基于小波包分析的水泵机组振动信号去噪

阐述了小波包的基本原理，介绍了利用小波包给信号去噪的一般工作原理，结合南水北调东线工程某泵站水泵机组的现场振动测试数据，利用小波包理论对被噪声污染的水泵机组的振动测试信号进行去噪分析，从中提取出无污染的振动信号，进一步对机组的故障做出诊断分析．选用db4小波对原始信号进行3层小波包分解，选用启发式SURE阈值，跟据最低层的小波包分解系数和经过量化处理系数，进行小波包重构．结果表明，利用小波包去噪的相关理论，对信号进行去噪处理有效地消除了噪声污染，使消噪后的信号与原始信号保持相似性．

Vibration signal de-noising of pump unit based on wavelet packets transform

The basic theory of wavelet packet and the general principles of signal de-noising by using wavelet packet were introduced.By combining the vibration test data of pump unit in a pump station in the Eastern Line of South-to-North Water Transfer Project,a vibration signal de-nosing was analyzed.In the signal de-noising,the Db4 wavelet with SURE threshold strategy and the 3 decomposition level were chosen.After the coefficient compression and wavelet packets reconstruction,the de-noising signal was obtained.The result indicated that wavelet packet was useful to deal with de-noise signal,and after de-noising the signal was the same as the original signal.This will be good for the further fault analysis of pump unit.