燕麦和箭筈豌豆混合种子离散元模型参数标定与试验

为了更好地应用离散元法研究燕麦和箭筈豌豆种子的混播过程，提高种子离散元模型的准确性，结合实际试验和仿真试验对仿真参数进行了标定。通过抽样分别测量了燕麦和箭筈豌豆种子的本征参数，并建立了种子离散元模型。采用碰撞试验、斜面滑动试验和斜面滚动试验，分别对燕麦种子和箭筈豌豆种子与ABS塑料板间的碰撞恢复系数、静摩擦因数及滚动摩擦因数进行了标定，得到燕麦和箭筈豌豆种子与ABS塑料板间的碰撞恢复系数分别为0.441、0.435，静摩擦因数分别为0.506、0.454，滚动摩擦因数分别为0.059、0.047。基于堆积试验，利用最陡爬坡试验和二次回归正交旋转组合试验方法，以混合种子堆积角的EDEM仿真值与实际值的相对误差为指标，确定种间碰撞恢复系数、静摩擦因数、滚动摩擦因数分别为0.320、0.327、0.042。利用螺旋排种装置对标定结果进行了验证，得到仿真试验与实际试验的混合种子质量流率平均相对误差为1.76%，燕麦和箭筈豌豆种子的排种质量比平均相对误差为2.03%，验证了仿真试验的可靠性，标定的结果可用于燕麦和箭筈豌豆种子混播过程的离散元仿真试验。

Parameter Calibration and Experiment of Discrete Element Model for Mixed Seeds of Oat and Arrow Pea

In order to better apply the discrete element method to study the mixed sowing process of oat and arrow pea seeds and improve the accuracy of the seed discrete element model, the simulation parameters were calibrated combined with the actual test and simulation test. The intrinsic parameters of oat and arrow pea seeds were measured by sampling, and the seed discrete element model was established. Collision test, inclined plane sliding test and inclined plane rolling test were used to calibrate the collision restitution coefficient, static friction coefficient and rolling friction factor between seeds (oat seeds and arrow pea seeds) and ABS plastic plate, respectively, and oat and arrow pea seeds were obtained. The collision recovery coefficients with ABS plastic plates were 0.441 and 0.435, the static friction coefficients were 0.506 and 0.454, and the rolling friction coefficients were 0.059 and 0.047, respectively. Based on the stacking test, using the steepest climbing test and quadratic regression orthogonal rotation combination test method, and taking the relative error between the edem simulation value and the actual value of the stacking angle of mixed seeds as the index, the interspecific collision recovery coefficient, static friction coefficient and rolling friction coefficient were determined to be 0.320, 0.327 and 0.042, respectively. The calibration results were verified by the screw seed transmission device. The average relative error of the mixed seed mass flow rate between the simulation test and the actual test was 1.76%, and the average relative error of the seed transmission mass ratio of oat and arrow pea seeds was 2.03%. The reliability of the simulation test was verified. The calibration results can be used in the discrete element simulation test of the mixed sowing process of oat and arrow pea seeds.