for Journals by Title or ISSN for Articles by Keywords help
 Subjects -> COMPUTER SCIENCE (Total: 1991 journals)     - ANIMATION AND SIMULATION (27 journals)    - ARTIFICIAL INTELLIGENCE (76 journals)    - AUTOMATION (40 journals)    - COMPUTER ARCHITECTURE (9 journals)    - COMPUTER ASSISTED INSTRUCTION (25 journals)    - COMPUTER ENGINEERING (11 journals)    - COMPUTER GAMES (16 journals)    - COMPUTER GRAPHICS (32 journals)    - COMPUTER PROGRAMMING (19 journals)    - COMPUTER SCIENCE (1232 journals)    - COMPUTER SECURITY (44 journals)    - CYBERNETICS AND ROBOTICS (62 journals)    - DATA BASE MANAGEMENT (15 journals)    - DATA COMMUNICATIONS AND NETWORKS (75 journals)    - DATA MINING (23 journals)    - ELECTRONIC DATA PROCESSING (17 journals)    - INFORMATION SYSTEMS (93 journals)    - INTERNET (91 journals)    - SOCIAL WEB (46 journals)    - SOFTWARE (32 journals)    - THEORY OF COMPUTING (6 journals) COMPUTER SCIENCE (1232 journals)                  1 2 3 4 5 6 7 | Last
 Assembly Automation   [SJR: 0.439]   [H-I: 20]   [1 followers]  Follow         Hybrid journal (It can contain Open Access articles)    ISSN (Print) 0144-5154    Published by Emerald  [312 journals]
• Guest Editorial
• Authors: Bo Shen
First page: 109
Abstract: Assembly Automation, Volume 36, Issue 2, April 2016.

Citation: Assembly Automation
PubDate: 2016-02-24T10:04:13Z
DOI: 10.1108/AA-02-2016-014

• Takagi-Sugeno System for supervisory formation control of seeker mounted
unmanned aerial vehicles
First page: 111
Abstract: Assembly Automation, Volume 36, Issue 2, April 2016.
Purpose The main purpose of this paper is achieving a leader-follower formation of UAVs which is a cooperative scenario inspired by formation flying of living organisms such as geese. Designing a control strategy based on only vision measurement (without radio communication), and keeping connectivity in vision are important challenges in the formation flying problem which is the base of formation flying in living organisms. Design/methodology/approach To achieve the mentioned purposes, a feedback linearization technique is employed. Moreover, a Takagi-Sugeno based supervisory control strategy for visibility maintenance combined with an acceleration estimator in order to compensate the leader maneuvers is proposed. Findings We conclude that by employing practical seeker sensors, all the mentioned objectives (under the proposed strategy) can be satisfied. Originality/value Keeping formation and visibility maintenance in the presence of the leader maneuver are the main contributions of the paper.
Citation: Assembly Automation
PubDate: 2016-02-24T10:03:31Z
DOI: 10.1108/AA-09-2015-074

• Path planning for intelligent robot based on switching local evolutionary
PSO algorithm
• Authors: Nianyin Zeng, Hong Zhang, Yanping Chen, Binqiang Chen, Yurong Liu
First page: 120
Abstract: Assembly Automation, Volume 36, Issue 2, April 2016.
Purpose This paper presents a novel particle swarm optimization (PSO) based on a non-homogeneous Markov chain and differential evolution (DE) for path planning of intelligent robot when having obstacles in the environment. Design/methodology/approach The three-dimensional path surface of the intelligent robot is decomposed into a two-dimensional plane and the height information in z axis. Then, the grid method is exploited for the environment modeling problem. After that, a recently proposed switching local evolutionary PSO (SLEPSO) based on non-homogeneous Markov chain and differential evolution is analyzed for the path planning problem. The velocity updating equation of the presented SLEPSO algorithm jumps from one mode to another based on the non-homogeneous Markov chain, which can overcome the contradiction between local and global search. In addition, DE mutation and crossover operations can enhance the capability of finding a better global best particle in the PSO method. Findings Finally, the SLEPSO algorithm is successfully applied to the path planning in two different environments. Comparing with some well-known PSO algorithms, the experiment results show the feasibility and effectiveness of the presented method. Originality/value Therefore, this can provide a new method for the area of path planning of intelligent robot.
Citation: Assembly Automation
PubDate: 2016-02-24T10:03:52Z
DOI: 10.1108/AA-10-2015-079

