Research Of 2D Servo Valve Controller Based On Three-phase Stepping Motor

Electro-hydraulic servo valve is the main component in the electro-hydraulic servo control system,it will enter the tiny electrical signals into high power hydraulic signal(pressure and flow),plays a central role in the whole hydraulic servo system.Electro-hydraulic servo valve is widely used because of the advantages of fast dynamic response,high precision and high power weight.The 2D servo valve consists of a servo spiral mechanism consisting of a sensitive cavity,a high pressure hole and a spiral groove.The rotary motion of the valve core is converted into the axial displacement of the valve core to achieve power amplification.This unique combination of pilot control and power class has the characteristics of small volume,high pollution resistance and fast dynamic response.2 d in addition to the performance of the servo valve and its structure,to a large extent also depends on the electro mechanical converter,therefore,this thesis with three-phase stepper motor as the electro mechanical converter,the study and its controller.With TMS320F2812 of TI company and IRF64N three-phase bridge type of drive circuit for core controller design,overcome the early integrated driver chip limits on current,improve the driving moment of the electro mechanical converter as well as the response speed;Using space vector pulse width modulation technology(SVPWM)and three closed loop current,speed and position control algorithm,to solve the contradiction between the response speed and control precision,realized based on three-phase stepper motor rotor angular displacement in any location quickly and accurately positioning.Specific research contents and results are as follows:1.Study the structure and working principle of 2D servo valve,and conduct mathematical modeling and theoretical analysis.Through MATLAB software simulation analysis of the mathematical model is necessary,studies the influence of 2 d servo valve dynamic and static characteristics of the main factors,in order to realize the 2 d provide theoretical instructions for the design of the servo valve control scheme.2.The 2 d servo valve electrical and mechanical converter(three-phase stepper motor),established the mathematical model and Simulink simulation model,and carried on the simulation analysis,for the electrical and mechanical control technology of converter and the design of circuit board laid a theoretical foundation.3.based on SVPWM technology and id = 0 vector control method,the mathematical derivation and simulation modeling,according to the result of simulation,and injected current of three-phase motor rotor position,position and speed closed-loop control algorithm.The simulation results show that the amplitude attenuation at 420 hz-3 db,at 390 hz 90 °phase lag,it is concluded that the phase lag have bigger influence on the bandwidth.The rise time of the step response is 5.5 ms,the steady state error is almost no,the overshoot is small,and there is no oscillation.A 2D servo valve controller is designed to control the rotor position of three-phase stepping motor.4.The designed controller based on dynamic and static experiments,the experimental results show that compared with the early design collaborative integrated controller,corresponding to 90°,-3 db frequency from 110 hz to 210 hz,the step response of up to 7 ms,show that electrical and mechanical converter has good static and dynamic performance,and also illustrates the rationality of the design of the controller.The experimental platform of 2D servo valve was set up,and the time of the test of the no-load flow rate was 15ms,the bandwidth was about 150Hz,the steady state error was almost no,and the overshoot was small(about 7%).It shows that the 2D digital valve has high response speed and good stability,and has good control accuracy and response speed.