The Electro-hydraulic Proportional Valve Control System Research Based Pid Algorithm

Conventional electro-hydraulic proportional valve technology is the technology of the switching valve, proportional valve technology and servo valve technology, which is an analog control technology, its precise control is built on the basis of closed-loop control, it relies on a variety of sensors, servo valve, servo amplifier, controller and other hardware with a variety of automatic control theory combining to complete. This is a system that is very complex, expensive, maintenance is trouble and have high failure rate. It must be designed and debugged by experts, and the experts to use and maintain it.So it is hard to large-scale application.This article describes some strengths and weaknesses of the traditional electro-hydraulic proportional valve technology, and simple analysis of several commonly used electro-hydraulic proportional valve, and described the current situation and development of the proportional valve.The electro-hydraulic proportional valve closed-loop control system of this study is based on PID algorithm,which is a system that some software control instead of some complexity hardware. The system can effectively solve the problems of the conventional proportional valve technology, and its control is a powerful, maintenance low cost, high precision system control and system structure is relatively simple.At electro-hydraulic proportional valve control circuit design, MCU control system, digital PID algorithms and PWM (Pulse Width Modulation) technology are as the object of study. Prepared according to the electro-hydraulic proportional valve control, system control program, design a circuit and power amplifier circuit of the control system, that greatly improve the accuracy and reliability of the control circuit.In this system, the MCU serial communication module connected with the the host computer software, through the PC the system’s operating status can be monitored in real-time,and the operation status of the system can be changed through the PC, so it can achieve human-computer interaction. Accoding to system’s control requirements, in this article established a mathematical model of this control system, obtained the transfer function of the system.And then simulation in MATLAB-SIMULINK environment obtained steady-state and dynamic response characteristics curve of the valve, so as to further optimize the electro-hydraulic proportional valve control system to provide a theoretical basis. To raising the level of electro-hydraulic proportional valve control, and promote the development of modern, digital has a certain practical significance.