一种车速截断对数正态分布的车队离散模型

Platoon dispersion model based on truncated lognormal distribution of speed

针对现有Pacey模型不能较好解决车速服从偏性正态分布的缺陷,假设车速服从最小速度至最大速度区间上的截断对数正态分布,提出了一种车速截断对数正态分布的车队离散模型.以上游交叉口的排队车辆在绿灯放行后的时空分布特征为研究对象,从交通流密度的角度出发,分析这部分车辆的车速统计特征对其下游道路上行驶离散过程的影响,并给出车队密度等交通流参数的计算公式.在此基础上,推导了车队头、尾部的离散模型,为下游交叉口的配时方案提供交通数据.最后,以某相邻交叉口的协调控制为例,比较所提模型与现有Pacey模型在计算交通流参数方面存在的差异.数值仿真结果表明,前者在优化信号灯配时方案中需要较少的提前和后延时间.

To solve the shortcomings that the Pacey＇s platoon dispersion model cannot well reflect partial normal distribution in the field situation, a platoon dispersion model based on a truncated lognormal distribution is presented by assuming that the speed follows the truncated lognormal distribution ranging from the minimum to the maximum. The research objects are the temporal and spatial distribution characteristics of queuing vehicles at the upstream intersection after the platoon moves from an upstream at green phase end time. From the density view, the effect of the speed statistical characteristics of these vehicles on the spread of cars along the downstream road is analyzed, and some formulas for calculating traffic flow parameters such as platoon density are presented. Then, the dispersion models of the front and the rear of the platoon are derived to provide traffic data for signal timing plans of the downstream intersection. Finally, by taking the coordination of successive signals for example, the computing traffic flow parameters of the proposed model are compared with those of the Pacey＇s platoon dispersion model. The results of numerical simulation show that the former has less advanced and delayed time in optimizing signal timing plans.