A method for determining the safe separation to an unknown-model uncooperative UAV in U-space

Unmanned aerial vehicles (UAVs), often referred to as drones, usher in a new era of aviation by delivering new services at very low-level airspace. Many technical and organisational issues must be addressed to ensure flight safety at the European level. This paper proposes a novel method for addressing the challenge of ensuring a safe minimum separation distance between a conventional drone (CD) and an uncooperative drone (UD) of an unknown model (UDUM). A CD follows regulations and maintains communication with other U-space traffic participants, while a UD conducts a non-conformance flight without permission from the U-space service provider<br/>(USSP), thereby posing a significant threat to flight safety. Our safe separation method relies on a global UAV database analysis and assumes that a vision system or other passive sensing technology (a recognition system) can identify the type of UAV of an unknown model. Additionally, the method involves determining the minimum separation<br/>distance and safety radius of a UDUM using velocity vectors for both the CD and UDUM and performing geometric optimisation. Our UDUM classification led to a significant improvement in measuring the minimum separation distance, resulting in an up to fivefold optimisation among different types of UAVs. We recommend the method for the future autonomous guidance system of CDs.