Toward physically realistic vision in teleoperation: A user study with light-field head mounted display and 6-DoF head motion

Abstract

Besides haptics, the visual channel provides the most essential feedback to the operator in teleoperation setups. For optimal performance, the view on the remote scene must provide 3D information, be sharp, and of high resolution. Head-mounted displays (HMD) are applied to improve the immersion of the operator into the remote environment. Still, so far, no near-eye display technology was available that provides a natural view on objects within the typical manipulation distance (up to 1.2 m). The main limitation is a mismatch of the 3D distance and the focal distance of the visualized objects (vergence-accommodation conflict) in displays with fixed focal distance. This conflict potentially leads to eye strain after extended use. Here, we apply a light-field HMD providing close-to-continuous depth information to the user, thus avoiding the vergence-accommodation conflict. Furthermore, we apply a time-of-flight sensor to generate a 2.5D environment model. The displayed content is processed with image-based rendering allowing a 6 degree-of-freedom head motion in the visualized scene. The main objective of the presented study is evaluating the effects of view perspective and light-field on performance and workload in a teleoperation setup. The reduction of visual effort for the user is confirmed in an abstract depth-matching task.