Design And Simulation Of The Electrohydraulic Servo Valve Testing System

Electrohydraulic servo valve is the crucial component of the electrohydraulic servo system. Its static characteristic and dynamic characteristic have very important meanings while studying in the theory and experiment of the electrohydraulic servo system.The characteristic of electrohydraulic servo valve includes two respects of the stable state characteristic and dynamic characteristic. Main stable state performance has characteristic of flow with loads, unloaded flow characteristic, pressure characteristic and inside leakage characteristic; Main dynamic performance is as follows, frequency response characteristic and steps response characteristic. In addition because servo valve often works in zero areas, so the zero areas characteristic is very important, involving zero excursion and zero float characteristic, zero point threshold value and discernment ratio. The whole design of the test system project is mainly a design systematic in hydraulic system, and then has carried on design components. It is mainly systematic hardware equipments and software compiled in the chapter of the data to be gathered and dealt with. Hardware system finished data gathered and communication task mainly, and hardware include computer, sensors, input-output interface circuit, computer peripheral equipments, etc.... What systematic software design is adopted is module structure, with each module finishing a function confirmed and having relative independence among each module. A low plus closed system of the position to be centered has been added in the dynamic tsting system, which is a displacement sensor is placed in the other end of the cylinder and it is regarded as the detecting element when piston deviates from center. The output signal of the sensor is feed back through the amplifier to the input end of amplifier, as the signal to rectify warp of the cylinder. Detailed analysis was done in the elements of the dynamic state testing system, and the mathematics models of every elements and the displacement-feedback system were founded, and then emulation was carried on based on the models in the MATLAB software. At last the paper drew the conclusion, and prospected in the future.