Adaptive fuzzy fault-tolerant dynamic surface control of nonlinear MIMO systems with actuator failures

This paper develops an adaptive fuzzy control method for accommodating actuator faults in a class of uncertain multi-input and multi-output (MIMO) nonlinear systems immeasurable states. The considered faults are modeled as both loss of effectiveness and lock-in-place (stuck at unknown place). With the help of fuzzy logic systems to approximate the unknown nonlinear functions, a fuzzy adaptive observer is developed for estimating the unmeasured states. Combining the dynamic surface control (DSC) technique with the nonlinear tolerant-fault control theory, a novel adaptive fuzzy faults-tolerant control (FTC) approach is constructed. It is proved that the proposed control approach can guarantee that all the signals of the resulting closed-loop system are semi-globally uniformly ultimately bounded (SUUB) and the tracking errors and observer errors converge to a small neighborhood of the origin. Simulation results are provided to show the effectiveness of the proposed approach.