Material handling system using autonomous mobile drive units and movable inventory trays

• US 6,895,301 B2
• Filed: 02/03/2003
• Issued: 05/17/2005
• Est. Priority Date: 07/15/2002
• Status: Expired due to Term

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Distrobot Systems, Inc. (Amazon.com, Inc.)
• Inventors: Mountz, Michael C.
• Primary Examiner(s): Tran, Khoi H.
• Application Number:
  US10/357,853
• Publication Number:
  US 20040093116A1
• Time in Patent Office: 834 Days
• Field of Search: 700/215, 700/213, 700/214, 700/216, 700/217, 700/225, 700/226, 700/228, 700/113, 700/115, 700/245, 701/1, 701/2, 701/23, 701/300, 701/301, 701/213
• US Class Current: 700/215
• CPC Class Codes: G05D 1/0227 using mechanical sensing means, e.g. for sensing treated area
• CPC Class Codes: G05D 1/0236 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/024 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0242 using non-visible light signals, e.g. IR or UV signals
• CPC Class Codes: G05D 1/0255 using acoustic signals, e.g. ultra-sonic singals sonar systems designed for anti-collision purposes G01S15/93
• CPC Class Codes: G05D 1/0257 using a radar radar systems designed for anti-collision purposes between land vehicles or between land vehicle and fixed obstacles G01S13/931
• CPC Class Codes: G05D 1/0259 using magnetic or electromagnetic means
• CPC Class Codes: G05D 1/027 comprising intertial navigation means, e.g. azimuth detector inertial navigation G01C21/16; inertial navigation combined with non-inertial navigation instruments G01C21/165
• CPC Class Codes: G05D 1/0274 using mapping information stored in a memory device navigation using map-matching G01C21/30
• CPC Class Codes: G05D 1/0278 using satellite positioning signals, e.g. GPS
• CPC Class Codes: G05D 1/0297 by controlling means in a control room

Abstract

An inventory system includes a plurality of mobile drive units with a processor control and with a positioning system that enables the mobile drive units to navigate a factory floor. The mobile drive units interface with a material handling system to receive order requests and deliver inventory items to pack stations located on the factory floor. The inventory items are stored in trays stacked into movable inventory pods, which may be transported by the mobile drive units throughout the factory floor. The mobile drive units dock and undock with the movable inventory pods using a docking mechanism. The movable inventory pods are stored in a virtual storage grid when they are not being transported by the mobile drive units. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

Claims

1. A system for inventory management in a warehouse, comprising:

one or more mobile drive units (MDUs), each MDU having a communication link coupled to a processor, a docking mechanism, and a power unit coupled to a drive mechanism configured to move the MDU about the warehouse responsive to control signals of the processor, the MDU receiving command signals via the communication link; and

a plurality of movable inventory pods (MIPs), each MIP containing inventory items and being configured for attachment to the docking mechanism of the MDU, the MDU docking with a MIP to transport the MIP across the warehouse responsive to the command signals.

2. The system of claim 1 further comprising:

a material handling system (MHS); and

one or more pack stations, each pack station being configured to transmit the command signals to the MDUs responsive to an order request issued by the MHS.

3. The system of claim 1 wherein the control signals are generated by the processor responsive to command signals received via the communication link.

4. The system of claim 2 wherein the order request is transmitted from the MHS to a computer located at a pack station.

5. The system of claim 1 further comprising:

one or more pack stations;

a material handling system (MHS) that transmits the command signals to the MDUs, and

wherein the MIP is delivered to a particular pack station responsive to the command signals.

6. The system of claim 2 wherein the processor of the one or more MDUs performs calculations upon receipt of the order request to determine a time duration for transporting a particular movable inventory pod to a particular pack station.

7. The system of claim 6 wherein each MDU transmits a bid for the order request to a computer located at the pack station via the wireless network using an RF system coupled to the communications link of the one or more MDUs.

8. The system of claim 7 wherein the computer at the pack station selects a MDU that calculates that it could fulfill the order request in the least amount of time.

9. The system of claim 1 wherein each of the MDUs contains a guidance system that provides position signals to the processor.

