基于航模辅助观测的车辆轨迹提取方法

Vehicle trajectory extraction based on traffic videotaping from model aircraft

为了克服交通流定点视频观测方法在观测范围上的局限性,提出了一种基于飞行航模辅助视频观测的地面道路车辆轨迹提取方法.首先应用飞行航模在空中拍摄获得道路交通流视频,并将视频分解为连续逐帧图片;其次应用针孔成像模型和空间坐标转换算法,对逐帧航拍图片内的车辆坐标进行提取和转换,以获得车辆的运行时空轨迹数据;最后进行了该方法的3类误差分析.结果表明,该方法在标准棋盘格试验下提取坐标的相对误差小于5%,实际道路交通目标坐标提取的精度达到90%以上.航模辅助视频观测法可实现对交通目标的大范围低成本观测,能够满足交通工程的观测需求.

To overcome the scope limitation of video observation from fixed platforms, a new method of detecting vehicular trajectory from the traffic flow video provided by model aircraft is proposed. First, model aircraft shoots the traffic flow in the air to get the video which is consequently extracted into continuous frames. Second, by using the pinhole camera model and the algorithm of space coordinate transformation, the coordinates of vehicles from the continuous frames are obtained to form the spatial temporal trajectory of vehicles. Finally, three kinds of bias of the proposed method are analyzed. The results show that the relative bias in the standard checkerboard testing is less than 5%, and the accuracy of the data collected by the system under the real road is greater than 90%. The proposed approach provides a large scope and low-cost way for traffic observation, which can meet the demand of survey in transportation engineering.