基于应力波反射的磁致伸缩位移传感器测量方法及信号分析

摘要

在传统磁致伸缩位移传感器结构基础上,提出一种基于应力波无阻尼反射的位移测量方法,该方法可避免磁敏伸缩位移传感器传统测量方法需要位移标定问题,并使位移分辨率提高1倍,制作了样机,通过实验验证了此测量方法的有效性和正确性.文中针对信号傅里叶变换后没有时间和频率之间的定位信息,提出一种基于HHT的回波信号分析和数字滤波方法,使回波信号的信噪比由12.4 dB提高到23.5 dB.%On the basis of conventional structure of magnetostrictive displacement sensor,a new method for measuring the displacement based on stress wave undamped?reflection was proposed,which can avoid the shortcoming that traditional measure?ment method need to be calibrated. The resolution increased by one time. The prototype of magnetostrictive displacement sensor was manufactured.Experiments show the effectiveness and accuracy of this measurement method.Fourier transform lacks of infor?mation between time and frequency.A method to analyze and filter echo signal based on Hilbert Huang transform was proposed. The SNR of the echo signal increases from 12.4 dB to 23.5 dB.