2006 Conference General Sessions

THE USE OF A GPS-MAPPING PROGRAM IN ORIENTATION AND MOBILITY

 

 

Presenter(s) 
Roni Hang
Guide Dogs NSW/ACT
2 — 4 Thomas St
Chatswood 2067 Australia
Day Phone: 61 2 9412 9341
Email: rhang@guidedogs.com.au

Presenter #2
John Black
2 — 4 Thomas St
Chatswood 2067 Australia
Day Phone: 61 2 9412 9347

Email: jblack@guidedogs.com.au

 

This paper critically examines the potential applications of GPS*-based mapping programs in the field of orientation as related to persons with vision impairment. The program selected for this examination is OziExplorer. The functions of the program will be explored in two main areas. Firstly, how it can be applied in aiding the instruction and teaching of orientation skills, and secondly, how it can assist persons with vision impairment address orientation challenges during travel.

The aim of this research is to illustrate the potential applications, and/or limitations, of mapping and moving map software, which is now readily available in the consumer market. Such an investigation is warranted due to the customizability of this relatively new software. Programs, such as OziExplorer, offer more extensive configuration options, making it possible to tailor to more specific user needs. With increased versatility, significant foreseeable advantages include the ability to customize functions to different user skill levels, that is, from novice to advance travelers, and the flexibility to accommodate varying technical abilities.

GPS mapping and moving map software has traditionally been used for sailing, boating, off- road driving, hiking and geocaching. Only in the last ten years has OPS mapping software incorporated street and road routing. These newer programs have the capacity to manipulate data, incorporate different sources of maps, that is, paper as well as digital maps, and these added features provide greater accuracy and make trip planning easier.

* GPS: Global Positioning System
The Project
The research presented here covers the preliminary phase of a larger multiphase project commenced in mid—2005 by Guide Dogs NSW/ACT in Australia. The overall project will research, analyze and trial the potential applications of moving map programs. Phase I, the topic of this paper, involves using OziExplorer to examine the potential applications of moving map programs. Phase II will compare the features of OziExplorer to other mapping and moving map programs. Other programs include Fugawi, GPSS, TrackRanger, Memory—Map Navigator, Outdoor Navigator, Vito and Trekker. Of these programs, Trekker is the only one
which has been developed specifically to tailor to visually impaired travelers.

While Phase I and II focus on research, Phase III and IV will undertake more practical assessments. Phase III will involve preliminary trials of moving map programs in two stages. Stage I will trial the programs in teaching orientation skills, such as the development of cognitive mapping skills, understanding of object—to—object spatial relationships, and the development of spatial updating and environmental flow monitoring skills. Meanwhile, Stage II would trial the capability of these programs in addressing orientation challenges during travel. These challenges include maintaining orientation, identification of landmarks and information points, and solving the problem of disorientation. Orientation and Mobility instructors will be present in both Stages of Phase 111. Lastly, Phase IV involves the development of recommendations for modifying and/or expanding capabilities of the software to suit the needs of blind and visually impaired users.

What features do moving map programs offer?
Moving map programs incorporate a myriad of applications with the potential to assist and enhance orientation for travelers who are blind or visually impaired. However, for the purposes of this paper, only the main (or generic) features of these programs have been identified.

Can moving map programs help teach orientation?
Features of moving map programs with the potential to aid the instruction and teaching of
orientation skills are identified in relation to the ability to assist the following:
(1) development of cognitive mapping skills;
(2) understanding of self—to—object and object—to—object spatial relationships; and
(3) development of spatial updating and environmental flow monitoring skills.

Cognitive mapping skills
An aspect of good cognitive mapping skills is an understanding of environmental concepts. Mapping programs include proximity zone alarms. These zones, when entered, will sound an

alarm. The alarm can be set as a beeping sound or customized voice recording. A feature of moving map software is the ability to manipulate these zones into different shapes. For example, a zone could be arranged into the shape of a rectangle and follow the perimeter of a building or it could follow the curvy layout of a rose garden. The ability to manipulate these shapes allows for a more accurate representation of the environment.

Self-to-object and object—to—object spatial relationships
Hill, Rieser, Hill, Hill, Halpin & Halpin (1993) undertook a study on how persons with visual impairments explore novel spaces. The study found that in the ‘distance estimation task’, the highest performing subjects used strategies that linked objects to reference points.

Waypoints are used to mark any point of interest, for example, a traffic intersection or bus stop. Moving map programs include ‘navigate to a waypoint’ feature. When activated, this feature can tell the traveler which direction a waypoint is (bearing), how far away it is (distance) and the approximate amount of time to reach the waypoint ) ‘Estimated Time Enroute’ or ETE) based on current speed.

This feature could assist O&M instructors teach the skill of linking objects to reference points by accessing information on the location of different waypoints and how distances between objects and reference points change during locomotion.

