Good understanding of relationship between parameters of vehicle, terrain and interaction at the interface is required to develop effective navigation and motion control algorithms for autonomous wheeled mobile robots...Good understanding of relationship between parameters of vehicle, terrain and interaction at the interface is required to develop effective navigation and motion control algorithms for autonomous wheeled mobile robots (AWMR) in rough terrain. A model and analysis of relationship among wheel slippage (S), rotation angle (0), sinkage (z) and wheel radius (r) are presented. It is found that wheel rotation angle, sinkage and radius have some influence on wheel slippage. A multi-objective optimization problem with slippage as utility function was formulated and solved in MATLAB. The results reveal the optimal values of wheel-terrain parameters required to achieve optimum slippage on dry sandy terrain. A method of slippage estimation for a five-wheeled mobile robot was presented through comparing the odometric measurements of the powered wheels with those of the fifth non-powered wheel. The experimental result shows that this method is feasible and can be used for online slippage estimation in a sandy terrain.展开更多
As a new sort of mobile ad hoc network(MANET), aeronautical ad hoc network(AANET) has fleet-moving airborne nodes(ANs) and suffers from frequent network partitioning due to the rapid-changing topology. In this work, t...As a new sort of mobile ad hoc network(MANET), aeronautical ad hoc network(AANET) has fleet-moving airborne nodes(ANs) and suffers from frequent network partitioning due to the rapid-changing topology. In this work, the additional relay nodes(RNs) is employed to repair the network and maintain connectivity in AANET. As ANs move, RNs need to move as well in order to re-establish the topology as quickly as possible. The network model and problem definition are firstly given, and then an online approach for RNs' movement control is presented to make ANs achieve certain connectivity requirement during run time. By defining the minimum cost feasible moving matrix(MCFM), a fast algorithm is proposed for RNs' movement control problem. Simulations demonstrate that the proposed algorithm outperforms other control approaches in the highly-dynamic environment and is of great potential to be applied in AANET.展开更多
To control movement,the brain has to integrate proprioceptive information from a variety of mechanoreceptors.The role of proprioception in daily activities,exercise,and sports has been extensively investigated,using d...To control movement,the brain has to integrate proprioceptive information from a variety of mechanoreceptors.The role of proprioception in daily activities,exercise,and sports has been extensively investigated,using different techniques,yet the proprioceptive mechanisms underlying human movement control are still unclear.In the current work we have reviewed understanding of proprioception and the three testing methods:threshold to detection of passive motion,joint position reproduction,and active movement extent discrimination,all of which have been used for assessing proprioception.The origin of the methods,the different testing apparatus,and the procedures and protocols used in each approach are compared and discussed.Recommendations are made for choosing an appropriate technique when assessing proprioceptive mechanisms in different contexts.展开更多
Movable cellular automata (MCA) method is applied in the analysis of dynamic characters of ceramic armor composite structures under impact loading. As a new approach, MCA is different from the traditional numerical me...Movable cellular automata (MCA) method is applied in the analysis of dynamic characters of ceramic armor composite structures under impact loading. As a new approach, MCA is different from the traditional numerical methods such as the finite element method and boundary element method. Based on the theory of particle mechanics, MCA is applied as a powerful tool in solving specific structural analysis of materials loss and penetrating damages. In this paper the method is used to study responses of multi-layered ceramic plates as a base of armor structures under impact loading, thus assisting further investigations in the crashing process and to improve ceramic armor structures.展开更多
Hybrid mecihanism is a new type of planar controllable mechanism. Position control acouracy of system determines the output aconracy of the mechanism. In order to achieve the desired high acowacy, nonlinear factors as...Hybrid mecihanism is a new type of planar controllable mechanism. Position control acouracy of system determines the output aconracy of the mechanism. In order to achieve the desired high acowacy, nonlinear factors as friction nmst be accurately compensated in the real-time servo control algoritinn. In this paper, the model of a hybrid five-bar mechanism is introduced. In terms of the characteristics of the hybrid mechanism, a hybrid intelligent control algorithm based on proportional-integral-derivative (PID) control and cerebellar model articulation control techniques was presented and used to perform control of hybrid five-bar mechanism for the lust time. The sinmulation results show that the hybrid control method can improve the control effect remarkably, compared with the traditional PID control strategy.展开更多
