Efficient shuffling of mobile drive units for inventory holders

• US 9,067,317 B1
• Filed: 12/19/2014
• Issued: 06/30/2015
• Est. Priority Date: 09/09/2013
• Status: Active Grant

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Inventors: Wurman, Peter R., Verminski, Matthew David, Mountz, Michael Cordell
• Primary Examiner(s): Crawford, Gene
• Assistant Examiner(s): LOGAN, KYLE O
• Application Number:
  US14/576,561
• Time in Patent Office: 193 Days
• Field of Search: 700/216
• US Class Current: 1/1
• CPC Class Codes: B25J 9/1602 characterised by the control system, structure, architecture
• CPC Class Codes: B65G 1/1373 for fulfilling orders in warehouses
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G06Q 10/08 Logistics, e.g. warehousing, loading or distribution; Inventory or stock management
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders
• CPC Class Codes: Y10S 901/01 Mobile robot

Abstract

A mobile drive unit that freely and independently moves about a facility to transport inventory holders. The mobile drive unit may operate through communications with other drive units, or under a more centralized control of a management module. For various operating scenarios, the mobile drive unit is directed to shuffle the inventory holders in a manner that minimizes travel of the mobile drive unit, thereby improving overall system efficiency. One or more mobile drive units may be used to transport inventory holders to and from a region, and to sequentially reposition or slide each of the inventory holders within the region according to a priority ordering.

Claims

1. A mobile drive unit comprising:

a drive component; and

a control unit configured to generate control instructions for the drive component based at least in part on a predefined shuffle process, the control instructions are configured to cause the drive component to;

retrieve a new inventory holder from a storage location;

temporarily place the new inventory holder in a temporary staging location of a region of a warehouse, the region including a pick station;

reposition a first inventory holder from a first pick location within the region to the temporary staging location upon the first inventory holder attaining a completion status;

subsequently position a second inventory holder from a second pick location into the first pick location vacated by repositioning the first inventory holder;

transport the first inventory holder away from the temporary staging location; and

reposition the new inventory holder from the temporary staging location to the second pick location or a third pick location.

2. The mobile drive unit as recited in claim 1, wherein the control instructions further cause the drive component to initially place the second inventory holder in a temporary location while the first inventory holder is repositioned from the first pick location to the temporary staging location.

3. The mobile drive unit as recited in claim 1, wherein the control instructions further cause the drive component to initially reposition the second inventory holder from an original location to a temporary location in order to clear a path from the second pick location to the first pick location.

4. The mobile drive unit as recited in claim 1, wherein the control instructions further cause the drive component to initially retrieve the second inventory holder from another region of the warehouse and temporarily position the second inventory holder in a temporary location while the first inventory holder is repositioned from the first pick location to the temporary staging location.

5. The mobile drive unit as recited in claim 1, wherein the temporary staging location is proximal to the first pick location.

6. The mobile drive unit as recited in claim 1, wherein the second pick location is adjacent to the first pick location.

7. The mobile drive unit as recited in claim 1, wherein the control unit comprises memory configured to store shuffle instructions that are based at least in part on the predefined shuffle process, the shuffle instructions configured to control operation of the drive component.

8. A mobile drive unit comprising:

a drive component;

a communication unit configured to receive drive instructions based at least in part on a predefined shuffle process; and

a control unit configured to operate the drive component based at least in part on the received drive instructions, the drive instructions configured to cause the drive component to;

retrieve a new inventory holder from a storage location and temporarily place the new inventory holder in a temporary staging location of a region of a warehouse, the region including a pick station;

reposition a first inventory holder from a first pick location within the region to the temporary staging location within the region upon the first inventory holder attaining a completion status;

subsequently position a second inventory holder from a second pick location into the first pick location vacated by repositioning the first inventory holder;

transport the first inventory holder away from the temporary staging location; and

reposition the new inventory holder from the temporary staging location to the second pick location or a third pick location.

9. The mobile drive unit as recited in claim 8, wherein the drive instructions further cause drive component to initially reposition the second inventory holder in a temporary location while the first inventory holder is repositioned from the first pick location to the temporary staging location.

10. The mobile drive unit as recited in claim 8, wherein the drive instructions further cause the drive component to initially reposition the second inventory holder from an original location to a temporary location in order to clear a path from the second pick location to the first pick location.

11. The mobile drive unit as recited in claim 8, wherein the drive instructions further cause the drive component to initially retrieve the second inventory holder from another region of the warehouse and temporarily position the second inventory holder in a temporary location while the first inventory holder is repositioned from the first pick location to the temporary staging location.

12. The mobile drive unit as recited in claim 8, wherein the temporary staging location is proximal to the first pick location.

13. The mobile drive unit as recited in claim 8, wherein the second pick location is adjacent to the first pick location.

14. The mobile drive unit as recited in claim 8, wherein the predefined shuffle process is based at least on a layout of the warehouse.

15. A mobile drive unit comprising:

a drive component; and

a control unit configured to instruct the drive component to shuffle a first inventory holder, a second inventory holder, and a third inventory holder within a warehouse according to a predefined shuffle process, wherein the first inventory holder is positioned at a first pick location of a pick station, the second inventory holder is positioned at a second pick location of the pick station, and the third inventory holder is positioned at a third pick location of the pick station, the control unit instructs the drive component to;

retrieve a new inventory holder and deposit the new inventory holder in a first holding location;

move the first inventory holder from the first pick location to a second holding location upon the first inventory holder attaining a complete status;

subsequently move the second inventory holder from the second pick location into the first pick location vacated by the first inventory holder;

subsequently move the third inventory holder from the third pick location into the second pick location vacated by the second inventory holder; and

subsequently move the first inventory holder away from the second holding location to remove the first inventory holder from the pick station.

16. The mobile drive unit as recited in claim 15, wherein the control unit instructs the drive component to subsequently move the new inventory holder into the third pick location vacated by the third inventory holder.

17. The mobile drive unit as recited in claim 15, wherein the first holding location and the second holding location are located adjacent to each other and are separate from the first pick location, the second pick location, and the third pick location.

18. The mobile drive unit as recited in claim 15, wherein the first holding location and the second holding location are located within the pick station.

19. The mobile drive unit as recited in claim 15, wherein the predefined shuffle process is based at least on a physical layout of the warehouse.

20. The mobile drive unit as recited in claim 15, further comprising an antenna configured to allow communication with at least one of a shuffle process management system or another mobile drive unit.