• An advanced immune based strategy to obtain an optimal feasible assembly
sequence
• Authors: M V A Raju Bahubalendruni, Deepak B B V L, Bibhuti Bhusan Biswal
First page: 127
Abstract: Assembly Automation, Volume 36, Issue 2, April 2016.
Purpose A suitable assembly sequence consequences low cost manufacturing process with in minimal lead time. Optimal feasible Assembly sequence generation subjected to several assembly predicates influences search space of the problem and thereby computational time. The purpose of this investigation is to develop an intelligent methodology to find out an optimal feasible assembly sequence while considering the assembly predicates. Design/methodology/approach The proposed research work is carried by using two artificial immune system based models namely Bone Marrow Model and Negative Selection Algorithms in order to achieve the below objectives. • To obtain the possible number of assembly sequences. • To obtain the feasible assembly sequences while considering different assembly predicates. • To obtain an optimal feasible assembly sequence. Findings Proposed bone-marrow model determines the possible assembly sequences to ease the intricacy of the problem formulation. Further evaluation has been carried out through negative-selection censoring & monitoring models. These developed models reduce the overall computational time in order to determine the optimal feasible assembly sequence. Originality/value In this paper, the novel and efficient strategies based on artificial immune system have been developed and proposed to obtain all valid assembly sequences and optimized assembly sequence for a given assembled product using assembly attributes. The introduced methodology is proven its effectiveness in achieving optimal assembly sequence with less computational time.
Citation: Assembly Automation
PubDate: 2016-02-24T10:03:37Z
DOI: 10.1108/AA-10-2015-086

• A new genetic algorithm approach to smooth path planning for mobile robots
• Authors: Baoye Song, Zidong Wang, Li Sheng
First page: 138
Abstract: Assembly Automation, Volume 36, Issue 2, April 2016.
Purpose In this paper, the smooth path planning problem is considered for a mobile robot based on the genetic algorithm and the Bezier curve. Design/methodology/approach The workspace of a mobile robot is described by a new grid-based representation that facilitates the operations of the adopted genetic algorithm. The chromosome of the genetic algorithm is composed of a sequence of binary numbered grids (i.e., control points of the Bezier curve). Ordinary genetic operators including crossover and mutation are used to search the optimum chromosome where the optimization criterion is the length of a piecewise collision-free Bezier curve path determined by the control points. Findings This paper has proposed a new smooth path planning for a mobile robot by resorting to the genetic algorithm and the Bezier curve. A new grid-based representation of the workspace has been presented, which makes it convenient to perform operations in the genetic algorithm. The genetic algorithm has been used to search the optimum control points that determine the Bezier curve based smooth path. The effectiveness of the proposed approach has been verified by a numerical experiment, and some performances of the obtained method have also been analyzed. Research limitations/implications There still remain many interesting topics, for example, how to solve the specific smooth path planning problem by using the genetic algorithm? how to promote the computational efficiency in the more grids case? These issues deserve further research. Originality/value The purpose of this paper is to improve the existing results by making the following three distinctive contributions: 1) a rigorous mathematical formulation of the path planning optimization problem is formulated; 2) a general grid-based representation ($2^{n} \times 2^{n}$ grids) is proposed to describe the workspace of the mobile robots in order to facilitate the implementation of the GA where $n$ is chosen according to the trade-off between the accuracy and the computational burden; and 3) the control points of the Bezier curve are directly linked to the optimization criteria so that the generated paths are guaranteed to be optimal without any need for smoothing afterwards.
Citation: Assembly Automation
PubDate: 2016-02-24T10:03:48Z
DOI: 10.1108/AA-11-2015-094

