Abstract: The performance and stability of bilateral teleoperation system are easily degraded by time delay and uncertainty factors. In order to solve this problem, a new control structure is proposed concerning different task characteristics of master and slave sides. Because the master-side is vulnerable to disturbance in the realization of force feedback, a kind of nonlinear disturbance observer is designed for online estimate and compensation. At the slave-side, impedance control based on sliding mode is applied to ensure precise position tracking and desired interacting with the environment. The Liewellyn absolute stability criterion is adopted to derive stability condition and parameter selection criteria under a time delay. The proposed method is validated by experiments with a single-DOF teleoperation platform, and the results show that the proposed method can improve operational performance while having good robustness.

Key words: Absolute stability criterion, Bilateral teleoperation, Disturbance observer, Impedance control, Time delay