Application of Miniature FSK Transmitters for Improving the Orientation of the BlindPerson in Urban Environment
Karol W. Radecki, K Lukaszewicz, Juliusz Lech Kulikowski · 10th International Conference on Mobility and Transport for Elderly and Disabled PeopleJapan Society of Civil EngineersTransportation Research Board · 2004
Many various researches have been provided to improve the blind pedestrian security and mobility outdoors. The classic solutions have many disadvantages. For example the white cane has limited range of operation and can not be used to localize horizontal obstacles above the ground. The systems based on global poisition system (GPS) techniques have some limitations because the receiver should have to set at least 4 satellites to be able to calculate precise position. At urban environment this clear reception could be problematic. The most popular systems based on the infrared transmitters are quite expensive and power consumptive. Typically those systems are designed as public domain and are used to describe the public places like the metro station, public buildings or cross streets. Radio transmitters systems are used to help the blind individuals as the personal net of small radio beacons. These systems have also same limitations. They do not provide any information about the distance between the user and the nearest radio transmitter. This paper presents a new radio beacon system based on the frequency shift keying (FSK) modulation technique which is much more resistant for radio interferences present at urban environment. Using this kind of modulation the receiver is able to detect the strength of the radio signal and use this information for more precise obstacle localization. The system has been build as a personal cheap system and has been tested at Warsaw downtown environment.