Design And Research Of Two Dimensional(2D) Electro-Hydraulic Pressure Servo Valve And Its Controller Based On LVDT

Electro-hydraulic pressure servo valve is a precision product with high integration of machine,electricity and liquid.At present,there is an increasing demand for its industrial and military fields,but only a few foreign manufacturers have the ability to develop,and poor ability to resist pollution.In order to meet the needs of the military field,a 2D electro-hydraulic pressure servo valve is designed on the basis of 2D digital flow valve.Compared with other structural pressure servo valve,the 2D electro-hydraulic pressure servo valve has simple structure,good stability,strong ability to resist pollution etc.Now,it has been favored by aviation and military fields.In order to obtain high performance electro-hydraulic pressure servo valve,the two-dimensional(2D)electro-hydraulic pressure servo valve and the controller are studied.MATLAB is used to model the pilot valve core,the power level valve core and the electric-mechanical conversion components of the 2D electro-hydraulic pressure servo valve and to analyse the stability of the power level valve core.The current and position double closed-loop PID controller is designed with the PID control strategy and a large number of experimental studies are carried out on the 2D electro-hydraulic pressure servo valve.The main research contents and results are as follows:1.Structure design and improvement of two-dimensional(2D)electro-hydraulic pressure servo valve.The valve sleeve,electric-mechanical conversion element,transmission mechanism and LVDT sensor are designed and improved,and the LVDT sensor is analyzed in depth.2.The mathematical modeling and the working stability analysis of two-dimensional(2D)electro-hydraulic pressure servo valve.The mathematical model of the 2D piston and the single-stage pressure reducing valve is established.The dynamic characteristics of a 2D piston is simulated and the influence factors of dynamic performance of 2D piston is analyzed,and the working stability of the single-stage pressure reducing valve is analyzed,and the squeeze oil film buffer structure is put forward to improve the stability.3.Design of PID controller.The PID control strategy is analyzed,and the PID controller is designed with current and position double closed loop,and the production and debugging of PCB are completed.4.Experimental study of two-dimensional(2D)electro-hydraulic pressure servo valve.In order to verify the correctness of the principle and obtain the static technical index of servo valve,the experimental platform was built and the typical characteristics were studied experimentally.The results show that the hysteresis of the two-dimensional(2D)electro-hydraulic pressure servo valve is 1.26%,and the linearity is 1.86%,and the bandwidth is 70 Hz,with good dynamic and static technical indexes.