ROBUST BILATERAL TELEOPERATION CONTROL UNDER UNKNOWN CONSTANT TIME DELAY WITHOUT VELOCITY MEASUREMENTS

New technological advancements in the communication channel of time delay teleoperation systems have attracted lot of attention, which have produced recently new control schemes, under a variety of conditions, including unknown (either constant or time varying) time delay or parametric uncertainty. However, those require full access to the state of the master and slave robot. In this paper, a model free, exact differentiator, is used to estimate the full state under parametric uncertainty together with a chattering free, second order sliding mode controller to guarantee robust impedance tracking under constant, but unknown, time delay. Experimental results, that validate the predicted behavior, are presented and discussed.