10. The system of claim 9 wherein the guidance system comprises a pseudolite indoor global positioning system (GPS).

11. The system of claim 10 wherein the one or more MDUs navigate the factory floor using information provided by the GPS.

12. The system of claim 11 wherein the one or more MDUs generate a map of the position coordinates of the plurality of MIPs located in the warehouse.

13. The system of claim 2 wherein a plurality of order requests is processed simultaneously through the one or more pack stations.

14. The system of claim 2 wherein a plurality of order requests is processed in real-time.

15. The system of claim 1 wherein one or more MIPs are configured as vertically stackable trays.

16. The system of claim 15 wherein one or more of the stackable trays comprises a plurality of bins.

17. The system of claim 1 wherein the plurality of movable inventory pods are stored in a virtual grid on a factory floor.

18. A system for inventory management in a warehouse, comprising:

one or more mobile drive units (MDUs), each MDU having a communication link coupled to a processor, a docking mechanism, and a power unit coupled to a drive mechanism configured to move the MDU about the warehouse responsive to control signals of the processor, the MDU receiving command signals via the communication link;

a plurality of movable inventory pods (MIPs), each MIP containing inventory items and being configured for attachment to the docking mechanism of the MDU, the MDU docking with a MIP to transport the MIP across the warehouse responsive to the command signals;

a material handling system (MHS); and

one or more pack stations, each pack station being configured to transmit the command signals to the MDUs responsive to an order request issued by the MHS.

19. The system of claim 18 wherein the control signals are generated by the processor responsive to command signals received via the communication link.

20. The system of claim 18 wherein the order request is transmitted from the MHS to a computer located at a pack station.

21. The system of claim 18 wherein the MIP is delivered to a particular pack station responsive to the command signals.

22. The system of claim 21 wherein the processor of the one or more MDUs performs calculations upon receipt of the order request to determine a time duration for transporting a particular movable inventory pod to a particular pack station.

23. The system of claim 22 wherein each MDU transmits a bid for the order request to a computer located at the pack station via the wireless network using an RF system coupled to the communications link of the one or more MDUs.

24. The system of claim 23 wherein the pack station computer selects a MDU that calculates that it could fulfill the order request in the least amount of time.

25. The system of claim 18 wherein the one or more MDUs generate a map of the position coordinates of the plurality of MIPs in the warehouse.

26. The system of claim 18 wherein each of the MDUs comprises means for communicating information with the MHS and peer MDUs using a wireless network.

27. The system of claim 26 wherein the means comprise infrared technology (IR).

28. The system of claim 26 wherein the information includes coordinate information for each of the MDUs and inventory item information stored in particular MIP.

29. The system of claim 28 further comprising means for transmitting the information to the MHS.

30. The system of claim 18 wherein the plurality of MIPs are stored in a virtual grid on a factory floor.

31. The system of claim 18 wherein each of the MDUs contains a global positioning system (GPS), each MDU navigating the warehouse autonomously using information provided by the GPS.

32. The system of claim 18 wherein a radio frequency identification (RFID) is embedded in each of the MIPs to identify each MIP located on a factory floor.

33. The system of claim 32 wherein the RFID also identifies items of inventory contained within each MIP.

34. The system of claim 18 wherein the command signals are transmitted from the MHS to one or more check-in stations coupled to the MHS, the command signals indicating that particular items of inventory need replenishment.

35. The system of claim 34 wherein a check-in station computer selects a MDU to transport an MIP containing at least one empty bin to a check-in station to replenish items of inventory.

36. The system of claim 18 wherein the one or more MDUs docked to MIPs containing at least one empty bin form queue lanes along the sides of a factory floor to await inventory replenishment requests from one or more check-in station computers.

37. The system of claim 36 wherein the one or more MDU'"'"'s transport the MIPs to a check-in station to receive items of inventory.

38. The system of claim 18 wherein the command signals are transmitted to the MDUs via a wireless network.

39. A system for inventory management comprising:

a plurality of mobile drive units (MDUs) with docking mechanisms;

a plurality of movable inventory pods (MIPs) with docking mechanisms for attachment to the MDU'"'"'s docking mechanisms;

one or more pack stations;

a material handling system (MHS); and

a wireless network.

