A vision-based landing system for small unmanned aerial vehicles using an airbag

Statistics show that the landing accounts for the largest portion of all mishaps of unmanned aerial vehicles (UAVs) due to many difficulties including limited situational awareness of the external pilot and the limited maneuverability during the low speed flight before touchdown. In this paper, a vision-based automatic landing system using a dome-shaped airbag is proposed for small UAVs. Its isotropic shape allows airplanes to approach in any direction to avoid crosswind unlike net-assisted landing. The dome’s distinctive color improves the detection owing to its strong visual cue. Color- and shape-based detection vision algorithms are applied for robust detection under varying lighting conditions. Due to the insufficient accuracy of navigation sensors, a direct visual servoing is used for terminal guidance. The proposed algorithm is validated in a series of flight tests.