Background: Single-channel observed signal analysis based on independent component analysis
(ICA) model belongs to the extremely underdetermined blind source separation (BBS) problem.
Method: In order to extract the fault feature hidden in the single-channel measured signal from multi-stage
gearbox, a joint approach of fault feature extraction based on ensemble empirical mode decomposition (EEMD)
and constrained independent component analysis (CICA) is proposed. The single-channel vibration fault signal
is decomposed into several intrinsic mode functions (IMFs) by EEMD, which can overcome the shortcomings
of classical empirical mode decomposition (EMD). By computing the kurtosis and correlation coefficients of
each IMF, we can select some suitable IMFs to construct a newly observed vector combined with the original
signal, which meets the requirement of CICA algorithm. Finally, the suitable reference signal including faulty
gear meshing frequency is generated, and the desired gear low frequency slight feature is extracted by CICA
combined with envelope analysis.
Conclusion: Through the experiment analysis of fault feature extraction with a missing tooth on the low
speed gear pairs, the effectiveness and applicability of the proposed method are verified.