| It is an important role of greenhouse in the national product, which as indispensable facilities of modern agriculture. The development of greenhouse intelligent control system is slowly, and the modern management level is not high. However, the introduction of foreign advanced greenhouse control system, on the one hand, the price is expensive; on the other hand it does not necessarily match with domestic environment. Consequently, it is of great significance to develop a simple, economic, stable, and perfectly functional and expansibility Greenhouse intelligent control system which is suitable for China’s national conditions, which can speed up the modernization level of greenhouse production in China and improve the economic benefits of greenhouse.On the basis of analyzing the existing advanced domestic greenhouse control system, combining with advanced industrial control network theory, this project developed a greenhouse automatic control system based on MPI network. The system can achieve single greenhouse field monitoring functions, which use of PC as an external debugging equipment, PLC as the control equipment, MPI communication protocols, PC man-machine interface design.Firstly, the sensor deliver process parametric variable to controller, which are air temperature, air humidity and carbon dioxide, etc. After that, it compares correspondingly and process variables through the programmed control rules in advance. Finally, it can establish a good effect of greenhouse growing environment through the control program to drive actuator corresponding action, to compensate for regulating environment variable.Methods:Firstly, collecting Greenhouse information. It can analyze greenhouse environment variables with mathematical methods, and determine characteristics of the greenhouse microclimate environment, and make control system solutions according to crop growth requirements. Secondly, designing system hardware module and software module respectively based on the system scheme. The main work includes the construction of the hardware system, controller type selection, control program and the man-machine interface configuration. Finally, it is debugging system and perfecting the system function after the system built.The system can realize well the process control requirements in operation, which the control process is stable and reliable, with high cost performance. It is a kind of more economic network monitoring system of greenhouse. |
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