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航拍视频车辆检测目标关联与时空轨迹匹配 被引量:16
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作者 冯汝怡 李志斌 +1 位作者 吴启范 范昌彦 《交通信息与安全》 CSCD 北大核心 2021年第2期61-69,77,共10页
高解析度轨迹数据蕴含丰富车辆行驶与交通流时空信息。为从航拍视频中提取车辆轨迹,构建了车辆检测目标跨帧关联与轨迹匹配融合方法。采用卷积神经网络YOLOv5构建视频全域车辆目标检测,提出车辆动力学与轨迹置信度约束下跨帧目标关联算... 高解析度轨迹数据蕴含丰富车辆行驶与交通流时空信息。为从航拍视频中提取车辆轨迹,构建了车辆检测目标跨帧关联与轨迹匹配融合方法。采用卷积神经网络YOLOv5构建视频全域车辆目标检测,提出车辆动力学与轨迹置信度约束下跨帧目标关联算法,建立了基于最大相关性的断续轨迹匹配与融合构建算法,实现轨迹车辆唯一编号。将轨迹从图像坐标转换为车道基准下Frenet坐标,构建集合经验模态分解(EEMD)模型进行轨迹数据噪声消除。采用南京市快速路无人机拍摄的2组开源航拍视频,涵盖拥堵与自由流交通状态,对轨迹提取算法进行效果测试。结果表明,在自由流和拥挤条件下轨迹准确率分别为98.86%和98.83%,轨迹召回率为93.00%和86.69%,构建算法的轨迹提取速度为0.07 s/辆/m。该方法处理得到的详细车辆时空轨迹信息能为交通流、交通安全、交通管控研究提供广泛的数据支撑,数据公开于http://seutraffic.com/。 展开更多
关键词 车辆轨迹 车辆检测 航拍视频 轨迹构建 轨迹数据
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智能网联车辆低渗透率下交叉口排队长度估计策略
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作者 房山 杨澜 +3 位作者 赵祥模 王威 魏诚 吴国垣 《中国公路学报》 EI CAS CSCD 北大核心 2024年第11期249-261,共13页
为了提高混合交通流条件下信号交叉口的车辆通行效率,提出一种智能网联车辆低渗透率下的信号交叉口车辆排队长度估计策略。首先,根据信号交叉口上游区域车辆的随机到达特性,构建考虑智能网联车辆与人类驾驶车辆组成的车辆排队场景。其次... 为了提高混合交通流条件下信号交叉口的车辆通行效率,提出一种智能网联车辆低渗透率下的信号交叉口车辆排队长度估计策略。首先,根据信号交叉口上游区域车辆的随机到达特性,构建考虑智能网联车辆与人类驾驶车辆组成的车辆排队场景。其次,以智能网联车辆的位移差,速度差以及加速度差为输入,以人类驾驶车辆位移差为输出,建立基于Seq2seq架构的车辆微观轨迹前/后向重构模型,采用时间注意力机制判断车辆行驶状态变化的关键时域,提高模型对车辆“走-停”波的重构能力。再次,以当前信号周期排队车辆数为输入,以车辆排队长度为输出,建立基于XGBoost的车辆排队长度估计模型,可在历史样本数据较少的条件下准确估计车辆排队长度。最后,试验基于NGSIM数据集进行模型训练,在不同智能网联车辆渗透率、单信号周期以及多信号周期等条件下验证所提方法性能。结果表明:在10%~30%的低渗透率条件下,与经典时间序列预测模型RNN、LSTM、Seq2seq以及CNN模型相比,所提出的车辆微观轨迹前/后向重构模型的损失函数收敛速度较快,稳定性更好,车辆轨迹均方根误差降低了8.9%~71.7%,且能够准确描述信号交叉口区域车辆的“走-停”波;相比于基于KNN、随机森林与多项式回归模型的排队长度估计方法,所提方法的均方根误差降低了13.56%~91.99%,排队长度估计的运行时间降低至约8 ms,有效证明了所提方法在交叉口车辆排队长度估计的精确性和实时性。 展开更多
关键词 交通工程 车辆排队长度估计 车辆轨迹重构 数据驱动
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Development and Evaluation of Intersection-Based Turning Movement Counts Framework Using Two Channel LiDAR Sensors
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作者 Ravi Jagirdar Joyoung Lee +2 位作者 Dejan Besenski Min-Wook Kang Chaitanya Pathak 《Journal of Transportation Technologies》 2023年第4期524-544,共21页
This paper presents vehicle localization and tracking methodology to utilize two-channel LiDAR data for turning movement counts. The proposed methodology uniquely integrates a K-means clustering technique, an inverse ... This paper presents vehicle localization and tracking methodology to utilize two-channel LiDAR data for turning movement counts. The proposed methodology uniquely integrates a K-means clustering technique, an inverse sensor model, and a Kalman filter to obtain the final trajectories of an individual vehicle. The objective of applying K-means clustering is to robustly differentiate LiDAR data generated by pedestrians and multiple vehicles to identify their presence in the LiDAR’s field of view (FOV). To localize the detected vehicle, an inverse sensor model was used to calculate the accurate location of the vehicles in the LiDAR’s FOV with a known LiDAR position. A constant velocity model based Kalman filter is defined to utilize the localized vehicle information to construct its trajectory by combining LiDAR data from the consecutive scanning cycles. To test the accuracy of the proposed methodology, the turning movement data was collected from busy