标题： 拥堵中的交通状态估计以扩展DFOS的适用性 显示英文标题

标题： Traffic State Estimation in Congestion to Extend Applicability of DFOS

摘要： 本文提出了一种在拥堵情况下的交通状态估计（TSE）方法，用于分布式光纤传感（DFOS）。 DFOS检测沿光缆的车辆行驶振动，并在时空平面上获得其轨迹。 从这些轨迹中，DFOS提供了平均速度，用于实时的空间连续交通监测，没有盲区。 然而，当车辆振动强度由于速度过慢而不足时，无法获得轨迹，导致平均速度数据中出现缺失值。 这限制了DFOS在严重拥堵中的适用性。 因此，本文提出了一种基于数据同化的缺失值填补方法。 我们提出的这种方法在日本两条高速公路上的参考数据进行了验证。 结果表明，与非缺失值的MAE相比，填补后的平均速度与参考值的平均绝对误差（MAE）仅增加了1.5 km/h。 本研究提高了DFOS在实际案例中的广泛应用性。 显示英文摘要

摘要： This paper presents a traffic state estimation (TSE) method in congestion for distributed fiber-optic sensing (DFOS). DFOS detects vehicle driving vibrations along the optical fiber and obtains their trajectories in the spatiotemporal plane. From these trajectories, DFOS provides mean velocities for real-time spatially continuous traffic monitoring without dead zones. However, when vehicle vibration intensities are insufficiently low due to slow speed, trajectories cannot be obtained, leading to missing values in mean velocity data. It restricts DFOS applicability in severe congestion. Therefore, this paper proposes a missing value imputation method based on data assimilation. Our proposed method is validated on two expressways in Japan with the reference data. The results show that the mean absolute error (MAE) of the imputed mean velocities to the reference increases only by 1.5 km/h as compared with the MAE of non-missing values. This study enhances the wide-range applicability of DFOS in practical cases.