GPS for the visually impaired

There have been many attempts at integrating Global Positioning System into a navigation-assistance system for the blind. GPS was introduced in the late 1980s and since then there have been several research projects such as MoBIC, Drishti, and Brunel Navigation System for the Blind, NOPPA, BrailleNote GPS and Trekker.

MoBIC
MoBIC means Mobility of Blind and Elderly people Interacting with Computers, which was carried out from 1994 to 1996 supported by the Commission of the European Union. It was developing a route planning system which is designed to allow a blind person access to information from many sources such as bus and train timetables as well as electronic maps of the locality. The planning system helps blind people to study and plan their routes in advance, indoors.

With the addition of devices to give the precise current position and orientation of the blind pedestrian, the system could then be used outdoors. The outdoor positioning system is based on signals and satellites which give the longitude and latitude to within a metre; the computer converts this data to a position on an electronic map of locality. The output from the system is in the form of spoken messages.

Drishti
Drishti is a wireless pedestrian navigation system. It integrates several technologies including wearable computers, voice recognition and synthesis, wireless networks, Geographic information system (GIS) and GPS. It augments contextual information to the visually impaired and computed optimized routes based on user preference, temporal constraints (e.g. traffic congestion), and dynamic obstacles (e.g. ongoing ground work, road blockade for special events).

The system constantly guides the blind user to navigate based on static and dynamic data. Environmental conditions and landmark information queries from a spatial database along their route are provided on the fly through detailed explanatory voice cues. The system also provides capability for the user to add intelligence, as perceived by the blind user, to the central server hosting the spatial database.

Brunel navigation system for the blind
Prof. W. Balachandran is the pioneer and the head of GPS research group at Brunel University. He and his research team are pursuing research on navigation system for blind and visually impaired people. The system is based on the integration of state of the art current technologies, including high-accuracy GPS positioning, GIS, electronic compass and wireless digital video transmission (remote vision) facility with an accuracy of 3~4m. It provides an automated guidance using the information from daily updated digital map datasets e.g. roadworks. If required the remote guidance of visually impaired pedestrians by a sighted human guide using the information from the digital map and from the remote video image provides flexibility.

The difficulties encountered includes the availability of up to date information and what information to offer including the navigation protocol. Levels of functionality have been created to tailor the information to the user’s requirements.

NOPPA
NOPPA navigation and guidance system was designed to offer public transport passenger and route information using GPS technology for the visually impaired. This was a three-year (2002~2004) project in VTT Industrial Systems in Finland. The system provides an unbroken trip chain for a pedestrian using buses, commuter trains and trams in three neighbor cities’ area. It is based on an information server concept, which has user-centered and task oriented approach for solving information needs of special needs groups.

In the system, the Information Server is an interpreter between the user and Internet information systems. It collects, filters and integrates information from different sources and delivers results to the user. The server handles speech recognition and functions requiring either heavy calculations or data transfer. The data transfer between the server and the client is minimized. The user terminal holds speech synthesis and most of route guidance.

NOPPA is currently able to offer basic route planning and navigation services in Finland. In practice, the limits are map data can have outdated information or inaccuracies, positioning can be unavailable or inaccurate, or wireless data transmission is not always available.

BrailleNote GPS
The BrailleNote GPS device is developed by Sendero Group, LLC, and Pulse Data International, now called Humanware, in 2002. It is like a combination of a personal digital assistant, Map-quest software and a mechanical voice.

With a receiver about the size of a small cell phone, the BrailleNote GPS utilizes the GPS network to pinpoint a traveler’s position on earth and nearby points of interest. The personal computers receive radio signals from satellites to chart the location of users and direct them to their destination with recorded voice commands. The system uses satellites to triangulate the carrier’s position, much like a ship finding its location at sea.

Visually impaired people can encode points of interest such as local restaurants or any other location, into the computer’s database. Afterward, they can punch keys on the unit’s keyboard to direct themselves to a specific point of interest.

Trekker
The Victor Trekker, designed and manufactured by Canada-based company VisuAid, was launched on March 2003. It is a personal digital assistant (PDA) application operating on a Pocket PC, adapted for the blind and visually impaired with talking menus, talking maps and GPS information. Fully portable (weight 600g), it offered features enabling a blind person to determine position, create routes and receive information on navigating to a destination. It also provided search functions for an exhaustive database of point of interests, such as restaurants, hotels, etc.

It is fully upgradeable, so it can expand to accommodate new hardware platforms and more detailed geographic information.

Trekker and Maestro, which is the first off-the-shelf accessible PDA based on Windows Mobile Pocket PC, are integrated and available in May 2005.

Trinetra
The Trinetra project aims to develop cost-effective, independence-enhancing technologies to benefit blind people. One such system addresses accessibility concerns of blind people using public transportation systems. Using GPS receivers and staggered Infrared sensors, information is relayed to a centralized fleet management server via a cellular modem. Blind people, using common text-to-speech enabled cell phones can query estimated time of arrival, locality, and current bus capacity using a web browser.

Trinetra, spearheaded by Professor Priya Narasimhan, is an ongoing project at the Electrical and Computer Engineering department of Carnegie Mellon University. Additional research topics include item-level UPC and RFID identification while grocery shopping and indoor navigation in retail settings. Additional information can be found here: http://www.ece.cmu.edu/~trinetra/