intersections located in Newark, NJ. The results show that the proposed method can effectively develop the trajectories of the turning vehicles at the intersections and has an average accuracy of 83.8%. Obtained R-squared value for localizing the vehicles ranges from 0.87 to 0.89. To measure the accuracy of the proposed method, it is compared with previously developed methods that focused on the application of multiple-channel LiDARs. The comparison shows that the proposed methodology utilizes two-channel LiDAR data effectively which has a low resolution of data cluster and can achieve acceptable accuracy compared to multiple-channel LiDARs and therefore can be used as a cost-effective measure for large-scale data collection of smart cities. 展开更多
关键词 vehicle trajectory construction Two Channel LiDAR Turning Movement Counts RTMS Smart Cities LIDAR
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Using Anonymous Connected Vehicle Data to Evaluate Impact of Speed Feedback Displays, Speed Limit Signs and Roadway Features on Interstate Work Zones Speeds
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作者 Jijo K. Mathew Jairaj Desai +1 位作者 Howell Li Darcy M. Bullock 《Journal of Transportation Technologies》 2021年第4期545-560,共16页
Annually, there are over 120,000 crashes in work zones in the United States. High speeds in construction zones are a well-documented risk factor that increases <span style="font-family:Verdana;"><sp... Annually, there are over 120,000 crashes in work zones in the United States. High speeds in construction zones are a well-documented risk factor that increases <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the </span></span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">frequency and severity of crashes. This study used connected vehicle data to evaluate the spatial and temporal impact that regulatory signs, speed feedback displays, and construction site geometry had on vehicle speed. Over 27,000 unique trips over 2 weeks on a 15-mile interstate construction work zone near Lebanon, IN were analyzed. Spatial analysis over a 0.2-mi segment before and after the posted speed limit signs showed that the regulatory signs had no statistical impact on reducing speeds. A before/after analysis was also conducted to study the impact of radar-based speed feedback that displays the motorists</span></span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">’</span></span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> speed on a sign below a regulatory speed limit sign. Results showed a maximum drop in median speeds of approximately 5 mph. Speeds greater than 15 mph above the speed limit dropped by 10%</span></span></span></span></span><span><span><span><span><span style="font-family:;" "=""> </span></span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> 展开更多
关键词 Connected vehicle trajectory Data Speed Limit Compliance Work Zones construction
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定位技术在汽车制造中的应用
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作者 左志军 张永航 《自动化博览》 2019年第2期106-108,共3页
引入定位与万物互联理念、技术,结合智能信息化系统,解决车辆返修业务上述实际问题。提升效率,支持消灭返修的最根本目标逐步实现。从车辆返修业务领域提升企业智慧工厂建设水平,赢得新的竞争力。
关键词 车辆定位 轨迹跟踪 滞留车管理 工时分析 返修要货 智慧工厂建设
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