磁悬浮系统的模糊自适应PID控制

Fuzzy adaptive PID control in magnetic levitation system

针对磁悬浮系统开环不稳定、强烈非线性等特性,结合PID控制和模糊控制的优点,提出一种改进的模糊自适应PID控制方法(IFPID)。将微分环节从模糊控制器中剥离出来,只对比例和积分参数进行模糊整定。设计时采用非线性模糊化,利用S-函数建立磁悬浮系统的非线性模型并进行仿真。仿真结果表明,IFPID控制系统的抗干扰和适应参数变化的能力都优于常规PID控制,具有较好的动态特性和稳定性。

Combining the advantages of PID controller and fuzzy controller, an improved fuzzy adaptive PID controller （IFPID） was proposed according to the characteristics of maglev system, such as open-loop instability and strong nonlinearity. The algorithm of IFPID controller was analyzed and designed theoretically by nonlinear fuzzy mapping. D controller was separated from PID controller which P and I parameters were adapted by fuzzy controller. And the nonlinearity model of maglev system which was programmed by S-function was simulated. The results shows that the IFPID controller has the advantages of higher anti-interference ability and adaptability to parameters＇ changing than conventional PID controller, and better dynamic property and stability.