Development of the navigation system for the visually impaired by using optical beacons

Our objective is the development of a navigation system which is used in indoor spaces and supports activities of the visually impaired without the help of others. The system is composed of optical beacons which are set on the ceiling and emit the position code as an infrared signal, an optical receiver which receives signals from beacons, and a navigator which guides a user by an artificial voice. Three subjects with low vision were tested in a hospital with our navigation system. 49 optical beacons were set on the ceiling, and the subject equipped with an optical receiver and a navigator. Each subject walked from the start point to the destination following the guidance voice. From these experiment, the following characteristics became clear. (1) On a pathway where a subject can feel the wall, every subject could follow the navigation voice. (2) Some subjects couldn't go across a wide pathway in a straight line, and then the system lost their position. Therefore, if the problem of crossing the pathway is improved, our navigation system will be a very valuable one to support activities of the visually impaired.