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6th European eAccessibility Forum
Putting eAccessibility at the core of information systems

26/03/2012, 9:00 - 18:00
Cité des sciences et de l'industrie, Paris

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Making urban information systems accessible to people with disabilities

Jacques Lemordant (Grenoble, France)

Speaker's information

Jacques Lemordant photo

Jacques Lemordant is a researcher in the project team WAM (INRIA-UJF-LIG) at INRIA. Since 2007 he works in the framework of the Autonomy project, which aims to improve the autonomy of the visually impaired, by facilitating their travel, inside or outside of buildings, and their access to public transport. The project brings together transportation public services, ICT companies and research organizations. It will continue for the period 2011-2014 in the framework of the European project VENTURI (immersiVe ENhancemenT of User-woRld Interactions).



Warning : The summaries of this conference have been prepared by BrailleNet who accept any responsibility for them. But presentation materials provided for download (full-papers or slides) have been provided by the authors themselves. They contain more details, more links than the following summary. Please also see the video for the full presentation.

Jacques will describe Web and mobile technologies that can be used to make an urban information system accessible to disabled people and enable them to better live in their city. In general he will discuss the possibilities of new technologies to create Augmented Reality environments integrated into the information systems that surround us.


The opendata movement exemplified by OpenStreetMap, MEMS sensors in mobile phones (accelerometers, magnetometers, gyroscopes), web and augmented reality technologies, increase in power of mobile phones will drive the change in our thinking of an accessible town by allowing us to build energy efficient pedestrian navigation systems incorporating queries on realtime information systems offered by companies running transportation systems and on customized and collaborative onboard geographical data. Accessing anywhere and anytime these two kinds of information together with new ways to interact with information systems will allow accessible autonomous navigation.

Next Generation Pedestrian Navigation Systems

GPS navigation systems when used in an urban environment are limited in precision and only capable to give instructions at the level of the street and not of the sidewalk. This does not mean that they are not useful even for visually impaired people as shown by Kapten or Sendero products. GPS allows not only guidance along routes but also a lookaround mode with point of interest (POI) information. This is allowed by the fact that GPS technology can provide absolute positioning. But GPS is limited to outdoor navigation and requires some delicate transitioning system when switching to another positioning system to allow indoor navigation.

Next generation urban pedestrian navigation will be based on Inertial Measurement Unit (IMU) and will run on mobile phone with onboard geographic data and routing engine. Our prototype IMU-based navigation system running on iPhone called IXE, has shown that a precision of one step is attainable, guidance being done through a mix of spatialized vocal instruction and 3D audio.

See this video showing IXE in action in front of Grenoble railway station:



With IXE, the distinction between indoor and outdoor is blurred as an IMU-based location engine can run indoor and outdoor if a navigation graph is provided. IMU-based navigation can be qualified as macro-navigation and one of its main characteristic is to allow guidance along routes and not in a lookaround mode. We are actually coupling IXE with a GPS lookaround mode which will allow recovery on route's checkpoints when the dead-reckoning process breaks for some reason.

Querying the environment

Mobile Geo, an accessible GPS mobile software solution from Code Factory and Sendero, in addition to the traditional search criteria such as name, street, City, and web address, allows you to search for points of interests in a specific direction of travel. Can we push this characteristic a little further by using augmented reality concepts like show below?

Another  characteristic of IXE is to allow queries on real-time bus information and on customized onboard geographical data. Queries on geographical data, nodes or POIs, ways and relations are predefined for efficiency and quality of information reasons. We used augmented reality technologies issued from a project called Grenoble, augmented town.

See this video showing outdoor queries:


Complex queries can be done through categorization both in time, space and type. Using embedded sensors, it's possible to design accessible user interfaces and a queue mechanism useful to prevent visual and audio information overwhelming.

We have implemented queries for three kinds of geographical elements: nodes, ways and relations. Queries are done using XPath with tag or child element predicates, union operator and wildcards. Queries are done directly on onboard geographical data.

See this video showing complex indoor queries:



Accessing real-time data from transportation systems.

Transportation systems have not follow the opendata movement and the information  that they own is not yet public. However in some towns and through specific agreements, real-time data for bus transportation can be accessed through web services and communication of the information in text2speech to visually impaired people is feasable. We have done this in Grenoble. Railways stations and airports are the main challenge when people with disabilities undergo complex long distance traveling. Electronic ticketing being the norm, it should be possible to provide personnalized real-time information such as gate or plateform numbers in a near future.

Authoring of routes and queries using OpenStreetMap.

By using the concept of micro-format, one can define inside OpenStreetMap a format for pedestrian navigation networks with a precision at the level of sidewalks when outdoor and of corridors  inside buildings. The big advantage of doing this instead of defining new XML languages is that we can use the standard OpenStreetMap editor JOSM to produce these networks in a short amount of time.

See this video showing the making of the Grenoble railway station route(in French)



IXE in its last version is a mobile navigation system requiring no infrastructure, configurable for pedestrians, bicycles and caddies of shopping centers. IXE supports queries on  the environment using an augmented reality interface. Because of its multimodal interface (audio, haptic, graphic), it offers accessibility to people with all types of disabilities. By using  embedded sensors in mobile phones for localization instead of GPS, IXE is energy efficient and allows indoor-outdoor navigation. Routes are easily customizable because IXE is based on the use of micro-formats inside OpenStreetMap.

IXE works on any mobile phone and is based on web technologies. Its heart is composed of two engines hence its name (Interactive eXtensible Engines), one for the audio and the other one for dead-reckoning navigation, allowing quick reconfiguration for extremely varied applications.

IXE future application area will be:

The future of pedestrian navigation

Micro-navigation builds upon embedded software ability to create a greater awareness of immediate environment, using texture-based tracking or vision algorithms and relating this information to map and IMU data. Micro-navigation includes avoiding obstacles, locating a clear path in the proximate surroundings or at a complex crossing, finding objects and providing absolute positioning using known landmarks or beacons. Micro-navigation works at a precision level of  a few centimeters by using predefined landmarks.

Macro-navigation refers to the actions required to find a route in a larger, not immediately perceptible environment and builds upon carefully designed pedestrian-ways incorporating speech instructions, audio guidance, environmental queries and IMU instructions among other things. Macro-navigation works at a precision level of one step using carefully designed routes with map-matching instructions.

There is a duality relation between micro-navigation and macro-navigation. Micro-navigation is based on a localization system giving an absolute position which allows to compute a relative position with respect to the planned route. Macro-navigation is based on a localization system giving a relative position which allows to compute an absolute position on the route through a process called map-matching. As a consequence, this two kinds of navigation complement and enhance each other.

Global navigation is based on an absolute global localization system like the GPS. Its precision is that of a few meters if used in a adequate geographical environment where data from external sensors is accessible. It can be use to bootstrap macro-navigation.

MMG navigation, i.e. the join use of micro, macro and global navigation, will allow to build richer and more precise AR mobile applications in such fields as cultural heritage visits, outdoor games and guidance of people with disabilities.


IXE is being developed by the WAM Project Team (LIG) at INRIA Grenoble. More information can be found at the following URL: http://wam.inrialpes.fr

The main contributors are Yohan Lasorsa, David Liodenot, Mathieu Razafinahaso and Jacques Lemordant.




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