Design Of Measurement And Control System For Variable Application Of Highland Sprayer

China is a large country in the production and use of pesticides.It mainly use large-capacity,spraying method of coarse droplets.The effective utilization rate of pesticides is only about 36%,which wastes pesticides and pollutes the environment.At present,there are some problems such as large dosage and incomplete monitoring of application parameters in the middle and late spraying operations of high-pole crops such as corn and sugarcane.Therefore,this paper designs a variable application measurement and control system of high gap sprayer,which mainly includes the following aspects:(1)According to the preliminary investigation and determination of the main technical parameters and functional requirements of the system,the information acquisition,pipeline segmentation,flow and pressure control,monitoring system implementation and other schemes are compared and analyzed,and the overall scheme of the system is determined.(2)The system takes the STC89C52 single chip microcomputer as the lower computer,and allocates the resources of the single chip microcomputer pin according to the hardware schematic diagram of the system;designs the peripheral circuits such as power supply,data conversion,serial port communication with the help of Proteus software;selects the keyboard module and designs its function;builds the system hardware circuit according to the designed circuit and module selection.(3)The PID control model is constructed and PID control algorithm is designed according to the control principle of dosage and pressure,and the optimal setting parameters of PID algorithm are determined by simulating the PID and pressure control model with Simulink module in the MATLAB.(4)The login program,serial communication program,data processing and alarm program of upper computer are designed based on Lab VIEW graphical programming software,and the main program,initialization program,keyboard processing program,data acquisition program,serial communication program,control module program of lower computer are designed based on Keil μVision development tools.(5)According to the system hardware selection and combined with the actual test conditions,completed the test platform construction.The designed software program is introduced into the system for trial operation and debugging test,shunt flow control test,charge quantity control precision test,pressure control precision test and the test results are analyzed and summarized to verify the rationality of the overall design of the system and the design of the control algorithm.