APPARATUSES AND METHODS FOR ACCURATE STRUCTURE MARKING AND MARKING-ASSISTED STRUCTURE LOCATING

• US 20140375794A1
• Filed: 06/25/2013
• Published: 12/25/2014
• Est. Priority Date: 06/25/2013
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Singh, Navrit Pal
• Granted Patent: US 9,789,462 B2
• Time in Patent Office: Days
• US Class Current: 348/95
• CPC Class Codes: B01J 19/121 Coherent waves, e.g. laser beams lasers per se H01S3/00
• CPC Class Codes: B23K 26/0626 Energy control of the laser beam B23K26/0622 takes precedence
• CPC Class Codes: B23K 26/082 Scanning systems, i.e. devices involving movement of the laser beam relative to the laser head
• CPC Class Codes: G01B 11/14 for measuring distance or clearance between spaced objects or spaced apertures G01B11/26 takes precedence; rangefinders G01C3/00
• CPC Class Codes: G01B 11/24 for measuring contours or curvatures
• CPC Class Codes: G01C 3/08 Use of electric radiation detectors
• CPC Class Codes: G05B 19/40937 concerning programming of machining or material parameters, pocket machining
• CPC Class Codes: G05B 2219/32025 Automatic marking of article
• CPC Class Codes: G05B 2219/45134 Marking
• CPC Class Codes: G06T 7/0004 Industrial image inspection
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

Working equipment includes a tool configured to work a structure at a working location thereon, with the structure having an applied marking at a known location with a known relationship with the working location. A computer system is configured to determine placement of the structure, and accordingly position the tool into at least partial alignment with the working location, and which in at least one instance, the tool is aligned with a second, offset location. A camera is configured to capture an image of the structure and including the marking, and further including the second location with which the tool is aligned. And the computer system is configured to process the image to locate the working location, reposition the tool from the second location and into greater alignment with the located working location, and control the repositioned tool to work the structure at the located working location.

Claims

1. A laser-marking system comprising:

a laser source configured to emit a laser beam;

a steering assembly configured to steer the laser beam onto a structure to be worked; and

a computer system coupled to the laser source and steering assembly, and configured to direct operation of the laser source to emit the laser beam with one or more controllable parameters to apply a permanent marking to the structure,

wherein the computer system is also configured to direct operation of the steering assembly to steer the laser beam to a known location on the structure at which to apply the marking, the respective location having a known relationship with a working location at which to work the structure.

2. The laser-marking system of claim 1, wherein the steering assembly comprises:

a galvanometer coupled to a mirror configured to reflect the laser beam, the galvanometer and mirror being controllably rotatable to steer the laser beam in a particular direction; and

an optical rotary encoder coupled to the computer system and galvanometer, and configured to measure an angular position of the galvanometer, and

wherein the computer system is configured to determine a location of the laser beam on the structure based on the measurement, and steer the laser beam to the known location based on the determined location.

3. The laser-marking system of claim 1 further comprising:

a camera or laser scanner coupled to the computer system, the camera being configured to capture an image of at least a portion of the structure and including one or more targets on or proximate the structure, and the laser scanner being configured to measure points on a surface of the structure from which a 3D model of the structure is generatable,

wherein the computer system is configured to process the image or 3D model to determine placement of the structure, and locate the known location at which to apply the marking based on the placement.

4. The laser-marking system of claim 1, wherein the known location is a desired location, and in at least one instance the marking is offset from the desired location, and wherein the laser-marking system further comprises:

a camera coupled to the computer system and configured to capture an image of at least a portion of the structure and including the desired location and marking,

wherein the computer system is configured to process the image to locate the desired location, and determine an offset of the marking from the located desired location.

5. The laser-marking system of claim 4, wherein the camera has a field of view steerable by the steering assembly, the computer system being configured to direct operation of the steering assembly to steer the field of view to one or more areas within which one or more targets on or proximate the structure are located,

wherein for the one or more areas, the camera is configured to capture one or more images of at least a portion of the structure and including the one or more targets, and

wherein the computer system is configured to process the one or more images to determine placement of the structure, and locate the known location at which to apply the marking based on the placement.

6. The laser-marking system of claim 1 further comprising:

a second laser source configured to project a laser image on the structure at the location before the laser beam is emitted to apply the permanent marking to the structure at the respective location.

7. The laser-marking system of claim 1 further comprising:

a laser tracker configured to project one or more steerable laser beams onto retro-reflective targets on or proximate the structure at known locations, and provide measurements of reflected one or more beams from the targets for determination of placement of the structure.

8. The laser-marking system of claim 1 further comprising:

a range sensor configured to provide range measurements between the laser-marking system and structure for calculation of an initial focus point or focal length for operation of the laser source, or dynamic adjustment of the focal length.

9. The laser-marking system of claim 1 further comprising:

a vibration sensor configured to provide measurements of vibration of the structure, or the laser-marking system including the vibration sensor disposed thereon, for compensation of vibrational movement of the structure or laser-marking system.

10. A working equipment comprising:

a tool configured to work a structure at a working location thereon, the structure having a marking applied thereto at a known location with a known relationship with the working location;

a computer system coupled to the tool and configured to determine placement of the structure, and position the tool into at least partial alignment with the working location according to the placement, the tool in at least one instance being aligned with a second location offset from the working location; and

a camera coupled of the computer system and configured to capture an image of at least a portion of the structure and including the marking, and further including the second location with which the tool is aligned,

wherein the computer system is configured to process the image to locate the working location, reposition the tool from the second location and into greater alignment with the located working location, and control the repositioned tool to work the structure at the located working location.