Spatial updating and environmental flow monitoring skills
Learning these skills requires improving other skills, particularly memory and the use of other senses, such as hearing and touch. To do this, a traveler needs to focus an attaining cues given by the environment and little assistance from a GPS receiver is desirable.

Proximity waypoints offer a non—intrusive method of navigating. Proximity waypoints are always present and are only activated when a traveler enters a proximity waypoint. Therefore, proximity waypoints would be particularly useful for marking dangerous areas. This leaves the traveler free to move about without interference from the GPS receiver until that is, an unsafe area is entered.

 

Another advantage of proximity waypoints, and waypoints in general, is that they are essentially a position on map. This position is made up of coordinates (latitude and longitude), which means that another OPS user, who, for example, may have passed a new construction site and recorded the coordinates of that site, can send that information La another EPS user who can then enter it into their receiver. The benefit of this is user’s ability to regularly update information about the environment as it comes to hand.
Can moving map programs assist travelers address orientation challenges?
Program features with the capability to assist travelers address orientation challenges
are identified in relation to the following skills:
(1) maintaining orientation;
(2) identification of landmarks and information points; and
(3) solving the problem of disorientation.

Maintaining orientation
Maintaining orientation is a matter of keeping track of environmental flow. As mentioned, the ability to mark proximity waypoints is a non-intrusive way of teaching environmental flow skills. However, novice travelers may require more assistance and, in this case, activating the ‘navigation’ feature would be helpful. When activated, this feature includes voice prompts that tell the traveler how far they are from a chosen waypoint. The voice prompts, for example, would sound as follows “30 meters”, “20 meters”, “10 meters”, “you have arrived”. The regularity of the voice prompts will depend on the speed ‘of travel.

Cross Track Error (XTE) information may also assist travelers in maintaining orientation. XTE is the deviation from the desired course line, that is, how far off track you are currently traveling. XTE information combined with bearing information (direction to waypoint) would be valuable in assisting a traveler maintain orientation.
3

Identification of landmarks and information points
The main benefit of using moving map programs to identify landmarks (and information points) is the ability to set ANY location as a landmark. When traveling without the aid
a of a GPS receiver, travelers must rely on environmental cues to identify landmarks. Sometimes these cues are ambiguous or intermittent (e.g. the smell of a bakery shop) or are easy to miss (e.g. a crack in the footpath).

The ability to set waypoints with a five meter radius makes finding landmarks easier and also frees—up some conscious mental effort, which can then be used to focus on improving mobility skills, for example, cane technique.

Identification of landmarks can be made even easier using routes. A ‘route’ is a collection of waypoints linked together. When navigating to one waypoint, a traveler avails him/herself to bearing, distance and STE information. However, when traveling along a route, travelers have the option of ‘forward’ and ‘reverse’ navigation. The 055 receiver will always prompt you to next waypoint in a route and will only direct you Lo the following waypoint once the proceeding waypoint has been reached.

Solving the problem of disorientation
A traveler’s ability to solve the problem of disorientation depends largely on the number of reorientation strategies they have available to them. With more strategies available, the traveler can exercise (and practice) their hypothesis testing and decision making skills, by selecting an combing strategies.

Moving map programs include several features that increase the number of reorientation strategies for travelers. These features range from providing minimal assistance to almost total navigation assistance. For minimal assistance, a traveler could activate the compass and find out which direction they are traveling. For more assistance, a traveler could opt to navigate to a waypoint and access bearing, distance and STE information.

When traveling along a route, a traveler could activate the ‘reverse navigation’ feature
and get back to the previous waypoint located just before they became disoriented, in addition, all GES receivers include a ‘tracking’ feature. This is also referred to as a ‘snail trail’ or ‘breadcrumb trail’ and is automatically activated when the GFS receiver is turned on. If all other reorientation strategies fail, a traveler can activate the ‘trackback’ feature and navigate back to their original starting position.

Conclusion
Although there has been limited development in adapting moving map programs to he none accessible by blind and visually impaired users a preliminary analysis of this software has been undertaken in line with two tenets held by Guide Dogs NSW/ACT.

The first tenet, exploring the potential of off—the—shelf technology, is based on the reality that products available to the larger consumer are generally at the cutting edge of technology. Guide Dogs NSW/ACT believe that a failure to explore these off—the—shelf technologies may translate into missed opportunities for improving the quality of life for people who are blind and visually impaired.

The second tenet focuses on lifelong learning. Guide Dogs NSW/ACT is a staunch supporter of technologies that can assist people to learn the skills that will help them achieve greater independence. Therefore, the focus of investigating the potential of CPS hardware and software is not to develop a dependence on these technologies but rather to use them to enhance orientation and mobility skills so that a visually impaired person may travel confidently with or without these devices.

References
Hill, S. W., Rieser, J. J., Hill, M.—M., Hill, N., Haipin, J., & Halpin, P. (1993).
How persons with visual impairments explore novel spaces: Strategies for good and poor performers. Journal of Visual Impairment & Blindness, 93(S), 295-301.


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