The goal of this paper is to improve human visual perceptual quality as well as coding efficiency of H. 264 video at low bit rate conditions by adaptively adjusting the number of skipped frames. The encoding frames ar...The goal of this paper is to improve human visual perceptual quality as well as coding efficiency of H. 264 video at low bit rate conditions by adaptively adjusting the number of skipped frames. The encoding frames are selected according to the motion activity of each frame and the motion accumulation of successive frames. The motion activity analysis is based on the statistics of motion vectors and with consider- ation of the characteristics of H. 264 coding standard. A prediction model of motion accumulation is pro- posed to reduce complex computation of motion estimation. The dynamic encoding frame rate control algorithm is applied to both the frame level and the GOB (Group of Macroblocks ) level. Simulation is done to compare the performance of JM76 with the proposed frame level scheme and GOB level scheme.展开更多
Behavior-based flocking has got remarkable attention in the recent past. The flocking algorithms can have inherent properties like organizing,healing and re-configuring for a distributed system. In this research we pr...Behavior-based flocking has got remarkable attention in the recent past. The flocking algorithms can have inherent properties like organizing,healing and re-configuring for a distributed system. In this research we presented the emergent flocking behavior-based control. We defined the basis behavior and with variety of combination, and obtained a complex group behavior flocking. Unlike classical flocking, we implemented additional rules obstacle avoidance,formation and seek target which results in V-formation flocking while avoiding obstacles. We performed the visual simulation of our flocking algorithm using MATLAB. The results concluded that the multi-boid flock could successfully navigate to the target while avoiding collisions. This can be applied to areas where we need to maximize the coverage of sensors or minimize the risk of combative attack,both in military and civilian scenarios.展开更多
Motion simulator usually appears the phenomenon of false cues and the workspace is limited in the process of washout. The proposed washout algorithm combines fuzzy logic control with the vestibular system to design th...Motion simulator usually appears the phenomenon of false cues and the workspace is limited in the process of washout. The proposed washout algorithm combines fuzzy logic control with the vestibular system to design the tilt coordination fuzzy adaptive filter, in order to minimize the vestibular sensory error below the human perception threshold. Owing to tilt coordination angular velocity limiter, the loss of low-pass acceleration must be compensated by the acceleration transform model. The translational channel decreases the possibility of the workspace beyond limitation and expands the scope of motion platform simulating input acceleration by using third-order filter. The simulation results show that the proposed algorithm can effectively overcome the phase retardation of classical washout algorithm, and then prevent the produce of false cues, decrease the displacement of motion platform simultaneously; in addition, white Gaussian noise simulates large variations in acceleration. The proposed washout algorithm can have maximal extreme value of acceleration and accurate simulating performance in general. It also proves that the proposed washout algorithm has a strong adaptability and reliability, which can effectively improve the dynamic fidelity for motion simulator.展开更多
In order to improve the modernization level of sports comprehensive evaluation, a comprehensive evaluation method of sports modernization based on analytic hierarchy process (AHP) is proposed. An index analysis mode...In order to improve the modernization level of sports comprehensive evaluation, a comprehensive evaluation method of sports modernization based on analytic hierarchy process (AHP) is proposed. An index analysis model for constructing the comprehensive evaluation of sports modernization is constructed, spatial modeling of information feature distribution is taken based on nonlinear time series analysis method for comprehensive evaluation of sports modernization, control objective function of comprehensive evaluation of sports modernization is constructed by analytic hierarchy process, optimal control parameters is obtained and comprehensive evaluation and optimization of sports modernization are realized. The simulation results show that the method is applied in comprehensive evaluation modem sports, it has performance of high reliability and good accuracy.展开更多
The article presents multi-pattern formation exchange of mobile robots according to the image signals, programs motion paths using A* searching algorithm, and avoids the collision points of motion paths. The system c...The article presents multi-pattern formation exchange of mobile robots according to the image signals, programs motion paths using A* searching algorithm, and avoids the collision points of motion paths. The system contains an image system, a grid based motion platform, some wireless Radio Frequency (RF) modules and five mobile robots. We use image recognition algorithm to classify variety pattern formation according to variety Quick Response (QR) code symbols on the user interface of the supervised computer. The supervised computer controls five mobile robots to execute formation exchange and presents the movement scenario on the grid based motion platform. We have been developed some pattern formations according to game applications, such as long snake pattern formation, phalanx pattern formation, crane wing pattern formation, sword pattern formation, cone pattern formation, sward pattern tbrmation, T pattern formation, rectangle pattern formation and so on. We develop the user interface of the multi-robot system to program motion paths for variety pattern formation exchange according to the minimum displacement. In the experimental results, the supervised computer recognizes the various QR-code symbols using image system and decides which pattern formation to be selected on real-time. Mobile robots can receive the pattern formation command from the supervised computer, present the movement scenario from the original pattern formation to the assigned pattern formation on the motion platform, and avoid other mobile robots on real-time.展开更多
