青梗白菜收获低损伤性动态机理分析与试验

Analysis and Experiment on Dynamic Mechanism of Low Damage Harvesting of Brassica campestris L. ssp. chinensis var. communis

摘要:

针对叶菜收获过程人工收获费时耗力，机械收获机-菜互作机理研究不足，导致机具因作业参数不适配引起植株损伤率高的问题，本文以土下切根作物青梗白菜为研究对象，建立土壤-根系-割刀多体耦合运动模型和夹收损伤模型，分析植株在切根、夹持、集收过程动态机理，揭示损伤率主要影响因素割刀摆动频率、夹持输送带倾斜角及夹持输送速度与前进速度比的关系。运用离散元仿真分析方法建立土壤-根系-割刀团聚体模型，确定割刀最佳频率为4～22 Hz。在标准型和改进型参数的基础上，以切割频率、夹持输送带倾斜角、夹持输送速度与前进速度比为试验因素，以叶菜损伤率为试验指标进行单因素和三因素三水平正交优化试验，得出最优参数组合为切割频率7 Hz、夹持输送带倾斜角18°、夹持输送速度与前进速度比2.1，最优参数组合田间试验平均损伤率为2.12%。研究结果为叶菜低损收获技术研发提供工作参数选取依据和理论基础。

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.