Abstract: The driving resistance coefficient is a key input for the simulation of automotive performance and economy, engine matching, and fuel consumption emission testing. It runs through the entire process of automotive development. In order to accurately obtain the driving resistance coefficient before the actual vehicle coasting test, this article analyzes the motion model of the vehicle during coasting motion, establishes the relationship between the driving resistance coefficient and the tyre rolling resistance, transmission system resistance and air resistance. Combined with the existing test data of mass production vehicle, a method is proposed to establish a driving resistance family based on the transmission type, interpolate and calculate the driving resistance coefficient of newly developed vehicle models, and meet the requirements of vehicle development for driving resistance coefficient before actual vehicle coasting. After mass production of the actual vehicle, coasting test is conducted in the testing field, and the test results verified the effectiveness of the method.

Key words: driving resistance coefficient; interpolation; calculation method; cyclic energy demand;transmission system resistance; driving resistance family

摘要： 行驶阻力系数是汽车动力性经济性仿真、发动机匹配和油耗排放试验的关键输入，贯 穿汽车开发的整个过程。为了在实车滑行试验前获得准确的行驶阻力系数，文章通过分析整 车滑行运动时的运动模型，建立行驶阻力系数与轮胎滚动阻力、传动系阻力和空气阻力之间 的关系，再结合基础量产车型已有的试验数据，提出了一种依据变速箱类型建立行驶阻力系 族，插值计算新开发车型行驶阻力系数的方法，满足了实车滑行前整车开发对行驶阻力系数 的需求。实车量产后，在试验场进行实车滑行试验，试验结果验证了该方法的有效性。

关键词: 行驶阻力系数；插值；计算方法；循环能量需求；传动系阻力；行驶阻力系族