Haptics-in-motion: Enhancing mixed reality workspace with dynamic encountered-type haptic display modules

Mixed reality setups with encountered-type haptic display (ETHD) can be categorized as grounded and ungrounded. Generally, grounded setups provide higher quality haptic feedback limited with smaller workspace as compared to ungrounded setups. An approach is to carry haptic modules on agile positioners. In this work, we present an immersive mixed reality setup, in which two haptic modules provide ETHD with combinations of textures and compliances. Also, a simple game is implemented to observe haptic perception. Haptic modules that match the desired texture with the desired compliance are loaded to two 2 m apart 2 m long linear positioners. Firstly, two boxes with different virtual texture-haptic compliance combinations are presented to participants repeatedly to test whether touch or vision is trusted while determining softness. Results showed that touch is preferred. Secondly, whether compliance affects the perception of textures is examined by asking participants to match three boxes (colored, textured) with three boxes on the opposite side (plain, identical) in VR according to haptic perception. Two sets of data, one with constant low compliance and one with high, were collected. Results yielded that participants distinguish textures on lower compliance more successfully. Lastly, the game is played with different compliance-texture combinations simulating six boxes on each side. It is observed that even though the success rate decreased due to the higher complexity of the task compared to the second experiment, participants expressed a higher level of entertainment. The setup enables natural encounters with different compliance-texture combinations and users responded positively about the entertainment and immersiveness of mixed reality experience with the setup.