An adaptive control law against time - varying delays in bilateral teleoperation systems

Bilateral teleoperation is a robotic system helping humans to work with the remote environment through a dual robot which includes a local robot and a remote robot operating with considerable time delays. In order to overcome this obstacle, beside the proposed wave variables and scattering approaches [1], [2], the conventional methods without wave variables has been pointed out in [3], [4] with constant time delay. In this paper, we propose a new adaptive control law based on Lyapunov's direct method to address time varying delays and position synchronization between two robots. In addition, force control was considered to guarantee tracking position error which converges to zero under humans and environment disturbances. The validity of them is based on theory and the good performance of the proposed controller shown in simulation results.