Airflow ejection-wrapped clamping type seedling picking method and parameter optimization

Guoxin Ma; Xi Chen; Yang Liu; Luhua Han; Hanping Mao; Jianping Hu

doi:10.3389/fpls.2022.1084563

Airflow ejection-wrapped clamping type seedling picking method and parameter optimization

Front Plant Sci. 2023 Jan 12:13:1084563. doi: 10.3389/fpls.2022.1084563. eCollection 2022.

Authors

Guoxin Ma¹, Xi Chen¹, Yang Liu², Luhua Han¹, Hanping Mao¹, Jianping Hu¹

Affiliations

¹ School of Agricultural Engineering, Jiangsu University, Zhenjiang, China.
² Xinjiang Academy of State Farms, Institute of Mechanical Equipment, Shihezi, China.

Abstract

Since the current clamp-type and push-out-type seedling picking method brought damage to seedlings, this study aimed to proposed an airflow ejection-wrapped clamping type seedling picking method, which used airflow to eject out seedling and the seedlings were wrapped clamped to reduce the damage of seedlings during seedling picking process. The parameter model was established through theoretical design, then the parameters were optimized through coupling simulation analysis, and the validity of these parameters was verified through experiments. We found that the diameter of the airflow nozzle was selected as 3.5 mm to match with the drainage outlet of the plug tray, and the airflow pressure which could eject out seedlings was calculated as 0.146 Mpa~0.315 Mpa on the basis of gas jet dynamic. The fluid-solid coupling simulation of airflow ejection in Comsol proposed that the seedlings could be ejected out under the airflow pressure was equal to or greater than 0.4 Mpa, and the airflow should be maintained for about 0.3 s to ensure the posture of the seedlings ejected out for better seedling clamping. The further fluid-discrete body simulation of airflow ejection by using Fluent-Edem coupling method indicated that the seedling was damaged under airflow pressure of 0.5 MPa, so the airflow pressure should be set as 0.4 MPa during seedling ejection process. Besides, a wrapped clamping type effector which clamped the seedlings from all sides in the form of flexible package was also designed to match with the airflow ejection method, and the RecurDyn-Edem coupling simulation showed that the end-effector could tightly clamp the seedling without damage when the angle between the clamping slices and the vertical direction was 8.5°. Finally, the airflow ejection-wrapped clamping type seedling picking device was manufactured, and the verification tests verified the simulation results. This research can provide some references for the automatic seedling picking technology.

Keywords: airflow ejection; coupling simulation; end-effector; seedling picking; test; wrapped clamping.

Grants and funding

This work was supported by funding from the National Natural Science Foundation of China (51975258), the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD-2018-87), the Key Research and Development Projects of Jiangsu Province (BE2021342), the Modern Agricultural Machinery Equipment and Technology Demonstration and Promotion Project of Jiangsu Province (NJ2021-08), and the Special Project for National Industrial Foundation Reconstruction and High-quality Manufacturing Development in 2021 (TC210H02X).