the environment with inevitable defective information due to the limitations of the perception and positioning modules. The traditional fault-injection approach is widely used in robustness tests, but it mainly focuses on the endogenous fault instead of the exogenous errors of systems. In this paper, a robustness verification method based on error injection is proposed for the decision-making system against exogenous data errors. First, an error model is designed to generate potential data errors for different environment information. Then, an error injection framework with high versatility is proposed to support different decision-making systems and virtual test platforms. In addition, an optimization algorithm called LAMBDA is introduced to adaptively design experiments aiming to realize a quick search of safety-critical errors. Furthermore, an error injection tool is developed to conduct the verification test automatically. The proposed approach is verified on a city autopilot system under typical hazardous scenarios by the error injection tool, and the tolerance boundary of the system can be obtained as well. Compared to random-based and traditional optimization algorithms, the LAMBDA algorithm is able to quickly achieve a higher coverage for safety-critical errors. Although the approach is proposed for the decision-making module, it is can be easily extended to others, such as planning and control.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-10T10:07:23Z
      DOI: 10.1177/09544070231176934
       
  • Adaptive robust steering strategy for electro-hydraulic hybrid steering
           system based on backstepping method

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      Authors: Guobiao Shi, Minghao Song, Chengyun Ju, Shuai Wang, Pengfei Qiao
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Aiming at the angle tracking problem of electro-hydraulic hybrid steering (EHHS) system of heavy commercial vehicles in intelligent driving mode, the dynamic model of the system is established. In order to weaken the influence of nonlinear disturbance and parameters, an adaptive robust controller based on backstepping method is designed, a linear extended state observer is established to predict the disturbance. Triangular programming and trapezoidal programming are introduced into the upper level planning of steering angle position to improve the performance, so as to realize the tracking control of steering angle. In order to verify the effectiveness of the control algorithm, the designed controller is compared with DRC control. The results show that the controller used in this paper has higher servo accuracy, smaller error, and better robustness to interference. And to verify the improvement of the speed planning algorithm, the simulation is compared with the non-planning algorithm. The results show that adding the planning algorithm can reduce the control effect error and avoid the response oscillation to a certain extent. Finally, HIL bench test shows that the control strategies under various working conditions have good effect, and meet the steering angle tracking requirements of commercial vehicles in intelligent driving mode.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-10T08:35:24Z
      DOI: 10.1177/09544070231179073
       
  • Experimental verification of active damping of powertrain vibrations with
           simple fuzzy logic compensation for time-varying control period

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      Authors: Heisei Yonezawa, Ansei Yonezawa, Takashi Hatano, Shigeki Hiramatsu, Chiaki Nishidome, Itsuro Kajiwara
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      To ensure comfortability and lifetime of components, transient vibrations in a vehicle powertrain must be suppressed. This study proposes a novel active vibration control strategy with straightforward fuzzy inference compensation for time-fluctuations of control periods of engines used as actuators. First, a model prediction algorithm including a sampled-data controller (SDC) is applied for addressing the maximal phase lag of the control input caused by the fluctuated control period. Fluctuated renewal timings of the control input that are deviated from those of the periodical operated SDC are defined by fuzzy sets. These fuzzy sets are expressed as “Nearly past timing” and “Nearly future timing.” Using a human-intuition-like fuzzy compensation with only four inference rules, unknown control inputs at fluctuated update timings are reasonably determined from such fuzzy sets and periodical control signals given by the SDC. Experiments using an actual test device are performed to investigate the damping performance of the proposed control scheme. The experimental tests demonstrate that the novel active damping strategy significantly reduces transient vibrations despite the fluctuated control period. Moreover, several different test conditions newly reveal the robustness of the fuzzy compensation against fluctuations of variable regions in the control periods.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-02T10:06:41Z
      DOI: 10.1177/09544070231178103
       
  • Analysis of driving stability and smoothness based on magnetic negative
           stiffness suspension for cars

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      Authors: Dong Zhou, Huijie Zhang, Huirong Hao, Ziming Yang, Yanzhuang Cao
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Existing economy vehicles mostly use inexpensive passive suspensions, which struggle to fulfil the driving performance needs of people because of their fixed damping stiffness. This paper proposes to build magnetic suspensions by integrating inexpensive negative stiffness magnetic springs and passive suspensions to improve the suspension performance of such cars. Based on the constructed magnetic suspension model, simulations were conducted to investigate and analyse its stability and smoothness in various aspects. Finally, the performance was verified using experiments. The results demonstrate that adding magnetic springs in passive suspensions enables the total stiffness of the suspension to vary adaptively, enhancing the car’s driving stability. Furthermore, it also reduces the car body acceleration, the resonance interval of the suspension system and its displacement transmissibility, further improving the car’s ride smoothness. These performance benefits increase with increasing road excitation, and their role is more pronounced in off-road vehicles. This magnetic suspension system provides novel ideas for the further design of passive suspensions and lays the foundation for the future development of variable stiffness suspensions.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-02T10:04:21Z
      DOI: 10.1177/09544070231177339
       
  • A nonlinear disturbance observer based super twisting control for
           cooperative adaptive cruise control system affected by communication
           imperfections

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      Authors: Jaswandi Sawant, Uttam Chaskar
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      A cooperative adaptive cruise control system utilizes vehicle-to-vehicle communication in addition to onboard sensors. Vehicle-to-vehicle communication is established by a short-range wireless network, which is susceptible to communication delay or loss of communication frequently. It would result in higher inter-vehicle distance to maintain the string stability of a platoon. In this paper, a nonlinear observer-based super twisting control is proposed to retain the property of string stability in various practical scenarios of communication delay, complete loss of communication, and parametric uncertainty. It ensures asymptotic convergence of the spacing error. The stability of an individual vehicle and the string stability of a platoon is derived. The performance of the proposed scheme is compared with two well-known methods for controlling a platoon of cooperative adaptive cruise control and adaptive cruise control vehicles.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-06-02T10:00:52Z
      DOI: 10.1177/09544070231176590
       
  • Frequency-dependent automotive suspension damping systems: State of the
           art review

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      Authors: Bartłomiej Franczyk, Michał Maniowski, Janusz Gołdasz
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Configuration of a passive suspension of a passenger vehicle most often requires a compromise between its handling, road-holding, and ride (passenger) comfort. Nowadays, car manufacturers (automotive OEMs) are forced to develop ways for enhancing the functionality of shock absorbers and yet keeping their costs low. The use of so-called frequency-dependent (FD) valves in hydraulic passive suspension dampers, which allow the damping force to vary with the frequency of the excitation (or its change rate), is a satisfactory solution to the problem by means of adaptive passive valves. In this study, the effectiveness of the FD technology in passenger vehicles is demonstrated on the basis of a quarter-car simulation model. This is followed by a comprehensive review of several FD type valve structures currently offered by various automotive damper suppliers. Their advantages as well as potential drawbacks are shown and hydraulic circuits are formulated for each of the considered designs. Exemplary characteristics of a FD shock absorber obtained from own measurements are shown, too. The results of subjective qualitative evaluation of analyzed cases are presented and appropriate directions for further development steps are proposed. Finally, simulation results of functional model of FD shock absorber are presented.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-31T05:52:05Z
      DOI: 10.1177/09544070231174280
       
  • An adaptive finite-time control method for antilock braking system with
           experimental analysis

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      Authors: Youguo He, Yu Zhou, Xin Liu, Yingfeng Cai, Chaochun Yuan, Liwei Tian
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The antilock braking system (ABS) is a representative technology to improve the safety of hard braking in automobiles. The slip rate control has been a challenging issue due to the complicated characteristics of tires and the strong nonlinearity of the system. In this paper, a novel adaptive finite-time controller for ABS is developed to improve braking performance. Different from the current control strategies for ABS, the extended finite-time stability theory and state constraint are comprehensively considered in the proposed control strategy. The extended finite-time stability theory is applied to deal with the system uncertainties, by which the convergence of slip rate tracking error is achieved. And the asymmetric tan-type barrier Lyapunov function (BLF) is used to ensure that the wheel slip ratio is within a smaller and more stable area. Finally, according to the simulation and experiment, compared with the existing BLF controller, a faster convergence rate, better robustness and anti-disturbance performance of ABS can be achieved with the proposed strategy.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-31T05:51:22Z
      DOI: 10.1177/09544070231174656
       
  • Study on the influence of running parameters on the temperature field of
           disc brake on long downhill road

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      Authors: Wu Gang, Chen Tian, Liu ZhiPeng
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The braking system of the vehicle is liable to fail due to the high temperature of frequent braking in the downhill road. This paper analyzes the influence of the main operating parameters of the vehicle on the maximum temperature of the brake disc surface. Firstly, the mechanical characteristics of the vehicle on the long downhill road are analysed, and the Finite Element Model of the brake disc/friction plate is established; Secondly, the effects of gradient, vehicle weight, brake speed threshold and brake pressure on the braking cycle and disc brake temperature field on long downhill roads are studied. The results show that when the gradient increases from 3° to 9°, the maximum temperature of the brake disc increases by 41.6%, while when the vehicle weight increases from 4 to 7 tons, the brake disc temperature only increases by 16.7%. For the braking speed threshold and braking force that the driver can control, selecting a smaller braking force and a lower braking speed threshold can better inhibit the temperature rise of the brake disc. Finally, the effectiveness of the simulation method is verified by the real vehicle test. It is found that the average measured temperature is 9.2%–11.8% lower than the simulated average temperature. It is considered that the modified temperature value can be obtained by reducing the maximum temperature of the simulation model by 5%–6%.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-31T05:13:53Z
      DOI: 10.1177/09544070231177176
       
  • Lithium battery sorting method for high-rate operating conditions

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      Authors: Hanchi Hong, Hongze Li, Luigi d’Apolito, Yangqi Ye, Qianfan Xin
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Lithium batteries are increasingly used in electric vehicle applications. However, different manufacturing processes and technical constraints lead to battery inconsistency, even for batteries in the same production batch. High-rate discharging negatively affects battery consistency and results in service life reduction. A multi-parameter sorting method at high-rate operation was proposed in this study. The method was applied to sort batteries for cars. The sorted datasets were compared and analyzed by the fuzzy C-mean clustering method, the K-means clustering method, and the simulated annealing genetic algorithm. The comparisons proved that the genetic annealing algorithm was more suitable for battery classification. The clustered batteries were assembled into modules in series and parallel for experimental validation. The test results showed that the battery module cycle life was improved.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-31T05:07:57Z
      DOI: 10.1177/09544070231177177
       
  • Combustion performance characteristics of double-layer diverging
           combustion chamber compared with re-entrant chamber and omega chamber

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      Authors: Yao Fu, Xin Du, Xiaonan Ge, Jian Zhu, Han Xin, Shun Xu, Jie Yao, Wuqiang Long
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Combustion chamber is a main component for Diesel, as it organizes the fuel-air mixing and combustion processes and eventually determines Diesel performance. In the past decades, the chamber turned into the higher radius-to-depth ratio and lower area-to-volume ratio type to increase the in-cylinder air utilization and promote the fuel spray spreading. The Double-Layer Diverging Combustion chamber (DLDC chamber) was designed in this background. In order to obtain the DLDC chamber performance characteristics comprehensively, a 135-type Diesel with a DLDC chamber, a re-entrant chamber and a ω chamber was selected. The results suggested that the DLDC chamber decreased the BSFC and soot emission, but increased the NOx with higher pmax and heat release rates during the premixed combustion phase, as it could divide the fuel into two layers and promote the fuel spreading and combustion; adjusting the injection parameters made the BSFC and exhaust emissions of the DLDC chamber change quite differently, because the different layers of the DLDC chamber had their own chamber-spray-charge motion matchings. Finally, the investigation indicated that the DLDC chamber provided lower exhaust emissions compared with the other two chambers by keeping the same fuel consumption; moreover, the DLDC chamber provided the lowest BSFC and soot emission in the three chambers under the same NOx emissions level.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-29T10:46:16Z
      DOI: 10.1177/09544070231176692
       
  • Tire-road friction coefficient estimation for automatic guided vehicle
           under multiple road conditions

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      Authors: Wei Liu, Xiaowei Wang, Shuisheng Yu, Zhihao Xu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The traditional unscented Kalman filter (UKF) will have the problem of reduced accuracy or even divergence in the estimation process due to state model perturbation, unknown noise of the system, and other factors, which in turn affect the estimation results of the tire-road friction coefficient. By this problem, the paper investigates the tire-road friction coefficient estimation by taking an automatic guided vehicle (AGV) as the research object and proposes an adaptive singular value decomposition unscented Kalman filter (ASVD-UKF) with a noise estimator. Singular value decomposition (SVD) is introduced into the unscented Kalman filter (UKF) for Sigma sampling to suppress the negative definiteness of the state covariance matrix in UFK. The paper considered estimation schemes for joint road, μ-split road, and μ-different road and constructed corresponding ASVD-UKF observers to reduce the dimension of the road estimation model and real-time observation of four tire-road friction coefficients. Results show that the average absolute error of the μ-split road, joint road, and μ-different road proposed in this paper is significantly smaller than that of UFK, and the estimation accuracy is improved by 13.39%, 6.74%, and 5.71%, respectively. A Distributed Drive AGV prototype was developed for a real vehicle verification experiment, with only a 1.14% error between simulation and experiment. It is further proved that the designed observers are practical. The research can provide a theoretical basis and experimental foundation for the tire-road friction coefficient estimation.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-29T07:16:15Z
      DOI: 10.1177/09544070231177100
       
  • Effects of transfer case structural parameters on torque transmission
           based on thermoelastic instability

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      Authors: Yuming Wang, Liqing Chen, Hongliang Li, Jian Liu, Aiguo Zhao
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Based on the theory of thermoelastic instability, the thickness trend of lubricating oil film on the surface of the transfer case friction pair is studied, and the basic process is obtained in which the film thickness changes due to thermoelastic instability. Firstly, the dynamic simulation model of the transfer case is established, Secondly, since the thickness of the transfer case lubricating oil film is affected by the joint action of lubricating oil pressure, contact pressure and thermal expansion, this paper discusses the condition of thermoelastic instability of the transfer case torque transmission. The result shows that the critical speed of the thermoelastic instability increases correspondingly with the increase of the thickness of the oil film. The critical curve divides the engagement process into two parts, namely the stable region at the upper part of the curve and the unstable region at the lower part of the curve; then the thermoelastic instability region of the torque transfer of the transfer case is calculated. Next, in order to further analyze the influence of thermoelastic instability on the characteristics of the transfer case, three factors—the surface roughness of the friction plate, the lubricating oil viscosity, and the thermal conductivity of the dual steel disc—are mainly analyzed, which shows that thermoelastic instability does affect the critical speed and torque transmission of the transfer case. The conclusion is expected to be applied to the engineering practice of torque distribution control of the transfer case.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-29T07:06:51Z
      DOI: 10.1177/09544070231174941
       
  • Predicting pedestrian tracks around moving vehicles based on conditional
           variational transformer

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      Authors: Youguo He, Yongxin Yang, Yingfeng Cai, Chaochun Yuan, Jie Shen, Liwei Tian
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Fast and accurate prediction of pedestrian trajectory around vehicles can reduce or even prevent most traffic accidents and improve the safety of traffic participants. This involves the real-time interaction and fusion of various information, such as the vehicle’s motion characteristics, the pedestrian’s historical motion trajectory, and the motion relationship between people and cars. However, most of the existing algorithms use RNN as the skeleton to process the information prediction trajectory, which is weak in extracting the internal relationship between different information, and the running time of the algorithm is long. To solve these problems, we propose a Transformer based deep learning algorithm (CVTF) to complete the first-person perspective pedestrian trajectory prediction task. We have the following innovations about this model: 1: We use the stamp coding method for vehicle speed and pedestrian information to ensure we can learn the characteristics of different information sources. 2: Transformer structure is used, and its attention mechanism is improved (Maybe-self attention), which improves the running speed of the model and reduces the memory consumption. 3: Combined with Conditional Variational Autoencoder (CVAE), hidden variables are introduced to improve the prediction accuracy. Experiments on three pedestrian trajectory prediction benchmarks show that our model achieves the most advanced performance.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-27T04:24:26Z
      DOI: 10.1177/09544070231175536
       
  • BTAP dynamic model establishment and influence analysis of marine
           two-stage herringbone gear transmission system considering cracks

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      Authors: Dong Hao, Liu Zhen-bin, Hu Yan Xiao-rong, Yan Wen, Bi Yue, Zhao Xiao-long
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      To reveal the influence of cracks on the vibration characteristics of marine two-stage herringbone gear transmission system (TSHBGTS), a 48 degree of freedom bending-torsional-axial-pendular (BTAP) dynamic model of the system was established, which took into account the influence factors such as error, time-varying meshing stiffness (TVMS), torsional stiffness, support stiffness, tooth surface friction, and undercut. In the model, the TVMS of each gear pair in the Two-stage herringbone gear system with cracks was calculated by using the potential energy method, and the TVMS variation rule under different lengths, depths, and angle parameters of cracks was analyzed. The Runge-Kutta numerical integration method was used to solve the problem. The influence of different crack degrees on the vibration of each position of the TSHBGTS was analyzed. The influence of different crack degrees on the vibration response of was tested through tests. The difference in mechanical vibration between the normal gear and cracked gear was analyzed by using the frequency domain diagram and time domain diagram, and the influence mechanism of cracks on vibration characteristics was revealed. The results show that when the gear cracks, the TVMS of the gear decreases, and with the increase of the crack depth and length, the TVMS of the gear pair will gradually decrease. With the increase of crack depth and length, the TVMS of the gear pair is greatly reduced, and there is a periodic impact phenomenon in the time domain response of the system. With the continuous expansion of the crack, the impact phenomenon becomes more and more serious. In the frequency domain response, a modulated sideband centered on the meshing frequency appears. When the crack is generated and the crack degree increases, a small noise frequency is generated near the frequency doubling and increases with the growth of the crack. The correctness of the theoretical analysis model is verified through experiments, and the research results can provide a theoretical basis for the fault diagnosis of the herringbone gear transmission systems with cracks.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-26T10:24:06Z
      DOI: 10.1177/09544070231174651
       
  • Enhancing performance of permanent magnet motor for electric vehicle
           drives using model predictive control

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      Authors: Pramod Ubare, Vaishali Patne, Dayaram Sonawane
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In the electric three-wheeler vehicular segment, permanent magnet (PM) motors are strong competitors for traction applications. The vehicular environment faces sudden load variations, where traditional control like field-oriented control (FOC) over-excites the machine. It also degrades the machine’s overall performance due to dynamic changes in the motor states with limited bandwidth of the cascaded proportional-integral (PI) controllers; this makes the overall motor operation inefficient. The paper proposes a model predictive control (MPC) based on torque ripple and over-current excitation minimization for permanent magnet motors to overcome these challenges. The proposed controller is tailored to improve the overall electrical efficiency of permanent magnet motors while considering the real back EMF. The performance of the proposed controller is tested in simulation, considering an electric three-wheeler as a load along with a European driving cycle. The feasibility of the proposed method is tested by deployment on (1) STM32F546ZG micro-controller and (2) Xilinx’s ZYNQ-7000 SoC ZC706 FPGA and validated the implementation results with hardware-in-the-loop(HIL) co-simulation. The implementation results show that the proposed MPC outperforms the conventionally used FOC in energy consumption, torque ripples minimization, and torque disturbance handling while tracking the desired speed accurately with load variations.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-26T10:19:28Z
      DOI: 10.1177/09544070231169802
       
  • Adaptive robust control for reliable trajectory tracking of autonomous
           vehicle in uncertain driving environment

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      Authors: Ziwei Zhang, Ling Zheng, Yinong Li, Hao Zheng, Zhida Zhang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      External disturbances, parameter perturbance, data delay and control lag provoke significant model mismatches. If not properly compensated, they can greatly deteriorate the control performance of autonomous vehicle, such as reduction of tracking accuracy or even loss of stability in extreme. However, existing approaches barely consider these uncertainties together. In the light of this, an adaptive strategy is presented for trajectory tracking control of autonomous vehicle to simultaneously cope with aforementioned factors. First of all, given the dynamic or kinematic characteristics among path, vehicle and steering actuator, an integrated dynamic model is constructed. To handle the control lag of the steering actuator, a first-order model is utilized to approximate the dynamics of the steering subsystem, which is then integrated into the vehicle dynamics to reformulate the tracking model as a lag-free one. Then, the hierarchical robust tracking controller is proposed to acquire reliable control commands. To prevent the system breakdown in the presence of data delay, the delay-dependent criterion is designed via linear parameter varying technique and integral inequality approach. Moreover, the controllers also consider both the H∞ index and the guaranteed cost one to guarantee the effectiveness and robustness of tracking commands. Subsequently, to enhance the adaptability of algorithm, a feedback gains scheduling mechanism is proposed to adaptively tune tracking commands among different robust gains leveraging the phase plane approach. Finally, several comparative cases are conducted in the hardware-in-the-loop platform to verify that proposed strategy has better capability on trajectory tracking in uncertain driving conditions.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-17T09:58:55Z
      DOI: 10.1177/09544070231174652
       
  • Elman neural network-based temperature prediction and optimization for
           lithium-ion batteries

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      Authors: Chaoliang Li, Yuanlong Wang, Xiongjie Chen, Yi Yu, Guan Zhou, Chunyan Wang, Wanzhong Zhao
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Reliable and precise temperature prediction is one of the most crucial challenges for improving battery performance and preventing thermal runaway. This paper uses a highly adaptive Elman neural network (Elman-NN) to construct a temperature prediction model for lithium-ion batteries in a metal foam aluminum thermal management system. Numerical modeling methods obtain experimental data sets for model training and testing. The input parameters of the neural network prediction model are ambient temperature, battery discharge rate, cooling air flow rate, and state of charge; the output parameters are the maximum, minimum, and average battery temperature. However, due to the limitations of the gradient descent algorithm, the training process of the Elman neural network tends to fall into local optimum solutions. To further improve the prediction accuracy, the Elman-NN structure was optimized using the PSO algorithm, and the model performance was tested and validated. Compared with the original Elman-NN, the hybrid PSO-Elman-NN has smaller MSE and MAE values, with a maximum reduction of 43% and 25%, respectively. For the three test conditions, the maximum predicted temperature difference does not exceed 1.5 K, and the temperature difference decreases further as the discharge time increases. Moreover, the hybrid model’s prediction accuracy is significantly improved, with the coefficients of determination (R2) increasing by 1.736%, 0.706%, and 1.851%, respectively. The PSO-Elman-NN performed well in terms of compatibility and accuracy of the battery temperature prediction.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-17T09:47:07Z
      DOI: 10.1177/09544070231174118
       
