基于PI模型的AFM压电陶瓷执行器迟滞误差补偿

本文针对原子力显微镜（Atomic Force Microscopy，简称AFM）迟滞特性易降低扫描图像精度，根据微位移测量的方法建立了可以精确描述AFM系统中压电陶瓷器执行器（Piezoelectric Ceramic Transducer，简称PZT）迟滞误差模型并提出了合适的误差补偿方法。首先，原子力显微镜作为测量工具，获得一系列特征样品的扫描图像，通过计算扫描图像数据计算出压电陶瓷的微位移。接着，依据微位移数据建立AFM系统中压电陶瓷执行器迟滞误差模型。最后，通过对压电陶瓷PI （Prandtl-Ishlinskii）迟滞误差模型解析求逆进行补偿控制方法研究。实验结果证明，PI迟滞误差模型可以精确描述AFM系统中压电陶瓷执行器的迟滞现象，基于该模型的补偿控制方法可以有效减小迟滞误差，是提高AFM系统中压电陶瓷执行器定位精度的一种有效方法。

Hysteresis Error Compensation of AFM Piezo-ceramic Actuator Based on PI Model

Complex nonlinear hysteresis exists in Atomic force microscopy (AFM),which can lead to the accuracy re-duction of scanned image easily. Hysteresis error model of piezo-ceramic actuator was established accurately in AFM based on micro-displacement measurement method. An appropriate error compensation method is also presented. Firstly, a series of features of the scanned sample image are obtained by AFM as a measurement tool. The micro-displacement of the piezo-ceramic actuator is calculated through the image data. Hysteresis error model of piezo-ceramic actuator is established in AFM system based on the micro-displacement data. Finally, compensation method of hysteresis error is studied by resolving the inverse solution of the PI (Prandtl-Ishlinskii) hysteresis error model. Experimental results show PI model can describe the hysteresis error phenomenon in AFM piezo-ceramic actuator accurately. The compensation control method based on the model can reduce the hysteresis error effectively and improve the positioning accuracy of piezo-ceramic actuator. It’s a kind of effective method to improve the positioning accuracy of piezo-ceramic actuator in AFM system.