电磁超声系统强噪声干扰抑制算法研究

Research on the De-noising Algorithm of Strong noises in the EMAT System

在采用电磁超声技术(EMAT)进行车轮踏面探伤时,针对检测数据中存在的噪声问题提出一种结合小波算法和相位差算法的综合算法。根据噪声及有用的电磁超声信号的特征,得出小波软阈值去噪方法;结合布莱克曼窗函数及信号的频谱特征,提出一种利用简单三角函数来实现信号相位计算的方法;算法在改善电磁超声系统数据波形质量、提高系统的检测准确性方面具有一定参考作用。

Using the electro-magnetic acoustic transducer（EMAT） for flaw detection represents a new trend of the development of nondestructive testing.An integrated algorithm consisting of the wavelet algorithm and the phase difference algorithm is presented to solve the noise problem existing in the detecting procedure.Based on the features of noises and useful EMAT signal,a wavelet soft-threshold de-noising algorithm is found out.On the basis of the Blackman window and spectrum characteristics of the data,the method that the simple trigonometric function is designed to realize the phase calculation is put forward.This algorithm will improve the waveform quality and raise the detection accuracy of the EMAT system.