压电执行器非对称磁滞动态建模和辨识

Modeling and Identification of Asymmetric Hysteretic Dynamics in Piezoelectric Actuators

针对压电执行器的磁滞非线性以及动态建模问题,通过非对称算子和多项式的结合,提出了改进的Prandtl-Ishlinskii(PI)磁滞模型,以更好地描述压电材料的非对称磁滞现象,在此基础上构建了系统的磁滞动态模型,包括功放电路模型、机械系统模型和磁滞模型三部分,给出了模型参数的辨识方法,利用不同信号分三步依次辨识功放电路、机械系统以及压电磁滞特性的模型参数,以解决其耦合问题。实验结果表明,当输入为缓变信号时,模型预测误差的均方根和最大值分别为0.065μm和0.2μm,提出的非对称磁滞动态模型比纯线性模型和动态模型的模型吻合度高16%以上,当输入为高频信号时,其吻合度比磁滞模型约高6.64%。

In view of the hysteresis nonlinearity of piezoelectric actuators and dynamic modeling problem,through the combination of asymmetric operator and polynomial,proposed to improve the Prandtl-Ishlinskii(PI)hysteresis model,in order to better describe the asymmetric hysteresis phenomenon of piezoelectric materials,on the basis of constructing the system of dynamic hysteresis model,including the power amplifier circuit model,the mechanical system model and the hysteresis model of three parts,model parameter identification method is given,using three different signal identification in turn power amplifier circuit,mechanical system and the characteristics of electromagnetic pressure hysteresis model parameters,in order to solve the coupling problem.The experimental results show that when the input is a slow-varying signal,the root-mean-square and maximum value of the model prediction error are respectively 0.065μm and 0.2μm.The proposed asymmetric hysteresis dynamic model is more than 16%more accurate than the pure linear model and the dynamic model.When the input is high frequency signal,the accuracy is about 6.64%higher than the hysteresis model.