Research On Embedded Intelligent Electro-hydraulic Proportional Valve Controller

Electro-hydraulic proportional control technology, which fully integrate the technologies of hydraulic and electrical control, is a new branch of the area of fluid power transmission and control, has developed into the important means of industrial machinery, engineering construction machinery and products of national defense. As an important component of electro-hydraulic proportional control system, the electro-hydraulic proportional valve controller is a device that providing a specific current to proportional valve, so that the flow or pressure of the liquid under continuously control in proportion to it. With the development of embedded system technology, embedded system is applied to modern industrial control, has brought a new technological revolution. At present, the embedded system has play an irreplaceable role in PC technology, network technology, communication, consumer electronic, industrial control, transportation, aerospace, national defense and so on. Therefore, using embedded system technology to develop the electro-hydraulic proportional valve controller, achieving its intelligent,digital,network is the trend.Based on the detail analysis of the working principle and control principle of the electro-hydraulic proportional valve, this paper design and develop a electro-hydraulic proportional valve controller using embedded system technology, concretely discuss the process and methods of its realization and expound its system structure and basic principle, including the composition and construction methods of embedded system, the PWM driving principle of electro-hydraulic proportional valve, the control theory of displacement closed-loop control, the communication theory base on RS485 and Modbus communication protocol.The control logic and control strategy of this controller is achieved by application software. This controller possesses a simplified structure, high quality and an economical and flexible performance. It can achieve modern complex control strategies easily, such as digital PID, fuzzy control, adaptive control, etc. And it also has the following advantages: parameters can be stored and set repeatedly by PC or bus, the sensitive or critical parameters can be password-protected, it can provide special control functions according to the special requirements of users, such as special control curve, hysteresis compensation and fixed operating mode.Base on embedded system technology solution, the electro-hydraulic proportional valve controller has excellent flexibility and reliability, high performance price ratio, powerful function, promoting the renewal of proportional valve controller product effectively, providing a high-performance proportional valve controller to industrial users.