Free LSD: Prior-Free Visual Landing Site Detection for Autonomous Planes
This addresses the need for full autonomy in UAVs for mission completion or emergencies, but it is incremental as it builds on existing methods for hazard assessment and path planning.
The paper tackles the problem of autonomous landing site detection for fixed-wing UAVs in unknown terrain by proposing a perception system that uses texture and geometric shape without prior knowledge, and it was successfully tested in synthetic and real-world environments.
Full autonomy for fixed-wing unmanned aerial vehicles (UAVs) requires the capability to autonomously detect potential landing sites in unknown and unstructured terrain, allowing for self-governed mission completion or handling of emergency situations. In this work, we propose a perception system addressing this challenge by detecting landing sites based on their texture and geometric shape without using any prior knowledge about the environment. The proposed method considers hazards within the landing region such as terrain roughness and slope, surrounding obstacles that obscure the landing approach path, and the local wind field that is estimated by the on-board EKF. The latter enables applicability of the proposed method on small-scale autonomous planes without landing gear. A safe approach path is computed based on the UAV dynamics, expected state estimation and actuator uncertainty, and the on-board computed elevation map. The proposed framework has been successfully tested on photo-realistic synthetic datasets and in challenging real-world environments.