Navigation in eight cardinal directions with pseudo-attraction force for the visually impaired

We have proposed a haptic direction indicator that will help visually impaired pedestrians to travel a path and avoid hazards areas intuitively and safely by means of force-based navigation. The haptic direction indicator uses the pseudo-attraction force technique, which generates a pulling or pushing force in portable or mobile devices by exploiting the nonlinear relationship between perceived acceleration and physical acceleration. We have investigated the angular resolution of the pseudo-attraction force for the visually impaired in a static posture to design a practical haptic direction indicator. This paper describes a prototype of a crosshair haptic direction indicator based on our previous findings. An experiment was performed to clarify the perceptual characteristics when a visually impaired pedestrian is navigated by perceiving force sensation. The results show that most of the visually impaired participants could walk in a predetermined cardinal direction with the haptic direction indicator. Finally, we discuss the drawbacks of our system and design improvements.