Control of a bilateral teleoperation system in the presence of varying time delay, model uncertainty and actuator faults

This paper presents a novel scheme for robust controller design for a bilateral teleoperation system in the presence of asymmetric varying time-delay in the communication channel, parametric uncertainty in nonlinear model of manipulators, and actuator faults. First, a passive Fault Tolerant Control law is proposed for nominal system. Then, by using the Lyapunov–Krasovskii theorem, sufficient stability conditions of real and faulty system are obtained to tune the controller parameters. The main contribution of the proposed method is that it can assure the stability, position and force tracking in the presence of bias fault and partial failure in actuators of nonlinear teleoperation system, simultaneously. Also, the developed controller is fixed-structure which can be implemented easily in practice, without any need to identification of system parameters or fault estimation. Simulation and experimental results are presented to demonstrate the effectiveness of the proposed approach.