Dynamic model for metering process for pneumatic roller-type vegetable seeder

For designing high performance pneumatic roller-type metering device, the seed was simplified as single rigid body, its dynamic models during metering process was built. By theoretic analysis and experiments, main factors of seeding effects were discussed. During absorbing phase, properly selecting roller material to add friction coefficient between seeds and the roller, increasing airflow rate, decreasing distance between seeds and metering holes, the absorbing effect can be greatly improved. In order to ensure that the seeds can rotate with the roller to their metering positions, the metering holes should be designed according to the average seed diameter, the depression of air in the air chamber should be properly adjusted, and the maximum circumferential speed of the roller should be limited. Structure of air chamber should be optimized for achieving uniform air field distribution of each metering hole, to minimize the effects of jet stream on metering precision.