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COMPUTER SCIENCE (1159 journals)                  1 2 3 4 5 6 | Last

Showing 1 - 200 of 872 Journals sorted alphabetically
3D Printing and Additive Manufacturing     Full-text available via subscription   (Followers: 13)
Abakós     Open Access   (Followers: 4)
ACM Computing Surveys     Hybrid Journal   (Followers: 23)
ACM Journal on Computing and Cultural Heritage     Hybrid Journal   (Followers: 9)
ACM Journal on Emerging Technologies in Computing Systems     Hybrid Journal   (Followers: 13)
ACM Transactions on Accessible Computing (TACCESS)     Hybrid Journal   (Followers: 3)
ACM Transactions on Algorithms (TALG)     Hybrid Journal   (Followers: 16)
ACM Transactions on Applied Perception (TAP)     Hybrid Journal   (Followers: 6)
ACM Transactions on Architecture and Code Optimization (TACO)     Hybrid Journal   (Followers: 9)
ACM Transactions on Autonomous and Adaptive Systems (TAAS)     Hybrid Journal   (Followers: 7)
ACM Transactions on Computation Theory (TOCT)     Hybrid Journal   (Followers: 12)
ACM Transactions on Computational Logic (TOCL)     Hybrid Journal   (Followers: 4)
ACM Transactions on Computer Systems (TOCS)     Hybrid Journal   (Followers: 18)
ACM Transactions on Computer-Human Interaction     Hybrid Journal   (Followers: 14)
ACM Transactions on Computing Education (TOCE)     Hybrid Journal   (Followers: 5)
ACM Transactions on Design Automation of Electronic Systems (TODAES)     Hybrid Journal   (Followers: 1)
ACM Transactions on Economics and Computation     Hybrid Journal  
ACM Transactions on Embedded Computing Systems (TECS)     Hybrid Journal   (Followers: 4)
ACM Transactions on Information Systems (TOIS)     Hybrid Journal   (Followers: 21)
ACM Transactions on Intelligent Systems and Technology (TIST)     Hybrid Journal   (Followers: 8)
ACM Transactions on Interactive Intelligent Systems (TiiS)     Hybrid Journal   (Followers: 3)
ACM Transactions on Multimedia Computing, Communications, and Applications (TOMCCAP)     Hybrid Journal   (Followers: 10)
ACM Transactions on Reconfigurable Technology and Systems (TRETS)     Hybrid Journal   (Followers: 7)
ACM Transactions on Sensor Networks (TOSN)     Hybrid Journal   (Followers: 9)
ACM Transactions on Speech and Language Processing (TSLP)     Hybrid Journal   (Followers: 11)
ACM Transactions on Storage     Hybrid Journal  
ACS Applied Materials & Interfaces     Full-text available via subscription   (Followers: 25)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 3)
Acta Universitatis Cibiniensis. Technical Series     Open Access  
Ad Hoc Networks     Hybrid Journal   (Followers: 11)
Adaptive Behavior     Hybrid Journal   (Followers: 11)
Advanced Engineering Materials     Hybrid Journal   (Followers: 26)
Advanced Science Letters     Full-text available via subscription   (Followers: 9)
Advances in Adaptive Data Analysis     Hybrid Journal   (Followers: 8)
Advances in Artificial Intelligence     Open Access   (Followers: 16)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5)
Advances in Computational Mathematics     Hybrid Journal   (Followers: 15)
Advances in Computer Science : an International Journal     Open Access   (Followers: 14)
Advances in Computing     Open Access   (Followers: 2)
Advances in Data Analysis and Classification     Hybrid Journal   (Followers: 51)
Advances in Engineering Software     Hybrid Journal   (Followers: 26)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 10)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 26)
Advances in Human-Computer Interaction     Open Access   (Followers: 20)
Advances in Materials Sciences     Open Access   (Followers: 16)
Advances in Operations Research     Open Access   (Followers: 11)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Remote Sensing     Open Access   (Followers: 39)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Advances in Technology Innovation     Open Access   (Followers: 2)
AEU - International Journal of Electronics and Communications     Hybrid Journal   (Followers: 8)
African Journal of Information and Communication     Open Access   (Followers: 8)
African Journal of Mathematics and Computer Science Research     Open Access   (Followers: 4)
Air, Soil & Water Research     Open Access   (Followers: 9)
AIS Transactions on Human-Computer Interaction     Open Access   (Followers: 6)
Algebras and Representation Theory     Hybrid Journal   (Followers: 1)
Algorithms     Open Access   (Followers: 11)
American Journal of Computational and Applied Mathematics     Open Access   (Followers: 4)
American Journal of Computational Mathematics     Open Access   (Followers: 4)
American Journal of Information Systems     Open Access   (Followers: 5)
American Journal of Sensor Technology     Open Access   (Followers: 4)
Anais da Academia Brasileira de Ciências     Open Access   (Followers: 2)
Analog Integrated Circuits and Signal Processing     Hybrid Journal   (Followers: 7)
Analysis in Theory and Applications     Hybrid Journal   (Followers: 1)
Animation Practice, Process & Production     Hybrid Journal   (Followers: 5)
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Data Science     Hybrid Journal   (Followers: 11)
Annals of Mathematics and Artificial Intelligence     Hybrid Journal   (Followers: 7)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of Software Engineering     Hybrid Journal   (Followers: 13)
Annual Reviews in Control     Hybrid Journal   (Followers: 6)
Anuario Americanista Europeo     Open Access  
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applied and Computational Harmonic Analysis     Full-text available via subscription   (Followers: 2)
Applied Artificial Intelligence: An International Journal     Hybrid Journal   (Followers: 14)
Applied Categorical Structures     Hybrid Journal   (Followers: 2)
Applied Clinical Informatics     Hybrid Journal   (Followers: 2)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Computer Systems     Open Access   (Followers: 1)
Applied Informatics     Open Access  
Applied Mathematics and Computation     Hybrid Journal   (Followers: 33)
Applied Medical Informatics     Open Access   (Followers: 11)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Soft Computing     Hybrid Journal   (Followers: 16)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 4)
Architectural Theory Review     Hybrid Journal   (Followers: 3)
Archive of Applied Mechanics     Hybrid Journal   (Followers: 5)
Archive of Numerical Software     Open Access  
Archives and Museum Informatics     Hybrid Journal   (Followers: 134)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 4)
Artifact     Hybrid Journal   (Followers: 2)
Artificial Life     Hybrid Journal   (Followers: 7)
Asia Pacific Journal on Computational Engineering     Open Access  
Asia-Pacific Journal of Information Technology and Multimedia     Open Access   (Followers: 1)
Asian Journal of Computer Science and Information Technology     Open Access  
Asian Journal of Control     Hybrid Journal  
Assembly Automation     Hybrid Journal   (Followers: 2)
at - Automatisierungstechnik     Hybrid Journal   (Followers: 1)
Australian Educational Computing     Open Access   (Followers: 1)
Automatic Control and Computer Sciences     Hybrid Journal   (Followers: 4)
Automatic Documentation and Mathematical Linguistics     Hybrid Journal   (Followers: 5)
Automatica     Hybrid Journal   (Followers: 11)
Automation in Construction     Hybrid Journal   (Followers: 6)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 8)
Basin Research     Hybrid Journal   (Followers: 5)
Behaviour & Information Technology     Hybrid Journal   (Followers: 52)
Biodiversity Information Science and Standards     Open Access  
Bioinformatics     Hybrid Journal   (Followers: 273)
Biomedical Engineering     Hybrid Journal   (Followers: 16)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 14)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 17)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 33)
Briefings in Bioinformatics     Hybrid Journal   (Followers: 45)
British Journal of Educational Technology     Hybrid Journal   (Followers: 127)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 10)
c't Magazin fuer Computertechnik     Full-text available via subscription   (Followers: 2)
CALCOLO     Hybrid Journal  
Calphad     Hybrid Journal  
Canadian Journal of Electrical and Computer Engineering     Full-text available via subscription   (Followers: 14)
Capturing Intelligence     Full-text available via subscription  
Catalysis in Industry     Hybrid Journal   (Followers: 1)
CEAS Space Journal     Hybrid Journal   (Followers: 1)
Cell Communication and Signaling     Open Access   (Followers: 1)
Central European Journal of Computer Science     Hybrid Journal   (Followers: 5)
CERN IdeaSquare Journal of Experimental Innovation     Open Access  
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 15)
ChemSusChem     Hybrid Journal   (Followers: 7)
China Communications     Full-text available via subscription   (Followers: 7)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
CIN Computers Informatics Nursing     Full-text available via subscription   (Followers: 12)
Circuits and Systems     Open Access   (Followers: 16)
Clean Air Journal     Full-text available via subscription   (Followers: 2)
CLEI Electronic Journal     Open Access  
Clin-Alert     Hybrid Journal   (Followers: 1)
Cluster Computing     Hybrid Journal   (Followers: 1)
Cognitive Computation     Hybrid Journal   (Followers: 4)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 13)
Communication Methods and Measures     Hybrid Journal   (Followers: 12)
Communication Theory     Hybrid Journal   (Followers: 20)
Communications Engineer     Hybrid Journal   (Followers: 1)
Communications in Algebra     Hybrid Journal   (Followers: 3)
Communications in Partial Differential Equations     Hybrid Journal   (Followers: 3)
Communications of the ACM     Full-text available via subscription   (Followers: 54)
Communications of the Association for Information Systems     Open Access   (Followers: 18)
COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering     Hybrid Journal   (Followers: 3)
Complex & Intelligent Systems     Open Access  
Complex Adaptive Systems Modeling     Open Access  
Complex Analysis and Operator Theory     Hybrid Journal   (Followers: 2)
Complexity     Hybrid Journal   (Followers: 6)
Complexus     Full-text available via subscription  
Composite Materials Series     Full-text available via subscription   (Followers: 9)
Computación y Sistemas     Open Access  
Computation     Open Access  
Computational and Applied Mathematics     Hybrid Journal   (Followers: 2)
Computational and Mathematical Methods in Medicine     Open Access   (Followers: 2)
Computational and Mathematical Organization Theory     Hybrid Journal   (Followers: 2)
Computational and Structural Biotechnology Journal     Open Access   (Followers: 2)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Astrophysics and Cosmology     Open Access   (Followers: 1)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 12)
Computational Chemistry     Open Access   (Followers: 2)
Computational Cognitive Science     Open Access   (Followers: 2)
Computational Complexity     Hybrid Journal   (Followers: 4)
Computational Condensed Matter     Open Access  
Computational Ecology and Software     Open Access   (Followers: 9)
Computational Economics     Hybrid Journal   (Followers: 9)
Computational Geosciences     Hybrid Journal   (Followers: 15)
Computational Linguistics     Open Access   (Followers: 23)
Computational Management Science     Hybrid Journal  
Computational Mathematics and Modeling     Hybrid Journal   (Followers: 8)
Computational Mechanics     Hybrid Journal   (Followers: 4)
Computational Methods and Function Theory     Hybrid Journal  
Computational Molecular Bioscience     Open Access   (Followers: 2)
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computational Particle Mechanics     Hybrid Journal   (Followers: 1)
Computational Research     Open Access   (Followers: 1)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computational Science and Techniques     Open Access  
Computational Statistics     Hybrid Journal   (Followers: 13)
Computational Statistics & Data Analysis     Hybrid Journal   (Followers: 31)
Computer     Full-text available via subscription   (Followers: 87)
Computer Aided Surgery     Hybrid Journal   (Followers: 3)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 7)
Computer Communications     Hybrid Journal   (Followers: 10)
Computer Engineering and Applications Journal     Open Access   (Followers: 5)
Computer Journal     Hybrid Journal   (Followers: 8)
Computer Methods in Applied Mechanics and Engineering     Hybrid Journal   (Followers: 21)
Computer Methods in Biomechanics and Biomedical Engineering     Hybrid Journal   (Followers: 10)
Computer Methods in the Geosciences     Full-text available via subscription   (Followers: 1)
Computer Music Journal     Hybrid Journal   (Followers: 16)
Computer Physics Communications     Hybrid Journal   (Followers: 6)
Computer Science - Research and Development     Hybrid Journal   (Followers: 7)
Computer Science and Engineering     Open Access   (Followers: 17)
Computer Science and Information Technology     Open Access   (Followers: 12)
Computer Science Education     Hybrid Journal   (Followers: 13)
Computer Science Journal     Open Access   (Followers: 20)

        1 2 3 4 5 6 | Last

Journal Cover Asian Journal of Control
  [SJR: 0.862]   [H-I: 34]   [0 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1561-8625 - ISSN (Online) 1934-6093
   Published by John Wiley and Sons Homepage  [1589 journals]
  • Viability Criteria for a Switched System on Bounded Polyhedron
    • Authors: JianFeng Lv; Yan Gao, Na Zhao
      Abstract: The viability of a switched system on a bounded polyhedron set, which is expressed by some linear inequalities, is investigated. Based on nonsmooth analysis and the properties of the tangent cone, a necessary and sufficient condition for viability is proposed. It is shown that the viability of a system is equivalent to the consistency of some systems of linear inequalities. Specifically, a viability condition for a switched system on a bounded polyhedron is presented. According to this condition, determining the viability of a bounded polyhedron can be transformed into verifying certain conditions at vertices of each facet. The method of determining viability, which transforms verifying the condition from infinite points to finite ones, can be implemented easily in practice. An algorithm to determine the viability for the switched system is constructed by using convex analysis. In addition, the approach can be extended to the switched system in which a control input is present. Finally, an example is listed to illustrate the effectiveness of the results.
