Operation quality control of rapeseed strip aerial seeding system via under-constrained seeding technique

Abstract

Due to the strong aerodynamic disturbance induced by high-speed rotating rotors and under-constrained seeding condition, it is difficult to control the width of landing seeds in target area during the aerial seeding process. In this study, based on the multi-rotor plant protection unmanned aerial vehicle (UAV) platform, the strategy of under-constrained seeding at a low dropping height is employed to realize the strip aerial seeding of rapeseed. Firstly, the spatial-temporal characteristics of downwash flow field in forward flight state are verified via the high-fidelity computational fluid dynamics method. Afterwards, the migration mechanism of falling seeds and operation parameter optimization are investigated by employing the gas-solid coupling simulation technique. Finally, flight experiments are carried out based on multi-rotor UAV platform to verify the validity of simulation results, where the image processing technique is used to accurately obtain the coordinates and distribution characteristics of landing seeds. The result indicates that the strip effect could be further improved with a higher flight speed and lower dropping height, for instance, the strip width of 95 % landing seeds could be controlled within 81.1 mm when the flight speed and dropping height are 3.5 m/s and 0.5 m respectively. The research results can provide a suggestion for scientific setting of operation parameters of aerial seeding system.