Examining Distance in UAV Gesture Perception

Karissa Jelonek, Paul Fletcher, Brittany Duncan, Carrick Detweiler

Abstract:

Unmanned aerial vehicles (UAVs) are becoming
more common, presenting the need for effective human-robot
communication strategies that address the unique nature of
unmanned aerial flight. Visual communication via drone flight
paths, also called gestures, may prove to be an ideal method.
However, the effectiveness of visual communication techniques
is dependent on several factors including an observer’s position
relative to a UAV. Previous work has studied the maximum
line-of-sight at which observers can identify a small UAV [1].
However, this work did not consider how changes in distance
may affect an observer’s ability to perceive the shape of a
UAV’s motion. In this study, we conduct a series of online
surveys to evaluate how changes in line-of-sight distance and
gesture size affect observers’ ability to identify and distinguish
between UAV gestures. We first examine observers’ ability to
accurately identify gestures when adjusting a gesture’s size
relative to the size of a UAV. We then measure how observers’
ability to identify gestures changes with respect to varying
line-of-sight distances. Lastly, we consider how altering the
size of a UAV gesture may improve an observer’s ability to
identify drone gestures from varying distances. Our results
show that increasing the gesture size across varying UAV to
gesture ratios did not have a significant effect on participant
response accuracy. We found that between 17 m and 75 m
from the observer, their ability to accurately identify a drone
gesture was inversely proportional to the distance between the
observer and the drone. Finally, we found that maintaining a
gesture’s apparent size improves participant response accuracy
over changing line-of-sight distances.