Authors

Abstract

To address the lack of reliable discrete element method (DEM) parameters for wheat leveling using grain leveling robots, Wan Ken Mai 22 wheat grains were selected as the research material. Intrinsic and contact parameters – including static friction, coefficient of restitution, and rolling friction – between wheat grains, steel plates, and rubber surfaces were determined through physical experiments. Using the angle of repose as the response variable, Plackett–Burman, steepest ascent, and Box–Behnken experimental designs were employed to identify significant factors, determine optimal parameter ranges, and obtain optimized parameter combinations. The reliability of the calibrated parameters was verified using a t-test comparing simulation and experimental results. The results indicate that the static friction coefficient, coefficient of restitution, and rolling friction coefficient are 0.5023, 0.4700, and 0.1110 for wheat–steel; 0.622, 0.419, and 0.137 for wheat–rubber; and 0.53, 0.52, and 0.04 for wheat–wheat contacts, respectively. The simulated angles of repose (27.57°, 27.25°, and 26.83°) showed no significant difference from the experimental values (P = 0.5485 > 0.05). The calibrated DEM parameters provide a reliable basis for structural design, parameter optimization, and coupled simulation of tracked grain leveling robots.

Abstract in Chinese

针对平粮机器人平整小麦过程中缺乏适用离散元仿真参数的问题，以‘皖垦麦22’籽粒为研究对象，采用物理试验测定籽粒本征参数及与钢板、橡胶间的静摩擦系数、碰撞恢复系数和滚动摩擦系数。以堆积角为响应变量依次进行Plackett-Burman试验、最陡爬坡试验及Box-Behnken响应面试验，筛选出显著性影响参数、确定出最优参数区间并优化参数组合，并对仿真结果与物理试验数据进行T检验分析验证可靠性。结果表明：小麦籽粒与钢板的静摩擦系数、碰撞恢复系数、滚动摩擦系数分别为0.5023、0.4700、0.1110；与橡胶的对应系数分别为0.622、0.419、0.137；籽粒颗粒间的对应系数分别为0.53、0.52、0.04。仿真堆积角（27.57°、27.25°、26.83°）与物理试验值无显著差异（P=0.5485>0.05）。本研究标定的离散元仿真参数可为履带式平粮机器人平粮装置的结构设计、工作参数优化及耦合仿真分析提供参考。