  • Quantitative research on vehicle energy consumptions based on the
           longitudinal-vertical dynamics of the tracked vehicle

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      Authors: Zhiqiang Guo, Chunwang Liu, Junlin Luo
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In this paper, a longitudinal-vertical coupling tracked vehicle dynamic model is established to simultaneously describe the longitudinal, vertical and pitch dynamic responses of the tracked vehicle under off-road conditions. The road wheels are subjected to variable longitudinal-vertical forces due to the terrain unevenness and the excitations are transmitted to the vehicle body through the torsion suspension system. An experiment by means of a scaled-down tracked vehicle was carried out. The comparisons between the field test results and simulation results verified the effectiveness of the coupling dynamic model on predicting the vehicle dynamics. Taking advantage of the coupling tracked vehicle dynamic model, the energy computation formulas are further derived to quantitatively study the vehicle energy consumptions. The energy consumption distributions of the tracked vehicle on uneven road and paved road at different velocities are analysed. The computation results indicate that the developed energy computation method is reliable on predicting the energy generation and dissipation of the tracked vehicle. It has been found that the proportions of damping dissipation energy and road roughness caused energy consumption to total energy consumption are both higher at a greater speed.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-16T05:47:36Z
      DOI: 10.1177/09544070231174274
       
  • Optimization of aerodynamic drag reduction for vehicles with non-smooth
           surfaces and research on aerodynamic characteristics under crosswind

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      Authors: Wei Gao, Minxiang Wei, Shangzhu Huang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Energy consumption and environmental pollution problems have become increasingly prominent in China. The drag reduction of vehicles is an effective method to improve the fuel economy of cars and reduce greenhouse emissions. In this paper, based on the MIRA squareback model, the influence of the shapes, arrangements, layout positions, and dimensions of the non-smooth units on the aerodynamic characteristics of vehicles are investigated through the computational fluid dynamics (CFD) method. The depth, longitudinal spacing, and horizontal spacing are taken as the design variables and the aerodynamic drag coefficient is used as the optimization objective. The optimal Latin hypercube experimental design method is adopted to select sample points, and the response values of each experiment sample point are calculated through the integrated platform in Isight software. According to the response values, the Kriging approximation model is built and validated. Furthermore, the multi-island genetic algorithm is applied to optimize the dimensions of pit non-smooth units. The aerodynamic characteristics of the smooth surface model and the optimized non-smooth surface model under steady crosswind are conducted using numerical simulation. The findings obtained from the investigation will provide a certain reference for the application of non-smooth units in the field of automobiles.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-16T05:45:36Z
      DOI: 10.1177/09544070231173471
       
  • An air supply system regulation method for PEMFCs based on disturbance
           observation and MPC control

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      Authors: Dafeng Song, Qingtao Wu, Xiaohua Zeng, Xuanming Zhang, Dongpo Yang, Qifeng Qian
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The optimal tracking control of air pressure and air flow is an important guarantee to improve the output characteristics of fuel cells. However, under the load disturbances scenario, the optimal control effect is difficult to guarantee. In order to solve this problem, this paper proposes a new control method based on real-time disturbances observation and MPC optimal control. The decoupling of air pressure and air flow is realized by feedback linearization, and then an extended state observer is designed to achieve accurate estimation of load disturbances. Based on the principle of optimal output power of the fuel cell system, the reference trajectory of air pressure and air flow is obtained. Based on this, the optimal MPC controller is designed to achieve accurate tracking of air pressure and air flow by controlling the motor voltage of the air compressor and the opening of the back pressure valve. Under load disturbances, compared with feedback linearization control, improved tracking and robust performances of the proposed strategy can be exhibited through offline and online tests, the net power of PEMFCs is increased by 3%.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-15T01:37:20Z
      DOI: 10.1177/09544070231172239
       
  • Research on active safety control for heavy multi-axle vehicles under
           steering system failure

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      Authors: Qihui Liu, Heng Du, Yajin Yu, Hui Huang, Yunchao Wang, Jinhui Fang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Heavy multi-axle vehicles with long bodies, large loads, and many steering axles are prone to one stuck axle with its steering system failed, which leads to a sharp drop in vehicle safety. Modulating the steering angles of the remaining non-faulty axles for compensation control can significantly improve the safety of the vehicle. Therefore, this paper proposes a method based on multi-axle steering compensation, which solves the large trajectory error, and instability of heavy multi-axle vehicles caused by the failure of one-axle steering system. Firstly, based on the Lyapunov method, and nonlinear model, the critical steering angle of the faulty axle leading to vehicle instability under the failure of one-axle steering system is clarified, which provides a quantitative index for vehicle stability evaluation. Then, a two-level controller is designed to maintain stability and reduce trajectory error of the faulty vehicle. The upper dual-input dual-output (DIDO) sliding mode controller (SMC) compensates for the faulty vehicle’s lateral force and yaw moment. And the lower controller distributes the non-faulty axles’ steering angles through a strategy considering tire workload and slip energy dissipation. Finally, a seven-axle vehicle model in the Trucksim and a Trucksim-Simulink co-simulation are used to verify the effectiveness of the proposed method. The results illustrate that the proposed method can maintain vehicle stability and reduce the lateral trajectory error by about 22%–91% in the failure of one-axle steering system. It proves that this method can provide a new scheme for active safety control of heavy multi-axle vehicles.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-15T01:06:23Z
      DOI: 10.1177/09544070231172136
       
  • Temperature field model of limited slip clutch based on dynamic heat flux
           partition characteristics

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      Authors: Jiaxi Jin, Shujun Yang, Zengxiong Peng, Xueliang Li, Hui Pan, Zhuang Lian, Haidi Yi
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The interaxle torque distribution of off-road vehicle is interfered with temperature field variation of limited slip clutch during long-time sliding, which is controlled by actual heat flux input. The equivalent heat dissipation model is created based on the suggested calculation method of convective heat transfer equivalent coefficient in various lubrication phases. Further, thermal equilibrium equations of friction pair nodes are solved to produce the temperature field calculation model of dynamic heat flux partition. A clutch sliding bench is set up to verify and analyze the effect of heat flux partition on temperature field by organizing different operating conditions. The results demonstrate that the temperature difference of contact surface calculated by the constant heat flux partition model increases significantly along with sliding time and heat flux. In addition, the deviations of temperature rising rate at stage A and average temperature at stage B of separator plate higher than the experimental result also increases. On the contrary, the decrease value of actual input heat flux of separator plate from initial to steady state gradually increases with the increase of relative speed difference in dynamic heat flux partition model. The calculation deviations of temperature rising rate and average temperature are less than 0.1°C/s and 3°C, respectively. This model offers a novel approach for calculating clutch temperature field.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-12T11:21:59Z
      DOI: 10.1177/09544070231172812
       
  • Coordinated control algorithm of lateral stability of hybrid electric
           commercial vehicle

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      Authors: Xiaohua Zeng, Haoming Gao, Dafeng Song, Liangyu Li
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Focusing on the problem of mutual interference between the vehicle controller and the lateral stability control system in the stability control of hybrid electric vehicles (HEV), this study proposes a coordinated control algorithm for hybrid power systems and lateral stability, which can meet the real-time control requirements of the vehicle stability. First, the overall architecture of coordinated control between the hybrid power system and the vehicle lateral stability control system is designed. The judgment logic of lateral stability control system intervention and exit is determined on this basis. Second, in the upper layer of the control algorithm, the model predictive control algorithm is used to calculate the additional yaw moment required to maintain stability control under lateral instability of the vehicle with the vehicle two-degrees-of-freedom model as a reference. The motor output torque control and braking force distribution are then carried out in the lower layer of the control algorithm. The target braking wheel is determined according to the oversteering and understeering state of the hybrid vehicle. The additional yaw torque distribution control is formulated based on the quadratic programing algorithm. The strategy is to perform dynamic compensation for unstable or critically unstable vehicles to solve the optimal control problem under multiple constraints. Finally, through Matlab/Simulink and Trucksim co-simulation and hardware-in-the-loop test, the validity and real-time performance of the control algorithm proposed are verified to solve the interference problem in the lateral stability control process of HEVs and further improve the stability of vehicle rideability and active safety.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-09T05:49:58Z
      DOI: 10.1177/09544070231169552
       
  • Fatigue optimization of shock absorber coupling rod bracket based on ARIZ
           and finite element analysis

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      Authors: Yu Zhenhuan, Zhang Na
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Coupling rod bracket, which responds for connecting shock absorbers to coupling rods, is one of safety related parts in vehicle suspensions. During vehicle maneuvering, coupling road bracket will suffer the dynamic load caused by uneven roads. Fatigue life bench test shows that the cracks around bracket holes are unacceptable, which is a security risk. Therefore, in this paper, ARIZ (Algorithm for Inventive Problem Solving) algorithm is employed to generate optimization schemes. Further, finite element analysis was applied to compare pre-optimized and optimized solutions, which will give the optimal solution of coupling rod bracket. Finally, fatigue life bench tests were carried out to verify the optimized shock absorber coupling rod bracket. Simulation results show that 39% reduction in stress concentration of the optimized coupling rod bracket can be realized based on the proposed optimization scheme. Experimental results show that the bracket crack is less than 5 mm which can eventually satisfy customer requirements. Research in this paper finally indicates the applicability and reliability of the proposed ARIZ and finite element based method in the actual production process.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-08T12:52:26Z
      DOI: 10.1177/09544070231173062
       
  • Model reference backstepping control for semi-active air suspension
           systems with parameter uncertainty

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      Authors: Pak Kin Wong, Mengqi Deng, Jing Zhao, Meisam Ahmadi Ghadikolaei, Hang Wang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The electronically controlled semi-active air suspension systems have been widely used to improve the vehicle ride comfort and road holding performance by adjusting the damper stiffness. This work focuses on the design of a damping force controller to enhance the ride comfort, road holding and stability under the presence of unknown air spring pressure. Firstly, an improved skyhook suspension reference model is developed to generate the desired dynamic criteria (i.e. vehicle body acceleration, pitch and roll angles). Secondly, by employing the backstepping technique, a novel damping force controller is proposed to approach the desired dynamic criteria. Thirdly, a parameter estimation method is also designed to estimate the air spring pressure to obtain the air spring force. Comparative studies are carried out among passive suspension systems, and the semi-active air suspension systems with the proposed model reference damping force control, traditional backstepping control and existing sliding mode control. Numerical results show that a significant improvement of ride comfort can be observed with the semi-active air suspension system based on the proposed model reference backstepping controller.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-08T11:46:56Z
      DOI: 10.1177/09544070231173168
       
  • In-wheel drive system design with dynamic vibration absorption based on
           the adaptive transmission mechanism

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      Authors: Xinbo Chen, Aijing Kong, Wei Wang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The extra unsprung mass introduced by the propulsion motors becomes an unavoidable issue for electric wheel drive systems, resulting in deteriorated ride comfort and tire adhesion stability. This study presents an innovative wheel drive system based on the dynamic vibration absorber (DVA) to suppress the unsprung mass vibration, improving the suspension dynamic performance. Specifically, we apply the principle of adaptive transmission to generate an extra degree of freedom (DoF), enabling the propulsion motor to work as the DVA. Innovative solutions with different topologies are exploited and an appropriate one is selected for a specific chassis platform. Based on the quarter-suspension dynamics with 3 DoF, the optimal design regarding the component sizing and stiffness/damping characteristics of unsprung mass suspension is carried out to minimize the vertical body acceleration and dynamic tire load through the genetic algorithm. In practical application, bench tests of the prototype prove that the proposed electric wheel drive system has reasonable driving efficiency and torque tracking performance, which verifies the feasibility of the proposed structure.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-08T11:27:35Z
      DOI: 10.1177/09544070231172237
       
  • Knock metrics experimental evaluation for pre-chamber SI engines

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      Authors: Nathália Duarte Souza Alvarenga Santos, Igor Rodrigues dos Santos, Vinícius Rückert Roso, Carlos Eduardo Castilla Alvarez, José Guilherme Coelho Baeta
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The present study analyzes the occurrence of pressure oscillations in engines operating with pre-chambers at stoichiometric conditions, aiming to assess whether the increase in the amplitude of pressure oscillations detected by means of cylinder pressure measurements is related to knock, or it is a result of mass transfer from the pre-chamber to the main chamber. Initially, a literature review of the phenomenon is conducted and several knock indicators are used to evaluate experimental data obtained with a commercial four-cylinder SI engine, equipped with pre-chamber ignition system prototype, at 1500 rpm and 4 bar of IMEP. Among the knock indicators analyzed the excitations of resonance modes, the angle and time-based maximum pressure rise rate, maximum amplitude of pressure oscillations, ringing intensity, and adapted knock index can be cited. Furthermore, a study of the predominant pre-chamber ignition mechanism is carried out, distinguishing torch and jet ignition, which is also correlated with knock occurrence. Therefore, the present study shows the importance of conducting an individual knock analysis for each pre-chamber configuration and presents adequate tools for such a study, in order to guarantee engine integrity while exploring the benefits of the system, without limitations of inappropriate knock thresholds.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-08T11:15:16Z
      DOI: 10.1177/09544070231171963
       
  • Multi-coupled biomimetics for tire noise reduction

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      Authors: Guolin Wang, Lei Wang, Kexin Zhu, Yang Jian, Lin Bo
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      To explore ways of reducing tire noise, a 205/55R16 KR10 semi-steel radial tire was used as the research object. Vibration noise and aerodynamic noise were analyzed using the modal transfer vector method and the computational fluid dynamics method respectively. The cat’s paw pads can swivel left to right when walking, which dampens vibrations. The left-right pivoting characteristics of the cat’s paw pads are successfully transplanted into the tire by opening asymmetric bypass tube grooves in the tread to form a bionic tire. The results showed that the bionic tire can effectively decrease vibration noise. However, without considering the bypass tube’s resonant muffler acoustic noise reduction, the bionic tire increased aerodynamic noise. According to the multi-coupling bionic concept, the shark scale shield structure is coupled based on the bionic tire, and the shark-like structure is targeted at the sound source to form a multi-coupled bionic tire. Characterized by the left and right pendulum positive damping motion of the cat’s paw pad as well as the non-smooth damping structure of the shark scale shield, the multi-coupled bionic tire jointly reduced the tire vibration noise and aerodynamic noise.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-06T09:49:44Z
      DOI: 10.1177/09544070231173184
       
  • Research on simulated operational path analysis applied to structure-borne
           road noise

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      Authors: Xiaolong Li, Chihua Lu, Yawei Zhu, Yi Sun, Wan Chen, Can Cheng
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The accurate identification of noise sources inside vehicles is the basis of optimizing structure-borne noise problems, and transfer path analysis (TPA) is one of the most commonly used methods. The load-response type TPA represented by the classical TPA has high accuracy but low experimental efficiency. The response-response type TPA represented by the Operational TPA (OTPA) has high efficiency but cannot guarantee its accuracy when the relevant excitation sources act on the system simultaneously or there is a strong coupling between the transfer paths. In this paper, a novel response-response type TPA, simulated operational path analysis (SOPA), balancing efficiency and accuracy is proposed and tested. Without severing the connection between the source and receiver, the system is decoupled by running the simulated loads separately, and the proposed inverse transmissibility matrix method is used to cancel the crosstalk between reference signals, thus solving the problems of path cross-coupling and path neglection of OTPA in multi-input systems. For validation purpose, a four-shaker bench test is analysed, it is found that SOPA is more accurate than OTPA in path contributions analysis. Finally, SOPA is applied to the transfer path analysis of structure-borne road noise inside the vehicle, and it is also shown that the noise can be well predicted. Therefore, the proposed method may be an alternative method in addition to the traditional source-path-contribution analysis.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-06T09:41:04Z
      DOI: 10.1177/09544070231172240
       
  • Driving cycle prediction based on Markov chain combined with driving
           information mining

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      Authors: Ling Li, Haochen Sun, Fazhan Tao, Zhumu Fu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Driving cycle prediction (DCP) is of great importance for vehicle’s awareness of surrounding environment and optimization of control strategy. It has won much attention around the world. However, the used driving database could not reflecting the great diversity in multi driving cycles in real world. The characteristic parameters could not represent the complex and diverse driving conditions. Therefore, DCP models’ adaptability and generalization ability are limited. Moreover, prediction methods in existing researches always take large computation burden, difficult to apply in practice. To tackle these issues, the present research focus on DCP based on Markov chain combined with driving information mining (DIM). Firstly, many standard test cycles and real cycles are collected to construct an database of great diversity. Secondly, DIM technologies are studied to extract the optimal parameter set reflecting driving characteristics and determine the driving cycle categories. Thirdly, prediction method based on recursive self-learning Markov chain is proposed. Recursive equation of Markov state transition probability matrix (TPM) is deduced to save computation time. The key parameter of prediction method is adjusted to achieve optimal prediction performance. Synthesized standard test driving cycles (SSTDC) and real driving cycles (RDC) in database, as well as a new real driving cycle (NRDC) are tested. Driving pattern prediction accuracy of the proposed method is 99.25% for SSTDC, 100.00% for RDC, and 99.84% for NRDC, respectively. Compared with the benchmark method, the prediction accuracy is improved by 18.87% for SSTDC, 10.07% for RDC and 23.51% for NRDC, respectively. In addition, processing time of the prediction program is significantly reduced by 2.23 s (36.14%) for SSTDC, 12.30 s (51.25%) for RDC and 3.99 s (52.16%) for NRDC, respectively. It can be verified that the proposed method has high precision, short response time, as well as good adaptability and charming generalization ability for new cycles.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-05-06T09:34:25Z
      DOI: 10.1177/09544070231171741
       
  • Study on the altitude adaptability of single-stage and two-stage
           turbocharging systems for a heavy-duty diesel engine

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      Authors: Kangbo Lu, Huiyan Zhang, Tao Sun, Xuyang Tang, Lei Shi, Kangyao Deng
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      It is important to understand the altitude adaptability of the turbocharging system for maximizing its potential in the power recovery of the diesel engine at high altitudes. This study investigated the influence of altitudes ranging from 0 to 4500 m on the performance of the single-stage and two-stage turbocharging systems in a heavy-duty diesel engine. The research was conducted using a six-cylinder, four-stroke, turbocharged, direct-injection diesel engine. An altitude simulation test bench was used to simulate altitudes of 0 to 4500 m by adjusting the temperature and pressure. According to the test results, the altitude adaptability of different turbocharging systems was analyzed based on turbine work and turbocharger efficiency. It was concluded that the high-pressure stage regulation in the two-stage turbocharging system (HRT) strengthens the regulation ability in turbine work, effectively regulating the boost pressure and maintaining high turbocharger efficiency at different altitudes. The HRT can satisfy the regulation ability for altitudes ranging from 0 to 4500 m. The low-pressure stage regulation in the two-stage turbocharging system (LRT) weakens the regulation ability in turbine work and relies on reduction of the turbocharger efficiency to regulate the boost pressure. The LRT ineffectively regulates the boost pressure at low altitudes, with altitude adaptability from 1500 to 4500 m. Due to the exhaust temperature limitation, the waste-gate in the single-stage turbocharging system (WG) is not suitable for large-span regulation to satisfy the performance of the diesel engine at altitudes above 3,000 m compared with the HRT and LRT.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-29T11:29:03Z
      DOI: 10.1177/09544070231171970
       
  • Hierarchical coordinated control of multi-axle steering for heavy-duty
           vehicle based on tire lateral and longitudinal forces optimization

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      Authors: Heng Du, Xiaowei Zhu, Qihui Liu, Tianyu Ren, Yunchao Wang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Traditional multi-axle steering vehicle often adopts linear state feedback control, which is difficult to ensure high-precision trajectory tracking under all working conditions. Moreover, due to the failure to consider the optimal distribution of tire lateral and longitudinal forces, tires are prone to problems such as uneven load rates and wear. In this paper, considering the over-redundant and nonlinear characteristics of three-axle vehicle, a hierarchical coordinated control strategy is proposed. In the upper layer, the trajectory tracking controller is designed based on the robust nonlinear sliding mode control theory. In the middle layer, based on the optimization conditions of tire load rate and dissipative energy, the lateral and longitudinal forces optimal distribution controller is constructed under the constraint of friction circle. In the lower layer, the lateral and longitudinal forces are finally converted into tire angles and torques with the tire inverse model. The results show that the hierarchical coordinated control strategy can ensure that the multi-axle vehicle can achieve high-precision trajectory tracking under all-terrain load conditions, and the load rate and wear of each tire are relatively uniform. The coordinated control strategy proposed in this paper considers the influence of nonlinear characteristic of vehicle and tire lateral and longitudinal forces distribution on steering coordination, which can provide an important theoretical basis for the further improvement of steering coordination of multi-axle vehicle.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-28T07:16:28Z
      DOI: 10.1177/09544070231170665
       
  • Autonomous overtaking control considering the velocity change of obstacle
           vehicles on two-lane highways

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      Authors: Rong Yang, Lin Yang, Wei Huang, Junming Huang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Aiming at the speed change of obstacle vehicles in the process of autonomous ground vehicle (AGV) overtaking on two-lane highways, an overtaking control method including trajectory planning and trajectory control is proposed. First, the reference overtaking trajectory of the AGV is planned in stages (lane changing, passing and merging) using fifth order polynomials satisfying stability and comfort constraints. The initial planning trajectory may be unsafe due to the speed change of obstacle vehicles. So a collision prediction algorithm is built to predict two kinds of dangerous situations in real time: AGV collides with the leading vehicle during lane changing, and AGV collides with the oncoming vehicle during merging. Secondly, the potential field of the obstacle vehicles embedded with the relative speed is established and combined with the road potential field as the risk indicator. Then, combining the nonlinear model predictive control algorithm and risk index, the overtaking trajectory is replanned in real time with the initial trajectory as reference. Finally, a lateral path tracking controller based on model predictive control and a longitudinal speed tracking controller based on sliding mode control are established to track the planned trajectory rapidly and stably. To verify the performance of the proposed method, overtaking in three cases is simulated, and vehicle responding curves are obtained. The results show that the proposed control method can achieve safe and stable overtaking.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-20T06:22:32Z
      DOI: 10.1177/09544070231168305
       
  • Sensorless optimal control of electronic wedge brake based on dynamic
           model and Kalman filter state multiple-estimation

