摘要
提出基于小波包变换的EMD算法,并将其应用于超声回波信号去噪.对于采用EMD分解含高斯白噪声的超声缺陷信号存在模态混叠的问题,首先用小波包变换对信号作预处理,再对信号进行EMD分解,最后重构出有用的缺陷信号.实验结果表明:该方法不仅具有很好的消噪效果,而且重构的缺陷信号的波形失真度小,有利于对信号做进一步的定量分析.
In this paper, an EMD （Empirical Mode Decomposition） algorithm based on wavelet packet transform is proposed and applied to ultrasonic echo signal de-noising. For the problem of mode mixing caused by the EMD decomposition of ultrasonic flaw signals with Gauss white noise, wavelet packet transform is applied to preprocess ultrasonic echo signal, and followed by EMD decomposition, finally the useful defect signal is reconstructed. The experimental results show that, this method has good de-noising effect with small waveform distortion of reconstruction defect signal. It is conducive to the further quantitative analysis of ultrasonic echo signal.
出处
《南京信息工程大学学报（自然科学版）》
CAS
2012年第5期442-446,共5页
Journal of Nanjing University of Information Science & Technology（Natural Science Edition）
基金
江苏省"六大人才"高峰资助项目(JXQC-139-132)
教育部留学回国人员启动基金(2010609)
关键词
经验模态分解
固有模态函数
小波包
超声信号消噪
empirical mode decomposition
intrinsic mode decomposition
wavelet packet
ultrasonic echo signal de-noising
