Design Of Controller And Study On Stability For Networked Teleoperation System

Teleoperation system have become an important tool for accomplishing tasks in remote or hazardous environments,such as outer space exploration,robotic remote detection,subsea operations,and surgery.A typical teleoperation system consists of five components: the human operator,the master robot,the communication channel,the slave robot,and the external environment.In the teleoperation system,the operator operates on the master robot,which is connected to the slave robot through a communication channel.Meanwhile,the slave robot tracks the master robot and performs the task.In this paper,the problem of trajectory tracking for networked teleoperation system is studied,as follows:1)An adaptive control strategy is proposed to track the trajectory of a nonlinear trilateral teleoperation system with symmetric time-varying delay.Firstly,assuming that the n-joint nonlinear manipulator is used as the master robot and the slave robot to perform tasks,the relevant nonlinear dynamic equations are established,and then the passive spring-damping system is used to simulate the forces exerted by the outside,and an adaptive controller is designed.Secondly,based on Lyapunov stability theorem,Barbalat lemma and adaptive control theory,the synchronization error of master-slave manipulator is asymptotically converged to zero,and the convergence speed and accuracy of the system are satisfied in practical applications.Finally,a simulation example is given to verify the accuracy and effectiveness of proposed control strategy.2)A control strategy is proposed for the trajectory tracking problem of nonlinear trilateral teleoperation system with constant time delay by combining adaptive control and neural network,and the controller design of free-moving trilateral teleoperation system is carried out.Firstly,in the case of acceleration measurability,a synchronization variable and an adaptive controller including position and velocity errors are constructed to ensure that the position and velocity tracking error between the trilateral teleoperation systems asymptotically converge to zero.In the case of unmeasurable acceleration,another synchronization variable is constructed and an adaptive controller is designed so that the same trajectory tracking performance for trilateral teleoperation system can be obtained.Second,combination of adaptive control and neural network is used to deal with the uncertainty and external interference of the teleoperation system.The asymptotic stability conditions of the trilateral teleoperation system are obtained by establishing a suitable Lyapunov-Krasovskii functional.Finally,the effectiveness of the designed control strategy is verified by simulation results.3)The constraint control problem of fixed time stability for nonlinear trilateral teleoperation system with time-varying delay was researched,the fixed time control strategy is proposed by combine nonsingular fast terminal sliding mode(NFTSM)control,adaptive control and neural network.Firstly,the constraint function of synchronization error is introduced and a new nonsingular fast terminal sliding mode(NFTSM)surface is designed.Second,combination of adaptive control and neural network is used to deal with the uncertainty and external interference of the teleoperation system.Based on the Lyapunov fixed-time stability theorem,the master-slave manipulator synchronization error converging to zero in the fixed time is proved.Finally,the simulation results verify the accuracy and effectiveness of the designed control strategy.