Encountered-type haptic display for large VR environment using per-plane reachability maps

Abstract

We show a novel encountered-type haptic system, H-Wall, to enable haptic feedback using a manipulator of seven degrees of freedom suitable for simulating indoor virtual reality environments, which are characterized and confined by a set of vertical walls and revolving doors. At runtime, our system tracks hand motion using a red–green–blue depth sensor and locates its configuration. Then, the robotic manipulator plans a trajectory for the end effector, attached to a rectangular rigid board, to make contact with the hand to deliver a sense of touch as long as the perceived hand contact force is substantial. The force feedback is generated in a passive sense for static walls that the rigid board, corresponding to a vertical wall, holds its position as long as the perceived hand contact force is substantial. For a revolving door, the force feedback is generated in an active sense based on impedance control. In order to address the issue of limited workspace, we also propose a new reachability map, called per-plane reachability map, that is optimized to answer whether passive haptic feedback can be generated by a manipulator when the user touches a vertical wall at a given orientation. We successfully demonstrate our system to provide an illusion to the user in a virtual environment with touch sensation to the surrounding environment. Copyright © 2018 John Wiley & Sons, Ltd.