      PubDate: 2017-12-05T10:31:16.541028-05:
      DOI: 10.1002/asjc.1719
  • Fractional Order Synchronous Reluctance Motor: Analysis, Chaos Control and
           FPGA Implementation
    • Authors: Karthikeyan Rajagopal; Fahime Nazarimehr, Anitha Karthikeyan, Ashokkumar Srinivasan, Sajad Jafari
      Abstract: This paper deals with the dynamical analysis and chaos control in a fractional order synchronous reluctance motor (FOSyncRM). Equilibrium points, characteristic equations and Eigen values of both commensurate and incommensurate FOSyncRM are presented. finite-time Lyapunov exponents of the FOSyncRM system for fixed and varied parameters are investigated along with the bifurcation plots. Fractional order bifurcation plots are derived to show that the system shows more complex chaotic oscillations in fractional order. Chaos control in the FOSyncRM system is achieved using adaptive sliding mode controllers and the entire control algorithm is implemented in FPGA.
      PubDate: 2017-12-05T10:31:12.684793-05:
      DOI: 10.1002/asjc.1690
  • The Qualitative Properties of Symmetric Open-Loop Nash Equilibria in the
           State-Control Dynamic System in Differential Games
    • Authors: Shao-Chieh Hsueh; Chen Ling
      Abstract: The local stability, steady state comparative statics, and local comparative dynamics of symmetric open-loop Nash equilibria in the state-control dynamic system for a seemingly ubiquitous class of discounted infinite horizon differential games are investigated. It is shown that most of the useful qualitative results occur because the same small number of assumptions is being made about the mathematical structure of the integrand and/or state equations. Applications of the results to exhaustible resource extraction and capital accumulation differential games are provided.
      PubDate: 2017-12-05T10:30:32.672693-05:
      DOI: 10.1002/asjc.1700
  • Nonlinear Control Method for Nonlinear Systems with Unknown Perturbations
           by Combining Left and Right Factorization
    • Authors: Fazhan Tao; Mingcong Deng
      Abstract: In this paper, nonlinear control design scheme for a class of nonlinear systems is proposed based on operator coprime factorization theory. In detail, two stable controllers are provided to design a Bezout identity by combining left factorization (not coprime) with right factorization. Based on the proposed design method, a realization approach to left coprime factorization for the nonlinear system is obtained, which provides an effective framework for constructing left coprime factorization. Meanwhile, internal-output stability of the nonlinear system is guaranteed. After that, based on the obtained left coprime factorization, the cases of the nonlinear systems with perturbations are discussed for guaranteeing robust stability for the perturbed systems. For the perturbations, two different cases, known bounded perturbations and unknown bounded perturbations, are investigated from different viewpoints to analyze robust stability issue for the perturbed systems. Finally, a simulation example is given to confirm the effectiveness of the proposed design method.
      PubDate: 2017-12-05T10:25:48.997919-05:
      DOI: 10.1002/asjc.1701
  • Time-Varying Stabilizers for Stochastic Systems with no Unforced Dynamics
    • Authors: Patrick Florchinger
      Abstract: This paper is concerned with the stabilizability of nonlinear stochastic systems with no unforced dynamics. Sufficient conditions allowing to design explicitly time–varying feedback laws which render such systems asymptotically stable in probability are given. The techniques used in this work involve the stochastic Lyapunov analysis combined with the stochastic version of the La Salle invariance principle. The interest of our results is that the systems considered in the present paper cannot in general be stabilized via time-invariant feedback laws.
      PubDate: 2017-12-05T10:25:25.705973-05:
      DOI: 10.1002/asjc.1703
  • A Novel Application of Minimax LQG Control Technique for High-speed Spiral
    • Authors: H. Habibullah; H. R. Pota, I. R. Petersen
      Abstract: Over the last two decades, increasing the scanning speed of an atomic force microscopy (AFM) has been attempted either by applying novel controllers, using alternative scanning methods, or by modifying the hardware setup. This paper demonstrates, the first two approaches to achieve high-speed AFM image scanning. A robust minimax linear quadratic Gaussian (LQG) controller is designed and spiral scanning is considered as an alternative scanning method rather than conventional raster scanning. The minimax LQG controller is designed based on an uncertain system model which is constructed by measuring the plant variations due to variations in sample mass and also modeling error between the measured and model frequency responses. This controller is also robust against uncertainties introduced as a result of variations of sample mass, spillover dynamics of the scanner at frequencies higher than the first resonance frequency of the scanner, and variation in plant transfer functions due to temperature and humidity. The designed controller is experimentally implemented on an AFM using a dSPACE ds-1103 real-time prototyping system and open-loop and closed-loop spiral imaging performances are evaluated. The proposed controller provides sufficient damping at the resonant modes to accurately track the sinusoidal reference signal and generate vibration free images. Also, creep, hysteresis, and cross-coupling effects are significantly reduced. The experimental results show that the proposed scheme outperforms the open-loop case and some other existing approaches.
      PubDate: 2017-12-05T10:15:43.786786-05:
      DOI: 10.1002/asjc.1691
  • Motion Control of a Nonholonomic Mobile Manipulator in Task Space
    • Authors: Shengfeng Zhou; Yazhini C. Pradeep, Ming Zhu, Kendrick Amezquita-Semprun, Peter Chen
      Abstract: In this paper, the motion control of a mobile manipulator subjected to nonholonomic constraints is investigated. The control objective is to design a computed-torque controller based on the coupled dynamics of the mobile manipulator. The proposed controller achieves the capability of simultaneous tracking of a reference velocity for the mobile base and a reference trajectory for the end-effector. The aforementioned reference velocity and trajectory are defined in the task space, such task setting imitates the actual working conditions of a mobile manipulator and thus makes the control problem practical. To solve this tracking problem, a steering velocity is firstly designed based on the first-order kinematic model of the nonholonomic mobile base via dynamic feedback linearization. The main merit of the proposed steering velocity design is that it directly utilizes the reference velocity set in the task space without requiring the knowledge of a reference orientation. A torque controller is subsequently developed based on a proposed Lyapunov function which explicitly considers the coupled dynamics of the mobile manipulator to ensure the mobile base and end-effector track the reference velocity and trajectory respectively. This proposed computed-torque controller is able to realize asymptotic stability of both the base velocity tracking error and the end-effector motion tracking error. Simulations are conducted to demonstrate the effectiveness of the proposed controller.
      PubDate: 2017-12-05T10:10:52.263806-05:
      DOI: 10.1002/asjc.1694
  • Robust Tracking Control and Stabilization of Underactuated Ships
    • Authors: Jia-Wang Li
      Abstract: This paper addresses the problem of tracking control and stabilization for underactuated ships subjected to parametric modeling uncertainties. By designing a novel error state transformation scheme, some auxiliary variables are provided to be regarded as additional virtual control signals, while these variables can change their structures for different reference trajectories. Then, a robust control scheme is presented to achieve practical convergence of tracking errors and the ship's velocities to bounded neighborhoods of the origin. Simulation results are performed to illustrate the effectiveness of the proposed control scheme.
      PubDate: 2017-11-29T15:36:17.165455-05:
      DOI: 10.1002/asjc.1714
  • A new Wavelet Method for Variable-Order Fractional Optimal Control
    • Authors: Mohammad Hossein Heydari; Zakieh Avazzadeh
      Abstract: In this paper, a new computational method based on the Legendre wavelets (LWs) is proposed for solving a class of variable-order fractional optimal control problems (V-FOCPs). To do this, a new operational matrix of variable-order fractional integration (OMV-FI) in the Riemann-Liouville sense for the LWs is derived and used to obtain an approximate solution for the problem under study. Along the way the hat functions (HFs) are introduced and employed to derive a general procedure to compute this matrix. In the proposed method, the variable-order fractional dynamical system is transformed to an equivalent variable-order fractional integro-differential dynamical system, at first. Then, the highest integer order of the derivative of the state variable and the control variable are expanded by the LWs with unknown coefficients. Next, the OMV-FI in the the Riemann-Liouville sense together with some properties of the LWs are employed to achieve a nonlinear algebraic equation in place of the performance index and a nonlinear system of algebraic equations in place of the dynamical system in terms of the unknown coefficients. Finally, the method of constrained extremum is applied which consists of adjoining the constraint equations derived from the given dynamical system to the performance index by a set of undetermined Lagrange multipliers. As a result, the necessary conditions of optimality are derived as a system of algebraic equations in the unknown coefficients of the state variable, control variable and Lagrange multipliers. Furthermore, the efficiency and accuracy of the proposed method are demonstrated for some concrete examples. The obtained results show that the proposed method is very efficient and accurate.
      PubDate: 2017-11-29T15:31:23.748301-05:
      DOI: 10.1002/asjc.1687
  • Control Design for Artificial Swarm Mechanical Systems: Dynamics,
           Uncertainty, and Constraint
    • Authors: Xiaomin Zhao; Ye-Hwa Chen, Han Zhao, Fangfang Dong
      Abstract: We consider an artificial swarm system consisting of multiple agents. The agents influence each other through the attraction/repulsion, which is related to the relative positions among them. Here the collective behavior of the agents mimics some biological swarm systems. The dynamic model for each agent is built by taking the uncertainty into account. Based on the dynamic model, we propose three types adaptive robust controls, including switching type, non-switching type and fractional type, for each agent. The control design weaves together several intrinsic features of kinematics, dynamics, d'Alembert's principle, constraint, and uncertainty.
      PubDate: 2017-11-29T15:31:18.180545-05:
      DOI: 10.1002/asjc.1688
  • Stabilization of a Timoshenko Beam With Disturbance Observer-Based Time
           Varying Boundary Controls
    • Authors: Dongyi Liu; Yining Chen, Yingfeng Shang, Genqi Xu
      Abstract: This paper is concerned with the boundary feedback stabilization for a Timoshenko beam with external disturbances in the boundary inputs. Based on the idea of active disturbance rejection controls, extended state observers with the time-varying gains are designed to estimate disturbances and then a control strategy is presented by canceling the disturbances via the feedback channels. The well-posedness of the resulting closed-loop system is proved by the dual theory and admissibility theory, and the relationship between the stability and the disturbance is interpreted by Lyapunov's second method. At the end, the numerical experiment illustrate the effectiveness of the proposed control strategy.
      PubDate: 2017-11-29T15:30:33.693249-05:
      DOI: 10.1002/asjc.1678
  • The Method of Reagent Control Based on Time Series Distribution of Bubble
           Size in a Gold-Antimony Flotation Process
    • Authors: Zhongmei Li; Weihua Gui
      Abstract: Due to the distribution of bubble size changes with the reagent dosage in a flotation process, a dosage control method based on time series distribution of bubble size during the gold-antimony flotation process is proposed. Firstly, since the flotation conditions cannot be described fully by the features of a single froth image, the concept of cumulative distribution function (CDF) is presented for describing the time series distribution of consecutive multi-frame bubble sizes, and approximated by a third order B-spline function. After that, a method that combines an radial basis function (RBF) neural network with the genetic algorithm (GA-RBF) is used to obtain the optimal CDF of the bubble size, then, a projection pursuit method is employed to reduce the multi-dimensional weights. Finally, a nonlinear prediction model combining reagent dosage and the projection vector is constructed based on partial least square through spline transformation (PLSS). The error between the output and the given CDF can be optimized by a differential evolution algorithm. The industrial experiment demonstrates the effectiveness of the proposed method.
      PubDate: 2017-11-29T15:27:38.887142-05:
      DOI: 10.1002/asjc.1723
  • Robust Optimal Control of Nonlinear Systems With System Disturbance During
           Feedback Disruption
    • Authors: Sang-Young Oh; Ho-Lim Choi
      Abstract: In this paper, a robust optimal control problem of nonlinear systems with system disturbance during feedback disruption is considered. This is an extended work of previous time-delay optimal control results, by adding external disturbance in the considered system. It is shown that there exists an optimal input signal which keeps the performance error within the specified bound for the longest time. Then, it is shown that such an optimal input signal can be approximated by an implementable bang-bang input signal in terms of control performance. Two examples are given for illustration.
      PubDate: 2017-11-29T15:26:26.875562-05:
      DOI: 10.1002/asjc.1695
  • Robust Control of Permanent Magnet Synchronous Machine Based on Passivity
    • Authors: Razvan Mocanu; Alexandru Onea
      Abstract: This paper presents a robust control strategy for a Permanent Magnet Synchronous Machine (PMSM) based on passivity theory. Pre-control terms ensure robustness to variation of parameters. The nominal electrical and mechanical dynamics are treated separately and a cascade structure is obtained. A comparative analysis is done in Matlab-Simulink with a Simple Adaptive Control (SAC) strategy in terms of settling time, stationary error, time response and energy efficiency. Improvements of the proposed Passivity Based Control (PBC) strategy are shown in comparison with some other PBC controllers.
