This paper proposes an intelligent controller for motion control of robotic systems to obtain high precision tracking without the need for a real-time trial and error method.In addition, a new self-tuning algorithm ha...This paper proposes an intelligent controller for motion control of robotic systems to obtain high precision tracking without the need for a real-time trial and error method.In addition, a new self-tuning algorithm has been developed based on both the ant colony algorithm and a fuzzy system for real-time tuning of controller parameters. Simulations and experiments using a real robot have been addressed to demonstrate the success of the proposed controller and validate the theoretical analysis. Obtained results confirm that the proposed controller ensures robust performance in the presence of disturbances and parametric uncertainties without the need for adjustment of control law parameters by a trial and error method.展开更多
To solve the problems that the exception handling code is hard to test and maintain and that it affects the robustness and reliability of software, a method for evaluating the exception handling of programs is present...To solve the problems that the exception handling code is hard to test and maintain and that it affects the robustness and reliability of software, a method for evaluating the exception handling of programs is presented. The exception propagation graph （EPG） that describes the large programs with exception handling constructs is proposed by simplifying the control flow graph and it is applied to a case to verify its validity. According to the EPG, the exception handling code that never executes is identified; the points that are the most critical to controlling exception propagation are found; and the irrational exception handling code is corrected. The constructing algorithm for the EPG is given; thus, this provides a basis for automatically constructing the EPG and automatically correcting the irrational exception handling code.展开更多
Purpose-The purpose of this paper is to design a global robust and continuous control scheme for the attitude tracking control problem of the reentry vehicle with parameter uncertainties and disturbances.Design/method...Purpose-The purpose of this paper is to design a global robust and continuous control scheme for the attitude tracking control problem of the reentry vehicle with parameter uncertainties and disturbances.Design/methodology/approach-First,feedback linearization is applied to the model of reentry vehicle,resulting in three independent uncertain subsystems.Then a new second-order time-varying sliding function is proposed,based on which a continuous second-order time-varying sliding mode control(SOTVSMC)law is proposed for each subsystem.The global robustness and convergence performance of the closed-loop reentry vehicle control system under the proposed control law are proved.Findings-Simulation is made for a reentry vehicle through the assumption that there is external disturbance to aerodynamic moment and the aerodynamic parameters as well as the atmospheric density are perturbed.The results verify the validity and robustness of the proposed strategy.Originality/value-The SOTVSMC attitude controller based on feedback linearization is proposed for the reentry vehicle.The advantages of the proposed SOTVSMC are twofold.First,the global second order sliding mode is established,which implies that the closed-loop system is global robust against matched parameter uncertainties and disturbances in reentry.Second,the chattering problem is significantly alleviated.展开更多
文摘This paper proposes an intelligent controller for motion control of robotic systems to obtain high precision tracking without the need for a real-time trial and error method.In addition, a new self-tuning algorithm has been developed based on both the ant colony algorithm and a fuzzy system for real-time tuning of controller parameters. Simulations and experiments using a real robot have been addressed to demonstrate the success of the proposed controller and validate the theoretical analysis. Obtained results confirm that the proposed controller ensures robust performance in the presence of disturbances and parametric uncertainties without the need for adjustment of control law parameters by a trial and error method.
基金The National Natural Science Foundation of China(No60503020)the National Basic Research Program of China (973Program) (No2002CB312000)+1 种基金the Natural Science Foundation of Jiangsu Province (NoBK2006094)the Science Research Foundation of China University of Mining and Technology
文摘To solve the problems that the exception handling code is hard to test and maintain and that it affects the robustness and reliability of software, a method for evaluating the exception handling of programs is presented. The exception propagation graph （EPG） that describes the large programs with exception handling constructs is proposed by simplifying the control flow graph and it is applied to a case to verify its validity. According to the EPG, the exception handling code that never executes is identified; the points that are the most critical to controlling exception propagation are found; and the irrational exception handling code is corrected. The constructing algorithm for the EPG is given; thus, this provides a basis for automatically constructing the EPG and automatically correcting the irrational exception handling code.
基金supported by National Natural Science Foundation of China under grant 61104153Major State Basic Research Development Program under grant 2012CB720000Research Fund for the Doctoral Program of Higher Education of China under grant 20091101110025.
文摘Purpose-The purpose of this paper is to design a global robust and continuous control scheme for the attitude tracking control problem of the reentry vehicle with parameter uncertainties and disturbances.Design/methodology/approach-First,feedback linearization is applied to the model of reentry vehicle,resulting in three independent uncertain subsystems.Then a new second-order time-varying sliding function is proposed,based on which a continuous second-order time-varying sliding mode control(SOTVSMC)law is proposed for each subsystem.The global robustness and convergence performance of the closed-loop reentry vehicle control system under the proposed control law are proved.Findings-Simulation is made for a reentry vehicle through the assumption that there is external disturbance to aerodynamic moment and the aerodynamic parameters as well as the atmospheric density are perturbed.The results verify the validity and robustness of the proposed strategy.Originality/value-The SOTVSMC attitude controller based on feedback linearization is proposed for the reentry vehicle.The advantages of the proposed SOTVSMC are twofold.First,the global second order sliding mode is established,which implies that the closed-loop system is global robust against matched parameter uncertainties and disturbances in reentry.Second,the chattering problem is significantly alleviated.