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      Authors: Mahmoud Said Jneid, Máté Zöldy, Péter Harth
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      An electronic wedge brake is a brake-by-wire system developed by some major companies in the domain of the automotive industry. The inherent self-reinforcing feature of the electronic wedge brake is interpreted as reduced actuation force and hence lower actuation energy. Controlling the electronic wedge brake requires measuring the clamping force using a force sensor, which requires special techniques to be installed onto the system and maintained safe from extreme conditions. This way the system design will be more complex, and the cost is increased due to the sensor expense. In this paper, a new sensorless optimal control (Servo-Linear Quadrature Regulator) approach is proposed using system dynamic-based estimation and Kalman filter-based estimation for clamp force control of electronic wedge brake. The suggested control scheme eliminates the need for clamp force and motor speed sensors by state multiple-estimation using only the current measurement of the motor. First, the motor current is measured and used to estimate motor speed relying on system dynamic equations. Brake wedge speed and position are then approximately derived in terms of the motor state estimates. The resulting current-based state estimates are eventually introduced to the Kalman filter as state measurements and used with the system control input calculated by the optimal controller to correct and update state prediction in the Kalman filter.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-20T06:20:34Z
      DOI: 10.1177/09544070231168168
       
  • Stability control of distributed drive electric vehicle based on adaptive
           fuzzy sliding mode

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      Authors: Xinxin Kong, Zhaowen Deng, Youqun Zhao, Wei Gao
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      To improve the driving stability of a distributed drive electric vehicle (DDEV), we propose a hierarchical direct yaw moment control strategy. In the upper-level controller, an adaptive fuzzy sliding mode controller (AFSMC) is designed with joint control objectives of sideslip angle and yaw rate. In the conventional controller, the weight coefficients of the joint control objectives are fixed values, which reduces the adaptability of the system. To improve this problem and achieve adaptive adjustment of the weight coefficients of the control objectives with the vehicle motion state, an adaptive fuzzy control-based target weight coefficient controller is designed. In the lower controller, a quadratic programing method is used to assign torque with the optimization objective of minimizing tire attachment utilization. A joint simulation with Carsim and Simulink software was performed to compare and analyze the AFSMC vehicle and the traditional SMC vehicle under the steering wheel turning angle sinusoidal input and double shift line conditions. The results show that AFSMC effectively reduces the magnitude of vehicle sideslip angle, yaw rate, and lateral acceleration, enhances the driving stability of the vehicle, and enables adaptive adjustment of the weight coefficients of the joint control objectives, improving the adaptability of the controller. Finally, the effectiveness of the control strategy is verified by hardware-in-the-loop (HIL) test.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-15T05:47:43Z
      DOI: 10.1177/09544070231169804
       
  • A fusion estimation of tire vertical forces using model-based tire state
           estimators for a dual-sensor intelligent tire

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      Authors: Delei Min, Yintao Wei, Tong Zhao, Junxiang He
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Estimating tire vertical forces is essential to vehicle state estimation and stability control. Intelligent tires can be used to estimate tire vertical forces, but functional safety and extensive tests are issues to consider during intelligent tire development. This paper proposes a fusion estimation approach using model-based tire state estimators (TSEs) to estimate the tire vertical forces of a dual-sensor intelligent tire, which can output the circumferential strain, radial, and circumferential acceleration signals with a strain sensor and an accelerometer mounted at different positions on the inner liner. The mutual conversion between strain and acceleration signals is indicated in this paper for the first time; therefore, the internal relationship between different signals is revealed. Each measurement signal of the two sensors corresponds to a TSE composed of a signal processing algorithm, a mathematical model, and a Kalman filter. The mathematical model is proposed in this paper based on the flexible ring tire model (FRTM). The final estimated value of the tire vertical force is obtained by weighting and summing the outputs of the three TSEs. The weighting factors are determined using the genetic algorithm to study the fusion estimation effect. An integrated CarSim model is built in this paper to validate the estimation performance under various driving conditions, including driving straight at a constant speed, driving on an S-shaped road, and performing a double lane change at a high vehicle speed. For all driving conditions, the mean error rates of the fusion estimation are less than 2%. The model-based tire state estimators can avoid the extensive tests needed in the data-based methods. Furthermore, the fusion of the outputs of three TSEs can further improve the estimation performance compared with the situation when a single TSE is used. Therefore, the studies in this paper have guiding significance for intelligent tire development.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-15T05:38:41Z
      DOI: 10.1177/09544070231168921
       
  • Regenerative braking torque compensation control based on improved ADRC

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      Authors: Linfeng Zhao, Ning Wang, Guang Xia, Xueqing Mei, Huiran Wang, Dingzhi Zhang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Electro-hydraulic braking (EHB) compensation is an effective method to solve the insufficient regenerative braking of electric vehicles, but the accuracy and speed of executive pressure response are still insufficient. In order to solve this problem, a brake pressure compensation control method based on EHB system is proposed and verified. Firstly, adaptive LuGre friction model and braking dead time compensation are introduced to obtain a more accurate friction model. Then, an electro-hydraulic braking control strategy based on Improved Active Disturbance Rejection Control (IADRC) is proposed. Finally, the effectiveness of the proposed method is verified by simulation experiments and hardware-in-the-loop (HIL) simulation experiments. The test results show that the proposed control method can achieve accurate control of brake pressure compensation in time. The research results promote the research and application of EHB system to a certain extent.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-15T05:36:44Z
      DOI: 10.1177/09544070231165823
       
  • Multi-agent deep reinforcement learning with actor-attention-critic for
           traffic light control

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      Authors: Bin Wang, ZhengKun He, JinFang Sheng, YingXian Liu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In recent years, with the increase of urbanization and car ownership, urban traffic congestion have become increasingly prominent. Traffic light control can effectively reduce urban traffic congestion. In the research of controlling traffic lights of multiple intersections, most methods introduced theories related to deep reinforcement learning, but few methods considered the information interaction between intersections or the way of information interaction is unreasonable. Inspired by this, this paper proposes a multi-agent deep reinforcement learning with actor-attention-critic network for traffic light control (MAAC-TLC) algorithm. In MAAC-TLC, each agent introduces the attention mechanism in the process of learning, so that it will not pay attention to all the information of other agents indiscriminately, but only focus on the important information of the agents that plays an important role in it, so as to ensure that all intersections can learn the optimal policy. Finally, the traffic lights at each intersection in the MAAC-TLC algorithm are controlled according to its own policy, thereby improving the traffic efficiency of the traffic network. The experimental results on light and heavy traffic flow scenarios have demonstrated that MAAC-TLC can improve traffic congestion at multiple intersections effectively.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-13T11:31:05Z
      DOI: 10.1177/09544070231167986
       
  • Research on the durability test method of electric driving systems based
           on fuzzy clustering and particle swarm algorithm

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      Authors: Xicheng Wang, Yufan Cheng, Tianxiang Yu, Bifeng Song
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Compared to traditional fuel vehicles, the structure of pure electric vehicles (BEVs) and the actual driving behaviour of users have changed. Therefore, the original durability evaluation conditions of traditional fuel vehicles cannot fully cover the use of new energy vehicles. In the past, the determination of durability targets was mainly based on user data collection, but this work required a lot of manpower and material resources to meet the engineering requirements. In this paper, the fuzzy clustering method is used to mine the user trajectory to obtain the user-based endurance target of pure electric vehicle, and then according to the durability target, the particle swarm method is used to correlate the user behaviour and the proving ground, and the proving ground test method of electric drive system is developed. Studies have shown that user data mining methods can obtain more user information, so as to better formulate durable target close to users. The particle swarm algorithm can improve the simulation correlation accuracy and reduce the iteration time, which shortens the simulation iteration time by more than 80% compared with polynomials. The test acceleration ratio of 7:1 in relation to user behaviour with the proving ground. During the durability test of the electric drive system of pure electric vehicles, it is found that the test specification can well reflect the user’s motor operation during actual driving.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-13T11:26:48Z
      DOI: 10.1177/09544070231167891
       
  • The influence of contact distribution shaping on the dynamic response of a
           wiper blade

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      Authors: Bradley Graham, James Knowles, Georgios Mavros
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The primary function of windscreen wipers is to remove water and debris from the windscreen, ensuring the driver has a clear view of the road ahead. Predicting wiper performance at the design stage is therefore important to ensure their safe operation. There is hence a need to develop physics-based models of wiper performance that can be used as evaluative tools early in the design stage. This paper presents an analysis of the impact of changing screen curvature on the contact force distribution of a wiper blade and the subsequent effects on the transient dynamics. The contact distributions for three distinct screen curvatures and three loading points are calculated via FEA (finite element analysis) and subsequently analysed via multiple connected mass spring dampers to model the wiper blade lip transient dynamics. By analysing time and frequency domain data for several calculated contact distributions it is found that decreasing the screen curvature reduces the contact force at the centre of the blade, however, increases the amplitude of vibrations and range of frequencies observed. Additionally, it is found that moving the loading point towards the tip of the blade reduces the amplitude of vibrations, a result analogous to that of increasing the screen curvature. Based upon the understanding gained through this work the influence of design criteria on wiper blades can now be assessed, and several suggestions made as to how to reduce windscreen wiper noise.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-13T11:21:14Z
      DOI: 10.1177/09544070231164792
       
  • Semantic closed-loop based visual mapping algorithm for automated valet
           parking

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      Authors: Haobin Jiang, Yixiao Chen, Qingyuan Shen, Chenhui Yin, Junyu Cai
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Simultaneous localization and mapping (SLAM) is one of the core technologies to realize automated valet parking (AVP). Currently, advanced visual feature-based SLAM systems suffer from feature extraction failure and tracking loss due to the constraints of textureless scenes, unclear illumination, and dynamic conditions. To address these problems, this paper proposes a visual SLAM algorithm based on a semantic closed-loop detection algorithm using surround-view cameras and inertial measurement units (IMU) as sensors. The algorithm combines semantic features and the idea of inverse index to improve the traditional keyframes selection methods and the closed-loop detection algorithms, effectively avoiding the tedious and complicated feature point matching and improving the computational efficiency of the computer. Experiments show that the algorithm in this paper achieves better results in terms of precision and recall, absolute trajectory error (ATE), and relative pose error (RPE), and can meet the demand for SLAM and subsequent navigation in indoor parking lots.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-12T12:39:03Z
      DOI: 10.1177/09544070231167639
       
  • Model based integrated control strategy for effective brake energy
           recovery to extend battery longevity in electric two wheelers

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      Authors: Bragadeshwaran Ashok, Chidambaram Kannan, Chirag Deepak, Rathan Ramesh, Tharun MV Narendhra, Mohamed Emad Farrag, Sathiaseelan Denis Ashok, Rajasekar Vignesh, Pemmareddy Saiteja, Chellapan Kavitha
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      This study aims to achieve optimal regenerative braking performance in the form of a reduced decline in battery SOC for a BLDC electric machine with peak torque of 10 Nm for use in electric two-wheelers. This is conducted via a comparison of control algorithms based on Direct Look-up table, Fuzzy Logic and their combination with PID control. The whole vehicle model and the energy recovery control strategies are designed using MATLAB Simulink by benchmarking the design with the parameters of the Ola Electric S1. A physical motor-dynamometer test bench is utilised to obtain a complete motor operating range to derive a realistic efficiency map that is used in the model. WLTP Class 2 and NYCC standard drive cycles are implemented for vehicle simulation. Two live-recorded driving patterns are also used to validate the model to analyse the adaptability of the control strategies. After obtaining the required motor speed, torque values and the range by matching the theoretical drive cycle profile, the control strategy is further optimised using the PID auto-tuning toolbox in Simulink. Using physical testbench data, the effect of various regenerative braking control strategies on overall vehicle performance is more accurately realised. The Fuzzy PID control strategy exhibits the most optimal gains in terms of energy recovery for electric two-wheelers, allowing for the highest battery SOC levels of 41.88% and average motor regenerative torque of 7.25 Nm for the standard drive cycles. An analogous trend is observed for the on-road driving pattern as Fuzzy PID provides highest battery SOC and average motor regenerative torque of 48.34% and 7.5 Nm respectively. For the driving scenarios aforementioned, this provides a 17% and 44% increase in SOC respectively when compared to a non-regenerative braking-based system.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-12T12:31:43Z
      DOI: 10.1177/09544070231167616
       
  • Research on improved driver model based on vehicle-road security situation
           under large curvature curves

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      Authors: Bixin Cai, Qidong Wang, Mingyue Yan, Linfeng Zhao, Wuwei Chen
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Unreasonable path planning will make the vehicle prone to traffic accidents when driving at a limited maximum speed in the case of the low-speed situation and large curvature curve conditions. Considering the defects of neural network model based on the data-driven may cause unexpected results, an improved driver model was proposed to enhance driving safety. In this paper, the Dempster/Shafer evidence theory was used to detect critical features of lane lines for situation detection. And an observer was established to observe and analyze the model output based on the vehicle space motion safety and driving stability characteristics. Then, an optimizer was established to optimize the output and provide the optimal driving trajectory according to the analyzed situations. Finally, it is verified that the proposed algorithm can help the vehicle safely pass the ample curvature curves by the simulation platform and real vehicle in the laboratory.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-12T12:25:19Z
      DOI: 10.1177/09544070231166733
       
  • Neural network optimization algorithm based non-singular fast terminal
           sliding-mode control for an uncertain autonomous ground vehicle subjected
           to disturbances

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      Authors: Lhoussain El Hajjami, El Mehdi Mellouli, Vidas Žuraulis, Mohammed Berrada, Ismail Boumhidi
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      As computer computing capabilities increase, optimization algorithms are becoming more useful for solving engineering problems. Up to now, several metaheuristic algorithms have been exploited in control engineering. However, this effort remains weak in addressing the autonomous ground vehicles (AGVs) trajectory tracking problem. This research presents a novel optimal approach merging the robust non-singular fast terminal sliding-mode control method (NFTSMC) and the neural network optimization algorithm (NNA) for automatic lane changing. First, a reference double lane-change path (DLC) is designed, and the robust non-singular fast terminal sliding-mode steering controller is developed, according to Lyapunov stability theory, to suppress the lateral deviation and ensure the yaw stability. Then, the control strategy is optimized by the NNA algorithm to adjust the steering controller optimally while avoiding local optimums. A comparison, under the same conditions, with the particle swarm optimization algorithm (PSO) revealed the superiority of the control law resulting from the NNA-based optimization. Furthermore, the proposed approach shows its excellent tracking performance versus the integrated backstepping sliding-mode controller (IBSMC) and the adaptive sliding-mode control (ASMC) under severe conditions typical of real-world lane changes.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-11T11:49:11Z
      DOI: 10.1177/09544070231169117
       
  • Study of direct water injection on knock suppressing and engine
           performance of a gasoline engine

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      Authors: Zhijun Wu, Min Gao, Rui Cao, Jingtao Wu, Jun Deng
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Turbocharger technology has become an essential method for the internal combustion engine to improve fuel economy. However, too high a boost pressure leads to too high a temperature in the combustion chamber at the end of the compression stroke, which can cause knocking or worsen abnormal combustion. Water injection technology plays a role in cooling the intake air and components in the cylinder, which can control the combustion process and suppress knock. This work focused on the influence of direct water injection (DWI) on knock suppression and efficiency improvement using a small turbocharged gasoline engine, investigating the fuel-saving potential of DWI and the optimal strategy of DWI for different engine operating conditions. Taking knock intensity (KI) as the evaluation index, KI decreases from 0.052 to 0.04 MPa, and knock limit spark angle (KLSA) increases with increasing water injection. This work shows that the DWI strategy plays a critical role in earlier spark timing, optimized combustion phase, and improved efficiency. Fuel consumption decreases by 11.55% with the optimal DWI strategy at an operating condition of 2000 rpm and a brake mean effective pressure (BMEP) of 1.3 MPa. Moreover, the optimal water injection timing is at −180°CA under various engine loads. Due to the stronger knock tendency under higher load conditions, the knock suppression is less effective for the same amount of water, so more water injection mass is necessary for higher efficiency.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-07T05:03:07Z
      DOI: 10.1177/09544070231166039
       
  • Hybrid attention based vehicle trajectory prediction

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      Authors: Lingyang Wang, Wenping Jiang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Accurately predicting trajectory of vehicles is a key capability for autonomous vehicles during real-world driving scenarios, which requires the autonomous vehicles to perceive the surrounding environment and analyze the track histories to judge the driving intentions of the focused surrounding vehicles in order to make decisions for the next trajectory route. In this paper, we propose a hybrid attentional trajectory prediction model incorporating both temporal attentional and spatial attentional mechanisms, which has a temporal attentional model that can be used to capture important temporal information affecting trajectory prediction and a spatial attentional mechanism that can better introduce spatial dependencies and potential driving intention information of surrounding and target vehicles. The models are evaluated for performance on publicly available highD and NGSIM datasets. By comparing the results with other state-of-the-art models for trajectory prediction, it is found that the model achieves an improvement in prediction performance, indicating that this model can more accurately learn driving information from the spatio-temporal perspective of the target driving vehicle’s attention. Further, by qualitatively analyzing the distribution of attention weights from the spatio-temporal perspective, we assessed the interpretability of the model on the maneuverability judgment of the vehicle.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-07T04:59:03Z
      DOI: 10.1177/09544070231165791
       
  • Analysis of the competitive situation among Chinese power battery
           enterprises based on T-M model

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      Authors: Zhensen Ding, Haifeng Fang, Zhanhui Yao
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      With the support of policies, the power battery industry has already been in the initial stage of high-quality development. However, it is difficult to effectively judge the development potential and competition situation of enterprises only through the overall installed capacity, while it is impossible to effectively use the “supporting the excellent and strong enterprises ” industrial policy and targeted industry funds. In this research, a power battery enterprise competitiveness evaluation model was constructed by considering two dimensions of technical competitiveness and market influence. Taking China’s mainstream power battery enterprises as the research object, the validity of the model was verified and the long-term competition of power battery enterprises was predicted by the bias value of lithium iron phosphate. The results show that: when the bias value of lithium iron phosphate is 0.3, A2 is the market chaser, A5 is the technology chaser, A3 performs well in both technology and market, but there is still a big gap by comparing with A1. When the bias value of lithium iron phosphate is 0.7, in terms of competition landscape, A3 and A5 become technical catchers, especially A3 with more obvious advantages, while A2 and A4 become market catchers, especially A2 with more obvious advantages; in terms of enterprises, the ranking of leading enterprises is almost unchanged, but there are major changes among those enterprises ranked in the middle and rear position. The research results can support the scientific use of industrial policies and industrial funds and promote the power battery industry to move into a high-quality development stage. In the next step, it is required to consider the huge impact of new system battery on the industrial structure and improve the robustness of the model.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-06T06:06:36Z
      DOI: 10.1177/09544070231167503
       
  • Objective evaluation index for the comprehensive performance of
           intelligent vehicle lane-changing trajectory

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      Authors: Qiaobin Liu, Lu Yang, Ming Gao, Bolin Gao, Jianqiang Wang, Keqiang Li
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Lane-changing behaviour is one of the most important and basic driving behaviours. Intelligent and connected vehicles must face lane-changing scenarios to achieve autonomous driving. To improve the rationality of lane-changing trajectory planning for intelligent vehicles, by analysing numerous real vehicle lane-changing trajectories in the German HighD natural driving dataset, a dimensionless lateral quantification balance index is proposed to realise a comprehensive and objective evaluation of the degree of human-likeness of lane change trajectory planning. Focused on the lateral kinematic characteristics of lane changing, a lane-changing trajectory extraction method based on the peak-to-peak value of lateral acceleration is proposed. Lateral displacement, lateral velocity, lateral acceleration and lane-changing duration are extracted from natural driving data, and the correlations between the parameters are revealed to deduce the lateral quantification balance index. With several common parametric lane-changing trajectory models of intelligent vehicles, such as sine, quintic polynomial, Gaussian and hyperbolic tangent and fifth-order Bessel models, as examples, the index values of each lane-changing trajectory model are calculated and obtained. Results show that the proposed index can balance the different requirements in lane-changing efficiency and comfort of the trajectory parameters during the lane-changing process, thus achieving a comprehensive quantitative evaluation of lateral stability, efficiency and comfort. This research establishes an intuitive and concise objective function for human-like trajectory planning and provides a basis for trajectory tracking control and real-time dynamic correction of intelligent vehicles.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-06T06:04:00Z
      DOI: 10.1177/09544070231161844
       
  • Probabilistic multi-modal expected trajectory prediction based on LSTM for
           autonomous driving

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      Authors: Zhenhai Gao, Mingxi Bao, Fei Gao, Minghong Tang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Autonomous vehicles (AVs) need to adequately predict the trajectory space of surrounding vehicles (SVs) in order to make reasonable decision-making and improve driving safety. In this paper, we build the driving behavior intention recognition module and traffic vehicle expected trajectory prediction module by deep learning. On the one hand, the driving behavior intention recognition module identifies the probabilities of lane keeping, left lane changing, right lane changing, left acceleration lane changing, and right acceleration lane changing of the predicted vehicle. On the other hand, the expected trajectory prediction module adopts an encoder-decoder architecture, in which the encoder encodes the historical environment information of the surrounding agents as a context vector, and the decoder and MDN network combine the context vector and the identified driving behavior intention to predict the probability distribution of future trajectories. Additionally, our model produces the multiple behaviors and trajectories that may occur in the next 6 s for the predicted vehicle (PV). The proposed model is trained, validated and tested with the HighD dataset. The experimental results show that the constructed probabilistic multi-modal expected trajectory prediction possesses high accuracy in the intention recognition module with full consideration of interactive information. At the same time, the multi-modal probability distribution generated by the anticipated trajectory prediction model is more consistent with the real trajectories, which significantly improves the trajectory prediction accuracy compared with other approaches and has apparent advantages in predicting long-term domain trajectories.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-06T05:35:26Z
      DOI: 10.1177/09544070231167906
       
  • An alternative switching filtered-x LMS algorithm for road impact noise
           control in vehicle

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      Authors: Hucheng Wang, Yansong He, Ziheng Xia, Zhifei Zhang, Zhongming Xu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      An adaptive switching FxLMS algorithm is proposed to deal with the problem that the performance of the active control system of interior noise drops sharply when come across road impact. According to the state of the system, the algorithm updates the weight coefficient of the control filter in two different ways. Firstly, the normalization algorithm is adopted to improve the convergence speed. After convergence, the relationship between iteration step size and residual error is established by using deformed Gaussian function. The adverse effects of road impact will be dealt with by a new iteration step. On the premise of increasing a small amount of calculation, it improves the convergence speed of the system and ensures the steady-state performance of the system. Numerical simulation and real vehicle test verify the effectiveness of the proposed algorithm in the face of road impact.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-06T05:23:46Z
      DOI: 10.1177/09544070231166727
       
  • Modeling and state-preview height control of electronically controlled air
           suspension system based on experiment

