压电陶瓷执行器多模时变滑模逆补偿控制

摘要

针对压电陶瓷执行器的迟滞问题,设计多模时变滑模逆补偿控制器对压电陶瓷执行器进行控制.首先,利用Preisach逆模型对迟滞进行串级补偿.然后,针对补偿后的压电陶瓷执行器,设计滑模变结构控制.为了消除滑模控制的到达过程,采用带指数项的滑模面.为了消除系统的静态误差,同时也减小超调,设计一个普通时变滑模面和一个带积分项的时变滑模面,采用多模控制的思想对所设计的两个滑模控制进行切换.并且通过模糊控制方法确定两个滑模控制器的切换时刻.另外,用滑模面代替切换函数有效地消除了抖振.实验结果表明,所采用的多模时变滑模逆补偿控制,消除了滑模控制的达到阶段和抖振,两个滑模控制平滑切换,克服了压电陶瓷执行器的迟滞非线性,提高了控制精确度,跟踪的平均绝对误差为0.0135 μm.%In order to reduce the hysteresis of piezoceramic actuator (PA) , a multi-mode time-varying sliding mode control (TVSMC) of the PA based on the inverse compensation was desiged to control the PA. Frist, an inverse preisach model was established to compensate the hysteresis. Then a sliding mode control (SMC ) has been used to control the PA after the compensation. In order to eliminates the reaching phase of the SMC, a time-varying sliding surface has been choosed. To eliminate static error and control the overshoot, two SMC controllers have been designed. And the two controllers form a Multi-mode controller. The switching time of the Multi-mode controller obtained through a fuzzy controller. Also, the switch fuction of the SMC has been replaced by the sliding surface. The experimental results show that the designed control strategy eliminates the reaching phase and the chattering of the SMC; Smoothly switching has been implemented between two SMC controllers; The precision has been improved, and the average absolute error is 0.0135 μm.