基于小波包变换的轴承外圈超声检测信号处理研究

摘要

为进一步提高铁路货车轴承外圈超声检测质量，将小波包变换理论应用于轴承外圈超声检测信号处理，构建水浸探伤特征扫描成像系统，将铁路货车轴承外圈应用于水浸探伤特征扫描系统中，对水浸系统采集到的轴承外圈超声信号进行小波包变换，用于缺陷信号的降噪处理，提高超声信号的信噪比。并以小波包分解频带的能量作为缺陷信号特征值，根据小波包不同空间能量谱中能量的大小及分布判断轴承外圈内部缺陷程度。%In order to improve the quality of the UT for railway freight car bearing outer ring , wavelet package transform meth-od was used to process the ultrasonic signals .Immersion testing system for feature scan image was constructed to acquire the echo in ultrasonic testing and the railway freight car bearing outer ring was used in this system .The signals were then filtered using wavelet package transform method to improve the signal -noise ratio , then the energy of the frequency domain based on wavelet packet decomposition was taken as the feature information of defects .And the amount and the distribution of the energy in different wavelet package energy spectrum spaces indicates the defect level in the bearing outer ring .