Study Of Design And Experimentation On Intelligent Environmental Measure And Control System In Greenhouse

This text summarizes the current situation of the development of the domestic and international greenhouse, and puts forward that the greenhouse goes towards maximization, intelligent and networked development trend. Practices of Agricultural production proved that increasing the input in science and technology of the greenhouse, improving automatic control and management level of the greenhouse can give full play to the efficiency of the agriculture of the greenhouse, and accelerates the factory and informationalized developing steps of agricultural production greatly, and promotes the change of the agricultural mode of production.To that the greenhouse of our country is low in scientific and technological content, the level of production lags behind, the modernized intellectual greenhouse nearly all rely on the import situation, this topic adopts advanced computer technology, micro-electronic control technology and sensing technology to design the distributed automatic control system of the greenhouse computer, this system makes up of one personal computer and a lot of controller control device, which make up a principal and subordinate type distribute structure the slave machine adopts PIC single chip microcomputer which has a high price performance rate, and realize the collection of the environmental parameter data of the greenhouse and control the system mainly. The master machine makes up of a personal computer, which is used to control environmental parameter and establish environmental parameter work mainly. System adopts RS-485 bus communication network which way of communication is half duplexing and accumulate and check-up communication algorithm, which are carried on data transmission. Utilizing VB6.0 to face target's database programming technology and Access database software, friendly man-machine interface is developed. By reading and storing the environmental parameter value in the greenhouse in real time, the management to four greenhouse environmental parameters, such as temperature, humidity, illumination and CO2 density is realized, which can be consulted conveniently.In the control system of intelligent greenhouse, in order to monitor the working condition of each machine in real time, and guarantee that device of temperature control. Device of humidity control, device of ventilation, device of lighting work safely. Electric current of 3 phrases AC should be gotten and monitored, which can guarantee the machine work normally, safely and reliably. This text shows principle of the way to realize the function of electric current measurement and method of implementation automatically, and provides detailed principle picture and software flow chart of the measurement of electric current. We utilize the mutual inductor to take a sample to the three-phase current, and sample which is enlarged, rectified, filtered, is send into PIC single chip microcomputer to deal with. The size of three- phase current on the line is calculated out, which offer the accurate value for the change of controls the equipment state.Experiment research shows: this system has certain precision of observing and controlling, according to the need that the crop grows, this system has realized the automatic regulation to four kinds of main environmental factors in the greenhouse which is temperature, humidity, CO2 andilluminance, and this system have offered the good growth condition for the crop is grown rapidly, high-quality, high yield. This system is easy to operate; the interface is friendly, offering the real-time change of various kinds of environmental factors in the greenhouse to observation in the form of dynamic curve. By revising environmental control parameter, this system realizes the purpose of interfacing operation online in a real meaning. System also have these characteristic which include: working reliably, high price performance rate, upgrading easily etc.