demonstrated their ability to ﬂy, maneuver and carry out observation
tasks in numerous roles. However, they remain passive observers,
limiting their interaction with the environment to remote surveillance.
The increasing ubiquity of UAVs will be further supported by developing
the means for these robots to contact and engage with their
surroundings robustly. The ability to manipulate objects while in
hovering flight will allow these vehicles to be used for infrastructure
maintenance and other similar tasks in locations inaccessible to
terrestrial vehicles, such as the tops of power lines and radio masts,
rough terrain or water surfaces.
When an hovering robot aircraft contacts a surface, forces are
transmitted to the airframe that may destabilize the vehicle if not
properly accounted for. Such perturbations arise both when actively
engaging and manipulating objects, as well as during inadvertent
collisions. Robustness to these forces during ﬂight is essential for
aerial robots performing physical tasks in complex real-world
environments; the vehicle must guarantee ﬂight stability throughout all
modes of operation.
Serial compliance in an end-effector acts to buffer complex aircraft
dynamics from object contact forces. Accounting for the influence of
elastic coupling to objects allows for explicit bounds within which the
aircraft’s free-air flight controller will remain stable. This allows
contact mechanisms to be designed such that an aircraft may robustly
interact with objects, even without specific knowledge of contact
conditions. Our test-bed, the Yale Aerial Manipulator, uses a flexible,
adaptive manipulator to grasp objects in flight, and has demonstrated
reliable capture of unstructured objects while hovering outdoors.
This talk will discuss key challenges in developing aerial manipulation
systems for use outdoors, with particular focus on flight stability and
end-effector stiffness, along with additional topics of interest such
as hovering accuracy for object capture and the effect of changing
system mass once an object has been grasped.