Simulation And Experiment Research On The Main-stage Velocity Parallel Feedback Control Theory Of The Two-stage Hydraulic Valve With Electrical Feedback

The hydraulic valve, which is one of the key parts of the electro-hydraulic servo control system and the electro-hydraulic proportional control system, its performance often determines the performance of the whole electro-hydraulic control system. The structure of the hydraulic valve, the coupling relation between the internal various physical of the hydraulic valve, and the valve control strategy adopted by the controller would have a major impact on the performance of the hydraulic valve.On the based of summarizing the coupling modes of the hydraulic valve, the theory block diagrames of the coupling modes were given in this paper, and the coupling modes how to effect the performance of the hydraulic were discussed in this paper. It focuses on introducing the two-stage hydraulic valve with electric feedback, and its general model was given in the paper. On the basis of the general model, the main-stage velocity parallel feedback control strategy was advanved, and the transfer function of this control strategy was derived.The two-stage electric-feedback hydraulic valve 4WRLE16EZ-180SJ -3X/G24ETK0-A1/M was taken as the research object in this paper, on the basis of knowing the principle of the hydraulic valve, the transfer functions of all aspects of the hydraulic valve were calculated in details, including the transfer functions of the pilot stage valve, main stage valve and the controller, and so on. According to the main-stage velocity parallel feedback control strategy and the transfer functions been calculated, the mathematical simulation model of the two-stage electric-feedback hydraulic valve system with main-stage velocity parallel feedback control strategy was gained in this paper. By using the software Matlab7.1/SIMULINK, the system model established by this paper was simulated on step response. The analog control system and the digital control system of the two-stage electric-feedback hydraulic valve were designed in this paper, and the main-stage velocity parallel feedback control strategy was achieved through hardware and software respectively.Finally, through experimenting on the analog control system and digital control system of the two-stage electric-feedback hydraulic valve, this paper acquired the static characteristic curves and step response characteristic curves. Simulation and experiment results showed that the main-stage velocity parallel feedback control strategy could improve the performance of the two-stage electric-feedback hydraulic valve by reducing the maximum overshoot of the system effectively and decreasing the setting time and the oscillations time, proving that the main-stage velocity parallel feedback control strategy was correct and feasible.