Package Delivery Based on the Leader-Follower Control Paradigm for Multirobot Systems

This paper proposes the adoption of the leader-follower control paradigm as the support to control an unmanned aerial vehicle (UAV), in this case a quadrotor, in the accomplishment of a package-delivery task. The UAV takes-off from a ground vehicle, here an unmanned ground vehicle (UGV) represented by a unicycle robot, goes to the delivery point, over which it stays hovering for a while, and then goes back to the current position of the ground vehicle and lands on it, thus completing the delivery task. In the first step of the delivery task, to go to the delivery point, the delivery drone considers the delivery point as the formation leader, and composes a leader-follower formation with it, suitable to the delivery procedure. After, the delivery drone establishes a leader-follower formation with the ground vehicle, suitable to allow it to land on the ground vehicle. The main difference between these two leader-follower formations is that in the first case the leader is a static one, whereas in the second case the leader is a moving platform. Results of a real experiment, in lab scale, are also shown, which validate the adopted strategy.