基于Duhem模型和逆模型的压电执行器精密定位及控制

为提高压电执行器的定位精度, 研究了压电执行器的Duhem模型及逆模型, 并对传统的Duhem模型进行改进, 将原有的模型分为上下2个半环, 分别进行建模. 然后采用样条曲线插值和神经网络对Duhem模型参数进行辨识, 利用辨识结果建立压电执行器的Duhem模型及逆模型, 并利用PI逆模型作为PID反馈控制的前馈环节进行复合控制, 提高压电执行器的定位精度. 结果表明: 该模型在变幅三角波电压下的输出绝对平均误差为0.0810μm, 复合控制下的输出绝对平均误差为0.0539μm, 能有效地提高压电执行器的定位精度.

ccurate positioning and control of piezoelectric actuator based on Duhem model and inverse model

In order to improve the positioning accuracy of the piezoelectric actuators, the Duhem model and the inverse model of piezoelectric actuators are investigated and improved. The original model is divided into two half-rings, which are modeled individually. By using the spline interpolation and neural network to identify the Duhem model parameters, the Duhem model and inverse model of piezoelectric actuators are established. Furthermore, by using PI inverse model as a feed forward segment of PID feed-back control, a composite control is implemented to improve the positioning accuracy of piezoelectric actuators. Experimental results indicate that the average error is 0.0810μm and the absolute error is 0.0539μm under the composite control, hence it effectively improves the positioning accuracy of the piezoelectric actuator