模糊滑动模态控制系统的动态性质分析

Dynamic Characteristics Analysis of Fuzzy Sliding Mode Control Systems

模糊控制在理论研究和实际应用中存在的问题是缺乏系统有效的设计方法 ,控制系统的稳定性及性能指标难以进行定量分析 ;模糊控制规则的数目随输入变量呈指数函数增加 ,控制器的设计变得很复杂 .为了解决上述问题 ,根据滑动模态控制理论 ,将模糊控制系统的输入量简化为广义跟踪误差的一个超平面 ,基于三角形的非线性划分语言变量的隶属度 ,得到了模糊控制系统的闭环传递函数 .基于此传递函数 ,对模糊控制器的内部机理和某些动态性质进行分析 ,得到了一些模糊控制器的设计参数与控制系统的上升时间、超调量、调整时间等的定量关系 .

There are two open problems of fuzzy logic control in scientific research and actual applications: one is lack of the effective systematic methodology to design the fuzzy control system,so it is difficult to analyze the stability and control properties;the other is that the number of control rules increases expo- nentially with the input variables of the control system.Hence,the controller's design becomes very com- plex.To solve those two problems,a methodology to reduce the input fuzzy sets with the hyperplane of generalized state errorwas discussed in this paper based on Sliding Mode Control( SMC) theory.A method of varying nonlinear fuzzy sets range using some parameter was proposed.A transfer function using these fuzzy member parameter was obtained.Based on this transfer function,some internal properties of fuzzy controller were analyzed to show that the fuzzy controller outperform the PD controller,such as the rise time,over- regulation,adjusting time.