精密平台磁敏智能隔振系统自适应PI控制研究

Adaptive PI control research for precision platform magnetic-sensitive intelligent vibration isolation system

为抑制精密平台存在的时变振动,提出一种基于磁流变弹性体(magneto rheological elastomer,MRE)半主动自适应比例积分(proportional integral,PI)控制方法。首先针对MRE隔振系统,建立其动力学模型,并根据MRE变刚度隔振原理,推导半主动控制条件;其次以响应加速度和目标加速度偏差作为PI控制器输入,通过遗传算法获得不同频率、幅值激励下的最优PI控制参数,并基于被动参考模型获得频率幅值依赖自适应律。该方法无须通过复杂的傅里叶变换辨识频率,实时性高;最后通过仿真和试验验证了所设计控制器的有效性;结果表明,与传统PI控制器相比,自适应PI控制器对40~50 Hz、1.0~3.0 m/s^(2)时变振动具有更大的抑制。

To suppress time-varying vibrations in precision machining processes,a semi-active adaptive PI control method based on magnetorheological elastomer(MRE)was proposed.Firstly,the dynamic model of the MRE isolation system was established based on the variable stiffness isolation principle,and then the semi-active control conditions were derived.Secondly,taking the response acceleration and target acceleration deviation as the input of the PI controller,the optimal PI control parameters under different vibration frequencies and amplitudes were optimized by a genetic algorithm,and the frequency amplitude dependent adaptive law was obtained based on the passive reference model.This method does not need to identify the frequency by complicated Fourier transform,and has high real-time performance.Finally,the effectiveness of the designed controller was verified by simulation and experiment.The results show that compared with the traditional PI controller,the proposed method has greater suppression at 40~50 Hz and 1.0~3.0 m/s^(2) time-varying vibration.