Design of a Composite State Convergence Controller for a Nonlinear Telerobotic System

This paper presents the design of a reduced complexity state convergence controller, termed as composite state convergence controller, for a single degree-of-freedom nonlinear telerobotic system. First, nonlinear master and slave models are feedback-linearized and composite states are formed by combining their respective position and velocity signals. These composite master and slave states along with the operator's force are then transmitted across the communication channel instead of full states. In this way, the complexity of communication structure is reduced. An augmented system composed of composite master and slave states is finally constructed and method of state convergence is applied to compute the control gains of the proposed scheme. It is shown that position and velocity states of the master and slave systems still converge in the absence and presence of time delays, even though the design is based on the reduced order composite system. The validity of the proposed scheme is confirmed through MATLAB simulations as well as semi-real time experiments.