A Simultaneous Fault Diagnosis Method Based on Cohesion Evaluation and Improved BP-MLL for Rotating Machinery

Table 1

Cohesion evaluation.

Step	Process parameter	Expression
1	Intracategory standard deviation
2	Average intracategory standard deviation
3	Difference of intracategory standard deviation
4	Distance of each feature
5	Quadratic sum of feature distance
6	Standard deviation of feature distance (intracategory cohesion)
7	Average intercategory cohesion difference
8	Imparity measure of intercategory cohesion difference
9	Cohesion weighting factor
10	Cohesion factor