An Improved Time-Frequency Analysis Method for Instantaneous Frequency Estimation of Rolling Bearing

Table 4

The kurtosis values and mutual information (MI) of IMFs for real signal with fluctuated speed.

IMF	IMF1	IMF2	IMF3	IMF4	IMF5	IMF6
Kurtosis	4.58	4.93	4.12	2.93	2.26	2.69
MI	0.905	0.986	0.725	0.086	0.048	0.067