The need for assistive devices has, had and will have a large merit in many engineering research arenas. This dissertation deals with the design, modeling, implementation and experimentation of the navigation component of a wearable assistive system for blind and visually impaired people, called TYFLOS (ΤΥΦΛΟΣ) which is the Greek word for “Blind”.
The current prototype consists of two mini cameras attached to a pair of conventional eye-glasses, a 2D tactile display vibration array) which consists of 16 vibrating elements arranged in a 4x4 manner, attached to an elastic vest worn on the user‟s abdomen, a portable computer, an ear-speaker and a microphone.
The Tyflos Navigator is an Electronic Travel Aid (ETA) with primary goal to help users towards their independent mobility in indoor environment. Its main sensor unit, the stereo vision system, captures environmental information from the user's field-of-view. 3D representations are created and moving objects are identified using stereoscopic vision and motion detection methodologies. The high resolution output of the methodologies is projected on the low resolution vibration array via a high-to-low methodology based on navigation criteria and modeled with a formal language called Vibration Array Language (VAL). The spatial distribution and temporal characteristics (varying frequencies) of the vibrating elements of the vibration array can inform the user for safe navigation paths and obstacles, giving distance and location information.
All parts of the system will be continuously adapted until the users' needs are fulfilled or the technological constraints are reached. A step towards that goal will be shown at the last part of this work with the development of a tactile vocabulary and the experimentation with users where they provide feedback giving us directions for refinements, changes and future work.