A Wearable Two-Sensor O&M Device for Blind College Students

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A major problem for visually impaired college students is independent campus
navigation. Many universities, such as Utah State University (USU), have no Orientation
and Mobility (O&M) instructors. Thus, visually impaired undergraduates must rely on
their friends, siblings, and even parents to learn their way around a large campus, which
reduces their sense of independence. This paper describes a wearable two-sensor O&M
device for visually impaired USU undergraduates and presents a single subject feasibility
test that estimates how a visually impaired navigator can use the device to learn new
routes on the USU campus.

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A Wearable Two-Sensor O&M Device for Blind College Students

  1. 1. A Wearable Two-Sensor O&M Device for Blind College Students John Nicholson and Vladimir Kulyukin Computer Science Assistive Technology Laboratory Department of Computer Science Utah State University Logan, UT 83422-4205ABSTRACTA major problem for visually impaired college students is independent campusnavigation. Many universities, such as Utah State University (USU), have no Orientationand Mobility (O&M) instructors. Thus, visually impaired undergraduates must rely ontheir friends, siblings, and even parents to learn their way around a large campus, whichreduces their sense of independence. This paper describes a wearable two-sensor O&Mdevice for visually impaired USU undergraduates and presents a single subject feasibilitytest that estimates how a visually impaired navigator can use the device to learn newroutes on the USU campus.KEYWORDSVisual impairment; blindness; assisted navigation; outdoor navigation; GPS; digitalcompassBACKGROUNDEach year USU accepts a few visually impaired students [3]. The most difficult period forthese individuals is the first semester when they do not know the campus and have to relyon sighted guides, e.g., siblings, friends, classmates, and even parents, to find their wayaround. The problem is recurrent in that a blind student must learn new routes everysemester when the student takes a class that meets in a building he or she has nevervisited before. It is hoped that the proposed device will be available to the new visuallyimpaired students through the Disabled Students Resource Center. The students willcheck out such a wayfinding device upon arrival, use it until they become comfortablewith the campus, and return it back to the Center. It is important to note that, unlike mostparadigms in assisted navigation, this paradigm does not attempt to create a devicedependency. Instead, the objective is to create a device that is used only temporarily untilits user achieves the required level of navigation independence in a given environment.HYPOTHESISIt is hypothesized by the investigators that a wearable system that consists of a smallcomputational unit, a GPS receiver, a digital compass, a headphone, and a text-to-speechengine can enable a visually impaired navigator learn new routes independently. Thisresearch is inspired by the findings of the research group at the University of California atSanta Barbara headed by Loomis and Klatzky that has been doing basic and appliedresearch on the Personal Guidance System (PGS), a navigation system for the visually
  2. 2. impaired [1]. The main differences between the research presented in this paper and thePGS research are: 1) a novel GPS-based localization method, 2) addition of a digitalcompass to the suite of sensors, 3) exclusion of 3D audio for information delivery, and 4)focus on independent route learningMETHOD--------------------------------------Insert Figures 1, 2, and 3 here.--------------------------------------The current prototype, called WayFinder, (see Figure 1) is worn as a vest. The systemconsists of a GPS unit on one shoulder and a digital compass on the other shoulder. Acomputational unit sits in the front on the user’s chest with an attached numeric keyboardwhich allows the user to enter commands and respond to prompts from the system. APCMCIA wireless card can be inserted on the bottom of the computation unit although itis not currently used in outdoor environments. The system has headphones which allowthe user to hear the system give commands and prompts. Figure 2 shows the hardwarecomponents of the WayFinder hardware platform in an acrylic container attached to thevest. Figure 3 shows the hardware architecture.In outdoor environments, the system relies on a modified use of GPS for localization inorder to increase accuracy [2]. GPS data can also be used to infer directionality but it isnot reliable due to signal drift caused by errors with GPS data. Thus, it can appear