An Enhanced VMD with the Guidance of Envelope Negentropy Spectrum for Bearing Fault Diagnosis

Figure 26

Results of the experimental signal in Figure 21(a) by different methods: (a) optimal mode extracted by the fixed-parameter VMD and (b) its envelope spectrum; (c) optimal mode extracted by PSO-based VMD and (d) its envelope spectrum.

(a)

(b)

(c)

(d)