A Condition Monitoring Method of Hydraulic Gear Pumps Based on Multilevel Mechanism-Data Fusion

Table 1

Time-domain features.

Feature	Equation	Feature	Equation
Maximum value		Root mean square
Minimum value		Square mean root
Peak value		Crest factor
Peak to peak		Pulse factor
Mean value		Margin factor
Mean absolute value		Waveform factor
Variance		Kurtosis factor
Standard deviation		Skewness factor