The Study Of Controller Of Intelligent Electro-Hydraulic Valve Actuator

The intelligent Electro-Hydraulic valve actuator is widely used to operate and regulate valves in the industry control system. The improvement of its stability, precision and the intelligence degree has a great influence on the improvement of the performance of the whole control system.After analyzing the status and developing trend of Electro-Hydraulic valve actuator at home and abroad, the thesis gives the scheme design based on the past successful experience. The research and exploiter are also made from the two ways of hardware and software on the basis of the mature consideration of possible factors affecting system precision.The system adopts closed-loop control mode, and the key controller is P87C552 micro controller. Through comparing the setting signal with the feedback signal, the controller performs the start-up or shut-down of servo motor and controls the aperture of the valve. The system has a feedback function of remote analog signal. A serial communicate interface is designed to make the system adapted to concentrate control. The system adopts control without contact, which has multi functions, such as open circuit protection. And a series of software and hardware protection measures are also adopted, which has more stable and intelligent characteristics than common actuators.Following the principles of safety, reliability, advancement and conveniences, the thesis uses 51-assembler language to program the software used for controlling the system, which accomplish the requirement of functions. Furthermore it's convenient to program and easy to read.