Research On Transient-state And Steady-state Performance Constrained Control For Teleoperation System With Network-induced Time Delay

As a remote manipulation system,networked teleoperation system can maximize the respective abilities of human being and mechanical equipment.Nowadays,the teleoperation system has embraced many applications such as nuclear accident rescue,space exploration,undersea operation and robotic telesurgery.Unfortunately,there are many restrictions for the teleoperation system in practical application.On one hand,the information communication between master and slave is inevitably influenced by the limited communications bandwidth.On the other hand,the teleoperation system has strong nonlinearity,the system model and parameters are always uncertain.Moreover,the system model is disturbed by the task environment easily.In addition,due to the extension of applied range and the increasement of task complexity,the performance demand on the teleoperation control is increasing.In this thesis,considering the prescribed transient-state and steady-state performance constraints,several novel control algorithms are designed for the nonlinear teleoperation system with complex network environment and severe task environment.Thus the control performances on rapidity,robustness and accuracy can be guaranteed simultaneously.The non-smooth control theory and prescribed performance control theory are expanded in this thesis.Moreover,the finite time control problem and prescribed performance control problem are firstly solved for networked teleoperation system with network-induced time-varying delays in the absence of exact information on time delays.The main research works are summarized as follows:Firstly,considering the finite time and zero error steady-state performance constraint,the researches on the teleoperation with network-induced constant and time-varying delays are conducted thoroughly.The synchronization errors between the master and the slave are guaranteed to converge to zero in finite time by designing new non-smooth control schemes.Under constant time delay,based on terminal sliding mode(TSM)method,the finite time control design problems are investigated with state-feedback and output-feedback systematically.Two novel nonsingular fast terminal sliding mode(NFTSM)surfaces are constructed.Then the singularity problem existing in generalterminal sliding mode control(TSMC)is solved.Moreover,a new fast finite time velocity observer is designed based on the TSM technique.Then the slow observation speed and the limited observation ability of general velocity observers can be remedied.In the case with time varying delays,a new finite time control strategy is proposed in the absence of exact information on the time delays.In addition,a new fast finite time parameter adaptive estimation method is proposed.Then the uncertain system parameters can be estimated online in finite time.Furthermore,the system stability condition on controller parameters and the upper bound of time delays' derivatives is built,then the conservative of the teleoperation system is reduced.Secondly,the transient-state and steady-state with bounded errors performance constraints control problems for the teleoperation system with network-induced constant and time-varying delays are considered.New prescribed performance control strategies are proposed based on system performance constrained function.Under constant time delay,a new prescribed performance control is designed with the backstepping method.Then with the new control scheme not only the asymptotic convergence but also the requirements on the system overshoot,convergence speed,convergence precision can be achieved.In addition,a new adaptive prescribed performance control algorithm is also constructed.With the adaptive terms,the prescribed system performances can be ensured for the teleoperation system under actuator saturation.Moreover,the prescribed performance control problem for teleoperation system with time-varying delays is solved by employing the multi-dimensional small-gain theorem successfully.The relationship on controller parameter,system performance function parameters,upper bound of time delays' derivatives and the system stability is also given.Thus the theoretical basis of tuning parameters of controller and system performance function is provided.Finally,the transient-state and finite time zero error steady-state performance constraints control problem is addressed for the teleoperation system with network-induced constant time delays.A new terminal sliding mode control algorithm is designed with the disturbance observer technique,thus the finite time convergence performance can be guaranteed for the teleoperation system with system uncertainties.A new error transformation variable is constructed by introducing new error constrainedfunctions.Furthermore,a new finite time disturbance observer is developed to compensate the influences of system uncertainties and external disturbances in finite time.Additionally,a new finite time control scheme is proposed based on NFITSM technique.The finite time convergence of the closed-loop teleoperation system is proved by applying the Barrier Lyapunov function(BLF).Therefore,the multiple control objectives on system overshoot,convergence speed,convergence accuracy and so on are guaranteed with the proposed control algorithm.Simulation results are presented to illustrate the rationality and effectiveness of the proposed control strategies.Comparison simulation results demonstrate the superiority of the novel control algorithms over existing methods.Besides,experimental results verify the practicability of the designed controllers.