Gearbox Fault Diagnosis Using Complementary Ensemble Empirical Mode Decomposition and Permutation Entropy

Table 1

Correlation coefficients between filtered signals and each IMF.

	Correlation coefficient
	IMF 1	IMF 2	IMF 3	IMF 4	IMF 5	IMF 6	IMF 7	IMF 8	IMF 9	IMF 10
Normal condition	0.5235	0.7648	0.4783	0.4284	0.4036	0.1092	0.0971
Light fault condition	0.8594	0.4635	0.3582	0.2347	0.1921	0.0925
Severe fault condition	0.9219	0.2578	0.2215	0.1937	0.1625	0.0859		0.0008		0.0007