摘要
通过对小波消噪原理的分析及常用阈值规则的降噪性能对比,提出了基于小波细节系数自相关性分析的分层阈值降噪法,描述了根据有用信号最小频率成分确定最大分解层数的方法,给出了分层阈值降噪法的步骤,并对模拟的含噪振动信号进行了试验研究,结果表明,该方法具有较好的降噪效果,尤其适合于强噪声背景下弱信号的恢复,有利于较高频率有用信号的提取。最后,对小波分层阈值降噪法在发动机振动信号分析中的实际应用进行了研究,研究证明,该方法可以有效地抑制背景噪声,提取有用状态信息,为发动机振动信号预处理提供了一种切实可行的方法。
The de-noising principle using wavelet was discussed and the de-noising property was compared with that of using general threshold strategy. A per-level de-noising method based on analysis of autocorrelation of wavelet detailed coefficients was proposed. The maximum wavelet decomposing level was determined according to the minimum interest frequency. The steps of the per-level de-noising method were then given and the experimental study with a vibration model was carried out. The results prove that the method is advantageous to de-noising, which is more suitable to recover the interest weak signal buried in intenive background noise. The application of the method in the engine vibration was presented and the results show that it can inhibit the background noise effectively and recover the interest information satisfactorily.
出处
《振动与冲击》
EI
CSCD
北大核心
2009年第8期57-60,共4页
Journal of Vibration and Shock
基金
吉林省教育厅科研计划资助项目(吉教科合字[2004]第17号)
关键词
小波
降噪
阈值
自相关序列
wavelet
de-noising
threshold
autocorrelation sequence
