Weighted envelope spectrum based on reselection mechanism and its application in bearing diagnosis


 As a powerful algorithm, Fast Spectral Correlation (SC) is widely used in bearing fault diagnosis. However, the interference of strong background noise and the existence of multiple fault-related frequency bands make it difficult to realize the bearing fault diagnosis by using enhanced envelope spectrum (EES) and improved envelope spectrum (IES) which are on basis of Fast-SC. To alleviate the problem, Fast Kurtogram (FK) is imitated to divide the spectral frequency bands; then threshold based diagnostic feature (TDF) of each frequency band is calculated to guide the weighting function of corresponding level; finally, WES with the largest TDF is determined as the output, and this process is called the reselection mechanism. Simulation and experimental results indicate that the design of weighting function highlights the contribution of the fault-related frequency bands, and the determination of reselection mechanism further improve its performance.