Parameter optimization and simulation analysis of floating root cutting mechanism for garlic harvester

Abstract

Root cutting is an essential step in the mechanized harvesting of garlic. A floating root cutting mechanism was developed to improve the root clearance rate and bulb damage rate for garlic harvesting. Mechanical models of bulb collision and root cutting were presented to theoretically analyze the forces on the bulb and root. Mathematical models of the root clearance rate and bulb damage rate were established to optimize the parameters of the floating root cutting mechanism. A rigid–flexible coupling simulation model of the garlic floating root cutting mechanism was built to clarify the dynamic characteristics of the floating root cutting process. An experimental system was developed to verify the performance of the floating root cutting mechanism. Analysis and experiment results showed that high-speed cutting was beneficial to an upright and efficient root cutting for unsupported roots; the collision damage of the bulb could be reduced by optimizing the conveying speed of garlic and the boundary dimension of the contact region of the root cutting mechanism; the optimal parameter combination was a conveying speed of clamping chain of 0.8 m/s, rotational speed of cutter group of 1450 rpm, cutter plane angle of 30°, and protective grid pitch of 35 mm; an unsupported root cutting of garlic could be realized at a rotational speed of cutter group of 1450 rpm, with a minimum distance between fracture point of root and root disc of 3 mm, and maximum deviation distance of root mass center of 48.48 mm, meeting the requirements of garlic root cutting quality. This study provides a theoretical and simulation model reference for the design, analysis and optimization of the floating root cutting mechanism for garlic harvester.