Based on the structure of Elman and Jordan neural networks, a new dynamic neural network is constructed. The network can remember the past state of the hidden layer and adjust the effect of the past signal to the curr...Based on the structure of Elman and Jordan neural networks, a new dynamic neural network is constructed. The network can remember the past state of the hidden layer and adjust the effect of the past signal to the current value in real-time. And in order to enhance the signal processing capabilities, the feedback of output layer nodes is increased. A hybrid learning algorithm based on genetic algorithm (GA) and error back propagation algorithm (BP) is used to adjust the weight values of the network, which can accelerate the rate of convergence and avoid getting into local optimum. Finally, the improved neural network is utilized to identify underwater vehicle (UV) ' s hydrodynamic model, and the simulation results show that the neural network based on hybrid learning algorithm can improve the learning rate of convergence and identification nrecision.展开更多
This paper considers the formatiomshape control of three agents in the plane. By adding an adaptive perturbation to any agent's movement direction, a novel control strategy is proposed. It is shown that the proposed ...This paper considers the formatiomshape control of three agents in the plane. By adding an adaptive perturbation to any agent's movement direction, a novel control strategy is proposed. It is shown that the proposed novel control law can not only guarantee the global asymptotical stability of the desired formation shape, but also ensure the collision avoidance of agents between each other. Simulation results are provided to illustrate the effectiveness of the control algorithm.展开更多
Dynamic modeling and active control of a strap-on launch vehicle are studied in this paper. In the dynamic modeling, the double-compatible free-interface modal synthesis method is used to establish dynamic model of th...Dynamic modeling and active control of a strap-on launch vehicle are studied in this paper. In the dynamic modeling, the double-compatible free-interface modal synthesis method is used to establish dynamic model of the system, and its model precision is compared with those of finite element method(FEM), fixedinterface modal synthesis method and free-interface modal synthesis method. In the active control, the swing angle of rocket motor is used as design variable, and the control law design based on the model of mass center motion is adopted to validate the system. Simulation results indicate that the double-compatible model synthesis method can properly approximate the FEM which is used as the benchmark solution, and the model precision of the double-compatible modal synthesis method is obviously higher than those of the fixed-interface and freeinterface modal synthesis methods. Based on the control law design, the deflection of mass center of the launch vehicle is very small.展开更多
基金Project(60775060) supported by the National Natural Science Foundation of ChinaProject(F200801) supported by the Natural Science Foundation of Heilongjiang Province,China+1 种基金Project(200802171053,20102304110006) supported by the Specialized Research Fund for the Doctoral Program of Higher Education of ChinaProject(2012RFXXG059) supported by Harbin Science and Technology Innovation Talents Special Fund,China
文摘Good understanding of relationship between parameters of vehicle, terrain and interaction at the interface is required to develop effective navigation and motion control algorithms for autonomous wheeled mobile robots (AWMR) in rough terrain. A model and analysis of relationship among wheel slippage (S), rotation angle (0), sinkage (z) and wheel radius (r) are presented. It is found that wheel rotation angle, sinkage and radius have some influence on wheel slippage. A multi-objective optimization problem with slippage as utility function was formulated and solved in MATLAB. The results reveal the optimal values of wheel-terrain parameters required to achieve optimum slippage on dry sandy terrain. A method of slippage estimation for a five-wheeled mobile robot was presented through comparing the odometric measurements of the powered wheels with those of the fifth non-powered wheel. The experimental result shows that this method is feasible and can be used for online slippage estimation in a sandy terrain.
文摘As a new sort of mobile ad hoc network(MANET), aeronautical ad hoc network(AANET) has fleet-moving airborne nodes(ANs) and suffers from frequent network partitioning due to the rapid-changing topology. In this work, the additional relay nodes(RNs) is employed to repair the network and maintain connectivity in AANET. As ANs move, RNs need to move as well in order to re-establish the topology as quickly as possible. The network model and problem definition are firstly given, and then an online approach for RNs' movement control is presented to make ANs achieve certain connectivity requirement during run time. By defining the minimum cost feasible moving matrix(MCFM), a fast algorithm is proposed for RNs' movement control problem. Simulations demonstrate that the proposed algorithm outperforms other control approaches in the highly-dynamic environment and is of great potential to be applied in AANET.
