Design Of Temperature Fuzzy Control System Of Central Air-condtioning Based On Distributing Control

DCS(Distributing Control System) is a system based on muliti-microprocessor, used modern network technique, modern control technique, graphics displaying technique, to implement adjusting and monitoring for distributing control systems. DCS have advantages of function distributed and failure distributed, it is fit for the situation when the upper computer manages and monitors multi-lower compuers, the thesis used DCS technique in central air-condition, designed a temperature fuzzy control system of air-conditioning.The thesis brings forward the overall project. The upper-end computer in control station implements the centralized management and control to air fans in air-conditioning room and pumps in fields. Many lower-end computers are distributed in fields and implemented distributing control. The upper-computer and many lower-end computers are connected by controller area network (CAN) to realize information exchange.Because of the big inertia and the hysteresis characteristics of tempeture, the thesis designs a fuzzy control strategy, the strategy is based on expert and the experienced worker, so the system is an intelligent adjusted system. Fuzzy control realize by inquiring about fuzzy rule table. It can be perfect as growing of experence and knowledge of people.Based on the overall project, the thesis designs lower-end computer nodes including switched relactance motor(SRM) nodes and single collecting nodes. The main task design two control methods of SRM, on the spot or long-distance, A/D and D/A conversion circuits, analog voltage collecting circuits, temperature sensor and its adjusting circuits, hardwares and softwares of CAN and compiling and adjusting of the main programs between lower-end computers nodes and upper-end computer nodes.Finishing these tasks mentioned above, we adopt two ways to experiment, temperature open loop and closed loop. At last, summing-up is made on operating performance. The research of the temperature control system of air-conditioning based on distributing control has certain reference value to the next step.