Higher-order sliding mode impedance bilateral teleoperation with robust state estimation under constant unknown time delay

Time delay teleoperation systems have gained gradual acceptance due to technological advancements, in particular in its communication channel, however, it is difficult to measure in real time the time delay. In this schemes, slave teleoperators are in contact to rigid environments, wherein slave control requires fast, robust and free of chattering control, thus making first order sliding mode teleoperation control unsuitable. As an alternative, chattering free, higher-order sliding mode teleoperator control is proposed in this paper to guarantee robust tracking under constant, but unknown time delay. Moreover, complete order sliding mode observers are proposed to avoid measurement of velocity and acceleration. Simulations are presented and discussed, which show robust impedance tracking