We develop highly advanced methods for In-Flight Conflict Detection and Resolution (CDR), which is an important element of the Core UTM.

We model conflict resolution as an optimization problem. Our method ensures:

• Conflict-free paths, i.e., no collisions
• Minimally evasive trajectories for all UAVs in case of conflict
• Equal share in evasive behaviors for all UAVs (except for emergency case)

We use centralised and distributed algorithm-based collision avoidance methods. Specifically, we are testing variations of ORCA (Optimal Reciprocal Collision Avoidance).