Adaptive fuzzy controller design for a class of uncertain nonlinear MIMO systems

A combined adaptive fuzzy output feedback control scheme is presented for a class of multiple-input–multiple-output (MIMO) nonlinear systems with the unmeasured states. A state observer is used to estimate the unmeasured states of the systems. The resulting closed-loop system consists of the state observer and four control components, where the control components are the combined adaptive fuzzy controller, supervisory controller, H∞ robust control item and auxiliary compensation item. Compared with the existing results in the observer design, the main advantages of this scheme are that (1) the combined adaptive fuzzy control item, which can trade off the fuzzy descriptions for controlled object rules and control action rules, is designed in the controller; (2) the proposed controller has the supervisory control performance. The stability of the closed-loop system is analyzed by using Lyapunov analysis method. Simulation results validate the effectiveness of the proposed control scheme.