• On the small fiber-coupled laser controller for animal robot
• Authors: Haixia Wang, Yuliang Wang, Yaozong Sun, Qiong Pu, Xiao Lu
First page: 146
Abstract: Assembly Automation, Volume 36, Issue 2, April 2016.
Purpose Because of the inconvenience and inflexibility of the laser controller, the applied range of the Optogenetics is limited. A portable remote-controlled laser controller system including the remote-controlled system and the laser stimulator is designed in the paper. Design/methodology/approach The remote-controlled system is handheld, which can wirelessly adjust the power and the emitting frequency of the laser by utilizing the ZigBee module. Findings The laser stimulator can be mounted on the animal due to only small weight of 35g and small volume of 40*40*20mm, which accomplishes validly the adjustable power and frequency by changing the current amplitude and duty radio. In the end, the experiments verify the reliability and effectiveness of the laser controller. Originality/value In virtue of the modular design of the driven circuit and the reasonable layout, the whole system has the advantages of small volume, convenient control and high stability, which provide the convenience for the development of portable optogenetics animal robot experiment and has broad market prospects.
Citation: Assembly Automation
PubDate: 2016-02-24T10:03:51Z
DOI: 10.1108/AA-11-2015-097

• Bio-inspired approach to invariant recognition and classification of
fabric weave patterns and yarn color
• Authors: Babar Khan, Fang Han, Zhijie Wang, Rana J Masood
First page: 152
Abstract: Assembly Automation, Volume 36, Issue 2, April 2016.
Purpose We proposed a biologically inspired processing architecture to recognize and classify fabrics with respect to the weave pattern (fabric texture) and yarn color (fabric color) Design/methodology/approach By using the fabric weave patterns image identification system, this study analyzed the fabric image based on the HMAX model of computer vision, to extract feature valuesrelated to texture of fabric. RGB color descriptor based on opponent color channels simulating the single opponent and double opponent neuronal function of the brain is incorporated in to the texture descriptor to extract yarn color feature values. Finally, Support Vector Machine (SVM) Classifier is used to train and test the algorithm. Findings This two-stage processing architecture can be used to construct a system based on computer vision to recognize fabric texture, and to increase the system reliability and accuracy. Using this method, the stability and fault-tolerance (invariance) was improved. Originality/value Traditionally, fabric texture recognition is performed manually by visual inspection. Recent studies have proposed automatic fabric texture identification based on computer vision. In the identification process, the fabric weave patterns are recognized by the warp and weft floats. However, due to the optical environments and the appearance differences of fabric and yarn, the stability and fault-tolerance (invariance) of the computer vision method are yet to be improved. By using our method, the stability and fault-tolerance (invariance) was improved.
Citation: Assembly Automation
PubDate: 2016-02-24T10:04:04Z
DOI: 10.1108/AA-11-2015-100

• A bio-inspired scan matching algorithm for mobile robots in outdoor
environments
• Authors: Fei Yan, Ke Wang, Jizhong Xiao, Ruifeng Li
First page: 159
Abstract: Assembly Automation, Volume 36, Issue 2, April 2016.
Purpose The most prominent example of scan matching algorithm is the Iterative Closest Point (ICP) algorithm. But the ICP algorithm and its variants excessively depend on the initial pose estimate between two scans. The paper proposes a scan matching algorithm, which is adaptable to big initial pose errors. Design/methodology/approach The environments are represented by flat units and upright units. The upright units are clustered to represent objects that the robot cannot cross over. The object cluster is further discretized to generate layered model consisting of cross-section ellipses. The layered model provides simplified features that facilitate an object recognition algorithm to discriminate among common objects in outdoor environments. A layered model graph is constructed with the recognized objects as nodes. Based on the similarity of sub-graphs in each scans, the layered model graph-based matching algorithm generates initial pose estimates and use ICP to refine the scan matching results. Findings Experimental results indicate that the proposed algorithm can deal with bad initial pose estimates and increase the processing speed. Its computation time is short enough for real-time implementation in robotic applications in outdoor environments. Originality/value This paper proposes a bio-Inspired scan matching algorithm for mobile robots based on layered model graph in outdoor environments.
Citation: Assembly Automation
PubDate: 2016-02-24T10:04:14Z
DOI: 10.1108/AA-11-2015-103

