Microcomputer Electro-hydraulic Proportion Position Control System

At present, the development of hydraulic press are mainly embodied in controlling aspect at home and abroad, the traditional on-off control and the PLC control mode can't satisfy the product accuracy request and the interface personalization demand of the controlling system increasingly. On the base of it , in order to achieve accuracy control purpose, industrial control computer (IPC) is adopted to be composed of the closed loop control system by making use of the peripheral interface equipment (multifunctional industry board) and the various sensors in this system. Electro-hydraulic proportional system is adopted in the system because it combines the merits of the electric and hydraulic, having good controlling capability, big drive ability, and easy to be controlled by computer.So it is significative and valuable to study the applications of microcomputer electro-hydraulic proportion position control system.Electro-hydraulic proportional closed control system is designed firstly based on the working condition characteristic of the presser and the requirement to hydraulic system in this paper, and the dynamic mathematic model of the hydraulic system is built. In addition, the dynamic and the static qualities of the system are analyzed in detail by means of the knowledge of control theory. And then toward to the instability of the system, PID control is adopted to correct the system, and the 0 type system is improved to I type system, not only making the system stable, and having improved the dynamic quality of the system. Besides, the system is simulated on the basis of the Simulink Toolbox of Matlab and the results of simulation prove that the qualities of the system can satisfy with the practical requirement very well.Be to realize the fine man-machine interface, VB is made use of to program as platform and the data administration, by which we can setup and amend technologic parameter handily, save history note, and display displacement curve of piston real time. but VB does not have the ability to visit the I/O interface directly. In this system, Dynamic Link Libraries(DLL) programmed by VC is called in VB to solve the difficulty of input-output interface. In addition, PCI-7484 industry board is adopted as hardware interface to complete data collection and data output and so on in the paper.Finally,we make use of software to realize figure filter to improve the anti-jamming ability of the system.