基于最小浮动车样本数量的道路覆盖率与交通信息更新周期研究

基于浮动车样本数量的道路覆盖率与交通信息更新周期的关系是浮动车信息采集技术应用中亟待解决的关键问题。浮动车的道路覆盖率与交通信息更新周期之间成正比关系,通过对基于经典概率统计理论的传统计算最小浮动车样本数量方法中所存在不足的分析,提出从路段内车辆运行时间角度出发考虑样本量,引入表征运行时间变化的变量,确定满足道路覆盖率的最小浮动车样本数量,进而建立基于浮动车样本数量的道路覆盖率与交通信息更新周期的关系模型,并给出满足道路覆盖率的浮动车最小样本数量计算的改进算法。通过成渝高速公路成都—龙泉段的实际浮动车数据,验证了关系模型的可靠性及改进算法的优越性。

Study on the Route Coverage and the Update Cycle of Transportation Information Based on the Minimum Samples of Floating Car

The relationship between the route coverage and the update cycle of transportation information based on the minimum samples of floating car is the key problem to be urgently solved in the information acquisition technology of floating car.The route coverage of floating car is in direct proportion with the update cycle of transportation information.This paper analyzes the deficiencies for calculating the minimum samples of floating car existed in traditional algorithm based on classical probability theory.It proposes that the number of samples be considered in terms of vehicle running time in the section of a highway.It introduces a variable indicating the variations of running time to determine the minimum samples of floating car,which can meet the requirement of route coverage.Then the relational model of the route coverage and the update cycle of transportation information based on the number of floating car samples is established and an improved algorithm is presented for calculating the minimum samples of floating car,which can satisfy the route coverage.Finally the reliability of the relational model and the superiority of the improved algorithm have been validated by the practical data obtained from Chengdu to Longquan section of Chengyu expressway.