Automatic transport loading system and method

• US 8,192,137 B2
• Filed: 06/21/2007
• Issued: 06/05/2012
• 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: Ross, Wayne David, Chilson, Gerald Edward
• Primary Examiner(s): KEENAN, JAMES W
• Application Number:
  US11/766,646
• Publication Number:
  US 20070269299A1
• Time in Patent Office: 1,811 Days
• Field of Search: 414390-392, 414/399, 414/809, 701/26, 701/221
• 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: 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 first 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 sidewall and an adjacent end wall, with an automatic guided vehicle (AGV) comprising:

engaging a 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;

creating, at approximately said position A, a data profile of the transport, by sensing at least more than one location of the sidewall of the transport and the adjacent end wall of the transport;

determining a transport path for depositing the load at an intended load position on the transport using the data profile from said step of creating a data profile;

guiding the AGV along the determined transport path and into the transport 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 further including a step of guiding the AGV along the determined transport path from the intended load position to position A after said step of depositing the load.

3. The method of claim 2 further including the step 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.

4. The method of claim 1 wherein in said step of creating a data profile, said sensing said sidewall is performed by a laser sensor.

5. The method of claim 1 wherein said step of sensing said sidewall is performed by a sensor remote from the AGV.

6. The method of claim 1 wherein in said step of creating a data profile, said sensing said sidewall and an adjacent end wall is performed by a sensor located on the AGV.

7. The method of claim 6 further including the step of providing information from said sensor regarding said sidewall of the transport to a central controller and wherein the central controller performs said step of determining said transport path.

8. The method of claim 7 further including the step of communicating the determined transport path to the guidance system on the AGV.

9. The method of claim 1 wherein the guidance system comprises an inertial guidance system.

10. The method of claim 1 wherein said step of depositing said load further includes the steps of:

lowering said load before reaching said load position;

pushing said load along the floor of the transport to said intended load position;

measuring a pressure required to push said load to said intended load position; and

stopping the pushing of said load when said measured pressure exceeds a set value.

11. The method of claim 10 wherein said step of measuring said pressure is performed by monitoring the current supplied to a motor on the AGV.

12. The method of claim 1 wherein said step of creating a data profile further includes the step of determining a skew and an offset of the transport.

13. The method of claim 1 further including the step of calibrating an actual position of the AGV after said step of guiding the AGV to a position A, and before said step of guiding the AGV along the determined optimal transport path.

14. The method of claim 13 wherein said step of calibration further includes the step of gathering data of a fixed object in proximity to the transport and comparing said actual location of the AGV relative to said fixed object to an expected location of the AGV relative to said fixed object.

15. The method of claim 14 further including said step of updating the guidance system with said actual location of the AGV.

16. The method of claim 1 further including the steps of unloading the transport before said step of engaging a load with the AGV and wherein said steps of unloading comprise:

directing an AGV to said position A;

creating a first data profile, at approximately said position A of the transport and loads, by sensing at least more than one location of the sidewall of the transport and the adjacent end wall and at least the first load;

determining an unloading transport path using the data profile created in said step of creating a data profile;

directing the AGV along the determined unloading transport path to the first load;

engaging the first load;

directing the AGV along the determined unloading transport path to position A;

updating the AGV with a system travel path;

switching to the system travel path when the AGV reaches approximately position A; and

directing the AGV along the system travel path.

17. The method of claim 16 further including the steps of:

directing an AGV to said position A;

sensing at least more than one location of the sidewall of the transport, along with the adjacent end wall, and an approximate location of a next load within the transport with a sensor to create a subsequent data profile;

determining an updated transport path with a controller located on the AGV by averaging the information received from said sensor each time the step of sensing the sidewall is performed to create a subsequent data profile;

directing the AGV along the updated transport path to said next load;

engaging said next load;

directing the AGV along said updated transport path to position A;

updating the AGV with a system travel path;

switching to said system travel path when the AGV reaches position A; and

directing the AGV along said system travel path.

18. The method of claim 16 further including a central controller and wherein said AGV provides said location of said sidewall to said central controller and said central controller provides said transport path to a different AGV.

19. The method of claim 1 further including both a sensor on the AGV and a sensor external from the AGV.

20. The method of claim 1 further including the step of providing the determined transport path to at least one additional AGV.

21. The method of claim 1 further including the step of updating the transport path at position A to create an updated transport path from position A to intended load position for the load engaged by the AGV.

22. The method of claim 1 further including the step of removing the determined transport path from the AGV.

23. The method of claim 21 further including the step of providing the updated transport path to a subsequent AGV.

24. A method for loading a transport, having at least one sidewall and an end wall, adjacent to the sidewall with an automatic guided vehicle (AGV) comprising:

engaging a load with the AGV;

guiding the AGV with an inertial guidance system to a position A;

creating, at approximately said position A, a data profile of the transport by sensing at least more than one location of the sidewall of the transport and the adjacent end wall of the transport;

determining a transport path from position A to an intended load position on the transport using the data profile from said step of creating a data profile;

aligning the AGV with the determined transport path;

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

depositing the load; and

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

25. The method of claim 24 further including the step of calibrating a location of the AGV during said step of determining a transport path.