• Bio-inspired neural network with application to license plate recognition:
hysteretic ELM approach
• Authors: Liang Chen, Leitao Cui, Rong Huang, Zhengyun Ren
First page: 172
Abstract: Assembly Automation, Volume 36, Issue 2, April 2016.
Purpose The paper presents a bio-inspired neural network for improvement of information processing capability of the existing artificial neural networks. Design/methodology/approach In the network, we introduce a property often found in biological neural system – hysteresis – as the neuron activation function; and a bionic algorithm – extreme learning machine (ELM) – as the learning scheme. We give the gradient descent procedure to optimize parameters of the hysteretic function and develop an algorithm to online select ELM parameters, including number of the hidden-layer nodes and hidden-layer parameters. The algorithm combines the idea of the cross validation and random assignment in original ELM. Finally, we demonstrate the advantages of the hysteretic ELM neural network by applying it to automatic license plate recognition. Findings Experiments on automatic license plate recognition show that the bio-inspired learning system has better classification accuracy and generalization capability with consideration to efficiency. Originality/value Comparing with the conventional sigmoid function, hysteresis as the activation function enables has two advantages: 1) the neuron’s output not only depends on its input, but also on derivative information, that provides the neuron with memory; 2) the hysteretic function can switch between the two segments, thus avoiding the neuron falling into local minima and having a quicker learning rate. The improved ELM algorithm in some extent makes up for declining performance because of original ELM’s complete randomness with the cost of a litter slower than before.
Citation: Assembly Automation
PubDate: 2016-02-24T10:04:18Z
DOI: 10.1108/AA-11-2015-105

• Neural-network-based containment control of nonlinear multi-agent systems
under communication constraints
• Authors: Chao Ma
First page: 179
Abstract: Assembly Automation, Volume 36, Issue 2, April 2016.
Purpose The purpose of this paper is to investigate the neural-network-based containment control of multi-agent systems with unknown nonlinear dynamics. Moreover, communication constraints are taken into account to reflect more realistic communication network. Design/methodology/approach Based on the approximation property of the radial basis function neural networks, the control protocol for each agent is designed, where all the information is exchanged in the form of sampled data instead of ideal continuous-time communications. Findings By utilizing Lyapunov stability theory and Lyapunov-Krasovskii functional approach, sufficient conditions are developed to guarantee that all the followers can converge to the convex hull spanned by the stationary leaders. Originality/value Since ideal continuous-time communications of the multi-agent systems are very difficult or even unavailable to achieve, the neural-network-based containment control of nonlinear multi-agent systems is solved under communication constraints. More precisely, sampled-data information is exchanged, which is more applicable and practical in the real world applications.
Citation: Assembly Automation
PubDate: 2016-02-24T10:04:21Z
DOI: 10.1108/AA-11-2015-107

• A novel path planning method for biomimetic robot based on deep learning
• Authors: Yang Lu, Shujuan Yi, Yurong Liu, Yuling Ji
First page: 186
Abstract: Assembly Automation, Volume 36, Issue 2, April 2016.
Purpose We designed a multi-layer convolutional neural network to solve biomimetic robot path planning problem. Design/methodology/approach At first, the convolution kernel with different scales can be got by using the sparse auto encoder training algorithm, the parameter of the hidden layer is a series of convolutional kernel, and we use these kernels to extract first-layer features. Then we get the second-layer features through the max-pooling operators, which improves the invariance of the features. At last, we use fully connected layers of neural networks to accomplish the path planning task. Findings The NAO biomimetic robot respond quickly and correctly to the dynamic environment. The simulation experiments show that the deep neural network outperforms in dynamic and static environment than the conventional method. Originality/value A new method of deep learning based biomimetic robot path planning is proposed. We designed a multi-layer convolutional neural network which includes max-pooling layer and convolutional kernel. Then the first and second layers features can be extracted by these kernels. Finally, we use the sparse auto encoder training algorithm to train the convolutional neural network so as to accomplish the path planning task of NAO robot.
Citation: Assembly Automation
PubDate: 2016-02-24T10:04:21Z
DOI: 10.1108/AA-11-2015-108

