基于Gabor时频滤波的电磁超声螺栓轴力测量  

Bolt axial stress detection of electromagnetic ultrasonic signal based on Gabor time-frequency filtering

作　　者：苏杰庆 丁旭 SU Jieqing;DING Xu(Hubei Key Laboratory of Mechanical Transmission and Manufacturing Engineering,Wuhan University of Science and Technology,Wuhan 430081,China;Precision Manufacturing Research Institute,Wuhan University of Science and Technology,Wuhan 430081,China)

机构地区：[1]武汉科技大学机械传动与制造工程湖北省重点实验室,武汉430081 [2]武汉科技大学精密制造研究院,武汉430081

出　　处：《应用声学》2024年第3期584-590,共7页Journal of Applied Acoustics

基　　金：国家重点研发计划项目(2017YFF0210701)。

摘　　要：高强度螺栓轴向预紧力(轴力)的测量在工程应用中具有重要意义。使用电磁超声波对螺栓轴力检测时对超声回波声时测量精度要求较高,传统互相关估计法对超声回波声时估计易因噪声干扰发生估计错误,无法满足轴力测量精度要求。针对互相关法对电磁超声测量信号声时估计存在不准确的问题,提出了Gabor时频滤波法。通过螺栓轴力测量实验采集测量信号,对测量信号进行Gabor变换,在时频域中进行滤波,再对去噪后的信号进行互相关估计测得信号的声时,进而计算出螺栓轴力。实验表明:Gabor时频滤波法能有效地滤除电磁超声信号中的噪声,改善互相关估计的稳定性,提高螺栓轴力测量的准确率。The measurement of axial preload(axial stress of bolt)of high strength bolt is very important in engineering.When electromagnetic ultrasonic is used to detect bolt axial force,the accuracy of ultrasonic echo time of flight measurement is high.The traditional cross-correlation estimation method is prone to error estimation of ultrasonic echo transit time estimation due to noise interference,which cannot meet the requirements of axial force measurement accuracy.In this paper,Gabor time-frequency filtering method is proposed to solve the problem that cross-correlation method is not accurate in estimating the transit time of electromagnetic ultrasonic measurement signal.The measurement signals are collected through the measurement experiment of bolt axial force,the measurement signals are transformed by Gabor,filtered in the time-frequency domain,and then the denoised signals are cross-correlated to estimate the transit time of the measured signals,and then the bolt axial force is calculated.The experimental results show that Gabor time-frequency filtering method can effectively filter the noise in electromagnetic ultrasonic signal,improve the stability of cross-correlation estimation,and improve the accuracy of bolt axial force measurement.

关 键 词：螺栓轴力 互相关 声时 电磁超声信号 GABOR变换 

分 类 号：TB529[理学—物理]