A Novel MPE-LPP-ELM Recognition Method for the Fault Diagnosis of Spiral Bevel Gears

Figure 11

The 3D map at speed of 1,500 r/min. (a) The 3D map of MPE-LPP. (b) The 3D map of MPE-PCA. (c) The 3D map of MPE.

(a)

(b)

(c)