thatthe latitude and longitude of a user are changing even when the user is standing still. Adigital compass overcomes this by providing reliable direction information. Currently,the compass is used to orient the user to the proper direction before they begin their routeand then, as the user is moving along a route, it periodically reports the current directionto the userWhen the user desires to go to a new destination, the user first enters the destination intothe system through a small wearable keypad. When the user is ready to start, the systemorients the user using the compass so that the user starts walking in the correct direction.As the user moves along the desired route the system periodically informs the user of hisor her direction the user or tells the user what action needs to be taken: continue walkingforward, turn left or turn right. When the user reaches the desired destination, the systemgives final instructions such as how far away the door to the building is. The only timethe user actually has to enter information into the system is at the beginning of a walk.The desired destination is chosen by navigating a voice-based directory of availabledestinations.--------------------------------------Insert Figure 2 here.--------------------------------------In order to see if the device can aid a person in learning new routes, four routes (see
  3. 3. Figure 2) were chosen on the Utah State University campus. The routes were the paths auser would take to get from building to building. When combined, the four routes form aloop with the user ending up at the start position of route 1 when he finished route 4. Theroutes all kept the user on the sidewalk.The test subject was a visually impaired USU graduate student who is a guide doghandler. Over each route the system correctly instructed the user when and whichdirection to turn, and periodically reported the compass direction to the user Upon arrivalit gave final instructions on how to enter the building. After completing the loop of testroutes once using the Wayfinder, which took approximately 15 minutes, the user wasasked to repeat the loop with out the device.RESULTSThe subject successfully completed all four routes. After the test was completed, the testsubject stated that route 3 was the most difficult route, because it contained a longstraight path. He noted that one of the buildings he passed by had a furnace which hecould hear during the walk with the Wayfinder. On the walk without the Wayfinder, heused that furnace noise to time how long he had to walk before turning onto the sidewalkfor the Ag Science destination. Although the test subject did not know the routes inadvance, he was familiar with the area. A true test of the system will require test subjectswho are totally unfamiliar with both the routes and the area. While the user really likedthe functionality of the system and understood that it was just a test bed, he suggestedthat the system must be smaller and less conspicuous.REFERENCES1.Golledge, R. G., Marston, J. R., Loomis, J. M., & Klatzky, R. L. (2004). Statedpreferences for components of a Personal Guidance System for non-visual navigation.Journal of Visual Impairment and Blindness, 98(3)2. Kulyukin, V. and Nicholson, J. (2005). On Overcoming Longitudinal and LatitudinalSignal Drift in GPS-Based Localization Outdoors. Proceedings of the RehabilitationEngineering and Assistive Technology Society of North America (RESNA). Atlanta, GA.3. E. Lawyer. Utah State Projects Assist the Blind. Utah Statesman, Sept. 26, 2005.ACKNOWLEDGMENTSThe study was funded, in part, by two Community University Research Initiative (CURI)grants from the State of Utah (2003-04 and 2004-05) and NSF Grant IIS-0346880. Theauthors would like to thank Mr. Sachin Pavithran, a visually impaired training anddevelopment specialist at the USU Center for Persons with Disabilities, for his feedbackon the localization experiments.
  4. 4. TABLES AND FIGURES------------------------Figure 1. Photograph of the Wayfinder------------------------Alternative Text Description for Figure 1.Figure 1 shows a photograph of the Wayfinder system being worn.
  5. 5. ------------------------Figure 2. Map of Routes------------------------Alternative Text Description for Figure 2.Figure 2 shows the four routes taken and learned by the user during the proof of concepttests. The four buildings involved in the test were Old Main, Merrill Library, Ray BWest, and Ag Sciences. Route 1 goes east from Old Main to Merrill Library. Route 2goes west and then south from Merrill Library to Ray B West. Route 3 goes north, theneast, and then north again from Ray B West to Ag Sciences. Route 4 goes south and thenwest from Ag Sciences to Old Main.

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