Adaptive fuzzy sliding mode control for MIMO nonlinear systems subject to actuator faults and external disturbances

A class of MIMO unknown nonlinear systems subject to uncertain actuator faults and external disturbances is studied in this paper using fuzzy approximation theory and sliding modes. Using the universal approximation theorem, an adaptive fuzzy control law is proposed to accommodate the uncertain actuator faults during operation. The considered faults are modeled as both loss of effectiveness and lock-in-place (stuck at some unknown place). Thanks to sliding mode technique, we proved that the proposed control scheme can guarantee that all signals of the closed-loop system to be semi-globally uniformly ultimately bounded and the convergence of the tracking error. A simulation example is presented to show the efficiency of the proposed approach.