Bearing Sensor for 3D Localization and Swarm Centroid Detection

A bearing sensor measures its orientation relative to a landmark. Such sensors enable tracking and localization. Since small Unmanned Aerial Vehicles (UAVs) suffer from payload limitations, they must be equipped with lightweight sensors with low power consumption. This paper presents two implementations for bearing sensors. First, a novel vision-based sensor based on a camera and a spherical mirror that enables wide view. This sensor is lightweight and low cost (20 [g] and under 8 [USD]). Second, a novel, laser-based beacon together with a photo-diode based sensor which enables to better distinguish between multiple landmarks while keeping inclination mismatch robustness. We present the scheme for detecting the relative angular position of an aerial agent to a light-based landmark in 3D. We also present algorithms for the localization of a UAV, and swarm centroid detection, both using such bearing observations. Finally, we demonstrate our sensors and algorithms in real-world experiments and provide their accuracy.