• Improved GA and pareto optimization-based facial expression recognition
• Authors: Fowei Wang, Bo Shen, Shaoyuan Sun, Zidong Wang
First page: 192
Abstract: Assembly Automation, Volume 36, Issue 2, April 2016.
Purpose The purpose of this paper is to improve the accuracy of the facial expression recognition by using genetic algorithm (GA) with an appropriate fitness evaluation function and Pareto optimization model with two new objective functions Design/methodology/approach In order to achieve facial expression recognition with high accuracy, the Haar-like features representation approach and the Bilateral filter are firstly used to preprocess the facial image. Secondly, the uniform LGBP is employed to extract the facial feature so as to reduce the feature dimension. Thirdly, an improved GA and Pareto optimization approach are employed to select the optimal significant features. Fourthly, the random forest classifier is chosen to achieve the feature classification. Subsequently, some comparative experiments are implemented. Finally, the conclusion is drawn and some future research topics are pointed out. Findings The experiment results show that the proposed facial expression recognition algorithm outperforms ones in the existing literature in terms of both the actuary and computational time. Originality/value The GA and Pareto optimization algorithm are combined to select the optimal significant feature. In order to improve the accuracy of the facial expression recognition, the GA is improved by adjusting an appropriate fitness evaluation function and a new Pareto optimization model is proposed that contains two objective functions indicating the achievements in minimizing within-class variations and in maximizing between-class variations.
Citation: Assembly Automation
PubDate: 2016-02-24T10:04:28Z
DOI: 10.1108/AA-11-2015-110

• Bio-inspired kinematical control of redundant robotic manipulators
• Authors: Ali Leylavi Shoushtari, Stefano Mazzoleni, Paolo Dario
First page: 200
Abstract: Assembly Automation, Volume 36, Issue 2, April 2016.
Purpose In this paper an innovative kinematic control algorithm is proposed for redundant robotic manipulators. The algorithm takes advantage of a bio-inspired approach. Design/methodology/approach A simplified 2 DOFs model is presented to handle kinematic redundancy in the x-y plane; an extension to three-dimensional tracking tasks is presented as well. A set of sample trajectories were used to evaluate the performances of the proposed algorithm. Findings The results from the simulations confirm the continuity and accuracy of generated joint profiles for given end-effector trajectories as well as algorithm robustness, singularity and self-collision avoidance. Originality/value This paper shows how to control a redundant robotic arm by applying human upper arm-inspired concept of inter-joint dependency.
Citation: Assembly Automation
PubDate: 2016-02-24T10:03:30Z
DOI: 10.1108/AA-11-2015-116

• An interactive Virtual Lighting Maintenance Environment for Human Factors
Evaluation
• Authors: Qichang He, Shiguang Qiu, Xiumin Fan, Keyan Liu
First page: 1
Abstract: Assembly Automation, Volume 36, Issue 1, February 2016.
Purpose The paper aims to establish a VLME (Virtual Lighting Maintenance Environment), and to analyze the visibility related HFs (Human Factors) during maintenance operations through interactive simulations. Design/methodology/approach Firstly, an accurate task lighting modeling method was developed, which includes lighting information modeling and illuminant parameters calibration. Then, the real-time interaction between the task lighting and 3D virtual human was modeled. After that, the attenuation coefficient of visibility was determined. Also, the HFs analysis process in VLME was described in detail. Findings A case study of PSM (Power Supply Module) replacement of radar equipment was performed in VLME. The HFs analysis demonstrated that the task lighting significantly affects the visibility, which causes indirect impact on posture comfort and operation safety. Practical implications Through evaluating maintenance operation processing in lighting environment, engineers can better analyze and validate the maintainability design for complex equipment, and some potential ergonomics and safety issues can be found and dealt earlier. Originality/value A VLME was built for interactive “human-in-loop” maintenance operation simulation, which can support HFs evaluation in lighting environment accurately and effectively.
Citation: Assembly Automation
PubDate: 2015-12-18T12:43:06Z
DOI: 10.1108/AA-04-2015-029

