Pick verification using moving RFID tags

• US 9,830,485 B1
• Filed: 10/03/2016
• Issued: 11/28/2017
• Est. Priority Date: 08/25/2014
• Status: Active Grant

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Inventors: Lecky, Ned
• Primary Examiner(s): Le, Thien M
• Assistant Examiner(s): Taylor, April
• Application Number:
  US15/283,487
• Time in Patent Office: 421 Days
• CPC Class Codes: G06K 7/10128 the step consisting of detection of the presence of one or more record carriers in the vicinity of the interrogation device
• CPC Class Codes: G06K 7/10366 the interrogation device being adapted for miscellaneous applications
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders
• CPC Class Codes: G06Q 10/0875 Itemisation or classification of parts, supplies or services, e.g. bill of materials

Abstract

Disclosed are various embodiments for pick verification using moving radio frequency identification (RFID) tags. A robotic picker moves an item storage structure within range of a radio frequency identification (RFID) tag reader, wherein the item storage structure comprises multiple items and the items each have an RFID tag affixed. The RFID tag reader emits an electric field. The robotic picker moves the item storage structure while the RFID tag reader emits the electric field. An RFID tag identification device receives responses from energized RFID tags affixed to the items. The RFID tag identification device determines that an energized RFID tag is in motion and selects an identifier broadcast by the energized RFID tag that is in motion.

Claims

1. A system, comprising:

a robotic picker configured to move an item storage structure containing a plurality of items, wherein individual ones of the plurality of items have a radio frequency identification (RFID) tag affixed; and

an RFID tag identification device configured to;

energize a plurality of RFID tags affixed to respective ones of the plurality of items;

receive a respective plurality of responses from respective ones of the plurality of RFID tags, each of the respective plurality of responses from the respective ones of the plurality of RFID tags comprising velocity data for the respective ones of the plurality of RFID tags;

determine that a particular RFID tag within the plurality of RFID tags is in motion based at least in part on the velocity data in a respective response received from the particular RFID tag; and

determine an identifier for the particular RFID tag.

2. The system of claim 1, wherein, to determine that the particular RFID tag is in motion, the RFID tag identification device is further configured to receive acceleration data from the particular RFID tag, wherein the acceleration data indicates that the particular RFID tag is moving.

3. The system of claim 1, wherein, to determine that the particular RFID tag is in motion, the RFID tag identification device is further configured to detect a change in an electric field strength of the particular RFID tag.

4. The system of claim 1, wherein:

the RFID tag identification device further comprises an RFID reader; and

the robotic picker is further configured to rotate the item storage structure in place within range of the RFID reader.

5. The system of claim 1, wherein the identifier comprises a first identifier and the system further comprises a computing device in network communication with the RFID tag identification device, the computing device comprising a processor, a memory, and machine readable instructions stored in the memory that, when executed by the processor, cause the computing device to determine that the first identifier for the particular RFID tag matches a second identifier of an item located in the item storage structure.

6. The system of claim 1, wherein the identifier is a first identifier and the system further comprises a computing device in network communication with the RFID tag identification device, the computing device comprising a processor, a memory, and machine readable instructions stored in the memory that, when executed by the processor, cause the computing device to determine that the first identifier for the particular RFID tag matches a second identifier of an item included in a pick list associated with the robotic picker.

7. A system, comprising:

a robotic picker configured to move an item storage structure containing a plurality of items, wherein individual ones of the plurality of items have a radio frequency identification (RFID) tag affixed; and

an RFID tag identification device configured to;

energize a plurality of RFID tags comprising the plurality of RFID tags affixed to respective ones of the plurality of items;

receive a respective plurality of responses from respective ones of the plurality of RFID tags, each of the respective plurality of responses including acceleration data for the respective ones of the plurality of RFID tags, wherein the acceleration data indicates whether the respective ones of the plurality of RFID tags are in motion;

determine that a particular RFID tag within the plurality of RFID tags is in motion based at least in part on the acceleration data included in a respective response received from the particular RFID tag;

determine a first identifier for the particular RFID tag; and

send the first identifier to a computing device; and

the computing device being in network communication with the RFID tag identification device, wherein the computing device comprises a processor, a memory, and machine readable instructions stored in the memory that, when executed by the processor, cause the computing device to determine that the first identifier for the particular RFID tag matches a second identifier for an item on a pick list.

8. The system of claim 7, wherein the pick list is associated with the robotic picker.

9. The system of claim 8, wherein, to determine that the particular RFID tag is in motion, the RFID tag identification device is further configured to receive velocity data from the particular RFID tag, wherein the velocity data indicates that the particular RFID tag is moving.

10. The system of claim 9, wherein:

the RFID tag identification device further comprises an RFID reader; and

the robotic picker is further configured to rotate the item storage structure in place within range of the RFID reader.

11. The system of claim 7, wherein, to determine that the particular RFID tag is in motion, the RFID tag identification device is further configured to detect a change in an electric field strength of the particular RFID tag.

12. The system of claim 7, wherein:

the RFID tag identification device further comprises an RFID reader; and

the robotic picker is further configured to rotate the item storage structure around the RFID reader.

13. The system of claim 7, wherein the machine readable instructions of the computing device, when executed by the processor, further cause the computing device to determine that the item in the pick list is located in the item storage structure based at least in part on a match of the first identifier to the second identifier.

14. A method, comprising:

moving, with a robotic picker, an item storage structure within range of a radio frequency identification (RFID) tag reader, wherein the item storage structure comprises a plurality of items and individual ones of the plurality of items have an RFID tag affixed;

emitting, from a RFID tag reader, an electric field;

moving, with the robotic picker, the item storage structure while the RFID tag reader emits the electric field;

receiving, with an RFID tag identification device, responses from a plurality of energized RFID tags affixed to the plurality of items;

detecting, with the RFID tag identification device, a change in an electric field strength of each one of the plurality of energized RFID tags affixed to the plurality of items;

determining, with the RFID tag identification device, that a particular energized RFID tag from the plurality of energized RFID tags is in motion based at least in part on the change in the electric field strength of the particular energized RFID tag; and

selecting, with the RFID tag identification device, an identifier broadcast by the particular energized RFID tag that is in motion.

15. The method of claim 14, further comprising determining that an item is located within the item storage structure based at least in part on the identifier broadcast by particular energized RFID tag that is in motion.

16. The method of claim 14, wherein determining that the particular energized RFID tag is in motion further comprises receiving velocity data from the particular energized RFID tag, wherein the velocity data indicates that the particular energized RFID tag is moving.

17. The method of claim 14, wherein determining that the particular energized RFID tag is in motion further comprises receiving acceleration data from the particular energized RFID tag, wherein the acceleration data indicates that the particular energized RFID tag is moving.

18. The method of claim 14, wherein moving the item storage structure while the RFID tag reader emits the electric field further comprises rotating in place, with the robotic picker, the item storage structure.

19. The method of claim 14, wherein moving the item storage structure while the RFID tag reader emits the electric field further comprises moving, with the robotic picker, the item storage structure around the RFID tag identification device.

20. The method of claim 14, further comprising sending, from the RFID tag identification device, the identifier to a remote computing device to determine that at least one of the plurality of items associated with the particular energized RFID tag is included in a pick list.