RFID reader location self-discovery

• US 9,563,793 B2
• Filed: 07/23/2015
• Issued: 02/07/2017
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Walmart Apollo, LLC (WalMart Inc.)
• Original Assignee: Wal-Mart Stores Texas LLC (WalMart Inc.)
• Inventors: Jones, Nicholaus Adam, Taulbee, Alvin Scott
• Primary Examiner(s): BEE, ANDREW W.
• Application Number:
  US14/807,351
• Publication Number:
  US 20160026834A1
• Time in Patent Office: 565 Days
• US Class Current: 1/1
• CPC Class Codes: G01S 1/68 Marker, boundary, call-sign, or like beacons transmitting signals not carrying directional information
• CPC Class Codes: G01S 13/765 with exchange of information between interrogator and responder
• CPC Class Codes: G01S 5/0284 Relative positioning
• CPC Class Codes: G01S 5/0289 of multiple transceivers, e.g. in ad hoc networks
• CPC Class Codes: G06K 17/00 Methods or arrangements for effecting co-operative working between equipments covered by two or more of main groups G06K1/00 - G06K15/00, e.g. automatic card files incorporating conveying and reading operations
• CPC Class Codes: G06K 7/10009 sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
• CPC Class Codes: G06K 7/10099 the directional field being used for pinpointing the location of the record carrier, e.g. for finding or locating an RFID tag amongst a plurality of RFID tags, each RFID tag being associated with an object, e.g. for physically locating the RFID tagged object in a warehouse
• CPC Class Codes: G06K 7/10356 using a plurality of antennas, e.g. configurations including means to resolve interference between the plurality of antennas

Abstract

A system and method of determining the location of a RFID reader is disclosed. The system comprises a first RFID reader, and at least one other RFID reader, and a processor. The RFID readers associate unique RFID tag information with at least one antenna that reads the information. The processor receives RFID data from the first RFID reader and the at least one other RFID reader and determines the location of the first RFID reader relative to the at least one other RFID reader based on the association of unique RFID tag information with at least one antenna of at least two readers.

Claims

1. A method of determining a location or an orientation of an RFID reader comprising:

receiving first RFID data from a first RFID reader comprising at least one antenna, wherein the first RFID data associates first tag information with at least one antenna of the first RFID reader in response to the at least one antenna of the first RFID reader reading the first tag information that uniquely identifies a first RFID tag;

receiving second RFID data from a second RFID reader having at least one antenna, wherein the second RFID data associates the first tag information with the at least one antenna of the second RFID reader in response to the at least one antenna of the second RFID reader reading the first tag information; and

determining at least one of a location or an orientation of the first RFID reader relative to the second RFID reader with a processor based on the associations in the first and the second RFID data.

2. The method of claim 1, further comprising:

locating the first and the second RFID readers in an overhead position.

3. The method of claim 1, further comprising:

determining the orientation of the first and the second RFID readers.

4. The method of claim 1, further comprising:

identifying the at least one antenna of the first RFID reader and the at least one antenna of the second RFID reader associated with a second tag information that uniquely identifies a second RFID tag.

5. The method of claim 1, further comprising:

determining an internal boundary of the facility based on the first and second RFID data.

6. The method of claim 5, further comprising:

wherein determining the at least one of the location or the orientation of the first RFID reader relative to the second RFID reader based on the associations in the first and the second RFID data is repeated over a duration of time.

7. The method of claim 1, further comprising:

determining properties of the first RFID tag.

8. The method of claim 1, further comprising:

receiving third RFID data from a third RFID reader having at least one antenna, wherein the third RFID data associates second tag information with the at least one antenna of the third RFID data in response to the third RFID reader reading the second tag information that uniquely identifies at least one other RFID tag; and

determining at least one of a location or an orientation of the first RFID reader relative to the second RFID reader and the third RFID reader based on the associations in the first, the second, and the third RFID data.

9. The method of claim 8, further comprising:

determining a quantity of RFID tags based on the first RFID data, the second RFID data, and the third RFID data.

10. A system for determining a location or an orientation of a RFID reader comprising:

a first RFID reader having at least one antenna configured to generate first RFID data, wherein the first RFID data associates first tag information with the at least one antenna of the first RFID reader in response to the at least one antenna of the first RFID reader reading the first tag information that uniquely identifies a first RFID tag;

a second RFID reader having at least one antenna configured to generate second RFID data, wherein the second RFID data associates the first tag information with the at least one antenna of the second RFID reader in response to the at least one antenna of the second RFID reader reading the first tag information;

a processor configured to receive the first RFID data and the second RFID data and to determine at least one of a location or an orientation of the first RFID reader relative to the second RFID reader based on associations in the first RFID data and the second RFID data.

11. The system of claim 10, further comprising:

a third RFID reader having at least one antenna configured to generate third RFID data, wherein the third RFID data associates the first tag information with the at least one antenna of the third RFID reader in response to the at least one antenna of the third RFID reader reading the first tag information; and

wherein the processor is further configured to receive the third RFID data and to determine at least one of a location or an orientation of the first RFID reader relative to the second RFID reader and the third RFID reader based on associations in the first RFID data, the second RFID data, and the third RFID data.

12. The system of claim 10, wherein the first RFID reader includes a plurality of the antennas that are distributed 360°

around the first RFID reader.

13. The system of claim 10, wherein the first RFID reader is arranged in an overhead position.

14. The system of claim 10, wherein the processor is further configured to determine an internal boundary of a facility based on the first RFID data and the second RFID data.

15. The system of claim 10, wherein the processor is further configured to periodically compare the first RFID data and the second RFID data.

16. The system of claim 10, wherein the first RFID reader generates a third RFID data, wherein the third RFID data associates second tag information with the at least one antenna of the first RFID reader in response to the at least one antenna of the first RFID reader reading the second tag information that uniquely identifies at least one other RFID tag.

17. The system of claim 16, wherein the processor is further configured to compare the first RFID data, the second RFID data and the third RFID data based on a property of the first RFID tag and the second RFID tag.

18. The system of claim 16, wherein the processor is further configured to compare the first RFID data, the second RFID data and the third RFID data based on a quantity of RFID tags.

19. A non-transitory computer readable medium comprising instructions configured to cause a computer processor to execute a method comprising:

receiving first RFID data from a first RFID reader comprising at least one antenna, wherein the first RFID data associates first tag information with the at least one antenna of the first RFID reader in response to the at least one antenna of the first RFID reader reading the first tag information that uniquely identifies a first RFID tag;

receiving second RFID data from a second RFID reader having at least one antenna, wherein the second RFID data associates the first tag information with the at least one antenna of the second RFID reader in response to the at least one antenna of the second RFID reader reading the first tag information; and

determining at least one of a location or an orientation of the first RFID reader relative to the second RFID reader based on the associations in the first and the second RFID data.

20. The medium of claim 19, wherein execution of the instructions by the computer processor cause the computer processor to determine an internal boundary of the facility based on the first and second RFID data.