Design And Test Of Electric Control System For High-speed Precision Sowing Of Corn Based On Beidou Navigation

With the rapid development of agricultural science and technology,the emergence of experimental sites such as "smart agriculture" and "unmanned farm",agricultural farming methods are also gradually developing in the direction of science and technology and intelligence.As an important part of corn farming,sowing has always been the focus of research.At present,the traditional corn planter mainly uses the ground wheel to drive the main shaft of the seed metering device to implement extensive seed metering.This method has simple structure and is easy to slip the ground wheel,resulting in missed sowing and replay.Under the background of agricultural development of straw returning to the field,the difficulty of sowing operation is increased,and the quality of traditional mechanical sowing operation is reduced.In order to improve the uniformity of seed metering and the efficiency of the system,based on the Beidou autopilot unit and the double closed-loop fuzzy PID control algorithm,a high-speed precision electric control sowing system of corn based on Beidou navigation is designed in this paper.The system has the functions of sowing control and operation monitoring under autopilot.The main research contents are as follows:(1)Based on the Beidou autopilot unit,the combination of autopilot and electric seed metering is achieved by directly analyzing the longitude and latitude signal sent by Beidou navigation equipment for motor drive.(2)The motor control adopts double closed-loop fuzzy PID control algorithm to accurately regulate the motor speed and shorten the motor response time.(3)CAN communication is used as the system signal transmission medium to increase the fault tolerance and expansibility of the system.The upper computer is developed as the system parameter setting and parameter monitoring interface to improve the intelligent level of the system.(4)The results of bench test and field test show that when the theoretical speed is 0～ 37 r/min,the difference between the actual speed and the theoretical speed is small,and the average error range is 0.353%.The qualified rate of sowing is more than 94.9%,the replay index is less than 2.58%,the missing sowing index is less than 2.95%,and the coefficient of variation is less than 4.89%.The field experiment shows that when the plant spacing of sown crops is G = 25 cm,according to the index requirements of JB/T10293-2013《Technical conditions for single grain(precision)planter》,the collected data are analyzed.The results show that the operation performance indexes of electric drive seed metering system in constant speed sowing and variable speed sowing are more than 93%,the re sowing index is less than 5%,the missing sowing index is less than 5%,and the coefficient of variation is less than 5%.The operation is stable and reliable,and has good practical performance.