基金the University of Canberra,Key Laboratory of Exercise and Health Sciences of Ministry of Education,Shanghai University of Sport and Shanghai Municipal Science and Technology Commission (No.13490503800)supported by Shanghai Pujiang Program (No.15PJ1407600)
文摘To control movement,the brain has to integrate proprioceptive information from a variety of mechanoreceptors.The role of proprioception in daily activities,exercise,and sports has been extensively investigated,using different techniques,yet the proprioceptive mechanisms underlying human movement control are still unclear.In the current work we have reviewed understanding of proprioception and the three testing methods:threshold to detection of passive motion,joint position reproduction,and active movement extent discrimination,all of which have been used for assessing proprioception.The origin of the methods,the different testing apparatus,and the procedures and protocols used in each approach are compared and discussed.Recommendations are made for choosing an appropriate technique when assessing proprioceptive mechanisms in different contexts.
文摘Movable cellular automata (MCA) method is applied in the analysis of dynamic characters of ceramic armor composite structures under impact loading. As a new approach, MCA is different from the traditional numerical methods such as the finite element method and boundary element method. Based on the theory of particle mechanics, MCA is applied as a powerful tool in solving specific structural analysis of materials loss and penetrating damages. In this paper the method is used to study responses of multi-layered ceramic plates as a base of armor structures under impact loading, thus assisting further investigations in the crashing process and to improve ceramic armor structures.
文摘Hybrid mecihanism is a new type of planar controllable mechanism. Position control acouracy of system determines the output aconracy of the mechanism. In order to achieve the desired high acowacy, nonlinear factors as friction nmst be accurately compensated in the real-time servo control algoritinn. In this paper, the model of a hybrid five-bar mechanism is introduced. In terms of the characteristics of the hybrid mechanism, a hybrid intelligent control algorithm based on proportional-integral-derivative (PID) control and cerebellar model articulation control techniques was presented and used to perform control of hybrid five-bar mechanism for the lust time. The sinmulation results show that the hybrid control method can improve the control effect remarkably, compared with the traditional PID control strategy.
基金Supported by the High Technology. Research and Development Program of China (No. 2005AA103310) and the National Natural Science Foundation of China (No. 60202006).
文摘The goal of this paper is to improve human visual perceptual quality as well as coding efficiency of H. 264 video at low bit rate conditions by adaptively adjusting the number of skipped frames. The encoding frames are selected according to the motion activity of each frame and the motion accumulation of successive frames. The motion activity analysis is based on the statistics of motion vectors and with consider- ation of the characteristics of H. 264 coding standard. A prediction model of motion accumulation is pro- posed to reduce complex computation of motion estimation. The dynamic encoding frame rate control algorithm is applied to both the frame level and the GOB (Group of Macroblocks ) level. Simulation is done to compare the performance of JM76 with the proposed frame level scheme and GOB level scheme.
文摘Behavior-based flocking has got remarkable attention in the recent past. The flocking algorithms can have inherent properties like organizing,healing and re-configuring for a distributed system. In this research we presented the emergent flocking behavior-based control. We defined the basis behavior and with variety of combination, and obtained a complex group behavior flocking. Unlike classical flocking, we implemented additional rules obstacle avoidance,formation and seek target which results in V-formation flocking while avoiding obstacles. We performed the visual simulation of our flocking algorithm using MATLAB. The results concluded that the multi-boid flock could successfully navigate to the target while avoiding collisions. This can be applied to areas where we need to maximize the coverage of sensors or minimize the risk of combative attack,both in military and civilian scenarios.
基金Funded by the National Natural Science Foundation of China(U1233107)Civil Aviation Science and Technology Innovation Project of China(MHRD20140210)
文摘Motion simulator usually appears the phenomenon of false cues and the workspace is limited in the process of washout. The proposed washout algorithm combines fuzzy logic control with the vestibular system to design the tilt coordination fuzzy adaptive filter, in order to minimize the vestibular sensory error below the human perception threshold. Owing to tilt coordination angular velocity limiter, the loss of low-pass acceleration must be compensated by the acceleration transform model. The translational channel decreases the possibility of the workspace beyond limitation and expands the scope of motion platform simulating input acceleration by using third-order filter. The simulation results show that the proposed algorithm can effectively overcome the phase retardation of classical washout algorithm, and then prevent the produce of false cues, decrease the displacement of motion platform simultaneously; in addition, white Gaussian noise simulates large variations in acceleration. The proposed washout algorithm can have maximal extreme value of acceleration and accurate simulating performance in general. It also proves that the proposed washout algorithm has a strong adaptability and reliability, which can effectively improve the dynamic fidelity for motion simulator.
