Browse Prior Art Database

Method and Apparatus for Identifying and Locating Objects

IP.com Disclosure Number: IPCOM000117677D
Original Publication Date: 1996-May-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 27K

Publishing Venue

IBM

Related People

Brady, MJ: AUTHOR [+3]

Abstract

An apparatus and a method for identifying objects carrying radio frequency transponders (tags) and for locating the tags with respect to a coordinate system are disclosed.

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Method and Apparatus for Identifying and Locating Objects

      An apparatus and a method for identifying objects carrying
radio frequency transponders (tags) and for locating the tags with
respect to a coordinate system are disclosed.

      An array of radio transmitters is arranged in one, two, or
three dimensions.  The radiation patterns of the transmitters are
overlapping circles or spheres.  If a particular tag is in the circle
of one radio, the signal will be sent to that radio and the system
will know that the tag is in that circle.  At the same time, or a
different time, a second radio will determine that the tag is in the
detection range of a second radio.  The tag will now be located in
the region where the fields of the two radios intersect.  Detection
by other radios will further refine the location of the tag.
Additionally, the power of the radios may be varied so as to increase
or decrease the  range of the radios to give a range estimate in
order to further refine  the tag location.  Readings taken over a
period of time can be used to  establish the direction of travel of
the tag and the tag carrying object.