Study And Application Of Intelligent Measurement And Control System Of Factory Agriculture

The factory agriculture intelligent control system is a computer automatic controlsystem gears to the modernized greenhouses. This system can construct the bestenvironment for the growing of all kinds of plants by adopting various ofequipments and methods to control the temperature, humidity, luminous intensity,ventilating in the greenhouse, according to climatic conditions of the internal andexternal environment of the room ---such as temperature, humidity, wind speed anddirection, and environmental parameters ---such as luminous intensity, CO2 density,aridity of soil, pH value and Ec value of the nourishing liquid, etc. This system ismainly used in the intelligent greenhouses and the up-grade of botanical gardensand sun greenhouses.Aiming at the structure of this system, we have designed the popular, raising andintelligent control framework to be the low, middle, high control applications,according to the differences of control parameter, control precision, area of thetrellis and levels of intellectism, which are named embedding technical basedcontrol structure, industrial computer based control structure and main computerplus programmable logic controller based control structure. Because factoryagricultural control system is a multiple input and output system consists of piecesof parameter, non-linearity and heavy delay, thus this systematic control strategy isbased on the agricultural expert system, and combines several intelligent controltechniques, such as PID +self-adaptive fuzzy control, neural network, etc. Becauseof poor working conditions of agriculture sensor, and the standards of itsrequirements in stability, consistency and fault-tolerant ability, we have designed theCAN (Controller Area Network )fieldbus based series agriculture special-purposesensor, according to three environmental parameters commonly used in factoryagriculture :temperature, humidity and luminous intensity.This system pays much attention to the national conditions, compared withsimilar foreign systems. It centered the self-designed greenhouse control specializedsoftware platform, and structures the intellectual control system in supporting thefieldbus and ethernet technology. It follows closely to the most advanced level ofthe world. Its key technology owns the independent intellectual property, and issuperior to the price. At present, there are many units are researching the automaticcontrol system of the greenhouse at home, however, it still just started indevelopment of control software platform and agriculture special-purpose sensor, soit is obvious to see the advantages.