System and method for generating a path for a mobile drive unit

• US 8,538,692 B2
• Filed: 06/19/2006
• Issued: 09/17/2013
• Est. Priority Date: 06/19/2006
• Status: Active Grant

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Inventors: Wurman, Peter R., D'Andrea, Raffaello, Barbehenn, Michael T., Hoffman, Andrew E., Mountz, Michael C.
• Primary Examiner(s): Tran, Khoi
• Assistant Examiner(s): FIGUEROA, JAIME
• Application Number:
  US11/425,057
• Publication Number:
  US 20080051984A1
• Time in Patent Office: 2,647 Days
• Field of Search: 700/200, 700/214, 700/217, 700/228, 701/201, 340/988
• US Class Current: 701/532
• CPC Class Codes: G05D 1/0297 by controlling means in a control room
• CPC Class Codes: G05D 2201/0216 Vehicle for transporting goods in a warehouse, factory or similar
• CPC Class Codes: G05D 3/00 Control of position or direction G05D1/00 takes precedence; numerical control to execute positioning G05B19/18
• 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: G06Q 50/40 Business processes related to the transportation industry shipping G06Q10/083

Abstract

A method of transporting inventory items includes receiving a route request from a mobile drive unit. The route request identifies a destination location within a workspace. The workspace includes at least one cell associated with a first cell attribute and at least one cell that is not associated with the first cell attribute. The method includes determining a state of the mobile drive unit. The method also includes generating a path to the destination location for the mobile drive unit that traverses cells associated with the first cell attribute, in response to determining that the mobile drive unit is associated with a first state. The method includes generating a path to the destination location for the mobile drive unit that does not traverse cells associated with the first cell attribute, in response to determining the mobile drive unit is not associated with the first state. The method further includes transmitting the path to the mobile drive unit.

Claims

1. A method of transporting inventory items, comprising:

receiving a route request from a mobile drive unit, the route request identifying a destination location within a workspace, wherein the workspace comprises at least one cell associated with a first cell attribute and at least one cell that is not associated with the first cell attribute;

determining a state of the mobile drive unit;

in response to determining that the mobile drive unit is associated with a first state, generating a path to the destination location for the mobile drive unit that traverses cells associated with the first cell attribute;

in response to determining the mobile drive unit is not associated with the first state, generating a path to the destination location for the mobile drive unit that does not traverse cells associated with the first cell attribute; and

transmitting the path to the mobile drive unit.

2. The method of claim 1, wherein determining the state of the mobile drive unit comprises determining whether the mobile drive unit is currently docked with another component.

3. The method of claim 1, wherein determining the state of the mobile drive unit comprises determining whether the mobile drive unit is currently bearing a load.

4. The method of claim 1, wherein determining the state of the mobile drive unit comprises determining whether the mobile drive unit is currently assigned a task to be completed.

5. The method of claim 1, wherein the first cell attribute is associated with cells that require tunneling.

6. The method of claim 1, wherein the first cell attribute is associated with cells in which inventory holders are stored when not being transported.

7. The method of claim 1, wherein the first cell attribute is associated with cells having a height restriction for devices that move through the associated cells.

8. The method of claim 1, wherein the first cell attribute is associated with cells having a width restriction for devices that move through the associated cells.

9. The method of claim 1, wherein determining the state of the mobile drive unit comprises:

prior to receiving the route request, receiving information from the mobile drive unit identifying a state of the mobile drive unit;

storing the received information;

identifying the state of the mobile drive unit based on the stored information.

10. The method of claim 1, wherein receiving the route request comprises receiving a route request that identifies the destination location and that includes information indicating a state of the mobile drive unit;

and

wherein determining the state of the mobile drive unit comprises identifying the state of the mobile drive unit based, at least in part, on the information included in the route request.

11. A system for transporting inventory items, comprising:

a mobile drive unit;

a plurality of inventory holders;

a workspace comprising a plurality of workspace cells, wherein at least one cell is associated with a first cell attribute and at least one cell is not associated with the first cell attribute; and

a management module operable to;

receive a route request from a mobile drive unit, the route request identifying a destination location within the workspace;

determine a state of the mobile drive unit;

in response to determining the mobile drive unit is associated with a first state, generate a path to the destination location for the mobile drive unit that traverses cells associated with the first cell attribute;

in response to determining the mobile drive unit is not associated with the first state, generate a path to the destination location for the mobile drive unit that does not traverse cells associated with the first cell attribute; and

transmit the path to the mobile drive unit.

12. The system of claim 11, wherein the management module is operable to determine the state of the mobile drive unit by determining whether the mobile drive unit is currently docked with another component.

13. The system of claim 11, wherein the management module is operable to determine the state of the mobile drive unit by determining whether the mobile drive unit is currently bearing a load.

14. The system of claim 11, wherein the management module is operable to determine the state of the mobile drive unit by determining whether the mobile drive unit is currently assigned a task to be completed.

15. The system of claim 11, wherein the first cell attribute is associated with cells in which inventory holders are stored when not being transported.

16. The system of claim 11, wherein the first cell attribute is associated with cells that require tunneling.

17. The system of claim 11, wherein the first cell attribute is associated with cells having a height restriction.

18. The system of claim 11, wherein the first cell attribute is associated with cells having a width restriction.

19. The system of claim 11, wherein the management module is operable to determine the state of the mobile drive unit by:

prior to receiving the route request, receiving information from the mobile drive unit identifying a state of the mobile drive unit;

storing the received information; and

identifying the state of the mobile drive unit based on the stored information.

20. The system of claim 11, wherein the management module is operable to:

receive the route request by receiving a route request that identifies the destination location and that includes information indicating a state of the mobile drive unit; and

determine the state of the mobile drive unit by identifying the state of the mobile drive unit based, at least in part, on the information included in the route request.

21. A management module for managing mobile drive units, the management module operable to:

receive a route request from a mobile drive unit, the route request identifying a destination location within the workspace;

determine a state of the mobile drive unit;

in response to determining the mobile drive unit is associated with a first state, generate a path to the destination location for the mobile drive unit that traverses cells associated with the first cell attribute;

in response to determining the mobile drive unit is not associated with the first state, generate a path to the destination location for the mobile drive unit that does not traverse cells associated with the first cell attribute; and

transmit the path to the mobile drive unit.

22. A system for transporting inventory items, comprising:

means for receiving a route request from a mobile drive unit, the route request identifying a destination location within a workspace, wherein the workspace comprises at least one cell associated with a first cell attribute and at least one cell that is not associated with the first cell attribute;

means for determining a state of the mobile drive unit;

means for generating a path to the destination location for the mobile drive unit that traverses cells associated with the first cell attribute, in response to determining that the mobile drive unit is associated with a first state;

means for generating a path to the destination location for the mobile drive unit that does not traverse cells associated with the first cell attribute, in response to determining the mobile drive unit is not associated with the first state; and

means for transmitting the path to the mobile drive unit.