Abstract: Cell type metering device can not meet the needs of precision planting.One of the main reasons is that the device is not suitable for the variety of seed size.In this paper,a new type of vertical plate metering device filling in inside,i.e,precision metering device with concave metering inner cell is chosen as an example.Through the theoretical analysis and computer simulation of the clearing process of a small seed in metering inner cell,the result shows when the seeds in metering inner-cell are smaller,the main factors of affecting clearing process are the length of metering inner cells and the rotative velocity of the vertical-plate.

Key words: precision planting, metering device, clearing seeds, computer simulation