Unmanned automated aerial vehicles (UAV) have developed rapidly in recent years and are already available on the consumer market as camera drones and toy drones. They are also used in professional environments for monitoring and inspection tasks. Future applications include transport and delivery drones, agricultural drones and passenger transport. “Aerial manipulation", in which robotic tasks are carried out from hovering UAV platforms, is currently developing as a new field of application.
The principle of the rigid multicopter has proven itself for most of the tasks mentioned. Here, several rotors (propellers) are attached to a platform and all flight manoeuvres can be performed by varying the speed and thus the thrust of the rotors.
The frequently used quadrocopter is under-actuated and unable to apply forces and torques in all directions from its initial position. This can only be achieved with fully actuated devices that have at least 6 rotors or active tilt rotors. For this reason, such UAVs are particularly suitable as platforms for manipulation tasks.
Aerial manipulation requires new types of UAVs that are specially designed for this task. This applies to the hardware on the one hand, but in particular to the guidance, navigation and control (GNC). While a classic drone mainly has position and speed control, manipulation tasks also require forces to be controlled in certain spatial directions. In addition, a manipulation task can consist of different phases with different kinematic configurations and changing controller structures. An overview of aerial manipulation tasks currently under development is given. The mounting of a screw by a fully-actuated hexacopter is shown as an example of an air manipulation task.
