HArCo: Hierarchical Fiducial Markers for Pose Estimation in Helicopter Landing Tasks

A reliable pose estimation is crucial in the landing tasks of helicopters. This paper mainly focuses on presenting a smooth and reliable pose estimation method during helicopter landing using Augmented Reality (AR) markers. Based on the proposed hierarchical fiducial marker system called Hierarchical Augmented Reality Code (HArCo), pose estimation can be performed within a much longer range. The design of the system, generation of the marker dictionary and the application in helicopter landing are thoroughly described in this paper. The performance of the pose estimation algorithm based on HArCo is tested in a landing task. As pose information is accessible throughout the landing procedure, a safe auto-landing based on HArCo can also be conducted.