• Design for assembly and disassembly for remanufacturing
• Authors: SL Soh, S K Ong, A Y C Nee
First page: 12
Abstract: Assembly Automation, Volume 36, Issue 1, February 2016.
Purpose This research proposes a methodology for a systematic, concurrent consideration of design for assembly and disassembly guidelines and constraints for product remanufacturing. The methodology provides a holistic approach to product design from the remanufacturing perspective. Design/methodology/approach The proposed methodology incorporates parts integration assessment, and evaluation of part complexity and accessibility taking into consideration both DFA and DFD design guidelines and constraints. Metrics for accessibility and complexity in retrieving the remanufacturable cores from a product are evaluated to determine the best possible disassembly route considering the practical constraints which an operator might face during disassembly. As there could be more than one feasible disassembly route to retrieve a core during remanufacturing, a disassembly evaluation is conducted to determine the optimal path after parts combination of the assembly. Findings In remanufacturing, products need to be disassembled and re-assembled again. Conflicts exist between design for assembly and disassembly. The proposed methodology serves to address these conflicting issues. The proposed methodology eases a designer’s effort systematically to incorporate both aspects, by incorporating practical consideration to determine an optimal disassembly sequence through integrating the handling aspect of assembly complexity assessment with the U-Rating disassembly effort indexing scheme to provide a quantitative evaluation of disassembly complexity since disassembly still largely requires human effort. Research limitations/implications Further research can be looked into how the methodology proposed can be realized through implementation of a Design for Assembly and Disassembly software interface, to allow designers to input require data as well as extract relevant product information automatically from the CAD environment. Originality/value This paper proposed a methodology for a systematic, concurrent consideration of design for assembly and disassembly to provide a holistic approach to product design from the remanufacturing perspective to ease the designer’s task. Practical considerations will be made to determine the optimal disassembly route of the product. Design for disassembly will only be required to be applied to the selected disassembly route to minimize conflicts with design for assembly.
Citation: Assembly Automation
PubDate: 2015-12-18T12:42:34Z
DOI: 10.1108/AA-05-2015-040

• Error sensitivity analysis of a microassembly system with coaxial
alignment function
• Authors: Xin Ye, Pan Liu, Zhijing Zhang, Chao Shao, Yan Li
First page: 25
Abstract: Assembly Automation, Volume 36, Issue 1, February 2016.
Purpose This paper is to analyze the sensitivity of the motion error parameters in microassembly process, thereby improving the assembly accuracy. For the motion errors of the precision motion stages directly affect the final assembly quality after the machine visual alignment. Design/methodology/approach This paper presents the error parameters of the in-house microassembly system with coaxial alignment function; builds the error transfer model by the multi-body system theory; analyzes the error sensitivity on the sensitive direction using the Sobol method which was based on variance; and then gets the ones which made a great degree of influence. Before the sensitivity analyzing, parts of the error sources have been measured to obtain their distribution ranges. Findings The results of the sensitivity analysis by the Sobol method which was based on variance are coincident with the theoretical analysis. Besides, the results provide a reference for the error compensation in control process; for the selection of the precision motion stages; and for the installation index of the motion stages of the assembly system with coaxial alignment. Originality/value This kind of error sensitivity analysis method is of great significance for improving the assembly accuracy after visual system positioning, and increasing efficiency from the initial motion stage selection to final error compensation for designers. It is suitable for general precision motion systems be of multi degree of freedom, for the method of modeling, measuring and analyzing used in this paper are all universal and applicative.
Citation: Assembly Automation
PubDate: 2015-12-18T12:42:37Z
DOI: 10.1108/AA-02-2015-010

• A novel assembly simulation method based on semantics and geometric
constraint
• Authors: Pan Wang, Yuan Li, Lin Yu, Jie Zhang, Zhijia Xu
First page: 34
Abstract: Assembly Automation, Volume 36, Issue 1, February 2016.
Purpose Currently, assembly simulation is always carried out by human-computer interaction, which is a time-consuming and tedious work. The most responsible reason for this problem is that the assembly simulation is a mapping between human intent and movements of models, at the same time, assembly information is transferred from semantic level to geometric level. However, some essential assembly information lost during the transfer, and it must be accomplished through manual definition. To address the issue, a novel assembly simulation method is proposed in this paper based on semantics and geometric constraint. Design/methodology/approach Firstly, an assembly operation semantic model is put forward to integrate and manage the semantic information of assembly, and some rules for modeling are generalized. Secondly, method for transferring assembly information from semantic level to geometric level is presented by dividing assembly operation into a set of simulation actions and providing some rules of the dividing. Then, a geometric constraint based calculation method is proposed to obtain the essential parameters of each simulation action. Finally, cases are studied to demonstrate the effectiveness of the method. Findings The results show that the laborious work would be reduced and the redundant human participation would be avoided in assembly simulation. Practical implications It has the potential and possibility to change the current pattern of assembly simulation. Originality/value A novel assembly simulation method based on semantics and geometric constraint is presented to make assembly simulation more convenient and faster.
Citation: Assembly Automation
PubDate: 2015-12-18T12:42:52Z
DOI: 10.1108/AA-05-2015-036

