Abstract:  Because of the variety of highland barley and the difficulty of direct measurement of part of the contact parameters, this study takes the angle of repose of highland barley as the target value to simulate and calibrate the contact parameters of highland barley. The response surface method was used. Eight discrete element simulation parameters of highland barley were screened through the PlackettBurman test. Three factors that had significant influences on the angle of repose of highland barley were obtained, which were the static friction coefficient of highland barley, the rolling friction coefficient of highland barley, and the static friction coefficient of ‘highland barleypla plate’. Through the steepest climbing test, the optimal range of three significant factors was determined. Based on the BoxBehnken test, the secondorder regression model of the angle of repose and significance parameters was established, and the equation was optimized. The optimal parameters of significance parameters were 0.19, 0.01, and 0.43. Finally, the simulation test was carried out. The results showed that the error between the angle of repose obtained from the simulation test and the actual angle of repose was 064%. The small error indicated that the simulation calibration parameters were feasible, and can provide a reference for the future research of highland barley seeder.

Key words: highland barley, EDEM, response surface methodology, angle of repose, contact parameter, parameter calibration

摘要： 针对青稞品种多样,且部分接触参数难以直接测量的问题,本研究以青稞的休止角为响应值,对青稞的接触参数进行标定。采用响应面法:通过Plackett-Burman试验对青稞的8个离散元仿真参数进行筛选,得到对青稞休止角有显著性影响的三个因素:青稞—青稞的静摩擦系数、青稞—青稞的滚动摩擦系数、青稞—pla平板的静摩擦因数;通过最陡爬坡试验确定三个显著因素的最优取值范围;在此基础上进行Box-Behnken试验,建立休止角与显著性参数的二阶回归模型,并对方程进行优化,求得显著性参数的最优参数值:青稞—青稞的静摩擦系数0.19、青稞—青稞的滚动摩擦系数0.01、青稞与pla平板的静摩擦因数0.43。最后进行仿真验证试验,结果表明仿真试验所得休止角与实际休止角值误差为0.64%,误差很小表明仿真标定的参数是可信的,可以为今后的青稞排种器的研究提供参考。

关键词: 青稞, EDEM, 响应面法, 休止角, 接触参数, 仿真标定