Greenhouse-based Expert System, Intelligent Control Study

Chinese agriculture is in the new stage transforming from the traditional agriculture toward the establishment agriculture , in this period, the nation has adopted a series of measures to strongly push into the agriculture modernization. The establishment agriculture is an important marking of modern agriculture, the modern greenhouse is one of the most important establishment in high efficient and quality crop production. The control of the greenhouse environment, especially the intelligent control, is an importance research task in the facilities agriculture .In recent years, many domestic and international researchers have done a large amount of research work in this field. But the control of greenhouse environment is a very complicated engineering, and now, in which there is still a lot of research work to do.In this thesis, the author researched the control arithmetic of greenhouse. Imitating the person's logical inferential process, adopting the Fuzzy PID controller to control the greenhouse climate parameters. Advanced a control strategy of the greenhouse intelligent control, named, greenhouseMulti-factors combination and divided state control strategy". In this strategy, the greenhouse' s working state was predigested and divided to 10 main working states, the working state of greenhouse lies on the inference rules of the crop expert system according to the ideal environment climate parameters and current actual environment climate parameters.Appling computer technology, sensor technology, instrument technology and advanced PID control technology, the author designed a intelligent control system of the greenhouse , which based on the crop planting expert system. The Control system' s hardware include two parts, personal computer and PLC(SIEMENS S7-200 ), this is an expansive DCS control system. This system could collect the climate parameters of the greenhouse, such as temperature, humidity, carbon dioxide and illumination, also control them effectually. The system' s software includes also two parts. The control interface was developed under MCGS environment, its function primarily is to keep-watch the working state of the greenhouse, the query and modification of the crop planting expert system, to output the control instruction to PLC. The program of PLC was realized under the software, STEP 7- Micro/ WIN32. It' s function is to collect sensors signal, to calculate the control parameters and output them to executive equipment.Greenhouse "Multi-factors combination and divided state control" expert control system, not only be applicable to keep-watch and control the greenhouse environment, but also be applied to control storage environment. This system has friendly interface, convenient operation universal, adaptability, and high reliability.