In this paper, the problem of landing an unmanned aerial vehicle (UAV) on a platform with unknown oscillating motion is investigated. A control architecture that enables fast, safe and precise landing process is proposed. This control architecture consists of three modules: a tracking control module, a trajectory generation module and a vision-based motion estimation module. For the tracking control module, an Adaptive Robust Controller (ARC) is used to robustly adapt to the changes in thrust due to ground effect. In the trajectory generation module, a time optimal reference trajectory is generated to follow the platform motion. In the motion estimation module, the motion of the moving platform and the UAV is estimated based on only relative distance measurement and acceleration measurement. Comparative simulation and experimental results are presented to validate the effectiveness of the proposed control architecture.
Proceedings of the 71st American Helicopter Society Annual Forum, Virginia Beach, Virginia, May 5–7, 2015.