高速公路上坡路段载重车辆运行速度特性

Operating speed characteristics of heavy vehicle on expressway uphill section

对内蒙古地区高速公路的交通组成、载重车辆功率、载质量、质量功率比进行了统计分析，确定了高速公路上坡路段的主导车型。依据修正的速度预测模型，分别绘制了不同坡度（1％～6％）、坡长、载质量（30、40、50、55t）、质量功率比（80、120、160、200kg·kW^-1）、初始入坡速度（o、20、40、60km·h^-1）下的主导车型运行速度曲线，并从汽车动力学角度研究了曲线变化的原因。分析结果表明：内蒙古地区运煤高速公路主导车型为福田欧曼ETX9系重卡；载重车辆在一定坡道上行驶，当达到平衡速度之后，速度不再随坡长的增加而降低；坡度越大，速度降低越快，最后达到的平衡速度越小；车辆载质量越大，速度降低越快；质量功率比越小，车辆爬坡性能越好；初始速度越高，车辆达到平衡速度所行驶的距离越长。

The traffic composition, heavy vehicle power, load mass and mass-to-power ratio of expressway in Inner Mongolia were analyzed, and the typical vehicle on expressway uphill section was determined. Based on the corrected speed prediction model, the operating speed curves of typical vehicle under different slope gradients（1%-6%）, slope lengths, load masses（a0, 40, 50, 55 t）, mass-to-power ratios（80, 120, 160, 200 kg ·kW^-1） and initial speeds into slope（0, 20, 40, 60 km·h^-1） were drawn, and the reasons of curve changes from vehicle dynamics perspective were studied. Analysis result shows that Foton Auman ETX9 heavy truck is the typical vehicle on the expressway for coal transportation in Inner Mongolia. When heavy vehicle runs on a certain slope, the vehicle speed will not decrease with the increase of slope length after reaching balancing speed. The bigger the slope gradient is, the faster the vehicle speed drops, the lower the final balancing speed is. The bigger the load mass is, the faster the vehicle speed drops. The smaller the mass-to-power ratio is, the better the vehicle climbing performance is. The higher the initial speed is, the longer the distance for vehicle to reach balancing speed is.2 tabs, 11 figs, 11 refs.