Abstract:Due to the time-consuming and labor-intensive nature of manual harvesting of leafy vegetables, coupled with insufficient research into the interaction mechanisms between harvesting machinery and vegetables, leading to high plant damage rates caused by the incompatibility of operating parameters in machinery, taking the subterranean-root-cutting crop, Brassica campestris L. ssp. chinensis var. communis, as the research subject, a multi-body coupled motion model for soil-root-cutter interaction and a clamping damage model were established. The dynamic mechanism of plant cutting, clamping, and collection processes was analyzed, revealing that the primary factors influencing the damage rate were the cutter swing frequency, the inclination angle of the clamping conveyor belt, and the ratio of clamping conveyor speed to forward speed. Using discrete element simulation analysis, a soil-root-cutter aggregate model was established, determining the optimal cutter frequency range to be 4~22 Hz. Based on standard and improved parameters, single-factor and three-factor three-level orthogonal optimization experiments were conducted with cutting frequency, clamping conveyor belt inclination angle, and the ratio of clamping conveyor speed to forward speed as experimental factors, and the leafy vegetable damage rate as the experimental indicator. The optimal parameter combination was determined to be a cutting frequency of 7 Hz, a clamping conveyor belt inclination angle of 18°, and a clamping conveyor speed to forward speed ratio of 2.1. The average damage rate in field trials with this optimal parameter combination was 2.12%. The research result can provide a basis for selecting working parameters and a theoretical foundation for the research and development of low-damage harvesting technology for leafy vegetables.
