GNSS orientation systems for the blind
GNSS orientation systems for the blind are satellite-based devices and software solutions that enable blind people to determine their position and orientation.
Loadstone GPS
| Loadstone GPS | |
|---|---|
| Basic data
|
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| Current version | 0.74 (May 25, 2010) |
| operating system | Symbian |
| category | Navigation software |
| License | GPL |
| www.loadstone-gps.com | |
Loadstone-GPS is a free, satellite-based orientation software that works without graphics and is programmed by the blind for the blind.
However, it is possible to load routes that have been created beforehand on a computer as series of points and to follow them.
For use by the blind or visually impaired, it is assumed that a screen reader and / or magnification software for text or Braille output hardware is available.
The name "Lodestone", from which Loadstone is derived, is the English word for magnetic iron stone , a natural magnetic rock that has been used by people for the manufacture of compasses for a very long time.
Project history
The Loadstone project is developing open source software for the use of satellite-based navigation for blind and severely visually impaired people. The software is free and currently runs on almost all Nokia devices with the S60 user interface under almost all versions of the Symbian operating system. About Bluetooth one here is GPS mouse connected to the phone.
The developers of Loadstone GPS are all blind and hail from Vancouver , Amsterdam and Glasgow . Many users from all over the world contribute with suggestions for improvement. The project was initiated in 2004 by private individuals Monty Lilburn and Shawn Kirkpatrick and, after initial development successes, made public in May 2006. So other volunteers found their way into the project. Since then the software has been continuously improved.
From version 0.70 the program is signed, which makes the installation on Nokia devices of the third edition much easier. As of version 0.71, the software also uses GPS receivers integrated in Nokia mobile phones in addition to the Bluetooth GPS devices that are already supported.
Extensive English-language instructions and various online tools have been developed and the program interface has been translated into several languages. At the moment, the technical complexity and the lack of multilingual instructions are still a major problem for many interested parties.
Nokia company largely ignores the Loadstone project and does not provide any assistance to the developers.
The program is under the GNU General Public License (GPL) and has so far only been financed by private funds from the developers and donations from mostly blind and visually impaired users.
functionality
At this point in time, Loadstone is very useful for blind people to locate certain points.
Therefore, it is currently best suited for paths or areas that you already know or that you have worked on once with a sighted helper. To do this, go to the desired locations and then save the point coordinates with a name of your choice in a personal database.
Thereafter, the program can later use the current GPS position and direction of movement to communicate which of these points are located in relation to the current location, at what distance and in which direction or direction in relation to the direction of movement. This makes orientation much easier, so that the mobility when using a white long stick or a guide dog can be greatly improved with the help of satellite navigation and the feeling of security and the range of motion of the persons concerned increases.
In addition to the classic points of interest for the blind, useful orientation points are :
- Intersections and junctions of roads and paths,
- several individual support points for curved paths
- Secured pedestrian crossings
- smaller places of interest such as park benches, post boxes, telephone boxes, etc.
When using public transport, blind people can independently determine the correct exit station with Loadstone GPS, as modern GPS receivers can usually still receive some satellite signals within transport and evaluate them to determine their position.
Sighted users of compatible cell phones can use Loadstone GPS together with a Bluetooth GPS receiver for their leisure activities geocaching . Since there are very diverse tasks to be mastered in this game, blind and visually impaired people can also be integrated well into the team and contribute their part to the solution.
Import of coordinate data
In principle, points you have created yourself can also be exchanged with other Loadstone users via an online database, but in practice this does not work well because of the currently too few and globally scattered users. The Loadstone community has developed solutions to import coordinates from various free sources such as the OpenStreetMap project. They are also looking for a sponsor who will acquire a license for commercial map data and make it available to the project and thus to blind Loadstone GPS users worldwide.
In June 2007 the Swedish company Wayfinder Systems AB launched the program running on Nokia devices. It was a variant of their navigation software Wayfinder Navigator , which is more geared towards car drivers , which also made some information about the environment useful for blind people accessible and whose user interface was optimized for screen reader software in some areas. An internet connection of the device was necessary to use it. The service was officially discontinued on April 1, 2011.
The Sendero Group has been selling a navigation solution for a number of years, but it only runs on special, very expensive PDAs for the blind from the company Humanware . The users come mainly from the English-speaking area.
GW Micro offers the Sense Nav software for its Voice Sense device , which was developed with the SDK of the Sendero Group. The hardware required is apparently not widespread in German-speaking countries.
The Canadian-New Zealand company Humanware sells the Trekker system, which runs on a standard PDA equipped with a special keyboard for the touchscreen .
GPS receiver
GNSS -based orientation programs need satellite data in order to calculate the current position and then to output information about the direction and distance to the next route point.
For sighted people, an accuracy of 10 to 20 meters is usually sufficient, as they can quickly perceive their surroundings with their eyes and therefore implement the instructions of their navigation system intuitively. For blind and visually impaired people, however, the accuracy of the geographical position determination is a much more important factor. An exact localization with an accuracy of 1 to 2 meters (white cane length) would be desirable .
A major disadvantage of GPS when used by pedestrians is the increasingly decreasing accuracy at slow speeds. This is because the receiver software can more easily calculate where the user is likely to be in the next few seconds when moving quickly, such as driving a car, as the data on the current speed and previous direction make it easier to calculate.
In addition to the signals from the American GPS system , those from the Russian GLONASS satellites and those from the European Galileo project can also be used.
Web links
Individual evidence
- ↑ Wayfinder Access Online User Manual ( Memento of September 28, 2007 in the Internet Archive )
- ↑ GW Micro Releases Free 1.2 Upgrade for the Voice Sense and SenseNav
- ↑ Trekker