AUDITORY GUIDANCE WITH THE NAVBELT - A COMPUTERIZED TRAVEL AID FOR THE BLIND

A blind traveler walking through an unfamiliar environment and a mobil e robot navigating through a cluttered environment have an important f eature in common: both have the kinematic ability to perform the motio n, but they are dependent on a sensory system to detect and avoid obst acles. This paper describes the use of a mobile robot obstacle avoidan ce system as a guidance device for blind and visually impaired people. Just as electronic signals are sent to a mobile robot's motion contro llers, auditory signals can guide the blind traveler around obstacles, or alternatively, they can pro,ide an ''acoustic image'' of the surro undings. The concept has been implemented and tested in a new travel a id for the blind, called the Navbelt. The Navbelt introduces two new c oncepts to electronic travel aids (ETA's) for the blind: it provides i nformation not only about obstacles along the traveled path, but also assists the user in selecting the preferred travel path. In addition, the level of assistance can be automatically adjusted according to cha nges in the environment and the user's needs and capabilities Experime ntal results conducted with the Navbelt simulator and a portable exper imental prototype are presented.