H∞ Variable universe adaptive fuzzy control for chaotic system

In the paper, an attempt is made to create the bridge between two important design techniques, i.e., H∞ control design and fuzzy control design, so as to supply H∞ control design with more intelligence and fuzzy control design with better robust performance. By Lyapunov method, the overall closed-loop system is shown to be stable. In the conventional adaptive fuzzy control system, the approximate error is not eliminated completely, so the accuracy of control is limited. In the study, the effect of both fuzzy logic approximation error and external disturbance on the tracking error is attenuated to a prescribed lever ρ by adequately selecting the weight factor r. The simulation results of the Duffing chaotic system are given to confirm the control algorithm is feasible for practical application.