Comprehensive Risk Modeling, Assessment, and Mitigation Method for Urban Air Mobility

As urban air mobility (UAM) continues to grow, the risks associated with unmanned aircraft systems (UAS), which are among the key participants in future UAM operations, will inevitably increase. These risks include potential impacts on people and vehicles on the ground and the possibility of collisions with manned aircraft near airport airspace. It is essential that such risk is mitigated before any flight is executed. In this paper, we present a comprehensive risk modelling, assessment, and mitigation method for UAS operations. First, we model three types of risk (i.e. pedestrian, vehicle, and manned aircraft) and quantify the cost of risk to build a risk cost map. Then, we generate the map around the high-risk areas of the flight segments and propose a risk-based A* algorithm for targeted re-planning of the original flight path. Finally, a trajectory prediction model is used to further optimise the path taking into account the performance of the specific UAS. Future mission scenarios have been simulated to validate our proposed method. Results suggest that the optimised solution can effectively mitigate the risk by means of avoiding densely populated ground areas and airport airspace for instance, ensuring precise trajectory following and significantly reducing the potential risk associated with the original flight plan.