Adaptive Actuator Dead-Zone Compensation Control For Uncertain Noncanonical Fuzzy-Approximation Nonlinear Systems

Abstract

In the literature, most results of adaptive actuator dead-zone compensation for nonlinear systems are for unknown dynamic equations in certain canonical forms. Canonical form nonlinear systems have explicit relative degrees and their control schemes can be well constructed within the familiar backstepping design framework. For such systems, adaptive actuator dead-zone compensation has been investigated extensively. However, for noncanonical nonlinear systems (whose relative degrees are not explicit, and hence the backstepping design framework may not be applicable), there are important unsolved adaptive actuator dead-zone compensation control problems, for different types of systems. This paper develops a new adaptive control scheme for a representative class of uncertain noncanonical fuzzy-approximation nonlinear systems with unknown input dead-zones. Detailed design procedures are derived for both relative-degree-one and relative-degree-two systems. It is ensured that all closed-loop system signals are bounded, and the tracking error is small in the mean square sense. Simulation results confirm the effectiveness of the proposed control schemes.