Design And Experiment Of Wheat Mechanized Uniform Seeding Control System Based On STM32

Wheat is an indispensable food crop worldwide,and stable wheat production ensures social stability in our country.Currently,China’s wheat production faces the severe problem of uneven sowing,which ultimately affects wheat yield.This paper designs a wheeled variable-speed robot platform,studies the variable-speed uniform sowing control technology,and controls the seeding motor speed to change in real-time with the traveling speed and target sowing rate,achieving variable-speed uniform sowing and conducting field sowing experiments.The main research work is as follows:1)The design of a wheeled variable-speed robot platform,including a walking steering mechanism,a self-driving control system,a positioning and navigation module,a control unit module,and a seeding device,enables the wheeled variable-speed robot to perform on-site steering,carry experimental equipment,transmit real-time driving data,and automatically change its speed.2)The design of a mechanized wheat uniform sowing control system uses the STM32F103VET6 microcontroller to control the seeding motor’s speed and is mounted on the wheeled variable-speed robot platform.It controls the seeding motor speed based on the real-time traveling speed signal and target sowing rate of the wheeled variable-speed robot,achieving uniform sowing.3)The design of a multi-level control method,based on the brushless DC motor digital model,uses the Simulink environment in Matlab and its rich module library to establish a motor control model for multi-level control algorithm simulation.The second level is current and speed dual closed-loop control using the PID control algorithm.The first level control adopts speed loop control.It compares various control algorithms through simulation and their results.The first level control ultimately uses the fuzzy PID algorithm,optimizing the fuzzy PID self-adjustment rule base parameters,changing traditional single control,improving the control precision of the designed algorithm,reducing response time,and achieving minimal overshoot and good control effects.4)The motor control program is written using Keil5 software,including multi-level control programs and control algorithm programs.The multi-level control program is divided into the first-level control program,the second-level control program,and the main function.The fuzzy PID algorithm control program and PID algorithm control program are written separately,ultimately achieving fuzzy PID control and current-speed dual closed-loop control.The designed control programs are integrated,and the main function is written to control the motor speed based on the real-time traveling speed of the wheeled variable-speed robot.5)Field sowing experiments were conducted,with various comparative tests designed.The results show that the sowing rate control accuracy under constant speed conditions is above 96.8%,with good seeding stability.Under variable speed conditions,the sowing rate control accuracy is above 95.1%,with stable sowing rate and small differences between actual and target sowing rates and smooth changes.Under constant speed conditions,variable sowing rate control accuracy is above 95.2%,with small differences between actual and target sowing rates and high precision.