Design Of Greenhouse Intelligent Control System Based On Fuzzy Control

The application of fuzzy control technology in micro-environmental control system for greenhouse is researched in this paper. On this basis a set of intelligent control system for greenhouse has been developed and obtains good control effect in practical use.Firstly, the environmental factors which affect the growth of greenhouse crops are introduced. And the functions and features of each actuator used to regulate the environmental parameters in greenhouse are analyzed comprehensively. Based on the analysis above the overall scheme of this intelligent control system is determined according to the requirements of micro-environmental control system for greenhouse.Secondly, in consideration that the greenhouse micro-environment is a multivariable, strong-coupling, large-lag, and time-varying controlled target, we can neither set up accurate mathematical model, nor obtain ideal control effect via regular switching value or PID control. On the basis of previous research results, an intelligent fuzzy controller based on fuzzy control theory is designed in this paper.Thirdly, this paper designs hardware and software of the fuzzy control system. The hardware consists of upper computer, lower computer and wireless sensor network. In order to improve the stability and reliability of the system, an industrial personal computer (IPC) is used as the upper computer and the lower computer is a PLC; the management software of upper computer is developed based on C#and Microsoft.NET Framework platform, the program of lower computer is programmed via Step7micro-win sp6, and the communication program between wireless sensor network and upper computer is developed via TinyOS platform and nesC language.Finally, this paper takes control effect of two parameters (temperature and humidity) as an example to give an analysis on actual control effect of the fuzzy control system. The test result shows that this control system has stable and reliable performance, small overshoot in control process, good stationarity, short response time, and relatively ideal control effect.