Nonlinear Vibration Feature Recognition Method for Reciprocating Compressor Cylinder Based on VMD-Multifractal Spectrum

Table 3

Scale index of the nonlinear vibration signal of the cylinder block.

Index of the scales	q = −5	q = −3	q = −1	q = 1	q = 3	q = 5
Early phase	6.373	3.922	1.786	0.425	0.325	0.902
Late phase	6.873	4.320	1.998	0.119	1.382	2.722