Variable structure model following control with robust stability

In this paper, a variable structure model following control system (VSMFCS) for robot manipulators is proposed. By using a function augmented sliding hyperplane, the proposed controller guarantees that the system is always in the sliding mode. Therefore, although the conventional VSMFCS methods have been able to ensure the asymptotic stability of the overall system, the proposed scheme can guarantee the globally exponential stability even though the controller does not use the model state (x_m)