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      Authors: Yiming Long, Xiaoqiang Tan, Weijun Li, Yuxin Lai, Jiaming Xu, Guangqiang Wu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In the control of electronically controlled air suspension system (ECAS), the precision and stability of height control are important targets to measure the efficiency. In the control process of an ECAS system, the phenomenon of “overinflation,”“overdeflation,” and frequent inflating and deflating is commonly existed, which is rooted in the hysteresis characteristic of the system. Based on the bench test, the system identification and quantitative performance analysis of solenoid valves and air springs were carried out, and a refined ECAS system model was built. A PID control strategy is optimized and a state-preview height control strategy is established. AMESim and Simulink are used to build the vehicle and controller models. The accuracy of the model is verified by the comparison between the co-simulation and the field test, and the conclusion is drawn that the state preview height control strategy can improve the smoothness of the height control.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-06T05:18:07Z
      DOI: 10.1177/09544070231161210
       
  • Test methodology for validating tractor structural part under multiaxial
           loading

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      Authors: Abhirup Chakraborty, Kandavel Arunachalam
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      A tractor is a machine which is predominantly used for various agricultural operations such as plowing, tilling, planting, harvesting, etc. Apart from the regular agricultural applications, currently, tractor is being also used for various other applications such as haulage, dozing, loading, digging, and so on. Because of the versatility in usage patterns and applications, it is extremely difficult to estimate the loads coming on different structural parts of a tractor. Therefore, fatigue behaviors of different structural parts are also highly unpredictable. Limited test methodologies or information are available about the testing methodologies to validate the structural parts of a tractor. Conventional uniaxial load tests may not be sufficient to replicate actual Real World Usage Pattern (RWUP) as different structural failures are reported from field testing or end customers despite clearing in different lab testing. On the other hand, multiaxial loading may produce more realistic and accurate test results. In this paper, an attempt has been made to develop a practically deployable and simple to use laboratory test methodology considering multiaxial loading to validate Rear Axle Carrier (RAC) assembly of a tractor. At the end of the study, simple to put methodology has been demonstrated in which all the stated objectives were full filled. Real time acquired load data have been used to analyze and develop the duty cycle with a considerable test time reduction in place. This methodology can be used for validating similar kind of structures.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-05T11:18:40Z
      DOI: 10.1177/09544070231166986
       
  • Maneuver-based trajectory planning with fast collision check for
           autonomous vehicles in a low-speed road environment

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      Authors: Zheng Li, Yijing Wang, Zhiqiang Zuo
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      For autonomous vehicles driving in a low-speed road environment like complex campus, there are several peculiarities such as two-way lanes, break-in obstacles, smaller safety margin, etc. In this paper, a novel maneuver-based trajectory planning scheme is designed for autonomous vehicles driving in a low-speed environment with uncertain dynamic obstacles. First, a quintic polynomial is adopted to generate candidate trajectories and we develop a fast collision check algorithm to guarantee safety. In contrast to the existing methods, our collision check can reduce computation time with less conservatism. To balance the conflict between overtaking and lane-keeping, varying maneuvers are proposed to determine different weights in cost function for selecting the optimal trajectory. Simulations with uncertain low-speed obstacles are conducted to evaluate the performance of our proposed method.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-05T11:16:01Z
      DOI: 10.1177/09544070231166042
       
  • A model-based method of tire-road friction estimation for articulated
           steering vehicles

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      Authors: Lulu Gao, Shite Wang, Dongyue Wang, Fei Ma, Yueqi Dong
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Articulated steering vehicles (ASV) are widely used in many industries for their high efficiency and excellent maneuverability. The autonomous driving and intelligent control of ASV are extremely critical owing to the operation characteristics. As a very important parameter, the tire-road friction coefficient (TRFC) determines the extreme tire force directly in the process of intelligent control. However, it cannot be obtained with the existing methods for the harsh environment and special structure of ASV. This paper proposed a two-layer model-based method of tire-road friction coefficient estimation for ASV. The dynamic models of ASV in the XY plane, including the longitudinal and lateral models of frames, tire forces, and steering system models, are established first. The dynamic models are embedded into the upper layer with a Kalman filter (KF) to estimate the tire forces in longitudinal and lateral directions. During the process, some self-contained sensors, including the state sensors of frames and steering system, are used to provide the observation data. In the lower layer, a recursive least square (RLS) method with a forgetting factor is used to obtain the TRFC and tire stiffness parameters with the aid of the tire model. The simulation and field test are carried out to validate the method under comprehensive conditions, in which different steering commands, velocities, and roads are included. The simulation and field test results show that the forgetting factor has a significant influence on the convergence and robustness of the proposed method. The forgetting factor τ = 0.95 is used in the field test, the estimation result of dry concrete road friction coefficient is around 0.83. The results indicated that the proposed method can obtain the TRFC and tire parameters dynamically for ASVs.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-03T12:11:55Z
      DOI: 10.1177/09544070231165936
       
  • Effects of site operating conditions on real site TKPH
           (tonne-kilometer-per-hour) of ultra-large off-the-road tires

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      Authors: Shaosen Ma, Chengkai Fan, Wei Victor Liu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The objective of this study is to investigate the effects of site operating conditions on the real site TKPH (tonne-kilometer-per-hour) of ultra-large off-the-road (OTR) tires. To achieve this, a novel finite element OTR tire thermal (OTRTire-T) model was developed to predict the temperatures of OTR tires. As per the results from the OTRTire-T model, the cycle length coefficient K1 and the site ambient temperature coefficient K2 were refined and then compared with existing coefficients in the literature for cross-verification. After cross-verification, these K1 and K2 coefficients were used to calculate the real site TKPHs. The real site TKPHs were investigated under different site operating conditions (i.e. average vertical tire loads, average cycle speeds, ambient temperatures, and cycle lengths). The results showed that the real site TKPH increased with a rise in average cycle speeds from 10 to 45 km/h and an elevation of ambient temperatures from −30°C to 40°C. At low ambient temperatures below 15°C, as per the real site TKPH, the loading capacity of the truck may increase (compared with its rating payload of 363 t) at mine sites. In addition, the real site TKPH increased relatively rapidly when the cycle lengths were short but rose slowly, or even leveled off, with a further increase in cycle lengths.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-03T12:07:45Z
      DOI: 10.1177/09544070231166166
       
  • Active fault-tolerant control scheme for four-wheel independent drive
           electric vehicles under actuator faults

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      Authors: Weida Wang, Biao Hu, Chao Yang, Taiheng Ma, Yuhang Zhang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      For chassis-by-wire in four-wheel independent drive electric vehicles (4WID-EVs), a large number of controllable actuators with control systems and electrical systems make the vehicle more sensitive to the failure of electronic components in actuators. When actuator faults occur, the stability and handling performance of 4WID-EVs will deteriorate, even affecting the driving safety. To handle this problem, the typical actuator faults of 4WID-EVs and their characteristics are firstly analyzed in detail. After that, a control-oriented uncertain 7 degrees of freedom vehicle dynamics model is established. Then, a modified sliding mode active fault tolerant control (FTC) scheme with layered architecture is proposed, which contains the upper and lower layers. In the upper layer, a modified sliding mode controller with a nonlinear extended state observer is designed to track the reference states under the influence of model uncertainty. In the lower layer, an improved torque distribution algorithm is proposed to compensate for the limited direct yaw moment caused by in-wheel motor faults. Comparison works are carried out both in simulation and experiment. Simulation results show that the proposed method improves performance by 80.5% and 70.2% compared with existing FTC method under 2 fault conditions, respectively. Furthermore, real vehicle experiments also indicate that the proposed method improves performance by 59.6% and 74.4% under two pre-set fault conditions, respectively. The proposed method might provide a theoretical reference for actual controller design in 4WID-EVs.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-03T06:36:42Z
      DOI: 10.1177/09544070231166430
       
  • Roll dynamic model and steering stability analysis of the counterbalance
           forklift truck with considering hierarchical rollover

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      Authors: Yang Zhang, Jianwei Lu, Guang Xia, Amir Khajepour
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The dynamic model of a counterbalance forklift truck is established, and the validations under various operational conditions are studied. The roll motion of the counterbalance forklift is expressed by four degrees of freedom with consideration given to the independent roll motion between the body and chassis, the variation of the roll axis, and the contact between the body limit block and rear axle. Furthermore, testing under turning on firm ground and driving over obstacle conditions are conducted for verifying the dynamic response characteristic of the established model. In addition, numerical simulations are performed to investigate the effect of forklift structural parameters and road roughness excitation on the roll dynamics of forklifts. Finally, the rationality of evaluating the forklift roll state by load transfer ratio (LTR) is discussed. Simulation results are well in harmony with experiment results, suggesting that the proposed dynamic model can be an effective tool for stability analysis of counterbalance forklift trucks. This work provides theoretical foundations for the development of improved anti-rollover control, ultimately leading to enhanced stability and safety of forklifts.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-03T06:27:15Z
      DOI: 10.1177/09544070231161056
       
  • FEGNet: A feature enhancement and guided network for infrared object
           detection in underground mines

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      Authors: Lisha Huang, Xi Zhang, Miao Yu, Songyue Yang, Xiao Cao, Junzhou Meng
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Object detection plays an important role in underground intelligent vehicles and intelligent transportation systems. Due to the uneven light in underground mining scenarios, infrared cameras are one of the typical onboard sensors for environmental perception. Although object detection has been studied for decades, it still confronts the challenge of detecting infrared objects in underground mines. The contributing factors include weak and small objects in infrared images and similar environments in mining scenarios. In this paper, a Feature Enhancement and Guided Network (FEGNet) is proposed to address these problems. Based on the characteristics of infrared images, the feature enhancement module (FEM) preserves the image details from global and local perspectives to improve the discrimination of weak and small objects. To tackle the problem of overfitting caused by similar environments, a receptive-field-guided (RFG) backbone is proposed to learn multi-scale context and spatial information. The experimental results on the underground mining (UM) dataset demonstrate that the mAP of the proposed FEGNet achieves 86.1%, which is 4.6% higher than the state-of-the-art CNN-based network YOLOv7.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-04-01T10:24:08Z
      DOI: 10.1177/09544070231165627
       
  • Investigation of real-world emissions of China III and China IV buses in a
           high-altitude city: A case study of Lhasa

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      Authors: Meng Lyu, Yun Li, Meili Lyu, Boyang Li, Yanming Yang, Yanfen Wang, Mengyao Pan, Yunjing Wang, Ting Wu, Ronald Matthews
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Limitations still remain among vehicle emissions standards and regulations about high-altitude areas at altitude over 2400 m. In view of high vehicle-use intensity for buses, on-road measurements were performed on four heavy-duty diesel vehicles by employing a portable emissions measurement system (PEMS) in Lhasa, with an average elevation of approximately 3650 m. The result indicated that under real-world driving conditions of Lhasa, compared with China III buses, China IV buses did not show excellent emission performance consistently. For example, carbon monoxide (CO) emission factor of China III-5.2L buses is 2.4 times of China IV-5.2L buses, while the nitrogen oxides (NOx) is only 36% of China IV-5.2L. Furthermore, an operating mode binning and a micro-trips method are used to link real-world emissions of each vehicle to driving conditions. For China III-5.2L and China IV-5.2L buses, we found strong correlations between relative emission factors of carbon dioxide (CO2) and NOx and average speed. However, these correlations for China IV-7.8L bus were less strong. This phenomenon proves that the role of traffic conditions in affecting road driving emissions would be mitigated when selective catalytic reduction (SCR) functioning properly. This study have potential implications for policymakers concerning vehicle emissions management and control strategies, such as promotion of alternative fuel with in-used buses, aimed at emissions reduction.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-31T09:41:37Z
      DOI: 10.1177/09544070231163428
       
  • Parametric optimization for van drag reduction using a side flap

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      Authors: Fatima-Zahra Hachimy, Ashraf Omar, Omer Elsayed, Kenza Bouchaala
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In current study, the aerodynamic drag reduction of a simplified van model was numerically explored by mounting a side flap on the rear end, on the basis of ANSYS-Fluent, an established Computational Fluid Dynamics (CFD) software. A robust Taguchi test design method was leveraged to optimize the independent parameters related to side flap design in order to achieve the best combination for maximum drag reduction with minimum test numbers. The accuracy of the numerical study was validated using the benchmark, Ahmed body model. The current study outcomes established the efficiency of adding a side flap to weaken the longitudinal vortices, at the rear part of the van model, for the purpose of reducing the aerodynamic drag. In this study, the authors achieved a maximum reduction of 11.50% for total drag coefficient and 11.73% for pressure drag coefficient.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-30T12:36:27Z
      DOI: 10.1177/09544070231164200
       
  • Simulation analysis on vertical vehicle dynamics of three in-wheel motor
           drive configurations

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      Authors: David Drexler, Zhi-chao Hou
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The hub-driven technology provides several remarkable benefits to overcome some of today’s challenges in electrification of the transport sector. Although there are advantages by using in-wheel motors, their application results in increased unsprung masses, which have a negative impact on ride comfort and road holding of the vehicle. A novel but unexplored concept to inhibit the negative effects of the wheel hub motor is the two-stage-suspension structure. To investigate this in-wheel motor design and to compare it with established concepts for reducing the negative effects of the unsprung masses, three full-vehicle models were established. The vehicle models are based on a two-stage-suspension structure, a design where the motor functions as a tuned mass damper and a conventional in-wheel motor design. The suspension parameters of the three in-wheel motor configurations were further optimized using a genetic algorithm with respect to several vertical vehicle performance parameters. Subsequently, the full-vehicle models of the in-wheel motor configurations were compared by simulation in numerous different driving situations regarding their vertical vehicle dynamics. The results demonstrate that the two-stage-suspension causes an increase of the pitching and vertical vehicle body acceleration in several driving conditions, while the acceleration of the motor in general and the roll acceleration of the vehicle body especially during cornering maneuvers can be reduced significantly.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-30T12:33:23Z
      DOI: 10.1177/09544070231163925
       
  • Path tracking control of unmanned ground vehicles considering the signal
           time delay

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      Authors: Guoxing Bai, Yu Meng, Li Liu, Guodong Wang, Jianxiu Huang, Haoqing Zheng
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Research on path tracking control of unmanned ground vehicles based on control methods such as model predictive control (MPC) is gradually prosperous. However, the problem caused by the signal time delay has not been taken seriously. It is found that the iterative mechanism of MPC is beneficial for solving this problem, and proposed a solution based on this mechanism. The principle of this solution is to use the control inputs of previous control periods as the inputs of the iteration periods of the prediction model corresponding to the signal time delay. So that the start moment of the iteration period where the first value of the control input sequence of the current control period is located can correspond to the moment when the control input arrives at the vehicle precisely. Based on this solution, a nonlinear MPC (NMPC) controller is designed and verified by co-simulation with MATLAB and Carsim. The simulation results show that the proposed controller can complete the path tracking control in the system with the signal time delay which the traditional NMPC controller and Stanley controller fail, and has high accuracy and real-time performance. In all simulation results, the absolute value of the displacement error does not exceed 0.2622 m, the absolute value of the heading error does not exceed 0.0909 rad, and the solution cost in each control period does not exceed 13 ms. Furthermore, it is also confirmed that the performance of this solution is superior to other solutions dealing with signal time delay.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-28T12:09:09Z
      DOI: 10.1177/09544070231163348
       
  • Study on interior noise control of minibus based on structural acoustic
           radiation

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      Authors: Shenghao Xiao, Jie He, Gang Xu, Yumei Li, Yunlong San, Si Cheng
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Aiming at the problem of excessive low-frequency noise inside a minibus, the interior noise control scheme was studied to improve the NVH (Noise, Vibration, and Harshness) performance of the vehicle based on the characteristics of the structural acoustic radiation. With acoustic contribution as the evaluation index, the ability of the structure to radiate noise to the vehicle was studied from the perspective of modal participation and panel contribution. In this study, the legacy finite element model of the vehicle was firstly established, and the model was validated through the modal test of the BIW (Body in White), and the noise transfer function analysis was carried out to identify the critical frequency points. Furthermore, the improved super element method (SEM) was used to establish the super element simulation model of the vehicle, the simulation analysis of the modal contribution and panel contribution was carried out for the critical frequency points, and the panels that provide the main contribution were determined. In addition, a single-factor experimental study was carried out on the position of the critical panel by using the dynamic vibration absorbers with different performance parameters, so as to verify the accuracy of the simulation results of the panel acoustic contribution for the critical frequency. Finally, the structural optimization schemes of the critical panels were designed and verified by experiments. It was indicated that optimizing the acoustic radiation characteristics of the structure by improving the body panel structure to reduce interior noise was feasible.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-28T12:05:50Z
      DOI: 10.1177/09544070231163346
       
  • Trajectory tracking control considering the transmission backlash of the
           dual-motor autonomous steering system

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      Authors: Zhongwei Wu, Xing Xu, Ju Xie, Zhenyu Liu, Shenguang He
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In order to solve the tracking error caused by transmission backlash in the dual-motor autonomous steering system, and thus improve the trajectory tracking accuracy of autonomous vehicles, a novel steering control strategy combining sliding model control (SMC) with variable weights and linear quadratic regulator (LQR) is proposed in this paper. Firstly, the vehicle dynamics model is built and the steering system model with contact and backlash modes is established by combining it with the simplified gear backlash system. Secondly, the front wheel angle control based on SMC is designed and the weights of contact mode and backlash mode are optimized by Particle Swarm Optimization (PSO) algorithm. Finally, the results of simulation under typical conditions show that the proposed strategy has better accuracy of angle tracking and stronger adaptability to the change of system load. Furthermore, it is also proved by simulation and Hardware-in-Loop (HiL) test under different trajectory tracking conditions that the LQR controller with proposed strategy has better accuracy of trajectory tracking for autonomous vehicles.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-28T11:56:59Z
      DOI: 10.1177/09544070231161845
       
  • Oil jets piston cooling: A numerical methodology for the estimation of
           heat transfer coefficients and optimization of the piston temperature
           field through a genetic algorithm

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      Authors: Fabio Renso, Matteo Giacopini, Saverio Giulio Barbieri, Valerio Mangeruga
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      High-efficiency internal combustion engines need specific methodologies to be developed for the design improvement of the components. Predicting and reducing the thermal loadings on the parts are critical tasks to be addressed. This contribution focuses on the thermal management of the piston through oil jets. The operating temperature of the piston deeply affects its thermo-mechanical behavior, thus possibly jeopardizing the structural integrity of the component. The design of piston cooling jets is usually addressed through Computational Fluid Dynamics, which can guarantee accurate results, usually at a high computational cost. In this contribution, a faster tool is derived to grasp the effect of the cooling jets on the temperature of the piston. Empirical correlations are applied to predict the instantaneous heat transfer coefficients on the piston. The reciprocating motion of the piston is considered since it affects the interaction between the surface and the oil jets. Instantaneous coefficients are cycle-averaged and used to estimate the temperature of the piston through a Finite Element thermal analysis. Finally, an optimization code is developed to find the best jet configuration capable to minimize the temperature of the piston. This methodology is a powerful tool to select the optimal oil jet nozzles for piston cooling.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-27T09:41:37Z
      DOI: 10.1177/09544070231161909
       
  • Crash topology optimization for front-end safety parts of battery electric
           vehicle using an improved equivalent static loads method

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      Authors: Chun Ren, Xusheng Liu, Xuefeng Yang, Tianfei Ma
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Crash topology optimization is a typical nonlinear dynamic response structural topology optimization problem, which is one of the most difficult problem in the structural design field. The equivalent static load method (ESLM) provides a well-defined pattern to solve such difficult problems, which can convert a nonlinear dynamic response optimization into multi-load steps optimization problem with the equivalent static loads (ESLs). However, due to the large deformation in the crash condition and nodal characteristics of the ESLs, it is hard to solve the crash topology optimization directly using the standard ESLM. To expand the application scope of the ESLM, an improved ESLs calculation method is proposed by using the model order reduction method and energy principle, which only acting on some nodes and can be scaled adaptively. Correspondingly, to enrich the connotation of topology optimization, a crash topology optimization method is proposed by using the improved ESLs, which can solve the numerical problems in the design domain by guaranteeing the topology optimization with the improved ESLs perform in the linear rang. First, the principle of the standard ESLM is introduced, and corresponding problems and deficiencies in solving the crash topology optimization are summarized. Then, to solve the above problems, the improved ESLs calculation method is proposed. Meanwhile, the corresponding crash topology strategy is proposed based on the improved ESLs. Finally, to verify the effectiveness and engineering application value of the proposed crash topology optimization method, a test-verified frontal crash simulation model of the BEV front-end is established, and their safety parts are redesigned by using the proposed method. The results show that, the proposed method can effectively solve the crash topology optimization of thin-walled structures under large deformation crash condition. This method also provides a new idea and practical method for the crashworthiness and lightweight design of automobile structures.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-25T11:46:42Z
      DOI: 10.1177/09544070231162137
       
  • Cooperative adaptive cruise control system for electric vehicles through a
           predictive deep reinforcement learning approach

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      Authors: Iman Tahbaz-zadeh Moghaddam, Moosa Ayati, Amir Taghavipour
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In this paper, a predictive deep reinforcement learning-based control algorithm is introduced for the cooperative adaptive cruise control (CACC) system. The proposed control algorithm achieves an optimal response in the interaction of the host vehicle with the leading vehicles. For this purpose, at first, a new algorithm based on deep neural networks is proposed for modeling and predicting the driving behavior of the leading vehicle, according to the traffic behavior of its surrounding vehicles. Then, the outputs of the predictive model are used as additional states for the upper-level controller of the CACC system, which is designed based on a deep reinforcement learning approach. Therefore, the proposed controller uses conventional states such as relative distance and speed of the host vehicle along with the leading vehicles and employs the speed profile of the leading vehicle in the future time horizons to train the reinforcement learning agent. Thus, the upper-level controller learning process is improved. In addition, for regulating the lower-level controller of CACC system against parametric uncertainties in electric vehicle dynamics, a deep reinforcement learning-based controller is proposed, which can be retuned according to the real-time estimated parameters of vehicle mass and road grade. Simulation results represent the promising performance of the proposed control algorithm for maintaining a balance between travel safety, passenger comfort, and reducing vehicle energy consumption.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-25T11:40:25Z
      DOI: 10.1177/09544070231160304
       
  • A novel semi-active suspension algorithm based on a high-precision
           frequency selector

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      Authors: Xiaotian Shi, He Li, Ke Fu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      This study proposes a novel semi-active suspension control algorithm based on a high-precision frequency selector. The algorithm focuses on the phenomenon of redundant switching in frequency domain judgment. Furthermore, the working principle of realizing high-precision selection is explained. The behavior of window sample number N is analyzed theoretically, and the gray prediction theory is used, together with a formerly sampled signal, to predict and obtain advanced output. This can compromise time delay in the control strategy and improve the accuracy of the selector. Using the combined sky-hook and acceleration-driven damper control algorithm and the MIX algorithm as the benchmark, the improved frequency selector is verified under sweep road environments. The results demonstrate that the improved algorithm significantly reduces the number of switches that occur while driving the vehicle, without deteriorating the comfort, thus improving the energy efficiency and service life of the damper.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-25T11:37:05Z
      DOI: 10.1177/09544070231163357
       