      PubDate: 2017-11-29T15:26:21.103504-05:
      DOI: 10.1002/asjc.1699
  • Trajectory Controllability of Fractional Integro-Differential Systems in
           Hilbert Spaces
    • Authors: Venkatesan Govindaraj; Raju K. George
      Abstract: In this paper, sufficient conditions for trajectory controllability of nonlinear fractional integro-differential systems involving Caputo fractional derivative of order α∈(1,2] in finite and as well as in infinite dimensional Hilbert spaces are obtained. Our tools of study include set-valued functions, theory of monotone operators and α-order cosine family of operators. The main results are well illustrated with the aid of examples.
      PubDate: 2017-11-27T04:30:32.531242-05:
      DOI: 10.1002/asjc.1685
  • On the Complexity of SOS Programming and Applications in Control Systems
    • Authors: Graziano Chesi
      Abstract: The minimization of a linear cost function subject to the condition that some matrix polynomials depending linearly on the decision variables are sums of squares of matrix polynomials (SOS) is known as SOS programming. This paper proposes an analysis of the complexity of SOS programming, in particular of the number of linear matrix inequality (LMI) scalar variables required for establishing whether a matrix polynomial is SOS. This number is analyzed for real and complex matrix polynomials, in the general case and in the case of some exact reductions achievable for some classes of matrix polynomials. An analytical formula is proposed in each case in order to provide this number as a function of the number of variables, degree and size of the matrix polynomials. Some tables reporting this number are also provided as reference for the reader. Two applications in control systems are presented in order to show the usefulness of the proposed results.
      PubDate: 2017-11-27T04:26:50.023736-05:
      DOI: 10.1002/asjc.1684
  • Exponential Stability and Delayed Impulsive Stabilization of Hybrid
           Impulsive Stochastic Functional Differential Systems
    • Authors: Dianqaing Li; Pei Cheng, Feiqi Deng
      Abstract: This paper is concerned with the stability and impulsive stabilization of hybrid impulsive stochastic functional differential systems with delayed impulses. Using the Razumikhin techniques and Lyapunov functions, some sufficient conditions for the pth moment exponential stability of the systems under consideration are established. Based on the derived stability results, impulsive controllers are designed to stabilize a given unstable linear or nonlinear hybrid stochastic delayed differential system. Different from the existing stability and impulsive stabilization results in the literature, the results obtained in this paper shown that the delayed part of impulses can make a contribution to the stability of systems. Three examples are provided to present the effectiveness and advantages of the proposed results.
      PubDate: 2017-11-27T04:26:26.440586-05:
      DOI: 10.1002/asjc.1692
  • Lyapunov Functional Approach to Stability Analysis of Riemann-Liouville
           Fractional Neural Networks with Time-Varying Delays
    • Authors: Hai Zhang; Renyu Ye, Jinde Cao, Alsaedi Ahmed, Xiaodi Li, Ying Wan
      Abstract: This paper is concerned with the globally asymptotic stability of the Riemann-Liouville fractional-order neural networks with time-varying delays. The Lyapunov functional approach to stability analysis for nonlinear fractional-order functional differential equations is discussed. By constructing an appropriate Lyapunov functional associated with the Riemann-Liouville fractional integral and derivative, the asymptotic stability criteria of fractional-order neural networks with time-varying delays and constant delays are derived. The advantage of our proposed method is that one may directly calculate the first-order derivative of the Lyapunov functional. Two numerical examples are also presented to illustrate the validity and feasibility of the theoretical results. With the increasing of the order of fractional derivatives, the state trajectories of neural networks show that the speeds of converging toward zero solution are faster and faster.
      PubDate: 2017-11-27T04:22:14.152489-05:
      DOI: 10.1002/asjc.1675
  • A Control Architecture for Time-Optimal Landing of a Quadrotor Onto a
           Moving Platform
    • Authors: Botao Hu; Lu Lu, Sandipan Mishra
      Abstract: We address the problem of autonomous landing of a quadrotor onto a heaving (moving vertically) platform in this paper. A control architecture that consists of a motion estimation module, a trajectory generation module and a tracking control module is proposed. The motion estimation module estimates the absolute motion of the platform and the quadrotor with the measurements from an on-board accelerometer and vision measurements. Based on these estimates, the trajectory generation module generates a time-optimal reference trajectory. With the reference trajectory and motion estimation, the tracking control module synthesizes a control command that enables robust tracking of the reference trajectory. Experimental results and comparison with a state-of-the-art landing controller demonstrate the effectiveness of the proposed control architecture.
      PubDate: 2017-11-27T04:21:25.47462-05:0
      DOI: 10.1002/asjc.1693
  • A Novel Robust Constraint Force Servo Control for Under-actuated
           Manipulator Systems: Fuzzy and Optimal
    • Authors: Fangfang Dong; Jiang Han, Ye-Hwa Chen, Lian Xia
      Abstract: We consider the control design for under-actuated manipulator systems. The task is to drive the system to be close to a prescribed constraint. The system contains uncertainty. It is bounded where the bounding information is prescribed by a fuzzy set (e.g., the bound is close to 1). The initial condition is also prescribed by a fuzzy set. A class of robust control is proposed, which guarantees a deterministic performance. On top of that, the choice of a control design parameter is cast into a fuzzy-theoretic setting. A performance index, consisting of accumulated fuzzy-based system performance and control cost, is proposed. The optimal control design parameters, which minimize the performance index, can be obtained by solving two algebraic quartic (fourth-order) equations. As a result, the control design problem, which addresses both fuzzy and optimal characteristics, is completely solved.
      PubDate: 2017-11-21T09:46:05.931168-05:
      DOI: 10.1002/asjc.1677
  • New Saturated Delayed Control for a Chain of Integrators with Nonlinear
    • Authors: Meng Li; Huawen Ye, Jianling Kang, Juan Zhang
      Abstract: This paper investigates the saturated delayed stabilization of a chain of integrators with higher-order nonlinear terms. With the aid of a recent state transformation, the system is transformed into a canonical form in which time delay appears in both input and states. As a result, natural cancellations can be fully used in the saturation reduction analysis, and fewer terms need to be estimated in the asymptotical stability analysis of the reduced system. In addition, a single tuneable parameter is introduced to the special state transformation, which facilitates compensating an arbitrarily large input-delay. As an example, a simplified inertia wheel pendulum system is provided with an explicit controller and numerical simulations are given to demonstrate the effectiveness of the suggested controller.
      PubDate: 2017-11-21T09:45:47.540412-05:
      DOI: 10.1002/asjc.1711
  • Robust Double-integral T-S Fuzzy Output Regulation for Nonlinear Systems
    • Authors: Kuang-Yow Lian; Chien-Hung Liu, Chian-Song Chiu
      Abstract: This paper proposes a robust double-integral T-S fuzzy output regulator design for affine nonlinear systems in the presence of parametric uncertainty and external disturbance. First, we adopt double integrators (an error integrator and an input integrator) to obtain an augmented T-S fuzzy model representation which has a common input matrix of fuzzy rules. This property yields less stability conditions. Next, by introducing a set of virtual desired variables (VDVs), a double-integral VDV-based fuzzy regulator is proposed to cope with unknown bias and to achieve asymptotical output regulation. Afterward, the controller is simplified to avoid VDV calculation and enhance robustness to uncertainty and external disturbance. In contrast to traditional regulation design, the double-integral non-VDV fuzzy regulator design reduces the number of fuzzy controller rules and stability LMIs. Moreover, the error coordinate transformation is removed and the uncertainty is allowed in this paper. Finally, a DC/DC buck converter system is taken as the example to demonstrate the expected performance.
      PubDate: 2017-11-14T00:05:43.561092-05:
      DOI: 10.1002/asjc.1652
  • Integrated Dynamics Control and Energy Efficiency Optimization for
           Overactuated Electric Vehicles
    • Authors: Boyuan Li; Haiping Du, Weihua Li, Bangji Zhang
      Abstract: A large number of studies have been conducted on the dynamics control of electric vehicles or on the optimization of their energy efficiency but few studies have looked at both of these together. In this study, an integrated dynamics control and energy efficiency optimization strategy is proposed for overactuated electric vehicles, where the control of both longitudinal and lateral dynamics is dealt with while the energy efficiency is optimized. First, considering the trade-off between control performance and energy efficiency, criteria are defined to categorize the vehicle motion status as linear pure longitudinal motion and non-linear motion or turning motion. Then different optimization targets are developed for different motion status. For the pure linear longitudinal motion and cornering motion, the energy efficiency and vehicle dynamics performance are equally important and a trade-off control performance between them needs to be achieved. For the non-linear turning motion, vehicle handling and stability performance are the primary concerns, and energy efficiency is a secondary target. Based on the defined targets, the desired longitudinal and lateral tyre forces and yaw moment are then optimally distributed to the wheel driving and steering torques. Finally numerical simulations are used to verify the effectiveness of the proposed strategies. The simulation results show that the proposed strategies can provide good dynamics control performance with less energy consumption.
      PubDate: 2017-11-08T02:26:49.108266-05:
      DOI: 10.1002/asjc.1686
  • Semi-Global Robust Output Regulation for A Class of Singular Nonlinear
           Systems with Unknown Algebraic Equations
    • Authors: Bomin Huang; Weiyao Lan
      Abstract: This paper considers semi-global robust output regulation problem for a class of singular nonlinear systems whose algebraic equations are not precisely known. Since the algebraic equations are not known, the output regulation problem of singular nonlinear systems cannot be solved by directly reducing the singular nonlinear system into a normal nonlinear system. Based on internal model principle, we convert the robust output regulation problem of singular nonlinear systems into a robust stabilization problem of an augmented singular nonlinear system. The augmented singular nonlinear system is also with unknown algebraic equations. However, without transforming the singular nonlinear system into a normal nonlinear system, it is shown that the augmented singular nonlinear system can be semi-globally stabilized by a high gain output feedback control law under some reasonable assumptions. Moreover, the semi-global stabilization control law of the augmented singular nonlinear systems also solves the semi-global robust output regulation problem of the original singular nonlinear system.
      PubDate: 2017-11-06T09:11:19.682836-05:
      DOI: 10.1002/asjc.1653
  • Estimation of Multi-Order Spectra for Nonlinear Closed-Loop Systems
    • Authors: Jialiang Zhang; Jianfu Cao
      Abstract: In this paper, a multi-order spectra estimation method is proposed for a nonlinear closed-loop system based on the Volterra series. Owing to the correlation between the noise and the input, the estimation accuracy is poor when the nonlinear spectra of the plant is obtained using the traditional estimation method. In order to overcome this problem, a two-step scheme is used to estimate the multi-order spectrum of a nonlinear system operating in closed-loop. Firstly, the generalized frequency response functions (GFRFs) from the reference signal to the input of the plant are estimated, and they are used to simulate the noise-free input spectra of the plant. Secondly, the GFRFs of the controlled plant are estimated using the noise-free input spectra and the output spectra. Because the GFRFs are multidimensional functions, the required amount of calculation for the estimation is very large. To reduce computational complexity, a simplified GFRF model is adopted to estimate the multi-order nonlinear spectrum of the plant. In this model, the GFRF is transformed to a one-dimensional function. Two simulation experiments are provided to illustrate the proposed approach.
      PubDate: 2017-11-03T03:41:19.005839-05:
      DOI: 10.1002/asjc.1679
  • Integral Sliding-Mode Observation and Control for Switched Uncertain
           Linear Time Invariant Systems: a Robustifying Strategy
    • Authors: Rosalba Galván-Guerra; Leonid Fridman, Rafael Iriarte, Juan-Eduardo Velázquez-Velázquez, Martin Steinberger
      Abstract: A robustifying methodology for switched systems with matched and unmatched uncertainties/perturbations and autonomous location transitions is presented. We avail of such methodology to design a control strategy based on integral sliding modes, thereby ensuring theoretically exact compensation of the matched uncertainties/perturbations and the minimization of the effects of the unmatched ones. An output integral sliding-mode control technique, based on a switched algebraic hierarchical observer is also proposed. This approach allows the theoretically exact compensation of the matched uncertainties/perturbations right after the first moment. The proposed approach is illustrated via numerical simulations.
      PubDate: 2017-11-03T03:41:09.370044-05:
      DOI: 10.1002/asjc.1661
  • Dynamic Output Feedback Control for Systems Subject to Actuator Saturation
           via Event-Triggered Scheme
    • Authors: Hongchao Li; Zhiqiang Zuo, Yijing Wang
      Abstract: In this paper, the event-triggered dynamic output feedback control problem for linear systems with actuator saturation is investigated. Event-triggered scheme only transmits the corresponding signal when the event-triggered condition is violated. Due to its advantage of saving communication resources, it is utilized to design the dynamic output feedback controller. A criterion is established to guarantee the stability of the closed-loop system by introducing an exponential term for the Lyapunov function, which corresponds to the exponential term in the event-triggered condition. The explicit design of the coefficient matrices of the controller is presented. Furthermore, a lower bound of the inter-event time is calculated to avoid Zeno behavior. An optimization algorithm is then formulated to maximize the estimation of the domain of attraction. Finally, a numerical example is given to illustrate the effectiveness of our methods and to show the trade-off between the size of the domain of attraction and communication resources saving.
