DEVELOPMENT AND TESTING OF A VARIABLE-RATE SEEDING MONITORING AND CONTROL SYSTEM FOR UNMANNED TRACTOR-TOWED SEEDING MACHINES

Aiming at the problems of poor seed distribution uniformity and low sowing accuracy in traditional sowing operations, this paper studies and develops a variable-rate monitoring and control technology system based on an unmanned tractor-towed seeding machine. The system adopts a distributed controller architecture, including a cooperative control ECU, a seed-metering monitoring and control ECU, and a sowing depth monitoring and control ECU, achieving multi-source information interaction and cooperative decision-making through a CAN bus. In terms of hardware, the seed-metering device's electric drive scheme has been improved by replacing the original split-type chain transmission scheme with an integrated torque servo motor, enhancing the system integration and transmission efficiency. Field test results show that the optimized electric drive seed-metering device, at forward speeds of 4 km/h, 8 km/h, and 12 km/h, outperforms the traditional ground wheel-driven method in terms of seed spacing qualification index, standard deviation, and coefficient of variation. Especially under the medium-speed condition of 8 km/h, the performance is optimal, with the coefficient of variation as low as 6.45%. The system demonstrates good robustness and adaptability in complex field environments, providing reliable technical support for achieving precise, efficient, and intelligent sowing operations.