Robust output regulation for a class of MIMO nonlinear systems with uncertain exosystems

The robust output regulation problem is considered for a class of multi-input multi-output (MIMO) nonlinear systems with uncertain exosystems. Under a mild assumption that the uncertainties of the controlled plant and exosystem have known boundary functions, a new design method of dynamic variable structure controller is proposed. It is proven that the tracking error of the closed-loop system can reach a specified manifold in a finite time and converge to zero asymptotically while all states involved are bounded. Simulation results of a permanent magnet synchronous motor servo system are given to validate the proposed approach.