Assessment of Tracking Small UAS Using IR Based Laser and Monocular-Vision Pose Estimation

Global Navigation Satellite System (GNSS) is a widely available tracking solution from aircraft to smartphones. Small Unmanned Aerial Vehicles (sUAVs) are also heavily dependent on GNSS to fly autonomously from location to location. However, sUAVs have limited battery life and most sUAVs change batteries and pick up cargo manually by human operators. However, GNSS is insufficient when sUAVs are used in large quantities for patrol, delivery, and construction were picking up various payloads and changing batteries are frequently required. GNSS is sufficient for taking the sUAVs from point A to point B in open air space with communication to the satellites. If the fully autonomous operation were to only rely on GNSS navigation, the landing hubs would be limited to open spaces such as rooftops or parking lots. Commercial grade GNSS receivers also have limited update rates of 1-10Hz, limiting the capability of the landing sUAV. The purpose of this project is to investigate tracking methods available for supplementing the existing GNSS solution that will assist the sUAVs in landing at more flexible locations. Methods include: 1) ground-based IR LED array markings identified by a monocular camera onboard the sUAV, and 2) IR laser sweeping identified by IR photodiodes onboard the sUAV. Each of these methods is capable of localizing the sUAVs at rates of 15Hz to 120Hz without location limitations such as using GNSS. These methods can expand the landing capability of the sUAVs to confined spaces such as warehouses and building floors under construction, or mobile locations such as delivery trucks and patrol cars, even landing/docking for aerial vehicles on Mars. The scope of this paper includes implementation and assessment of SteamVR tracking and IR marker-based monocular-vision pose estimation on sUAV platforms to perform two types of maneuvers, a continuous circular flight path and a flight path based on stop-and-go waypoints. Findings suggested that Lighthouse can achieve high accuracy and tracking fidelity in an ideal environment, but subject to interference from large reflective surfaces. The IR marker-based pose estimation can achieve centimeter accuracy in ideal conditions but largely limited by its hardware specifications.