Study On Control System Of Vacuum Freeze Dehydration Production Line Based On PLC

With the increasing application and development of vacuum freeze dehydration technology, the accuracy and the stability of vacuum freeze dehydration equipment control system requirements is increasingly high. In this paper, according the two requirements, one control method applied to the system of "PLC +PC +Fuzzy" is presented. The control method gather the stability of PLC control, the visual and friendly of PC operation, and the intelligence of Fuzzy together. The control flow of whole equipments how to realize, the communication between PLC and PC, the design of fuzzy controller and the methods how to realize; furthermore, the exploit of PC program by Microsoft Visual C++ are mostly discussed in the paper.The system combines fuzzy control and PLC control in the vacuum freeze dehydration production line, overcomes the difficulty of temperature control, and has advantages control flexible and stability, programming convenient, operation easy and friendly. This kind of system has good performance and applicable value, so it can be used in similar field of industrial control and is a kind of better control strategy.In the course of shading this issue, I completed the following major tasks:1,I lucubrated the characteristics,the functions,the key technologies and the steps of implemention about thec, and summed up the advantages and disadvantages of these existing equipments, and then, based on this, a new control mode of "PLC +PC +Fuzzy" is been proposed.2,I analyzed the fuzzy algorithms, and designed the fuzzy controller.3,cresearched the feasibility of PLC , and selected the CJ1 series OMRON PLC and some modules.4,I detailed analyzed of the production process of the vacuum freeze dehydration equipment, and then Painted flowcharts, Programmed.5,Trial operation in engineering.