Potato seed metering device is the core working component to achieve precise seeding of potato. Its seed metering performance is closely related to the dispersion degree of population. The dispersion degree of population is the key to ensure the smooth filling of seeds, and the seed layer height and seed layer disturbance of seed metering device are the key factors affecting the filling performance. This paper introduces the main structural forms of the existing potato seed metering device, analyzes the methods of mechanical disturbance and airflow disturbance to improve the population dispersion, and different seed feeding devices to control the seed layer height and population mobility in the seed filling area to improve the seed filling performance of the seed metering device. The problems existing in the seed layer disturbance control method of potato seed metering device were summarized as follows: there were few studies on the establishment of mathematical model of population disturbance and population motion analysis, and the methods for improving the seed filling performance of potato seed metering device by seed layer disturbance were prospected. An intermittent seed supply device with large and small seed boxes was proposed. The seed layer height was controlled by intermittent seed supply, and the population dispersion and population mobility in the seed filling area were increased by using the population disturbance generated by vibration, so as to provide reference for improving the seed filling performance of potato seed metering device.

Given the lack of accurate parameter values in discrete element simulation of sweet potato seedling mechanized recovery, a direct measurement and virtual calibration method was used to study the Discrete Element Method (DEM) simulation parameters of broken sweet potato stems and leaves. The intrinsic parameters, collision recovery coefficient and static friction coefficient of broken seedlings were acquired by physical experiments. Different parameter combinations were designed for DEM simulation. The intrinsic parameters of sweet potato leaves and other unmeasurable DEM simulation parameters were determined by stacking angle optimization simulation. Plackett-Burman test shows that the static friction coefficients of stem-stem and stem-steel and the rolling friction coefficients of stem-stem and stem-leaf all significantly influence the accumulation angle. The parameters that significantly influence the stacking angle of broken seedlings were sent to steepest ascent test and Box-Behnken test. The average stacking angle of 40.51° and the relative error of 0.972% indicate it feasible to calibrate DEM parameters by physical test and optimization simulation and the calibrated parameters can be used in DEM simulation of broken sweet potato stems and leaves.