The Key Technology Of Wireless Sensor Network For Precision Agriculture

Farmland is the natural resources which is not growth, improve the production efficiency of farmland, economic benefits and environmental benefits has become the significant problems need to solve of our country with the help of advanced technology means based on the limited farmland resources. At present,"precision agriculture" technology which with modern information technology and agricultural technology fusion as characteristics becomes one of the key supporting technologies to solve the above problems, and the use of wireless sensor network technology for farmland information collection and management, is the hot spot in the study of agricultural information technology.Wireless sensor network (WSN) technology is connect Sensor technology、Micro Electro-Mechanical System (MEMS)、Embedded computing technology and Distributed information processing technology together, Is easy to decorate, flexible control, low power consumption, convenient communication, low cost, etc. Different with the traditional public network communication technology, it is hard to find the complete reunification of the networking technology to deal with all sorts of different applications because of WSN is centered on the task or data. Therefore, It is necessary to design optimization, application of wireless network structure for different application areas and related requirements. And studies the corresponding networking technology, energy management, data management and integration methods.Precision agriculture application has the following features:Crop types and diverse topography、weather conditions complex, monitoring area is large、the sensor node number each node often configuration multi-source information (all kinds of soil properties, environmental attribute and crop growth information, etc.), crop growth cycle is longer, These characteristics of precision agriculture for wireless sensor network system application take challenges. In this paper be aim to good environment adaptability, low power consumption, low cost, standard, consider facility agriculture and two kinds of application objects in open field, studied key technologies of WSN of agriculture, including network structure, network mode, the node positioning method, method of data fusion, energy self-sufficiency and energy conservation strategy, and introduced the system performance evaluation method for WSN, the middleware design method for IOT, the general node software and hardware design method and the typical application systems. The main research contents and results were as follows:1. Firstly, experiments are respectively carried out on the bare ground, plains and mountain, starting from agricultural application environment on the wireless channel propagation characteristics, and established the wireless channel propagation loss model. It provides the basis for wireless sensor network organization structure, Network mode and methods for different application environment of nodes deployed.2. Discuss the network structure and network mode of precision agriculture WSN. Design the system architecture of wireless sensor network in view of the field and the practical application of facilities agriculture environment. The system adopts the limited since the network with cluster. And cross double chain communication way of communication is adopted.3. Use the improved DV-Hop algorithm to positioning nodes, this algorithm uses the four sides ranging positioning for the location node in field application. Design the energy supply method based on MPPT for agricultural multi-source information WSN terminal node, adopting solar energy combined with rechargeable lithium batteries, sensors work in intermittent sampling, deep sleep mode, can supply of energy rapidly.4. Data processing is an important part of agriculture WSN; Use compressed sensing theory based on space-time correlation to the network data fusion. It can reduce the transmission of data, and reduce the energy consumption effectively.5. At present, there is no wireless sensor network system industry standard for precision agriculture. In this paper designed agricultural wireless sensor network system evaluation strategies and evaluation method as the goal of the power and the power and quality of service based on the study of the above,it provide the reference for Wireless sensor network system industry standard used for precision agriculture.6. Finally, In order to deal with agricultural standardization of WSN working in low cost, and convenient data management needs. Design the middleware for IOT, and develops the software and hardware system for Irrigation in open field cultivation environment and facilities. The results show that the design of WSN technology is meet the demand of the application of precision agriculture, both of Hardware and software is convenient for system integration, Suitable for standardized requirements and large-scale promotion.