Study On Growth Condition Monitoring And Management Techniques Of Millet Field Based On Internet Of Things

The internet of things (IOT) technology marks another great leap of the global information industry after the born of computer and internet, which presents unprecedented opportunities to the rapid development of agricultural modernization. Study is carried out in this paper on growth condition monitoring and management techniques of millet field based on Internet of Things, and the main innovative points and working achievement are as follows.This paper briefly introduced the concept and architecture of IOT in agriculture, analyzed the key techniques of IOT in agriculture at three levels of information awareness, network transmission and processing application, summarized mainly the research and application status and remained problems of IOT in agriculture at both home and abroad, proposed the strategic priorities and measures of development of IOT in agriculture of China, and forecasted the application perspectives and development trends of IOT technology in the agriculture field. It was pointed that with the gradually establishing and improving of industrial standardization system of IOT and continuously promoting and mutual learning between different countries in key technologies, standards and application studies on IOT, major breakthroughs in core and key generic technologies would be expected, and the internet of things technology would move into a direction of more exhaustive awareness, more reliable connection, better optimized integration and more in-depth intelligent service, which would surely play a more important role in promoting the convergence of informatization and agricultural modernization and accelerating the development of agricultural modernization.1. Aiming at problems of previous agricultural wireless sensor network, such as high cost, high energy consumption and non-ideal transmission performance, this paper designed with chips of AT86RF212 and C8051F920 a new type of wireless sensor network which works on a Chinese dedicated band of 780MHz and is compatible with the IEEE802.15.4c standard for greenhouse. This paper briefly described the structure of wireless sensor network node, mainly introduced the hardware design of 780MHz wireless sensor network, chose typical solar greenhouse in the north area and the millet field at agricultural experiment station of Shanxi Millet Industrial Technology System as the experimental environment for research, and also tested and analyzed the received signal strength index (RSSI) and the average packet loss rate (PLR) of the wireless sensor network node in 433 MHz,780 MHz, and 2.4 GHz bands by changing wireless communication distance. The experimental results showed that RSSI of wireless transceiver modules in the 3 different bands decreased with the increasing of communication distance.1) The RSSI values of the 3 wireless transceiver modules were similar to each other when the communication distance in greenhouse was less than 20m. When the distance went to 40-90m, module in 780MHz showed a slightly larger RSSI value than the 433MHz module while 2.4GHz module had the smallest RSSI. Within the 90m communication distance range in greenhouse, packet loss rates (PLR) of both 780MHz and 433MHz modules were 0. For 2.4GHz module, packet loss took place at distance of 80m and when it went to 90m the maximal PLR was 5%.2) When the communication distance was 50-90m between greenhouses, RSSI of 780MHz and 433MHz modules were close. RSSI value of 780MHz module was higher than that of 433MHz module when the wireless communication distance exceeded 90m. For the 2.4GHz wireless module, the RSSI value was lower than both 780MHzand 433MHz modules’when communication distance between greenhouses was 50-140m. Packet loss occurred to 433MHz module when the distance was over 100m and when it went to 140m the maximal PLR was 11%. Packet loss took place to the 2.4GHz module if the communication distance between greenhouses exceeded 70m and when it was over 135m the PLR reached 100%. For the 780MHz band wireless module, packet loss took place when the communication distance between greenhouses was over 125m and when the distance was 140m the maximal PLR was smaller than 6%, which allows the reliable wireless transmission between greenhouses to proceed.3) The average plant height of millet in the experimental plot is 120cm. If the wireless transceiver module is placed at 1m high in between the millet plants, the RSSI value of the 3-different-banded wireless transceivers in the millet field all decreases as the communication distance increases. As long as the communication distance is less than 40m, the RSSI values of 780MHz and 433 MHZ modules are close to each other; when it goes beyond 45m, RSSI value of the 780 MHZ module is greater than that of the 433 MHz module; and the RSSI values of 780 MHz and 433 MHz modules are obviously larger than that of 2.4GHz module in varied communication distance. For the 780MHz module, the packet loss rate (PLR) is