基于EWT-FastICA的水下超声回波信号降噪方法研究  

Research on Noise Reduction Method of Underwater Ultrasonic Echo Signal Based on EWT-FastICA

作　　者：安家乐 朱颖 曾庆军[1] AN Jiale;ZHU Ying;ZENG Qingjun(College of Automation,Jiangsu University of Science and Technology,Zhenjiang 212000,China)

机构地区：[1]江苏科技大学自动化学院,江苏镇江212000

出　　处：《软件导刊》2024年第10期112-119,共8页Software Guide

基　　金：国家自然科学基金项目(11574120);江苏省产业前瞻与共性技术项目(BE2018103)。

摘　　要：针对水下超声无损检测易受噪声信号干扰导致缺陷检测精度低的问题,提出基于经验小波变换(EWT)结合快速独立分量分析(FastICA)的水下超声回波信号降噪方法。首先,应用EWT算法对超声回波信号进行分解,得到不同尺度的模态分量(IMF);其次,通过模糊熵(FuzzyEn)算法计算各模态分量模糊熵值,筛选出所需要的模态分量;最后,进行FastICA运算,将筛选出的IMF重构,最终实现超声回波信号与噪声信号的盲源分离,得到纯净的超声回波信号。仿真与实例实验表明,EWT-FastICA结合的降噪方法在超声回波信号降噪处理中,改善了传统经验模态分解出现的模态混叠、端点效应,以及过包络、欠包络等现象,并且降噪处理过程更加快速、准确,可应用于类似的水下超声检测信号降噪处理。Aiming at the problem that underwater ultrasonic non-destructive testing is susceptible to noise signal interference,resulting in low defect detection accuracy,an underwater ultrasonic echo signal detection method based on empirical wavelet transform combined with fast independent component analysis is proposed.First,the EWT algorithm is used to decompose the ultrasonic echo signal to obtain the intrinsic mode function(IMF)of different scales;then the fuzzy entropy value of each modal component is calculated by the fuzzy entropy algorithm,and the required modal components are screened out;finally the FastICA operation is performed to reconstruct the screened IMF,and the blind source separation of the ultrasonic echo signal and the noise signal is realized,and a pure ultrasonic echo signal is obtained in the end.The simulation and experimental examples show that the noise reduction method combined with EWT-FastICA improves the mode mixing,endpoint effect,over-envelope and under-envelope phenomena that occur in traditional empirical mode decomposition,the noise reduction process is faster and more accurate,and can be applied to similar underwater ultrasonic detection signal noise reduction processing.

关 键 词：水下超声无损检测 超声回波信号 模糊熵 EWT FASTICA 

分 类 号：TN911.72[电子电信—通信与信息系统] TB553[电子电信—信息与通信工程]