叠堆式压电陶瓷驱动器的复合控制

提出了逆Bouc-Wen前馈控制与反馈控制相结合的复合控制算法,用于改善压电陶瓷驱动器对目标轨迹的跟踪性能。建立了压电陶瓷驱动器的Bouc-Wen迟滞动力学模型,并用粒子群算法(PSO)对该模型的参数进行识别。基于Bouc-Wen迟滞模型,提出了逆Bouc-Wen前馈补偿控制。最后,为消除迟滞模型的不确定性,引入比例积分(PI)反馈控制,并与前馈补偿控制构成复合控制算法。建立了基于dSPACE实时系统的压电陶瓷驱动实验平台,迟滞实验结果表明:压电陶瓷的迟滞误差量几乎为0,线性度高达96.5%;目标轨迹跟踪实验结果表明:复合控制算法的最大跟踪误差为0.180 5μm,均方根(RMS-Root mean square)跟踪误差为0.055 4μm,跟踪精度达到了10-8 m。相比于开环控制、前馈控制及PI反馈控制,提出的复合控制算法能够基本消除压电陶瓷的迟滞非线性,同时具有很好的轨迹跟踪性能。

Feed-forward control of stack piezoelectric actuator

A novel inverse feedforward control algorithm was developed based on inverse Bouc-Wen feed-forward control and feedback control for improving the trajectory tracking performance of a Piezoelectric Actuator (PEA). A Bouc-Wen hysteresis dynamic modeling for the PEA was established, and system parameters of the Bouc-Wen model were identified by Particle Swarm Optimization (PSO) method. Then, a feed-forward compensation control method was proposed based on hysteresis Bouc-Wen model. Finally, the inverse feed-forward control method combining the PI feedback control with feed-forward control were proposed to control the piezoelectric actuator. An experimental platform was developed based on dSPACE system. The hysteresis experiment results show that the hysteresis error and relative linearity of the proposed method is almost zero and 96.5%, respectively. The trajectory tracking experimental results show that the maximum tracking error and RMS tracking error of the proposed method are 0.180 5 μm and 0.055 4 μm, respectively, obtaining the high tracking performance by 10^-8 m. As compared with open loop control, feedforward control, PI feedback control, the proposed inverse feedforward control algorithm compensates basically hysteresis nonlinearity of the PEAs and shows good trajectory tracking performance.