PLC Control Of Beer Fermentation Process Based On PROFIBUS Technology

Beer production, as one of the most important traditional industry, has been developed quickly in our country with the development of civil economy and the improvement of standard of living. However, because of the complexity of the beer production, domestic breweries have many disadvantages when compared with breweries in advanced countries, such as outdated measurement and control equipments, low level of automation, instable product quality, etc. How to improve the integrated automation level in beer production becomes an urgent research project. Beer fermentation is one of the key steps of beer production. Thus, on the basis of some projects in breweries, this thesis investigated beer fermentation automation and Fuzzy Intelligent PID algorithm applied in this process. It is an attempt to apply high technology to traditional industry and has importantly practical meaning.Following are the main contributions of this thesis:1. Nowadays many breweries in China still use outdated control systems,which can not satisfy the product need. In recent 10 years , Field-bus technology has been more and more applied in control field. PROFIBUS Field-bus is a communication system which is open and independent of manufacturer and it has been become a standard in German and Europe .Siemens S7-400 PLC constituted data processing and control system in which PROFIBUS-DP process technology are adopted to achieve data exchange and control between PLC main station and I/O slave stations.2. In beer fermentation , temperature is an important parameter that can effect the quality of beer .The process has the characteristics of large inertia ,long time delay and nonlinear ,which is difficult to accurately control following process curve .According to the difficulty of temperature controlling in beer fermentation ,a sort of algorithm of fuzzy intelligent PID control is introduced ,which combines fuzzy control and PID control .It adds fuzzy logistic differential control and intelligent integral control to fuzzy set-point weight turning (FSW).The insufficiency of original PID control method is effectively improved by this way.