A 2.5D Risk-Aware Path Planning Method for Safe UAS Operations in Populated Environments

The increasing use of Unmanned Aircraft Systems (UAS) in Urban Air Mobility highlights the critical need to create safe urban air corridors. In this paper, we present a novel 2.5D risk-aware path planning strategy with the aim of computing safe routes for UAS in urban areas. The proposed approach uses 2.5D risk maps to assess the risk to the population on the ground caused by UAS operations. Specifically, the 2.5D risk map consists of a multi-layer structure discretizing the flight altitude and providing a simplified representation of the three-dimensional space. Thus, a 2.5D risk-aware path planning searches for the minimum risk path in the 2.5D risk map. The adopted risk-aware path planning is based on the well-known RRT* algorithm with the minimization of the overall risk in the risk map and the flight time. Furthermore, an energy-aware factor is also included in the cost function to obtain a more energy-efficient solution, avoiding excessive changes in altitude. The simulation results obtained considering a real-world scenario corroborate the proposed strategy. The combined use of 2.5D risk maps with a risk-aware path planning algorithm provides a promising solution for computing safe and energy-efficient routes in urban areas.