Automatic transport loading system and method

• US 7,648,329 B2
• Filed: 05/02/2005
• Issued: 01/19/2010
• 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: Simon, Christopher James, Stevenson, Mark Andrew, Chilson, Gerald Edward, Marino, Mark
• Primary Examiner(s): KEENAN, JAMES W
• Application Number:
  US11/119,588
• Publication Number:
  US 20050244259A1
• Time in Patent Office: 1,723 Days
• Field of Search: 414390-392, 414/399, 414/809, 414/347
• 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 1/0238 using obstacle or wall sensors G05D1/0246 and G05D1/0289 take precedence; lidar systems designed for anti-collision purposes G01S17/93
• 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 is used to travel near the transport and a second guidance system is used to travel on the transport.

Claims

1. A method for loading a transport having a first and second side with an opening defined between the sides, and the transport having a threshold at the opening, with an automatic guided vehicle (AGV) comprising:

engaging a load with said AGV;

guiding said AGV with a first guidance system to a first position and wherein said AGV is at the threshold at said first position;

guiding said AGV with a second guidance system from said first position to an intended load position on said transport, said second guidance system including at least one distance measuring sensor, and wherein at said first position said at least one sensor measures the distance to at least one side of said first and second sides of the transport, the AGV using said measured distance to guide the AGV with said second guidance system from said first position to said intended load position;

depositing said load onto said transport at said intended load position; and

guiding said AGV with said second guidance system from said intended load position to a second position.

2. The method of claim 1 wherein said first guidance system comprises an inertial guidance system.

3. The method of claim 1 wherein said first position is approximately at an end of the transport.

4. The method of claim 1 wherein said second position is similar to said first position.

5. The method of claim 1 wherein the step of guiding said AGV with said second guidance system from said first position to said intended load position on said transport comprises monitoring a drive current of said AGV.

6. The method of claim 5 wherein the step of guiding said AGV with said second guidance system from said first position to said intended load position on said transport further comprises shifting said load to a side of said transport.

7. The method of claim 6 wherein the step of shifting said load to a side of said transport comprises determining when said load has reached said side of said transport.

8. The method of claim 1 wherein said second guidance system guides the AGV at a specified distance from one of the sides of the transport using said distance.

9. The method of claim 8 wherein said second guidance system regularly measures the distance of the AGV to the side of the transport.

10. The method of claim 1 wherein said first guidance system continues to track the location of said AGV while said second guidance system guides said AGV from said first position to said load position.

11. The method of claim 1 wherein said first guidance system continues to track the location of said AGV while said second guidance system continues to guide said AGV from said load position to said second position.

12. A method for loading a transport having a first and second side with an opening defined between the sides, and the transport having a threshold at the opening, with an automatic guided vehicle (AGV) comprising:

engaging a load with said AGV;

guiding said AGV with a first guidance system to a first position at the threshold of the transport, wherein said first guidance system comprises an inertial guidance system;

guiding said AGV with a second guidance system from said first position to an intended load position on said transport, wherein said second guidance system comprises at least one distance measuring device, said at least one distance measuring device determines a first distance to one of the first and second sides of said transport at said first position, whereby said second guidance system uses said first distance to guide said AGV from said first position to said intended load position;

depositing said load onto said transport at said intended load position;

guiding said AGV with said second guidance system from said intended load position to a second position; and

guiding said AGV with said first guidance system from said second position.

13. The method of claim 12 wherein said first guidance system further comprises a track wheel.

14. The method of claim 12 wherein said first guidance system tracks said AGV throughout the steps of guiding said AGV with said second guidance system from said first position to said intended load position, depositing said load onto said transport at said intended load position and guiding said AGV with said second guidance system from said intended load position to said second position.

15. An automatic transport loading system for loading a transport having a first and second side and an opening defined between the sides and the transport having a threshold at the opening, said system comprising:

an automatic guided vehicle (AGV), said AGV comprising a drive mechanism and a steering mechanism; and

a first guidance system and a second guidance system, said first and second guidance systems being operatively coupled with said drive and said steering mechanisms of said AGV, said second guidance system including at least one distance measuring device,

wherein said first guidance system guides said AGV to a first position at the threshold of said transport, wherein said at least one distance measuring device is capable at said first position of measuring a distance to one of the first and second sides at said first position, said second guidance system uses said distance to guide said AGV from said first position to an intended load position and from said intended load position to a second position, and said first guidance system guides said AGV from said second position.

16. The system of claim 15 further comprising a load position sensing device operatively coupled with said drive mechanism and said steering mechanism, said load position sensing device being capable of determining when said AGV is in said intended load position.

