Adaptive fuzzy FTC design of nonlinear stochastic systems with actuator faults and unmodeled dynamics

This paper investigates an adaptive fuzzy control method for accommodating actuator faults in a class of uncertain stochastic nonlinear systems with both immeasurable states and unmodeled dynamics. The considered faults are modeled as both loss of effectiveness and lock-in-place. To deal with the immeasurable states, a novel state observer containing the actuator faults is designed. Combining with the backstepping technique and stochastic small-gain theorem, an adaptive fuzzy output feedback control method is developed. The presented design scheme can guarantee that the closed-loop system is input-to-state practically stable in probability. Finally, a simulation example is shown to verify the effectiveness of the proposed control method.