always 0 within a 100m communication distance; the PLR comes to 13% when it is 140m; for the 433MHz module, the PLR is always 0 within a 60m communication distance; the PLR comes to 12% when it is 100m; and at 140m the PLR reaches to 100%; for the 2.4GHz module, the PLR keeps 0 within a 20m communication distance; the PLR is 9% at 40m; and the PLR goes to 100% at 100m.4) When the module is placed at 2m high, which is, the module is higher than the millet plant, the RSSI values of the 3-different-banded wireless transceiver modules are close to each other if the communication distance is shorter than 30m; when it goes longer than 30m, the RSSI values of modules 780MHz and 433Mhz are larger than that of 2.4GHz module; when communication distance is shorter than 210m, the RSSI values are close for modules 780MHz and 433MHz; if it goes beyond 210m, the RSSI value of 780MHz module is greater than that of 433MHz module. For the 780MHz module, the PLR keeps 0 when the communication distance is less than 320m; the PLR is 3% at 400m while 12% at 480m; for the 433MHz module, the PLR remains 0 when the communication distance is less than 60m; the PLR is 15% at 320m while 100% at 480m; and for the 2.4GHz module, the PLR is always 0 when the communication distance is less than 20m; the PLR is 11% at 100m while 100% at 180m.5) The transmission characteristics of the wireless sensor networks in 433MHz and 780MHz bands are obviously better than the long range transmission performance of WSN of 2.4GHz band in the applications of greenhouse environmental monitoring and field environmental information monitoring. And it is even superior for 780MHz band WSN as to transmission and communication quality performance. Since the plant and surrounding obstacles impact the transmission of the wireless signal, the antenna of the wireless module should be mounted at places higher than the plant canopy to get better transmission effect.2. Study was conducted on safe and efficient millet cultivation management techniques, intelligent diagnosis and control techniques of millet diseases and pests, and integrated application of Internet of Things technology in aspects of millet field environmental information monitoring, millet growth remote monitoring and warning and intelligent water-saving irrigation, etc.. Fully applying perceptive technology of Internet of Things, reliable transmission technology, intelligent control technology, a modern agricultural production management mode of superior quality, safety, high yield, efficiency, ecology and saving-cost is established through full perception of millet growth environment, stable transmission of monitoring information and intelligent processing of data. Focusing on the build of millet field environmental information monitoring system, intelligent water-saving irrigation system, intelligent laser audio anti-bird system, system of safe and efficient millet cultivation guidance and intelligent diagnosis and control of pests, etc., it is realized of accurate perception and precision management, which thereby increases the production of millet, reduces input, cuts down labor consumption, saves cost, improves quality, and achieves good economic, social and ecological benefits.1) The millet field environmental information monitoring system is able to obtain the real-time remote transducer data of the millet field environment. For example, air, temperature and humidity, soil temperature and water content, illumination intensity and video images, etc.. The historical changes and trends of varied environmental factors can be called remotely through data base to achieve chart analysis and display, which provide data foundation for the accurate decision-making of water-saving irrigation.2) Field monitoring data acquisition:traditionally field parameter information is obtained in the artificial way or through wired connection; however, to get the soil moisture content parameters and other field environmental information by the wireless transmission way increases the integrity and reliability of the monitoring data to a great extent. In this experiment, multi-hop self-organizing network of 780MHz banded wireless transducers were multi-deployed in the millet experimental plot at the plant station. The transducers controlled by nodes in the network are used to get data. The node works not only to obtain, process and send data, but also to provide routing function to make a distributed transducer network and collect real-time experimental plot field information.3) Data reporting mechanism:currently, environmental parameter value is reported at a fixed time interval by wireless transducer node that is widely used in field environmental parameter monitoring. If the interval is set too short, frequent wireless transceiving leads to high power consumption for the node and thus shortens the duration working hours of the batteries; if the interval is set too long, the environmental parameter changes can not be real time monitored. In this paper it is designed to report data as long as the field