| Sifting process of EMD and its application in rolling element bearing fault diagnosis Hongbo Dong
The Journal of Mechanical Science and Technology, vol. 23, no. 8, pp.2000-2007, 2009
Abstract : Among the vibration-based fault diagnosis methods for rolling element bearing, the shock pulse method (SPM)
combined with the demodulation method is a useful quantitative technique for estimating bearing running state. However,
direct demodulation often misestimates the shock value of characteristic defect frequency. To overcome this disadvantage,
the vibration signal should be decomposed before demodulation. Empirical mode decomposition (EMD)
can be an alternative for preprocess bearing fault signals. However, the trouble with this method’s application is that it
is time-consuming. Therefore, a novel method that can improve the sifting process’s efficiency is proposed, in which
only one time of cubic spline fitting is required in each sifting process. As a consequence, the time for EMD analysis
can be evidently shortened and the decomposition results simultaneously maintained at a high precision. Simulations
and experiments verify that the improved EMD method, combined with SPM and demodulation analysis, is efficient
and accurate and can be effectively applied in engineering practice.
Keyword :
Sifting process; EMD; Demodulation; Shock pulse method; Bearing fault diagnosis
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