11. The working equipment of claim 10, wherein the camera is a second camera configured to capture a second image, and the working equipment further comprises:

a first camera coupled to the computer system and configured to capture a first image of at least a portion of the structure and including one or more targets on or proximate the structure,

wherein the computer system is configured to process the first image to thereby determine the placement.

12. The working equipment of claim 10 further comprising:

a movable end effector assembly coupled to the computer system, and including an end effector and the tool, wherein the camera is secured to the end effector assembly, and

wherein the computer system being configured to position the tool includes being configured to position the end effector assembly and thereby the tool, the camera also being thereby positioned such that a field of view of the camera encompasses the marking.

13. The working equipment of claim 10, wherein the camera has a field of view divided into a plurality of concentric zones of increasing size about the second location with which the tool is aligned, the zones including a first zone that defines an acceptable offset, and a larger second zone located outside the first zone that defines an unacceptable offset, and

wherein the computer system is configured to control the tool to work the structure without repositioning in an instance in which the located working location is within the first zone, or reposition the tool before controlling the tool to work the structure in an instance in which the located working location is within the second zone.

14. A method comprising:

directing operation of a laser source to emit a laser beam onto a structure to be worked, the laser beam being emitted with one or more controllable parameters to apply a permanent marking to the structure; and

directing operation of a steering assembly to steer the laser beam to a known location on the structure at which to apply the marking, the respective location having a known relationship with a working location at which to work the structure.

15. The method of claim 14, wherein directing operation of the steering assembly comprises:

controllably rotating a galvanometer coupled to a mirror configured to reflect the laser beam, the galvanometer and mirror being controllably rotated to steer the laser beam in a particular direction;

measuring an angular position of the galvanometer by an optical rotary encoder coupled to the galvanometer; and

determining a location of the laser beam on the structure based on the measurement, and steering the laser beam to the known location based on the determined location.

16. The method of claim 14 further comprising:

capturing an image of at least a portion of the structure and including one or more targets on or proximate the structure, or measuring points on a surface of the structure from which a 3D model of the structure is generatable; and

processing the image or 3D model to determine placement of the structure, and locating the known location at which to apply the marking based on the placement.

17. The method of claim 14, wherein the known location is a desired location, and in at least one instance the marking is offset from the desired location, and wherein the method further comprises:

capturing an image of at least a portion of the structure and including the desired location and marking; and

processing the image to locate the desired location, and determining an offset of the marking from the located desired location.

18. The method of claim 17, wherein the image is captured by a camera having a field of view steerable by the steering assembly, and the method further comprises:

directing operation of the steering assembly to steer the field of view to one or more areas within which one or more targets on or proximate the structure are located;

capturing for the one or more areas, one or more images of at least a portion of the structure and including the one or more targets; and

processing the one or more images to determine placement of the structure, and locating the known location at which to apply the marking based on the placement.

19. The method of claim 14 further comprising:

projecting a laser image on the structure at the location before the laser beam is emitted to apply the permanent marking to the structure at the respective location.

20. The method of claim 14 further comprising:

projecting one or more steerable laser beams onto retro-reflective targets on or proximate the structure at known locations, and providing measurements of reflected one or more beams from the targets for determination of placement of the structure.

21. The method of claim 14, wherein the laser source and steering assembly are components of a laser-marking system, and wherein the method further comprises:

providing range measurements between the laser-marking system and structure for calculation of an initial focus point or focal length for operation of the laser source, or dynamic adjustment of the focal length.

22. The method of claim 14, wherein the laser source and steering assembly are components of a laser-marking system, and wherein the method further comprises:

providing by a vibration sensor, measurements of vibration of the structure, or the laser-marking system including the vibration sensor disposed thereon, for compensation of vibrational movement of the structure or laser-marking system.

23. A method comprising:

determining placement of a structure having a marking applied thereto at a known location with a known relationship with a working location thereon;

positioning a tool into at least partial alignment with the working location according to the placement, the tool in at least one instance being aligned with a second location offset from the working location;

capturing an image of at least a portion of the structure and including the marking, and further including the second location with which the tool is aligned; and

processing the image to locate the working location, repositioning the tool from the second location and into greater alignment with the located working location, and controlling the repositioned tool to work the structure at the located working location.

24. The method of claim 23, wherein the image is a second image captured by a second camera, and wherein determining the placement comprises:

capturing by a first camera, a first image of at least a portion of the structure and including one or more targets on or proximate the structure; and

processing the first image to thereby determine the placement.

25. The method of claim 23, wherein a movable end effector assembly includes an end effector and the tool, wherein the image is captured by a camera secured to the end effector assembly, and

wherein positioning the tool includes positioning the end effector assembly and thereby the tool, the camera also being thereby positioned such that a field of view of the camera encompasses the marking.

26. The method of claim 23, wherein the image is captured by a camera having a field of view divided into a plurality of concentric zones of increasing size about the second location with which the tool is aligned, the zones including a first zone that defines an acceptable offset, and a larger second zone located outside the first zone that defines an unacceptable offset, and

wherein repositioning the tool and controlling the repositioned tool to work the structure includes controlling the tool to work the structure without repositioning in an instance in which the located working location is within the first zone, or repositioning the tool before controlling the tool to work the structure in an instance in which the located working location is within the second zone.