An Improved Feature Parameter Extraction Algorithm of Composite Detection Method Based on the Fusion Theory

Table 1

Feature parameter description of PEC and UT response curve.

Label	Parameter	Meaning	Source
1	Peak	The maximum voltage over a period, except for fluctuations at the beginning and end	PEC
2	Peak time	The time it takes to reach the peak (-axis)	PEC
3	Zero-crossing time	The time difference of zero between the first and the second voltage values	PEC
4	Mean value		PEC
5	Mean square error		PEC, UT
6	Pulse index		PEC
7	Crooked degree index		PEC
8	Kurtosis index		PEC, UT
9	Amplitude of fundamental component	The amplitude of the first peak of the response curve in the frequency domain	PEC
10	Amplitude of third harmonic component	The amplitude of the third peak of the response curve in the frequency domain	PEC
11	Defect band mean	The mean ordinate of the bands with significant defect signals in the differential response curve	UT
12	Maximum differential peak	The maximum peak value of the wave caused by the difference between the defect and the nondefect signals in the differential signal	UT
13	Second differential peak	In the differential signal, the second peak value of the wave is caused by the difference between the defect and nondefect signals.	UT