项目名称: 数据稀疏和数据缺失情况下的旅行时间预测研究
项目编号: No.51278280
项目类型: 面上项目
立项/批准年度: 2013
项目学科: 建筑科学
项目作者: 李力
作者单位: 清华大学
项目金额: 82万元
中文摘要: 近年来,国内城市道路旅行时间预测研究遇到了许多新的挑战,其中包括: 1)数据稀疏的问题。国外已有研究往往假定能够检测到一段时间内通过某一路段的大多数车辆的旅行时间。但我国各城市的智能交通系统均在完善中,能检测的车辆比例经常较低。 2)数据缺失的问题。由于传感器和数据传输网络的物理条件所限,目前国内外的智能交通系统均存在数据缺失问题。而国内很多城市的数据缺失情况更为严重。 3)历史数据不足,影响预测模型辨识校正的问题。 有鉴于此,本项目将城市道路个体车辆旅行时间和整体交通流运动规律研究有机结合在一起,着力发展基于贝叶斯网络的旅行时间预测模型。我们将数据稀疏、数据缺失和小样本转化为特定结构的后验知识,统一考察后验知识结构和数量的变化对于贝叶斯推理结果的影响,最终改进目前的旅行时间预测算法。相关结果可用于匝道控制等多方面,具有重要的学术意义和广阔的应用前景。
中文关键词: 旅行时间预测;数据稀疏;数据缺失;;
英文摘要: Recently, many new problems are emerging and challenging researchers in urban travel time prediction field. These problems include: 1) Sparse data problem. Most recent studies assume we can collect the travel time data of most vehicles that had passed through a certain road segment in a certain time period. However, all the intelligent transportation systems in Chinese cities are still under constructing, and we can only detect and record a few vehicles. The collected travel time data are thus sparse. 2) Missing data problem. Because of the physical limits of sensors and data transmission networks, intelligent transportation systems around the world are suffering from missing data problem. In many Chinese cities, the missing ratios are often higher than usual. Many previous travel time prediction models cannot give satisfactory results by using the data with such high missing ratios. 3) Small sample size problem. Since the intelligent transportation systems in many Chinese cities are under developing, we do not always have a large amount of historical travel time data available. This usually leads to inappropriate identification and training of forecasting models. Considering these three problems, we aim to integrate the research on individual vehicle 's travel time and the research on overall tr
英文关键词: Travel Time Prediction;Sparse Data;Missing Data;;