Design and Flight Testing of a UAV with a Robotic Arm

Unmanned Aerial Vehicles (UAVs) also commonly known as drones, are increasingly being used in many industries as they capable of accessing areas that are difficult to reach or are remote. However, due to limitations in the payload's reachability the same level work that a human in a similar location cannot be completed. To address this issue, this paper presents the implementation of a robotic manipulator on a UAV which can extend the reachability beyond the normal constraints of the UAV. Many designs of robotic manipulators underneath the UA V have been previously proposed. However, limited designs explore the use of a manipulator mounted to the top of the U A V. This is due to the instabilities that occur as the Centre of Gravity (CoG) is raised. Different methods have been proposed in literature to combat this, ranging from integrating the arm movements with the control systems of the UAV (autopilot), to designs that balance the CoG mechanically. This paper describes the design and implementation of a top mounted pantographic manipulator. Small changes in CoG will be controlled by the UAV's autopilot. The manipulator implemented is a novel design that is able to control the CoG mechanically. The design operates similar to a car jack with the end effector and counterbalance moving in an equal and opposite motion. Through bench and flight testing it was found that the manipulator can mitigate horizontal CoG movements whilst the end effector was moved with an appropriate reachability. The system is demonstrated through flight experiments and shows the feasibility of a top mounted manipulator on a UAV. This aims to provide a benefit to remote sensing and sampling applications without impacting on the flight performance. The full final flight demonstration can be seen in the following link: https://youtu.be/qBzpA1m-dA.