AUTOMATIC TRANSPORT LOADING SYSTEM AND METHOD

• US 20080199298A1
• Filed: 04/28/2008
• Published: 08/21/2008
• Est. Priority Date: 05/03/2004
• Status: Active Grant

• Current Assignee: Jervis B Webb Company (Daifuku Company Limited)
• Original Assignee: Jervis B Webb Company (Daifuku Company Limited)
• Inventors: Chilson, Gerald Edward, Ross, Wayne David
• Granted Patent: US 7,980,808 B2
• Time in Patent Office: Days
• US Class Current: 414/809
• CPC Class Codes: B60L 15/2036 Electric differentials, e.g. for supporting steering vehicles
• CPC Class Codes: B60L 15/38 with automatic control
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 2200/42 Fork lift trucks
• CPC Class Codes: B60L 2260/32 Auto pilot mode
• CPC Class Codes: B66F 9/063 Automatically guided
• CPC Class Codes: B66F 9/0755 Position control; Position detectors
• CPC Class Codes: B66F 9/085 Multiple forks, i.e. more than one pair mounted on a single mast or with more than one mast
• CPC Class Codes: G05D 1/024 in combination with a laser lasers per se H01S
• 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 1/0272 comprising means for registering the travel distance, e.g. revolutions of wheels measuring distance traversed on the ground by vehicles, e.g. using odometers G01C22/00
• CPC Class Codes: Y02P 90/60 Electric or hybrid propulsion means for production processes
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

A method and system for automatically loading and unloading a transport is disclosed. A guidance system follows a travel path to a position near the transport and then a sensor profiles a transport so that a transport path is determined for an AGV to follow into the transport to place a load and for exiting the transport upon placement of the load.

Claims

1. A method for loading a transport having a threshold and at least one of a floor and a roof with an automatic guided vehicle (AGV) having a pair of forks for lifting a load, said method comprising:

engaging the load with the AGV;

guiding the AGV with a guidance system to a position A and wherein the position A is located outside of the transport;

determining a transport path for depositing the load at an intended load position on the transport;

determining the location of one of the transport floor and the transport roof;

guiding the AGV along the determined transport path with the guidance system to the intended load position; and

depositing the load onto the transport at the intended load position.

2. The method of claim 1 wherein said step of determining the location of one of the transport floor and the transport roof determines the location of the transport floor and the transport roof relative to the supporting surface of the AGV.

3. The method of claim 2 wherein the supporting surface of the AGV is substantially located outside the threshold.

4. The method of claim 3 wherein the supporting surface of the AGV is proximate to the threshold.

5. The method of claim 1 further including the step of determining that the load to be deposited has an intended load position within a set distance of the threshold of the transport, before said step of guiding the AGV along the determined transport path.

6. The method of claim 5 wherein said step of guiding the AGV along the determined transport path further includes the step of determining when the load enters the threshold of the transport.

7. The method of claim 6 wherein said step of guiding the AGV along the determined transport path further includes the step of moving the forks in a coordinated motion with the movement of the AGV along the longitudinal axis of the transport, after performing said step of determining when the load enters the threshold of the transport.

8. The method of claim 7 wherein said step of moving the forks in a coordinated motion further includes the step of determining the angle of the transport floor relative to the angle of the support surface of the AGV.

9. The method of claim 8 wherein said support surface is at least one of the floor of the loading bay area or a dock ramp.

10. The method of claim 7 wherein said step of moving the forks in a coordinated motion further includes the step of moving at least one of an elevator mechanism or a fork carriage on the AGV.

11. The method of claim 7 wherein said step of moving at least one of an elevator mechanism or a fork carriage is performed by pivoting said at least one of an elevator mechanism or a fork carriage.

12. The method of claim 1 further including the steps of switching from the determined transport path to a system path at position A, after said step of guiding the AGV along the determined transport path from the intended load position to position A, and tilting the load in response to said step of determining the location of one of the transport floor and the transport roof.

13. The method of claim 10 further including the step of determining the relative angle of one of the transport floor and transport roof to the AGV before the AGV passes the threshold of the transport.

14. The method of claim 13 wherein said AGV determines the angle of its supporting surface from level to determine the relative angle of the transport floor from the supporting surface of the AGV.

15. The method of claim 1 further including the step of determining if the load or forks on the AGV will contact the transport floor as the AGV is guided to the intended load position.

