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

The interest of Unmanned Aerial Vehicles (UAVs) for the purpose of delivery has increased significantly in recent years. However, the abilities of those vehicles are quite limited since the arms have not being designed considering the UAV geometry and the center of gravity (CG) changes. Usual approach taken by various researchers were to use a regular gripper or a robotic manipulator, which is not quite satisfactory for access. In this paper, the design of a mechanism for the purpose of catching and holding various shaped objects is proposed. The mechanism, which is based on a double four-bar mechanism, has been designed for minimum CG change. Moreover, the mechanism has the ability to grap objects from locations below as well as next to UAV. Besides, with the help of the onboard controller and camera, the arm acts as an independent entity to identify the position of the part, catch it, and autonomously hold it. It is also possible to carry more than one object with a net structure inside the mechanism storage area. The gripper has been designed and manufactured with flexible parts so that it can hold several geometric shaped objects. The UAV-arm has been designed and manufactured. It is installed on a UAV. Initial tests verify that it can identify and catch spherical, cylindrical, and box shaped pieces up to 650 grams.