Conference Paper

The coordinated operation of multiple Unmanned Aerial Vehicles (UAVs) in shared airspace introduces significant challenges related to collision avoidance, particularly in swarm based and mission-oriented deployments where aircraft operate in close proximity. This work presents proactive and reactive collaborative strategies for collision avoidance based on Global Navigation Satellite System (GNSS) data within an existing fleet
management platform. By extending the platform to enable mesh-based inter-UAV telemetry exchange, each vehicle is provided with a local autonomy layer capable of enforcing safety measures while mission execution remains centrally coordinated. A reactive circumvention manoeuvre is introduced as a lastresort mechanism to handle imminent collision risks through safety zones defined around each drone, while a proactive path planning approach computes collision-free waypoint sequences by treating neighbouring UAVs as obstacles in a grid-based representation of the environment. The proposed mechanisms were evaluated through simulation, and the proactive strategy was
further validated in real-world experiments using hexacopter UAVs. Results demonstrate the effectiveness of the approach in maintaining safe inter-vehicle separation and achieving collision free navigation in scenarios in the presence of stationary neighbouring
aircraft.