Design Of Variable Rate Spraying Control System Based On ARM

Pesticides are indispensable production materials for the prevention and control of crop pests,diseases and weeds.The amount of China’s pesticide use is massive and the average pesticide utilization rate is still low,resulting in a series of problems.Rationally reducing the use of pesticides and effectively increasing the effective utilization rate of pesticide is the main direction of precision agriculture.In this paper,a variable rate spraying control system was designed based on analyzing and comparing the domestic and foreign variable rate spraying methods,and field experiments were conducted.The main research content includes:1.Variable Rate Spraying Control System hardware design.The ARM-based control platform was designed.The wheel speed detection device,real-time flow detection device,pressure detection device,and flow adjustment device were developed.The ECAN module in the microcontroller PIC18F2580 was selected as the CAN controller and the TJA1050 chip as the CAN transceiver.The CAN bus network was established with each device as a node.The control platform can obtain the speed of the vehicle,real-time flow,pressure,and other feedback information collected by the CAN bus,perform real-time data processing according to the program,send corresponding instructions to the flow regulation device,and change the current spray volume.2.Variable Rate Spraying Control System software design.Based on Linux-C language,the lower computer software is designed to control the character devices of ARM to realize CAN bus communication,receive and process the data collected by each detection device,and control the flow adjustment device according to the designed control scheme.Based on Qt,the upper computer display interface was designed to display the key operating parameters of the current sprayer in real time and generate a spray amount curve,which helps the driver to know the history of the amount of spray and the overall trend during one operation.3.Field experiments.With the variable rate spraying control system installed on the 3WQ-3000 trailed boom sprayer,a series of field experiments were conducted in Agro-pastoral thoroughbred farm in Shaanxi Province.The speed detection accuracy,the variable control accuracy,and the impact of the system on effective utilization of pesticides were tested separately for the variable rate spraying control system.The test results show that:within the range of the sprayer’s working speed 4～10km/h,the control error of the system is less than 5%,which meets the requirements of spraying operations.