Study On Sunlight Greenhouse’s Environment Intelligent Control System In Dry Northern Regions

The healthy growth of crops are mainly affected by temperature, humidity, light intensity, and a series of natural environmental factors. If we can control these environmental factors in the optimal growth range of crops,then we may can make crops be the best growth status and even can achieve the goal of highest input-output ratio. To built intelligent greenhouse is to control the natural environment factor automatic and precisely to make the crops in the greenhouse growth in a optimal state.This article analyzes the control object and the greenhouse environmental factors of greenhouse, and provides a structure and control method of the control system, Ultimately designed a distributed intelligent greenhouse monitoring system，It basis by a PLC controller and a PC installed a configuration software. The main hardware is a basic module PLC and its special function module, all kinds of greenhouse detection sensor, power source and the corresponding actuator and so on.The Software mainly includes the king-view software and programming software GX Developer of Siemens PLC.This control system can be running in two modes, automatic control mode and manual control mode. When the system run in automatic control mode, PLC automatic collect the corresponding greenhouse environment parameter values by a variety of sensors.And through the logic control program to control the corresponding parts of action automaticly. So we can make the environmental factors of greenhouse in a optimum fluctuation range.When the system run in manual control mode, the user can control the analog switch of the king-view manual picture to adjustment the greenhouse environment directly.By the communication of PLC and PC configuration software to make the function of human-computer interaction become true. The machine can collect the indoor information of current value of environment, the state of the actuators, alarm and so on by king-view software. Even can view the trend of greenhouse historical data, operating reports, database operations, etc.Through the test and analysis experimental, this system can basically achieve the expected design goal, but it remains to be further perfected to popularization and application in actual greenhouse.