System and method for guiding automated guided vehicle

• US 9,207,676 B2
• Filed: 11/27/2012
• Issued: 12/08/2015
• Est. Priority Date: 12/15/2011
• Status: Active Grant

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Wu, Cheng-Hua, Ho, Yu-Lun, Pu, Yueh-Ju, Kuo, Ching-Yi, Hu, Jwu-Sheng
• Primary Examiner(s): To, Tuan C.
• Assistant Examiner(s): FOUCHE, MICHAEL P
• Application Number:
  US13/686,626
• Publication Number:
  US 20130158773A1
• Time in Patent Office: 1,106 Days
• Field of Search: 701/23, 701/25, 701/24, 318/587
• US Class Current: 1/1
• CPC Class Codes: G05D 1/0231 using optical position detecting means position-fixing by using electromagnetic waves other than radio waves, e.g. optical position detecting means G01S5/16
• CPC Class Codes: G05D 1/0236 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0246 using a video camera in combination with image processing means
• CPC Class Codes: G05D 1/0261 using magnetic plots

Abstract

A system for guiding an automated guided vehicle (AGV) is provided. The system includes a guidance path, an AGV, an image capturing apparatus and an operation unit. The guidance path guides the AGV. The AGV moves on the guidance path and is guided by the guidance path. The AGV moves in a vision guidance region after departing from the guidance path. The image capturing apparatus captures a vision guidance region associated image. The vision guidance region associated image at least includes an image of the vision guidance region. The operation unit determines whether the AGV departs from the guidance path, and calculates position information of the AGV in the vision guidance region. When the AGV departs from the guidance path, the operation unit guides the AGV according to the vision guidance region associated image.

Claims

1. A system for guiding an automated guided vehicle (AGV), comprising:

a guidance path, for guiding the AGV;

wherein the AGV moves on the guidance path when the AGV is on the guidance path;

an image capturing apparatus, for capturing a vision guidance region associated image at least comprising an image of the vision guidance region; and

an operation unit, for determining whether the AGV is departed from the guidance path, and guiding the AGV according to the vision guidance region associated image when the AGV is departed from the guidance path;

wherein the guidance path comprises a first branch and a second branch, the first branch comprises a first terminal, and the second branch comprises a second terminal, and the vision guidance region is a non-guidance-path region between the first terminal and the second terminal;

when the AGV departs from the first terminal of the guidance path and enters the vision guidance region, the AGV is guided by the operation unit rather than the guidance path until the AGV arrives at the second terminal, the operation unit guides the AGV according to the vision guidance region associated image when the AGV enters the vision guidance region.

2. The system according to claim 1, further comprising:

a first tag used to identify signal, disposed at the first terminal;

a second tag used to identify signal, disposed at the second terminal;

an tag reader, disposed at the AGV, for reading the first tag or the second tag as a trigger for a mechanism of the operation unit for guiding the AGV.

3. The system according to claim 1, further comprising:

a wireless communication module, disposed at the AGV, for informing the operation unit to determine whether the AGV is departed from the guidance path when the AGV reads the first tag or the second tag.

4. The system according to claim 1, wherein the vision guidance region associated image is the image of the vision guidance region, and operation unit determines that the AGV is departed from the guidance path when the vision guidance region associated image displays the AGV.

5. The system according to claim 1, wherein the operation unit visually calculates relative position information of the AGV and the second terminal according to the vision guidance region associated image, visually calculates included angle information between the AGV and the second branch according to the vision guidance region associated image, and performs route planning according to the relative information and the included angle information.

6. The system according to claim 1, wherein the operation unit performs route planning for a shortest path in the vision guidance region for the AGV according to a minimum cut angle of the second branch.

7. The system according to claim 1, wherein the operation unit calculates an intersection of extension directions of the first branch and the second branch, a connecting line between the first terminal and the intersection is defined as a first segment and a connecting line between the second terminal and the intersection is defined as a second segment;

the operation unit selects a shorter segment of the first and second segments and utilizes a physical terminal of the shorter segment as a passing point;

the operation unit finds a circle that is tangent to extension directions of the first branch and the second branch according to the passing point, with the circle being tangent to the extension direction of the second branch at a tangent point;

the operation unit performs route planning for the AGV in the vision guidance region according to the first terminal, the tangent point, the second terminal and the circle.

8. The system according to claim 1, wherein the operation unit calculates an intersection of extension directions of the first branch and the second branch, a connecting line between the first terminal and the intersection is defined as a first segment and a connecting line between the second terminal and the intersection is defined as a second segment;

the operation unit finds a first straight line that is parallel to the to the first branch and passes through the first terminal, and finds a second straight line that is perpendicular to the first straight line and passes through the second terminal, and the first and second straight lines intersect at an ellipsoid center;

the operation unit determines an ellipsoid by regarding a distance between the first terminal to the ellipsoid center and a distance between the second terminal and the ellipsoid center as ellipsoidal radiuses; and

the operation unit performs route planning for the AGV in the vision guidance region according to the first terminal, the second terminal and the ellipsoid.

