Position tracking for bilateral teleoperation system with varying time delay

Teleoperation systems are widely used in several applications such as surgical robot and underwater vehicle. However, due to the long distance between the local and remote manipulators, time delay arises over the communication channel. The time delay can render the system unstable or certainly degrade the system performance. Nuno et al. proved that simple P-like controller can stabilize the teleoperator and provide position tracking under variable time delays. Moreover, they presented the condition under which the velocities and position error of a non-linear teleoperator are bounded. In this paper, it is proved, by analysis, simulation, and experiments, that the tracking condition, obtained by Nuno et al., is not always correct. Furthermore, a Lyapunov-like function is used in this research to obtain the correct tracking condition. Two identical Phantom Premium 1.5/6DOF devices shaped the experimental platform.