System and method for identifying a feature of a workpiece

• US 8,050,486 B2
• Filed: 05/22/2007
• Issued: 11/01/2011
• Est. Priority Date: 05/16/2006
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Walton, Steven R.
• Primary Examiner(s): CHANG, JON CARLTON
• Application Number:
  US11/805,156
• Publication Number:
  US 20070271064A1
• Time in Patent Office: 1,624 Days
• Field of Search: 382/141, 382/154, 356/603, 356/604, 356/606, 356/607, 356/610, 356/237.2, 356/237.3
• US Class Current: 382/141
• CPC Class Codes: B29C 70/32 on a rotating mould, former or core
• CPC Class Codes: B29C 70/388 Tape placement heads, e.g. component parts, details or accessories
• CPC Class Codes: B29L 2031/3082 Fuselages
• CPC Class Codes: G01B 11/245 using a plurality of fixed, simultaneously operating transducers G01B11/2408 - G01B11/2425, G01B11/255 take precedence
• CPC Class Codes: G01B 11/25 by projecting a pattern, e.g. one or more lines, moiré fringes on the object G01B11/255 takes precedence ; image analysis for depth or shape recovery G06T7/50
• CPC Class Codes: G01N 2021/8472 Investigation of composite materials
• CPC Class Codes: G01N 21/88 Investigating the presence of flaws or contamination
• CPC Class Codes: G01N 21/892 characterised by the flaw, defect or object feature examined

Abstract

A feature of a workpiece can be identified. Two-dimensional data of at least a region of a workpiece and three-dimensional data of a portion of the region of the workpiece are acquired, such as by illuminating at least the region with at least a first light source disposed at a first angle of incidence relative to a plane of the region and illuminating the portion with a second light source, such as at least one laser, disposed at a second angle of incidence greater than the first angle of incidence. An estimated location of an attribute of a feature of the workpiece is determined from the three-dimensional data, and the feature is identified by analyzing the two-dimensional data in an area surrounding the estimated location of the attribute. Attributes of features can include without limitation a point along a line of an edge.

Claims

1. A method for identifying a feature of a workpiece, the method comprising:

acquiring two-dimensional data of at least a region of a workpiece;

acquiring three-dimensional data of a portion of the region of the workpiece;

determining an estimated location of an attribute of a feature of the workpiece from the three-dimensional data; and

identifying the feature by analyzing the two-dimensional data in an area surrounding the estimated location of the attribute, wherein identifying the feature includes performing a plurality of iterations of analyzing the two-dimensional data, wherein a first iteration analyzes the two-dimensional data in a first area bounded along a first dimension with a first lineal measurement and a second dimension with a second lineal measurement, and wherein a second iteration analyzes the two-dimensional data in a second area bounded along the first dimension with a third lineal measurement that is longer than the first lineal measurement and the second dimension having a fourth lineal measurement that is shorter than the second lineal measurement.

2. The method of claim 1, wherein:

the feature includes an edge; and

the attribute includes a point along a line.

3. The method of claim 1, wherein:

the feature includes a hole; and

the attribute includes a plurality of points along a circle.

4. The method of claim 1, wherein:

the feature includes a chamfered hole; and

the attribute includes a plurality of points along two concentric circles.

5. The method of claim 1, wherein acquiring the two-dimensional data includes:

illuminating at least the region of the workpiece with at least a first light source that is disposed at a first angle of incidence relative to a plane of the region; and

sensing an image of the region.

6. The method of claim 5, wherein acquiring the three-dimensional data includes:

illuminating the portion of the region of the workpiece with a second light source that is disposed at a second angle of incidence relative to the plane of the region, the second angle of incidence being greater than the first angle of incidence; and

sensing an image of the portion of the region.

7. The method of claim 6, wherein illuminating the portion of the region of the workpiece includes directing at least one laser beam onto the portion of the region of the workpiece.

8. The method of claim 7, wherein determining the estimated location of the attribute includes analyzing a plurality of steps along at least one line illuminated by the at least one laser beam.

9. A system for identifying a feature of a workpiece, the system comprising:

a first light source configured to illuminate at least a region of a workpiece;

a second light source configured to illuminate a portion of the region of the workpiece;

a sensor configured to sense an image of the region and the portion of the region; and

a processor operatively coupled to the sensor, the processor including;

a first component configured to determine an estimated location of an attribute of a feature of the workpiece from three-dimensional data regarding the portion of the region of the workpiece; and

a second component configured to identify the feature by analyzing two-dimensional data regarding the region in an area surrounding the estimated location of the attribute.