environmental parameter value reaches the preset range ability (for example, air temperature variation ±1℃ or soil moisture change ±2%), and the reporting threshold of the parameter value range ability can be preset according to accuracy of monitoring. Comparing to the data report mechanism at fixed time intervals, this method conforms to agricultural production reality, monitors the real-time field environmental parameter change and reports to the control center; when the parameters is stable, it does not conduct frequent data transmission, which saves power consumption.4) Millet is drought-enduring only in its growth stage. In other growth stages, if millet suffers from drought crop reduction will be inevitable. Therefore, it is very necessary to irrigate timely based on the water demand of millet, which ensures high yield of millet. This paper summarizes the general pattern of water demanding in the whole growth period of millet and highly efficient water-saving irrigation system in the main areas, and builds intelligent water-saving irrigation system of millet based on Internet of Things. Reasonable irrigation is achieved by following the water demand pattern in varied growth stages and the soil moisture content information, which ensures timely water use of millet, achieves good quality and high yield and also provides a demonstration effect of water-saving.5) Millet growth condition remote monitoring system includes parts like solar power supply module, digital image transducer and controller module,3G mobile communication module,780MHz wireless communication module, wireless image transmission relay and control center server. By timing picture taking of monitoring area of the millet field with 3G network camera and wireless transmission of high definition images to remote server, monitoring to millet growth and disease, pests and bird damage is achieved to allow users to observe the growth of millet easily.6) Bird damage is always a great concern to the millet planter, and in severely affected millet fields crop reduction or even a total failure occurs. Reports on prevention and control from bird damage to millet are not widely seen and few researchers conduct related study. This paper covers the primary pest bird categories that harm the millet field and the common anti-bird methods, and designs an intelligent laser audio anti-bird system with ultra-low power consumption by utilizing solar photovoltaic module, ultra-low power consumption single chip, laser anti-bird technique and biological bionic audio technique. It achieves highly efficient anti-bird effect in all weather and direction by applying anti-bird audio library and green laser with 532nm wave length, which is the most sensitive one to bird vision, and decreases the millet loss caused by bird damage in the context of doing no harm to birds. This system was mounted in the millet experiment plot at the plant station of Shanxi Millet Industrial Technology System in August of 2014 and good anti-bird effect was achieved, which proves this system is featured of low power consumption, high stability, positive effect, long duration, harmless to birds and no bird adaptation. 7) By referring to massive document and research data, the system of safe efficient millet cultivation technique guide and diagnosis and control of diseases, pests and weeds is built on the basis of combination of theory and practice, which is of great importance in resolving the outstanding problems and key production techniques, promoting the modernization level of the millet cultivation, increasing the production, quality and effectiveness, and ensuring the safe and efficient supply of food crop like millet. In building the safe and efficient cultivation technique data base of millet, it guides users to control the key factors of various links in the production process and keeps the production ecological system of "millet-environment-cultivation technique" in best production status. The intelligent diagnosis and control system of millet disease, pests and weeds, consists of 3 data base of 25 types of disease,54 kind of pests and 35 types of weeds, which includes 6 modules of user management, diseases/pests/weeds query, intelligent diagnosis of diseases/pests/weeds, control technique of diseases/pests/weeds, maintenance of diagnosis database and expert consultation.This system combines the knowledge system of diagnosis and control of millet disease/pests/weeds and the expert intelligent consultation system, which is very instructive and of great practical value. Through field video monitoring, users are able to be warned of pests, conveniently query and obtain relative message, image and control methods of millet pests, which makes it achieve self diagnosis and prevention control. Users can also consult vegetable expert for advice on difficult pests through the system and the expert provides remote guidance to agricultural techniques, which helps to reduce and prevent millet effectively from disease/pests/weeds, increase the millet production and improve the quality.