Feature Clustering Analysis Using Reference Model towards Rolling Bearing Performance Degradation Assessment

Table 2

The feature clustering indicator for the monitor dataset at different runtime moments.

Runtime moment	100	300	500	680	740	780	860	920	980
Sb	5.77	7.30	8.51	10.9	12.0	12.5	16.2	18.4	19.3
Sw	4.59	4.51	4.45	4.33	4.27	4.25	4.06	3.96	3.91
SS	1.26	1.62	1.91	2.53	2.81	2.95	3.99	4.65	4.93