Fe-Ga波导丝的磁致伸缩位移传感器结构设计

摘要

The structure of a Fe-Ga magnetostrictive displacement sensor must be appropriately designed to reduce the impact of driving pulse current and remanence on the detecting signal of a magnetostrictive displacement sensor and further improve its measurement accuracy.Accordingly, this study proposes a magnetostrictive displacement sensor adopting a moving coil.In the design,the permanent magnet is fixed on the head of a waveguide wire,and the position coil can move on the waveguide wire to change the displacement.The prototype of the novel magnetos-trictive displacement sensor based on a galfenol wire is manufactured.The experimental results show that compared with that of the traditional structure,the signal-to-noise ratio of the detecting signal clearly increased from 13.4 dB to 25.2 dB;the maximum amplitude of the detecting voltage increased from 53 mv to 80 mv;and the new structure could achieve the echo rate correction.The moving coil type of the magnetostrictive displacement sensor can effec-tively improve the linearity,repeatability,and hysteresis of the sensor.%为减小剩磁和驱动脉冲电流对磁致伸缩位移传感器检测信号的影响,进而提高传感器的测量精度,对Fe-Ga磁致伸缩位移传感器的结构进行设计,提出了一种移动线圈式结构的磁致伸缩位移传感器,此时永磁体固定在波导丝头部,位置线圈在波导丝上移动起到位移改变的作用.制作了新结构的传感器样机,实验结果表明:与传统结构相比,结构改进后检测信号的信噪比由13.4 dB提高至25.2 dB,检测电压幅值由52 mV提高至80 mV,且能实现回波速度校正.移动线圈式磁致伸缩位移传感器能有效改善传感器的线性度、重复性和迟滞性.