高分辨率压电陶瓷微位移检测电路设计与实现

为提高压电驱动的大口径快摆镜控制精度,采用了电阻式应变传感器(SGS)和基于锁定放大信号调理方法来检测压电执行器微位移,该微位移检测电路包括集成在压电内部的电阻式SGS,前端信号调制放大电路、带通滤波去噪电路、相敏解调电路和低通滤波电路等,最后搭建系统验证并利用小波分解重构的方法对微位移信号进行噪声分析。试验结果表明,该系统检测的压电执行器微位移信号良好,噪声满足实际工程中压电陶瓷(PZT)执行器的24nm位置分辨率的要求。

The Design and Implementation of High-resolution Micro-displacement Detection Circuit of Piezoelectric Ceramic Actuator

The resistance strain gauge sensor(SGS) and the method of signal conditioning based on lock-in amplifying are adopted to monitor the micrometric displacement of piezoelectric actuator in order to improve the control precision of large-aperture fast steering mirror driven by PZT actuator. The micrometric displacement monitoring circuit consists of the resistance strain gauge sensor integrated in the piezoelectric actuator, the sensor front-signal modulation and amplifying circuit, band-pass filtering and de-noising circuit, phase sensitive detection and demodulation circuit and low-pass filter circuit etc. Finally, a system is set up to test the circuit and the noise of the micrometric displacement signal is analyzed with the help of wavelet decomposition and reconstruction. The experimental result shows that the micrometric displacement signal monitored by this system is good and the noise meets the requirement of the PZT location resolution of 24 nm in the actual project.