Abstract:The liquid solenoid valve is the key control component of the variable displacement piston pump system in aviation. Accurate diagnosis of the fault type of the solenoid valve is an important guarantee for the safe operation of the system; In order to detect and diagnose the solenoid valve in the aviation variable displacement piston pump system, a method based on wavelet energy entropy and neighborhood rough set is proposed; The current fault characteristics of liquid solenoid valve driver are studied; The AMEsim multidisciplinary simulation software is used to establish the simulation model, analyze the relationship between the drive end current and the valve body displacement, build an experimental system, collect the current signals in normal and fault states, and analyze the current characteristics in different states; Then the wavelet packet decomposition is used to reconstruct the signal, and the corresponding band energy is extracted as the feature vector; Finally, variable precision fuzzy neighborhood rough set reduction algorithm is introduced to simplify the numerical attributes, which improves the efficiency of the system; The simplified attribute set is used to build the decision tree. After iterative training, the diagnostic accuracy of the model reaches 90%, achieving the desired effect, and realizing the rapid diagnosis of the liquid solenoid valve.