17. The system of claim 16 wherein said load position sending device comprises at least one sensor, said sensor being capable of tracking movement of a load engaged with said AGV.

18. The system of claim 15 wherein said second position is approximately at said first position.

19. The system of claim 15 wherein the AGV includes a pair of forks for engaging a load and a drive wheel and a steerable wheel said at least one distance measuring device comprises a pair of sensors, said sensors being capable of detecting a side of said transport and being located between the forks and one of the steerable wheel and the drive wheel.

20. The system of claim 19 wherein said sensor comprises an encoder, said encoder being capable of tracking movement of a load engaged with said AGV.

21. The system of claim 20 wherein said encoder detects said intended load position by determining when said load is impeded from movement.

22. The system of claim 15 wherein said second guidance system includes at least one distance measuring sensor for determining the distance to one side of the transport at said first position.

23. The system of claim 22 wherein said second guidance system guides the AGV at a specified distance from said one side of the transport using said distance.

24. The system of claim 23 wherein said second guidance system regularly measures the distance of the AGV to the side of the transport.

25. The system of claim 15 wherein said first guidance system continues to track the location of said AGV while said second guidance system guides said AGV from said first position to said load position.

26. The system of claim 15 wherein said first guidance system continues to track the location of said AGV while said second guidance system continues to guide said AGV from said load position to said second position.

27. The system of claim 15 wherein said second guidance system includes a sensor being approximately located between said drive wheel and steerable wheel.

28. The system of claim 27 wherein said sensor is a sonic sensor.

29. A method for loading a transport having a first and second side with an opening defined between the sides, and the transport having a threshold at the opening, with an automatic guided vehicle (AGV) comprising:

engaging a load with said AGV;

guiding said AGV with a guidance system having a pair of sensors for measuring distance from a first position to one of the first and second sides and wherein at said first position said AGV is at the threshold of said transport, whereby said guidance system locates an intended load position based on a location of the transport in relation to said first position and wherein as said AGV moves from said first position to the said intended load position, said sensors measure the distance to the sides of the transport;

depositing said load onto said transport at said intended load position; and

guiding said AGV with said pair of sensors from said intended load position to a second position.

30. The method of claim 29 wherein locating said intended load position comprises determining a skew of said transport in relation to an expected transport position.

31. The method of claim 30 wherein the step of determining said skew of said transport comprises measuring a first distance to a first side of said transport, measuring a second distance to a second side of said transport, and comparing said first and second distances, and wherein said step of guiding the AGV includes the step of adjusting the path of the AGV in response to the compared first and second distances.

32. The method of claim 31 wherein said guidance system utilizes said skew to assist with guiding the AGV.

33. A method for unloading a transport having a first and second side with an opening defined between the sides, and the transport having a threshold at the opening, with an automatic guided vehicle (AGV) comprising:

guiding said AGV with a guidance system having a pair of sensors for measuring distance from a first position to one of the first and second sides and wherein at said first position said AGV is at the threshold of said transport, whereby said guidance system locates an approximate load position based on a location of said transport in relation to said first position and as said AGV moves from said first position to said approximate load position, said sensors measure the distance to the sides of the transport;

determining a load position;

engaging a load with said AGV at said load position; and

guiding said AGV with said pair of sensors from said load position to a second position.

34. The method of claim 33 wherein locating said approximate load position comprises determining a skew of said transport in relation to an expected transport position.

35. The method of claim 34 wherein the step of determining said skew of said transport comprises measuring a first distance to a first side of said transport, measuring a second distance to a second side of said transport, and comparing said first and second distances, and wherein said step of guiding the AGV includes the step of adjusting the path of the AGV in response to the compared first and second distances.

36. The method of claim 35 wherein said guidance system utilizes said skew to assist with guiding the AGV.

37. A method for unloading a transport having a first and second side with an opening defined between the sides, and the transport having a threshold at the opening, with an automatic guided vehicle (AGV) comprising:

guiding said AGV with a first guidance system to a first position at the threshold of the transport;

guiding said AGV with a second guidance system from said first position to an expected load position on said transport and wherein said second guidance system includes sensors capable of measuring the distance to one of the first and second side at said first position and as said AGV moves to said expected load position;

determining a load position;

engaging a load with said AGV at said load position; and

guiding said AGV with said second guidance system from said load position to a second position.

38. The method of claim 37 wherein said first guidance system comprises an inertial guidance system.

39. The method of claim 37 wherein said first position is approximately at an end of the transport.

40. The method of claim 37 wherein said second position is similar to said first position.

41. The method of claim 37 wherein the step of determining a load position comprises monitoring a drive current of said AGV.

42. The method of claim 37 wherein the step of determining a load position comprises utilizing at least one optical sensor to detect a load pocket.