16. The method of claim 15 further including the step of tilting the load in response to determining that one of the load or forks on the AGV will contact the transport floor as the AGV is guided to the intended load position.

17. The method of claim 16 wherein said step of depositing said load occurs after said step of tilting the load.

18. The method of claim 16 wherein said step of depositing said load occurs while said load is tilted in response to determining that the load or forks will contact the transport floor as the AGV is guided to the intended load position.

19. The method of claim 17 wherein one of an elevator mechanism and fork carriage is tilted to perform said step of tilting the load and said method further includes the step of at least partially removing the forks while one of the elevator mechanisms and fork carriage is tilted.

20. The method of claim 19 wherein said one of an elevator mechanism and fork carriage is returned to a normal position from a tilted position as said AGV travels to obtain the next load.

21. The method of claim 1 wherein said step of determining the location of one of the transport floor and transport roof is performed by a sensor selected from the group consisting essentially of vision sensors, camera sensors, lasers, LADAR sensors, radar sensors, optic sensors, and sonic sensors.

22. The method of claim 21 wherein said sensor is remotely located from the AGV.

23. The method of claim 21 wherein said sensor is located on the AGV.

24. The method of claim 1 wherein the step of guiding the AGV to position A further includes the step of rotating the AGV 180 degrees before reaching position A.

25. The method of claim 1 wherein said step determining a transport path also includes the step of sensing the threshold of the transport, including the location of the threshold relative to the walls of the loading facility.

26. The method of claim 1 further including the step of calibrating the actual position of the AGV after said step of guiding the AGV to a position A.

27. The method of claim 26 wherein said step of calibration further includes the step of gathering data of a fixed object in proximity to the transport and comparing the location actual location of the AGV relative to the fixed object to the expected location of the AGV relative to the fixed object.

28. The method of claim 27 further including the step of updating the guidance system with the actual location of the AGV in the system.

29. The method of claim 1 further including the step of allowing the forks to float substantially freely in an approximately vertical direction during said step of depositing the load.

30. The method of claim 1 wherein the AGV further includes a fork carriage and an elevator mechanism having a longitudinal axis for lifting the load along the longitudinal axis and wherein at least one of the fork carriage and forks may move freely approximately in line with the longitudinal axis.

31. A method for loading a transport with an automatic guided vehicle (AGV) comprising:

engaging a load with the AGV;

guiding the AGV with one of a laser, inertial guidance system, optic guidance system, or magnetic guidance system to a position A;

determining a transport path from position A to an intended load position on the transport;

determining the location of one of the transport floor and the transport roof;

aligning the AGV with the determined transport path;

guiding the AGV along the determined transport path using the inertial guidance system from position A to the intended load position;

depositing the load; and

guiding the AGV along the transport path using the guidance system from the intended load position to position A.

32. The AGV of claim 31 wherein said step of depositing the load further includes the step of coordinating the pivoting of the forks with the motion of the AGV along the transport path.

33. The AGV of claim 32 wherein said step of coordinating the pivoting of the forks further includes the step of angling the forks to approximately parallel the transport floor.

34. The AGV of claim 31 wherein said step of determining a transport path further includes a step of determining a fork pivoting motion related to the position of the AGV within the transport.

35. The AGV of claim 34 wherein said step of guiding said AGV from said deposited load includes at least one adjustment of the angle of forks relative to the transport floor.

36. The AGV of claim 31 wherein said step of guiding the AGV from said deposited load further includes the step of adjusting the forks at least angularly to minimize engagement with a pallet supporting the load.

37. The AGV of claim 36 further including the step of adjusting the forks vertically as said forks are adjusted at least angularly.

38. A method for loading a transport with automatic guided vehicles (AGVs) using an AGV system having a central controller and an AGV controller on each AGV, said method comprising:

directing the AGV to engage a load and travel along a system travel path to a position A, wherein position A is located near a loading bay door;

sensing the location of sidewalls of the transport and at least one of a roof and floor of the transport located at a loading bay door near position A;

determining a transport path for the AGV to follow into the transport;

determining tilting load adjustments for the AGV to follow near the threshold of the transport;

adding the transport path and tilting load adjustments to the system travel paths in the central controller;

guiding the AGV along the transport path to a determined load position; and

depositing the load.

39. The method of claim 38 further including the step of coordinating with the motion of the AGV along the transport path the motion of forks holding the load to compensate for any determined load adjustments.