宽苗带小麦播种机多行匀播分控系统设计与试验

Design and Experiment of Multi-row Uniform Seeding Control System for Wide-row Wheat Seeder

摘要:

针对长江中下游农业区稻茬田宽苗带小麦播种机曲线作业时各行播量不均匀的问题，设计了一种宽苗带小麦播种机多行匀播分控系统。通过多速率GNSS/IMU组合导航系统获取播种机组运动信息，根据机组刚体空间运动学模型计算各播种单元匀种器地面速度，结合宽苗带播种农艺要求得出排种器驱动电机转速控制量;基于CAN通讯和PID控制器，应用STM32单片机分别控制各排种轴转速，实现宽苗带小麦播种机曲线作业多行匀播。路面试验结果表明，当IMU传感器、RTK-GNSS采样速率分别为20、10 Hz时，组合导航系统播种机组运动信息估计精度优于其它组合，此时匀种器地面速度估计平均相对误差为4.18%，其方向同播种机组航向夹角估计平均相对误差为11.26%，各行播种均匀性变异系数平均值为7.68%;田间试验结果表明，不同作业路径下，宽苗带小麦播种机多行匀播分控系统各行播量合格指数不低于94.90%，各行变异系数不高于0.97%，满足长江中下游农业区小麦宽苗带播种农艺要求。

Abstract:

To address the issue of uneven seeding rates across rows during curved operations of wheat seeders in rice stubble fields in the middle and lower reaches of the Yangtze River agricultural zone, a multi-row uniform seeding control system was designed for wide-row wheat seeders. This system employed a multi-rate GNSS/IMU integrated navigation system to acquire the motion data of the seeder unit. Using the rigid body kinematics model, the ground speed of each seeding unit’s uniform seeder was calculated. The metering device’s drive motor speed was then controlled to meet the agronomic requirements of wide-row sowing. The STM32 microcontroller, combined with CAN communication and PID controllers, adjusted the seeding axis speed to achieve multi-row uniform seeding. Road experiment results indicated superior accuracy when the IMU sensor sampling rate was set at 20 Hz and the RTK-GNSS sampling rate was set at 10 Hz, with an average relative error of 4.18% in seeder ground velocity estimation and an average relative error of 11.26% in the angle between the velocity direction and the heading of the seeder, and the average coefficient of variation of seeding uniformity in each row of the system was 7.68%. Field experiment demonstrated that each row’s seeding quantity index in the multi-row uniform seeding control system for wide-row wheat seeder, under different driving paths, was consistently not less than 94.90%, with a coefficient of variation for each row not exceeding 0.97%. This system can meet the agronomic requirements for wheat wide-row seeding in the agricultural region of the middle and lower reaches of the Yangtze River.