On ontology-based
indoor navigation for
the visually impaired
Fedor Tiršel
Motivation
l unique requirements on a navigation
system for blind or visually impaired users
l easy to implement solution for owners of
buildings
l finding accurate and reliable user location
l avoid the trial and error process
l upgrade user’s familiarity with an unknown
environment
Requirements I
l route planning and management (save, edit,
share)
l adaptive start to end route following
l accurate relative and absolute progress
feedback
l up to date hazard warning and avoidance
guidance
l general environment information
Requirements II
l non-blocking of other senses (headphones)
l voice navigation on demand
l graduated levels of functionality (novice →
expert)
l emergency request for assistance
Concept
Ideas
l adoption of smart phones as “the device”
l absence of assistive tools for navigation
(e.g. the long cane, guide dogs)
l QR codes for fully sighted, “wireless” for blind
l routing in ontology-based maps
Ontology I
l Def: a logical theory which gives explicit,
partial account of a conceptualization
l Def: an intensional semantic structure which
encodes the implicit rules constraining the
structure of a piece of reality
Ontology II
l combine different kinds
of ontological
knowledge
Special canes – Ven ze tmy
l acoustics signals overlays natural sound of the
surroundings
l information is primary send to the body skin
l information about locale
obstacles in front of whole
user body
l detection based on stereo
and 3D cameras
l representation of depth map
Special canes – RF Guide
l concept of intelligent
buildings
l routes are marked by RFID
and magnetic beacons
l cheap and available
solution
l “You are at the second floor.
There is door number 210
three meters behind you.
Watch: on both sides of the
corridor are benches.”
Summary
l to provide assistance on demand
l up to date hazards identification and level
based warnings
l sharing of knowledge
l independency of visually impaired user
l to build ontology-based maps