Design of an Automatic Item Pick-up System for Unmanned Aerial Vehicles

Abstract

The interest of Unmanned Aerial Vehicles (UAVs) for the purpose of package delivery has increasedsignificantly in recent years. However, the abilities of those vehicles are quite limited since the armshave not being designed considering the UAV geometry and the center of gravity (CG) changes. Usualapproach taken by various researchers were to use a regular gripper or a robotic manipulator, which isnot quite satisfactory for access. In this paper, a novel arm mechanism has been proposed to accessobjects near and under the UAV without risking any collision, with little rotor wash on objects and littlechange of UAV CG while enabling grip of variable shaped objects. The mechanism is based on a doublefour-bar linkage. Moreover, the gripper and the mechanism enable access to objects from locationsbelow as well as next to UAV. With the help of the onboard controller and camera, the arm acts as anindependent entity to identify the position of the part, catch it, and autonomously hold it. It is alsopossible to carry more than one object within the storage area. A flexible three-finger gripper has beendesigned to hold several different geometric shaped objects. The proposed arm and gripper designed,manufactured and installed on a UAV. Initial tests verify that it can identify and catch spherical,cylindrical, and box shaped pieces weighting up to 650 grams.