Study on Geometry Based Collision Avoidance for Formation Flight by Redefinition of Safety Radius

In this paper, collision avoidance algorithm in a formation flight of multiple UAVs is investigated. The guidance algorithm of the leader-follower concept and the CPA (Closest Point of Approach)-based collision avoidance algorithm for the formation is employed. When the UAVs encounters obstacles during formation flight, if the leader uses the CPA-based collision avoidance algorithm applicable to a single UAV, the safety of the UAVs composing the formation cannot be guaranteed. It is necessary to redefine the safety radius for the entire UAVs in the formation to safely perform collision avoidance. To verify the collision avoidance algorithm by redefining the proposed safety radius, a flight experiments were performed using a PX4-based multicopter.