Degradation State Identification of Cracked Ultrasonic Motor by Means of Fault Feature Extraction Method

Table 1

RMS statistics of MMS components.

	Layer 1	Layer 2	Layer 3	Layer 4	Layer 5
Normal state	3.27 V	5.36 V	6.29 V	5.19 V	1.52 V
Slight degradation	2.30 V	4.21 V	4.92 V	4.02 V	1.35 V
Severe degradation	1.43 V	2.05 V	2.36 V	2.02 V	0.67 V
Failure state	0.43 V	0.34 V	0.93 V	0.02 V	0.30 V