Dynamic MAC protocol designed for UAV collision avoidance system

Abstract

During the formation flight of Unmanned Aerial Vehicles (UAVs), avoiding collision with intruders and other UAVs is very important. A key technique of collision avoidance is the real-time delivery of risk related warning messages among UAVs. In UR-MAC, a frame is composed of contention slots and transmission slots. When there is no warning message, each UAV accesses the channel like a TDMA protocol. Otherwise, the warning messages can contend to occupy any already assigned transmission slot. The UAV with higher emergency level has shorter waiting time to claim to occupy the coming transmission slot. Then the other UAVs choose the proper maneuvers to avoid the forthcoming collisions. The simulation results show that the UR-MAC efficiently reduces the delivery latency of warning messages and the collision probability in a UAV formation.