METHOD, APPARATUS, AND SYSTEM FOR RADIO FREQUENCY IDENTIFICATION (RFID) TAG ASSOCIATION AND RELATIVE POSITIONING

• US 20090184802A1
• Filed: 01/17/2008
• Published: 07/23/2009
• Est. Priority Date: 01/17/2008
• Status: Active Grant

• Current Assignee: Intermec IP Corporation (Honeywell International Inc.)
• Original Assignee: Intermec IP Corporation (Honeywell International Inc.)
• Inventors: Park, Daniel Lewis
• Granted Patent: US 8,077,014 B2
• Time in Patent Office: Days
• US Class Current: 340/10.100
• CPC Class Codes: G06K 17/0029 the arrangement being specially adapted for wireless interrogation of grouped or bundled articles tagged with wireless record carriers
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10178 including auxiliary means for focusing, repeating or boosting the electromagnetic interrogation field comparable booster antennas integrated on the record carrier itself G06K19/07794
• CPC Class Codes: H04Q 2213/13095 PIN / Access code, authentication
• CPC Class Codes: H04Q 2213/13098 Mobile subscriber

Abstract

Obscured radio frequency identification (RFID) tags are indirectly read by an RFID reader. Other tags operate to relay the information associated with the obscured tags from one tag to another, until the associated information is ultimately received by the RFID reader from a tag in direct communication with the RFID reader. The tags may be adapted to store the received information associated with the obscured tags and then to encode this associated information and resident information in return signal(s) transmitted to the RFID reader and/or to other tag(s). The RFID reader is adapted to decode the received return signals to obtain the information encoded therein, and to process the decoded information to identify irrelevant tags and obscured tags.

Claims

1. A radio frequency identification (RFID) system, comprising:

an RFID reader adapted to provide an interrogation signal; and

a plurality of RFID tags, at least a first of said RFID tags being positioned to receive said interrogation signal and being adapted to provide at least one first return signal in response to said interrogation signal, at least a second of said RFID tags being adapted to provide a second return signal, said second return signal being encoded with information, associated with said second RFID tag, that is provided to said first RFID tag, said at least one first return signal provided by said first RFID tag being encoded with information resident in said first RFID tag and with said provided information associated with said second RFID tag,

wherein said RFID reader is adapted to decode said first return signal to obtain the resident information and associated information encoded therein, and adapted to process said decoded information to identify said second RFID tag as being positioned in indirect communication with said RFID reader.

2. The system of claim 1 wherein said associated information is distinguished from said resident information by an identification added to said associated information, said identification usable by said RFID reader to perform said identify said second RFID tag as being in indirect communication with said RFID reader.

3. The system of claim 1 wherein said second RFID tag is positioned in indirect communication with said RFID reader due to at least one or more of:

said second RFID tag being outside of a field of view of said interrogation signal, said interrogation signal being at least partially blocked from said second RFID tag, said second return signal having insufficient strength to reach said RFID reader, and said second return signal being at least partially blocked from said RFID reader.

4. The system of claim 1 wherein said first RFID tag is adapted to store said information associated with said second RFID tag.

5. The system of claim 1 wherein said RFID reader is adapted to filter out duplicate ones of said resident information and said associated information.

6. The system of claim 1 wherein said second return signal is provided by said second RFID tag to at least a third of said RFID tags, said third RFID tag being adapted to provide said associated information to said first RFID tag through a third return signal having said associated information encoded therein.

7. The system of claim 1 wherein said RFID reader is further adapted to determine, from information decoded by said RFID reader from a plurality of return signals provided by respective multiple ones of said RFID tags in response to said interrogation signals, which of said multiple ones of said RFID tags are relevant to a particular read operation and which of said multiple RFID tags are irrelevant to said read operation, said RFID tags determined to be irrelevant having a least number of communications with other RFID tags during said read operation.

8. A radio frequency identification (RFID) reader apparatus, comprising:

an antenna and transceiver circuitry adapted to provide an interrogation signal to at least some of a plurality of RFID tags and adapted to receive respective return signals from responsive ones of said RFID tags, at least one of said return signals from each responsive RFID tag being encoded with first information pertaining to the respective responsive RFID tag and second information associated with at least one other responsive RFID tag;

a decoder coupled to said transceiver circuitry to said decode said first information and said second information from each at least one return signal; and

a processor coupled to said decoder to process said decoded first information and said decoded second information to determine which of said plurality of RFID tags provided their respective at least one return signal directly to said antenna and which of said plurality of RFID tags provided their respective at least one return signal indirectly to said antenna via at least one other RFID tag.

