Development of a wearable system for navigating the visually impaired in the indoor environment - a prototype system for fork detection and navigation -

We propose a wearable guide system for supporting the visually impaired. A wearable device equipped with a small laser range sensor and a gyroscope as sensors is developed. The sensors are attached to the user's chest. The range sensor is utilized to obtain distance information to the wall in the horizontal cross-sectional plane in front of the user. The gyroscope is adopted to estimate user's direction utilized in the fork pattern classification. The system classifies passage forks of the indoor environment into 7 patterns; left turn, straight, right turn, T-junction (left), T-junction (dead end), T-junction (right), crossroads. Based on the fork classification and prepared environmental topological map, the system instructs the user appropriate direction by voice at the fork. Experimental trials show the basic validity of the proposed system. Among 10 eye-masked subjects who join the experiment, the only two persons can reach the destination without the voice announcement. On the other hand, 8 of 10 subjects who wear the proposed wearable device can reach the destination.