A Vision-based Automatic Landing System for Fixed-wing UAVs using an Inflated Airbag

We present a vision-based landing system for fixed-wing unmanned aerial vehicles (UAVs) using an inflated airbag. As the statistics show, the landing stage is identified as most accident-prone among the entire flight regimes due to the complicated dynamics, difficult control characteristics and its dependency on many external factors such as wind conditions. Therefore there have been many attempts to automate the landing process on conventional runways or external arresting mechanisms such as ropes or nets. In this paper, we propose a relatively simple yet highly effective vision-based landing method using an inflatable airbag. Its distinctive color provides unmistakably strong yet passive visual cue for the onboard vision system, which runs a fast and robust color tracking algorithm for geolocation and visual servoing. The airbag has a dome shape so that the airplane can approach from any direction, unlike the net-based approach that may suffer from crosswind. The proposed idea has been validated in a series of experiments using a blended wing-body (BWB) UAV testbed. Experiment results show that the proposed method is a viable approach for field applications without the need of expensive aiding systems. I. Introduction