Indoor Navigation by People with Visual Impairment Using a Digital Sign System

Abstract

There is a need for adaptive technology to enhance indoor wayfinding by visually-impaired people. To address this need, we have developed and tested a Digital Sign System. The hardware and software consist of digitally-encoded signs widely distributed throughout a building, a handheld sign-reader based on an infrared camera, image-processing software, and a talking digital map running on a mobile device. Four groups of subjects—blind, low vision, blindfolded sighted, and normally sighted controls—were evaluated on three navigation tasks. The results demonstrate that the technology can be used reliably in retrieving information from the signs during active mobility, in finding nearby points of interest, and following routes in a building from a starting location to a destination. The visually impaired subjects accurately and independently completed the navigation tasks, but took substantially longer than normally sighted controls. This fully functional prototype system demonstrates the feasibility of technology enabling independent indoor navigation by people with visual impairment.

Wayfinding in Healthcare Facilities: Contributions from Environmental Psychology

“…In looking at the literature, there is a considerable emphasis on devices using auditory and/or haptic feedback that serve those with cognitive and/or sensory impairments [50,51,52,53] and less emphasis on those without such challenges. Legge et al [52] present a Digital Sign System (DSS) providing location sensing by using digital signs (tags) that are detected by a reader held by the user.…”

“…Legge et al [52] present a Digital Sign System (DSS) providing location sensing by using digital signs (tags) that are detected by a reader held by the user. The major difference between the sighted controls and those with visual impairments was the speed of locating targets.…”

An indoor navigation architecture using variable data sources for blind and visually impaired persons

“…Also based on visual recognition, the Digital Sign System [15] uses digitally-encoded signs distributed throughout a building. This signs give information about is location and help users finding nearby point of interest and navigate to a desired destination.…”

Towards a Sign-Based Indoor Navigation System for People with Visual Impairments

“…The user can lock onto a salient landmark in the space and the system will provide audio feedback to guide him/her towards the target. On the other hand [6] presents the Digital Sign System, a computer vision approach that uses infrared retroreflective markers and a handheld camera with an infrared light that enhances the markers' detectability and can be used for both indoor exploration and navigation.…”