基于小波变换的在役管线漏磁信号的去噪  

The De-noising of MFL Signal from the Working Pipes Using Wavelet Transform

作　　者：沈兆鑫[1] 何辅云[1] 

机构地区：[1]合肥工业大学计算机与信息学院,安徽省合肥市230009

出　　处：《电子工程师》2006年第7期41-44,共4页Electronic Engineer

基　　金：国家科技部社会公益基金资助项目(Z00-G03)

摘　　要：采用漏磁法对在役管线进行无损检测时,所采集的信号中含有大量的噪声需要去除。文中介绍了小波变换的基本理论及检测信号和噪声信号在小波变换下的特性,说明了去除漏磁信号噪声的原理。在仿真试验中采用二阶双正交样条小波为小波函数,选用软硬阈值折中法和自适应阈值处理小波系数,结果表明将小波变换应用于在役管线漏磁检测中,能很好地去除噪声,提取出有用信号。When magnetic flux leakage （MFL）appeared in nondestructive test of working pipes, the MFL signal contains a lot of noise that needs to be reduced. This paper introduces the basic theory of wavelet transform and the characteristic of MFL signal and noise under wavelet transform, the principle of MFL signal denoising is also illustrated. In a simulation experiment, a second-order spline wavelet is chosen as wavelet function and a compromised algorithm between soft-thresholding and hard-thresholding and adapting threshold value are adopted for processing wavelet coefficients. The result indicates that noise can be eliminated and the useful signal can be extracted using wavelet transform in MFL of working pipes detecting.

关 键 词：小波变换 去噪 自适应 漏磁 软硬阈值折中法 

分 类 号：TN911.72[电子电信—通信与信息系统]