The Design And Research Of Electro-hydraulic Pressure Servo-controls For42MPa Pulse Test Stand

With the improvement of hydraulic system reliability requirements, pipes andaccessories pressure and shock resistance performance of hydraulic system in automotiveengineering machinery become important indicators. Pressure pulse test stand is aprofessional experiment equipment which makes test equipments produce specificpressure wave according to test requirements. This paper designs a42MPaeletro-hydraulic servo pressure pulse test stand for HB6133and GB/T7939teststandards.The main work of this paper as follows:Firstly, this paper designs the hydraulic system principle diagram of this testingmachine on the basis of pulse test and machine type. According to the testing tasks, thispaper carries on the calculation of the hydraulic system, and designs the mechanicalstructure for the test stand.Secondly, the mathematical model of the test stand was established, based on thepressure servo system of symmetrical servo valve controlled asymmetrical hydrauliccylinder. This paper deduces and simplifies the transfer function of the valve controlledasymmetrical hydraulic cylinder pressure servo system, using the mechanism modelingmethod and according to the basic equations. Then, this paper builts the simulation modelin MATLAB/Simulink, and simulates the different types of input signal.Thirdly, according to testing machine’s periodic testing tasks and easy changecharacteristics of nonlinear electro-hydraulic servo system under different workingconditions, this paper tries to adopt repetitive control and combined control strategy ofPID control, the repetitive controller is designed, and simulated in Simulink, thesimulation results show that this control method can improve the tracking accuracy androbustness of the system.Finally, this paper designs the measurement and control system based on virtualinstrument and PLC control system, installs and debugs the pulse test stand. The actualtest results reaches the requirements of the relevant testing standards, which verifies the correctness of the theory of system modeling, comparing with simulation results of valvecontrolled asymmetric cylinder pressure servo control system model.