Dynamic Markers: UAV landing proof of concept

In this paper, we introduce a dynamic fiducial marker which can change its appearance according to the spatio-temporal requirements of the visual perception task of a mobile robot using a camera as sensor. We present a control scheme to dynamically change the appearance of the marker such that the pose of the robot can be optimally estimated from the camera image. The appearance control takes into account the dependency of the estimation quality on the current pose of the camera in relation to the marker. Hence, we realize a tight coupling between the visual pose control of the mobile robot and the appearance control of the dynamic fiducial marker. Further on, we discuss the implications of time delays because of processing time and communication delays between the robot and the marker. Finally, we propose a real time dynamic marker visual servoing control scheme for quadcopter landing and evaluate the performance on a real world example.