基于改进小波域阈值法的平移不变振动信号去噪*

作者：张婷婷，杨洁明 日期：2009-06-24/span> 浏览：3667 查看PDF文档

基于改进小波域阈值法的平移不变振动信号去噪*

张婷婷，杨洁明
（太原理工大学 机械电子研究所，山西 太原 030024）

摘要：针对含噪振动信号的去噪问题，采用了目前最有效的小波算法。在传统小波域阈值法的基础上，克服了软、硬阈值的缺陷，采用了新的阈值函数，并通过平移不变小波变换对去噪效果进行了强化。通过与几种方法去噪效果的仿真对比，其结果表明，新的去噪方案可以获得最大的信噪比（SNR），其去噪效果明显优于传统的软、硬阈值函数，并在实际振动信号的处理中得到了很好的应用。
关键词：小波变换；平移不变；阈值函数；去噪；信噪比
中图分类号：TP206+.3文献标识码：A文章编号：1001-4551(2009)06-0065-03

Translationinvariant denoising of vibration signal based on
improved wavelet domain thresholding method
ZHANG Tingting, YANG Jieming
(Institute of Machanical and Electronic Engineering, Taiyuan University of Technology, Taiyuan 030024, China)
Abstract: In order to denoise the vibration signal including noise, the most effective method of wavelet algorithm was adopted. The flaw of hardandsoftthreshold function was overcome on base of wavelet domain filtering method. The denoising effect in new threshold function was strengthened by cyclespinning. The experiment results show that the new denoising scheme can carry out the best result in signal to noise ratio(SNR) valuation, compared with other known methods. And the scheme also can be used in practice.
Key words: wavelet transform; translationinvariant; threshold function; denoising; signal to noise ratio(SNR)
参考文献(References):
［1］MALLAT S. A wavelet Tour of Signal Processing［M］. 2nd ed. California: Academic Press,1999.
［2］DONOHO D L. Denoising by softthresholding［J］. IEEE Transactions on Information Theory,1995,41(3):613-627.
［3］潘泉,张磊,孟晋丽,等.小波滤波方法及应用［M］.北京：清华大学出版社,2005.
［4］张弦,李世平,孙浚清,等.一种改进的小波阈值去噪方法［J］.微计算机信息,2007,23(11):309-311.
［5］COIFMAN R R, DONOHO D L. Translationinvariant Denoising［M］. SpringerVerlag,1994.
［6］BERKNER K. Smoothness estimates for softthreshold denoising via thranslationinvariant wavelet transforms［J］. Applied and Computational Harmonic Analysis,2002(12):1-24.
［7］陈白.基于小波包变换和小波阈值消噪的语言特征提取［J］.机电工程,2008,25(9):28-30.
［8］胡学友,张林.小波变换在CCD视频图像去噪中的应用［J］.机电工程,2007,24(11):18-20.
［9］任海军，蒋和生.小波分析在摩托车曲轴总成动平衡检测中的应用［J］.机械,2008,35(8):62-65.