L2 stable transparency optimized two channel teleoperation under time delay

This paper presents a novel two channel control law for high transparency teleoperation under time delay with guaranteed delay independent L₂ stability. Four channel controllers have long been known to provide transparent teleoperation when time delay does not exist on the communication channels. However under time delay, a trade-off between delay and transparency must be made to make the system stable. Previously, four channel controllers with damping injection have been proposed to realize this trade-off. However, when using four channels the compromise in transparency is not ideal. In this paper, by introducing a two channel control architecture with damping injection and force reflection filters we realize an L₂ stable teleoperation system with better transparency/performance compared to the four channel teleoperation systems under time delay. The validity of our approach is confirmed theoretically and by experiments.