Collision avoidance of multi unmanned aerial vehicles: A review

The control of a multiple unmanned aerial vehicle (UAV) system is popular and attracting a lot of attentions. This is motivated by many practical civil and commercial UAV applications. Collision avoidance is the fundamental in motion planning of multi-UAVs, especially for large teams of UAVs. Although several collision avoidance approaches have been reported, there is a lack of highlighting the key components shared by these approaches. In this work, we aim to provide researchers with a state-of-the-art overview of various approaches for multi-UAV collision avoidance. The existing works on collision avoidance are presented through several classifications based on algorithm used and frameworks designed, and their main features are also discussed. A discussion on the literature summary in multi-UAV collision avoidance is given, Finally, the challenges in the research directions are presented.