Robust four channel teleoperation under time delay by damping injection

This paper presents an augmented 4 channel architecture for stable teleoperation under time delay by using damping injection on each robot. The 4 channel architecture is optimized for good performance, but can easily become unstable under delay. By introducing local damping to the robots, we can obtain a 4 channel teleoperation architecture which is more robust against time delays. By using the hybrid matrix and the network stability parameter based on Llewelleyn´s Absolute Stability criterion, we show that local damping makes the 4 channel teleoperation much more stable even under time delay. We also analyze the transparency of this system. Furthermore we confirm the validity of our approach with experiments on a teleoperator system which is stable under time delay.