      PubDate: 2017-11-03T03:33:13.773692-05:
      DOI: 10.1002/asjc.1662
  • Distributed Consensus of Multi-Agent Systems with Input Faults and
           Time-Varying Delays
    • Authors: M. Fattahi; A. Afshar
      Abstract: This work studies the consensus problem of multi-agent systems with input faults and time-varying delays. The assumed faults in the system are loss of effectiveness of actuator and nonlinear additive term mixed with nominal input. For system faults that are nonlinear, constraints of constant norm-bounded, sector nonlinearity, and unbounded nonlinearity with known basis functions are considered. Employing a Lyapunov–Krasovskii functional method, delay dependent consensus criteria are established to show the exponential behavior of the system. Finally, one simulation example is solved to demonstrate the advantage of the obtained results.
      PubDate: 2017-11-03T03:32:39.006043-05:
      DOI: 10.1002/asjc.1654
  • Robust Approximate Constraint-Following Control for Autonomous Vehicle
           Platoon Systems
    • Authors: Xiaomin Zhao; Y. H. Chen, Han Zhao
      Abstract: We consider an autonomous vehicle platoon system consisting of N+1 vehicles in the presence of modeling uncertainty. The uncertainty may be due to parameter variations, aerodynamics, external disturbances, etc., which is nonlinear and time-varying. Subject to the collision avoidance consideration, the original state is one-sided restricted. To resolve this restriction, we propose a state transformation to convert the bounded state into a globally unbounded state. Furthermore, motivated by the properties of artificial swarm systems, we incorporate the swarm system performance into the platoon system by treating it as a d'Alembert's constraint. By the Udwadia and Kalaba's approach, we obtain the analytic (closed-form) expression of the constraint force. Based on this, a class of robust controls for each vehicle (except the leading vehicle) is proposed to drive the platoon system to follow the ideal swarm model. Four major system performances are accomplished: (i) compact vehicle formation, (ii) collision avoidance, (iii) stable platoon system formation, (iv) global behavior.
      PubDate: 2017-10-26T18:20:44.895089-05:
      DOI: 10.1002/asjc.1676
  • L1-Gain Analysis and Control for Switched Positive Systems with Dwell Time
    • Authors: Jian Shen; Weiqun Wang
      Abstract: This paper studies the problems of L1-gain analysis and control for switched positive systems with dwell time constraint. The state-dependent switching satisfies a minimal dwell time constraint to avoid possible arbitrary fast switching. By constructing multiple linear co-positive Lyapunov functions, sufficient conditions of stability and L1-gain property are derived under the proposed switching strategy. Then, an effective state feedback controller is designed to ensure the positivity and L1-gain property of the closed-loop system. Finally, a simulation example is given to illustrate the effectiveness of the proposed method.
      PubDate: 2017-10-26T18:20:32.431159-05:
      DOI: 10.1002/asjc.1702
  • An Enhanced Coupling Nonlinear Tracking Controller for Underactuated 3D
           Overhead Crane Systems
    • Authors: Menghua Zhang; Xin Ma, Xuewen Rong, Rui Song, Xincheng Tian, Yibin Li
      Abstract: An enhanced coupling nonlinear tracking control method for an underactuated 3D overhead crane systems is set forth in the present paper. The proposed tracking controller guarantees a smooth start for the trolley and solves the problem of the payload swing angle amplitude increasing as the transferring distance gets longer for the regulation control methods. Different from existing tracking control methods, the presented control approach has an improved transient performance. More specifically, by taking the operation experience, mathematical analysis of the overhead crane system, physical constraints, and operational efficiency into consideration, we first select two desired trajectories for the trolley. Then, a new storage function is constructed by the introduction of two new composite signals, which increases the coupling behaviour between the trolley movement and payload swing. Next, a novel tracking control strategy is designed according to the derivation form of the aforementioned storage function. Lyapunov techniques and Barbalat's Lemma are used to demonstrate the stability of the closed-loop system without any approximation manipulations to the original nonlinear dynamics. Finally, some simulation and experiments are used to demonstrate the superior transient performance and strong robustness with respect to different cable lengths, payload masses, destinations, and external disturbances of the enhanced coupling nonlinear tracking control scheme.
      PubDate: 2017-10-23T10:10:46.552133-05:
      DOI: 10.1002/asjc.1683
  • Predictor Feedback Stabilization of Stochastic Linear Delayed Systems with
           Both Additive and Multiplicative Noises
    • Authors: Ali Javadi; Mohammad Reza Jahed-Motlagh, Ali-Akbar Jalali
      Abstract: In this paper we investigate memory control of stochastic linear delayed systems with both additive and multiplicative noises. A new formula is first presented to obtain the prediction vector from the system dynamics and then it is used for feedback to reduce the input delay in the original delayed system. To ensure the stability of closed-loop system, some matrix inequality conditions are given that in the case of feasibility provide the stabilizing gain of the predictor controller. The proposed method is applied to stochastic quarter-car model of an active suspension system to show the effectiveness of the approach.
      PubDate: 2017-10-23T10:10:31.301146-05:
      DOI: 10.1002/asjc.1657
  • Control of Grid Connected Photovoltaic Systems with Microinverters: New
           Theoretical Design and Numerical Evaluation
    • Authors: Abdelhafid Yahya; Hassan El Fadil, Mustapha Oulcaid, Leila Ammeh, Fouad Giri, Josep M. Guerrero
      Abstract: This paper addresses the problem of controlling grid connected photovoltaic (PV) systems that are driven with microinverters. The systems to be controlled consist of a solar panel, a boost dc–dc converter, a DC link capacitor, a single-phase full-bridge inverter, a filter inductor, and an isolation transformer. We seek controllers that are able to simultaneously achieve four control objectives, namely: (i) asymptotic stability of the closed loop control system; (ii) maximum power point tracking (MPPT) of the PV module; (iii) tight regulation of the DC bus voltage; and (iv) unity power factor (PF) in the grid. To achieve these objectives, a new multiloop nonlinear controller is designed using the backstepping design technique. A key feature of the control design is that it relies on an averaged nonlinear system model accounting, on the one hand, for the nonlinear dynamics of the underlying boost converter and inverter and, on the other, for the nonlinear characteristic of the PV panel. To achieve the MPPT objective, a power optimizer is designed that computes online the optimal PV panel voltage used as a reference signal by the PV voltage regulator. It is formally shown that the proposed controller meets all the objectives. This theoretical result is confirmed by numerical simulation tests.
      PubDate: 2017-10-23T04:51:12.412608-05:
      DOI: 10.1002/asjc.1704
  • Iterative Learning Control for Nonlinear Systems with Data Dropouts at
           Both Measurement and Actuator Sides
    • Authors: Yanqiong Jin; Dong Shen
      Abstract: This paper discusses the iterative learning control (ILC) for nonlinear systems under a general networked control structure, in which random data dropouts occur independently at both measurement and actuator sides. Both updating algorithms are proposed for the computed input signal at the learning controller and the real input signal at the plant, respectively. The system output is strictly proved to converge to the desired reference with probability one as the iteration number goes to infinity. A numerical simulation is provided to verify the effectiveness of the proposed mechanism and algorithms.
      PubDate: 2017-10-18T07:31:00.37189-05:0
      DOI: 10.1002/asjc.1656
  • Sliding Mode Disturbance Observer-based Motion Control for a Piezoelectric
           Actuator-based Surgical Device
    • Authors: Jun Yik Lau; Wenyu Liang, Hwee Choo Liaw, Kok Kiong Tan
      Abstract: This paper presents a sliding mode disturbance observer-based motion tracking control methodology. In particular, the methodology is applied to control a semi-automated hand-held ear surgical device for the treatment of otitis media with effusion. The proposed control methodology is utilised to deal with the undesirable effects in the motion system, such as non-linear dynamics, parametric uncertainties and external disturbances. It employs a proportional-derivative control scheme together with a sliding mode disturbance observer for rejecting the undesirable effects. The stability of the proposed control methodology is proven theoretically and its effectiveness is evaluated experimentally. In addition, promising motion tracking experimental results are shown, and it can be observed that the proposed approach offers more robust performance for controlling the hand-held surgical device and other similar instruments.
      PubDate: 2017-10-18T07:20:50.545724-05:
      DOI: 10.1002/asjc.1649
  • Adaptive Iterated Extended KALMAN Filter for Relative Spacecraft Attitude
           and Position Estimation
    • Authors: Kai Xiong; Chunling Wei
      Abstract: This paper presents a novel adaptive iterated extended Kalman filter (AIEKF) for relative position and attitude estimation, taking into account the influence of model uncertainty. Considering a nonlinear stochastic discrete-time system with unknown disturbance, the AIEKF algorithm adopts the Gauss-Newton iterative optimization steps to implement a maximum a posteriori (MAP) estimation, and the switch-mode combination technique is used to achieve the adaptive capability. The mean-square estimation error (MSE) of the state estimate is derived. It is proved that the AIEKF can yield a smaller MSE than that of the traditional extended Kalman filter (EKF) or iterated extended Kalman filter (IEKF). The performance advantage of the AIEKF is illustrated via Monte Carlo simulations on a typical relative position and attitude estimation application. Through comparisons in different scenarios, the presented algorithm is shown to improve adaptability and ensure estimation accuracy.
      PubDate: 2017-10-18T07:20:36.443585-05:
      DOI: 10.1002/asjc.1689
  • Adaptive Nonlinear Control of Reduced-Part three-Phase Shunt Active Power
    • Authors: Younes Abouelmahjoub; Fouad Giri, Abdelmajid Abouloifa, Fatima-Zahra Chaoui, Mohammed Kissaoui
      Abstract: The problem of controlling reduced-part three-phase shunt active power filters is addressed in the presence of nonlinear loads. The control objective is twofold: (i) compensation of the current harmonics and the reactive power absorbed by the nonlinear load in order to ensure a satisfactory power factor correction (PFC) at the grid-filter connection point; (2) regulation of the DC bus voltage at the inverter input. The considered control problem entails several difficulties including: (1) the high dimension and strong nonlinearity of the system; (ii) the numerous state variables that are inaccessible to measurements; (iii) the system parameter uncertainty. The problem is dealt with by designing a nonlinear adaptive controller with cascade structure including two control loops. The inner-loop regulator is designed using the Lyapunov technique to ensure the PFC objective, while the outer-loop involves a linear PI type control law for DC bus voltage regulation. The controller also includes an adaptive observer estimating the grid voltages and impedances parameters. The resulting control performances are formally analyzed using the averaging theory. Simulation results are presented illustrating the performances and the strong robustness of the proposed control strategy.
      PubDate: 2017-10-16T04:01:32.117176-05:
      DOI: 10.1002/asjc.1681
  • Learning Control of Robot Manipulators in Task Space
    • Authors: K. M. Dogan; E. Tatlicioglu, E. Zergeroglu, K. Cetin
      Abstract: Two important properties of industrial tasks performed by robot manipulators, namely, periodicity (i.e., repetitive nature) of the task and the need for the task to be performed by the end-effector, motivated this work. Not being able to utilize the robot manipulator dynamics due to uncertainties complicated the control design. In a seemingly novel departure from the existing works in the literature, the tracking problem is formulated in the task space and the control input torque is aimed to decrease the task space tracking error directly without making use of inverse kinematics at the position level. A repetitive learning controller is designed which “learns” the overall uncertainties in the robot manipulator dynamics. The stability of the closed-loop system and asymptotic end-effector tracking of a periodic desired trajectory are guaranteed via Lyapunov based analysis methods. Experiments performed on an in-house developed robot manipulator are presented to illustrate the performance and viability of the proposed controller.
      PubDate: 2017-10-16T04:01:20.526742-05:
      DOI: 10.1002/asjc.1648
  • State Space Constrained Iterative Learning Control for Robotic
    • Authors: Kaloyan Yovchev; Kamen Delchev, Evgeniy Krastev
      Abstract: Real-life work operations of industrial robotic manipulators are performed within a constrained state space. Such operations most often require accurate planning and tracking a desired trajectory, where all the characteristics of the dynamic model are taken into consideration. This paper presents a general method and an efficient computational procedure for path planning with respect to state space constraints. Given a dynamic model of a robotic manipulator, the proposed solution takes into consideration the influence of all imprecisely measured model parameters, making use of iterative learning control (ILC). A major advantage of this solution is that it resolves the well-known problem of interrupting the learning procedure due to a high transient tracking error or when the desired trajectory is planned closely to the state space boundaries. The numerical procedure elaborated here computes the robot arm motion to accurately track a desired trajectory in a constrained state space taking into consideration all the dynamic characteristics that influence the motion. Simulation results with a typical industrial robot arm demonstrate the robustness of the numerical procedure. In particular, the results extend the applicability of ILC in robot motion control and provide a means for improving the overall trajectory tracking performance of most robotic systems.
