The Research And Design Of The Control About Hydraulic Valve System

Valve is a primary manipulative component on transfers about liquid or gas, and used widely in industry. The fashion of valve driven have four kinds, and they are drive using hands , electrical , hydraulic and pneumatic equipment. The hydraulic drive is used commonly on valve with big caliber and simple tuning characteristic because of its simple frame, weight light, great deferent power comparatively.The growing genes of control field on industry are aptitude and exactitude. The traditional manual control of valve isn't content in some places due to cursory measure and slow reaction, not intelligent too. The development of computer and control technique makes it possible to produce an excellent plan to solve that. This article provides a whole project on control of systems with dispersive structure, aiming at the problem in PSA system that valve in this system must accomplish some action ensuring system's function, and complete the design of system's segments and correlative analysis.This control system is distributed with two grades about structure. First grade is field cell based on SCM (Single Chip Microcomputer), and sampling pressure signal in pipeline and output digital control signal processed by controller, at the same time, system's control function comes true by the digital signal directly acting on the step electrical set in the digital simplified direction valve, which in the hydraulic circuit converts the electric signal to mechanical action-, The second grade is remote control cell in which industrial-control computer with high performance is used to complete monitor function for field cell, and due to its favorable man-machine conversationinterface, operator only need to input information and monitor estate of field simply. The control of field cell is adjusting pressure in the pipeline based on beforehand input value through remote cell. The field controller simples the pressure in the pipeline circularly and compares it with enactment's one, and output control signal by some arithmetic program and drive digital valve till the two values are equality. This is a control circuit in the field cell, and fuzzy control technique is applied in it. Fuzzy control system has some merits: not need mathematics model of controlled system; easily control for system with non-linearity factor; possessing stronger tolerance for the change of parameter of system's identity; possessing stronger restrain capability for disturb on system. According as the characteristic of system designed in the paper, referencing correlation datum, the author brings forward a fuzzy control formulae fitting this system, and makes a simple regulation table deposited in the controller with program form, which can save time and controller's storage space when system run. For the sake of better control effect with brainpower and personification, the simple fuzzy controller is equiped with adaptive mechanism.The system's two distributed grades complete communion of information by CAN (control area net), and the require of brainpower and personification on control systems make the current out markedly which distributed control systems are replacing by field-bus control systems. The field-bus of CAN was studied and brown forward originally by BOSCH of Germany, used on transmit of control signal in car, now, being one of the most prevalent field-bus it is being used widely in many domains. In this paper, CAN is designed in the control system for industry valve, communication modules is projected and consultative of communications being made, the signal transmitting between the two cells is timely, reliable and safe.