10. The system of claim 9, wherein:

the first light source is disposed at a first angle of incidence relative to a plane of the region; and

the second light source is disposed at a second angle of incidence relative to the plane of the region, the second angle of incidence being greater than the first angle of incidence.

11. The system of claim 9, wherein the first light source includes first and second lighting assemblies disposed towards first and second ends of the region, respectively.

12. The system of claim 9, wherein the second light source includes at least one laser.

13. The system of claim 9, wherein the sensor includes a camera.

14. A method of detecting an edge, the method comprising:

illuminating at least a region of a workpiece with a pair of first light sources that are disposed at a first angle of incidence relative to a plane of the region;

illuminating a portion of the region of the workpiece with a second light source that is disposed at a second angle of incidence relative to the plane of the region, the second angle of incidence being greater than the first angle of incidence;

capturing a frame of information;

determining an estimated location of a point along a line defining an edge within the workpiece from three-dimensional data from the frame of information; and

refining location of the edge by analyzing two-dimensional data from the frame of information in an area surrounding the estimated location of the point.

15. The method of claim 14, further comprising inputting into two-dimensional analysis a plurality of estimated locations of points along a plurality of lines that define a plurality of edges.

16. The method of claim 15, wherein analyzing the two-dimensional data includes formulating a plurality of candidate lines from the plurality of points at the plurality of estimated locations.

17. The method of claim 16, wherein analyzing the two-dimensional data further includes determining a median angle of the plurality of candidate lines.

18. The method of claim 17, wherein analyzing the two-dimensional data further includes comparing an angle of each candidate line with the median angle of the plurality of candidate lines.

19. The method of claim 18, wherein analyzing the two-dimensional data further includes invalidating a candidate line when its angle exceeds the median angle.

20. A memory device storing computer software program code that is executable by a processor to:

analyzing analyze three-dimensional information to determine a plurality of estimated locations of points along a plurality of lines defining a plurality of edges;

analyze two-dimensional information in a plurality of areas surrounding the estimated locations of the points to refine locations of the edges;

formulate a plurality of candidate lines from the points at the plurality of estimated locations; and

determine a median angle of the plurality of candidate lines.

21. The memory device of claim 20, wherein the computer software program code is further executable by the processor to compare an angle of each candidate line with the median angle of the plurality of candidate lines.

22. The memory device of claim 21, wherein the computer software program code is further executable by the processor to invalidate a candidate line when its angle exceeds the median angle.

23. A head assembly for performing a manufacturing operation on a workpiece, the head assembly comprising:

a tool moveable relative to a workpiece and configured to perform a manufacturing operation on the workpiece; and

a monitoring unit operatively coupled to and moveable with the tool relative to the workpiece, the monitoring unit including;

first and second lighting assemblies disposed towards first and second sides of the monitoring unit, respectively, the first and second lighting assemblies being configured to illuminate at least a region of the workpiece;

a laser assembly configured to illuminate a portion of the region of the workpiece upon which the tool has performed the manufacturing operation;

a sensor configured to sense an image of the region and the portion of the region; and

a processor operatively coupled to the sensor, the processor including;

a first component configured to determine an estimated location of an attribute of a feature of the workpiece from three-dimensional data regarding the portion of the region of the workpiece; and

a second component configured to identify the feature by analyzing two-dimensional data regarding the region in an area surrounding the estimated location of the attribute.

24. The head assembly of claim 23, wherein the tool is configured to perform an application of a composite tape onto the workpiece, and wherein the monitoring unit is configured to illuminate at least a region of the composite tape.

25. The head assembly of claim 24, wherein the tool includes:

a spindle configured to support a supply of the composite tape; and

a feed assembly configured to feed the composite tape from the supply to the workpiece, the feed assembly having a rotatable compaction roller configured to apply the composite tape onto the workpiece.

26. The head assembly of claim 23, wherein:

the first and second lighting assemblies are disposed at a first angle of incidence relative to a plane of the region; and

the laser assembly is disposed at a second angle of incidence relative to the plane of the region, the second angle of incidence being greater than the first angle of incidence.

