Unwinding Rotations Reduces VR Sickness in Nonsimulated Immersive Telepresence

TL;DR

This paper tests whether unwinding rotations, which decouples the user's viewpoint from camera rotations during immersive telepresence, reduces VR sickness when using real video streams from a $360^\circ$ camera mounted on a robotic arm. In a preregistered within-subject study with $n=36$, participants experienced two conditions (UR and CR) via prerecorded videos projected into a Unity VR scene, performing an inspection-like primary task and a secondary attention task. Results show UR significantly lowers VR sickness and increases comfort and user preference, with no meaningful detriment to task performance; this supports the method's applicability to real-world, high-immersion telepresence scenarios. The findings suggest that UR can improve user experience in environments with 3D robot motion (e.g., underwater, aerial, or space contexts) without sacrificing efficiency, making high-immersion teleoperation more usable in practice.

Abstract

Immersive telepresence, when a user views the video stream of a $360^\circ$ camera in a remote environment using a Head Mounted Display (HMD), has great potential to improve the sense of being in a remote environment. In most cases of immersive robotic telepresence, the camera is mounted on a mobile robot which increases the portion of the environment that the remote user can explore. However, robot motions can induce unpleasant symptoms associated with Virtual Reality (VR) sickness, degrading the overall user experience. Previous research has shown that unwinding the rotations of the robot, that is, decoupling the rotations that the camera undergoes due to robot motions from what is seen by the user, can increase user comfort and reduce VR sickness. However, that work considered a virtual environment and a simulated robot. In this work, to test whether the same hypotheses hold when the video stream from a real camera is used, we carried out a user study $(n=36)$ in which the unwinding rotations method was compared against coupled rotations in a task completed through a panoramic camera mounted on a robotic arm. Furthermore, within an inspection task which involved translations and rotations in three dimensions, we tested whether unwinding the robot rotations impacted the performance of users. The results show that the users found the unwinding rotations method to be more comfortable and preferable, and that a reduced level of VR sickness can be achieved without a significant impact on task performance.

Figures (6)

• Figure 1: (a) When camera rotations are not unwound, the user's viewpoint is coupled with the camera rotations. (b) The camera rotations are unwound to decouple the user's viewpoint from the camera rotations.
• Figure 2: Unwinding the camera rotations by rotating a virtual camera frame (unwound camera frame).
• Figure 3: An example object (a switch box) used for the primary task shown in two possible states.
• Figure 4: Secondary task of detecting and tagging aliens in the environment. (a) The two types of alien stickers used in the experiment. (b) An instance of alien placement in the environment.
• Figure 5: Comparisons of distributions corresponding to different conditions. The box represents the interquartile range, with whiskers extending to the minimum and maximum values excluding outliers, which are plotted as dots. A horizontal line marks the median and a cross indicates the mean.