      PubDate: 2017-10-12T03:00:36.543553-05:
      DOI: 10.1002/asjc.1680
  • Characterization of Stochastic Mean-Field Type H− Index
    • Authors: Limin Ma; Yan Li, Tianliang Zhang
      Abstract: H− index of mean-field stochastic differential equations (SDE) is investigated in this paper. For systems with state- and input-dependent noise, we obtain a sufficient condition of H− index larger than some λ>0 via the solvability of differential Riccati equations (DRE). Especially, a necessary and sufficient condition is given for mean-field SDE with state-dependent noise, which generalize the corresponding results of classical stochastic systems to the mean-field stochastic models.
      PubDate: 2017-10-11T09:31:04.841734-05:
      DOI: 10.1002/asjc.1658
  • Event-Triggered Consensus of Nonlinear Multi-Agent Systems with Unknown
           External Disturbance
    • Authors: Tao Dong; Aijuan Wang
      Abstract: This paper addresses the consensus problem of nonlinear multi-agent systems with unknown external disturbance. First, a distributed observer is proposed to estimate the state and unknown disturbance of each agent simultaneously. Then, a novel event-triggered control scheme based on the agent state estimation and disturbance estimation is proposed. Unlike the existing strategies, our event-triggered conditions depend on agent state estimation and disturbance estimation, which are more effective and practical. Under this observer and control strategy, some sufficient conditions are derived to ensure the consensus of the multi-agent system with unknown external disturbance. Moreover, the Zeno-behavior of triggering time sequences is also excluded. Finally, a simulation example is given to verify the theoretical analysis.
      PubDate: 2017-10-09T10:01:19.119729-05:
      DOI: 10.1002/asjc.1682
  • Continuous-Action XCSR with Dynamic Reward Assignment Dedicated to Control
           of Black-Box Mechanical Systems
    • Authors: Saeed Hashemnia; Masoud Shariat Panahi, Mohammad Mahjoob
      Abstract: A real-value classifier system (CSR) is improved by the introduction of a continuous domain of actions to be employed for control of mechanical systems where there is no information concerning the system's mathematical model. To enable the classifier system to handle real-world control problems where continuous (non-discrete) actions are required, the exploitation of fuzzy membership functions is proposed. To cope with the dynamic system's delayed response due to its mass inertia, a dynamic reward assignment mechanism is incorporated into the proposed CSR. This allows the rapid calculation of the reward and hence enables the controller to be used in such real time applications. To demonstrate the efficiency of the developed enhanced CSR, it is employed as the controller to balance an unmanned bicycle, without using bicycle properties for the design process of the enhanced CSR. Simulation results show that in terms of overshoot and settling time, the proposed classifier system outperforms traditional XCSR as well as some of the more common balance-control strategies reported in the literature, as verified using ADAMS software.
      PubDate: 2017-10-06T12:05:33.217513-05:
      DOI: 10.1002/asjc.1659
  • Adaptive Output-Feedback Control of Nonlinear Systems with Multiple
    • Authors: Yaxin Huang; Yungang Liu
      Abstract: This paper addresses the global stabilization via adaptive output-feedback for a class of uncertain nonlinear systems. Remarkably, the systems under investigation are with multiple uncertainties: unknown control directions, unknown growth rates and unknown input bias, and can be used to describe more physical plants. Multiple uncertainties, which usually cannot be compensated by a sole compensation technique, may give rise to big technical difficulty for controller design. To overcome such difficulty and to achieve the global stabilization, a new adaptive output-feedback scheme is proposed in this paper, by flexibly combining Nussbaum-type function, tuning function technique and extended state observer. It is shown that, under the designed controller, the system states globally converge to zero. A simulation example on non-zero set-point regulation is given to demonstrate the effectiveness of the theoretical results.
      PubDate: 2017-09-29T11:39:25.96162-05:0
      DOI: 10.1002/asjc.1637
  • Exponential Stabilization of Switched Discrete-Time Systems with All
           Unstable Modes
    • Authors: Jiao Li; Zixiao Ma, Jun Fu
      Abstract: This paper studies the exponential stabilization of switched discrete-time systems whose subsystems are unstable. A new sufficient condition for the exponential stability of the class of systems is proposed. The result obtained is based on the determination of a lower bound of the maximum dwell time by virtue of the multiple Lyapunov functions method. The key feature is that the given stability condition does not need the value of the Lyapunov function to uniformly decrease at every switching instant. An example is provided to illustrate the effectiveness of the proposed result.
      PubDate: 2017-09-29T11:38:29.956257-05:
      DOI: 10.1002/asjc.1651
  • An I&I-Based Observer to Solve the Output-Feedback Synchronization Problem
           for a Class of Chaotic Systems
    • Authors: Carlos Aguilar-Ibañez; Eloísa García-Canseco, Rafael Martínez-Guerra, Juan Carlos Martínez-García, Miguel Santiago Suarez-Castañon
      Abstract: A novel robust observer, intended to solve the output-feedback chaos synchronization problem for the Master/Slave Configuration, is proposed here. Assuming that the given Master system belongs to a specific class of feedback-linearized systems, our solution is based on the well-known Immersion and Invariance (I&I) method. The proposed observer is devoted to the asymptotic estimation of the Master system's underlying dynamics, and its effectiveness is illustrated via computer-based simulations that involve both the so-called Duffing's oscillator and the Genesio & Tesi system.
      PubDate: 2017-09-29T11:35:54.758747-05:
      DOI: 10.1002/asjc.1650
  • Nonlinear Adaptive Model Predictive Control of Constrained Systems with
           Offset-Free Tracking Behavior
    • Authors: Bahareh Vatankhah; Mohammad Farrokhi
      Abstract: In this paper, a nonlinear model-based predictive control strategy for constrained systems based on an adaptive neural network (NN) predictor is proposed. The proposed controller is robust against the model uncertainties and external bounded disturbances. Moreover, it provides offset-free tracking behavior using the adaptive structure in the model. Based on the uncertainties bounds, the restriction of the system constraints causes robust feasibility and stability of the closed-loop system. It is shown that the output of the NN predictor converges to the system output. Moreover, offset-free behavior of the closed-loop system is investigated using the Lyapunov theorem. Simulation results show the effectiveness of the proposed method as compared to the recently proposed model predictive control methods in the literature.
      PubDate: 2017-09-28T09:35:39.983546-05:
      DOI: 10.1002/asjc.1655
  • ℓ2 Gain Estimation and Visualization of A Control Parameter Set in 3D
           Space Using Plant Response Data
    • Authors: Masami Saeki
      Abstract: In this paper, a novel parameter space approach that uses volume rendering is proposed to visualize controller parameter sets that consist of three controller parameters. An off-line design method for robust control using plant response data is also studied. A solution set with equal ℓ2 gain can be visualized as isosurfaces in three-dimensional space, and the designer can visually select an appropriate parameter. This numerical method is applicable to many practical specifications, in contrast to analytical methods based on solving equations. An estimation method based on the extension theorem and a method using bandpass filters are both considered as possible methods for estimating the ℓ2 gain of the sensitivity functions when using grid points on the order of tens of thousands to create the volume data.The former method is superior to the latter with respect to accuracy but impractical with respect to computational load. The latter method is hence practical, because the computing time is reduced to less than 0.05 s for about 300,000 grid points by parallel computation with a graphical processing unit.
      PubDate: 2017-09-28T09:31:39.104873-05:
      DOI: 10.1002/asjc.1647
  • Identification Recurrent Type 2 Fuzzy Wavelet Neural Network and L2-Gain
           Adaptive Variable Sliding Mode Robust Control of Electro-Hydraulic Servo
           System (EHSS)
    • Authors: Xiangjian Chen; Di Li, Xibei Yang, Yuecheng Yu
      Abstract: An electro-hydraulic servo system (EHSS) is a kind of system with the characteristics of time-variant, serious nonlinearity, parameter and structural uncertainty, and uncertain load disturbance in most cases. These characteristics make it very difficult to realize highly accurate control by conventional methods. In order to solve the above problems, this paper introduces a recurrent type 2 fuzzy wavelet neural network to approximate the unknown nonlinear functions of the dynamic systems through tuning by the desired adaptive law. Based on the identification by recurrent type 2 fuzzy wavelet neural network, a L2 gain design method, combining gain adaptive variable sliding mode control with H infinity control, is proposed for load disturbance, thereby accommodating uncertainties that are the main factors affecting system stability and accuracy in EHSS. In this algorithm, a recurrent type 2 fuzzy wavelet neural network is employed to evaluate the unknown dynamic characteristics of the system and gain adaptive variable sliding mode control to compensate for evaluating errors, and H infinity control to suppress the effect on system by load disturbance. The experiment results show that the proposed system L2 gain design method can make the system exhibit strong robustness to parameter variation and load disturbance.
      PubDate: 2017-09-25T07:55:32.237462-05:
      DOI: 10.1002/asjc.1643
  • New Augmented Lyapunov-Krasovskii Functional for Stability Analysis of
           Systems with Additive Time-Varying Delays
    • Authors: Liming Ding; Yong He, Min Wu, Qinggou Wang
      Abstract: This paper is concerned with stability analysis for continuous-time systems with additive time-varying delays in the Lyapunov-Krasovskii(L-K) framework. Firstly, in view of the relationships between the upper bounds of the two time-varying delays, a new augmented L-K functional is constructed by using the information of the two upper bounds. Secondly, the free-matrix-based integral inequality is used to estimate the derivative of the constructed L-K functional. Thirdly, a less conservative criterion is derived to assess stability. Finally, a numerical example is presented to demonstrate the effectiveness of the criterion.
      PubDate: 2017-09-22T02:16:20.345654-05:
      DOI: 10.1002/asjc.1641
  • Globally Stable Adaptive Dynamic Surface Control for Cooperative Path
           Following of Multiple Underactuated Autonomous Underwater Vehicles
    • Authors: Hao Wang; Yiping Li, Kaizhou Liu
      Abstract: The cooperative path following problem of multiple underactuated autonomous underwater vehicles (AUVs) involves two tasks. The first one is to force each AUV to converge to the desired parameterized path. The second one is to satisfy the requirement of a cooperative behavior along the paths. In this paper, both of the tasks have been further studied. For the first one, a simplified path following controller is proposed by incorporating the dynamic surface control (DSC) technique to avoid the calculation of derivatives of virtual control signals. Besides, in order to handle the uncertain dynamics, a new type of neural network (NN) adaptive controller is derived, and then an NN based energy-efficient path following controller is firstly proposed, which consists of an adaptive neural controller dominating in the neural active region and an extra robust controller working outside the neural active region. For the second one, in order to reduce the amount of communications between multiple AUVs, a distributed estimator for the reference common speed is firstly proposed as determined by the communications topology adopted, which means the global knowledge of the reference speed is relaxed for the problem of cooperative path following. The overall algorithm ensures that all the signals in the closed-loop system are globally uniformly ultimately bounded (GUUB) and the output of the system converges to a small neighborhood of the reference trajectory by properly choosing the design parameters. Simulation results validate the performance and robustness of the proposed strategy.
      PubDate: 2017-09-22T02:02:53.81665-05:0
      DOI: 10.1002/asjc.1646
  • Robust Constrained Model Predictive Control for Discrete-Time Uncertain
           System in Takagi-Sugeno's Form
    • Authors: Haofei Xie; Jun Wang, Xiaoming Tang
      Abstract: In this paper, we investigate a robust constrained model predictive control synthesis approach for discrete-time Takagi-Sugeno's (T-S) fuzzy system with structured uncertainty. The key idea is to determine, at each sampling time, a state feedback fuzzy predictive controller that minimizes the performance objective function in the infinite time horizon by solving a class of linear matrix inequalities (LMIs) optimization problem. To do this, the fuzzy predictive controller is designed on the basis of non-parallel distributed compensation (non-PDC) control law, relaxed stability conditions of the closed-loop fuzzy system are developed by employing an extended nonquadratic Lyapunov function and introducing additional slack and collection matrices. In addition, the presented approach is capable of ensuring the robust asymptotic stability as well as the recursive feasibility of the closed-loop fuzzy system. Simulations on a highly nonlinear continuous stirred tank reactor (CSTR) are eventually presented to demonstrate the effectiveness of the developed theoretical approach.
      PubDate: 2017-09-22T02:02:13.49513-05:0
      DOI: 10.1002/asjc.1603
  • New Results on Stabilization of Fractional-Order Nonlinear Systems via an
           LMI Approach
    • Authors: Mai Viet Thuan; Dinh Cong Huong
      Abstract: This paper considers the systematic design of robust stabilizing state feedback controllers for fractional-order nonlinear systems. By using the Lyapunov direct method and a recent result on the Caputo fractional derivative of a quadratic function, stabilizability conditions expressed in terms of linear matrix inequalities are derived. The controllers can then be derived by using existing computationally effective convex algorithms. Two numerical examples with simulation results are provided to demonstrate the effectiveness of our results.
