压电执行器输出位移的精密自感知  

Precise self-sensing for output displacement of piezoelectric actuator

作　　者：熊志文 崔玉国[1] 蔡永根 马剑强[1] 杨依领 Xiong Zhiwen;Cui Yuguo;Cai Yonggen;Ma Jianqiang;Yang Yiling(The Faculty of Mechanical Engineering and Mechanics,Ningbo University,Ningbo 315211,China)

机构地区：[1]宁波大学机械工程与力学学院,宁波315211

出　　处：《仪器仪表学报》2023年第7期28-36,共9页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(52075273);国家自然科学基金(51175271);宁波市科技创新2025重大专项(2020Z070)资助。

摘　　要：为省掉外部精密位移传感器,进而减小微装配与微操作系统的体积,降低系统成本,采用自感知方法来获取压电执行器的输出位移。首先,基于压电执行器在电压作用下发生变形的同时,还会发生电极化而在其晶片表面产生电荷这一思想,提出了一种非平衡电流积分式压电执行器的位移自感知方法。其次,考虑到压电执行器的漏电流与介电吸收电流,以及运算放大器的偏置电流对自感知精度的影响,给出了能够精确反映压电执行器输出位移的自感知表达式及自感知参数辨识方法。最后,在辨识压电执行器自感知参数的基础上,实验验证了所提精密位移自感知方法的有效性,结果表明,自感知位移具有亚微米级分辨率,为0.24μm;在静态位移自感知方面,在0~118.9μm的位移范围内,自感知位移的最大相对误差为1.17%;在动态位移自感知方面,在0~100 Hz的频率范围内,自感知位移的最大相对误差为1.45%。可知所提出的精密位移自感知方法既能实现静态长时间又能实现动态快速的高精度、高分辨率的位移自感知。To eliminate the external precision displacement sensor,reduce the volume of the micro assembly and micro operation system,and reduce the system cost,the self-sensing method is used to obtain the output displacement of the piezoelectric actuator.Firstly,the deformation of the piezoelectric actuator under the action of voltage is utilized.Meanwhile,the piezoelectric actuator is be polarized and charges on the surface of its surface is generated.A displacement self-sensing method of the unbalanced current integral piezoelectric actuator is proposed.Secondly,considering the influence of the leakage current and dielectric absorption current of the piezoelectric actuator,as well as the bias current of the operational amplifier on the self-sensing accuracy,the self-sensing expression and the self-sensing parameter identification method which can accurately reflect the output displacement of the piezoelectric actuator are given.Finally,on the basis of identifying the self-sensing parameters of the piezoelectric actuator,experiments evaluate the effectiveness of the proposed precision displacement self-sensing method.The results show that the self-sensing displacement has a sub-micron resolution of 0.24μm.In terms of static displacement self-sensing,the maximum relative error of self-sensing displacement is 1.17%in the displacement range of 0~118.9μm.In terms of dynamic displacement self-sensing,the maximum relative error of self-sensing displacement is 1.45%in the frequency range of 0~100 Hz.The proposed precision displacement self-sensing method cannot only realize the static long-time,but also achieve the dynamic fast high-precision and high-resolution displacement self-sensing.

关 键 词：压电执行器 位移自感知 电流积分 电荷补偿 

分 类 号：TH703[机械工程—仪器科学与技术]