A nonlinear regulator scheme using sliding mode for SISO nonlinear systems

A robust control scheme for the output tracking of SISO (single input, single output) nonlinear systems is proposed. The scheme is based on the nonlinear regulator theory and the sliding mode approach. The basic idea consists of designing a nonlinear regulator-based controller and then modifying it by defining a subset of the state space, called a sliding surface, on which the tracking error goes asymptotically to zero. It is found that, under certain conditions, the sliding controller forces the system to reach the sliding surface when perturbations on the plant occur, hence obtaining a tracking error that, in the mean, asymptotically tends to a sufficiently small region around zero. An illustrative example is given