Optimal Adaptive Fuzzy Composite Control

Combining fuzzy control with classical control and modern control is of theoretical and practical significance. That is a very important direction of development of fuzzy control and a hotspot of research fuzzy system, because it can achieve complementarity of fuzzy control and other control scheme. In this paper a hybrid fuzzy-linear output tracking control schemes is developed for a class of nonlinear system. It consists of an indirect adaptive fuzzy controller, which is constructed by modeling the unknown part of system, and adaptive law given by using Lyapunov synthesis approach. Since the fuzzy descriptions are imprecise and may be insufficient to achieve the desired accuracy, it is necessary to design a compensator to removing the influence of the approximation error. So a compensator is constructed, which is compensates the approximation error's effect on system output at the condition of the approximation error thought as disturbance of the system. Finally. It is proved that the proposed control scheme can not only guarantee the asymptotic stability of the closed-loop, but also satisfy the requirement of H∞ performance index. The simulation results demonstrate and confirm the theoretical results.In addition, we give the universal control scheme for single-in-single-out nonlinear systems in this paper. The controller for longitudinal short period model of aircraft has been designed and simulated by using those schemes. Simulation results are demonstrated to show that the scheme is not only simpleness and easy accomplish, but also enhance the performance of flight and the effectiveness and applicability of the proposed method.