• A multi-manned assembly line balancing problem with classified teams: A
new approach
• Authors: Hamid Yilmaz, Mustafa Yilmaz
First page: 51
Abstract: Assembly Automation, Volume 36, Issue 1, February 2016.
Purpose This paper draws attention to assembly line balancing problem in which workers have been assigned to teams in advance due to the need for specialized skills or equipment on the line for the first time. Within team-oriented approaches, tasks are assigned to teams before being assigned to workstations as a reality of industry. So it becomes clear that, which workers assemble which tasks. Design/methodology/approach Team numbers of the assembly line can increase with the number of tasks, but at same time, due to physical situations of the stations, there will be limitations of maximum working team numbers in a station. For this purpose heuristic assembly line balancing procedure is used and mathematical model is developed for the problem. Findings Well-known assembly line test problems widely used in the literature are solved to indicate the effectiveness and applicability of the proposed approach in practice. Originality/value This paper draws attention to assembly line balancing problem in which workers have been assigned to teams in advance due to the need for specialized skills or equipment on the line for the first time.
Citation: Assembly Automation
PubDate: 2015-12-18T12:42:50Z
DOI: 10.1108/AA-04-2015-035

• An efficient evolutionary method of assembly sequence planning for
shipbuilding industry
• First page: 60
Abstract: Assembly Automation, Volume 36, Issue 1, February 2016.
Purpose The main aim of this article is to develop the method of generating assembly sequences, which can be used in the shipbuilding industry. The method must take into account the assumptions specific for assembly processes of large-size steel ship hulls, among others, a large number of connections, multi-stage and parallel assembly, set priority relations between connections. Design/methodology/approach The assembly sequence is presented as a directed acyclic graph, which vertices are mutually uniquely assigned to connections on a hull structure. The minimization of the number of unmet priority precedence of performing connections has been proposed as a criterion of optimization. The genetic algorithm has been proposed as a method to solve problems. Findings The proposed method allows to model the acyclic assembly process of welded structures and find solutions minimizing the objective function even for very complex problems. Because of this, the method has a chance to be used in shipbuilding. Research limitations/implications Mathematical formulation of priority assumptions is quite laborious. The possibility of partial automation of this process should be considered. Due to the complexity of the problem a relatively simplified objective function has been proposed. In assembling a hull additional criteria should be taken into account. It is the direction of further research. Practical implications The method can be successfully used in shipbuilding and in planning the production of other steel welded structures, among others, tanks, components of bridges, offshore structures. Examples of calculations were performed on an actual structure of a hull fragment. Originality/value A new way of coding the acyclic serial-parallel sequence was designed. The proposed method allows to analyse the sequence using the graph theory. Original, two-part crossover and mutation operators for assembling sequence were proposed.
Citation: Assembly Automation
PubDate: 2015-12-18T12:42:29Z
DOI: 10.1108/AA-02-2015-013

• Geometric tolerance analysis through Jacobian model for rigid assemblies
with translational deviations
• Authors: Wilma Polini, Andrea Corrado
First page: 72
Abstract: Assembly Automation, Volume 36, Issue 1, February 2016.
Purpose Tolerance analysis is an important task to design and to manufacture high precision mechanical assemblies; it has received considerable attention by the literature. The Jacobian model is one of the methods proposed by the literature for tolerance analysis. The Jacobian model cannot deal with geometric tolerances for mechanical assemblies. The geometric tolerances may not be neglected for assemblies, since they significantly influence their functional requirements. Design/methodology/approach This work presents how it is possible to deal with geometric tolerances when a tolerance analysis is carried out by means of a Jacobian model for a 2D and 3D assemblies for which the geometric tolerances applied to the components involves only translational deviations. The three proposed approaches modify the expression of the stack-up function in order to overcome the shortage of Jacobian model that the geometric error cannot be processed. Findings The proposed approach has been applied to a case study. The results of the case study show how, when a statistical approach is implemented, the Jacobian model with the three developed methods give results very similar to those due to other models of the literature, such as vector loop and variational. Research limitations/implications In particular, the proposed approach may be applied only when the applied geometrical tolerances involve translational variations in 3D assemblies. Practical implications Tolerance analysis is a valid tool to foresee geometric interferences among the components of an assembly before getting the physical assembly. It involves a decrease of the manufacturing costs. Originality/value The original contribution of the paper is due to three methods to make a Jacobian model able to consider form and geometric deviations.
Citation: Assembly Automation
PubDate: 2015-12-18T12:43:04Z
DOI: 10.1108/AA-11-2015-088

