Adaptive fuzzy control for unknown nonlinear systems with perturbed dead-zone inputs

Adaptive fuzzy control is used to control a class of unknown nonlinear systems with perturbed dead-zone inputs in this paper. A new dead-zone actuator model which contains time-varying and perturbed actuation gain is proposed. The dead-zone nonlinearity is treated as a linear-like term, a nonlinear term, and a disturbance-like term, by which the robustness of the system can be obtained by less control effort. Backstepping technique combined with nonlinearly parameterized fuzzy approximators is employed to derive the controller, which removes the restriction that fuzzy basis functions must be well-known for control design. It is proved in theory that the proposed controller guarantees the stability and desired tracking performance of the closed-loop system. A simulation example is also included to demonstrate the effectiveness of the controller. Copyright © 2010 Acta Automatica Sinica. All rights reserved.