Fanned laser beam metrology system

• US 20070103698A1
• Filed: 11/09/2005
• Published: 05/10/2007
• Est. Priority Date: 11/09/2005
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Liu, Ketao, Liu, John, Bender, Douglas, Becker, Gregory, Sedivec, Peter, Guthrie, Richard, Lundgren, Mark
• Granted Patent: US 7,450,251 B2
• Time in Patent Office: Days
• US Class Current: 356/620
• 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: G01S 17/48 Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves

Abstract

Systems and techniques for laser metrology. A system may include a laser source and a fanning apparatus configured to generate a fanned laser beam. The fanned laser beam may be scanned across the surface of an object, and may reflect off a plurality of targets positioned on the surface. A position detection module may determine a position of the metrology targets based on the reflected beam.

Claims

1. A metrology system comprising:

a laser source;

a fanning apparatus to receive light from the laser source and to generate a fanned transmitted beam to be reflected as a reflected beam off of at least one metrology target positioned on a first surface of an object;

a position detection module configured to receive the reflected beam and to determine a position of the at least one metrology target based on the reflected beam; and

a scanner to generate relative motion between the fanned transmitted beam and the first surface of the object.

2. The metrology system of claim 1, wherein the fanning apparatus comprises at least one of a lens and a holographic grating.

3. The metrology system of claim 2, wherein the fanning apparatus comprises a cylindrical lens.

4. The metrology system of claim 1, further comprising the object comprising the at least one metrology target positioned on the first surface.

5. The metrology system of claim 1, wherein the position detection module comprises a position sensitive sensor to receive the reflected beam and to generate information indicative of an elevation angle for the at least one metrology target.

6. The metrology system of claim 1, wherein the scanner generates information indicative of an azimuthal angle, and wherein the position detection module is configured to receive the information indicative of the azimuthal angle.

7. The metrology system of claim 1, further comprising a ranging module, the ranging module configured to receive information indicative of the reflected beam and information indicative of the transmitted beam and to generate information indicative of a range of the at least one metrology target.

8. A method of determining a plurality of positions on a surface, comprising:

generating a substantially two-dimensional probe beam extending in a first direction;

scanning the probe beam across the surface in a second direction different than the first direction;

receiving a return beam reflected from a first target at a first position of the plurality of positions; and

determining the first position based at least on receiving the return beam.

9. The method of claim 8, wherein scanning the probe beam comprises scanning the probe beam with a scanner, and wherein determining the first position based at least on receiving the return beam comprises determining an azimuth angle of the first position based on a position of the scanner.

10. The method of claim 8, wherein determining the first position based at least on the receiving the return beam comprises determining an elevation angle of the first position based on a detected position of the return beam on a sensor.

11. The method of claim 10, wherein the sensor is a substantially one dimensional sensor.

12. The method of claim 8, wherein determining the first position based at least on receiving the return beam comprises determining a range of the first position.

13. The method of claim 12, wherein determining the range of the first position comprises determining a time between a beam generation pulse and receiving the return beam.

14. The method of claim 12, wherein determining the range of the first position comprises determining a phase relationship between the probe beam and the return beam.

16. The system of claim 13, further comprising a position sensor in communication with the scanner, wherein the position sensor is configured to detect a position of the scanner and to generate information indicative thereof.

17. The system of claim 16, wherein the position detection module is configured to determine the position of the first target using the information indicative of the position of the scanner.

15. A metrology system comprising:

a light source module configured to generate a substantially two dimensional probe beam, the probe beam extending in a first direction;

a scanner configured to scan the probe beam across a surface in a second direction different than the first direction, the surface including a plurality of reflective targets including a first target;

a substantially one dimensional sensor positioned and configured to receive return beams from the plurality of reflective targets, and wherein the sensor is configured to generate information indicative of a receiving position of each of the received return beams; and

a position detection module configured to determine a position of the first target in response to receiving a first return beam from the first target on the sensor at a first receiving position of the first return beam.

18. The system of claim 15, wherein the position detection module is configured to determine the position of the first target using information indicative of the probe beam and information indicative of the first return beam.

19. The system of claim 15, wherein the position detection module includes a correlation module in communication with the light source module.

20. The system of claim 15, wherein the position detection module includes processing electronics in communication with the sensor.

21. The system of claim 15, wherein the system is a space metrology system.

22. The system of claim 15, wherein the position detection module is configured to determine the position of the first target by determining a range based on information indicative of the probe beam and information indicative of the first return beam, by determining an azimuth angle based on information indicative of a position of the scanner, and by determining an elevation angle based on information indicative of the first receiving position.