小波包原理及其在机械故障诊断中的应用

The Application of Wavelet Packet to Machinery Diagnosis

小波分析是一种日益获得广泛应用的信号处理新技术，它具有良好的时－频局部化特性，因而非常适于分析瞬态或时变信号。利用小波包时机械振动柜号进行分解可以获得信号的时－频分布特性，对于分析以非稳态振动为表征的机械故障提供了有效的分析手段。本文简述了小波和波包的基本概念以及利用小波包对振动信号进行时－频分解的方法。文中给出了利用小波包进行信号处理和故障分析的实例，并与其他诊断方法进行了比较。

Wavelet analysis, as a new technique of signal processing, possesses excellent characteristic of time-frequency localization and is suitable for analysing the time-varying or transient signals. The timi-frequency feature of vibration signal obtained by decomposition via wavelet packet provids an effective measure for analysing the machinery faults causing unstable vibration. In this paper the basic concepts of wavelet and the method of time-frequency decomposition of vibration signals are briefly introduced. Examples of signal processing and machinery fault analysing via wavelet packet, as well as via other methods for comparison, are provided.