9. The system according to claim 1, further comprising:

a control interface, for setting a task schedule or a destination position of the AGV through the operation unit.

10. The system according to claim 1, further comprising:

a plurality of tags, respectively disposed in a neighboring manner at a plurality of work stations;

wherein, the operation unit guides the AGV to move from the first terminal through the work stations to arrive the second terminal according to the vision guidance region associated image and the tags.

11. A method for guiding an AGV, the AGV being guided and moving on a guidance path when the AGV being on the guidance path, and departing from the guidance path to move in a vision guidance region, the method comprising:

capturing a vision guidance region associated image at least comprising an image of the vision guidance region;

determining whether the AGV is departed from the guidance path;

guiding the AGV by the guidance path according to the guidance path when the AGV is not departed form the guidance path; and

guiding the AGV according to the vision guidance region associated image when the AGV is departed from the guidance path;

wherein the guidance path comprises a first branch and a second branch, the first branch comprises a first terminal, and the second branch comprises a second terminal, and the vision guidance region is a non-guidance-path region between the first terminal and the second terminal;

when the AGV departs from the first terminal of the guidance path and enters the vision guidance region the AGV is guided by the operation unit rather than the guidance path until the AGV arrives at the second terminal, the operation unit guides the AGV according to the vision guidance region associated image when the AGV enters the vision guidance region.

12. The method according to claim 11, wherein the a first tag used to identify signal is disposed at the first terminal, a second tag used to identify signal is disposed at the second terminal, and a tag reader is disposed at the AGV and is for reading the first tag or the second tag as a trigger for a mechanism for guiding the AGV according to the vision guidance region associated image.

13. The method according to claim 11, wherein when the AGV reads the first tag or the second tag, a communication module informs an operation unit, and the operation unit determines whether the AGV is departed from the guidance path.

14. The method according to claim 11, wherein the vision guidance region associated image is the image of the vision guidance region, and the AGV is determined as being departed from the guidance path when the vision guidance region associated image displays the AGV.

15. The method according to claim 11, wherein the step of guiding the AGV according to the vision guidance region associated image visually calculates relative position information of the AGV and the second terminal according to the vision guidance region associated image, visually calculates included angle information between the AGV and the second branch according to the vision guidance region associated image, and performs route planning by the operation unit according to the relative information and the included angle information.

16. The method according to claim 11, wherein the step of guiding the AGV according to the vision guidance region associated image performs route planning for a shortest path in the vision guidance region for the AGV according to a minimum cut angle of the second branch.

17. The method according to claim 11, wherein the step of guiding the AGV according to the vision guidance region associated image comprises:

calculating an intersection of extension directions of the first branch and the second branch;

wherein a connecting line between the first terminal and the intersection is defined as a first segment and a connecting line between the second terminal and the intersection is defined as a second segment;

selecting a shorter segment of the first and second segments and utilizing a physical terminal of the shorter segment as a passing point;

finding a circle that is tangent to extension directions of the first branch and the second branch according to the passing point, with the circle being tangent to the extension direction of the second branch at a tangent point; and

performing route planning for the AGV in the vision guidance region according to the first terminal, the tangent point, the second terminal and the circle.

18. The method according to claim 11, wherein the step of guiding the AGV according to the vision guidance region associated image comprises:

calculating an intersection of extension directions of the first branch and the second branch;

wherein a connecting line between the first terminal and the intersection is defined as a first segment and a connecting line between the second terminal and the intersection is defined as a second segment;

finding a first straight line that is parallel to the to the first branch and passes through the first terminal, and finding a second straight line that is perpendicular to the first straight line and passes through the second terminal;

wherein the first and second straight lines intersect at an ellipsoid center;

determining an ellipsoid by regarding a distance between the first terminal to the ellipsoid center and a distance between the second terminal and the ellipsoid center as ellipsoidal radiuses; and

performing route planning for the AGV in the vision guidance region according to the first terminal, the second terminal and the ellipsoid.

19. The method according to claim 11, further comprising:

setting a task schedule or a destination position of the AGV.

20. The method according to claim 11, wherein a plurality of tags are respectively disposed in a neighboring manner at a plurality of work stations, and the step of guiding the AGV according to the vision guidance region associated image guides the AGV to move from the first terminal through the work stations to arrive the second terminal according to the vision guidance region associated image and the tags.