基于Gabor小波和阈值分析的声发射源定位方法

A Novel Acoustic Emission Source Localization Algorithm Based on Gabor Wavelet Transform and Threshold Analysis

针对声发射信号多模态特性和信噪比低的特点,提出了一种将小波变换和阈值分析相结合的声发射源定位方法。对采集到的声发射信号进行信号频谱分析,提取信号主要频率成分之一的小波变换幅值,得到含有多峰值的时域波形。为消除多峰值的影响,将小波变换最大幅值的80%设为阈值。在时频空间下,确定声发射信号中同一频率下同种模态的波到达传感器的时间差,并测量该模态波在板面传播的群速度,实现声发射源定位。在大理石板上进行声发射两点线定位实验,结果证实该方法的确能提高声发射源定位精度,是一种有效的声发射源定位方法。

A novel AE（acoustic emission） source localization algorithm by combining wavelet transform and threshold analysis together is presented aiming at the features of AE signals＇ multi-modes and low SNR（signal noise ratio）. The signal spectral analysis of the collected acoustic emission signals is carried out to extract the wavelet transforms amplitude which is one of the main frequency components, and the time-domain waveform containing mul- tiple peaks is gotten. 80 % of the maximum amplitude of the wavelet transforms is set as the threshold to eliminate the influence of the multiple peaks. Thus, through getting the time difference of the same wave mode under the same frequency of the AE signal arriving different sensors the time difference of the AE signal arriving different sensors is achieved. After measuring the group velocity of the wave mode, AE source localization is realized. Experiments of the location of AE source between two points on a marble slab are carried out.. Results show that the method is an effective method for locating the AE source and can improve the accuracy of AE source localization.