Re-arrange stored inventory holders

• US 9,452,883 B1
• Filed: 09/26/2014
• Issued: 09/27/2016
• Est. Priority Date: 09/26/2014
• Status: Active Grant

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Inventors: Farwaha, Pardeep Singh, Holt, Ryan Alexander, Glazkov, Alex, Holcomb, Jared Brian, Wurman, Peter R., Brazeau, Jeremiah David, Durham, Joseph W., Enright, John Joseph
• Primary Examiner(s): Logan, Kyle
• Application Number:
  US14/499,047
• Time in Patent Office: 732 Days
• Field of Search: 700/218
• US Class Current: 1/1
• CPC Class Codes: B65G 1/0492 with cars adapted to travel in storage aisles
• CPC Class Codes: B65G 1/10 with relatively movable racks to facilitate insertion or removal of articles cabinets with means for moving compartments up and down A47B51/00; cabinet system, e.g. consisting of cabinets arranged in a row with means to open or close passages between adjacent cabinets A47B53/02
• CPC Class Codes: B65G 1/137 with arrangements or automatic control means for selecting which articles are to be removed
• CPC Class Codes: G05B 13/026 using a predictor
• CPC Class Codes: G05D 1/0287 involving a plurality of land vehicles, e.g. fleet or convoy travelling traffic control systems for road vehicles G08G1/00, particularly anticollision systems G08G1/16
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders

Abstract

Inventory holders in an inventory system can be moved among differing storage positions. The moves can be performed by mobile drive units not otherwise transporting inventory holders directly to or from inventory stations. A free mobile drive unit can move an inventory holder not likely to be useful soon at any nearby station from a storage position near the station to a position farther away from the station. A mobile drive unit can move an inventory holder likely to be useful soon from a storage position farther away from one or more stations to a storage position nearby one or more stations.

Claims

1. An inventory management system, comprising:

inventory holders configured to store inventory items;

mobile drive units configured to move the inventory holders;

a station configured for performance of a task related to one or more inventory items associated with an inventory holder when the inventory holder is positioned at the station;

storage locations, each storage location for storing an inventory holder apart from the station when the inventory holder is not at the station, not being transported en route to the station, and not being transported en route from the station; and

a management module configured to;

access a designated set of tasks comprising tasks designated for performance at the station;

instruct a first set of the mobile drive units to move respective inventory holders of a first set of inventory holders from respective storage locations to the station, the respective inventory holders of the first set of inventory holders meeting criteria of respective tasks of the designated set of tasks;

determine a predicted set of tasks comprising tasks predicted to be designated for performance at the station; and

instruct a second set of the mobile drive units to move respective inventory holders of a second set of inventory holders from respective initial storage locations to respective subsequent storage locations closer to the station, the respective inventory holders of the second set of inventory holders meeting criteria of respective tasks of the predicted set of tasks.

2. The inventory management system of claim 1, wherein the management module is further configured to instruct a third set of the mobile drive units to move respective inventory holders of a third set of inventory holders from respective initial storage locations to respective subsequent storage locations further from the station, the inventory holders of the third set of inventory holders not meeting criteria of respective tasks of the predicted set of tasks.

3. The inventory management system of claim 1, wherein the station is a stow station for loading inventory items into the inventory holders;

wherein the predicted set of tasks determined by the management module comprises stowing tasks of loading inventory items into the inventory holders; and

wherein the management module is configured to instruct the second set of the mobile drive units to move respective inventory holders having open space for the stowing tasks from respective initial storage locations to respective subsequent storage locations closer to the stow station.

4. The inventory management system of claim 3, wherein the management module is further configured to instruct a third set of the mobile drive units to move respective inventory holders lacking open space for the stowing tasks from respective initial storage locations to respective subsequent storage locations further from the stow station.

5. The inventory management system of claim 1, wherein the station is a count station for counting inventory items of the inventory holders;

wherein the predicted set of tasks determined by the management module comprises counting tasks of counting inventory items of the inventory holders; and

wherein the management module is configured to instruct the second set of the mobile drive units to move respective inventory holders having inventory bins with inventory items therein to be counted for the counting tasks from respective initial storage locations to respective subsequent storage locations closer to the count station.

6. The inventory management system of claim 5, wherein the management module is further configured to instruct a third set of the mobile drive units to move respective inventory holders lacking inventory bins with inventory items therein to be counted for the counting tasks from respective initial storage locations to respective subsequent storage locations further from the count station.

