Apparatus for determining relative positioning of objects and related methods

• US 6,741,364 B2
• Filed: 08/13/2002
• Issued: 05/25/2004
• Est. Priority Date: 08/13/2002
• Status: Expired due to Fees

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Montgomery, Robert M., Lange, Michael Ray
• Primary Examiner(s): Font, Frank G.
• Assistant Examiner(s): Nguyen, Sang H.
• Application Number:
  US10/217,945
• Publication Number:
  US 20040032596A1
• Time in Patent Office: 651 Days
• Field of Search: 356/139.03, 356/139.05, 356/139.06, 356/614, 356/620, 356/622-623, 356/625, 356/634-635, 250/559.29, 250/237.G, 700/59
• US Class Current: 356/622
• CPC Class Codes: G01B 11/00 Measuring arrangements characterised by the use of optical techniques

Abstract

An apparatus for determining relative positioning of first and second objects being relatively movable may include a laser source carried by the first object for generating a source laser beam toward the second object, and a target optical element carried by the second object for generating a first reflected beam and a second diverging reflected beam from the source laser beam. Furthermore, a detector may be carried by the first object for detecting the first reflected beam and the second diverging reflected beam. A controller may also be connected to the detector for determining a range between the detector and target optical element based upon a size of the second diverging reflected beam. The controller may also determine at least one other positional degree of freedom quantity (e.g., lateral/vertical displacement, pitch angle, yaw angle, and/or roll angle) based upon the first reflected beam and the second diverging reflected beam.

Claims

1. An apparatus for determining relative positioning of first and second objects being relatively movable, the apparatus comprising:

a laser source carried by the first object for generating a source laser beam toward the second object;

a target optical element carried by the second object for generating a first reflected beam and a second diverging reflected beam from the source laser beam;

a detector carried by the first object for detecting the first reflected beam and the second diverging reflected beam; and

a controller connected to said detector for determining a range between said detector and target optical element based upon a size of the second diverging reflected beam and for determining at least one other positional degree of freedom quantity based upon the first reflected beam and the second diverging reflected beam.

2. The apparatus of claim 1 wherein said controller determines the at least one other positional degree of freedom quantity by calculating a first centroid for the first reflected beam and a second centroid for the second diverging reflected beam, and determining positions of the first and second centroids.

3. The apparatus of claim 1 wherein said controller defines vertical and lateral reference coordinates;

and wherein the at least one other positional degree of freedom quantity comprises at least one of vertical displacement, lateral displacement, pitch angle, and yaw angle.

4. The apparatus of claim 1 wherein said controller further defines a first roll angle reference pattern;

wherein said target optical element has a pattern generator associated therewith for imparting a second roll angle reference pattern to one of the first reflected beam and second diverging reflected beam; and

wherein the at least one other positional degree of freedom quantity comprises a roll angle determined based upon the first and second roll angle reference patterns.

5. The apparatus of claim 4 wherein said pattern generator comprises a diffractive optical element (DOE).

6. The apparatus of claim 1 wherein said controller further determines at least one of alignment error data and second object position data based upon the determined range and the determined at least one other positional degree of freedom quantity.

7. The apparatus of claim 1 wherein said target optical element comprises a lens.

8. The apparatus of claim 7 wherein said lens has a flat rear surface and a convex front surface.

9. The apparatus of claim 8 further comprising a partially reflective coating on the front surface and a more reflective coating on the rear surface.

10. The apparatus of claim 1 wherein said target optical element comprises a corner cube.

11. The apparatus of claim 1 wherein the second diverging beam comprises a plurality of diffracted rays.

12. The apparatus of claim 1 wherein said laser source comprises a laser emitter and a beam splitter downstream therefrom.

13. The apparatus of claim 1 wherein said detector comprises an array of pixel elements.

14. The apparatus of claim 1 further comprising a reference indicator carried by the first object for aligning said laser source.

15. The apparatus of claim 1 wherein said controller controls said laser source to provide a desired signal level at said detector.

16. The apparatus of claim 1 further comprising an optical filter associated with said detector.

17. An apparatus for determining relative positioning of first and second objects being relatively movable, the apparatus comprising:

a laser emitter and a beam splitter downstream therefrom both carried by the first object and cooperating to generate a source laser beam toward the second object;

a lens carried by the second object for generating a first reflected beam and a second diverging reflected beam from the source laser beam;

a detector carried by the first object for detecting the first reflected beam and the second diverging reflected beam; and

a controller connected to said detector for determining a range between said detector and lens based upon a size of the second diverging reflected beam.

