Chapter 2: Background Research
Considerable research has been conducted on accurately
guiding those who are visually impaired through a city
without the aid of another person. Currently the visually
impaired have guide dogs and white canes to help keep them
safe and help guide them to their destination. The problem
with this is, the person being guided must accurately know
their route in order to tell the guide dog where they wish
to be taken. This limits the visually impaired to only
those routes that they have memorized so as not to get
lost. When such a person wishes to go to a new
destination, they must rely on others to guide them to
their destination. They have just lost their independence,
they have to rely on another person to tell them this
information because they cannot see the street signs which
sighted people take for granted. The research that the
author has conducted, will in no way replace the guide dogs
or canes, but will add to, and work in conjunction with
them. This will give the person the ability to explore
their neighborhood and feel confident that they will not
get lost.
As partial fulfillment of an undergraduate program at
Carleton University, a fourth-year project entitled
"Navigational System for the Visually Impaired"
was
designed by the author. This project showed the potential
for a commercial product, and received a lot of press
because of the social impact of such a device. Some of
these publications include GEO, New Scientist, and
Discover; a number of articles written about this report
can be found in
Appendix A
. From there, this project grew,
and two companies decided to build such a product,
Visuaide
, Montreal, and
Arkenstone
, California. The project was nicknamed "Sextant", and a
Feasibility Study was done to determine the best hardware
solution for the product as well as any potential pitfalls.
From there the design of Sextant began at
Arkenstone
, and two potential products were developed, "Atlas Speaks"
the talking map for a personal computer, and "Strider" the
mobile talking map with GPS (Global Positioning System)
positioning.
In 1993 a fourth-year project by the author was done using
GPS (Global Positioning System), a computer with an
electronic map database, and voice synthesis to communicate
to the user the street intersection at which they are
currently standing.
[1]
A number of awards, papers, and
articles relating to this project, are referenced in
Appendix A
. The objective of this fourth-year project,
which is the genesis of this thesis, was to help those who
are visually impaired navigate independently and accurately
in an unfamiliar environment.
The main concerns addressed in the fourth-year project were
the size and weight of the unit, as well as obtaining
accurate digital maps of the city. These concerns will be
discussed later.
In the summer of 1993, a feasibility study was conducted by
the author on Sextant; formerly known as the Navigational
System for the Visually Impaired. The study focused on the
hardware selection for Sextant so that it could become a
viable product. Additionally it investigated any potential
problems with the design.
An important finding from the feasibility study was the
need to have a secondary navigational system when GPS
fails.
[2]
The reasons why GPS fails, and the potential
solutions will be looked at in detail in Chapter 5.
Work on Atlas Speaks and Strider (formerly known as
Sextant) began in 1993 and continued through 1997 at
Arkenstone
. In November of 1995, a United States Patent (No.
5,470,233) was granted to the author,
Arkenstone
,
Visuaide
, and the other inventors for a "System and method for
tracking a pedestrian".
The author's personal contribution to Atlas Speaks includes
the speech-queuing software,
route
and route finding, map
overlays in the form of "
Points of Interest
", and making
Atlas Speaks accessible through Braille. Strider was
entirely designed, prototyped, and programmed by the author.
Atlas Speaks 1.0 was released to market by
Arkenstone
in February of 1996. Atlas Speaks 1.5 was released
December of 1997. Work on Strider coincided with Atlas
Speaks but a product is still not available due to lack of
funding, hardware problems and the absence of a reliable
backup system for GPS. Work done by the author as part of
this thesis on Atlas Speaks and Strider will be covered in
Chapters 3 and 4.
In 1994 a fourth-year project at Carleton University
entitled "Inertial Guidance System" was conducted by
another
student
. It was based on the author's 1993 project
"A Navigational System for the Visually Impaired"
. A
potential flaw in the navigational system occurs when a GPS
position cannot be obtained, as will be outlined in Chapter
5. This fourth-year report3 explored different ways of
overcoming this deficiency, and recommended a solution to
this problem. In Chapter 5, these alternatives are
discussed, and the final solution is arrived at. This ANS
has been designed, built, and tested. This alternative
system completes the product, allowing a person who is
visually impaired the ability to travel outside unattended
without the fear of getting lost.
Since GPS was introduced over ten years ago, a number of
applications using GPS has been developed. GPS navigation
in automobiles helps direct the driver to their destination
while providing a map of their surroundings. The system
can incorporate speech for easy access to important
information, especially when following a route while
driving. GuideStar from Oldsmobile and OnStar from
Cadillac are two such systems
[3]
. Here too, GPS is not the
only system that is used to track the automobile.
Integration of GPS/DGPS systems with an inertial guidance
system is required for continuous tracking. By using the
odometer of the car, distance travelled can be extracted,
and by using either an electronic or magnetic compass
and/or turn rate gyroscope, direction can be realized
[4]
.
The personal navigation system developed in thesis is
similar to the system found in some of today's luxury
vehicles, except that it is person-based, and relatively
inexpensive.