7. The inventory management system of claim 1, wherein the station is a pick station for unloading inventory items from the inventory holders;

wherein the predicted set of tasks determined by the management module comprises picking tasks of unloading inventory items from the inventory holders; and

wherein the management module is configured to instruct the second set of the mobile drive units to move respective inventory holders having inventory items for the picking tasks from respective initial storage locations to respective subsequent storage locations closer to the pick station.

8. The inventory management system of claim 7, wherein the management module is further configured to instruct a third set of the mobile drive units to move respective inventory holders lacking inventory items for the picking tasks from respective initial storage locations to respective subsequent storage locations further from the pick station.

9. An inventory system comprising:

a plurality of inventory holders configured to store inventory items;

a plurality of mobile drive units configured to move the inventory holders;

a plurality of stations, each station comprising at least one station location configured to receive an inventory holder for completion of a task involving at least one inventory item associated with the inventory holder;

a plurality of storage locations, each storage location configured to store an inventory holder when the inventory holder is not at a station location, not being transported en route to a station location, and not being transported en route from a station location; and

a management module configured to;

determine possible movements of the plurality of inventory holders among the plurality of storage locations;

determine a utility of an arrangement of inventory holders in the plurality of storage locations resulting from each of the possible movements; and

instruct at least one of the plurality of drive units to perform at least one of the possible movements based on the determined utility.

10. The inventory system of claim 9, wherein the management module being configured to determine a utility of each of the possible movements comprises the management module being configured to assign a utility score to each of the possible movements, wherein the utility score of each possible movement is based on at least one of:

a drive time involved in the possible movement for a mobile drive unit;

an amount of time a mobile drive unit would deviate from other tasks to perform the possible movement;

an amount of distance a mobile drive unit would deviate from other tasks to perform the possible movement;

a change in distance of an inventory holder relative to a particular station provided by the possible movement;

a degree to which contents of an inventory holder moved by the possible movement match criteria or demands of a particular station;

a timeframe of the demands of a particular station;

future gains in total system efficiency provided by the possible movement;

or

future losses in total system efficiency provided by the possible movement.

11. The inventory system of claim 10, wherein the management module being configured to instruct at least one of the plurality of drive units to perform at least one of the possible movements based on the determined utility comprises the management module being configured to instruct the at least one of the plurality of drive units to perform the at least one of the possible movements having a utility score exceeding a threshold.

12. The inventory system of claim 10, wherein the management module being configured to instruct at least one of the plurality of drive units to perform at least one of the possible movements based on the determined utility comprises the management module being configured to instruct the at least one of the plurality of drive units to perform the at least one of the possible movements having a highest utility score relative to other possible movements.

13. The inventory system of claim 9, wherein the management module being configured to determine possible movements of the plurality of inventory holders among the plurality of storage locations comprises the management module being configured to determine possible movements of the plurality of inventory holders that meet criteria associated with tasks that are predicted to be associated with a particular station.

14. An inventory system comprising:

a plurality of inventory holders configured to store inventory items;

a plurality of mobile drive units configured to move the inventory holders;

a plurality of stations, each station comprising at least one station location configured to receive an inventory holder for completion of a task involving at least one inventory item associated with the inventory holder;

a plurality of storage locations, each storage location configured to receive an inventory holder for storage of the inventory holder when the inventory holder is not at a station location, not being transported en route to a station location, and not being transported en route from a station location; and

a management module configured to;

provide primary instructions to each of a first set of mobile drive units to at least one of move an inventory holder at a station location, move an inventory holder to a station location, or move an inventory holder from a station location; and

provide secondary instructions, to be performed when not performing one of the primary instructions, to each of a second set of mobile drive units to move an inventory holder from one storage location to another storage location.

15. The inventory system of claim 14, wherein the first set of mobile drive units includes at least one of the mobile drive units of the second set of mobile drive units.

16. The inventory system of claim 14, wherein the management module is further configured to provide primary instructions only to the first set of mobile drive units and provide secondary instructions only to the second set of mobile drive units, wherein the first and second sets of mobile drive units are distinct.

17. The inventory system of claim 14, wherein the management module being configured to provide secondary instructions to each of a second set of mobile drive units comprises at least providing instructions to one mobile drive unit to swap the storage locations of at least two inventory holders.

18. The inventory system of claim 14, wherein the management module being configured to provide secondary instructions to each of a second set of mobile drive units comprises at least providing instructions to at least two mobile drive units to swap the storage locations of at least two inventory holders.

19. The inventory system of claim 14, wherein the management module is further configured to provide the secondary instructions so as to facilitate moves predicted to be instructed by the primary instructions.

20. The inventory system of claim 19, wherein the management module is further configured to provide the secondary instructions based on a determined utility of the secondary instructions for facilitating the moves predicted to be instructed by the primary instructions.