To study the optimal parameter combinations of grain combine harvesters under different feeding rates, a multi-parameter monitoring system for the cleaning device of grain combine harvesters is designed. Based on this system, an optimization experiment is conducted to study the influence of cleaning device parameters on the impurity rate and loss rate, and regression models for impurity rate and loss rate are established. A comprehensive evaluation index is obtained by setting the weight of impurity rate at 0.4 and loss rate at 0.6. A secondary regression analysis is performed on the data to establish a comprehensive evaluation model. Based on this model, the optimal parameter combinations of the cleaning device under different feeding rates are determined and validated. According to the comprehensive evaluation model, the optimal parameter combination at a feeding rate of 3 kg/s is fan speed of 1 459.8 r/min, a cleaning screen opening of 28.7 mm, and a cleaning screen vibration frequency of 6.5 Hz, resulting in an impurity rate of 1.50%, a loss rate of 0.71%, and a comprehensive evaluation index of 0.203. At a feeding rate of 4 kg/s, the optimal combination is a fan speed of 1 483.4 r/min, a cleaning screen opening of 29.0 mm, and a cleaning screen vibration frequency of 6.9 Hz, leading to an impurity rate of 1.54%, a loss rate of 0.64%, and a comprehensive evaluation index of 0.191. At a feeding rate of 5 kg/s, the optimal combination is a fan speed of 1 587.6 r/min, a cleaning screen opening of 30.0 mm, and a cleaning screen vibration frequency of 7.0 Hz, with an impurity rate of 1.59%, a loss rate of 0.69%, and a comprehensive evaluation index of 0.208. The experimental verification shows that the maximum prediction error for the impurity rate is 7.19%, for the loss rate is 8.43%, and for the comprehensive evaluation index is 12.77%. This indicates that the comprehensive evaluation model is stable and reliable, and can guide the adjustment of the optimal parameter combinations for grain combine harvesters under different feeding rates

为研究谷物联合收获机在不同喂入量下的最优参数组合，设计谷物联合收获机清选装置多参数监控系统。在此系统基础上，开展清选装置参数优化试验，研究清选装置参数对含杂率、损失率的影响规律，得到含杂率、损失率回归模型；取含杂率权重为0.4，损失率权重为0.6，得到各数据的综合评价指标；将各数据进行二次回归分析得到综合评价模型；按照综合评价模型，研究清选装置在不同喂入量下的最优参数组合，并进行验证试验。根据综合评价模型，喂入量x1为3 kg/s，最优参数组合为风机转速1 459.8 r/min，清选筛筛片开度28.7 mm，清选筛振动频率6.5 Hz，此时含杂率为1.50%，损失率为0.71%，综合评价指标为0.203；喂入量x1为4 kg/s条件下，最优参数组合为风机转速1 483.4 r/min，清选筛筛片开度29.0 mm，清选筛振动频率6.9 Hz，此时含杂率为1.54%，损失率为0.64%，综合评价指标为0.191；喂入量x1为5 kg/s条件下，最优参数组合为风机转速1 587.6 r/min，清选筛筛片开度30.0 mm，清选筛振动频率7.0 Hz，此时含杂率为1.59%，损失率为0.69%，综合评价指标为0.208。经试验验证，综合评价模型含杂率预测误差最大为7.19%，损失率预测误差最大为8.43%，综合评价指标预测误差最大为12.77%，表明综合评价模型稳定可靠，可以用于指导谷物联合收获机在不同喂入量下调整最优参数组合。