FUZZY DIRECT ADAPTIVE-CONTROL FOR A CLASS OF DECENTRALIZED NONLINEAR-SYSTEMS

In this paper, a stable fuzzy direct control scheme is presented for a class of interconnected nonlinear systems with unknown nonlinear subs ystems and unknown nonlinear interconnections. In this control algorit hm, fuzzy logic systems are employed to approximate the optimal contro llers, which are designed on the assumption that all dynamics for each subsystem are known; then the fuzzy controllers and adaptation mechan isms for each subsystem depend only on local measurements to provide a symptotic tracking of a reference trajectory. In addition, a fuzzy sli ding mode controller is developed to compensate for the fuzzy approxim ating errors and attenuate the interactions between subsystems. Global asymptotic stability is established in the Lyapunov sense, with the t racking errors converging to a neighborhood of zero. A simulation exam ple is given to illustrate the performance of the proposed method.