27. The head assembly of claim 23, wherein the sensor includes a camera.

28. A system for performing a manufacturing operation on a workpiece, the system comprising:

at least one head assembly configured to perform a manufacturing operation on a workpiece, the head assembly including;

a tool moveable relative to a workpiece and configured to perform the manufacturing operation on the workpiece; and

a monitoring unit operatively coupled to and moveable with the tool relative to the workpiece, the monitoring unit including;

first and second lighting assemblies disposed towards first and second sides of the monitoring unit, respectively, the first and second lighting assemblies being configured to illuminate at least a region of the workpiece;

a laser assembly configured to illuminate a portion of the region of the workpiece upon which the tool has performed the manufacturing operation;

a sensor configured to sense an image of the region and the portion of the region; and

a processor operatively coupled to the sensor, the processor including;

a first component configured to determine an estimated location of an attribute of a feature of the workpiece from three-dimensional data regarding the portion of the region of the workpiece; and

a second component configured to identify the feature by analyzing two-dimensional data regarding the region in an area surrounding the estimated location of the attribute; and

a translation platform coupled to the at least one head assembly, the translation platform being configured to operatively position the at least one head assembly proximate the workpiece and to systematically move the at least one head assembly along a translation path proximate the workpiece.

29. The system of claim 28, wherein the tool is configured to perforin an application of a composite tape onto the workpiece, and wherein the monitoring unit is configured to illuminate at least a region of the composite tape.

30. The system of claim 29, wherein the tool includes:

a spindle configured to support a supply of the composite tape; and

a feed assembly configured to feed the composite tape from the supply to the workpiece, the feed assembly having a rotatable compaction roller configured to apply the composite tape onto the workpiece.

31. The system of claim 28, wherein:

the first and second lighting assemblies are disposed at a first angle of incidence relative to a plane of the region; and

the laser assembly is disposed at a second angle of incidence relative to the plane of the region, the second angle of incidence being greater than the first angle of incidence.

32. The system of claim 28, wherein the sensor includes a camera.

33. A method of performing a manufacturing operation on a workpiece, the method comprising:

performing a manufacturing operation on a portion of a workpiece using a tool moveable relative to the workpiece;

simultaneously with performing the manufacturing operation, translating the tool relative to the workpiece; and

simultaneously with performing the manufacturing operation, monitoring a portion of the workpiece upon which the tool has performed the manufacturing operation, wherein the monitoring includes;

acquiring two-dimensional data of at least a region of the workpiece;

acquiring three-dimensional data of a portion of the region of the workpiece;

determining an estimated location of an attribute of a feature of the workpiece from the three-dimensional data; and

identifying the feature by analyzing the two-dimensional data in an area surrounding the estimated location of the attribute.

34. The method of claim 33, wherein performing the manufacturing operation includes applying a composite tape onto the workpiece.

35. The method of claim 34, wherein performing the manufacturing operation further includes feeding the composite tape from a tape supply to a compaction roller, and wherein applying the composite tape includes compacting the composite tape onto the workpiece using the compaction roller.

36. The method of claim 33, wherein acquiring the two-dimensional data includes:

illuminating at least the region of the workpiece with first and second lighting assemblies that are disposed at a first angle of incidence relative to a plane of the region; and

sensing an image of the region.

37. The method of claim 36, wherein acquiring the three-dimensional data includes:

illuminating the portion of the region of the workpiece with a laser assembly that is disposed at a second angle of incidence relative to the plane of the region, the second angle of incidence being greater than the first angle of incidence; and

sensing an image of the portion of the region.

38. A method comprising:

acquiring two-dimensional data of at least a region of a workpiece, wherein acquiring the two-dimensional data includes;

illuminating at least the region of the workpiece with at least a first light source that is disposed at a first angle of incidence relative to a plane of the region; and

sensing an image of the region;

acquiring three-dimensional data of a portion of the region of the workpiece, wherein acquiring the three-dimensional data includes;

illuminating the portion of the region of the workpiece with a second light source that is disposed at a second angle of incidence relative to the plane of the region, the second angle of incidence being greater than the first angle of incidence; and

sensing an image of the portion of the region;

determining an estimated location of an attribute of a feature of the workpiece from the three-dimensional data; and

identifying the feature by analyzing the two-dimensional data in an area surrounding the estimated location of the attribute.