Laser-etching and machine-vision positioning system

Patent metadata

Field	Value
Publication number	US-11084123-B2
Application number	US-201916562387-A
Country	US
Kind code	B2
Filing date	Sep 5, 2019
Priority date	Sep 5, 2019
Publication date	Aug 10, 2021
Grant date	Aug 10, 2021

Abstract

Systems, methods and computer program products for laser etching and robotic machining of large workpieces are disclosed. An example system includes a first ring of lasers configured to etch longitudinal gridlines on a workpiece, a second ring of lasers configured to etch circumferential gridlines on the workpiece, where the longitudinal gridlines and the circumferential gridlines define a working grid on the workpiece, and a machine vision system to scan the working grid and compare the working grid to a reference grid in a computer model of the workpiece and to determine offsets between the working grid and the reference grid for positioning a robotic machining tool.

First claim

What is claimed is:

1. A system, comprising:
a first ring of lasers, comprising a first plurality of lasers, configured to etch longitudinal gridlines on a workpiece;
a second ring of lasers, comprising a second plurality of lasers, configured to etch circumferential gridlines on the workpiece, wherein the longitudinal gridlines and the circumferential gridlines define a working grid on the workpiece; and
a machine vision system to scan the working grid and compare the working grid to a reference grid in a computer model of the workpiece, and to determine offsets between the working grid and the reference grid.

2. The system of claim 1 , wherein each of the first plurality of lasers and each of the second plurality of lasers comprises a distance sensing and focusing system to focus each laser on the workpiece.

3. The system of claim 1 , further comprising a rail system to support and position the first ring of lasers and the second ring of lasers with respect to the workpiece.

4. The system of claim 1 , wherein the second ring of lasers is configured to rotate with respect to the first ring of lasers and with respect to the workpiece, to etch the circumferential gridlines.

5. The system of claim 1 , wherein an origin of the working grid is indexed to a datum of the workpiece.

6. The system of claim 1 , wherein an origin of the working grid is indexed to the reference grid.

7. The system of claim 3 , further comprising a robotic drive system coupled with the machine vision system and the rail system to translate the first ring of lasers and the second ring of lasers with respect to the workpiece, and to rotate the second ring of lasers with respect to the first ring of lasers and the workpiece.

8. The system of claim 1 , further comprising a robotic tool coupled with the machine vision system, to perform machining operations on the workpiece based on the offsets between the working grid and the reference grid.

9. The system of claim 1 , further comprising a gantry to support the workpiece and the rail system.

10. The system of claim 7 , wherein the working grid comprises a plurality of grid cells, wherein the second ring of lasers and the robotic drive are configured to etch a location code in each of the plurality of grid cells.

11. A method, comprising:
etching longitudinal gridlines on a workpiece with a first ring of lasers comprising a first plurality of lasers;
etching circumferential gridlines on the workpiece with a second ring of lasers comprising a second plurality of lasers, wherein the longitudinal gridlines and the circumferential gridlines define a working grid on the workpiece;
scanning the working grid with a machine-vision system;
comparing the working grid to a reference grid in a computer model of the workpiece; and
determining offsets between the working grid and the reference grid.

12. The method of claim 11 , further comprising:
detecting a distance between the workpiece and each laser in the first ring of lasers and the second ring of lasers; and
focusing each laser in the first ring of lasers and the second ring of lasers on the workpiece.

13. The method of claim 11 , wherein,
etching the longitudinal gridlines comprises traversing the workpiece with the first ring of lasers on a rail system with a robotic drive, and wherein
etching the circumferential gridlines comprises rotating the second ring of lasers around the workpiece with the robotic drive.

14. The method of claim 11 , further comprising indexing the working grid to the reference grid.

15. The method of claim 11 , further comprising indexing the working grid to a datum of the workpiece.

16. The method of claim 11 , comprising:
positioning a robotic tool at a node of the working grid with the machine-vision system;
correcting the position of the robotic tool for the offsets between the working grid and the reference grid; and
machining the workpiece at the corrected position of the robotic tool.

17. The method of claim 13 , wherein the working grid comprises a plurality of grid cells, the method further comprising:
positioning the second ring of lasers with the machine vision system and the robotic drive; and
etching a location code in each of the plurality of grid cells with the second ring of lasers.

18. The method of claim 17 , further comprising:
reading the location code of a selected grid cell with the machine vision system;
positioning a robotic tool in the selected grid cell;
correcting the positioning of the robotic tool for the offsets between the working grid and the reference grid; and
machining the workpiece at the corrected position of the robotic tool.

19. An apparatus, comprising a non-transitory, computer-readable medium having instructions therein that, when executed by a processor in a laser etching system, cause the processor to control operations, comprising:
etching longitudinal gridlines on a workpiece comprising one of a cylindrical or semi-cylindrical body with a first ring of lasers comprising a first plurality of lasers;
etching circumferential gridlines on the workpiece with a second ring of lasers comprising a second plurality of lasers, wherein the longitudinal gridlines and the circumferential gridlines define a working grid on the workpiece;
scanning the working grid with a machine vision system;
comparing the working grid to a reference grid in a computer model of the workpiece; and
determining offsets between the working grid and the reference grid.

20. The apparatus of claim 19 , further comprising:
positioning a robotic tool at a node of the working grid with the machine-vision system;
correcting the position of the robotic tool for the offsets between the working grid and the reference grid; and
machining the workpiece at the corrected position of the robotic tool.

Assignees

• Boeing Co

Inventors

• Aske James Alan
• Berkey Tyler Emerson
• Miller John Eric

Classifications

• B23K26/10

  using a fixed support {, i.e. involving moving the laser beam} · CPC title

• B23K26/032

  using optical means · CPC title

• B23K26/042

  Automatically aligning the laser beam · CPC title

• B23K26/362

  Laser etching · CPC title

• B23K26/046 Primary

  Automatically focusing the laser beam · CPC title