18. The apparatus of claim 17 wherein said controller is also for determining at least one other positional degree of freedom quantity based upon the first reflected beam and the second diverging reflected beam.

19. The apparatus of claim 18 wherein said controller determines the at least one other positional degree of freedom quantity by calculating a first centroid for the first reflected beam and a second centroid for the second diverging reflected beam, and determining positions of the first and second centroids.

20. The apparatus of claim 18 wherein said controller defines vertical and lateral reference coordinates;

and wherein the at least one other positional degree of freedom quantity comprises at least one of vertical displacement, lateral displacement, pitch angle, and yaw angle.

21. The apparatus of claim 18 wherein said controller further determines at least one of alignment error data and second object position data based upon the determined range and the determined at least one other positional degree of freedom quantity.

22. The apparatus of claim 18 wherein said controller further defines a first roll angle reference pattern;

wherein said lens has a pattern generator associated therewith for imparting a second roll angle reference pattern to one of the first reflected beam and second diverging reflected beam; and

wherein the at least one other positional degree of freedom quantity comprises a roll angle determined based upon the first and second roll angle reference patterns.

23. The apparatus of claim 22 wherein said pattern generator comprises a diffractive optical element (DOE).

24. The apparatus of claim 17 wherein said lens has a flat rear surface and a convex front surface.

25. The apparatus of claim 24 further comprising a partially reflective coating on the front surface and a more reflective coating on the rear surface.

26. An apparatus for determining relative positioning of first and second objects being relatively movable, the apparatus comprising:

a laser source carried by the first object for generating a source laser beam toward the second object;

a target optical element carried by the second object for generating a first reflected beam and a second diverging reflected beam from the source laser beam;

a detector carried by the first object for detecting the first reflected beam and the second diverging reflected beam; and

a controller connected to said detector for determining a range between said detector and target optical element based upon a size of the second diverging reflected beam, said controller further defining a first roll angle reference pattern;

said target optical element having a hologram associated therewith for imparting a second roll angle reference pattern to one of the first reflected beam and second diverging reflected beam;

said controller also determining a roll angle based upon the first and second roll angle reference patterns.

27. The apparatus of claim 26 wherein said controller is also for determining at least one other positional degree of freedom quantity based upon the first reflected beam and the second diverging reflected beam.

28. The apparatus of claim 27 wherein said controller determines the at least one other positional degree of freedom quantity by calculating a first centroid for the first reflected beam and a second centroid for the second diverging reflected beam, and determining positions of the first and second centroids.

29. The apparatus of claim 27 wherein said controller defines vertical and lateral reference coordinates;

and wherein the at least one other positional degree of freedom quantity comprises at least one of vertical displacement, lateral displacement, pitch angle, and yaw angle.

30. The apparatus of claim 26 wherein said controller further determines at least one of alignment error data and second object position data based upon the determined range and the determined roll angle.

31. The apparatus of claim 26 wherein said target optical element comprises a lens.

32. The apparatus of claim 26 wherein said target optical element comprises a corner cube.

33. A method for determining relative positioning of first and second objects being relatively movable, the method comprising:

generating a source laser beam toward the second object;

generating a first reflected beam and a second diverging reflected beam from the source laser beam using a target optical element carried by the second object;

detecting the first reflected beam and the second diverging reflected beam using a detector carried by the first object;

determining a range between the detector and target optical element based upon a size of the second diverging reflected beam; and

determining at least one other positional degree of freedom quantity based upon the first reflected beam and the second diverging reflected beam.

34. The method of claim 33 wherein determining the at least one other positional degree of freedom quantity comprises:

calculating a first centroid for the first reflected beam and a second centroid for the second diverging reflected beam; and

determining positions of the first and second centroids.

35. The method of claim 33 wherein the at least one other positional degree of freedom quantity comprises at least one of vertical displacement, lateral displacement, pitch angle, and yaw angle.

36. The method of claim 33 further comprising defining a first roll angle reference pattern;

wherein the target optical element has a pattern generator associated therewith for imparting a second roll angle reference pattern to one of the first reflected beam and second diverging reflected beam; and

wherein determining the at least one other positional degree of freedom quantity comprises determining a roll angle based upon the first and second roll angle reference patterns.

37. The method of claim 36 wherein the pattern generator comprises a diffractive optical element (DOE).

38. The method of claim 33 further comprising determining at least one of alignment error data and second object position data based upon the determined range and the determined at least one other positional degree of freedom quantity.

39. The method of claim 33 wherein the target optical element comprises a lens.

40. The method of claim 39 wherein the lens has a flat rear surface and a convex front surface.

41. The method of claim 33 wherein the target optical element comprises a corner cube.