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

Table 2

Hurst exponent of the nonlinear vibration signal of the cylinder block.

Hurst exponents	q = −5	q = −3	q = −1	q = 1	q = 3	q = 5
Early phase	1.074	0.974	0.786	0.574	0.441	0.380
Late phase	1.174	1.106	0.998	0.880	0.794	0.744