Impedance control with variable damping for bilateral teleoperation under time delay

This paper proposes a new impedance controller that is to be applied to bilateral teleoperation under a time delay. The controller has a variable damping designed to achieve a good tacking performance and contact stability concurrently. The damping of the slave impedance is modulated based on the distance between the slave and its environment. The stability of the teleoperation system including the human operator and the environment is analyzed using the absolute stability. The validity of the proposed control scheme is demonstrated in experiments with a 1-DOF teleoperation system. The experimental results show that the system performs better with a damping modulation than with a constant damping or with a variable damping, which changes based on contact signals.