Fault Diagnosis of Wheel Flat Using Empirical Mode Decomposition-Hilbert Envelope Spectrum

Table 1

Effects of flat length on Hilbert envelope spectrum amplitude with single flat.

Flat length; (mm)	Actual frequency; (Hz)	Amplitude of IMF1Hilbert envelope spectrum; (m/s^2)	Sum of Hilbert envelope spectrum amplitude of IMF1-IMF3 (m/s^2)
10	9.663	0.2771	0.6241
20	9.663	0.4736	0.8563
30	9.661	0.7822	1.6616
40	9.659	1.1364	2.4500
50	9.659	1.6320	3.4636