Radio tags give guidance
Technology Research News
University of Rochester researchers have
found a new use for the radio frequency identification tags that manufacturers
are aiming to use to track products like cartons of milk and sweaters.
These radio ID tags contain small radio transponders that broadcast
unique identification numbers. Radio receivers can monitor the tags to
track inventories in real time. The cheap tags make tracking from the
factory to the consumer cost-effective; they have also become a source
of concern because they could be used to record individuals' movements
and purchasing habits.
The Rochester team has reversed the standard radio tag setup by
making the receivers mobile and the transponders fixed; the arrangement
provides information at certain points in space. "We reversed the usual
application of fixed reader and... portable tag to... use fixed tags to
let a person know where they are," said Jack Mottley, an associate professor
of electrical and computer engineering and adjunct associate professor
of biomedical engineering at the University of Rochester.
The system, dubbed Navigational Assistance for the Visually Impaired
(NAVI), can provide location information for the visually impaired and
for other kinds of navigational assistance applications like self-guided
The system includes a set of permanently mounted passive transponders
and a reader/playback device carried by the user. Rather than tipping
off an inventory system when a specific item is near, a transponder trips
a particular CD track when a playback device comes within range.
The system could be a low-cost alternative to global positioning
system-based schemes for providing location-specific information and pedestrian
For applications for the visually impaired, transponders could
be mounted near key points like hallway intersections. For tour applications,
transponders would be mounted near items of note, and near places where
people might need directions.
Once the passive transponders are installed at key points, "the
user will simply turn on the device, make sure the correct CD is installed,
and then put on... headphones," said Mottley. "As they pass by the transponder
the CD player will turn on and play a particular track -- say track number
3," he said.
If, for example, the application is for the visually impaired,
the track might say "front of Rush Rhees library," said Mottley. Rush
Rhees is the main library at the University of Rochester.
A CD intended for self-guided tours might have a longer message
that gives the history of the building and points out some other items
of note near the fašade, then gives directions to enter the library and
turn left, said Mottley. As the user continues walking, additional transponders
trigger other tracks, he said.
The researchers' initial idea was to use a digital voice recorder
like those used in digital answering machines to play the messages. They
found that using removable media like CDs was easier, however. The tricky
part of putting the system together was combining the identification tracking
function used by the radio frequency system with the audio playback portion
of the CD system.
The system is made from off-the-shelf parts, and is relatively
inexpensive to implement because radio frequency transponders are cheap,
simple and durable. They do not contain power supplies, and work even
when they are painted.
The researchers' prototype is several times bigger than a portable
CD player, but could eventually be close to that size, according to Mottley.
The researchers are looking to improve the prototype with a longer-range
tag reader. "We need to achieve about a 2 meter read range," Mottley said.
The system could eventually be used in self-guided tours of places
like museums, and as a way to give people directions in complicated and
confusing buildings like medical centers, according to Mottley.
The method could be used in commercial products in less than two
years, according to Mottley. "The technology is all there and ready to
go," he said. Mottley came up with the method along with a group of students:
Chris Alden, David Wolpert, Christina Lee, Erica Mazza, Mahbubul Haque,
Muhua Pang, and Brian Curran. The research was funded by University of
Timeline: > 2 years
TRN Categories: Wireless Communications; Applied Technology
Story Type: News
Related Elements: None
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