Design Of Distributed Automatic Irrigation Control System

The traditional irrigation method in which irrigation strategy is determined by human experience is prone to miscalculation and cannot trace irrigation information,which is obviously outdated,and with the advancement of the Ministry of Agriculture’s high standard farmland construction plan,there is an urgent need for farmland irrigation technology to step into automation and intelligence.In order to solve these problems,this paper designs a distributed automatic irrigation control system composed of four parts:irrigation monitoring node,convergence node,cloud server and client.The hardware design includes PCB design of monitor node and converge node,the core controller of both nodes is STM32F103RCT6,supplemented with power supply circuit,sensor circuit,LoRa module circuit,control circuit,GPRS module circuit and other peripheral circuits.The software design of the system includes C language programming,server environment configuration,database design,host computer programming,Web client design and Android App design.Finally,the monitoring nodes construct the wireless sensor and actor network according to the star network topology.The sink node obtains the sensor data of the monitoring node one by one according to the configured collection cycle,and uploads the data to the database of the cloud server.At the same time,the monitoring node will decide whether to irrigate according to the set threshold value.When the irrigation is automatically started,the irrigation duration will be recorded and uploaded after irrigation.Both the Web client and android app can manually control the irrigation and change the irrigation threshold,and the instruction is transmitted to the accurate monitoring node through the sink node.In addition,the web client can view the data of each monitoring node in the form of chart,and provide the function of downloading to the local in Excel file format.The wireless network performance test of the system shows that:the packet loss rate within 1.6km communication distance can be guaranteed to be less than 5%when the antenna with a height of 2m is set up in the relatively open farmland.In addition,the power consumption test of the system shows that:the average current of monitoring node and sink node is as low as 1.21mA and 30.10mA respectively.After that,the whole system was put in the field test at Guangyang Agricultural Science and Technology Planting Base in Fuping County.Through logging in to the cloud server and web client,it can be seen that the system automatically runs stably and can remotely monitor the soil information without losing data.The automatic control can accurately keep the soil humidity in the monitoring area within the suitable growth range of crops,and the control information is recorded in detail,The download function of the web page is normal.The system has the advantages of large monitoring area,low power consumption,low cost,easy installation,and has a good prospect in the field of agricultural irrigation.