On Robust Control of Nonlinear Teleoperators Under Dynamic Uncertainties With Variable Time Delays and Without Relative Velocity

This article proposed robust control algorithms to cope with dynamic uncertainties in nonlinear bilateral teleoperation system with variable time delays and without relative velocity. With the design of sliding mode control, the robust teleoperator is stable and the solutions are ultimately bounded if the control gains are contingent to the time delays. To tackle the requirement of relative velocity, another control algorithm is presented with the consideration of disturbance to show the robustness of the teleoperation system. Subsequently, the modified robust controller with exponential control terms is addressed to ensure position coordination and convergence of sliding vector in the proposed systems. Simulation and experimental results are illustrated to show the efficacy of the proposed robust controllers for nonlinear teleoperator, and the force information is acquired to demonstrate the performance of force reflection.