文摘In order to improve the modernization level of sports comprehensive evaluation, a comprehensive evaluation method of sports modernization based on analytic hierarchy process (AHP) is proposed. An index analysis model for constructing the comprehensive evaluation of sports modernization is constructed, spatial modeling of information feature distribution is taken based on nonlinear time series analysis method for comprehensive evaluation of sports modernization, control objective function of comprehensive evaluation of sports modernization is constructed by analytic hierarchy process, optimal control parameters is obtained and comprehensive evaluation and optimization of sports modernization are realized. The simulation results show that the method is applied in comprehensive evaluation modem sports, it has performance of high reliability and good accuracy.
文摘The article presents multi-pattern formation exchange of mobile robots according to the image signals, programs motion paths using A* searching algorithm, and avoids the collision points of motion paths. The system contains an image system, a grid based motion platform, some wireless Radio Frequency (RF) modules and five mobile robots. We use image recognition algorithm to classify variety pattern formation according to variety Quick Response (QR) code symbols on the user interface of the supervised computer. The supervised computer controls five mobile robots to execute formation exchange and presents the movement scenario on the grid based motion platform. We have been developed some pattern formations according to game applications, such as long snake pattern formation, phalanx pattern formation, crane wing pattern formation, sword pattern formation, cone pattern formation, sward pattern tbrmation, T pattern formation, rectangle pattern formation and so on. We develop the user interface of the multi-robot system to program motion paths for variety pattern formation exchange according to the minimum displacement. In the experimental results, the supervised computer recognizes the various QR-code symbols using image system and decides which pattern formation to be selected on real-time. Mobile robots can receive the pattern formation command from the supervised computer, present the movement scenario from the original pattern formation to the assigned pattern formation on the motion platform, and avoid other mobile robots on real-time.
基金Supported by the Postdoctoral Science Foundation of China( No. 20100480964 ) , the Basic Research Foundation of Central University ( No. HEUCF100104) and the National Natural Science Foundation of China (No. 50909025/E091002).
文摘Based on the structure of Elman and Jordan neural networks, a new dynamic neural network is constructed. The network can remember the past state of the hidden layer and adjust the effect of the past signal to the current value in real-time. And in order to enhance the signal processing capabilities, the feedback of output layer nodes is increased. A hybrid learning algorithm based on genetic algorithm (GA) and error back propagation algorithm (BP) is used to adjust the weight values of the network, which can accelerate the rate of convergence and avoid getting into local optimum. Finally, the improved neural network is utilized to identify underwater vehicle (UV) ' s hydrodynamic model, and the simulation results show that the neural network based on hybrid learning algorithm can improve the learning rate of convergence and identification nrecision.
基金supported by National Nature Science Foundation under Grant Nos.60974041,60934006Research Fund for the Doctoral Program of Higher Education of China under Grant No.20090092110021
文摘This paper considers the formatiomshape control of three agents in the plane. By adding an adaptive perturbation to any agent's movement direction, a novel control strategy is proposed. It is shown that the proposed novel control law can not only guarantee the global asymptotical stability of the desired formation shape, but also ensure the collision avoidance of agents between each other. Simulation results are provided to illustrate the effectiveness of the control algorithm.
基金the National Natural Science Foundation of China(Nos.11132001,11272202 and 11472171)the Key Scientific Project of Shanghai Municipal Education Commission(No.14ZZ021)the Natural Science Foundation of Shanghai(No.14ZR1421000)
文摘Dynamic modeling and active control of a strap-on launch vehicle are studied in this paper. In the dynamic modeling, the double-compatible free-interface modal synthesis method is used to establish dynamic model of the system, and its model precision is compared with those of finite element method(FEM), fixedinterface modal synthesis method and free-interface modal synthesis method. In the active control, the swing angle of rocket motor is used as design variable, and the control law design based on the model of mass center motion is adopted to validate the system. Simulation results indicate that the double-compatible model synthesis method can properly approximate the FEM which is used as the benchmark solution, and the model precision of the double-compatible modal synthesis method is obviously higher than those of the fixed-interface and freeinterface modal synthesis methods. Based on the control law design, the deflection of mass center of the launch vehicle is very small.