基于模糊逻辑的复杂控制系统自适应鲁棒控制器设计

Adaptive Robust Controller Design for Complex Systems Based on Fuzzy Logic Systems

利用模糊逻辑系统具有充分利用语言信息和逼近连续函数的性质 ,分析设计了复杂大系统的自适应鲁棒控制器和模糊逻辑系统参数估计的自适应律 ,这种控制器使被控系统的状态及参数估计误差一致终极有界。仿真实例表明 ,所提出的方法是有效的。

Refs. 1 through 3 all dealt with robust control for complex systems with uncertainties but they all require that the bounded functions of uncertainties be known, or some strict hypotheses be made, thus limiting their application in engineering. We overcome the shortcomings by employing a fuzzy logic system that can approximate any continuous function with arbitrary exactness. In section 2 we synthesize the parameters, adaptive laws and controllers for a class of complex systems with uncertainties, whose bounded functions are unknown. Through centralizing the uncertainties of the systems to be controlled, only one fuzzy logic system is needed, which simplifies the complexity of controllers. An important feature of our design method as described in section 2 is that the synthesized controllers directly depend on the output of fuzzy logic system. We draw the conclusion that, under some simple conditions, the adaptive laws and controller can ensure both the states of the systems to be controlled and the parameter estimate errors to be uniformly ultimately bounded (UUB). In section 3 we carried out simulation of a system composed of three subsystems. Simulation results as given in Figs. 1 and 2 show the validity of our method.