Docking Interface for Aerial-Ground Robot Collaboration: Design and Implementation of an Autonomous Coupling System

With the rapid advancement in technology, robotic systems have become increasingly popular and are used to aid in various complex tasks requiring automation. Although UAV and UGV systems have many individual applications, their cooperation has also proven to be of great value to the industry and the scientific community as a whole. The purpose of this research is to develop a coupling system between a UAV and a UGV so that the drone can land and recharge on the rover. The coupling system is composed of mechanical and electrical interfaces, which aim to correct the drone's landing errors caused by dynamic and environmental uncertainty and recharge the drone's battery. Initially, a study was carried out to analyze the state of the art of UGV and UAV collaboration. From this analysis, the best trade-off design was chosen, which consisted of a docking station that corrects the drone's landing errors through gravity and two electrodes placed on the base of the station for the recharging of the drone. Then, CAD prototypes were developed in SolidWorks, which were later imported into Gazebo to simulate the landing in a realistic environment with PX4-Autopilot running on the drone's model. The landing was done autonomously by means of a ROS2 node that uses the OpenCV library and a downward-facing camera to acquire an ArUco marker. An error analysis was then carried out to consider how the design would perform in sub-optimal conditions, such as with higher errors in the sensor measurements and with different sizes of the fiducial marker. Lastly, a final prototype was obtained by 3D printing the design.