Research On Soil Environment Monitoring System Of Ecological Unmanned Farm Based On Wireless Sensor Network

Soil is an important material basis for crop growth,and timely monitoring of soil moisture content and soil temperature can improve crop quality and yield.In order to design soil monitoring equipment suitable for ecological unmanned farms,this paper describes the current research status of soil environment monitoring systems,and proposes a soil environment monitoring system for ecological unmanned farms based on wireless sensor networks.The specific application technology of the three-layer structure of the soil environment monitoring system’s perception layer,network layer and application layer is analyzed in detail,and the overall scheme of the system is designed.According to the crop management requirements of the ecological unmanned farm,the perception layer has designed a wheat field wireless sensor network based on Lo Ra,The system includes six sensor nodes and two acquisition nodes.The acquisition nodes are composed of a control unit,a sensor unit and a power supply unit.The control unit is based on the ESP32 main controller.The main tasks it enables the collection node to complete include multi-sensor task scheduling,data collection and transmission,node sleep wake-up,and OTA update.The gateway node is composed of two ESP32 main controller,Lo Ra module,Wi Fi module and OLED display screen.The main tasks completed include channel configuration,data transmission and reception control,display and storage processing.Use C++ language to complete the programming of the acquisition node and gateway node.The network layer is based on a wireless sensor network composed of Lo Ra communication technology,combined with Wi Fi communication to realize signal transmission and data exchange.The application layer is composed of a server and a client.After being parsed and verified by the server,it is written into the SQL Server database and One NET cloud platform to realize remote query and analysis of soil environmental data.In this paper,the effective communication distance of the system and related influencing factors are tested.The communication performance test is based on the effective communication distance of a single node.The test results show that the coefficient of determination of the Shadowing signal attenuation model fitted by the measured signal strength attenuation curve is greater than 0.95.When the collection node is 600 m away from the gateway node,the signal receiving strength RSSI is more susceptible to interference from the external environment.The data transmission performance test is carried out by a multi-node wireless sensor network system.From the perspective of signal attenuation and packet loss,as the communication distance increases,after more than one kilometer,the system communication quality when the carrier frequency of the collection node is 433 MHz or 434 MHz Preferably,the packet loss rate is less than 3%.According to the evaluation test of the spatial heterogeneity of soil environment,the relative average deviation MRD of soil moisture content is less than 0.1,and the relative average deviation MRD of soil temperature is greater than 0.2.The spatial distribution of soil temperature is worse than that of soil moisture content.The difference in soil moisture content or soil temperature of different collection nodes at the same depth of soil is similar.The minimum power consumption of this system is about 4W.It has the advantages of stable performance and reliable data.It can be used in large-scale unmanned farmland to provide theoretical basis and data support for crop field management and growth model establishment,and is helpful to the promotion of agricultural modernization in my country.Development is of great significance.