The main advantage of using the bar code method is its very low expense.
The visually impaired would find it very hard to locate the bar code sticker on the street pole. Vandalism of the bar code stickers could not be prevented either. This method is also not very flexible; that is, the user must have physical contact with the pole. Because of the above analysis, this idea was not pursued.
Location Finder is an FM-based system. At each street intersection, a single solar celled transmitter would transmit an intermittent code cycling every 5 seconds. The hand-held receiver would pick up these FM signals and compare them with its internal data base. This enables the system to determine and articulate the user's current location.
An advantage of using FM signals is that this system would not be just limited to visually impaired people. It could be expanded to include motorists, bicyclists, tourists, etc.
The main disadvantage is that 60,000 transmitters would be required to cover all intersections in a city the size of Ottawa.
Dr. Harrison suggested that I should look into using the GPS system to determine the coordinates of the person instead of using FM transmitters at each intersection. Incorporation of GPS into my system was the basis of my entire project. The title of my system changed a number of times throughout the project. The initial title was Global Mapping System (GMS), followed by Audio Positioning System (APS). The final title was the Navigational System for the Visually Impaired (NVI). This system consists of a GPS receiver, a laptop computer, and an Intex Talker for speech synthesis. The integration of the system occurs through hardware cables and C language software that communicates between all devices. Contained within the software is the data base of the test site used to test the system, namely the streets of Carleton University.
The advantage of this system over the previous ones suggested is that this system is already in place, and can be easily configured to suit the needs of the customer.
A few disadvantages of the NVI system that must be overcome are: high cost of the GPS receiver, the collection of the data base for the city of Ottawa, miniaturization to a hand held device, and the accuracy of the GPS receiver. These issues are addressed in this report.
April 05,1993
A prototype of my project has been completed and is currently working with its limited database. The system currently weighs 15 Kg. and is quite cumbersome. The accuracy of the NVI is limited to + 100 meters, which is sufficient for this stage of its development.
I have entered three competitions with my project. In the Ontario Engineering Competition I won the Social Awareness Award, sponsored by the Association of Professional Engineers of Ontario (APEO). I took first place in the Institute of Electronic and Electrical Engineers (IEEE) Carleton Papers Night, and represented Carleton in the Regional IEEE Papers Night. The final competition entered was the Association of Professional Engineers of Ontario (APEO) Papers night.
Future
A patent for this device is currently being considered. I would like to have a functional hand held NVI unit in two years. Miniaturization of this project will start this summer if funding is found to support the hardware development.