Management of inventory items

• US 9,928,481 B1
• Filed: 06/16/2016
• Issued: 03/27/2018
• Est. Priority Date: 12/02/2014
• Status: Active Grant

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Inventors: Russell, Ryan Scott, Ryle, Thomas Matthew, Lauka, Wesley Scott, Phillips, Jonathan David, Wood, James Hollis
• Primary Examiner(s): Vo, Tuyen K
• Application Number:
  US15/184,952
• Time in Patent Office: 649 Days
• Field of Search: 235385
• CPC Class Codes: G06K 19/07758 arrangements for adhering the record carrier to further objects or living beings, functioning as an identification tag
• 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
• 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

In some examples, a reader system is provided for managing inventory items in an inventory system. The reader system may be configured to read tags associated with items stowed in an inventory holder. The inventory holder may be detachably coupled to a mobile drive unit. The mobile drive unit may move the inventory holder to a first position near an antenna of the reader system and the tags may begin to be read. While reading or at other times in the reading process, the mobile drive unit may move the inventory holder relative to the antenna. The identified tags may be compared to a manifest list of items expected to be stowed in the inventory holder.

Claims

1. A computer-implemented method, comprising:

transmitting a radio frequency transmission via an antenna in a direction of a holder, the holder detachably coupled to a mobile drive unit, the mobile drive unit configured to lift and transport the holder;

receiving, by a reader that is separate from the mobile drive unit, radio frequency responses via the antenna, the radio frequency responses provided by one or more identifying tags in response to the radio frequency transmission, each identifying tag associated with an item stowed in the holder;

identifying, based at least in part on the radio frequency responses, items stowed in the holder with respect to a manifest of expected items that are expected to be stowed in the holder;

instructing movement of the holder relative to the antenna by the mobile drive unit at least until a threshold percentage of the expected items has been identified, wherein the receiving of the radio frequency responses and the identifying of the items stowed occur at least partly during the movement of the holder by the mobile drive unit, and wherein the movement exposes different sides of the holder to the antenna; and

instructing stopping of the holder by the mobile drive unit after the threshold percentage of the expected items has been identified.

2. The computer-implemented method of claim 1, wherein threshold percentage indicates that a predetermined percentage of the expected items have been identified as the items stowed in the holder.

3. The computer-implemented method of claim 1, further comprising

providing a notification when the threshold percentage of expected items has not been met after a predetermined time.

4. The computer-implemented method of claim 1, wherein the one or more identifying tags comprise unique identifying tags and each unique identifying tag is attached to and uniquely identifies a particular item stowed in the holder.

5. A computer-implemented method, comprising:

reading, via an antenna and with respect to a manifest of expected items, a first portion of a plurality of identifying tags associated with a plurality of items to identify a first portion of the plurality of items when a holder is located at a first position relative to the antenna, the plurality of items being located within the holder;

instructing a mobile drive unit to move the holder from the first position to a second position in a manner that exposes different sides of the holder to the antenna;

at least while the mobile drive unit moves the holder to the second position relative to the antenna, reading, via the antenna and at least until a threshold percentage of the expected items has been identified, a second portion of the plurality of identifying tags associated with the plurality of items to identify a second portion of the plurality of items, the mobile drive unit configured to lift and transport the holder, wherein the antenna is separate from the mobile drive unit;

instructing stopping of the holder by the mobile drive unit after the threshold percentage of the expected items has been identified; and

providing at least a portion of inventory information to an inventory management system, the portion of the inventory information at least including the identified portions of the plurality of items.

6. The computer-implemented method of claim 5, further comprising:

instructing the mobile drive unit to move the holder to the first position prior to reading the first portion of the plurality of identifying tags; and

prior to instructing stopping of the holder, reading a third portion of the plurality of identifying tags associated with the plurality of items to identify a third portion of the plurality of items at least after the mobile drive unit has moved the holder from the first position to the second position.

7. The computer-implemented method of claim 5, wherein the reading at the first position and the reading at the second position are performed when the holder is detachably coupled to the mobile drive unit.

8. The computer-implemented method of claim 5, further comprising:

determining, based at least in part on the reading of the portions of the plurality of identifying tags, a set of identified items, the set of identified items including items whose associated identifying tags have been identified;

accessing the manifest of expected items from the inventory management system; and

comparing the set of identified items with the manifest of expected items to determine a set of missing items.

9. The computer-implemented method of claim 8, further comprising determining a completion of the reading of the plurality of identifying tags when the set of missing items includes a quantity of items below the threshold percentage.

10. The computer-implemented method of claim 5, further comprising determining a completion of the reading of the plurality of identifying tags in accordance with a confidence threshold indicating a confidence level that all identifying tags in the holder have been read.

11. The computer-implemented method of claim 5, further comprising determining a completion of the reading of the plurality of identifying tags in accordance with a time threshold indicating a period of time during which the reading of the plurality of identifying tags will be performed.

12. The computer-implemented method of claim 5, wherein the plurality of identifying tags comprise unique identifying tags and each unique identifying tag is attached to and uniquely identifies a particular item of the plurality of items.

13. The computer-implemented method of claim 5, wherein:

the portion of the inventory information includes a first portion and a second portion;

the first portion of the inventory information identifies a first set of items corresponding to the first portion of the plurality of identifying tags; and

the second portion of the inventory information identifies a second set of items corresponding to the second portion of the plurality of identifying tags, at least part of the first portion of the inventory information provided to the inventory management system before the mobile drive unit moves the holder to the second position.

14. The computer-implemented method of claim 5, wherein the reading of the plurality of identifying tags includes:

transmitting a radio frequency transmission via the antenna in a direction of the holder;

receiving, by at least one reader, radio frequency responses via the antenna, the radio frequency responses provided by the plurality of identifying tags in response to the radio frequency transmission; and

identifying, based at least in part on the radio frequency responses, the plurality of items stowed in the holder.

15. The computer-implemented method of claim 5, further comprising generating a report indicating one or more items of the expected items that were not identified by the reading of the plurality of identifying tags.

16. A system, comprising:

an antenna; and

a reader in communication with the antenna, the reader configured to;

read, via the antenna and with respect to a manifest of expected items that are expected to be stowed in a holder, a first tag identifying a first item, the first item stowed in the holder that is detachably coupled to a mobile drive unit, the mobile drive unit configured to lift and transport the holder, wherein the reader is separate from the mobile drive unit;

read, via the antenna and at least until a threshold percentage of the expected items has been identified, other tags identifying other items in response to the mobile drive unit adjusting an orientation of the holder relative to the antenna in a manner that exposes different sides of the holder to the antenna, the other items stowed in the holder; and

cease reading, via the antenna, after the threshold percentage of expected items has been read and in response to the mobile drive unit receiving an instruction to cease adjusting the orientation of the holder relative to the antenna.

17. The system of claim 16, wherein ceasing reading comprises ceasing reading in accordance with a confidence threshold.

18. The system of claim 17, wherein ceasing reading in accordance with the confidence threshold comprises ceasing reading after lapse of a period of time corresponding to the confidence threshold.

19. The system of claim 17, wherein ceasing reading in accordance with the confidence threshold comprises ceasing reading after receiving a different instruction to stop reading, the different instruction determined based at least in part on a comparison of tag information with item information corresponding to items of the holder.

20. The system of claim 16, wherein the mobile drive unit adjusting the orientation of the holder relative to the antenna comprises the mobile drive unit rotating the holder about a rotation axis substantially parallel to a vertical dimension of the holder.