On the emergence of virtual roundabouts from distributed force/torque-based UAV collision avoidance scheme

Abstract

This paper presents a distributed force/torque-based UAV(Unmanned Aerial Vehicle) collision avoidance scheme. This scheme is designed to deal in a distributed way with the problem of collisions among rotor craft UAVs, that are sharing the space and flying to different destinations. The proposed scheme has a modular architecture, so that it can be easily included into UAVs with a waypoint controller, GPS and communication module. The scheme is though to be simple, in order to make it scalable. It uses a combination of force and torque models for avoiding collisions, while keeping a minimum safety distance. The force model helps to keep a minimum distance among UAVs. The torque model is intended for creating virtual roundabouts, when two or more UAVs simultaneously want to fly over an intersection point. The functionality of the proposed scheme is tested by simulation. The evaluation parameters are overall mission time and the minimum distance keeping to others UAVs while avoiding collision. Scalability, the impact of different maximum speeds and the impact of different values of the parameter “avoidance coefficient” are analyzed. We show that the proposed scheme avoids collisions by the emergence of virtual roundabouts. The roundabout size is self-adaptable according to the number of UAVs. Regarding to the minimum distance among UAVs, we show that the scheme behaves similarly when the number of UAVs increases. However, the mission time increases when more UAVs are involved.