• Determination of the base position and working area for mobile
manipulators
• Authors: Shunan Ren, Xiangdong Yang, Jing Xu, Guolei Wang, Ying Xie, Ken Chen
First page: 80
Abstract: Assembly Automation, Volume 36, Issue 1, February 2016.
Purpose The purpose of this article is to determine the base position and the largest working area for mobile manipulators. The base position determines the workspace of the mobile manipulator, particularly when the operation mode is intermittent (i.e., the mobile platform stops when the manipulator conducts the task). When the base of the manipulator is in the intersection area of the Base’s Workable Location Spaces (BWLSes), the end effector (EE) can reach all path points. In this study, the intersection line of BWLSes is calculated numerically, and the largest working area is determined using the BWLS concept. The performance of this method is validated with simulations on specific surface segments, such as plane, cylinder, and conical surface segments. Design/methodology/approach The BWLS is used to determine the largest working area and the base position in which the mobile manipulator can reach all path points with the objective of reducing off-line planning time. Findings Without considering the orientation of the EE, the base position and the working area for the mobile manipulator are determined using the BWLS. Compared to other methods, the proposed algorithm is beneficial when the planning problem has six dimensions, ensuring the reachability and stability of the EE. Originality/value The algorithm needs no manual configuration, and its performance is investigated for typical surfaces in practical applications.
Citation: Assembly Automation
PubDate: 2015-12-18T12:42:48Z
DOI: 10.1108/AA-11-2015-101

• Synchronization of discrete-time multi-agent systems under input sets with
limited precision
• Authors: Yang Meng, Zi Wang
First page: 89
Abstract: Assembly Automation, Volume 36, Issue 1, February 2016.
Purpose The paper mainly aims to study that for multi-agent systems, how to find proper control protocols to ensure synchronization when the input set of each agent is not the whole real axis but a discrete set, and how the coarseness of imprecise input sets affect the synchronization control of the multi-agent systems. Design/methodology/approach The paper uses a relative state feedback method and nonlinear mapping functions to design a proper control protocol which matches the coarseness of the input set and ensures synchronization. For theoretical analysis, the paper uses an error analysis method and mathematic induction to prove the effectiveness of the designed control protocol. Findings The paper provides a method for protocol design when the input set of each agent is imprecise. The paper establish a bi-direction relationship which suffices for synchronization between the coarseness of the input set and the synchronization precision, and find that this relationship describes how the coarseness of the input set affects the synchronization control of the multi-agent system. Research limitations/implications The authors are encouraged to study the synchronization control of multi-agent systems under input sets with more general distributions. Practical implications The paper includes implications for coordination control of multi-agent networks when the actuator of each agent is with limit capacity, which leads to the case of discrete input sets with limit precision. Originality/value This paper fulfils an identified need to study how the coarseness of the input set of each agent affects the synchronization control of the whole multi-agent system.
Citation: Assembly Automation
PubDate: 2015-12-18T12:42:28Z
DOI: 10.1108/AA-12-2015-117

• Human-inspired motion model of upper-limb with fast response and learning
ability - A promising direction for robot system and control
• Authors: Hong Qiao, Chuan Li, Peijie Yin, Wei Wu, Zhi-Yong Liu
First page: 97
Abstract: Assembly Automation, Volume 36, Issue 1, February 2016.
Purpose Human movement system is a Multi-DOF, redundant, complex and nonlinear system formed by coordinating combination of neural system, bones, muscles and joints, which is robust and has fast response and learning ability. Imitating human movement system can improve robustness, fast response and learning ability of the robots. Design/methodology/approach In this paper, we propose a new motion model based on the human motion pathway, especially the information propagation mechanism between the cerebellum and spinal cord. Findings The proposed motion model proves to have fast response and learning ability through experiments, which matches the features of human motion. Originality/value The proposed model in this paper introduces the habitual theory in kinesiology and neuroscience into robot control, and improves robustness, fast response and learning ability of the robots. This paper proves that introduction of neuroscience has an important guiding significance for precise and adaptive robot control, such as assembly automation.
Citation: Assembly Automation
PubDate: 2015-12-18T12:42:47Z
DOI: 10.1108/AA-11-2015-099

JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327