RFID system and method for localizing and tracking a moving object with an RFID tag
First Claim
1. A radio frequency identification (RFID) system for object location and tracking comprising:
- an RFID reader for initiating a query for an RFID tag attached to an object;
an RFID tag attached to said object for responding with a first response signal to said query, said query being received directly from said RFID reader;
at least one sensor-tag for passively receiving a combined signal including said first response signal from said RFID tag and said query from said RFID reader, receipt, by said at least one sensor-tag, of said first response signal and said query is substantially simultaneous, passively demodulating said combined signal and decoding the first response signal from said RFID tag, and determining if said RFID tag is in a predetermined range of said at least one sensor-tag based on said passive demodulation and decoding;
the said at least one sensor-tag passively communicating a second response signal by using backscatter modulation to said RFID reader, based upon the determination, when said at least one sensor-tag receives a request signal from said RFID reader; and
a data processing element for processing said second response signal received from said at least one sensor-tag to determine the location of said RFID tag using a predefined calculation, a known position of said at least one sensor-tag and said predetermined range of said at least one sensor-tag.
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Accused Products
Abstract
A radio frequency identification (RFID) system and method for tracking and locating an RFID tag is disclosed. The system includes a reader, an identification tag, at least one sensor-tag and a data processing element. The reader is used to initiate a query for an object with an RFID tag. The identification tag is attached to the object. The RFID tag responds to the query. At least one sensor-tag is positioned near the RFID tag. The at least one sensor-tag functions to receive the response of the RFID tag. The sensor-tag determines whether the identification tag is within a predetermined sensor-tag range. Based upon this determination, the at least one sensor-tag communicates a response signal to the reader when the at least one sensor-tag receives a predetermined request signal from the reader. Based on the responses of the sensor-tags, the location of the object with the responding RFID tag can be calculated.
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Citations
19 Claims
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1. A radio frequency identification (RFID) system for object location and tracking comprising:
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an RFID reader for initiating a query for an RFID tag attached to an object; an RFID tag attached to said object for responding with a first response signal to said query, said query being received directly from said RFID reader; at least one sensor-tag for passively receiving a combined signal including said first response signal from said RFID tag and said query from said RFID reader, receipt, by said at least one sensor-tag, of said first response signal and said query is substantially simultaneous, passively demodulating said combined signal and decoding the first response signal from said RFID tag, and determining if said RFID tag is in a predetermined range of said at least one sensor-tag based on said passive demodulation and decoding; the said at least one sensor-tag passively communicating a second response signal by using backscatter modulation to said RFID reader, based upon the determination, when said at least one sensor-tag receives a request signal from said RFID reader; and a data processing element for processing said second response signal received from said at least one sensor-tag to determine the location of said RFID tag using a predefined calculation, a known position of said at least one sensor-tag and said predetermined range of said at least one sensor-tag. - View Dependent Claims (9, 10, 11, 12, 19)
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2. A location determination method comprising:
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(a) initiating a query for identification using a radio frequency identification (RFID) reader; (b) responding with a first response signal to said query by a radio frequency identification (RFID) tag, said query is received directly from said RFID reader; (c) receiving passively said first response signal at least one sensor-tag; (d) receiving passively said query at said at least one sensor-tag from said RFID reader, receipt, by said at least one sensor-tag, of said query and said first response signal is substantially simultaneous; (e) determining if said radio frequency identification (RFID) tag that responded to the query is within a predetermined range of said at least one sensor-tag by passively demodulating a combined signal including said query received from said RFID reader and first response signal from said RFID tag and decoding the first response signal from said RFID tag; (f) communicating passively a second response signal by using backscatter modulation based upon said determination when said at least one sensor-tag receives a request signal; and (g) determining the location of said RFID tag based upon said second response signal from said at least one sensor-tag using a predetermined method using the predetermined range of said at least one sensor-tag and a known position of said at least one sensor-tag. - View Dependent Claims (3, 4, 5, 6, 7, 8, 13, 14, 15, 16, 17, 18)
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Specification