Research And Design Of Precision Agriculture Greenhouse Monitoring System Based On Wireless Sensor Technology

Once,agriculture is the basis of national economy.As a main developmental direction of modern agriculture,there will be great significance for realization and appliance of precision agriculture in case of improving the level of agricultural production in China.Precision agriculture can be divided into three steps,which are field information acquisition,information-based decision-making and management,variable precision control.Unfortunately,the development of the three parts are relatively backward in China at present.For the reasons that field information acquisition is the premise of precision agriculture,therefore,based on this step,in case of temperature-sensitive high economical agriculture,a precision agriculture greenhouse monitoring system is designed.What is more,wireless sensor technology is used to obtain the main environmental parameters information of the greenhouse.The perception of temperature field is innovatively introduced to processing of the greenhouse environmental monitoring.Through this way,temperature field of different area in the greenhouse will be calculated.The main contents of this thesis are as follows:Firstly,the greenhouse physical model chosen in this thesis is analyzed in detail.And dividing subdomains trilinear interpolation algorithm is designed to be the calculation methodology of temperature field.Then the scheme of sensor nodes is proposed,the mathematical model of temperature field in the greenhouse is ultimately built.For verifying feasibility of calculation temperature field using molecular domain three-dimensional linear interpolation algorithm,calculation experiment is done by simulation the greenhouse environment in the lab.Furthermore,visualization of field temperature is realized with the help of Matlab.Secondly,through analyzing the function and the designing principle of the system,the wireless sensor network and the overall structure are constructed.The system is divided into four parts: upper computer,control unit,data acquisition unit and wireless sensor nodes.Environmental data,including to temperature,humidity,light intensity and carbon dioxide concentration are collected by the wireless sensor nodes located according to layout scheme.A wireless and a wired communication network are relatively constructed through wireless communication technology between data acquisition unit and control unit or RS485 communication between data acquisition unit and control unit.Meanwhile,the upper computer use the network serial port conversion module to communicate with each other by UDP protocol.By this way,All the environmental parameter data collected by wireless sensor nodes are transferred to the upper computer,which will calculate the temperature field and display the processing result of various kind of data.Thirdly,the technologies required by the system are analyzed theoretically and realized.The hardware design of the system is completed through reasonable component selection and circuit designation.According to the different functions,the programs of each unit are designed.Also,a visual interface based java is designed through Eclipse software.Therefore,a simplified operation upper computer system is born.Parts of the hardware units are made to test several major functions and verify the feasibility of the system.Combined with wireless sensor technology,embedded technology,communication technology,numerical calculation theory and computer technology,temperature,humidity,light intensity and carbon dioxide concentration monitoring of the crop growing area are realized.Besides,it is confirmed that the system has the advantages of good real-time performance and convenient operation.