  • Evaluation of autonomous emergency braking by using a theoretical formula
           and dual cameras

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      Authors: Bong-Ju Kim, Seon-Bong Lee
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      According to data gathered by the Korean National Police Agency, 1,028,777 vehicle-to-vehicle traffic accidents and 125,597 vehicle-to-pedestrian traffic accidents occurred in 2020. To decrease the occurrence possibility of traffic accidents, advanced driver-assistance system (ADAS), which provides assistance in regions that drivers do not recognize, have attracted increasing interest. Among the representative functions of ADAS, autonomous emergency braking (AEB) is a valuable system for accident prevention and mitigation. In this study, to evaluate AEB by using dual cameras, actual vehicle tests were conducted. In addition, the theoretically calculated values, results obtained using dual cameras, and results obtained using measuring instruments were compared and analyzed. The result values using the proposed theoretical formula and those of the actual vehicle test using the measurement instruments were compared and analyzed. The minimum and maximum error rates were 0.11% and 4.45%, respectively. For results obtained using dual cameras and measurement instruments, the minimum and maximum error rates were 1.80% and 8.89%, respectively. In the development stage of ADAS especially when developing AEB system, the use of the theoretical formula and dual cameras can decrease the cost burden compared to that associated with testing.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-25T11:35:04Z
      DOI: 10.1177/09544070231163204
       
  • Numerical and experimental investigation of irreversible energy losses in
           a two-stage radial turbine under asymmetric inflow conditions

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      Authors: Xuekang Chen, Xin Shi, Chenxing Hu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In a two-stage turbocharger, the coupling between stages and the structure of the inter-stage duct may lead to severe flow distortions, which have a destructive impact on turbine performance. In this paper, the aerodynamics and energy loss mechanisms of two-stage turbines matched with a V-6 diesel engine are experimentally and numerically investigated. To reveal the formation mechanism of the asymmetric inter-stage flow, the vortex transportation in the high-pressure turbine is first analyzed. Entropy generation analysis is applied to quantify the irreversible losses while considering the coupling influence of the asymmetric inflow conditions, and two types of curved inter-stage ducts are studied. The sources of the dominant irreversible losses are revealed and origin of the corresponding energy loss is localized. The results show that the entropy generation rates associated with viscous dissipation, turbulent dissipation, and heat conduction account for about 30% each in the low-pressure turbine. Compared to uniform inflow conditions, the entropy generation rates increase by an average of 43.8%, 196.9%, and 19.2%, respectively under asymmetric inflow conditions. The pivotal turbulent dissipation is primarily concentrated in the inter-stage duct, the impeller inlet, and the volute tongue. The peak value for the difference in the cumulative entropy generation rates from turbulent dissipation is mainly caused by the mixing of the leakage vortex and the separation flow. The novelty of the present study lies in revealing the source of irreversible losses in two-stage turbines, which may provide a fundamental basis for the optimal design of a two-stage turbocharger.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-25T11:33:25Z
      DOI: 10.1177/09544070231162651
       
  • A novel numerical method for quantifying the combined effect of tire on
           13-degree impact test of automotive wheels made of lightweight materials

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      Authors: Yue Zhang, Yingchun Shan, Xiandong Liu, Tian He
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      One of the technical challenges encountered for automobile wheels made of lightweight materials is whether they can successfully pass the 13-degree impact test. When optimizing the wheel impact resistance through finite element method, the combined effect induced by the tire on this performance can be fully included by introducing the tire model, whereas its strong nonlinear characteristics lead to high computational cost and convergence difficulty. Therefore, to introduce the quantification coefficient for combined effect instead of tire model into the impact simulation model can effectively address above problems. However, the inaccurate quantification coefficient leads to the deviation in the evaluation of wheel impact resistance, which may directly affect the optimization design results. Aiming at these problems, a novel numerical method combining the energy reduction and energy-scaling coefficients is proposed. Firstly, an equivalent simulation model of wheel impact test excluding the tire is obtained by calculating and including the energy reduction coefficient. Then, an adaptive energy-scaling coefficient is constructed and introduced to ensure that the wheel strain status remains unchanged. Finally, the effectiveness and practicability of the proposed method are demonstrated by investigating two types of wheels. The results show that the proposed method can serve as an efficient tool during optimizing the impact resistance, not only improving the computational efficiency and convergence by excluding the tire model, but also accurately evaluating the wheel impact performance by including the combined effect.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-25T11:31:05Z
      DOI: 10.1177/09544070231162142
       
  • Predicting vehicle trajectory via combination of model-based and
           data-driven methods using Kalman filter

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      Authors: Bowei Zhang, Weiguang Yu, Yifan Jia, Jin Huang, Diange Yang, Zhihua Zhong
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Predicting future trajectories of surrounding vehicles accurately benefits the decision-making and motion-planning of autonomous vehicles (AVs). Physical-model-based prediction methods are generally accurate in short horizon prediction, but often fail in long-horizon prediction owing to the simplicity of the models and the complexity of the environment. Data-driven prediction methods can achieve promising performance in complex traffic scenarios and long-horizon prediction tasks. However, they might not be reliable on some occasions compared with model-based approaches, mainly owing to their uncertainty, poor interpretability and unsatisfying ability to learn the physical constraints of vehicles. In this paper, a novel cooperative vehicle trajectory prediction strategy exploiting the advantages of the two categories of prediction methods is proposed. The prediction results of the data-driven and kinematic models together with their uncertainties are described by the bivariate Gaussian model, and subsequently combined with an innovatively designed Kalman filter. The fusion strategy provides both physical and environmental constraints on the two types of methods for better prediction performance in both short and long horizons. Experiments applying different data-driven methods were carried out on the public BEV High-D dataset, as well as our specially-collected first-point-of-view highway dataset. The results indicate that the proposed method outperforms both the sub-models adopted in terms of prediction accuracy.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-25T11:27:45Z
      DOI: 10.1177/09544070231161846
       
  • Identification, reproduction, and control of vehicle roll vibration

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      Authors: Hongnan Wang, Bao Zhang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The human body is extremely sensitive to roll vibration, which is also an important indicator for evaluating vehicle comfort. In order to improve the ability of anti-roll vibration of vehicles, the methods of mathematical modeling, dynamic simulation, and vibration test are used in this paper. The generation mechanism, dynamic change law, and key influencing factors of the roll vibration are analyzed. The analysis results include: the dynamic simulation results are in good agreement with the test results, and the use of the simulation model is beneficial to the analysis and control of the roll vibration; the roll vibration is caused by the relative dynamic deformation of the left and right suspensions, and the larger the relative deformation, the more obvious the roll vibration; the optimization of the position and damping of the shock absorber is conducive to the control of roll vibration, which greatly improves the comfort of the vehicle. The research results provide theoretical basis and reference for grasping the characteristics of the roll vibration and vibration reduction design.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-22T10:19:08Z
      DOI: 10.1177/09544070231161904
       
  • Multi-objective optimization of two-stroke compression release braking
           performance of a heavy-duty engine based on non-dominated sorting genetic
           algorithm II (NSGA II)

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      Authors: Yang Wang, Dongsheng Dong, Pingshu Ge, Tao Zhang, Heng Zhang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Traditional heavy-duty vehicle service brakes use the friction method to realize vehicle deceleration, which means that longer-term use of the service brake will lead to overheating. It will make the braking capacity significantly reduced, at the same time, the service brake system also will wear much faster. Engine brake has been developed continuously in recent decades since it has the advantages of small install space and weight, no attenuation of braking power, rapid response, and endurance braking. However, the complex structure and large valve load of the valve train are the main obstacles to the widespread use of two-stroke compression release braking. Two-stroke compression release braking power is the effective indicator of the braking capacity and the maximum cylinder pressure (Pmax) can reflect the load of the valve train, therefore, the braking power and Pmax need to be optimized at the same time. In this paper, the multi-objective non-dominated sorting genetic algorithm II (NSGA II) was introduced to optimize the two-stroke compression release braking performance and it was compared with the orthogonal design method. The results indicated that the braking power and Pmax of optimal solution 1 by NSGA II achieved −395.64 kW and 59.37 bar, which were 1.17% and 2.78% improved than that of orthogonal analysis, respectively. In addition, the calculation process shows that NSGA II provides a more comprehensive and reliable method to optimize the valve parameters of the two-stroke compression release brake.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-22T10:14:48Z
      DOI: 10.1177/09544070231161403
       
  • MOP-SLAM: A real time SLAM system based on multi-head optical flow
           estimation network

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      Authors: Yuxiang Chong, Xiaoci Huang, Zhiyong Dai, Yan Zhang, Zezheng Lv, Yaozhong Liang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      SLAM (simultaneous localization and mapping) is becoming a significant technology in driverless vehicles nowadays. Sometimes the optical flow method can be used to track feature points to reduce the amount of calculation. But the traditional optical flow method is based on the assumption that the luminosity will not change and has high requirements for the environment. Therefore, an optical flow calculation method based on neural network called Optical-Net is proposed in this paper to match and track feature and corner points. We use the multi-head attention module to extract and fuse the features of different scales. The training results show that the Optical-Net designed in this study effectively improves the robustness and accuracy of optical flow estimation when the object has large displacement and small displacement. Meanwhile, to address the problem of reduced matching accuracy during video input due to dynamic blurring, a video dynamic deblurring algorithm based on the one-dimensional Wineman filter is adopted to preprocess the input video. Finally, we replaced the tracking thread in traditional SLAM. The performance of the improved algorithm is verified by experiments on our own driverless car.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-22T10:09:47Z
      DOI: 10.1177/09544070231161198
       
  • Research on anti-rollover warning control of heavy dump truck lifting
           based on sliding mode-robust control

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      Authors: Zhongcheng Fu, Mingmao Hu, Qinghe Guo, Zhigang Jiang, Dong Guo, Ziwen Liao
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In order to improve the rollover stability of heavy dump trucks during lifting and unloading under special circumstances and prevent heavy dump trucks from overturning, a sliding mode-robust control based on anti-rollover early warning control method for heavy dump trucks lifting and unloading was proposed. A four-degree-freedom heavy dump truck lifting and unloading roll dynamic model was established, and the accuracy of the model was verified in the MATLAB/Simulink simulation environment. The controller was designed by combining sliding mode robust control based on HJI theory and active suspension control. The ratio of the gravity carried by the wheel with the lighter bearing capacity to the total gravity of the heavy dump truck was used as the evaluation index for rollover warning. Under two different simulation conditions, compared with conventional sliding mode control and no control, the rollover evaluation index and roll angles were analyzed under three control methods. The results showed that the anti-rollover early warning control method for lifting and unloading of heavy dump trucks proposed in this paper had better anti-rollover capability and better stability.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-22T09:58:48Z
      DOI: 10.1177/09544070231160901
       
  • A novel design methodology for fixed-shaft hybrid powertrain with a
           single-motor

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      Authors: Tao Deng, Xin Zhou, Ke Zhao
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Hybrid power configuration has two kinds of power sources, how to design the configuration to couple the energy of the two power sources is an important part of the development of hybrid power technology. In the systematic design scheme of hybrid power, most scholars focus on the design of planetary gear hybrid power configuration, but lack of systematic design scheme of fixed-shaft hybrid power configuration. In this paper, based on the equivalent tree graph method, the fixed-shaft hybrid configuration is transformed into the corresponding tree graph representation, and all possible configurations are generated by the combination of the trunk, branches and leaves. Add the corresponding design constraints, use Matlab to realize automatic generation and screening, and finally obtain the required configuration after specification. The configuration is verified in the Simulink & Amesim co-simulation environment. The results show that the proposed single-motor fixed-shaft hybrid power configuration has certain advantages in economy compared with the traditional P2 and P3 configurations, and its dynamic performance is the same as that of P2 configurations and superior to P3 configurations.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-16T10:14:46Z
      DOI: 10.1177/09544070231160205
       
  • Backstepping sliding mode control for an active hydraulically
           interconnected suspension

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      Authors: Tong Chen, Minyi Zheng, Nong Zhang, Liang Luo, Pengfei Liu, Yaohua Guo
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      This paper presents a backstepping sliding mode control (BSMC) method for an active anti-roll hydraulically interconnected suspension (HIS) system. The proposed control strategy enables the active HIS system tracking desired anti-roll moment within the working area. Based on the tracking error, the BSMC controller calculates the flowrate of the control cylinder. This flowrate successively changes the pressure in the accumulators and cylinder chambers, and finally determines the output anti-roll moment of the HIS. The HIS system parameters uncertainty and the system’s nonlinear characteristic are both considered in the proposed BSMC controller. To comprehensively design and validate the proposed control method, a 4-DOF half car model and a corresponding nonlinear active anti-roll HIS model are firstly established. Next, a linear quadratic regulator (LQR) upper layer controller is designed to optimize the vehicle’s roll motion, and the result of the LQR controller is set as a tracking target. Thereafter, the proposed BSMC bottom layer controller is designed to track the target moment. Finally, numerical simulation and experiments on the test bench are conducted to validate the proposed control method. The simulation and bench test results indicate that the proposed active HIS performs well in tracking target and tolerating disturbance. The proposed active HIS expands about additional ±1000 N/m dynamic anti-roll moment compared to a passive HIS at each roll angle, and the response time is less than 70 ms. The field test results show that the active HIS with proposed control method improves anti-roll property compared with a passive HIS by 23.3% in the double lane change test.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-15T01:08:24Z
      DOI: 10.1177/09544070231158436
       
  • A bi-level control framework with temperature rise inference and
           intelligent decision-making longitudinal control on downgrade hydrodynamic
           braking process

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      Authors: Xiuqi Chen, Wei Wei, Tianlang Tao, Naipeng Hu, Yuze Wang, Qingdong Yan
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Temperature rise is a salient characteristic of the braking device of heavy-duty vehicles (HDVs) during long downhill braking. The temperature-independent effect on braking performance is an inevitable challenge for the longitudinal controller, which also causes the overheating of mechanical or hydrodynamic braking devices and may bring about brake failures for heavy-duty vehicles. To this end, a universal Bi-level control framework combining a temperature hierarchy system performance prediction method and a deep reinforcement learning (DRL)-based controller is proposed for long downhill braking of heavy-duty vehicles. Firstly, the temperature-independent characteristic is clustered to predict the braking performance under various rotating speeds. Secondly, a data-driven model for temperature rising is built for the long-time braking thermal prediction and estimates the safety remaining braking time using the auxiliary braking. Thirdly, a temperature-hierarchy environmental perceptive control framework with Double Deep Q Network (DDQN) algorithm is exploited to achieve the target speed tracking accuracy. Thermal safety is ensured with the application of fast calculating for the thermal rising, along with the effective estimation of remaining braking performance on endurance braking. The proposed Bi-level longitudinal controller is compared with the average-temperature strategy and the classic PID strategy to validate its superiority in terms of speed-tracking accuracy on robust conditions. The simulation results show that the proposed strategy improves the speed tracking accuracy by 37.31% on constant slope conditions and 68.11% on varying slope conditions compared with the classic PID strategy. Furthermore, a processor-in-the-loop test experiment verifies its real-time application.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-13T08:38:40Z
      DOI: 10.1177/09544070231156951
       
  • Optimal design of continuously inflated airbag for 12-year-old child
           occupants with various sitting postures

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      Authors: Liang Hong, Peng Liu, Ruhai Ge
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Owing to the lively nature, children often use a variety of non-standard sitting postures when riding school buses. Current restraint systems in school buses and traditional airbags cannot effectively protect the child occupants with the non-standard sitting postures in frontal collisions. A prototype design of a new continuously inflated airbag is proposed to increase the safety of child occupants. The aim of this study is to determine the injury thresholds of 12-year-old children using the dimensional analysis method, and under the eight mixed conditions, to propose an optimal design of a continuously inflated airbag. First, a simulation model of the restraint system is developed and validated by the experimental test conducted according to ECE R80/GB24406. Then, a coupling model of the restraint system and continuously inflated airbag is built. Second, a standard and three non-standard sitting postures of 12-year-old child occupants and the two crash pulses of school buses are combined to form the eight mixed conditions. Finally, the main design parameters of the continuously inflated airbag are optimized using the non-dominated sorting genetic algorithm III and entropy weight method. A continuously inflated airbag with the optimal configuration can significantly reduce the injuries to the 12-year-old child occupants. Under the original crash pulse, the optimized airbag can provide the best protections for the occupant head under the forward-leaning sitting posture and the occupant femurs under the slouched sitting posture, respectively. Under the higher-speed crash pulse, the protective effect on the occupant head under the standard sitting posture is better than that under the right-leaning sitting posture.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-11T05:51:08Z
      DOI: 10.1177/09544070231158734
       
  • Longitudinal and lateral coupling vehicle stability controller designed
           based on piecewise T-S fuzzy model

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      Authors: Zhicheng Chen, Bing Zhu, Jian Zhao, Jian Wu, Hao Guan, Hualin Xu, Zhipeng Liu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Due to tire force coupling and load transfer coupling during the stability control process, the vehicle longitudinal and lateral dynamics shows particularly obvious nonlinear coupling characteristics, which will deteriorate the performance of the stability controller. This paper proposes a Vehicle Stability Controller considering the vehicle longitudinal and lateral coupling characteristics. First, a piecewise guidance method, including the Adaptive Linear Regression Algorithm and Dimensionless Performance Evaluation Weighting Function, is developed to ensure the Takagi-Sugeno fuzzy model piecewise approaches the nonlinear characteristics of the original system and obtains the multiple linear fuzzy subsystems. Then, an H∞ robust controller with dynamic output feedback is used in each fuzzy subsystem based on the identification result of the driving intention, and the Linear Matrix Inequality is applied to obtain the controller gains. Subsequently, the Parallel Distributed Compensation architecture is adopted to integrate the outputs of all fuzzy subsystems, and vehicle stability controller is realized by using a rule-based control distribution strategy. The proposed controller is evaluated by simulations and hardware in the loop tests, and the results demonstrate satisfactory longitudinal following ability and lateral stability.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-09T12:25:37Z
      DOI: 10.1177/09544070231157134
       
  • A high-speed human-like collision avoidance controller based on a neural
           network under different road adhesion coefficients

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      Authors: Qianxi Pan, Bing Zhou, Xiaojian Wu, Kangqiang Zheng
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Safety and stability have been two main considerations in the field of collision avoidance. However, if the response of a vehicle to avoid collision does not conform to the habits of a human driver, it can cause tension and discomfort to the driver, or even worse, misunderstanding between the driver and an automatic driving system can occur, leading to a traffic accident. Therefore, a driver’s reaction characteristics should be considered, and the reaction expected by the driver should be satisfied as much as possible. This study proposes a human-like collision avoidance model based on a neural network under emergency conditions. The vehicle response data collected from experienced drivers in the collision-avoidance stage via driving simulators are used to train the neural network model. A front-wheel angle controller is developed to track the output of the human-like neural network model. Moreover, the stability region of a vehicle is obtained by the K-means method. Further, a differential braking controller is designed to ensure the safety and stability of the vehicle. The simulation results show that the proposed human-like collision avoidance controller not only meets the safety and stability requirements of collision avoidance but can also ensure good driving comfort for human drivers.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-09T02:09:46Z
      DOI: 10.1177/09544070231158748
       
  • Constraint performance slip ratio control for vehicles with distributed
           electrohydraulic brake-by-wire system

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      Authors: Yuan Ji, Junzhi Zhang, Junfeng Zhang, Chengkun He, Xiaohui Hou, Jinheng Han
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Slip ratio control of current passenger vehicles is achieved by the traditional hydraulic distributed unit through its pump-valve structure, such as the antilock brake system module. This type of hardware largely limits the essential braking pressure regulating ability due to the pump’s jittering backpressure and valves’ poor controllability and further deteriorates the slip ratio control performance. This study proposes a novel electrohydraulic brake-by-wire system based on distributed boosters (Dbooster) as new slip ratio regulating actuators. The Dbooster’s dynamics are modeled and combined with slip braking dynamics into an integrated slip ratio control scheme. Based on this, a finite-time prescribed performance control method with a finite-time disturbance observer is designed to achieve constraint slip ratio regulating performance. Validations are conducted in simulation and hardware-in-the-loop tests. Furthermore, the results show that this study provides a practical solution for more accurate slip ratio regulation.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-04T09:33:12Z
      DOI: 10.1177/09544070231157154
       
  • Experimental investigation on the R1234yf air conditioning system with a
           battery cooling loop under realistic conditions of electric vehicles

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      Authors: Bentao Guo, Lanping Zhao, Jian Zhou, Xudong Sun, Zhigang Yang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The air-conditioning system of an electrical vehicle (EV) with a cooling loop for battery was experimentally investigated at medium to high load conditions, using R1234yf as refrigerant. Optimal filling rates of R1234yf and R134a were first determined as 975 g with the battery cooling loop closed. Then, the system performance regarding the two refrigerants with optimal charges was compared with various chiller thermal loads at maximum cabin cooling capacity condition as well as nine high load conditions. It was found that using R1234yf as the alternative of R134a, the HVAC cooling capacity, the power consumption of the compressor and the coefficient of performance (COP) decreased by 23.6%, 10.5%, and 8.1%, respectively, at maximum cooling capacity condition with a chiller load of 1.5 kW. At high load conditions with various chiller thermal loads, the reductions of HVAC cooling capacity and power consumption were 8.2%–29.8% and 3.2%–19%, respectively, resulting in a decrease in COP of 1%–16.3%. Thirdly, it was presented that, for R1234yf, at high vehicle speed conditions with the TXVs as original setting, the outlet air temperature of the HVAC box increased about 2.4°C, with the power consumption increased by 17.3%, if the chiller thermal load was increased from 0 to 2.5 kW. Other main conclusion included that, at idle condition, for the R1234yf system with the chiller loop on, the outlet temperature of the HVAC box and COP decreased by 2.7°C and 37.1%, respectively, when the compressor speed increased from 4000 to 7000 rpm.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-04T09:24:50Z
      DOI: 10.1177/09544070231156953
       
  • Comparative study of ignition characteristics and engine performance of
           RP-3 kerosene and diesel under compression ignition condition

