Authors

Abstract

Physical property parameter measurements and simulation model parameter calibrations of Pak Choi seeds were conducted to address the lack of accurate parameters for discrete elemental seed discharging simulation tests in the seed-metering device. Firstly, physical tests were utilized to determine the basic physical parameters and contact parameters of Pak Choi seeds. The results of these physical tests served as the basis for determining the range of simulation parameters. The Plackett-Burman test was employed to screen out factors that significantly affected the simulated angle of repose from the test parameters, including static friction coefficient between Pak Choi seeds-Pak Choi seeds and rolling friction coefficient between Pak Choi seeds-Pak Choi seeds. The optimal interval of these two factors was determined using the Steepest Climb Test. Subsequently, the regression equation between the significance parameters and the angle of repose was obtained through the Central Composite Designs test, and the best parameter combinations were obtained with the measured stacking angle of 24.3° as the optimisation target value: Pak Choi seeds-Pak Choi seeds static friction coefficient of 0.486, Pak Choi seeds-Pak Choi seeds rolling friction coefficient of 0.104. Finally, simulation and bench comparison tests were carried out for stacking angle and Pak Choi seed discharger performance evaluation. The relative error of the angle of repose was found to be 0.288%, while average relative errors for qualified sowing rate, replanting rate, and missed sowing rate were all less than 5%. These results demonstrate that calibrated Pak Choi seed simulation parameters are reliable and can serve as a reference for design optimization of Pak Choi seed dischargers in academic research writing standards.

Abstract in Chinese

针对小白菜种子在排种器中进行离散元排种仿真模拟试验缺乏准确参数，对小白菜种子进行物性参数测量及仿真模型参数标定。首先，采用物理试验测定小白菜种子的基本物性参数及接触参数，以物理试验结果为基础，确定仿真参数范围，利用Plackett-Burman试验从各组试验参数中筛选出对堆积角影响显著的因素：小白菜种子-小白菜种子静摩擦系数、小白菜种子-小白菜种子滚动摩擦系数，并进一步通过最陡爬坡试验确定两因素最优区间。再通过二次通用旋转组合试验得到显著性参数与堆积角之间得回归方程，并以实测堆积角24.3°为优化目标值获得最佳参数组合：小白菜种子-小白菜种子间静摩擦系数0.486、小白菜种子-小白菜种子间滚动摩擦系数0.104。最后，开展了堆积角对比试验及小白菜排种器的仿真与台架对比试验，得到堆积角的相对误差为0.288%，排种器的合格率、重播率、漏播率的平均相对误差小于5%。由此表明，标定的小白菜种子仿真参数具有可靠性，可为小白菜排种器的设计优化提供参考。