EMD-循环域解调方法在故障诊断中的应用

THE APPLICATION OF THE EMD-CYCLIC DOMAIN DEMODULATION IN MECHANICAL FAULT DIAGNOSIS

多调制源、多载波信号的循环自相关解调分析存在交叉项的干扰,这使循环自相关解调方法的实际应用产生了困难。在对循环自相关解调及其性能分析的基础上,提出了基于经验模式分解的分频带循环自相关解调方法。该方法通过对信号经验模式分解后能量相对集中的基本模式分量进行循环自相关解调,有效地抑制了多调制源、多载波对循环平稳结果带来的交叉项干扰,提高了分析的可靠性。将该方法应用于滚动轴承的故障诊断,成功地从振动信号中分离出故障源。

The cross-term interference caused by multi-modulator and multi-carrier makes it difficult the use of the cyclic autocorrelation demodulation.Aiming at the problem,a new method called the EMD(empirical mode decomposition)-cyclic domain demodulation is proposed.By demodulating the intrinsic mode function which has the concentrated energy correspondingly with cyclic autocorrelation arithmetic,the new method can decrease the cross-term interference caused by multi-modulator and multi-carrier and improve the reliability of the analysis.As the application of the EMD-cyclic domain demodulation theory in fault diagnosis,the method is used to successfully extract fault feature from vibration signals of rolling element bearing.