Method and system for ply boundary detection

1 . A method of detecting edges of a ply, the method comprising:

projecting, from a first position onto a surface of the ply, a laser line spanning across an edge of the ply;

scanning the laser line on the first ply with a galvanometer;

recording, from a second position angularly offset from the first position, an image of the laser line; and

determining, using the image of the laser line, a location of the edge of the ply.

2 . The method of claim 1 , wherein projecting the laser line is performed using a laser projector.

3 . The method of claim 1 , wherein recording an image of the laser line includes:

imaging light reflected from the surface of the ply onto a camera.

4 . The method of claim 3 , wherein scanning a laser beam includes:

generating a laser beam.

5 . The method of claim 4 , wherein projecting the laser line and recording an image of the laser line are performed from fixed positions.

6 . The method of claim 1 , wherein:

recording the image of the laser line includes generating a profile of the laser line, and

determining the location of the edge includes detecting a change in the profile.

7 . The method of claim 1 , further comprising:

storing a set of data defining a desired, nominal location of the edge of the ply; and

comparing the location of the edge of the ply based on the image of the laser line with the nominal location.

8 . The method of claim 1 , wherein determining the location of the edge includes:

isolating the laser line in the image based on contrast between the laser line and the ply.

9 . The method of claim 1 , wherein:

recording the image of the laser line includes recording a profile of the edge, and

determining the location of the edge includes measuring a depth of the edge.

10 . A method of measuring a gap between a first ply and a second ply, the method comprising:

projecting a laser line from a laser projector in a first position onto the first ply and the second ply spanning the gap;

scanning the laser line on the first ply and the second ply with a galvanometer;

recording an image of the laser line from a second position angularly offset from the first position;

detecting a location of edges of the first ply and the second ply using the image; and

determining a width of the gap based on the location of the edges.

11 . The method of claim 10 , wherein each of the first position and the second position are fixed relative to the first ply and the second ply.

12 . The method of claim 10 , wherein the first position and the second position are angularly offset from each other by a parallax angle.

13 . The method of claim 10 , wherein recording an image of the laser line includes:

generating a laser beam.

14 . The method of claim 10 , wherein:

recording the image of the laser line includes generating a profile of the laser line, and

detecting a location of the edges includes detecting a change in the profile.

15 . The method of claim 10 , wherein detecting a location of the edges includes measuring a depth of the laser line spanning across the gap.

16 . The method of claim 10 , further comprising:

storing a set of data defining a desired, nominal width of the gap; and

comparing the width of the gap with the desired, nominal width.

17 . The method of claim 10 , wherein detecting a location of the edges includes isolating the laser line in the image based on contrast between the laser line and the first ply and the second ply.

18 . A system configured to detect a location of an edge of a ply, wherein the system comprises:

a laser projector configured to project a laser line onto the ply;

a galvanometer configured to scan the laser line on the ply; and

an imaging system angularly offset from the laser projector by a parallax angle.

19 . The system of claim 18 , wherein each of the laser projector and the imaging system is mounted in a fixed position relative to the ply.

20 . The system of claim 18 , wherein the imaging system includes:

a camera configured to recorded images; and

a second galvanometer configured to direct light into the camera that is reflected from the ply and originates from the laser beam.

21 . The system of claim 18 , further comprising:

a controller configured to coordinate operation of the laser projector with the imaging system.

22 . The system of claim 21 , further comprising:

a memory coupled with the controller and configured to store image data representing a desired, nominal location of the edge of the ply.