Development of a Mobile Haptic Interface Improving Navigation Safety During Guidance for the Visually Impaired

Abstract

During robot-assisted navigation, visually impaired users cannot directly perceive the planned path's location and direction, leading to deviations and collisions. On the other hand, path anchoring (positioning the user along the path) and orientation guidance (aligning the user to the path) can improve navigation safety. We proposed a mobile haptic interface allowing independent control of the handle's position and force to provide both information. A 5-bar linkage-based handle was controlled along the path (path anchoring), while a path-tangential force was applied (orientation guidance). To evaluate the effects of path anchoring and orientation guidance implemented via a developed mobile haptic interface, 20 blindfolded sighted participants and 1 visually impaired participant conducted experiments. To evaluate the effectiveness of path anchoring implemented via haptic-based human–robot interaction, three guidance modes were compared: low-stiffness, high-stiffness fixed equilibrium position, and high-stiffness path anchoring. Additionally, to assess the orientation guidance functionality, conditions with and without orientation guidance force were compared. From the results, reduced path and orientation errors were observed in both blindfolded sighted participants and the visually impaired participant, without interfering with trunk-acceleration-based gait-balance indicators, by providing path anchoring and orientation information simultaneously rather than separately. Furthermore, during the experiment with the visually impaired participant, we observed that a higher guidance force may not necessarily result in better navigation or balance outcomes. Conclusively, our preliminary investigation demonstrates the promising potential of haptic-based navigation information to improve navigation safety during guidance.