子波分析及其在机械故障诊断中的应用

Wavelet Analysis and Its Application in Machinery Diagnosis

子波分析是一种日益获得广泛应用的信号处理新技术，具有良好的时－频局部化特性，尤其适用于时变及非平稳信号。本文简述了子波函数与子波展开的基本概念，利用展缩子波和调和子波将信号及信号均方值进行时－频两维分布。最后采用了三种子波分析方法对轴承故障进行诊断，即使对现有各种方法尚难以诊断的滚动体故障，也能获得满意的结果。

Wavelet analysis, as a new technique of signal processing, possesses excellent characteristic of time frequency localization and is suitable for analyzing the time varying or transient signals. In this paper, the basic concepts of wavelet function and wavelet expansion are briefly introduced. The time frequency distribution of signal and its energy are obtained by decomposition via dilating wavelet and harmanic wavelet. Three methods are applied for bearing localized defect detection, based on wavelet transform. Even for roller damaged bearing which is difficult to be detected via existent methods, we can obtain satisfactory results.