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      Authors: Jianping Wang, Qiankun Zhang, Yaoyuan Zhang, Liang Yu, Dezhi Zhou, Xingcai Lu, Yong Qian
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      This paper aims to explore the spontaneous combustion characteristics and engine performance of kerosene under traditional compression ignition mode, providing a reference for further optimizing the performance of kerosene compression ignition engines and the application of advanced combustion mode. The ignition visualization tests of kerosene under marine and vehicle engine conditions are carried out, and the characteristics under 0.3 mm nozzle diameter are compared with that of diesel. Then, the engine performance of the two fuels under medium load and ultra-high injection pressures is compared. The experimental results show that the ignition and combustion characteristics of kerosene and diesel are very similar, indicating that kerosene has a strong universality in diesel engine application. The long ignition delay time of kerosene leads to its lagging combustion and heat release. Compared with diesel, kerosene has lower CO, particulate emissions and indicated thermal efficiency, while higher HC and NOx emissions. The emission characteristics of kerosene RP-3 are different from previous studies, especially under ultra-high injection pressure. The combustion process and engine emissions of kerosene may be optimized with advanced combustion models and strategies.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-04T09:11:52Z
      DOI: 10.1177/09544070221146349
       
  • An innovative method for scene recognition and target tracking for
           adaptive cruise control in complex traffic environment

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      Authors: Litong Zhang, Congzhi Liu, Baichao Wang, Xiang Chen
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The adaptive cruise control (ACC) system as a typical advanced driver assistant system (ADAS) has been commercially application in automotive industry for decades. An innovative method is proposed in this paper for scene recognition and target tracking for ACC application in some complex traffic environment. Firstly, a multi-sensor fusion method is established to estimate the curvature integrated by the quadratic programing (QP)-based lane boundaries detection, vehicle dynamics of lateral motion, and an improved Kalman filter (IKF) to introduce more measurement information into the feedback correction process. Then, the closet in-path vehicle (CIPV) can be selected according to the statistical distance between the tracked targets and the predicted driving path of ego vehicle. To distinguish the lane changing and curve driving behaviors, the trajectory models of obstacles are established as an ellipsoid domain equation and transformed into a regression model, which is recast as a standardized QP problem. Hence, the behaviors and scenes can be recognized effectively. To restrain the disturbance and improve the accuracy and robustness of target tracking, an [math]-based switched tracking method is proposed by combining of the low pass filter (LPF) and [math] theory. Finally, an accurate and robust tracker is provided for the CIPV by incorporating with four steps: IKF-based curvature fusion estimation, CIPV selection, QP-based scene recognition, and the [math]-based observer. Moreover, two real car experiments are adopted and the results verify the effectiveness and real-time performance of the proposed method.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-03T11:08:38Z
      DOI: 10.1177/09544070231156956
       
  • Biodiesel composition based machine learning approaches to predict engine
           fuel properties

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      Authors: Kiran Raj Bukkarapu, Anand Krishnasamy
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Recently data-driven machine learning approaches received considerable attention in several applications, including developing models to predict engine fuel properties of biodiesel. Multilinear regression (MLR) is the most straightforward method among the available approaches in the literature to predict biodiesel properties. However, a nonlinear correlation between biodiesel composition and properties cannot be modeled using the MLR approach, resulting in poor predictability. Artificial neural network (ANN), the most explored nonlinear regression approach to predict biodiesel properties, is prone to poor reproducibility. Support Vector Machine (SVM) regression is a machine learning approach that can be applied to develop biodiesel property prediction models whose favorable features include nonlinear data modeling. Models are developed to correlate biodiesel composition with calorific value, viscosity, and cetane number in the present work using ANN and SVM regression. Seventy biodiesels with varying compositions are used for calibrating the models and 30 other biodiesels for validation. Both the nonlinear regression approaches perform well in predicting the biodiesel properties, among which SVM results in better prediction than ANN. SVM resulted in models with a MAPE of 0.26%, 1.07%, and 1.69%, respectively, for calorific value, viscosity and cetane number of biodiesels which are considerably lower than those predicted using the literature models.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-03-03T01:51:17Z
      DOI: 10.1177/09544070231158240
       
  • Research on the braking energy reuse management strategy of hybrid
           electric mining trucks based on motor load rate

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      Authors: Yilin Wang, Weiwei Yang, Wenming Zhang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The braking energy recovery and reuse technology are significant to the energy-saving and emission reduction of hybrid mining dump trucks. Therefore, this paper proposes a technical scheme to increase the speed of the heavy-load uphill section by using the light overload of the motor. By constructing the vehicle dynamics model of the mining dump truck and the electric drive system component efficiency and engine energy consumption model and taking the “feedback braking energy-saving coefficient” as the evaluation index, the electric motors of each slope section under the rule-based energy management strategy are obtained. Then, the dynamic programing algorithm is used to optimize the selection of the motor load rate on the slope section. The results show that: on the premise of ensuring the dynamic performance of the vehicle, maximizing the use of the braking energy can shorten the driving time by 57.8 s and reduce the engine energy consumption 18.63 kWh, accounting for 8.56% of the engine energy consumption of the entire heavy-load uphill section. This paper provides a theoretical reference for the energy-saving research on the efficient reuse of braking energy of mining dump trucks on slopes.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-02-21T11:18:25Z
      DOI: 10.1177/09544070231155706
       
  • Synchronous and fault-tolerance control for dual-motor steer-by-wire
           system of commercial vehicle

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      Authors: Guobiao Shi, Pengfei Qiao, Donggang Sang, Shuai Wang, Minghao Song
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In order to meet the high safety requirement of high-level automatic steering mechanism for commercial vehicle, a kind of steer-by-wire (SBW) system with redundant motors is studied in this paper, and the structure principle and control strategy of the system are studied. Commercial vehicles have the characteristics of large steering resistance moment, which is accompanied by impact and vibration during steering, so the synchronous control of dual motors is the key and difficult problem. Based on the circulating ball steering gear for commercial vehicle, dual-motor synchronous control architecture is designed and the dual-motor global-fast-terminal-sliding-mode (nonsingular-GFTSM) synchronous control is formulated. Compared with the sliding-mode control, the simulation results show that the dual-motor actuator based on nonsingular-GFTSM can better realize the synchronous operation in angle, speed and torque. In addition, a real-time motor fault-diagnosis method based on sliding mode observer and a fault-tolerant control strategy based on smooth switching system are designed, which can achieve fast fault-isolation and smooth torque switching in case of actuator failure in dual-motor system. A Hardware-in-the-Loop (HIL) test bench is built to further verify the effectiveness of the synchronous and fault-tolerance control strategy for dual motors.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-02-21T10:58:25Z
      DOI: 10.1177/09544070231154961
       
  • Forward design of the hydraulic system for the two-speed electric drive
           automatic transmission

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      Authors: Huijun Yue, Zhinan Chen, Xiaoxiao Wu, Shuhan Wang, Xi Lu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The two-speed electric drive automatic transmission (2EDAT) is an effective scheme to improve the economy and power performance of electric vehicles. It is significant to carry out forward design, valve body improvement, and oil circuit optimization of the hydraulic system for 2EDAT. In the study, the functional requirement of 2EDAT hydraulic system was firstly analyzed and key parameters were calculated to determine the principle design of the hydraulic system. Then, the simulation model of the hydraulic system was established in the multidisciplinary dynamic simulation platform ITI-SimulationX and the changes in the pressure of the main oil circuit, the clutch oil pressure, and the cooling and lubrication flow in the shift process of the hydraulic system were simulated and analyzed. Furthermore, according to the principle scheme and constraint conditions of the whole machine, the overall layout and the hydraulic valve plate of the hydraulic system were designed and the valve plate and hydraulic system were tested on the bench. The test results of clutch pressure were 5.73%–13.12% lower than the designed value and did not meet the design requirements. Finally, according to test results, the processing defects of the pressure reducing valve were mitigated and the main oil circuit was optimized for another test of the valve plate and the hydraulic system. The test results of clutch pressure were 0.35%–8.60% higher than the designed value and met the design requirements. The results showed that the optimized hydraulic system realized the better control effects on the main oil pressure and clutch oil pressure in the shift process, including the fast and accurate clutch shift response, the sufficient cooling and lubrication flow, and smooth working conditions.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-02-21T10:51:50Z
      DOI: 10.1177/09544070231154953
       
  • Experimental and numerical studies on bending characteristics of woven
           CFRP reinforced aluminum thin-walled automotive structures

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      Authors: Guang Chen, Duo Han, Junyuan Zhang, Guoxi Jing, Xiuxiu Sun
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Metal/composite hybrid thin-walled structure is the most preferential approach to achieve dual contradictive objectives of high crashworthiness and lightweight of auto body. Its collapse with regard to different fiber layup patterns is one of the governing mechanisms of energy dissipation, which is yet to be explored. Especially, the effect of different fiber layup angles and layup sequences on bending collapse, which is one of the most significant performance indicators, has received little attention. To this gap, this study investigates experimentally and numerically the bending characteristics of aluminum/carbon fiber reinforced plastic (Al/CFRP) hybrid structures with different layup angles and layup sequences. To start with, three-point bending tests are carried out on specimens to derive the bending failure behavior and crashworthiness, and the internal section damage is observed by CT scan. Finite element model is then constructed and benchmarked against the test results to be proficient. On this basis, the effects of Al thickness, number of CFRP layers and CFRP wrapping range on the bending performance of hybrid tube are analyzed numerically. The simulation results show that layup angle has greater effect on the bending performance than layup sequence. Increasing Al thickness and the number of CFRP layers can effectively improve the bending resistance of structure, and appropriate partial wrapping of CFRP can increase the specific energy absorption (SEA) by 10.92% compared with that of complete wrapping. The revelation from this study provides sound reference for the crashworthiness design of metal/composite hybrid thin-walled structure.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-02-17T10:52:53Z
      DOI: 10.1177/09544070231154957
       
  • A fast analytical local path planning method with applications in parking
           scenarios

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      Authors: Mostafa Ghajar, Mohsen Alirezaei, Igo Besselink, Henk Nijmeijer
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In this paper an analytical and geometry-based path planning method is proposed that provides non-holonomic and collision free paths for parking maneuvers. The proposed method is straightforward in the sense that it does not require any sampling or exploring of the configuration space, or relies on any optimization process. Furthermore, the calculation is fast enough to be used in real-time applications for guiding the vehicle in parking scenarios. For any pair of start-goal configurations, the planner presents an infinite set of solutions. These paths have minimum number of driving direction changes as this can be more important for a driver than the path length. They may have any curvature lower than or equal to the maximum specified curvature. Simulations show the superiority of the method in local path planning over conventional methods such as hybrid A* and optimization based approaches in terms of computation time and path quality attributes such as the number of motion primitives and the number of direction changes. To compose a complete motion planning system, the proposed local planner is applied along with hybrid A* as global planner and a path tracking controller. The performance of the motion planning system is evaluated by simulating a valet parking scenario. MATLAB/Simulink is used to simulate the system, and a comprehensive vehicle model in CARSIM is used to represent the vehicle. Simulation results shows the capability of the proposed motion planner to implement automated valet parking tasks while respecting the physical limitations of the vehicle subsystems and driving comfort requirements.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-02-14T09:05:46Z
      DOI: 10.1177/09544070231154457
       
  • A three-time-scale dual extended Kalman filtering for parameter and state
           estimation of Li-ion battery

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      Authors: Mengyu Zhu, Kangfeng Qian, Xintian Liu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Estimation of battery state and parameters play an important role in electric vehicle battery management system (BMS). Second-order RC model is applied, the initial parameters of battery model are determined by experiments. Data points of open circuit voltage and state of charge (OCV-SOC) are determined by experiment. Different function forms are used to fit the OCV-SOC discrete points, and the function form with great fitting effect is selected as the OCV-SOC fitting form. Dual extended Kalman filter which is divided into Parameter filter and state filter is applied. Battery state in state filter is a fast-time-varying parameter, The battery model parameters in parameter filter are divided into two parts. the battery model parameters are classified according to the influence of each parameter on the terminal voltage. A longer sampling time is applied to the parameters that have a strong impact on the terminal voltage, and a longest sampling time is applied to the parameters that have a weak impact on the terminal voltage. The time-scale classification method is validated both quantitatively and qualitatively. Compared with the previous methods, the three-time-scale classification method can reduce the number of parameter updates.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-02-13T05:53:23Z
      DOI: 10.1177/09544070231153440
       
  • The prediction of autonomous vehicle occupants’ pre-crash motion during
           emergency braking scenarios

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      Authors: Alexander Diederich, Christophe Bastien, Mike Blundell
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      This research investigates a computational method, which can assist the development of occupants’ passive safety in future autonomous vehicles, more particularly in the definition of head kinematics in rotated seat arrangement during emergency braking. To capture these head motions, the methodology utilised an Active Human Model, whose head kinematics were validated in a previous work in three-point and lap-belt restraint configuration scenarios. A sled model was then built where the seat backrest angle (SBA) and the seat orientation, modelled by rotating the acceleration angle (AA), could be adjusted to represent various ‘living room’ seating conditions. A Design of Experiments study was then performed by varying AA from 0° to 360° in steps of 22.5° and SBA from 20° to 60° in steps of 8°. The responses were subsequently converted into a Reduced Order Model (ROM), which was then successfully validated through a comparison with the kinematic responses predicted with simulations. In terms of simulation time, it was found that the ROM was able to calculate the head kinematics in 3 s instead of the 1.5 h taken using Simcenter Madymo, without compromising predicted responses accuracy. This research has provided a unique method to define head kinematics corridors for seated occupants in autonomous vehicle interiors, including maximum head excursion, head kinematics as a function of time and define for the first time (a) the safe “or’ but not both head envelope within the cabin interior, and (b) capture the seated scenarios where head proximity to airbag systems could be of concern, following emergency braking.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-02-13T05:49:05Z
      DOI: 10.1177/09544070231153262
       
  • Comprehensive CO2 emissions analysis and optimization of plug-in hybrid
           electric vehicles

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      Authors: Daxin Chen, Tao Chen, Yifang Feng
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Fuel and grid have different life-cycle carbon emission intensities, which makes plug-in hybrid electric vehicles (PHEVs) have great low-carbon potential. To reduce carbon emissions during PHEV driving, the energy allocation of PHEV based on carbon intensity is studied. The energy life cycle carbon emissions factors are collected and energy management strategies (EMS) are developed. A power-split PHEV model is established to analyze carbon dioxide (CO2) emissions. Carbon emissions factors calculate the carbon emissions of each power flow. Simulation research is carried out using Tianjin and Yunnan’s energy structure as an example. The equivalent CO2 emission minimum strategy (ECEMS) is established by optimizing the hybrid mode in the Rule-based strategy. Based on ECEMS, the improved particle swarm optimization (PSO) algorithm is used to optimize the rules of hybrid mode switching. As a comparison, the same method but a different goal is used to optimize energy consumption. The results show that the lowest energy consumption does not mean the lowest carbon emission. CO2 emissions in different scenarios are reduced by 7.1%–31.7%, but the energy consumption is increased.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-02-13T05:47:04Z
      DOI: 10.1177/09544070231152519
       
  • Innovative modeling strategy of wind resistance for platoon vehicles based
           on real-time disturbance observation and parameter identification

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      Authors: Jiachen Dong, Qinhe Gao, Jianqiu Li, Jingkang Li, Zunyan Hu, Zhihao Liu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Variable inter-vehicle distances influence significantly the wind resistance of platoon vehicles due to the sheltering of airflow. Accurate air drag estimation is extremely important for platoons in scenarios like energy-oriented driving and high-precision tracking. Most aerodynamic researchers have performed qualitative analysis of wind resistance for equally inter-spaced platoons, while the quantitative description of wind resistance variation with coupled inter-vehicle distances is rare. In addition, data measured through offline wind tunnel experiments, Computational Fluid Dynamics (CFD) simulations, or road tests via fuel consumption calibration for a period of time is unsynchronized, which may be unconvincing for real air drag estimation on road. Aiming at the quick and accurate approximation of platoon wind resistance, this paper proposes a novel and universal modeling strategy combining offline CFD simulation, online air drag observation, and real-time parameter identification. The variation characteristics of air drag with distance of a longitudinal platoon consisting of three homogeneous C-class Notchback cars are analyzed by CFD simulation. With appropriate data processing, a well-designed basis function is summarized. Then a novel wind resistance separation method combining Back-Propagation Neural Network (BPNN) and Extended State Observer (ESO) is proposed. Using the observed data stored in experience memory, the hybrid optimization method via particle swarm optimization (PSO) and gradient descent with momentum (GDM) is employed to identify the model parameters toward high accuracy and global optimality. Results of Hardware-In-the-Loop (HIL) experiment show that the proposed modeling strategy realizes effective real-time observation and accuracy description; the developed approximation model can describe the platoon wind resistance with continuous and coupled inter-vehicle distances, with the RMSE less than 11.4%.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-02-07T12:25:50Z
      DOI: 10.1177/09544070231153213
       
  • Trajectory planning for autonomous vehicle based on window-constrained
           Pearl model

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      Authors: Xiao Lu, Guang Liu, Haiqing Liu, Laxmisha Rai, Haixia Wang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Speed guidance is a significant application in driver assistance system or driverless automated system. Considering the traditional Pearl model-based trajectory planning, this paper proposes an improved method based on window constraints to enhance the rationality at intersection positions. To solve the problem, where the slopes of traditional time-distance Pearl curve at the two boundaries generate relatively low values and which is not in accordance with the actual situation, a new window constraint is used to guide the vehicle passing through the intersection at a high speed. Regarding the new window constraints, together with the maximum speed, tolerating accelerated speed constraints, and traffic signal length constraints, a multi-variable and single objective optimization improved nonlinear programing scheme is applied to obtain the most comfort trajectory of passengers for speed guidance. Simulation results show that, the proposed method presents better performance in traveling time and trajectory smoothness compared with the traditional method under different initial vehicle speeds at upstream intersections and signal offset cases.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-02-06T06:54:00Z
      DOI: 10.1177/09544070231152518
       
  • Markov velocity predictor based on state space optimization and its
           applications in PHEV energy management

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      Authors: Rong Wang, Yanze He, Tinglun Song
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Predictive energy management (PEM) strategy has shown great advantages in improving fuel economy for plug-in hybrid electric vehicles (PHEV). A Markov velocity predictor optimization method and its applications in PHEV energy management is studied in this paper. The initial Markov velocity predictor is constructed using complete driving cycle information and the state space of the Markov velocity predictor is then optimized for specified driving conditions using simulated annealing algorithm (SAA). The practical driving conditions are identified using a multi-feature driving condition recognition unit by using the support vector machine (SVM) method. Based on the driving conditions identified, velocities are predicted using the proposed method and optimized using dynamic programming (DP) algorithm in conjunction with the state of charge (SOC) reference and vehicle state. The energy management strategy derived is then implemented in the vehicle controllers. Comparing with the traditional rule-based energy management strategy, simulation results indicate that the PEM strategy proposed herein can reduce fuel consumption.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-02-06T06:52:25Z
      DOI: 10.1177/09544070231152000
       
  • Sensitivity analysis and multi-objective optimization of the virtual track
           train parameters considering the coupling effect between vehicles

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      Authors: Zhang Jimin, Wang Chengping, Zhou Hechao, Lu Haiying
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      To improve vehicle stability, passenger comfort and road friendliness of the virtual track train (VTT) negotiating curves, a multi-parameter and multi-objective optimization platform combining the VTT dynamics model, Sobal sensitivity analysis, NSGA-II algorithm and [math] optimal selection method is developed. Considering the mutual coupling between vehicles and taking random road roughness as excitation, the VTT dynamics model with 66-DOF is constructed and verified. Design variables and objective functions are defined, and then key design variables are obtained via Sobol sensitivity analysis. The NSGA-II algorithm is used to optimize the key design variables of the VTT, and the [math] optimal selection method is used to select the Pareto solution sets. The results demonstrate that the optimization platform can effectively reduce the number of design variables (from 11 to 6) and improve stability, lateral comfort, vertical comfort and road friendliness, (2.78%, 1.19% and 14.71%, 3.09%, respectively). Also, a multi-parameter and multi-objective optimization platform of the VTT has certain applicability to straight-line conditions and different curve radius conditions. This research provides a feasible solution for the comprehensive performance improvement of the VTT passing through a minor curve. In addition, it also provides a reference for the optimization analysis of multi-marshaling vehicles considering the interaction between vehicles.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-02-06T06:50:23Z
      DOI: 10.1177/09544070231151994
       
  • Fast object detector with center localization confidence based on FCOS for
           environment perception in urban traffic scene

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      Authors: Yue Chen, Ying Shi, Changjun Xie, Chaojun Lin, Qin Hu, Zhuo Chen
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Environment perception on urban roads is one of the most important tasks in Automatic Driving System, because object detection is necessary in identifying and localizing cars and pedestrians. However, the accuracy and inference speed are still far away from satisfying, and the problem of missed detection occurs frequently. To address the problems, this paper first uniformly scales all dimensions of depth, width, and resolution in feature extraction module, and then fuses the semantic information in bidirectional cross-scale connections, which extract more significant features and detect objects of various scales. To decrease the undetected rate of small objects, this paper further introduces an IoU-based center localization confidence, which predicts centerness and the distance between the center of predicted box and the center of the ground-truth box, so that the predicted point approaches the center of an object. The experimental results on Cityscapes show that the proposed detector brings an improvement of 6.5% Bbox mAP and reaches an inference speed of 36.6 FPS. Compared with the other widely-used detectors such as Cascade R-CNN, FCOS, and YOLOX, it has obvious advantages in both precision and real-time performance. With additional ticks, the detection precision can be further improved by 4.4%. The proposed detector can accurately and quickly identify and localize objects, which is beneficial for the safety of self-driving cars.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-02-04T10:38:58Z
      DOI: 10.1177/09544070231153199
       
  • Investigation of tire stiffness and damping coefficients effects on
           automobile suspension system

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      Authors: Hossein Talebi Rostami, Maryam Fallah Najafabadi, Davood Domiri Ganji
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In this paper, we analyzed the vibration of an automobile suspension system. The influence of tire pressure and arc angle, vehicle velocity, and road impact frequency on the tire stiffness and damping coefficient was considered in this analysis. Moreover, an experimental formula for tire damping coefficient based on automobile velocity and impact frequency was proposed. In addition, the effects of the automobile’s mass, mass moment of inertia, unsprung mass, and center of gravity on the amplitude and period of vibration were investigated. The body was considered rigid, and the tires and other unsprung-loaded accessories were particles of a four-degree-of-freedom system. The equations of motions were solved by the analytical Laplace transform method and validated using Runge-Kutta numerical method. Based on outcomes for an initial displace of the front axle, increasing the tire pressure from 0.2 to 0.8 MPa leads to a 40% increase and 70% decrease in front and rear axles, and declining tire arc angle from 50° to 30° increases the maximum displacement of the front axle by 13% and halves the period. Different excitation frequency values (5, 10, 50, and 100 Hz) were applied to the system, which produced a 31%, 8%, and 9% rise in amplitudes. We understood that the tire damping coefficient decreases on a logarithmic scale for an automobile with a speed between 1 and 25 m/s. Furthermore, alternation in mass does not affect body rotation, and the alternation of mass moment of inertia does not influence body displacement significantly.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-02-04T10:37:37Z
      DOI: 10.1177/09544070231151860
       
