基于神经网络的行驶时长预测

Research on travel time prediction based on neural network

定位设备的普及产生了海量的车辆行驶数据,使得利用历史数据预测车辆行驶时长成为可能.车辆行驶数据由两部分组成:车辆行驶经过的路段序列信息和出发时段;路径总长度等外部信息.如何提取路段序列特征,以及如何将序列特征与外部特征有效地融合,成为预测行驶时间的关键问题.为解决以上问题,提出了一个基于Transformer的行驶时间预测模型,模型由路段序列处理模块和特征融合模块两部分组成.首先,路段序列处理模块使用自注意力机制处理路段序列,提取路段序列特征.该模型不但可以充分考虑各条路段与其他路段间道路速度的时空关联性,同时可保证数据并行输入模型,避免了使用循环神经网络时数据顺序输入导致的效率低下.其次,特征融合模块将路段序列特征与出发时段等外部信息相融合,最终获得预测的行驶时长.在此基础上,统计路口连接的路段数作为路段的上/下游路口特征,与路段特征结合输入模型,进一步提升了行驶时长的预测精度.在真实的数据集上与主流预测模型进行的对比实验表明,该模型在预测精度以及训练速度上均有提升,体现了所提模型的有效性.

The popularity of positioning devices has generated a large volume of vehicle driving data,making it possible to use historical data to predict the driving time of vehicles. Vehicle driving data consists of two parts: the sequence of road segments that the vehicle travels through, the departure time,the total length of the path, and other external information. The questions of how to extract sequence features in road segments and how to effectively fuse sequence features with external features become the key issues in predicting the travel time. To solve the aforementioned problems, a transformer-based travel time prediction model is proposed, which consists of two parts: a road segment sequence processing module and a feature fusion module. First, the road segment sequence processing module uses the self-attention mechanism to process the road segment sequence and extract the road segment sequence features. The model can not only fully consider the spatiotemporal correlation of road speeds between each road segment and other road segments, but also ensures the parallel input of data into the model, avoiding the low efficiency problem caused by sequential input of data when using recurrent neural networks. The feature fusion module fuses the road segment sequence features with external information, such as departure time,and obtains the predicted travel time. On this basis, the number of road segments connected by the intersection is determined by the upstream and downstream intersection features of the road segment, and the input model is combined with the road segment characteristics to further improve the prediction accuracy of the driving time. Comparative experiments with mainstream prediction methods on real data sets show that the model improves prediction accuracy and training speed, reflecting the effectiveness of the proposed method.