Development of the navigation system for the visually impaired

There are about 300,000 visually impaired persons in Japan. Most of them are old persons and, cannot become skillful in using a white cane, even if they make effort to learn how to use a white cane. Therefore, some instruments which support the independent activities of the visually impaired are required. In this paper, we will talk about our developed instrument which support the independent walking of the visually impaired in the indoor space. This instrument is composed of a map information system and a navigation system. In map information system, optical beacons and a receiver of them are used. Optical beacons are set on the ceiling and emit the position code as infrared signal. A receiver receives signal from beacons and informs a map information by artificial voices. The navigation system can follow the colored guide line which is set on the floor. This system is composed of a white cane and a color sensor which is set on the white cane. This color sensor senses colored guide line on the floor. If the cane is on the line, the cane informs a visually impaired user that he or she is on the guide line by vibration. Five normal subjects who were blindfolded were tested with our developed system. All of them could walk along guide line. And map information system worked well. Therefore, we have concluded that our system will be a very valuable one to support activities of the visually impaired.