Compound Fault Diagnosis Based on Dual-tree Complex Wavelet Packet Transform and AR Spectrum for Rolling Bearings

Aimed at separating fault information from compound rolling bearing fault signal,a fault diagnosis method was proposed based on dual-tree complex wavelet packet transform and auto-regressive(AR) spectrum. First,the non-stationary and complex signal of compound fault was decomposed into several different frequency band components through dual-tree complex wavelet packet decomposition. Second,Hilbert envelope was formed from the component that contains the fault information. Finally,the power spectrum was obtained by AR spectrum. Thus,the information of fault feature was separated and identified. Experiments results show that the fault feature of rolling bearing can be separated effectively, and the feasibility and effectiveness of the method are verified.