Delay Compensation For Robot Teleoperation Systems

Teleoperation systems allow operators to interact with the remote environment where human is difficult to access or is dangerous for human being,so it expanded human perception and operational capabilities to ensure the safety of human beings.Now,teleoperation robot systems have a very broad application prospect in the fields of aerospace,deep sea exploration,military,nuclear industry,medical and so on.With the introduction of communication networks,the network-induced delay is inevitable which will deteriorate system performance,even destabilize the teleoperation systems.Therefore,it is very important to study the time delay problem for teleoperation systems.The delay compensation problem is investigated for teleoperation systems in this thesis,and the main contributions of the thesis are as follows:1.A delay compensation and control problem is investigated for a class of teleoperation system with single degree of freedom in the case of fixed time delay.In order to guarantee stability of the teleoperation system as well as reduce the sensitivity of the Smith predictor for model errors,a controller is designed by combining the active disturbance rejection technique and the Smith predictor.2.A delay compensation method based on communication disturbance observer is designed for teleoperation systems when the time delay is time-varying or uncertain.The dynamic caused by time delay is described as a network disturbance,then the communication disturbance observer is designed to estimate and compensate the disturbance.In order to increase the immunity and robustness,active disturbance rejection controller is adopted in the master side of the teleoperation system.Finally,the effectiveness of online delay compensation and stability control for the teleoperation system is validated through simulations.3.The motion synchronization control problem for teleoperation systems with time-varying delay is investigated.A controller based on generalized extended state observer is designed to ensure the stability of the teleoperation system as well as position synchronization of the manipulators.By feedback linearization,the nonlinear dynamics of the teleoperation system is modeled as a linear system with mismatched uncertainties.Then,the generalized extended state observer and the controller are designed to estimate and compensate the mismatched uncertainties caused by the network-induced delay.Finally,simulations are provided to demonstrate the effectiveness of the proposed controller design method.4.The force synchronization problem is investigated for teleoperation systems with asymmetric delay.Using the impedance model which is related to physics,the force feedback control problem is transformed to a position and velocity control problem.Then,the teleoperation controller based on generalized extended state observer is designed to realize force synchronization.