Study On Supplementary Lighting System For Plant Growth Based On Wireless Sensor Network

The population in our country is large,the area of cultivated land is decreasing year by year,and the demand for food and vegetables is increasing.With the improvement of people's material conditions,people have higher demands for living quality,anti-seasonal vegetable demand is also rising.It requires that the yield per unit area of crops should increase more and produce large quantities of off-season vegetables.Greenhouse cultivation is an important way to solve this problem,it can not only improve land use efficiency,and the greenhouse environment is relatively easy to control.Through manual regulation,the greenhouse crops can not be affected by the seasonal climate and illumination intensity,then crop yield and quality will increase.In the growth process of crops in greenhouse,factors affecting crop growth are:light,temperature,humidity,soil,pH and so on.Among them,light is one of the most important factors affecting crop yield and quality.Light participate in the whole process of plant growth,not only affect the growth and development of plants,but also provide energy for the photosynthesis.Seasons and weather conditions affect lighting conditions.With the development of science and technology,the greenhouse light filling equipment is also constantly updated.LED agricultural fill light is an indispensable new product of modern agriculture.As the environment in greenhouse is relatively more humid,which has a higher request for cable control system.The application of wireless sensor network to plant supplentary lighting overcome the difficult of layout in the cable system,difficult to repair,difficult to promote,and the reliability of the system can be improved.In this paper,Zigbee technology is used to study the characteristics of Zigbee and GPRS/GSM,WiFi and Bluetooth wireless communication technology in the application range,system resources and transmission distance.It is found that Zigbee technology has short transmission distance,lower system power consumption,longer battery life,larger capacity of network,lower system module price,free network frequency,which is suitable for monitoring and control.These characteristics meet with demands of greenhouse.Take the coriander planting greenhouse for example,the effects of different light and ight intensity on the growth and development of crops has been analyzed.Red and blue LED light source that is most needed in the process of plant photosynthesis has been chosed.Plant supplementary lighting system with Zigbee technology is designed based on the above theories,which can be self-network between the nodes,complete wireless transmission,monitor and control the light intensity inside the greenhouse.The monitoring unit in the crop growth environment obtain the light intensity data transmitted by each node through the coordinator to achieve data transmission,visualization and storage.Control unit calculate the exact amount of light that plant needs through the analysis of data.And then control supplentary light through PWM dimming to achieve filling light for crops in the greenhouse in real-time accurately Through experimental testing and analysis,the system can basically achieve networking,data transmission and dimming function,the experiment proved that the system can run normally and it can be used in the greenhouse,provide a kind of feasible and efficacious method for agriculture.