Improving Conflict Prevention in Constrained Very Low-Level Urban Airspace, U-Space

Abstract

The rate of urbanization is expected to continue increasing. This has led to an interest in using drones and air taxis for urban transportation in place of the current methods, which often lead to road congestion. In most places urban air operations will happen above buildings. However, in many cities with large skyscrapers it may not be efficient to fly above buildings as it would add travel distance. For these cases, aircraft will have to operate in constrained airspace (above roads and between buildings). There is still a knowledge gap for operating in constrained very low-level urban airspace. Most studies attempt to improve the safety in constrained airspace with strategic or tactical conflict resolution. But this may not be enough to ensure safety in highly-dense urban environments. The restriction of heading manoeuvres by buildings substantially limits the solution space for conflict resolution. Therefore, conflict prevention with airspace design can be an important tool for improving airspace safety. In a layered airspace, turn layers can be used so that turning aircraft do not create bottlenecks for cruising aircraft that may be behind it. However, merging conflicts can occur when these turning aircraft attempt to re-enter cruising layers. These are typical in both orthogonal (New York) and non-orthogonal (Paris) street networks. Non-orthogonal street networks can also create merging conflicts because it is not always possible to segment cruising aircraft at intersections. This work will propose two conflict prevention doctoral research experiments that aim to reduce merging conflicts. The first will use three different layering techniques to reduce merging conflicts created by turn layers. The second will focus on merging conflicts that are typical of non-orthogonal networks.