The Study Of The New Controller For Large Flow 2D Servo Valve

With high control precision, large power density, load stiffness and the advantages of quick dynamic response, electric-hydraulic servo system has been widely used in industry, such as machine tools, ships, mines and aerospace. Servo valve is the core component of electric-hydraulic servo system,which can transform the small power electrical signal to high power signal output flow and pressure. The performance of the servo valve largely determines the performance of the electric-hydraulic servo system.This article object of study for a big flow 2D servo valve and 2D servo valve new type of controller. Large flow 2D servo valve use servo screw mechanism in a single rotation of the valve core, valve core movement into a valve core axial movement so as to realize hydraulic power amplifier, the control and the main valve core in a single valve core, this unique structure makes the big flow of 2D servo valve has simple structure, volume and weight is far less than the traditional high flow electric-hydraulic servo valve (usually triple valve); Large flow 2D servo valve with high and low pressure holes on the valve core and valve set of the spiral groove on the hydraulic damping bridge circuit realization control, flow size, strong ability to resist pollution. Large flow 2D servo valve with three-phase hybrid stepping motor as an electric-mechanical converter, not only the advantages of fast response speed, low cost, and easy to realize the direct digital control; At the same time use DSP chip TMS320F2812 and DRV8432 motor driver chip as the core components to design controller, not only has good dynamic and static performance, and make the controller integration, miniaturization, high reliability. Specific research contents and results are as follows:1.This paper investigates the working principle of the 2D digital servo valve, and mechanism design. Established the large flow of 2D digital servo valve mathematical model. And thus established the Simulink model of 2D servo valve, beside that carried on the simulation analysis to study the mainly structure parameters on the dynamic and static characteristics influence of the large flow of 2D servo valve2.Analyzed the structure of electrical-mechanical converter of the 2D servo valve. Established the mathematical model and Simulink model of electrical-mechanical converter., which laid the foundation for Simulink simulation model of the electric-mechanical converter control simulation.3.Put forward using the algorithm of maximum torque and space voltage vector modulation (SVPWM) control method to control the current, rotor position,speed of the motor for three closed-loop control. Realised the electric-mechanical converter in any position to be able to quickly without step out precise positioning. According to above control method, designed the electric-mechanical converter mathematical three closed loop control model, and has carried on the Simulink simulation. The simulation results show that this control method for electric-mechanical converter control system has good dynamic and static characteristics, corresponding to -90°and -3 dB the bandwidth is about 150 Hz, the rise time of the step response is about 12 ms.4.Used the maximum torque control method and the space voltage vector modulation (SVPWM) algorithm, designed the new controller for large flow 2D servo valve,which based on the high speed TMS320F2812 chip and DRV8432 drive chip. Developed a complete set of control program and experimented the dynamic and static of the large flow 2D servo valve.The simulation results show that the new controller for the large flow 2D servo valve control characteristic is good, the repeat precision is less than 3% and linearity less than 1.5%, corresponding to 90° and-3 dB the bandwidth is about 120 Hz, the rise time of the step response is about 15 ms.5.Built the large flow of 2D servo valve performance testing experiment platform, tested the large flow of 2D servo valve no-load and flow characteristic curve and zero leakage characteristics.The experimental results reveal that the large flow of 2D servo valve has good performance. Its frequency width is about 100Hz approximately at -3dB and-90°, rising time of step response is only about 17ms, the overshoot of maximum percentage is about 8%. Which illustrate the usefulness of large flow of 2D servo valve controller.