Waypoint Navigation in the Image Plane for Autonomous Navigation of UAV in Vision-Based UAV-AGV System*

Vision-based UAV-AGV collaborative system is one of the popular collaborative robotic systems which is advantageous in GPS (Global Positioning System) inaccessible areas for various applications. Inspection, surveillance, target tracking and environment mapping are the potential applications of the system. UAV can assist the navigation of AGV and AGV can support the long range missions of UAV. UAV carries a down facing camera for the relative localization of AGV. This configuration is the most popular vision-based UAV-AGV system. Collaborative motion between both agents is an important aspect of the system to perform any task. An image plane based autonomous waypoint navigation technique for the collaborative motion of UAV is developed in this paper. The collaborative task of UAV is to visit the various target positions in the image plane (while keeping AGV in field of view (FOV)) to gain the knowledge of the surroundings of AGV or to perform inspection at the target positions. Each target position is a waypoint to be reached by the UAV in the image plane. UAV plans minimum acceleration trajectories connecting each target location and reaches one by one. A sliding mode theory based novel kinematic controller is designed for tracking of the designed trajectories. The proposed method is validated in the Gazebo simulation tool. The method is useful in GPS denied environments for the UAV to plan smooth navigation to visit multiple positions in the image plane. UAV can reach various positions in sequence in the image plane to increase the knowledge of the environment. The method is also useful to perform discrete inspection of the horizontal infrastructures which are not reachable to AGV during collaborative inspection task.