| Currently,there are many problems in the traditional light environment regulation,such as unscientific management,simple equipment,low efficiency and so on.Because the structure of most greenhouse are simple and the scale of those are small,the traditional illumination environment control methods are still adopted in most greenhouses.Only a few standardized glasshouses use the modern intelligent illumination environment control equipment.Traditional greenhouse light environment control equipment have the defects of high light energy consumption, uncontrollable illumination, unsafety and low regulation efficiency. And because the greenhouse environment is extremely complicated, it need to be calculated in the computer system under the control of a large number of data, which costs more and operation is complex.In this paper, in order to meet the need of light environment control technology in industrialized agriculture and system applications, combined with the situation of China’s family-agricultural production, the research of low-cost greenhouse light environment control system based on accurate and intelligent control technology was carried out. The main research results are as follows:(1) ZigBee2007is used as the wireless network transmission protocol, which was optimal allocated according to the facility environment and actual production application characteristics.TI’s CC2530was selected as the core processor of the greenhouse light environment control system. The intelligent master node is designed. And it was responsible for the network parameter selection, construction and starting the network, which was the establishment of environmental data transmission based on wireless sensor networks. At the same time the monitoring of environmental factors such as the greenhouse real-time temperature, carbon dioxide concentration, light intensity was completed, and the optimal light environment value of the current crop growth was precisely calculated to achieve the multi-factor coupling regulatory.(2)The terminal driver node based on CC2530was designed to receive the wireless regulation command of light intensity. Light intensity adjustable drive circuit was developed based on PT4115and continuous stepless control of LED brightness can be got using PWM technology.(3) Based on the mechanism of photosynthesis, using tomato as the research object, the experiments of the photosynthetic rate during seedlings at different temperatures were completed. Using matlab the tomato optimal light environment growth model was established. And then the light environment regulation model based on multi-factor coupling on the particular crop was completed. Eventually the optimal light algorithm was obtained, which realized light supplement accurately.Based on crop photosynthesis mechanism analysis, a greenhouse multi-factor coupling light environment intelligent decision technology was achieved. And integrating wireless sensor network architecture, greenhouse light environment wireless control system was designed By the testing and validation, the system has the characteristics of low power consumption, high security, precise regulation and low cost, which fully meet the need of light environment regulation in facility agriculture. |
