A flight risk field model for advanced low-altitude transportation system using field theory

Traffic congestion, as a global issue, often leads to adverse social impacts and huge economic losses, especially in urban areas. Utilizing the available urban low-altitude airspace (ULA) is a potential and promising solution to this problem. To fully leveraging ULA and establishing an advanced low-altitude transportation (ALT) system, ensuring the safety of low-altitude flight is of critical importance. However, the ALT system is currently in the exploratory and developmental stage, and the assessment of flight safety relies primarily on pre-flight evaluations and third-party risk indicators. This study introduces a novel flight risk field model considering risk factors during UAV cruising by introducing a new concept of a flight risk field. The model takes into account the key factors influencing the safety of low-altitude flights, considering both the static characteristics of buildings and the dynamic movements of unmanned aerial vehicles (UAVs). It is capable of reflecting the spatiotemporal variations in flight risks during the UAV cruising process. Finally, the model is validated through numerical examples and simulations. The contribution of this paper is to provide a new idea and method for the safety assessment of the ALT system, which can be further applied to airspace structure design, route optimization, and constitution of traffic regulations, to ensure a reasonable airspace design and enhance the safety of low-altitude flight activities.