Design Of Facility Light Environment Monitoring And Control System Based On Light And Temperature Coupling

Light and temperature is an important factor for crop growth process, but because of the effects of covered materials, dust, shading structure, and the haze weather, facility light is difficult to meet the demand of crop growth, artificial lighting technology can effectively improve light environment of facilities crop growth and photosynthesis efficiency, has become an important means and research hotspot for light environment control. Existing light environment control method usually adopts the way of fixed intensity or threshold control, without considering the interaction of light quality, light, temperature and other environmental factors, and the influence of that for photosynthetic rate of the crop, lead to insufficient or excess light. In view of the above problems, this paper developed a facility light environment detection and intelligent control system which has dynamic and adjustable light environment target value, and then the system detection accuracy and light environment control performance were validate, is for the purpose of the assessment of effective and energy-saving of light environment control, in order to provide reference for improved and research of intelligent control device for light environment.The main work and conclusions of this paper are as follows:(1) In order to improve the efficiency of light environment control, completed the design of intelligent control algorithm for light environment based on light and temperature coupling. According to the mechanism of crop photosynthesis, using tomato as the test sample designed two gradient photosynthetic rate test of adjustable photon flux density and air temperature, and constructed photosynthetic rate model of light and temperature coupling by the gross error filtering and nonlinear regression analysis for the test data; and completed the light environment target value optimization by genetic algorithm, obtained the light saturation point under the condition of different temperature, and then the optimal regulatory model of light environment was established aiming at light saturation points, through the comparative experiment of the model and found the maximum relative error between measured value and calculated value of light saturation point is less than 6%.(2) According to the actual demand of light environment control, researched and developed facility light environment intelligent control system based on light and temperature coupling. The system uses CC2530 processor as the core, the use of modular design, the system hardware design is completed through the Altium Designer hardware circuit design software, and then the node making and construction of hardware platform is completed; at the same time with ZigBee wireless transmission technology, based on the light environment target value model,using a dynamic feedback control mechanism, the light environment intelligent control algorithm is designed; then using C language to complete the design of software modules such as main program, monitor and control program, intelligent control program, and put them into the hardware platform of the system, thus completing the environmental information detection, self-organized network and generation and transmission of system control signal, realized the intelligent control of light environment for greenhouse tomato.(3) Through field deployment to verify the effectiveness and energy efficiency of light environment intelligent control system. Experimental results show that this system can be a long-term stable operation in the greenhouse facilities, effectively improve the light environment of facility tomato, effective energy saving up to 30%.In order to improve the facility agricultural light environment, this paper designed a target value dynamically adjustable light environment intelligent control system, the system can effectively improve the facility light deficiency and low yield problem of artificial cultivation, and to provide theoretical and practical basis for late research of light environment control technology and equipment research and development, has a certain reference value.