      PubDate: 2017-09-19T09:00:35.647907-05:
      DOI: 10.1002/asjc.1644
  • On the Design of Event-Triggered Suboptimal Controllers for Nonlinear
    • Authors: Yazdan Batmani
      Abstract: In this paper, two suboptimal event-triggered control techniques are proposed for both the regulation and the tracking problems in a broad class of nonlinear networked control systems. The proposed techniques are based on the state-dependent Riccati equation (SDRE) methodology. In the case of the regulation problem, the asymptotic stability of the origin of the closed-loop system under the proposed event-triggered control law is investigated. In addition, for the tracking problem, it is proved that the tracking error between the system output and its desired trajectory converges asymptotically to zero under some mild conditions. It is shown that the proposed methods can considerably reduce the information exchange between the controller and the actuator. Due to the implementation procedures of the proposed techniques, no Zeno behavior is occurred. Three numerical simulations are provided to demonstrate the design procedure and the flexibility of the proposed event-triggered control techniques.
      PubDate: 2017-09-19T09:00:28.432287-05:
      DOI: 10.1002/asjc.1632
  • FTESO-Based Finite Time Control for Underactuated System Within a Bounded
    • Authors: Hongbin Wang; Zhen Zhou, Ce Hao, Zhongquan Hu, Wei Zheng
      Abstract: Finite time control problem is investigated for a class of underactuated systems with uncertainties and external disturbances. For the sake of expanding control region furthest within a bound input, finite time extended state observer (FTESO) and a novel adaptive terminal sliding mode (ATSM) controller are applied to improve the stability performance of system. Compared to the general extended state observer (ESO), FTESO makes use of fractional powers to reduce the estimation errors to zero in finite time. The coordinate transformation is made for more degrees of design freedom. Rigorous analysis of finite time convergence results has been performed through Lyapunov theory and sufficient conditions are provided for the observer/controller-design. Finally, simulation results on the Rotating Inverted Pendulum are given to demonstrate the effectiveness of the proposed controller and observer.
      PubDate: 2017-09-19T08:56:30.341715-05:
      DOI: 10.1002/asjc.1624
  • Control of two Electrical Plants
    • Authors: José de Jesús Rubio; Jesus Lopez, Jaime Pacheco, Rodrigo Encinas
      Abstract: In this paper, a controller is recommended for the regulation of two electrical plants. Since electrical plants generate electricity all the time, the regulation to get that all the plant states reach constant behaviors is important. Two main characteristics of the introduced method are: (i) it is based in the separation of the plant model equations, only some model equations are chosen for the regulation while the other model equations are ignored, it avoids the difficulty in the consideration of the full plant model; (ii) the Lyapunov strategy is employed to analyze the stability of the selected model equations in the electrical plant, it lets to ensure the regulation purpose. The advised method is applied in a gas turbine and a wind turbine for the electricity generation.
      PubDate: 2017-09-15T12:15:38.185053-05:
      DOI: 10.1002/asjc.1640
  • Sum-of-Squares-Based Finite-Time Adaptive Sliding Mode Control of
           Uncertain Polynomial Systems With Input Nonlinearities
    • Authors: Mohammad Mehdi Mardani; Navid Vafamand, Mostafa Shokrian Zeini, Mokhtar Shasadeghi, Alireza Khayatian
      Abstract: This paper proposes a novel adaptive sliding mode control (ASMC) for a class of polynomial systems comprising uncertain terms and input nonlinearities. In this approach, a new polynomial sliding surface is proposed and designed based on the sum-of-squares (SOS) decomposition. In the proposed method, an adaptive control law is derived such that the finite-time reachability of the state trajectories in the presence of input nonlinearity and uncertainties is guaranteed. To do this, it is assumed that the uncertain terms are bounded and the input nonlinearities belong to sectors with positive slope parameters. However, the bound of the uncertain terms is unknown and adaptation law is proposed to effectively estimate the uncertainty bounds. Furthermore, based on a novel polynomial Lyapunov function, the finite-time convergence of the sliding surface to a pre-chosen small neighborhood of the origin is guaranteed. To eliminate the time derivatives of the polynomial terms in the stability analysis conditions, the SOS variables of the Lyapunov matrix are optimally selected. In order to show the merits and the robust performance of the proposed controller, chaotic Chen system is provided. Numerical simulation results demonstrate chattering reduction in the proposed approach and the high accuracy in estimating the unknown parameters.
      PubDate: 2017-09-15T12:11:01.295402-05:
      DOI: 10.1002/asjc.1625
  • Design of Optimal Petri Net Supervisors for Flexible Manufacturing Systems
           via Weighted Inhibitor Arcs
    • Authors: XuYa Cong; Chao Gu, Murat Uzam, YuFeng Chen, Abdulrahman M. Al-Ahmari, NaiQi Wu, MengChu Zhou, ZhiWu Li
      Abstract: This paper develops an approach to the design of an optimal Petri net supervisor that enforces liveness to flexible manufacturing systems. The supervisor contains a set of observer places with weighted inhibitor arcs. An observer place with a weighted inhibitor arc is used to forbid a net from yielding an illegal marking by inhibiting the firing of a transition at a marking while ensuring that all legal markings are preserved. A marking reduction technique is presented to decrease the number of considered markings, which can dramatically lower the computational burden of the proposed approach. An integer linear program is presented to simplify the supervisory structure by minimizing the number of observer places. Finally, several examples are used to shed light on the proposed approach which can lead to an optimal supervisor for the net models that cannot be optimally controlled via pure Petri net supervisors.
      PubDate: 2017-09-15T12:10:58.135926-05:
      DOI: 10.1002/asjc.1583
  • Robust H∞ Control of Discrete-time Singular Systems via Integral
           Sliding Surface
    • Authors: Jianjun Bai; Renquan Lu, Zhengguang Wu, Ridong Zhang, Xiaodong Zhao, Anke Xue
      Abstract: In this paper, the sliding mode control for a class of uncertain discrete-time singular system with H∞ performance constraint is studied. By taking the singular matrix E into consideration, a new type of integral sliding mode surface is firstly introduced, based on which a sufficient condition is derived to guarantee the sliding mode dynamics admissible with a given γ-level disturbance attenuation of the unmatched disturbance. A controller law is also given to keep the system trajectory staying in a neighborhood of the ideal sliding surface. Finally, a numerical example is given to show the effectiveness of the proposed approach.
      PubDate: 2017-09-15T12:10:24.59444-05:0
      DOI: 10.1002/asjc.1638
  • Neural Network Dynamic Surface Backstepping Control for the Speed and
           Tension System of Reversible Cold Strip Rolling Mill
    • Authors: Le Liu; Yu Han, Yiming Fang, Minghao Lin, Nuan Shao
      Abstract: To weaken the influences of uncertainties and system coupling items on the coordinated tracking control performance of the speed and tension system of a reversible cold strip rolling mill, a control strategy is proposed based on nonlinear disturbance observers (NDOs), dynamic surface backstepping control, and neural network adaptive approximation. First, the transformation form of the system model is given, and then NDOs are developed to counteract the unmatched uncertainties. Next, controllers for the speed and tension system are presented by combining backstepping with dynamic surface control. Again, the neural network adaptive method is used to approximate the matched uncertainties of the system, and the approximation values are introduced into the designed controllers for compensation. Finally, simulation research is carried out on the speed and tension system of a 1422 mm reversible cold strip rolling mill by using the actual data, and the results show the validity of the proposed control strategy in comparison with the decentralized overlapping control strategy.
      PubDate: 2017-09-15T11:55:29.498456-05:
      DOI: 10.1002/asjc.1628
  • Stabilization of Hybrid Systems by Feedback Control Based on Discrete-Time
           State and Mode Observations
    • Authors: Yuyuan Li; Jianqiu Lu, Xuerong Mao, Qinwei Qiu
      Abstract: Recently, a kind of feedback control based on discrete-time state observations was proposed to stabilize continuous-time hybrid stochastic systems in the mean-square sense. We find that the feedback control there still depends on the continuous-time observations of the mode. However, it usually costs to identify the current mode of the system in practice. So we can further improve the control to reduce the control cost by identifying the mode at discrete times when we make observations for the state. In this paper, we aim to design such a type of feedback control based on the discrete-time observations of both state and mode to stabilize the given hybrid stochastic differential equations (SDEs) in the sense of mean-square exponential stability. Moreover, a numerical example is given to illustrate our results.
      PubDate: 2017-04-26T17:50:58.567335-05:
      DOI: 10.1002/asjc.1515
  • Performance Improvement of Fuel Cells Using Perturbation-Based Extremum
           Seeking and Model Reference Adaptive Control
    • Authors: Reza Dadkhah Tehrani; Faridoon Shabani
      Abstract: Nowadays, fuel cells (FCs) are considered suitable alternative sources for electrical energy applications. One major challenge encountered in FCs is relevant to the performance of the maximum power point tracking (MPPT) under FC parameter changes and load variations. This challenge is due to the nonlinearity and time-varying dynamics of FC systems. In this paper, the MPPT is studied in a system composed of a FC and a DC-DC converter. To improve the performance of the MPPT, application of perturbation-based extremum seeking (PES) and model reference adaptive control (MRAC) is proposed. This control scheme can efficiently handle the uncertainties in the FC as well as the load, through two control levels. The first level is PES utilized to adjust the duty cycle of the DC-DC converter; and the second level is MRAC employed to achieve the desired dynamic response. Using the proposed control strategy, design and analysis of the control levels can be realized independently, which results in easy implementation. This is achieved due to considerable differences between the time constants of the control levels. The simulation results are utilized to confirm the effectiveness of the proposed scheme in response to the variations of FC parameters and load. Also, comparative studies with a combination of PES and PID controller are provided in the simulation.
      PubDate: 2017-04-26T10:35:52.254896-05:
      DOI: 10.1002/asjc.1519
  • Disturbance Observer-Based Elegant Anti-Disturbance Control for Stochastic
           Systems with Multiple Disturbances
    • Authors: Linqing Zhang; Xinjiang Wei, Huifeng Zhang
      Abstract: Disturbance observer-based elegant anti-disturbance control (DOBEADC) scheme is proposed for a class of stochastic systems with nonlinear dynamics and multiple disturbances. The stochastic disturbance observer based on pole placement is constructed to estimate disturbance which is generated by an exogenous system. Then, composite DOBC and H∞ controller is designed to guarantee the composite system is mean-square stable and its H∞performance satisfies a prescribed level. Finally, simulations on an A4D aircraft model show the effectiveness of the proposed approaches.
      PubDate: 2017-04-21T07:52:55.441863-05:
      DOI: 10.1002/asjc.1514
  • Adaptive Backstepping Control of Six-Phase PMSM Using Functional Link
           Radial Basis Function Network Uncertainty Observer
    • Authors: Faa-Jeng Lin; Shih-Gang Chen, I-Fan Sun
      Abstract: An adaptive backstepping control (ABSC) using a functional link radial basis function network (FLRBFN) uncertainty observer is proposed in this study to construct a high-performance six-phase permanent magnet synchronous motor (PMSM) position servo drive system. The dynamic model of a field-oriented six-phase PMSM position servo drive is described first. Then, a backstepping control (BSC) system is designed for the tracking of the position reference. Since the lumped uncertainty of the six-phase PMSM position servo drive system is difficult to obtain in advance, it is very difficult to design an effective BSC for practical applications. Therefore, an ABSC system is designed using an adaptive law to estimate the required lumped uncertainty in the BSC system. To further increase the robustness of the six-phase PMSM position servo drive, an FLRBFN uncertainty observer is proposed to estimate the lumped uncertainty of the position servo drive. In addition, an online learning algorithm is derived using Lyapunov stability theorem to learn the parameters of the FLRBFN online. Finally, the proposed position control system is implemented in a 32-bit floating-point DSP, TMS320F28335. The effectiveness and robustness of the proposed intelligent ABSC system are verified by some experimental results.
      PubDate: 2017-04-21T06:39:15.318482-05:
      DOI: 10.1002/asjc.1521
  • Rapid Exponential Stabilization of a 1-D Transmission Wave Equation with
           In-domain Anti-damping
    • Authors: Fathi Hassine
      Abstract: We consider the problem of pointwise stabilization of a one-dimensional wave equation with an internal spatially varying anti-damping term. We design a feedback law based on the backstepping method and prove exponential stability of the closed-loop system with a desired decay rate.
      PubDate: 2017-04-21T06:22:14.769849-05:
      DOI: 10.1002/asjc.1509
  • A Numerical Approximation-Based Controller for Mobile Robots with Velocity
    • Authors: Mario E. Serrano; Sebastián A. Godoy, Santiago Rómoli, Gustavo J.E. Scaglia
      Abstract: In this paper the problem of trajectory tracking considers that the values of the control actions do not exceed a maximum allowable value and the zero convergence of tracking errors is demonstrated. The control law is based on a linear algebra approach. First, the desired trajectories of some state variables are determined by analyzing the conditions for a system of linear equations to have an exact solution. Therefore, the control signals are obtained by solving the system of linear equations. The optimal controller parameters are selected through nonlinear programming so as to prevent the saturation of the control actions. Experimental results are presented and discussed, demonstrating the controller's good performance. Finally, the performance of the proposed controller is compared with a fuzzy controller, and all the results are validated through experimental laboratory tests.
