UVDAR System for Visual Relative Localization With Application to Leader–Follower Formations of Multirotor UAVs

A novel onboard relative localization method, based on ultraviolet light, used for real-time control of a leader-follower formation of multirotor UAVs, is presented in this paper. A new smart sensor, UVDAR, is employed in an innovative way, which does not require communication and is extremely reliable in real-world conditions. This innovative sensing system exploits UV spectrum and provides relative position and yaw measurements independently of environment conditions such as changing illumination and the presence of undesirable light sources and their reflections. The proposed approach exploits this retrieved information to steer the follower to a given three-dimensional position and orientation relative to the leader, which may be considered as the main building block of any multi-UAV system operating with small mutual distances among team members. The proposed solution was verified in demanding outdoor conditions, validating the usage of UVDAR in real flight scenario, and paving the way for further usage of UVDAR for practical multi-UAV formation deployments.