This paper develops a high-density air corridor traffic flow model for Uncrewed Aircraft System (UAS) operation in urban low altitude airspace. To maximize throughput with safe separation guarantees, we define an airspace spatiotemporal planning problem. For the spatial planning, we propose a multi-floor UAS coordination structure divided into a finite number of air corridors safely wrapping buildings and obstacles. We use the USGS Lidar data to map buildings and in turn generate air corridors by modeling UAS coordination as ideal fluid flow with the streamlines obtained by solving the Laplace partial differential equation (PDE). Proper boundary conditions for the differential equations are imposed to direct air corridors along the floors desired motion direction. For temporal planning, we use 4-dimensional path-finding through the corridor network with A* search to maximize airspace usability given each UAS initial and destination waypoint pair.

翻译：本文针对城市低空空域中无人航空器系统（UAS）的运行问题，提出了一种高密度空中走廊交通流模型。为确保安全间隔条件下的最大吞吐量，我们定义了一个空域时空规划问题。在空间规划方面，我们提出了一种多层UAS协调结构，该结构将空域划分为有限数量的空中走廊，以安全地绕开建筑物与障碍物。我们利用美国地质调查局（USGS）的激光雷达（Lidar）数据对建筑物进行建模，进而通过将UAS协调建模为理想流体流动，并求解拉普拉斯偏微分方程（PDE）获得流线，从而生成空中走廊。通过为微分方程施加适当的边界条件，引导空中走廊沿各层期望的运动方向延伸。在时间规划方面，我们采用基于A*搜索的空中走廊网络四维路径规划方法，根据每架UAS的起点与终点航点对，最大化空域可用性。