随着排放建模方法从基于行驶周期和平均速度演变为基于VSP(Vehicle Specific Power)参数,利用VSP分布刻画交通状态成为最新的研究需求.近期研究中,针对城市快速路上大于20 km·h-1的速度区间建立了基于平均行程速度的VSP分布数学模...随着排放建模方法从基于行驶周期和平均速度演变为基于VSP(Vehicle Specific Power)参数,利用VSP分布刻画交通状态成为最新的研究需求.近期研究中,针对城市快速路上大于20 km·h-1的速度区间建立了基于平均行程速度的VSP分布数学模型,却未对低速区间的VSP分布特征作深入研究.基于北京快速路大量逐秒浮动车数据,研究0～20 km·h-1的VSP分布与平均行程速度的关系.通过分析大量逐秒浮动数据的VSP分布与平均速度间关系,发现VSP分布与平均行程速度具有规律性:各VSP分布的峰值出现在VSP Bin=0处,且随速度的增加单调递减.因此,针对VSP分布的正、负区间以及VSP Bin=0处分别建立数学模型,并利用该模型进行机动车油耗/排放测算.对比分析油耗/排放的预测值和实测值得出,所建立的VSP分布模型可以有效用于机动车油耗/排放测算.展开更多
Many factors affect the vehicular fuel consumption rate. The most significant traffic-related ones are speed, number of stops, speed noise, and acceleration noise (acceleration standard deviation). Fuel consumption mo...Many factors affect the vehicular fuel consumption rate. The most significant traffic-related ones are speed, number of stops, speed noise, and acceleration noise (acceleration standard deviation). Fuel consumption models for both urban and highway traffic are used to evaluate the effect of these factors. Previous literature shows the speed and the acceleration of vehicles as well as the aerodynamic effects are the most commonly used variables in the highway fuel consumption mo dels. However, most existing models are based on the average or cruising speed and the effect of speed variation is by-and-large ignored. Incorporating the speed noise as a variable in the prediction models seems impractical because measuring it is cumbersome. However, knowing the relation between speed and speed noise may allow including the effect of speed noise in the model indirectly. To that end, this study examines the relation between speed and speed noise. The resulting mathematical relation is used to incorporate the speed noise effects in the fuel consumption model.展开更多
文摘Many factors affect the vehicular fuel consumption rate. The most significant traffic-related ones are speed, number of stops, speed noise, and acceleration noise (acceleration standard deviation). Fuel consumption models for both urban and highway traffic are used to evaluate the effect of these factors. Previous literature shows the speed and the acceleration of vehicles as well as the aerodynamic effects are the most commonly used variables in the highway fuel consumption mo dels. However, most existing models are based on the average or cruising speed and the effect of speed variation is by-and-large ignored. Incorporating the speed noise as a variable in the prediction models seems impractical because measuring it is cumbersome. However, knowing the relation between speed and speed noise may allow including the effect of speed noise in the model indirectly. To that end, this study examines the relation between speed and speed noise. The resulting mathematical relation is used to incorporate the speed noise effects in the fuel consumption model.
