Model Predictive Control of transparent bilateral teleoperation systems under uncertain communication time-delay

Performance and stability degradation in teleoperation systems experiencing time delay in both forward and backward channels is of crucial importance. What is addressed in this paper is to propose a new control strategy using a modified Model Predictive Control (MPC) and a modified smith predictor. The MPC is in charge of the forward communication time delay by providing future control sequences. Also, the smith predictor compensates for the backward time delay. First, as a slave controller a simple discrete PD controller is designed for the slave system. Then, the system is reduced to a more general form to derive the future control sequences or namely to derive the master controller. Throughout the paper a low-pass unitary gain filter is used to improve the robustness of the teleoperation system under study. The design of a pre-filter highly reduces the overshoots imposed on the system.