  We propose unwinding the rotations experienced by the user of an immersive
telepresence robot to improve comfort and reduce VR sickness of the user. By
immersive telepresence we refer to a situation where a 360\textdegree~camera on
top of a mobile robot is streaming video and audio into a head-mounted display
worn by a remote user possibly far away. Thus, it enables the user to be
present at the robot's location, look around by turning the head and
communicate with people near the robot. By unwinding the rotations of the
camera frame, the user's viewpoint is not changed when the robot rotates. The
user can change her viewpoint only by physically rotating in her local setting;
as visual rotation without the corresponding vestibular stimulation is a major
source of VR sickness, physical rotation by the user is expected to reduce VR
sickness. We implemented unwinding the rotations for a simulated robot
traversing a virtual environment and ran a user study (N=34) comparing
unwinding rotations to user's viewpoint turning when the robot turns. Our
results show that the users found unwound rotations more preferable and
comfortable and that it reduced their level of VR sickness. We also present
further results about the users' path integration capabilities, viewing
directions, and subjective observations of the robot's speed and distances to
simulated people and objects.