      PubDate: 2017-04-11T11:05:49.629631-05:
      DOI: 10.1002/asjc.1522
  • Adaptive Robust Output Tracking Control of Uncertain Nonlinear Cascade
           Systems with Disturbance and Multiple Uknown Time-Varying Delays
    • Authors: Hossein Chehardoli; Ali Ghasemi
      Abstract: In this paper, an adaptive robust controller is designed for a class of uncertain nonlinear cascade systems with multiple time-varying delays under external disturbance. It is assumed that multiple time-varying delays are not exactly known and, therefore, the delayed terms must not appear in the adaptation and control laws. Accordingly, by using a Lyapunov-Krasovskii function, delays are deleted from the adaptation and control laws. A controller based on an adaptive backstepping approach is designed to assure the global asymptotic tracking of the desired output and boundedness of the other states. The proposed controller is proved to be robust against unknown time-varying delays and external disturbances applying to the system. Simulation results are provided to show the effectiveness of the proposed approach.
      PubDate: 2017-04-04T07:01:06.931632-05:
      DOI: 10.1002/asjc.1504
  • Three-Axis Global Magnetic Attitude Control of Earth-Pointing Satellites
           in Circular Orbit
    • Authors: Dipak Giri; Bijoy Mukherjee, Bidul T N, Manoranjan Sinha
      Abstract: This paper addresses the controllability and global stability issues of a magnetically actuated satellite in the geomagnetic field. The variation of the geomagnetic field along the orbit, which is time varying in nature, makes the dynamics of the satellite time varying also. Sufficient conditions for controllability of such a time varying magnetic attitude control system are given. As a major contribution, it is proven that the three-axis controllability of the spacecraft actuated by the magnetic actuators is possible and it does not depend on the initial angular velocity of the spacecraft. Global controllability is a precursor to global stability. Therefore, exponential stability for an arbitrarily high initial angular velocity and an arbitrary initial orientation is proven next for a proportional-derivative control law using averaging theory. It is also proven that even an iso-inertial satellite can be stabilized using the time invariant feedback control, which was hitherto not possible, even using time variant conventional control. Simulation results are presented under different initial orientations and angular velocities of the satellite in the presence of favorable and unfavorable gravity gradient torques to validate the proposed control method.
      PubDate: 2017-03-31T09:25:36.605094-05:
      DOI: 10.1002/asjc.1506
  • Minimum Energy Control of Fractional Descriptor Discrete-Time Linear
           Systems with Bounded Inputs Using The DRAZIN Inverse
    • Authors: Tadeusz Kaczorek
      Abstract: The Drazin inverse of matrices is applied to solve the minimum energy control problem of fractional descriptor discrete-time linear systems with bounded inputs. Necessary and sufficient conditions for the reachability of fractional descriptor linear systems are established. The minimum energy control problem for the fractional descriptor systems with bounded inputs is formulated and solved. A procedure for the computation of the optimal inputs sequence and the minimal value of the performance index is proposed.
      PubDate: 2017-03-29T12:15:33.309721-05:
      DOI: 10.1002/asjc.1510
  • Consensus Control of Fractional-Order Systems Based on Delayed State
           Fractional Order Derivative
    • Authors: Xueliang Liu; Zhi Zhang, Huazhu Liu
      Abstract: In this paper, the delayed state fractional order derivative (DSFOD) is introduced into the existing traditional consensus protocol aiming to improve the robustness of fractional-order multi-agent systems against communication time delay. Both of communication channels with time-delay and without time-delay cases are considered. Based on the frequency-domain analysis and algebraic graph theory, it is shown that properly choosing the intensity of DSFOD can improve the robustness of fractional-order multi-agent systems against communication delay. Finally, a simulated example with simulations is presented to confirm the correctness and effectiveness of the theoretical results.
      PubDate: 2017-03-29T09:45:36.366043-05:
      DOI: 10.1002/asjc.1493
  • Observer-based Fault Estimators Using Iterative Learning Scheme for Linear
           Time-delay Systems with Intermittent Faults
    • Authors: Li Feng; Ke Zhang, Yi Chai, Zhimin Yang, Shuiqing Xu
      Abstract: This paper deals with the fault estimation problem for a class of linear time-delay systems with intermittent fault and measurement noise. Different from existing observer-based fault estimation schemes, in the proposed design, an iterative learning observer is constructed by using the integrated errors composed of state predictive error and tracking error in the previous iteration. First of all, Lyapunov function including the information of time delay is proposed to guarantee the convergence of system output. Subsequently, a novel fault estimation law based on iterative learning scheme is presented to estimate the size and shape of various fault signals. Upon system output convergence analysis, we proposed an optimal function to select appropriate learning gain matrixes such that tracking error converges to zero, simultaneously to ensure the robustness of the proposed iterative learning observer which is influenced by measurement noise. Note that, an improved sufficient condition for the existence of such an estimator is established in terms of the linear matrix inequality (LMI) by the Schur complements and Young relation. In addition, the results are both suit for the systems with time-varying delay and the systems with constant delay. Finally, three numerical examples are given to illustrate the effectiveness of the proposed methods and two comparability examples are provided to prove the superiority of the algorithm.
      PubDate: 2017-03-20T04:50:51.890483-05:
      DOI: 10.1002/asjc.1491
  • Synthesis of Mixed Objective Output Feedback Robust Model Predictive
    • Authors: Wei Jiang; Hongli Wang, Jinghui Lu, Weiwei Qin, Guangbin Cai
      Abstract: Aiming at the constrained polytopic uncertain system with energy-bounded disturbance and unmeasurable states, a novel synthesis scheme to design the output feedback robust model predictive control(MPC)is put forward by using mixed H2/H∞ design approach. The proposed scheme involves an offline design of a robust state observer using linear matrix inequalities(LMIs)and an online output feedback robust MPC algorithm using the estimated states in which the desired mixed objective robust output feedback controllers are cast into efficiently tractable LMI-based convex optimization problems. In addition, the closed-loop stability and the recursive feasibility of the proposed robust MPC are guaranteed through an appropriate reformulation of the estimation error bound (EEB). A numerical example subject to input constraints illustrates the effectiveness of the proposed controller.
      PubDate: 2017-03-20T04:46:03.799864-05:
      DOI: 10.1002/asjc.1494
  • Almost Sure Practical Exponential Stability of Nonlinear Disturbed
           Stochastic Systems with Guaranteed Decay Rate
    • Authors: Asma Barbata; Michel Zasadzinski, Ridha Chatbouri, Harouna Souley Ali, Hassani Messaoud
      Abstract: In this paper, we consider nonlinear stochastic differential equations driven by multiplicative noises and affected by exogenous disturbances. Sufficient conditions are investigated for almost sure practical exponential stability of the non trivial solutions of these equations. A lower bound of the decay rate of these solutions is guaranteed.
      PubDate: 2017-02-17T09:10:44.498833-05:
      DOI: 10.1002/asjc.1472
  • Controller Reset Strategy for Anti-Windup Based on Switching L2 Gain
    • Authors: K. Suyama; N. Sebe
      Pages: 1877 - 1890
      Abstract: When the calculated value of a control input approaches its limitations, resets of controllers are often used to prevent windup. However, an automatic reset should only be performed after confirmation that it will not adversely affect the transient performance and lead to another windup. In this study, we apply a switching L2 gain analysis to a more appropriate evaluation of transient responses after a reset in order to propose an improved strategy for the automatic resets of controllers, such that windup does not accompany resets.
      PubDate: 2017-06-07T06:24:44.527418-05:
      DOI: 10.1002/asjc.1530
  • Robust Stochastic Stability and H∞ Control for Uncertain Singular
           Markovian Jump Systems with Multiplicative Noise
    • Authors: Yong Zhao; Weihai Zhang, Jianwei Xia, Tianliang Zhang
      Pages: 1891 - 1904
      Abstract: This paper focuses on the problems of robust stability and stabilization and robust H∞ control for uncertain singular Markovian jump systems with (x,v)-dependent noise. The parameter uncertainties appearing in state, input, disturbance as well as diffusion terms are assumed to be time-varying but norm-bounded. Based on the approach of generalized quadratic stability, the memoryless state feedback controller is designed for the robust stabilization problem, which ensures that the resulting closed-loop system has an impulse-free solution and is asymptotically stable in the mean square. Furthermore, the results of robust H∞ control problem are derived. The desired state feedback H∞ controller is presented, which not only meets the requirement of robust stabilization but also satisfies a prescribed H∞ performance level. The obtained results are formulated in terms of strict LMIs. What we have obtained can be viewed as corresponding extensions of existing results on uncertain singular systems. A numerical example is finally given to demonstrate the application of the proposed method.
      PubDate: 2017-06-09T04:35:44.86579-05:0
      DOI: 10.1002/asjc.1543
  • Critical Issues on Kalman Filter with Colored and Correlated System Noises
    • Authors: Zebo Zhou; Jin Wu, Yong Li, Chen Fu, Hassen Fourati
      Pages: 1905 - 1919
      Abstract: The Kalman filtering (KF) is optimal under the assumption that both process and observation noises are independent white Gaussian noise. However, this assumption is not always satisfied in real-world navigation campaigns. In this paper, two types of KF methods are investigated, i.e. augmented KF (AKF) and the second moment information based KF (SMIKF) with colored system noises, including process and observation noises. As a popular noise-whitening method, the principle of AKF is briefly reviewed for dealing with the colored system noises. The SMIKF method is developed for the colored and correlated system noises, which directly compensates for the covariance through stochastic model in the sense of minimum mean square error. To accurately implement the SMIKF, a refined SMIKF is further derived regarding the continuous-time dynamic model rather than the discrete one. The computational burdens of the proposed SMIKF along with representative methods are analyzed and compared. The simulation results demonstrate the performances of proposed methods.
      PubDate: 2017-06-22T08:21:10.122751-05:
      DOI: 10.1002/asjc.1545
  • An Improved Parameterized Controller Reduction Technique via New Frequency
           Weighted Model Reduction Formulation
    • Authors: Ahmad Jazlan; Pantazis Houlis, Victor Sreeram, Roberto Togneri
      Pages: 1920 - 1930
      Abstract: In this paper, an improved parameterized controller reduction technique via a new frequency weighted model reduction formulation is developed for the feedback control of MIMO discrete time systems particularly for non-unity feedback control system configurations which have the controller located in the feedback path. New frequency weights which are a function of a free parameter matrix are derived based on a set of equivalent block diagrams and this leads to a generalized double sided frequency weighted model reduction formulation. Solving this generalized double sided frequency weighted model reduction problem for various values of the free parameter results in obtaining controllers which correspond to each value of the free parameter. It is shown that the proposed formulation has a useful characteristic such that selecting a controller which corresponds to a large value of the free parameter results in obtaining an optimal reduced order controller and using this optimal reduced order controller in a closed loop system results in significant reduction in the infinity norm of the approximation error between the original closed loop system and the closed loop system which uses an optimal reduced order controller (when compared to existing frequency weighted model reduction methods).
      PubDate: 2017-06-14T08:25:24.982147-05:
      DOI: 10.1002/asjc.1559
  • Uncertain Optimal Control Approach for CO2 Mitigation Problem
    • Authors: Linxue Sheng; Yuanguo Zhu, Hongyan Yan, Kai Wang
      Pages: 1931 - 1942
      Abstract: The new types of uncertain control approaches based on the critical value criterion and chance criterion are respectively introduced to deal with multi-stage dynamic optimization problems in the presence of target constraints. Integrating the method of dynamic programming with the viability approach, the solving procedure of the optimal control sequence is provided. As a case study, a cost-effectiveness problem of mitigation policies for uncertain carbon dioxide emissions is analyzed and numerically computed to illustrate the proposed approaches.
      PubDate: 2017-05-12T06:41:28.303816-05:
      DOI: 10.1002/asjc.1524
  • Dynamical Analysis of a Tri-Neuron Fractional Network
    • Authors: Cheng-dai Huang; Jin-de Cao, Min Xiao, Ahmed Alsaedi, Fuad E. Alsaadi, Tasawar Hayat
      Pages: 2042 - 2050
      Abstract: The present paper concerns with the dynamics of a fractional neural network involving three neurons. Firstly, the bifurcation point is identified for which Hopf bifurcations may occur by taking the system parameter as a bifurcation parameter via the stability analysis of fractional systems. It is indicated that the system parameter can significantly affect the dynamical properties of such network. Secondly, the impact of the order on the bifurcation point is carefully examined. It is found that the occurrence of bifurcation is delayed as the order increases as long as the other system parameters are established. Finally, a numerical example is exploited to verify the efficiency of theoretical results.
