Indirect adaptive fuzzy control for a class of nonlinear discrete-time systems

An indirect adaptive fuzzy control scheme is developed for a class of nonlinear discrete-time systems. In this scheme, the fuzzy logic systems are used to proximate unknown functions, and the unknown parameters are adjusted by time-varying dead-zone, which its size is adjusted adaptively with the estimated bounds on the approximation errors. The proposed design scheme guarantees that all the signals in the resulting closed-loop system are bounded, and the tracking error converges to a small neighborhood of the origin. Simulation results indicate the effectiveness of this scheme.