Seeding Performance Simulations and Experiments for a Spoon-Wheel Type Precision Cottonseed-Metering Device Based on EDEM

Abstract

To study the effects of seed metering on seeding performance under different motion parameters, a simulation model for a spoon-wheel type seeder was established. A seed meter was tested by using EDEM (Engineering Discrete Element Method) software to simulate its working process at different speeds and tilt angles. The trajectories of individual cottonseeds in the seed-metering device were obtained, concurrently, the stress trend in the grain group was determined as a function of time. The simulation results suggest that at larger speeds, the metering index of the seed meter gradually decreases, while the index and the missing index gradually increase. As the tilt angle increased, the multiples index and missing index gradually decreased, while the multiples index gradually increased. When the seed meter speed reached 50 r/min and the tilt angle was 15°, the seed meter had a relatively good working performance with a seed spacing acceptance index of 92.59%, a multiples index of 1.85%, and a missing rate index of 5.56%. The seed meter was tested on a bench by using a JPS-12 performance-tester bench. At the aforementioned speed and angle, the coefficient of variation for the cottonseed spacing was 2.1%. The field trial results indicated that the multiples and the missing rates were higher than those for the tester bench but still met a passing rate of more than 90%. The coefficient of variation for the seed spacing was less than 10%, suggesting that the design could be used for field sowing. The resulting seeding uniformity was higher under these conditions, which indicates that the seed meter has a better working performance and the bench has a good seeding effect.