Observer design for bilateral teleoperation systems with variable time delays

Abstract

Bilateral teleoperators allow people to perform complex tasks in a remote or inaccessible environment. Since the local and remote manipulators are connected via a communication channel there may be substantial delays in data transmission, which does not allow neither exact tracking position nor transparency. For this reason, most control approaches are meant to guarantee only position regulation, when a human interacts with the local robot, or to synchronize the local and the remote manipulator by inducing periodic position trajectories. Another problem that may be present is the lack of velocities measurements. In this work, a teleoperation control-observer scheme is proposed for bilateral systems with variable delays. It is shown that the observation errors tend to zero while position consensus or synchronization is achieved in free motion. Simulation results are provided to validate the proposed algorithm.