Control of a Small Unmanned Aerial Vehicle with flexible Manipulator

UAV with mounted flexible manipulator

Unmanned aerial vehicles (UAVs) as a special class of mobile robots have gained increasing interest in recent years because of a wide area of possible applications. While UAVs are so far mainly used for outdoor reconnaissance and surveillance tasks in military scenarios, future commercial applications could be in security-related tasks such as the surveillance of large areas and borders, in catastrophic scenarios, in the surveillance of pipelines or energy networks, in agriculture, in telecommunication or even in transport and logistics. UAVs are investigated since decades and current research topics are numerous, but can be mainly categorized in 1) platform technologies (UAV-construction, materials, propulsion, energy supply,..), 2) UAV-control, i.e. flight control and platform automation, 3) sensor systems (sensors for the platform states such as IMUs or mission sensors such as radar, optical sensors etc.) and sensor processing, 4) integration of UAVs in the airspace, 5) communication systems, 6) mission-control (achieving higher degrees of autonomy for mission accomplishment, e.g. navigation, planning, decision making etc.), 7) multi-UAV systems, where teams or swarms of UAVs are commonly solving tasks, e.g. by communication and coordination. However, in contrast to mobile ground-based robots which are also able to act with the help of suitable manipulators, UAVs are so far nearly exclusively used as flying sensors, i.e. are only equipped with different types of sensors providing situational awareness in the area of operation. However, the capability of aerial or flying manipulation by attaching a controllable manipulator to the UAV would also dramatically increase the spectrum of applications and thus flying manipulation using UAVs is the main area of research in this project AVEMA.

Flying manipulation using UAVs is a completely new area of research which comes with a lot of so far unsolved or not yet addressed problems. A related but easier task is pure payload transportation. Here, a payload already attached to a UAV must be transported. The major problems in payload transportation are the aerodynamic effects and the forces and torques caused by the object, leading to large disturbances of the UAV`s flight characteristics. These disturbances must be compensated by a suitable flight controller.

In contrast to pure transportation however, flying manipulation also includes the flexible gripping and handling of objects using a manipulator attached to the UAV. Regarding the class of suitable UAV types, flying manipulation requires a hovering capability of the UAV and hence mainly helicopter-like (rotary wing) UAVs are well suited for it. In general, flying manipulation comprises the manipulation of a defined object in a given environment in a specified way with the help of a flying vehicle and an attached suitable manipulator.

The main goal of the project AVEMA is the development of a control approach for flying indoor manipulation system using a small quadrotor UAV with flexible manipulator.



As extension of the idea of controlling a flexible manipulator with only one UAV,  a cooperative flying manipulation system with a Sensor- and a Manipulator-UAV as shown in the following figure is considered and will mainly investigate the required cooperative control concepts for the M-UAV (vehicle & manipulator). As main objective, different control concepts for the flight control of the vehicle as well as the manipulator control for flying manipulation based on the measurements from the cooperating S-UAV will be developed and validated.

Researchers: Dr. Somasundar Kannan, Dr. Miguel-Angel Olivares-Mendez, Jan Dentler, Prof. Dr. Holger Voos.