精密机床的模糊PID主动隔振系统研究

Study on an Active Vibration Isolation System with Fuzzy PID Control for Precise Machine Tool

针对外界振动影响精密机床加工精度的问题,在二级隔振系统的基础上,采用超磁致伸缩作动器作为执行机构,建立系统的动力学模型。根据精密机床的加工工况复杂多变的特点,提出采用模糊PID控制方法对机床的振动干扰进行主动控制。通过MATLAB/Simulink搭建隔振系统的仿真模型,分析比较被动隔振、采用PID控制和引入模糊PID控制时的隔振效果。仿真结果表明,模糊PID主动隔振系统具有更好的隔振效果,其相对被动隔振的稳定时间短,对低频干扰信号的隔离效果好;相对PID控制对系统参数变化的适应性强。

Due to the fact that environmental vibration can reduce the processing accuracy of precise machine tool, a giant magnetostrictive actuator was used as an executive mechanism to the double-stage vibration isolation system. A dynamic model of the system was established. Since the machining process was complicated and changeable, the Fuzzy PID control method was applied to the active vibration isolation system. By means of MATLAB/Simulink software, the simulation model of the vibration isolation system was built. The isolation effects of passive vibration isolation, PID control and Fuzzy PID control was compared. The simulation results show that the active vibration isolation system with Fuzzy PID control has a better vibration isolation effect than the others. It＇s settling time is shorter and isolation effect is better for low- frequency signals compared with the passive vibration isolation. While compared with PID control, the Fuzzy PID control is more adaptable to the system parameter change.