      PubDate: 2017-05-24T05:01:56.604642-05:
      DOI: 10.1002/asjc.1527
  • Observer-Based Piecewise Fault-Tolerant Control for Discrete-Time
           Nonlinear Dynamic Systems
    • Authors: Liheng Chen; Xianlin Huang, Ming Liu
      Pages: 2051 - 2061
      Abstract: This paper is concerned with the fault-tolerant control (FTC) problem against simultaneous actuator and sensor fault for discrete-time nonlinear systems. The nonlinear plant is represented by Takagi–Sugeno (T–S) fuzzy dynamic models with disturbance and measurement noise. In this work, the original plant is augmented into a descriptor system, where the state and fault are assembled into a new state vector. Based on piecewise quadratic Lyapunov functions, a new T-S fuzzy fault-tolerant observer is designed such that both the actuator and sensor faults can be estimated asymptotically. Then, a piecewise observer-based FTC approach is developed to stabilize the resulting closed-loop fault system. Finally, a practical example of the truck-trailer model is presented to illustrate the effectiveness of the proposed method.
      PubDate: 2017-06-14T08:30:27.355409-05:
      DOI: 10.1002/asjc.1541
  • Synchronization of Complex Networks with Coupled and Self-Feedback Delays
           Via Aperiodically Intermittent Strategy
    • Authors: Mei Liu; Zhiyong Yu, Haijun Jiang, Cheng Hu
      Pages: 2062 - 2075
      Abstract: In this paper, we concern the exponential synchronization problem for hybrid-coupled delayed dynamical networks via aperiodically intermittent control. Different from previous works, the delayed coupling term considered here contains the transmission delay and self-feedback delay, and the intermittent control can be aperiodic. By utilizing a different technique compared with some previous results, several useful criteria are derived analytically to realise exponential synchronization for a class of coupled complex network. As a special case, some sufficient conditions ensuring the exponential synchronization for a class of coupled neural network are obtained. Finally, a numerical example is given to demonstrate the validness of the proposed scheme.
      PubDate: 2017-08-25T11:45:33.159638-05:
      DOI: 10.1002/asjc.1577
  • Consensus of Fractional Multi-Agent Systems Using Distributed Adaptive
    • Authors: Guojian Ren; Yongguang Yu
      Pages: 2076 - 2084
      Abstract: This paper is concerned with the adaptive consensus problem of fractional multi-agent systems for both the linear and nonlinear cases. Distributed adaptive protocols are designed, respectively, for linear and nonlinear fractional multi-agent systems, under which consensus is achieved for any undirected connected communication graph without using any global information. Furthermore, the leader-following problem is studied as an extension. Finally, two numerical examples are given to demonstrate the effectiveness of the obtained results.
      PubDate: 2017-08-24T09:42:41.130451-05:
      DOI: 10.1002/asjc.1589
  • Robust Output Feedback Model Predictive Control: A Stochastic Approach
    • Authors: Mohammadali Mohammadkhani; Farhad Bayat, Ali Akbar Jalali
      Pages: 2085 - 2096
      Abstract: This paper addresses the robust explicit model predictive control scheme for linear systems with input and output constraint in the presence of disturbances and noise. Conditions for disturbance rejection are established by incorporating a full state/disturbance observer. The separation principle is applied to design an optimal observer in the unconstrained problem. Then, an efficient algorithm is developed to explicitly design observer gains by minimizing a quadratic performance criterion. It is shown that the solution includes a set of regions with piecewise affine functions of the state and reference vectors and a set of regions with optimal observers. In the proposed method, two sets of partitions associated with the control law and the observer gains are obtained. Therefore, the online computation includes finding the active regions of both observer and control law partitions in which the current state is located. The proposed technique is particularly attractive for a wide range of practical problems where the exact model of the actual system is not available.
      PubDate: 2017-07-19T07:45:47.25895-05:0
      DOI: 10.1002/asjc.1575
  • Optimal Control Problem for Risk-Sensitive Mean-Field Stochastic Delay
           Differential Equation with Partial Information
    • Authors: Heping Ma; Bin Liu
      Pages: 2097 - 2115
      Abstract: This paper deals with the risk-sensitive control problem for mean-field stochastic delay differential equations (MF-SDDEs) with partial information. Firstly, under the assumptions that the control domain is not convex and the value function is non-smooth, we establish a stochastic maximum principle (SMP). Then, by means of Itô's formula and some continuous dependence, we prove the existence and uniqueness results for another type of MF-SDDEs. Meanwhile, the verification theorem for the MF-SDDEs is obtained by using a clever construction of the Hamiltonian function. Finally, based on our verification theorem, a linear-quadratic system is investigated and the optimal control is also derived by the stochastic filtering technique.
      PubDate: 2017-07-05T09:35:37.893473-05:
      DOI: 10.1002/asjc.1570
  • Sliding Mode Control for an Inhomogeneous Heat Equation with Global
    • Authors: Shuang Zhang
      Pages: 2116 - 2126
      Abstract: In this paper, an inhomogeneous heat equation with distributed load is controlled, on the basis of an infinite dimensional generalization of sliding-mode control method. The control law is designed so that: (i) the temperature can track a desired reference signal, and (ii) the temperature can remain in a constrained region. We show that, with the designed control, the tracking error is bounded stable without violation of the constraint. The stability is proved under the designed control law. Numerical simulations are given to illustrate the effectiveness of the designed control law.
      PubDate: 2017-08-24T09:42:08.269562-05:
      DOI: 10.1002/asjc.1607
  • An Efficient on-Line Parameter Identification Algorithm for Nonlinear
           Servomechanisms with an Algebraic Technique for State Estimation
    • Authors: Roger Miranda-Colorado; Javier Moreno-Valenzuela
      Pages: 2127 - 2142
      Abstract: This paper presents a methodology for on-line closed-loop identification of a class of nonlinear servomechanisms. First, a system is defined with the same structure as the actual servomechanism, but using time-varying estimated parameters. No coupling between the actual and the estimation systems is present. Position, velocity and acceleration errors, defined as the difference of the actual respective signals and the signals coming from the estimation system, are required in the identification method. Then, a recursive algorithm for on-line identification of the system parameters is derived from a cost function depending on a linear combination of all the estimation errors. Velocity and acceleration estimates, required in the proposed parameter identification algorithm, are obtained by using an algebraic methodology. The identification algorithm is compared by means of real-time experiments with an on-line least squares algorithm with forgetting factor and an off-line least squares algorithm with data preprocessing. Experimental results show that the proposed approach has a performance comparable to that obtained with the off-line least squares algorithm, but with the advantage of avoiding any preprocessing.
      PubDate: 2017-05-25T08:35:47.800662-05:
      DOI: 10.1002/asjc.1511
  • Stabilization of Time-Varying and Disturbed Complex Dynamical Networks
           with Different-Dimensional Nodes and Uncertain Nonlinearities
    • Authors: Lili Zhang; Youfa Lei, Yinhe Wang, Baoying Chen
      Pages: 2143 - 2154
      Abstract: This paper investigates the stabilization problem for time-varying and disturbed complex dynamical networks (CDNs) with different-dimensional nodes and uncertain nonlinearities. To be consistent with the properties of real-world networks, both the disturbances of our networks and the nonlinear structures of the nodes permit are completely unknown but bounded. Furthermore, the norm bounds of the uncertain nonlinearities and disturbances (NBUND) are applied to design the stabilization controllers. When the NBUND are known in advance, some decentralized state feedback controllers are proposed to stabilize our networks. And when they are unknown, adaptive decentralized stabilization schemes are brought forward for our network models. The effectiveness and feasibility of our theoretical results are verified by two simulation examples.
      PubDate: 2017-05-08T04:38:45.341457-05:
      DOI: 10.1002/asjc.1513
  • Distributed Adaptive Event-Triggered Control for Leader-Following
           Consensus of Multi-Agent Systems
    • Authors: Xiu You; Changchun Hua, Xinping Guan
      Pages: 2155 - 2164
      Abstract: This paper studies the leader-following consensus problem for Lipschitz nonlinear multi-agent systems using novel event-triggered controllers. A distributed adaptive law is introduced for the event-based control strategy design such that the proposed controllers are independent of system parameters and only use the relative states of neighboring agents, and hence are fully distributed. Due to the introduction of an event-triggered control scheme, the controller of the agent is only triggered at it's own event times, and thus reduces the amount of communication between controller and actuator and lowers the frequency of controller updates in practice. Based on a quadratic Lyapunov function, the event condition which uses only neighbor information and local computation at trigger instants is established. Infinite triggers within a finite time are also verified to be impossible. The effectiveness of the theoretical results are illustrated through simulation examples.
      PubDate: 2017-05-10T08:40:36.080358-05:
      DOI: 10.1002/asjc.1516
  • New Bounded Real Lemma Formulation and H∞ Control for
           Continuous-Time Descriptor Systems
    • Authors: M. Chadli; P. Shi, Z. Feng, J. Lam
      Pages: 2192 - 2198
      Abstract: This note proposes a new bounded real lemma, involving slack variables, for continuous-time descriptor systems. The derived result gives necessary and sufficient admissibility conditions in strict linear matrix inequality form. Then, an H∞ control is designed for the underlying systems. The work in this paper extends the results for discrete-time descriptor systems to continuous-time case and generalize the standard ones. Illustrative examples are given to verify the effectiveness of the developed results.
      PubDate: 2017-08-24T09:42:57.381901-05:
      DOI: 10.1002/asjc.1606
  • Boundary Stabilization of a Cosserat Elastic Body
    • Authors: Ali Najafi; Aria Alasty, Ramin Vatankhah, Mohammad Eghtesad, Farhang Daneshmand
      Pages: 2219 - 2225
      Abstract: Boundary stabilization of vibrating three-dimensional Cosserat elastic solids are studied using mathematical tools, such as operator theory and semigroup techniques. The advantages of the boundary control laws for both boundary stabilization problems are investigated. The boundary stabilization problems are studied using a Lyapunov stability method and LaSalle's invariant set theorem. Numerical simulations are provided to illustrate the effectiveness and performance of the designed control scheme.
      PubDate: 2017-08-16T06:51:55.47469-05:0
      DOI: 10.1002/asjc.1572
  • Observer Design for a Time Delay System via the Razumikhin Approach
    • Authors: Branislav Rehák
      Pages: 2226 - 2231
      Abstract: The paper presents an algorithm for the observer design for linear systems with time delay. The observer design is based on a solution of a set of linear matrix inequalities. They are derived using the Razumikhin functional. Quantization effects on the observation error are also studied, a bound on the observation error caused by quantization is derived. Two illustrative examples are presented.
      PubDate: 2017-05-16T01:55:58.725956-05:
      DOI: 10.1002/asjc.1507
  • Improved Adaptive H∞ Controller Synthesis of Piecewise-Affine
    • Authors: Hongwen Zhang; Kai Liu, Shangmin Zhang, Hong Qiao, Bobo Qiu
      Pages: 2232 - 2239
      Abstract: This paper considers the adaptive H∞ control problem for piecewise affine systems (PWS), a novel synthesis framework is presented based on the piecewise quadratic Lyapunov function (PQLF) instead of the common quadratic Lyapunov function to achieve the less conservatism. First, by designing the projection-type piecewise adaptive law, the problem of the adaptive H∞ control of PWS can be reduced to the H∞ control problem of augmented piecewise systems. Then, we construct the piecewise affine control law for augmented piecewise systems in such a way that the PQLF can be employed to establish the stability and H∞ performance. In particular, the Reciprocal Projection Lemma is employed to formulate the synthesis condition as linear matrix inequalities (LMIs), which enables the proposed PQLF approach to be numerically solvable. Finally, an engineering example is shown to illustrate the synthesis results.
      PubDate: 2017-05-12T06:41:22.549341-05:
      DOI: 10.1002/asjc.1523
  • Three-Dimensional Impact Angle Constrained Guidance Laws with Fixed-Time
    • Authors: Jiwei Gao; Yuan-Li Cai
      Pages: 2240 - 2254
      Abstract: In this paper, three dimensional coupled engagement dynamics are firstly transformed into a state-space form without decoupling three dimensional engagement dynamics into two mutually orthogonal planes to avoid degrading the performance of the guidance law. Specially, fixed-time guidance laws are proposed to guarantee that the line-of-sight (LOS) angular rates can be steered to zero before the final time of the guidance process at the same time. The exact convergence time can be set beforehand with respect to the LOS rates, and it is independent of initial conditions with respect to the guidance system. Moreover, impact angle constraint is taken into account, and these guidance laws are robust against maneuvering targets by sliding mode techniques. Simulation results validate the effectiveness of the proposed algorithms.
      PubDate: 2017-06-09T05:28:59.024556-05:
      DOI: 10.1002/asjc.1571
  • Special Issue on “Control Applications in Renewable Energy
    • Pages: 2270 - 2271
      PubDate: 2017-11-13T23:58:59.717044-05:
      DOI: 10.1002/asjc.1708
  • Special Issue on “SMC Based Observation, Identification, Uncertainties
           Compensation and Fault Detection”
    • Pages: 2272 - 2273
      PubDate: 2017-11-13T23:58:53.53678-05:0
      DOI: 10.1002/asjc.1709
  • Issue Information
    • Pages: 2274 - 2274
      Abstract: No abstract is available for this article.
      PubDate: 2017-11-13T23:58:57.164351-05:
      DOI: 10.1002/asjc.1408
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