Chapter 1: Introduction

1.1 Prolog

Imagine yourself unable to read the street signs, and you are late for a job interview. You frantically ask for directions but no one can help. This is what happened to me the summer of 1992. That was the day I decided to help the visually impaired by building a device that would tell them what street intersection they are standing at. By December of that year I had built a device using GPS , a laptop computer and a voice synthesizer to verbally tell me what Carleton University street intersection I was standing at. This was my fourth year project at Carleton.
I went on to enter a number of competitions including the Ontario Engineering Competition (OEC), APEO papers night, and IEEE papers night. Placing first in the paper nights, and winning the "Social Awareness Award" from the OEC, I received a lot of press and was interviewed by a number of Carleton papers, The Citizen, and by CJOH Midday Report channel 7.

Unknown to myself, two not-for-profit companies Arkenstone Inc., California and Visuaide 2000, Montreal, independently came up with the same design. Visuaide was asking Industry Canada for development money to build this device, and because of the press I had received, my name was given to Visuaide since I had already built such a device. During that summer of 1993, Visuaide hired me to do a feasibility study for Industry Canada to justify the $250 000 grant awarded. In January of 1994, an arrangement between Arkenstone and Visuaide was done to jointly co-develop Sextant (the name of this project). Since I had built a working prototype and being the only engineer with extensive GPS experience, I was hired by Visuaide to work in California at Arkenstone for six months. While working at Arkenstone I was taught commercial C programming by Bruce Merritt the senior Engineer at Arkenstone . Bruce took me under his wing, and helped me with Windows-based programming, and I helped clarify some of the intricacies of GPS. While working at Arkenstone , I built the portable GPS system, which they used in demonstrations to potential investors.

After this six-month period I returned to Canada, continuing with my Masters, but worked effectively full time as a consultant to Arkenstone . In November of 1995, a patent was granted to Arkenstone , and I was included as one of the developers of the system. For the past four years, I have been working for Arkenstone , and was central in the development of Atlas Speaks and Strider (formerly known as Sextant). Atlas Speaks is a home-based talking map system. Strider is the mobile position-tracking system to help guide the visually impaired through the streets of a city. My contributions in the software development of the systems are shown in Fig. 13 .

1.2 Motivation

In our visually dominated world, those less fortunate have an incredible time just walking to the corner store to pick up some milk. The visually impaired don't need our pity, but do need our help to give them the ability to walk independently in our cities without the fear of getting lost. They do not want to have to rely on others around them to guide them if they are disoriented. Many of those who are visually impaired are afraid to venture out on their own in a city to which they have never been. For these reasons research on guiding pedestrians though the maze of city streets is being conducted, and a solution to this problem will be presented in this thesis.
This research will give the visually impaired this ability to explore new cities free from feelings of apprehension or anxiety. Not only will this give the visually impaired the confidence and independence to travel, but is one step closer to complete independence.

1.3 The Needs of the Visually Impaired

Those without the benefit of sight must build a mental map of their surroundings. They travel this map without ever seeing what is actually around them. They listen for cues, and use their other senses to determine where they are. They use tactile information from their cane to keep them on the sidewalk, and/or their seeing-eye dog to guide and keep them safe. They are taught to count streets, and are trained how to use the cane and/or seeing-eye dog efficiently.

In today's society of social independence, the visually impaired are severely shortchanged. The visually impaired, like everyone else want independence without going bankrupt in the process. In addition, information is key in today's electronic age. The visually impaired deserve access to this information like everyone else. Maps are not available for the visually impaired, and access to maps, in a format that they can use, is essential. They also need to be able to obtain this geographical information while travelling outside, and the system to be used must be unobtrusive, lightweight, and affordable.

1.4 Technical Overview

The system being described started as a fourth-year project by the author, and this led to Strider, a system the author has developed in cooperation with VisuAide * , Montreal, and Arkenstone Inc., California. These are non-profit organizations devoted to developing tools which allow universal access to information. Strider consists of software running on a laptop computer, an electronic GIS map of a city, a voice synthesizer, a GPS (Global Positioning System) receiver, and a DGPS (Differential Global Positioning System) receiver. This system will track the user and inform them of where they are currently located. As it stands, the current system has problems. When GPS fails the user is assumed to be at their last known position, even after they have departed from that location. In the final work represented by this thesis, an alternative system has been designed using an electronic compass to determine direction of travel, and a pedometer for measuring distance travelled. This ANS (Alternative Navigation System) will continually track the user and when GPS fails, will become to the primary navigational system.

1.5 Master Objectives

This thesis is part of a master objective for building a complete personal guidance system, which would guide pedestrians and in particular the visually impaired though the streets of a city. To this end, this system consists of three main components:

Audible access to map information, and the tools for utilizing this information.
An alternative guidance system as a backup when the primary guidance system fails.
The ability to travel outside and know one's position.

1.6 Layout

The general layout of this thesis is as follows:

Chapter 2 describes the background research that has gone into this thesis.
Chapter 3 describes Atlas Speaks, which is the first component of the thesis. It provides audible access to map information, and the tools to utilize it.
Chapter 4 describes Strider the second component of the thesis, implements mobile positioning for a pedestrian.
Chapter 5 investigates the potential flaws of Strider and offers a solution to these problems.
Chapter 6 describes the third component of the thesis, the ANS that was built.
Chapter 7 outlines the tests ANS underwent.
Chapter 8 summarizes the thesis, and presents its findings.