9. The apparatus of claim 8 wherein to determine which of said plurality of RFID tags provided their respective at least one return signal indirectly to said antenna, said processor is adapted to detect a flag in said decoded second information, said flag indicating that the RFID tag associated with the decoded second information is positioned in a location insufficient to permit the at least one return signal of that RFID tag to be received by said antenna.

10. The apparatus of claim 8 wherein said processor is further adapted to filter out duplicate ones of said decoded second information.

11. The apparatus of claim 8 wherein said apparatus is further adapted to determine, collectively from all of said decoded second information, which of said plurality of RFID tags are relevant to a particular read operation and which of said plurality of RFID tags are irrelevant to said read operation, said RFID tags determined by said processor to be irrelevant having a least number of communications with other RFID tags during said read operation.

12. The apparatus of claim 11, further comprising a storage medium, coupled to said processor, to store a table adapted to be populated by said processor with indications of said communications between individual ones of the plurality of RFID tags.

13. A method for a radio frequency identification (RFID) tag, the method comprising:

storing first information in said RFID tag, said first information pertaining to said RFID tag;

receiving by said RFID tag second information associated with another RFID tag that is unable to communicate said second information directly to an RFID reader;

encoding said first information and said second information in at least one return signal; and

transmitting said at least one return signal having said first information and said second information encoded therein in response to an interrogation signal from said RFID reader.

14. The method of claim 13 wherein said at least one return signal is a single return signal having both the first information and the second information encoded therein.

15. The method of claim 13 wherein said at least one return signal are two return signals having the first information and the second information respectively encoded therein.

16. The method of claim 13, further comprising storing the received second information in said RFID tag.

17. The method of claim 13, further comprising adding an identification to said second information to indicate that said second information is associated with said another RFID tag rather than pertaining to said RFID tag.

18. A method for a radio frequency identification (RFID) reader, the method comprising:

providing an interrogation signal to at least some of a plurality of RFID tags;

in response to said provided interrogation signal, receiving respective return signals from energized ones of said RFID tags, at least one of said return signals from each energized RFID tag being encoded with first information pertaining to the respective energized RFID tag and second information associated with at least one other energized RFID tag;

decoding said first information and said second information from each at least one return signal; and

processing said decoded first information and said decoded second information to determine which of said plurality of RFID tags provided their respective at least one return signal directly to said RFID reader and which of said plurality of RFID tags provided their respective at least one return signal indirectly to said RFID reader via at least one other RFID tag.

19. The method of claim 18 wherein said determining which of said plurality of RFID tags provided their respective at least one return signal directly to said RFID reader includes detecting a flag in said decoded second information, said flag indicating that the RFID tag associated with the decoded second information is positioned in a location insufficient to permit the at least one return signal of that RFID tag to be received by said RFID reader.

20. The method of claim 18, further comprising filtering out duplicate ones of said decoded second information.

21. The method of claim 18, further comprising determining, collectively from all of said decoded second information, which of said plurality of RFID tags are relevant to a particular read operation and which of said plurality of RFID tags are irrelevant to said read operation, said RFID tags determined to be irrelevant having a least number of communications with other RFID tags during said read operation.

22. An article of manufacture, comprising:

a computer-readable medium, of a radio frequency identification (RFID) reader, encoded with computer-readable instructions that are executable by a processor of said RFID reader to communicate with a plurality of RFID tags, by;

providing an interrogation signal to at least some of said plurality of RFID tags;

in response to said provided interrogation signal, receiving respective return signals from energized ones of said RFID tags, at least one of said return signals from each energized RFID tag being encoded with first information pertaining to the respective energized RFID tag and second information associated with at least one other energized RFID tag;

decoding said first information and said second information from each at least one return signal; and

processing said decoded first information and said decoded second information to determine which of said plurality of RFID tags provided their respective at least one return signal directly to said RFID reader and which of said plurality of RFID tags provided their respective at least one return signal indirectly to said RFID reader via at least one other RFID tag.

23. The article of manufacture of claim 22 wherein to determine which of said plurality of RFID tags provided their respective at least one return signal directly to said RFID reader, said instructions are executable by said processor to:

detect a flag in said decoded second information, said flag indicating that the RFID tag associated with the decoded second information is positioned in a location insufficient to permit the at least one return signal of that RFID tag to be received by said RFID reader.

24. The article of manufacture of claim 22 wherein said computer-readable medium is further encoded with computer-readable instructions executable by said processor to:

filter out duplicate ones of said decoded second information.

25. The article of manufacture of claim 22 wherein said computer-readable medium is further encoded with computer-readable instructions executable by said processor to:

determine, collectively from all of said decoded second information, which of said plurality of RFID tags are relevant to a particular read operation and which of said plurality of RFID tags are irrelevant to said read operation, said RFID tags determined to be irrelevant having a least number of communications with other RFID tags during said read operation.