Research And Development Of Intelligent Seed Platoon System With Outer Groove Wheel

Sowing operation is a necessary process in agricultural production,and the outer trough wheel seeder is widely used in sowing operations in China.Traditionally,the ground wheel drives the seeder,but the field operation environment is complicated,and the ground wheel is subject to greater resistance due to the need to drive more than ten seeders to work,and the ground wheel slippage occurs from time to time,which has a great impact on the uniformity of the seeding.In addition,the speed ratio driven by the ground wheel is relatively fixed,which affects the adjustment range of the broadcast volume to a certain extent,and the broadcast volume relationship needs to be redetermined when changing the speed ratio.In order to solve the above problems,this paper designs a set of intelligent seeding system with STM32F103R8 main control unit based on the outer slot wheel seeder,which has the functions of sowing amount adjustment,seed control,slot wheel working length control,lack alarm and so on,and the realization of the system is of great significance in improving the sowing quality,reducing the sowing failure rate,and improving the intelligent level of the seeder.In this paper,the effective working lengths of the slot wheel are selected to be 12 mm,27 mm and 42 mm,and the key parameters such as seeding operation parameters,seeder operation speed,and row shaft speed are designed,and the fuzzy PID control method is used to complete the closed-loop control of the speed of the brushless DC motor,and then realize the sowing control.Through Simulink simulation,the control effects of traditional PID control,incremental PID control and fuzzy PID control are compared,and it is concluded that the fuzzy PID control is 0.11 s shorter than the incremental PID control,and the response time is 0.28 s shorter than the traditional PID control,and there is no speed deviation in the stable operation stage of the motor and no overshoot in the start-up stage.Through the calibration test,the fitting relationship between the discharge amount of the outer groove wheel seeder and the speed of the seeding shaft and the relationship between the speed and duty cycle of the brushless DC motor were found.The prototype test shows that the maximum deviation between the theoretical speed and the actual speed of the seeding shaft under the control of the fuzzy PID controller is 1.25 rpm,the minimum deviation is 0.19 rpm,and the average deviation is 0.62 rpm.The maximum deviation rate was 3.71%,the minimum deviation rate was 0.97%,and the average deviation change rate was 1.94%,which had little impact on the broadcast volume and had good control effect.The maximum deviation rate between the theoretical sowing amount and the actual sowing volume of the intelligent seeding system is 1.91%,and the maximum sowing variation coefficient is 1.68%,which is less than the maximum sowing variation coefficient required by the seeder machinery industry standard of 1.8%.