磁轴承的遗传优化的变论域模糊PID控制

Variable universe fuzzy PID control based on genetic optimization for magnetic bearings

针对高速磁悬浮轴承在系统回到稳定过程中存在非线性、响应速度慢、超调量大的问题,文中首先经遗传算法对PID的三个初始参数进行离线优化,再利用变论域模糊PID的控制方法,通过选用能够使论域伸缩而优化了控制规则的合适伸缩因子,经模糊控制器输出PID的3个调整参数。将两种PID的3个参数值相结合得到PID最终参数,进行对磁悬浮轴承系统控制。经过Simulink仿真,结果表明经遗传优化的变论域模糊PID控制器控制精度高,调节速度快,约在0.02 s处达到稳定,超调量小,在0.18 s处突加改变负载的一个扰动,系统能够快速反应,用时约0.03 s恢复到稳定。

Since the nonlinearity,slow response and large overshoot occur to the high-speed magnetic bearing system when it is in the process of return to stable state,the three initial parameters of PID are optimized offline by genetic algorithm first,and then the variable universe fuzzy PID control method are utilized to output the 3 adjustment parameters of PID via the fuzzy controller by selecting the appropriate expansion factor which can make the universe expand for the optimization of the control rules.The3 parameter values of two kinds of PIDs are combined to get the final parameters of the PID to control the magnetic bearing system.The results of simulation with Simulink show that the variable universe fuzzy PID controller after genetic optimization has high control precision,high regulation speed(return to stable state at about 0.02 s)and small overshoot.When a disturbance changing the load is suddenly added at 0.18 s,the system can react quickly and recover to the stable state in about 0.03 s.