用于电磁超声检测信号的联合降噪方法  

A combined noise reduction method for electromagnetic ultrasonic detection signals

作　　者：杨斌 易朋兴[1] 郝峥旭 YANG Bin;YI Pengxing;HAO Zhengxu(School of Mechanical Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]华中科技大学机械科学与工程学院,武汉430074

出　　处：《应用声学》2025年第2期519-528,共10页Journal of Applied Acoustics

基　　金：国家自然科学基金项目(2018YFB2003303)。

摘　　要：为自适应地滤除电磁超声检测信号中的低频偏置与高频噪声,降低噪声对后续信号特征分析的影响,提出了一种将变分模态分解与改进阈值的小波变换相结合的二级框架降噪算法。该方法首先使用变分模态分解对信号进行分解并使用评价系数选择合适的模态函数分量对信号进行重构,之后使用改进阈值的小波变换法进行二次滤波。通过对不同噪声水平的仿真信号进行降噪处理,验证了该方法的优越性,在实际缺陷检测信号的降噪处理中也表现出了优异的性能。因此,该方法能够用于电磁超声检测信号的降噪。To filter out the low-frequency bias and high-frequency noise in the electromagnetic ultrasonic de tection signal adaptively,and reduce the influence of noise on the subsequent signal characteristic analysis,a two-level frame noise reduction algorithm combining variational mode decomposition and improved threshold wavelet transform was proposed.In this method,the signal is decomposed by variational mode decomposition,and the signal is reconstructed by selecting the appropriate mode function component with evaluation coeffi cient.Then the wavelet transform method with improved threshold is used for the signal secondary filtering.The superiority of the method is verified by the simulation signal with different noise levels,and the excellent performance is also shown in the real defect detection signal.Therefore,the method can be used to reduce the noise of electromagnetic ultrasonic detection signals.

关 键 词：电磁超声信号 变分模态分解 小波降噪 阈值函数 

分 类 号：TN911.7[电子电信—通信与信息系统]