Multi-Scale Hermitian Wavelet Envelope Spectrum Based Bearing Fault Detection

Abstract

Hermitian wavelet is a low-oscillation, complex valued wavelet, which can detect the singularity characteristic of a signal precisely under strong background noise condition. A new method of bearing fault diagnosis based on multi-scale Hermitian wavelet envelope spectrum is proposed. The multi scale Hermitian wavelet envelope spectrum technique combines the advantages of Hermitian wavelet transform, envelope spectrum and three dimensions color map into one integrated technique. The bearing fault vibration signal is firstly decomposed using Hermitian continuous wavelet transform. Then the real and imaginary parts are obtained. In the end, the multi scale Hermitian wavelet envelope spectrum is obtained and the characteristics of the bearing fault can be recognized according to the multi-scale Hermitian wavelet envelope spectrum. The proposed method has been proved by vibration signals obtained from rolling bearing with inner or outer race fault. The experimental results verified the effectiveness of the proposed method.