Intelligent Mechanical Fault Diagnosis Based on Multiwavelet Adaptive Threshold Denoising and MPSO

Table 4

Clustering centers obtained by SPO.

Machinery condition	Clustering centers
	𝑃1	𝑃5	𝑃6
Normal	0.371	2.922	0.069
Outer-race defect	0.583	6.081	0.558
Inner-race defect	0.082	3.825	0.175
Roller element defect	0.579	5.325	0.020