| Electro-hydraulic servo valves are widely used in aerospace,metallurgy,shipbuilding and other industrial fields due to their excellent performance and control accuracy.With the development of technology in various industries,higher demands have been placed on servo valves.Due to the high purchasing value of servo valves,the economic value of maintenance is enormous.Troubleshooting is at the heart of the maintenance process.However,specialized servo valve fault diagnosis equipment for maintenance purposes is currently in a wide range of conditions.Based on this,this paper proposes a fault diagnosis solution for servo valve based on fault feature matching: the servo valve fault feature database is constructed by the simulation and test data,the portable servo valve test system is used as the fault feature collection terminal,the neural network algorithm is used to realize fault feature matching,complete the operation parameters and fault diagnosis of the remotely collected servo valve across the space.This paper mainly studies the establishment of the servo valve fault feature database and the scheme design of the fault information collection terminal.Through theoretical analysis,fault simulation and experimental research on two kinds of structure servo valves,the fault characteristics of servo valve are obtained,which lays a foundation for establishing an open fault sample database.This paper also proposes an overall engineering solution for automatic detection of portable servo valve performance as a servo valve fault diagnosis data acquisition terminal.In order to provide theoretical guidance and create economic benefits for the maintenance and design of servo valves.Firstly,The establishment of two types of servo valve simulation models,spray-type and direct-drive.By analyzing the working principle and structural characteristics of the two servo valves in detail,the transfer function of each component of the servo valve is established by the mechanism method.Based on this,the simulation model of the whole valve is built by AMESim.It lays a theoretical foundation for the subsequent fault simulation of the servo valve.Secondly,Simulation of servo valve characteristics and typical faults.First,run the simulation model to obtain the influence of its key parameters on the static and dynamic performance of the servo valve;Then,through the simulation analysis of three typical faults such as plugging,wear and mechanical parts defects of the servo valve,the theoretical sample curve of the fault feature is obtained.Next,Portable servo valve performance test system design.Firstly,according to the servo valve test national standard and engineering practice,the functional requirements of the testsystem and the overall design scheme of electro-hydraulic control are determined;Secondly,detailed design schemes such as component calculation and equipment layout are completed.Finally,by analyzing the overall scheme of the test software,the software scheme of the upper and lower machine software and the software scheme of the test system are given.Finally,Experimental study of servo valve testing and fault diagnosis.First,complete the measurement accuracy test of the servo valve test system and verify the system accuracy requirements;Secondly,the performance test of the spray valve and the direct drive valve is carried out to verify the correctness of the simulation model,and the test sample curve of the fault feature is provided for the servo valve fault characteristic database;Finally,based on a large number of experimental foundations,verify the correctness of the fault simulation,summarize the performance patterns and fault causes of common faults of the servo valve,and establish a servo valve fault feature database. |
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