FUZZY ADAPTIVE ACTUATOR FAILURE COMPENSATION DYNAMIC SURFACE CONTROL OF MULTI-INPUT AND MULTI-OUTPUT NONLINEAR SYSTEMS

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 with 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) approach with the backstepping design technique, 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.