Visual-auditory substitution device for indoor navigation based on fast visual marker detection

Abstract

This paper proposes a new navigation device to assist visually impaired people reach a defined destination safely in the indoor environment. This approach based on visual-auditory substitution provides the user a 2D spatial sound perception of the destination and of nearby and dangerous obstacles. Visual markers are placed at several relevant locations to create a mesh of the building where each marker is visually accessible from another marker. A graph representation of markers locations and their connection to each other defines by a way finding algorithm the shortest path reach to the wished position. The navigation task is achieved by moving from visual marker to visual marker until the desired destination is reached. These markers can be used independently of any other system or in addition to other solutions based on geolocalisation and/or a digital building model. Moreover, further information can be associated to the markers, and therefore verbalize to the user for instance a temporary hazards, a door presence or any other usual displayed information. The passive visual markers enables to deploy easily and quickly a scalable and low-cost solution to "signpost" the environment for users. Combined with our realtime implemented obstacle detection, their analysis enables the navigational abilities of visually impaired people to be improved.

Outdoor Navigation Assistive System Based on Robust and Real-Time Visual–Auditory Substitution Approach

“…Indoor environments are manipulable spaces that can be modified to solve the localisation problem. This can be achieved by inserting active or passive RFID tags [ 14 ], Bluetooth [ 15 , 16 ] antennas for triangulation, or by locating a unique visual identifier through a visual marker uniformly distributed throughout a building [ 17 , 18 , 19 ]. However, implementing these technologies may require the integration of new transmitter beacons or visual patterns, and can be costly to cover larger environments such as urban areas.…”

“…The information encapsulated in the sound information could integrate additional semantics to the localisation, such as the colour in the SeeColor method or information useful for the navigation. Indeed, an indoor navigation aid system extends the localisation information with the nature of the surroundings or to distinguish the danger signal and the path information [ 17 ]. The navigation aid systems faced multiple challenges to be beneficial and not hinder daily life.…”