40. The system of claim 39 wherein the one or more pack stations are configured to respond to an order request from the MHS.

41. The system of claim 39 wherein each of the MDUs have a communications link coupled to a processor, each of the MDUs also having a power unit coupled to a drive mechanism configured to move the MDU about the warehouse responsive to control signals of the processor.

42. The system of claim 41 wherein the control signals are generated responsive to command signals received by the communications link.

43. The system of claim 39 wherein each of the MDUs are configured to dock with a movable inventory pod to transport the movable inventory pod across a warehouse.

44. The system of claim 39 wherein an order request is transmitted from the MHS to a computer located at a pack station.

45. The system of claim 44 wherein the computer located at the pack station transmits the order request for items of inventory using an RF transmitter through the wireless network to the communications link of the one or more MDUs.

46. The system of claim 45 wherein the processor of the one or more MDUs performs calculations upon receipt of the order request to determine a time duration for transporting a particular MIP to a particular pack station.

47. The system of claim 46 wherein each MDU transmits a bid for the order request to the computer located at the pack station via the wireless network using an RF system coupled to the communications link of the one or more MDUs.

48. The system of claim 47 wherein the computer at the pack station selects a MDU that calculates that it could fulfill the order request in the least amount of time.

49. The system of claim 41 wherein each of the MDUs contains a global positioning system (GPS) that provides position signals to the processor.

50. The system of claim 49 wherein the plurality of MDUs navigate the factory floor using information provided by the GPS.

51. The system of claim 50 wherein the one or more MDUs generate a map of the position coordinates of the plurality of movable inventory pods on the factory floor.

52. The system of claim 39 wherein one or more order requests is processed through the one or more pack stations.

53. The system of claim 39 wherein one or more of the MIPs are configured as vertically stackable trays.

54. The system of claim 39 wherein the plurality of MIPs are stored in a virtual grid on a factory floor.

55. The system of claim 39 further comprising a plurality of check-in stations, a computer at a check-in station notifying the plurality of MDUs via the wireless network when an empty pod is needed for a replenishment activity.

56. The system of claim 55 wherein a check-in station computer selects a MDU to transport an empty movable inventory pod to a check-in station to replenish items of inventory.

57. The system of claim 39 wherein a radio frequency identification (RFID) is embedded in each of the MIPs to identify each MIP located on a factory floor.

58. The system of claim 57 wherein the RFID also identifies items of inventory contained within each MIP.

59. The system of claim 39 wherein each of the MDUs comprises means for communicating information with peer MDUs using the wireless network, the information including coordinate information for each of the MDUs and inventory item information stored in particular movable inventory pods.

60. The system of claim 39 wherein each of the MDUs comprises means for transmitting information to the MHS, the information including coordinate information for each of the MDUs and inventory item information stored in particular movable inventory pods.

61. The system of claim 60 wherein the MHS transmits the information received from each of the MDUs to the plurality of the MDUs using the wireless network.

62. A system for inventory management in a warehouse, comprising:

one or more mobile drive units (MDUs), each MDU having a communication link coupled to a processor, a docking mechanism, and a power unit coupled to a drive mechanism configured to move the MDU about the warehouse responsive to control signals of the processor, each MDU receiving command signals via the communication link;

a plurality of movable inventory pods (MIPs), each MIP for holding inventory items and being configured for attachment to the docking mechanism of the MDU responsive to the command signals;

a computer to transmit an order request for an item of inventory to a particular MDU.

63. The system of claim 62 wherein the computer tracks position coordinates of the one or more MDUs located on a factory floor by communicating via a wireless network.

64. The system of claim 62 wherein the control signals are generated by the processor responsive to the command signals received via the communication link.

65. The system of claim 62 wherein the computer selects the particular MDU to fulfill the order request based on an algorithm.

66. The system of claim 62 wherein the order request is transmitted to the particular MDU via a wireless network.

67. The system of claim 62 further comprising a radio frequency identification (RFID) chip attached to each of the MIPs.