  • Novel shift process control strategy for two-speed clutchless automatic
           mechanical transmission based on segmented speed regulation

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      Authors: Wang Bing, Yao Mingyao, Wu Jinglai, Hong Xianqian, Zhang Nong
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Battery electric vehicles (BEV) equipped with two-speed automatic mechanical transmission (AMT) have gained increasing popularity owing to advantages of a widened high-efficiency operation zone and system costs. In this study, a combined gear shift control strategy including a segmented speed regulation control and torque recovery control was developed for a two-speed AMT in BEV. The switching point of proportional integral control and sliding mode control during speed regulation process is adaptively optimized to ensure minimization of the shift time, while the maximum vehicle jerk is controlled within a defined range. The effectiveness of proposed control strategy is verified by a test bench. Results show that proposed control strategy can not only ensure the impact degree fluctuates within a predetermined range, but also achieve fast and accurate speed regulation which can reduce the speed regulation time by 17%–33%.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-02-04T10:35:39Z
      DOI: 10.1177/09544070221148233
       
  • Analysis of ride comfort and road friendliness of heavy vehicle inertial
           suspension based on the ground-hook control strategy

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      Authors: Dedi Yang, Xiaofeng Yang, Yujie Shen, Yanling Liu, Shuilan Bi, Xiaofu Liu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In order to comprehensively improve the ride comfort performance and the road friendliness performance of the heavy vehicles, an inertial suspension using ground-hook (GH) control is proposed in this paper, and the suspension performances are compared at different loading rates and driving speeds. Firstly, a half vehicle model of the inertial suspension of the heavy vehicle based on the GH control is established. Then, the key parameters of the GH inertial suspension are optimized by the genetic algorithm and the system simulations are carried out. By comparing to the conventional passive suspension, the root-mean-square (RMS) of the vertical acceleration of the body centroid is reduced by 4.87%, and the RMS of the dynamic tire loads of the front and the rear wheels are reduced by 16.19% and 10.02%, respectively. Results show that the GH inertial suspension can effectively coordinate and improve the ride comfort and road friendliness of heavy vehicles simultaneously.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-23T10:37:51Z
      DOI: 10.1177/09544070231151812
       
  • The testing of pneumatic tyres for the interpretation of tyre behaviour
           for road/rail vehicles when operating on rails

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      Authors: Stefan Müller, Michael Blundell
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      This paper describes a programme of tyre tests using a purpose built tyre test rig designed specifically to investigate the behaviour of tyres that are used with Road-Rail Vehicles (RRVs). These vehicles are used extensively by the rail industry to support the maintenance of existing rail lines and new construction works. In many cases, using a vehicle that can only operate on the road, or a rail engine that can only operate on tracks will not provide a suitable or effective solution for the task in hand. RRVs are able to operate on both roads and rail, and as such provide a very flexible solution to the rail industry. When operating on the road, RRVs use pneumatic tyres to control their motion and act to all intent and purpose as a normal road vehicle. When operating on rail lines RRVs use a combination of the pneumatic tyres and standard steel rail wheels to control their motion. The rail wheels maintain the directional stability on the track and the pneumatic tyres provide the tractive force to drive and brake the vehicle. Unlike standard road or rail vehicles, there is to date no predictive engineering practice that allows the use of computer simulation to design and optimise the performance of RRVs when they are operating on rails. Computer tools, such as multi-body systems (MBS) analysis are used extensively to design both road and rail vehicles. For road vehicles a tyre model is needed to represent the behaviour in the contact patch between the tyre and the road. For rail vehicles a model is needed to represent the contact force between the train wheel and the track. In both these applications the behaviour is well understood and over the last half century mathematical models have been developed that allow accurate and useful simulation to support the design of new vehicles and trains. In contrast, RRVs have evolved essentially as modifications to standard road vehicles. While the base vehicle may be very well designed to perform on the road, the performance on rail is based on experience and some testing. There is no up-front science involved in designing a RRV to perform effectively during this very important phase of its operation. In order to develop an accurate model to predict RRV performance on rails it is clear that a model of the behaviour of the tyre when in contact with the rail is needed. To date, no such model exists and additionally the testing needed to generate data that could be used to develop a model has never been carried out. The work described here addresses this with the design and build of a unique test rig that can be used to test tyres on rails for a range of operating conditions, and produce a set of initial results that provide a framework for a future tyre/rail model. The paper concludes with a review of the behaviour measured and provides new insights into how well tyres perform on rails and also where the behaviour differs from the well understood behaviour of tyres operating on roads. The important behaviours that would provide the main parameters for a new empirical tyre model are also identified and discussed.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-21T11:35:42Z
      DOI: 10.1177/09544070221148289
       
  • Research and application of load spectrum technology of reliability
           running test method for vehicle

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      Authors: Hongjie Jin, Liguo Zang, Yvlin Mao, Cheng Xue, Jing Jiao
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In order to maximize the use of load spectrum data in vehicle reliability driving test, as much as possible to solve practical problems, this paper preprocesses, edits, and compiles the original data obtained based on the multi-channel data acquisition system firstly. Then the effective and simplified application data of load spectrum of vehicle reliability driving test are obtained. Secondly, based on the measured load spectrum, the test and use equivalent relationship and acceleration coefficient of different components are calculated. The road simulation bench research is carried out to verify the reliability of the bench test and provide the basis for the indoor simulation reliability test. The reliability driving specification is studied, and the test speed of each road is determined. Meanwhile, the stress amplitude analysis method is used to analyze the fault, study the fault mechanism and improve it through optimization design. Finally, the influence mechanism of road surface on vehicle is studied by spectrum and amplitude analysis. This study which is based on solving practical problems expands the application field and direction of the measured test load spectrum from the test practice, and provides ideas and feasible methods for the application of reliable driving load spectrum.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-20T10:29:04Z
      DOI: 10.1177/09544070221150045
       
  • Design of autonomous vehicle trajectory tracking controller based on
           Neural Network Predictive Control

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      Authors: Guoqing Geng, Sinan Lu, Chen Duan, Haobin Jiang, Huarong Xiang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      When the linear Model Predictive Control (MPC) algorithm is used for trajectory tracking control of autonomous vehicles in high-speed turning conditions, the tracking accuracy is usually decreased due to the low fidelity of the predictive model. To deal with this problem, a trajectory tracking controller based on Neural Network Predictive Control (NNPC) is designed in this paper. The data collected from driving simulation experiments is used for the Back Propagation Neural Network (BPNN) training process to obtain the vehicle state predictive models. To reduce the iteration times of the rolling optimization module of NNPC, Particle Swarm Optimization (PSO) with Fitness Allocating Inertia Weights (PSO-FAIW) algorithm is proposed, which can allocate inertia weights in light of the distance between each particle’s fitness and the best fitness of the swarm. Finally, the performance of the controller designed in this paper is verified based on MATLAB /Simulink. The simulation results demonstrate that the controller proposed in this paper can give consideration to tracking accuracy and real-time performance.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-20T10:24:45Z
      DOI: 10.1177/09544070221150023
       
  • Robust AISMC-neural network observer-based control of high-speed
           autonomous vehicles with unknown dynamics

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      Authors: Hamid Taghavifar
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Substantial challenges still exist in designing path-tracking control systems for autonomous vehicles, particularly at speed limits or under varying operating conditions. Such problems arise for various reasons, such as the nonlinear characteristics of vehicular components, system-component interactions, constraints on the states and control inputs, and more. This paper focuses on designing a robust adaptive control system for high-speed autonomous vehicles in case the system dynamics are unknown or unavailable. For this purpose, an intelligent NN-based estimation system’s universal approximation potential will be leveraged, coupled to an adaptive integral sliding mode controller (AISMC). Unlike previously reported studies, the present paper considers the entire dynamics of the autonomous vehicle unknown rather than solely a part of the system or external disturbances merely. The Lyapunov stability theorem is employed to guarantee the asymptotic stability of the developed framework and to obtain the adaptation laws. A critical maneuver explores the effectiveness and robustness of the suggested framework under severe disturbances, parametric uncertainties, and high speeds. The obtained results indicate that the developed framework holds the capacity to navigate the vehicle alongside the desired trajectory and outperforms other reported studies in the literature subject to various external disturbances.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-20T01:57:42Z
      DOI: 10.1177/09544070221145742
       
  • Global-guidance chaotic multi-objective particle swarm optimization method
           for pneumatic suspension handling and ride quality enhancement on the
           basis of a thermodynamic model of a full vehicle

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      Authors: Mohammad Ghorbany, Salman Ebrahimi-Nejad, Morteza Mollajafari
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In this paper, the parameters of the validated suspension system model of a full-vehicle are tuned through design sensitivity analyses, and then Multi-Objective Particle Swarm Optimization (MOPSO) is used to enhance vehicle ride comfort, which is the vertical whole-body vibrations, and handling features, that is, roll motion and road holding, simultaneously. The parameters of this thermodynamic-based pneumatic suspension system model are comprised of the air spring reservoir volume, orifice resistance, initial volume, and pressure of the pneumatic springs. To enhance the convergence rate, computational times, and diversity of the swarm particles, we have incorporated chaotic dynamics into the MOPSO using the Logistic Map chaotic method to initialize the population and also employed the leader-based global guidance techniques to conduct the potential solutions in each iteration. The analysis of the proposed modeling and optimization results show that the suspension system has been reasonably boosted in terms of vehicle handling and ride comfort. Quantitatively, the RMS acceleration and pitch angle has been reduced by about 71% and 57%, respectively, showing a substantial improvement in passenger comfort. Furthermore, the proposed approach caused an increase in tire road-holding force by about 148% and a reduction of roll angle by 33% which results in an enhancement in vehicle handling, boosting vehicle driving safety.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-17T12:06:49Z
      DOI: 10.1177/09544070221148287
       
  • An integrated three-dimensional powertrain-vehicle dynamics model for
           tracked vehicle analysis

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      Authors: Ilango Mahalingam, Chandramouli Padmanabhan
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      A tracked vehicle employs a special transmission to generate a speed difference between the inner and outer tracks for steering. In this paper, the dynamic model of one of the most widely used steering transmissions called double differential steering has been derived and integrated with a multi-body tracked vehicle model. A simplified multi-body model for tracks has been proposed to reduce the computational and numerical difficulties arising from a detailed three-dimensional multi-body model. The accuracy of the proposed model is demonstrated by extensive comparison with a detailed multi-body model developed using the Tracked Vehicle module of the commercial software ADAMS. Simulations are carried out using the integrated tracked vehicle model to demonstrate the effects of changes in three-dimensional vehicle dynamic performance with design changes in powertrain systems.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-17T12:01:49Z
      DOI: 10.1177/09544070221147384
       
  • Investigate the effect of a novel inlet header on the thermal and
           hydraulic performance of a liquid cold plate used for cooling the Li-ion
           battery cell of electric vehicles

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      Authors: Mohammad Yacoub Al Shdaifat, Rozli Zulkifli, Kamaruzzaman Sopian, Abeer Adel Salih
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      EV batteries tend to generate a significant amount of heat due to internal resistance during operation. The LCP using the regular inlet struggles to have good fluid distribution without depending on the flow rate. The aim of the present experimental study is to introduce a new design of inlet header called shower head to be used in the liquid cold plate for cooling the battery cells. The study investigates the thermal performance improvements by using the shower head and its impact on the hydraulic performance of the liquid cold plate. The shower head is studied at Reynolds number range 382–1530 and water is the working fluid. The results indicate that the shower head achieved significant reduction in the surface temperature of the battery cell and good temperature uniformity compared to the regular inlet at all Reynolds numbers due to the ability of the shower head to achieve good fluid distribution and mixing inside the LCP. The pumping power consumption difference between the regular inlet and the shower head is not significant.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-14T07:58:46Z
      DOI: 10.1177/09544070221150763
       
  • Sparse least squares support vector machine based methods for vehicle
           driving behavior recognition

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      Authors: Dongyu Zhao, Shuen Zhao
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Intelligent vehicles are expected to accurately recognize the driving intentions of surrounding vehicles so as to precisely identify the hazards to automatic driving and accomplish reasonable motion planning. This paper introduces a model for vehicles driving behavior recognition (VDBR) based on Sparse Least Squares Support Vector Machine (S-LSSVM) by means of machine learning methods, with the subject vehicle and its surrounding vehicles as the research subject. First, the relative lateral displacement and relative lateral speed between vehicles are captured as the eigenvectors after calculation of trajectory curvature and change time window. Then, the pruning algorithm is used to make Least Squares Support Vector Machine (LSSVM) training samples sparse and the Particle Swarm Optimization algorithm (PSO) is employed to accomplish parameter tuning of S-LSSVM. Thus, a modified S-LSSVM model is constructed to grasp the interaction behavior between vehicles. The experiment results demonstrate that the S-LSSVM based model obtain better accuracy and timeliness compared with SVM and LSSVM on the Next Generation Simulation (NGSIM) dataset and the data from autonomous driving experimental platform.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-14T07:56:46Z
      DOI: 10.1177/09544070221150466
       
  • Optimal reinforcement learning and probabilistic-risk-based path planning
           and following of autonomous vehicles with obstacle avoidance

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      Authors: Hamid Taghavifar, Leyla Taghavifar, Chuan Hu, Chongfeng Wei, Yechen Qin
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In this paper, a novel algorithm is proposed for the motion planning and path following automated cars with the incorporation of a collision avoidance strategy. This approach is aligned with an optimal reinforcement learning (RL) coupled with a new risk assessment approach. For this purpose, a probabilistic function-based collision avoidance strategy is developed, and the proposed RL approach learns the probability distributions of the adjacent and leading vehicles. Subsequently, the nonlinear model predictive control (NMPC) algorithm approximates the optimal steering input and the required yaw moment to follow the safest and shortest path through the optimal RL-based probabilistic risk function framework. Additionally, it is attempted to maintain the travel speed for the ego vehicle stable such that the ride comfort is also offered for the vehicle occupants. For this purpose, the steering system dynamics are also incorporated to provide a thorough understanding of the vehicle dynamics characteristic. Different driving scenarios are employed in the present paper to evaluate the proposed algorithm’s effectiveness.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-14T07:54:08Z
      DOI: 10.1177/09544070221149278
       
  • Estimation of the state and parameter of full electric driven ground
           unmanned platform with variable configuration

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      Authors: Liya Wang, Xiaojun Xu, Tengan Zou
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      A ground unmanned platform with variable configuration can better adapt to the field combat environment, which can adjust the wheelbase and wheel track to adapt to the ground. The power system of the platform is distributed drive form, with better controllability, higher drive efficiency, and faster system response. Changes of wheelbase and wheel track can influence the position of the platform’s centroid, which is critical for dynamic control and platform state acquisition. Based on the 9DOF nonlinear vehicle model, this paper introduces the relative position parameters of the vehicle centroid and the inertial measurement unit. And this paper performs coordinate transformation to accurately estimate the state parameters such as the position of the center of mass, the speed of the vehicle, and the centroid side-slip angle according to the measurement data, avoiding estimation error due to the change of centroid position. On the basis of fusing on-board multi-sensor information such as wheel hub torque, a square-root Unscented Kalman Filtering algorithm (SR-UKF) with high stability performance that can adapt to strong nonlinear system is proposed. In the Simulink/Trucksim joint platform, the double lane change experiments with different intermediate axis positions show that the estimation method can observe the driving status and parameters of the vehicle in real time, and the tracking effect is better.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-14T07:50:29Z
      DOI: 10.1177/09544070221149275
       
  • Numerical investigation of crash behavior of vehicle side door beams under
           high-speed pole side impacts

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      Authors: Mustafa Atakan Akar, Umut Kumlu, Şafak Yıldızhan
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In side vehicle accidents, there is a very short distance between the impactor and the passenger. In such accidents, car manufacturers place impact energy absorber beams inside the door so that the passengers do not suffer from loss of life or major damage. In this study, the crashworthiness performances of impact energy absorber beams were investigated. Comparisons were made by changing the beams’ angles, materials, thickness, and cross-sections. Among the materials used (Aluminum 6061-T6 and A36 steel), Aluminum 6061T6 material stood out with its high Specific Energy Absorption (SEA) value, low reaction force, and low permanent deformation performance. The best Velocity Absorption Time (VAT) value was obtained in the combination where the angle between the two beams defined by A36 steel was 25°. It has been stated that the hexagonal cross-section door beam used is superior to the circular beam and is open to improvement.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-13T12:02:25Z
      DOI: 10.1177/09544070221145523
       
  • Coaxial laser cladding of cobalt-base alloy StelliteTM 6 on gray cast
           iron/investigations on friction, wear versus commercial brake pad, and
           corrosion characteristics

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      Authors: Maximilian Kiehl, Adriano Scheid, Karin Graf, Benedikt Ernst, Ulrich Tetzlaff
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Environmental legislation and the electrification of vehicles place increased requirements on brake disks in terms of wear and corrosion resistance. Departing from a preliminary study, the present investigation examined the friction and wear behavior as well as the corrosion properties of Stellite™ 6 coatings on gray cast iron, which were deposited by laser cladding. The friction and wear experiments were conducted on a pin-on-disk tribometer at contact pressures of 1.0 and 2.0 MPa as well as rotation speeds of 0.2, 0.4, 0.6, 0.8, and 2.0 m/s. The pins are manufactured from an automotive semi-metallic brake pad. The friction behavior of gray cast iron and Stellite™ 6 coatings is similar under changing test conditions. The tribological behavior is strongly influenced by the microstructural and mechanical properties of the coatings and the brake pad material. A third body layer of contact patches is formed on Stellite™ 6, which mainly consists of brake pad components. The transformation of the Co-matrix (fcc → hcp), subsurface fatigue, and tribo-oxidation are the main wear mechanism for Stellite™ 6. The electrochemical characteristics were analyzed by potentiodynamic polarization, and the corrosion rate was determined with Tafel plots in 3.5% NaCl solution, respectively. Compared to gray cast iron, Stellite™ 6 coatings have a pronounced corrosion resistance due to the formation of a protective passive layer of Co and Cr oxides. This corrosion resistance is mainly influenced by the microstructure. The corrosion rate of the coatings increases in parallel with the Fe dilution.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-13T12:01:25Z
      DOI: 10.1177/09544070221145512
       
  • Coordinated control of stability and economy of distributed drive electric
           vehicle based on Lyapunov adaptive theory

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      Authors: Yawei Shen, Youqun Zhao, Huifan Deng, Fen Lin, Huan Shen
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In order to solve the problem of poor coordinated control between handling stability and economy of distributed drive electric vehicles, a model reference adaptive yaw moment controller based on Lyapunov stability theory and a quadratic programing wheel torque distribution controller considering energy loss of motors are proposed. A hierarchical control strategy is adopted. The upper controller is a model reference adaptive yaw moment controller based on Lyapunov stability theory. The adaptive control law is obtained by solving the Lyapunov function, and the stability of the model reference adaptive control system is proved. The upper controller provides additional yaw moment in real time according to the vehicle state, which can ensure the handling stability of the vehicle. The lower controller adopts the quadratic programing wheel torque distribution controller considering the energy loss of the motor to realize the real-time torque distribution to the wheel. Moreover, the weight distribution of stability and economy is dynamically coordinated based on the phase portrait. The double lane changing condition and fishhook steering condition are selected, and the simulation test of the proposed control method is carried out on the CarSim/Simulink joint simulation platform. The simulation results under the above two road conditions show that the vehicle has good handling stability when using Lyapunov adaptive control method. In addition, the coordinated decision control strategy can effectively reduce the load and energy loss of hub motor.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-13T10:35:16Z
      DOI: 10.1177/09544070221147081
       
  • Maintenance cost prediction for the vehicle based on maintenance data

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      Authors: Sun Zhonghui, Guo Yanying, Sun Zhonghong, Yang Shouchen, Hao Baoyu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      With the fierce competition in the automobile market, the focus of competition in the automobile industry had gradually turned to the automobile extended warranty service. The prediction of maintenance cost was a very important premise for the formulation of automobile extended warranty service. Combining the failure frequency data of vehicles in multiple sales batches, the mixed Weibull model was used to fit the failure process, and the single vehicle failure rate prediction model was obtained; At the same time, combined with the maintenance cost data of the same batch of vehicles, the prediction model of single vehicle maintenance cost was obtained by iterative solution. Using the existing maintenance data, the maintenance cost prediction model based on user group had been verified. The results showed that the model was real, effective and had strong engineering application value.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-13T10:33:08Z
      DOI: 10.1177/09544070221147080
       
  • Coordinated control strategy for mode switching of power-split hybrid
           electric bus

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      Authors: Yang Rong, Guan Weilai, Wang Kunyu, Huang Wei, Huang Junming, Zhang Song
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In the dynamic process of mode switching of the power-split hybrid electric bus, the vehicle will have longitudinal shock due to the drastic change of the two motors’ torque and the engine’s slow response. To solved this problem, this paper will focus on the process of switching from pure electric mode to hybrid drive mode, considered the operational state changes before and after engine ignition, limited the torque fluctuation transmitted from the front planetary set to the output shaft based on the idea of motor compensation, and calculated the motor compensation torque of the rear planetary set to compensate the torque fluctuation of the output shaft, to reduce the jerk. Firstly, the dynamic models of the transmission system before and after the engine ignition are established, respectively, and then the dynamic torque of the engine is estimated by XGBoost. The estimated value is input into the model predictive controller (MPC) to track the engine speed and calculate the torque fluctuation generated by the front planetary set on the output shaft. Then, according to the estimated value of the engine torque and the predicted value of the engine’s speed, the compensation torque is calculated by the sliding mode controller (SMC). Finally, the vehicle model is built with AVL CRUISE and MATLAB/Simulink software to verify the mode switching control effect of hybrid electric bus under typical urban conditions in China. The results showed that this control strategy significantly reduces the jerk of the mode switching process.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-13T10:31:44Z
      DOI: 10.1177/09544070221145986
       
  • Vision-based driver ear recognition and spatial reconstruction

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      Authors: Cheng Peng, Jiang Liu, Tao Jiang, Xilong Zhang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      How to identify the ear hole more accurately and more quickly are critical for the active noise reduction in the road vehicle. Obscurations, causing by the long hair, the earphone, and some kind of caps, make the spatial location and orientation of the driver’s ears almost impossible. To solve these two problems, a new method was proposed to replace the original image scaling detection by combining the Haar-like algorithm with the scale size of the variable detection window in the recognition process. A depth positioning camera is added to the ear recognition, which may offer more accurate point vectors for the driver’s two ear holes. A simplified spatial reconstruction model was developed to assist the search when the piercing was occluded. After calculating the image-camera-cab projection mapping relationship, only four feature points are enough for the model’s data requirement. The test results show that the detection Frame Per Second (FPS) was improved to 8.8, and the ear hole’s positioning error is less than 0.1 cm. The proposed system can locate ear holes even with 100% obscurations. The research may have potential application as a front-end subsystem for the active noise reduction and voice interaction systems, improving the quality of acoustic control in cars.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-13T05:58:15Z
      DOI: 10.1177/09544070221145993
       
