Development of navigation system for the blind using GPS and mobile phone combination

A single GPS (Global Positioning System) or differential GPS receiver is a useful tool for the blind for determining their location relative to the surrounding environment. However, each person needs to carry his/her own personal computer loaded with location data, and these data have to be updated periodically for each area. We therefore developed a new guidance system to solve these problems by using GPS receivers and a mobile phone. In the experiments on campus, we confirmed the automatic on-line personal guidance function. The maximum error of the determined position was 16 m. The weight of the mobile unit was under 2 kg.