Adaptive Fuzzy Control for a Class of Nonlinear MIMO Time-Delayed Systems with Unknown Dead-Zone Input

The problem of adaptive fuzzy control for a class of MIMO time-delayed nonlinear systems with unknown dead-zone is discussed in this paper. Based on the principle of sliding mode control , using the fuzzy systems with linear adjustable parameters which are used to approximate plant unknown functions, a novel design scheme of adaptive fuzzy controller is proposed. With the help of a supervisory controller, the resulting closed-loop system is globally stable in the sense that all signals involved are uniformly bounded. Furthermore, the adaptive compensation terms of the approximation errors are adopted to minimize the influence of modeling errors and parameter estimation errors. In addition, the approach does not require the dead-zone model parameters and parameters in the lumped uncertainty to be known constants. By theoretical analysis, the closed-loop control system is proved to be globally uniformly ultimately bounded with tracking errors converging to zero. Simulation results demonstrate the effectiveness of the approach.