Radio frequency identification system and related operating methods

• US 8,953,570 B2
• Filed: 11/23/2010
• Issued: 02/10/2015
• Est. Priority Date: 11/23/2010
• Status: Active Grant

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Lin, Lang, Khade, Deepak, Harischandra, Chandrashekhara
• Primary Examiner(s): HALIYUR, VENKATESH N
• Application Number:
  US12/953,078
• Publication Number:
  US 20120127976A1
• Time in Patent Office: 1,540 Days
• Field of Search: 370228-356
• US Class Current: 370/338
• CPC Class Codes: G01S 13/82 wherein continuous-type signals are transmitted
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G06K 17/0022 arrangements or provisious for transferring data to distant stations, e.g. from a sensing device "transfer between computer elements G06F13/00 "; data-transmission H04L

Abstract

A method of operating a radio frequency identification (RFID) system is provided. The method interrogates RFID tags with an RFID reader and provides at least some of the collected tag data to a mobile device that is unable to communicate with RFID tags using the over-the-air interface. In some situations, the RFID system obtains the current location of the mobile device and determines the location of a target tag relative to the current location of the mobile device. Locating the target tag in this manner involves the interrogation of a reference tag located at the mobile device, along with the target tag, using one RFID reader. The position of the target tag relative to the reference tag is calculated in response to the tag response signals obtained from the target and reference tags. Moreover, location of the target tag can be independently determined relative to the location of a mobile reader, by using a reference tag attached to a fixed reader or to the mobile reader.

Claims

1. A method of operating a radio frequency identification (RFID) system, the method comprising:

generating an RFID interrogation signal with an RFID reader of the RFID system;

obtaining, in response to generating the RFID interrogation signal, at least one RFID tag response signal at the RFID reader, the at least one RFID tag response signal conveying tag data, and being received through a first network at a stationary controller; and

providing at least some of the tag data to a mobile device through a second network;

receiving, from the mobile device, a request to locate a particular item of interest having a target RFID tag associated therewith, wherein the at least one RFID tag response signal conveys tag data for the particular item of interest;

determining a location of the target RFID tag relative to the mobile device; and

presenting indicia of the determined location of the target RFID tag at the mobile device;

interrogating the target RFID tag to obtain a first tag response signal, wherein the RFID reader interrogates the target RFID tag;

interrogating a reference RFID tag located at the mobile device to obtain a second tag response signal, wherein the RFID reader interrogates the reference RFID tag; and

calculating a position of the target RFID tag relative to the reference RFID tag, wherein the position is calculated based on the first and second tag response signals.

2. The method of claim 1, wherein the mobile device is unable to interrogate RFID tags using an RFID over-the-air interface.

3. The method of claim 1, wherein the mobile device is unable to receive RFID tag response signals using an RFID over-the-air interface.

4. The method of claim 1, wherein the providing step comprises sending at least some of the tag data from an RFID system controller of the RFID system.

5. The method of claim 1, wherein the providing step comprises wirelessly transmitting at least some of the tag data from a wireless local area network infrastructure device to the mobile device.

6. The method of claim 1, wherein the providing step comprises sending at least some of the tag data to a data communication network for routing to the mobile device.

7. The method of claim 1, further comprising presenting indicia of at least some of the tag data at the mobile device.

8. The method of claim 1, further comprising:

obtaining a current location of the mobile device; and

filtering the tag data based on the current location of the mobile device to obtain filtered tag data, wherein the at least some of the tag data corresponds to the filtered tag data.

9. The method of claim 1, wherein the calculating step calculates a distance between the target RFID tag and the reference RFID tag.

10. The method of claim 1, wherein the calculating step calculates an angle of separation between the target RFID tag and the RFID reader, as measured from the reference RFID tag.

11. The method of claim 1, further comprising:

obtaining a current location of the mobile device; and

identifying the RFID reader from a plurality of RFID readers in the RFID system, based on the current location of the mobile device.

12. A method of operating a radio frequency identification (RFID) system, the method comprising:

receiving a request through a first network to locate a particular item of interest having a target RFID tag associated therewith, the request originating at a mobile device;

in response to receiving the request, interrogating the target RFID tag with an RFID reader of the RFID system to obtain an RFID tag response signal through a second network from the target RFID tag;

obtaining a current location of the mobile device; and

determining a location of the target RFID tag relative to the current location of the mobile device;

interrogating the target RFID tag with the RFID reader to obtain a first tag response signal;

interrogating a reference RFID tag located at the mobile device to obtain a second tag response signal, wherein the RFID reader interrogates the reference RFID tag; and

calculating a position of the target RFID tag relative to the reference RFID tag, wherein the position is calculated based on the first and second tag response signals.

13. The method of claim 12, further comprising providing the determined location of the target RFID tag to the mobile device.

14. The method of claim 12, wherein obtaining the current location of the mobile device comprises receiving current self-position data from the mobile device.

15. A method of operating a radio frequency identification (RFID) system, the method comprising:

receiving a request through a first network to locate a particular item of interest having a target RFID tag associated therewith, the request originating at a mobile device;

in response to receiving the request, interrogating the target RFID tag with an RFID reader of the RFID system to obtain an RFID tag response signal through a second network from the target RFID tag;

obtaining a current location of the mobile device; and

determining a location of the target RFID tag relative to the current location of the mobile device;

wherein determining the location of the target RFID tag comprises;

interrogating the target RFID tag with a first RFID reader of the RFID system to obtain a first tag response signal;

interrogating a reference RFID tag located at a second RFID reader of the RFID system to obtain a second tag response signal, wherein the first RFID reader interrogates the reference RFID tag;

obtaining, at the first RFID reader, a distance between the target RFID tag and the second RFID reader, wherein the distance is determined in response to the second RFID reader interrogating the target RFID tag; and

calculating a location of the target RFID tag based on the first tag response signal, the second tag response signal, and the obtained distance.