  • Accelerated durability evaluation of automotive components under
           multi-channel random loading

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      Authors: Yifu Zhou, He Li
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Accelerated durability evaluation aims to quantify the fatigue damage of automotive components in a shorter time. The quality of accelerated editing directly affects the evaluation’s efficiency and accuracy. In this paper, an index-controlled accelerated spectrum editing method is proposed, and the equivalent fatigue damage model of the component is derived. Taking an automotive steering knuckle as the verification object, the proposed accelerated editing method is evaluated from multiple perspectives. The evaluation results show that the proposed method has apparent advantages in compression efficiency, damage consistency, and retaining the frequency domain impact on the component.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-13T05:50:56Z
      DOI: 10.1177/09544070221145519
       
  • Impact of driving and driver’s operating characteristics on high fuel
           consumption set based on real-road driving data

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      Authors: Hanzhengnan Yu, Yu Liu, Hao Zhang, Jingyuan Li, Hai Liu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      As the existence of the gap between real-road vehicle fuel consumption rate and type-approval, the researches focused on real-road fuel consumption characteristics are increasing in recent years. However, the quantitative analysis about the reasons caused the real-road high fuel consumption scenarios are rarely reported. In this paper, based on the real-road driving data, the high fuel consumption scenarios in urban, suburb, and high-way conditions have been extracted, which was defined as HFC (high fuel consumption) set, and the reasons caused the HFC set were discussed from the aspect of driving characteristics and driver’s operating characteristics. Results showed that for vehicle speed and gear state factors, it showed a negative correlation with HFC set’s fuel consumption, and the effects became weaker varying to high-way condition, which were just the opposite of vehicle positive acceleration, acceleration pedal opening, and speed per positive acceleration. While the variation rate of acceleration pedal opening showed a weak or no correlation with HFC’s fuel consumption. To sum up, the ranking of each factor’s effect on real-road vehicle fuel consumption of HFC set under all the conditions, from strong to weak, should be vehicle speed per positive acceleration > acceleration pedal opening ≈ vehicle positive acceleration > gear state > vehicle speed, and the effects of acceleration pedal opening and vehicle positive acceleration were almost the same.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-12T12:52:23Z
      DOI: 10.1177/09544070221149113
       
  • Lateral semi-trailer truck control using a parameter self-learning MPC
           method in urban environment

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      Authors: Jiajia Chen, Shaodong Jiang, Zheng Zhou, Mengyu Zhang, Xiaoke Ming, Ning Guo
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      This paper analyzes the lateral control technology of autonomous semi-trailer trucks. Existing researches on the lateral control algorithm of semi-trailer trucks focus on making the head-truck or trailer follow a track well while ignoring the motion characteristics during the turning process, leading to specific security issues. Meanwhile, it is difficult to cope with the complex and uncertain factors influencing lateral control effect, such as the curvature of the desired trajectory, the load, and the velocity of the semi-trailer truck. This paper proposes a parametric self-learning model predictive control (MPC) based on the Proximal Policy Optimization of One Step (OSPPO) method to solve these problems. After modeling the kinematics of the semi-trailer truck, a lateral motion controller for the relationship between the head-truck and trailer based on the MPC method is established. The traditional MPC method has difficulty in adapting to the changeable influencing factors. Thus, a deep reinforcement learning algorithm named OSPPO is introduced to improve the flexibility of the MPC method. OSPPO establishes the nonlinear mapping relationship between the critical parameter of the MPC method and the factors influencing control effect by self-learning, avoiding a large amount of labeled data for training. In simulations, Trucksim and Matlab were used to conduct co-simulation to verify the usefulness of the control method. The method was implemented on an autonomous semi-trailer truck for many outdoor scenes. The actual experimental results showed the validity and advantages of the proposed method.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-12T12:51:53Z
      DOI: 10.1177/09544070221149068
       
  • Relevance analysis of the bushing stiffness of rear multi-link suspension
           to handling stability and ride comfort of vehicle and optimization
           research to improve both performances

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      Authors: Jin Gao, Xiaoping Qi
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      This study focuses on the relevance of bushing stiffness for E-type multi-link suspension to handling stability and ride comfort of vehicle. The influence of bushing stiffness on suspension performance is illustrated theoretically from the force point of view. The principle of the influence of bushing stiffness on vehicle handling stability and ride comfort is described. In simulation study, the influences of specific bushing stiffness on vehicle handling stability and ride comfort are analyzed. The simulation results show that the bushings stiffness of the upper and lower control arm of the suspension significantly influences vehicle handling stability and the influences are more significant in the low frequency range. The vehicle ride comfort on the random road is mainly influenced by the bushing stiffness of the top mount of shock absorber, and on bump road by the bushing stiffness of the trailing arm mostly. Finally, the NSGA-II and MOPSO algorithms are used to optimize handling stability and ride comfort. The optimization results show that the handling stability and ride comfort of the vehicle could be improved with reasonable adjustment of the bushing stiffness. The results obtained in using the NSGA-II algorithm are more suited to the optimization requirements of this study.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-12T12:51:13Z
      DOI: 10.1177/09544070221147579
       
  • Variable-stiffness optimization of CFRP body panels for body-in-white

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      Authors: Tiantong Lv, Dengfeng Wang, Xuejing Du, Junyao Yang, Zipeng Chen
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Body panels have a direct influence on the static and dynamic stiffness of the body-in-white. With the introduction of CFRP in automotive body, these panels have ushered in the potential of being designed with variable-stiffness. However, due to the inherent complexity of variable-stiffness design and the need to integrate all panels to account for their interaction on BIW, the related design issue has not been solved. This paper reports a design method to achieve the successive optimization of the thickness distribution and stacking sequence for body panels, as well as ensure basic manufacturing and blending requirements of design results. This method was applied to the virtual design of the roof, floor, outer and inner side panels of a body-in-white. Compared with original constant-stiffness CFRP components, a 16.4% weight reduction was attained, the torsional and bending stiffness, first-order torsional and bending frequencies were enhanced by 5.0%, 10.9%, 4.7%, and 7%, respectively.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-12T12:50:13Z
      DOI: 10.1177/09544070221147373
       
  • Design and implementation of passivity-based controller for active
           suspension system using port-Hamiltonian observer

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      Authors: Pramod Sistla, Krishnan Chemmangat, Sheron Figarado
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The objective of this study is to design and implement an observer for quarter-car active suspension system in Port-Hamiltonian form. A novel state observer is designed for active suspension system modelled in port-Hamiltonian form to estimate the states in presence of road disturbances. The observer is designed considering suspension deflection alone as the output, which is an easily measurable output. Performance of the proposed observer is evaluated experimentally with road disturbance input mimicking a sudden bump and a continuously varying road input, and proven to be effective in minimising the error dynamics in presence of bounded unmodelled disturbances. To prove the effectiveness of the state-estimator, an Interconnection and Damping Assignment Passivity Based Control (IDA-PBC) designed using the desired physical properties of the closed-loop system is implemented using the observer states. Experimental results of the controller implemented using the designed state observer show good improvement in the ride comfort, ride stability and suspension stroke of the active suspension system, which proves the effectiveness of the proposed port-Hamiltonian observer in terms of minimising the error dynamics.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-12T12:49:13Z
      DOI: 10.1177/09544070221147364
       
  • Model predictive control allocation based on adaptive sliding mode control
           strategy for enhancing the lateral stability of four-wheel-drive electric
           vehicles

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      Authors: Di Ao, Pak Kin Wong, Wei Huang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      A novel hierarchical direct yaw moment controller is designed to enhance the lateral stability of the four-wheel-drive electric vehicle. The adaptive sliding mode control (ASMC) technique in the upper-layer controller is employed to compute an additional yaw moment. The lower-layer controller distributes this yaw moment into each independent wheel by utilizing model predictive control allocation (MPCA). The proposed MPCA aims to mitigate the performance deterioration induced by in-wheel motor dynamics and optimize the power consumption stemming from the additional yaw moment. Co-simulation and hardware-in-the-loop (HIL) test is conducted to verify the performance of the proposed controller. Validation results show that the proposed hierarchical ASMC-MPCA controller outperforms the sliding mode control MPCA (SMC-MPCA) and the integrated nonlinear model predictive control (NMPC) with the lowest root-mean-square errors [math] of yaw rate, sideslip angle, lateral deviation, and lowest power consumption. Additionally, the chattering phenomenon in SMC-MPCA can be suppressed effectively by adaptively estimating the parameter uncertainties. The proposed ASMC-MPCA controller also consumes less computational resources than the NMPC and SMC-MPCA, which indicates that the ASMC-MPCA is more suitable for an automotive onboard controller. The comparison between hierarchical and integrated controller frameworks also shows that the hierarchical framework is more suitable for production vehicles under non-powerful vehicle control units.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-12T12:48:33Z
      DOI: 10.1177/09544070221147327
       
  • Energy absorption characteristic and crashworthiness optimization design
           of VRB-VCS structures under manufacturing constraints

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      Authors: Gan Luo, Libin Duan, Wei Xu, Xing Liu, Zhanpeng Du, Maotao Zhu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      After fully understanding the limitations of traditional variable rolled blank (VRB) and variable cross-sectional (VCS) double-hat shaped beam structures on the energy absorption ability and collision safety optimal design, we propose a variable rolled blank and variable cross-sectional (VRB-VCS) double-hat shaped beam structure with piecewise exponential function. Firstly, the thickness distribution function and the mathematical model of constraint conditions are derived under the constraints of manufacturing rollability. The corresponding finite element (FE) model of the VRB-VCS structure is validated by the dropping hammer impact axial crush experiments, which can predict the crushing process with high fidelity. Secondly, the parametric researches of the energy absorption characteristic of VRB-VCS structure are carried out based on the FE model. The reasonable range of each parameter is obtained by analyzing the influence of the thickness distribution and other key cross-sectional parameters on the energy absorption characteristic and deformation mode of VRB-VCS structure. Finally, the Pareto frontier solutions of the linear and piecewise exponential function VRB-VCS structures are obtained by the multi-objective optimization of the corresponding structures. In comparison to VCS, VRB and linear VRB-VCS structures, the proposed VRB-VCS structure has a higher energy absorption capacity and greater crashworthiness.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-12T12:47:13Z
      DOI: 10.1177/09544070221146954
       
  • Nonlinear model predictive control of a DISI turbocharged engine with
           virtual engine co-simulation and real-time experimental validation

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      Authors: Rohit Koli, Daniel Egan, Qilun Zhu, Robert Prucka
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      An increasing number of control actuators are being added to internal combustion engines to reduce fuel consumption and meet with emission standards. This research utilizes Nonlinear Model Predictive Control (NMPC) to manage a spark ignition engine equipped with a turbocharger, low pressure Exhaust Gas Recirculation (EGR), and Variable Valve Timing (VVT). This paper focuses on discussing the experimental setup and validation of the proposed NMPC strategy, while an overview of the control-oriented engine model and NMPC formulation is provided. The proposed NMPC-based engine control was implemented into a rapid prototype control system and successfully deployed during dynamometer tests. With a minimum amount of calibration effort, the NMPC exhibits sophisticated transient actuator control, which would otherwise require many calibration maps to achieve. A detailed discussion of these transient maneuvers is provided and reveals that these control actions indeed optimize the control objective function without violation of combustion and hardware capacity constraints.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-12T12:46:26Z
      DOI: 10.1177/09544070221146586
       
  • Slip ratio estimation of electric wheels based on tire force and road
           conditions

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      Authors: Hang Li, Zunyan Hu, Jiayi Hu, Jianqiu Li, Jingkang Li, Yuanyuan Li, Liangfei Xu, Shucheng Liu, Minggao Ouyang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The independently controlled electric wheels of distributed drive vehicles provide faster and more accurate actuators for vehicle slip ratio control. Meanwhile, the estimation of the slip ratio of electric wheels has been of vital importance for the dynamics control of distributed drive electric vehicles. However, the conventional slip ratio estimation method is hard to accurately estimate the slip ratio under steering conditions without multiple observations, increasing the cost and introducing errors. Considering that the output torque and motor rotation rate of electric wheels can be accurately collected, the novel slip ratio estimation method takes advantage of the signals of the electric wheels and requires fewer vehicle sensors. Based on the torsional vibration model of electric wheel, the slip ratio estimation method was proposed and validated by simulations and experiments. With the drum dynamometer, the slip ratio estimation method was applied to a single electric wheel for testing, proving the feasibility and accuracy of the proposed method. The slip ratio estimation was finally applied to a fuel cell heavy truck for road tests, of which the results show that the error index is reduced from 0.0152 to 0.0064 compared to the conventional slip ratio estimation method, confirming the good estimation performance achievable via the proposed method.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-12T10:11:13Z
      DOI: 10.1177/09544070221145979
       
  • Estimation of state parameters and road adhesion coefficients for
           distributed drive electric vehicles based on a strong tracking SCKF

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      Authors: Zhang Rongyun, Zhang Bin, Shi Peicheng, Zhao Linfeng, Feng Yongle, Liu Yaming
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      To address the difficulties in accurately measuring driving state parameters and the road adhesion coefficient, in this paper, the permanent magnet synchronous motor (PMSM) was selected as the automotive in-wheel motor, and the distributed drive electric vehicle (DDEV) simulation model was built based on CarSim and MATLAB/Simulink software. PMSM speed estimation by Adaptive Sliding Mode Observer (ASMO) was used as input information for subsequent studies of state parameters and road adhesion coefficient estimation. Next, this paper established a nonlinear three-degrees-of-freedom whole-vehicle dynamics reference model based on the Dugoff tire model. We derived a suboptimal fading factor using strong tracking theory (STT) and introduced it into the square root of the prediction error covariance of the square-root cubature Kalman filter (SCKF) algorithm. A strong tracking square-root cubature Kalman filter (ST-SCKF) observer was constructed. Improved algorithm estimation accuracy and the ability to cope with sudden changes in operating conditions improve the estimation accuracy of the DDEV driving state parameters and road adhesion coefficient. Finally, a joint CarSim and MATLAB/Simulink simulation and experiments on real vehicles were carried out. The results show that, compared to the traditional CKF (cubature Kalman filter, CKF) and SCKF algorithms, the ST-SCKF algorithm is able to estimate vehicle state parameters and road adhesion coefficients more accurately while maintaining good estimation accuracy for docked road conditions with sudden changes in the road adhesion coefficient.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-12T10:08:04Z
      DOI: 10.1177/09544070221145829
       
  • The tire slip angle estimation algorithm based on intelligent tire
           technology

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      Authors: Bo Li, Tianli Gu, Zhenqiang Quan, Shaoyi Bei, Dan Zhou, XinYe Zhou, Xiao Han
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Tire slip angle is a very important parameter in tire/vehicle dynamics control. This paper proposes a tire slip angle estimation method that combines intelligent tire technology and machine learning. Firstly, a finite element model of a 205/55/R16 radial tire was established by ABAQUS software, and the tire finite element model is verified by the radial stiffness experiment and dynamics experiment. Secondly, the curves of lateral acceleration and the curves of the lateral displacement obtained by five virtual tri-axial accelerometers installed on the inner line of the finite element tire under different slip angles, tire pressures, loads, and speeds were analyzed. Finally, combined with linear correlation analysis method, the promising input eigenvalues were determined, and three slip angle prediction models were trained based on the same set of train sets to predict the same set of test sets. The prediction results showed that the slip angle prediction curve of BP model has the highest degree of coincidence with the actual curve, and the mean absolute percentage error is 3.55%, indicating that the slip angle estimation algorithm proposed in this paper is feasible, which is very important for the stability control of the vehicle.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-12T08:10:46Z
      DOI: 10.1177/09544070221145743
       
  • New design for unconventional timing silent chain system of inline engine

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      Authors: Lichi An, Yabing Cheng, Jiabao Li, Haigang Zhou
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      More and more unconventional timing silent chain systems are used in the low-emission vehicles or hybrid vehicles, but engineering practices show that the classical design method cannot ensure the stability and the feasibility anymore. According to the angular velocity fluctuations of crankshaft, the maximum accumulation length is calculated to design the ideal path of the tension side chain. The tension rate is defined to determine the ideal chain path at the loose side. In order to match the ideal chain paths with the actual chain length, the pitch variation algorithm is proposed. Based on a specific inline engine, the unconventional timing silent chain system is designed by the classical design method and the new design method respectively. The design process proves that the new method is belonging to a real parametric design, and it can expediently and quickly obtain the results. With the dynamics simulation comparison, the results show that the operation performance of the unconventional timing system can be roundly and significantly improved by using the new design method. Furtherly, this new design method is not only suitable for the unconventional timing system, but also suitable for the other types of timing systems.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-11T10:39:36Z
      DOI: 10.1177/09544070221142359
       
  • Effects and mechanism of pilot diesel injection strategies on combustion
           and emissions of natural gas engine

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      Authors: Wu Binyang, Yang Puze, Luo Yinmi, Jia Zhi
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The research objectives of pilot diesel injection (PDI) ignition natural gas technology include high efficiency, clean combustion, and low pilot diesel mass. This study is based on a single-cylinder thermodynamic engine, combined with the CONVERGE simulation model and CHEMKIN chemical reaction kinetics model. The effects and mechanisms of various PDI strategies on the mixture equivalent ratio, temperature, and characteristics of combustion and emissions were investigated. The experimental results showed that the best PDI mass was 8 mg/cycle. The thermal atmosphere and activity in the cylinder were improved with an increase in PDI mass from 2 to 8 mg/cycle, which stabilized the mixture combustion. Further, the effects of different pilot injection timing (PIT) on combustion and emissions were investigated via experiments and simulation by controlling the operating conditions and maintaining a constant PDI total mass. The results show that the diesel had a single low-temperature reaction path when the PIT was close to the top dead center, whereas the PIT at the early stage of the compression stroke (CS) changed the chemical reaction path and accelerated the transformation of CH3 to CH2O, accumulating numerous active groups and accelerating the combustion rate, which is difficult to control the ignition phase. The reaction path of the double PDI strategy was similar to that of the PIT at the early CS stage, and its combustion is closed to premixed combustion; however, the accumulation of active groups was relatively small, and the combustion rate was relatively slow because the ignition phase was controlled by the second PDI, making the combustion phase easy to control. Finally, with the double PDI strategy that had the advantages of efficient combustion and avoidance of knock, the gross indicated thermal efficiency reached 49.3% that involved a −60°crank angle (CA) after top dead center (ATDC) first injection and −4°CA ATDC second injection.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-06T12:08:33Z
      DOI: 10.1177/09544070221145738
       
  • Modeling and stability analysis of car-following behavior for connected
           vehicles by considering driver characteristic

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      Authors: Wenjie Wang, Minghui Ma, Shidong Liang, Jiacheng Xiao, Naitong Yuan
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      Research of car-following behavior is very important to alleviate traffic congestion and ensure traffic safety. To describe the car-following behavior of connected vehicles and restore the real driving environment, this paper presents an improved car-following model for connected vehicles by considering driver characteristic and speed information of multiple vehicles, which reflects the interaction between adjacent connected vehicles and the influence of driver characteristic on the stability of car-following. The linear stability analysis and nonlinear stability analysis prove that the improved model is effective and can promote the stability of traffic flow more than other models. In addition, the numerical simulations show that the new model performs better in eliminating disturbances than other models. Finally, the parameters of proposed model are calibrated based on NGSIM data. The results show that the new model performs well in car-following process, keeping a safe distance from the leader vehicle without sudden acceleration and deceleration. The new model also can predict the acceleration behavior of the leader vehicle after emergency brake. In summary, the model proposed in this paper can be used as active safety technology to prevent collision accidents, or as a user-defined function or model in the traffic simulation software, or as car-following strategy in driverless algorithms.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-06T12:06:33Z
      DOI: 10.1177/09544070221145478
       
  • Research on characteristic parameter selection and attention-GRU-based
           model for braking intention identification

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      Authors: Xuebo Li, Jian Ma, Xuan Zhao, Lu Wang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      The braking intention is of great significance to the realization of driver assistant features, the improvement of braking safety, and the maximization of energy recovery efficiency for electric vehicles. With the aim of accurate identification of braking intention, an identification model based on Gated Recurrent Unit (GRU) Network with Attention mechanism is proposed in this paper. Based on numerous vehicle braking test data, braking process analysis, characteristic parameters selection, identification model training, and verification are carried out. Through the difference analysis based on the Kruskal-Wallis test and the importance evaluation based on random forest, combined with the real-time requirements of practical application, the appropriate characteristic parameters are selected as the model input. The attention mechanism is introduced into the proposed model, which can improve identification accuracy by capturing valuable feature information. The comparative verification results show that the Attention-GRU model performs better than the other three comparison models, and its identification accuracy is 96.7%, of which the accuracy of slight braking, normal braking, and emergency braking are 96.3%, 95.8%, and 100% respectively. The identified braking intention can provide an effective basis for the establishment of vehicle control strategies.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-06T12:04:32Z
      DOI: 10.1177/09544070221145474
       
  • Obstacle avoidance trajectory planning strategy considering network
           communication constraints

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      Authors: Zhongkai Luan, Shuangquan Zheng, Guan Zhou, Wanzhong Zhao, Chunyan Wang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, Ahead of Print.
      In obstacle avoidance trajectory planning, the environmental information collected by onboard and roadside sensors must be transmitted to the intelligent vehicle controller through network communication such as the CAN network and DSRC. However, the inherent network communication constraints such as delay and loss will lead to obstacle avoidance errors. To this end, a game deep Q-learning (GDQN) obstacle avoidance strategy is proposed combining deep Q-learning and the game theory reward strategy. The deep Q-learning network realises the modelling and description of the uncertainty of communication constraints. The obstacle avoidance reward strategy is presented by integrating the rules of traffic environment and vehicle dynamics. A scene preprocessing algorithm based on the artificial potential field method is proposed, which transforms the search problem of the optimal obstacle avoidance trajectory in the global scene into the search in the banded area to reduce the demand for computing power to the greatest extent. The experimental results show that compared with the existing research, the proposed method effectively solves the obstacle avoidance trajectory planning problem when the network has communication constraints and effectively balances traffic safety and vehicle stability in the process of obstacle avoidance.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
      PubDate: 2023-01-06T11:55:22Z
      DOI: 10.1177/09544070221130553
       
  • Tire deformation measurement technology based on digital image correlation
           method

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