3D imaging using a laser projector

• US 5,661,667 A
• Filed: 01/04/1995
• Issued: 08/26/1997
• Est. Priority Date: 03/14/1994
• Status: Expired due to Term

• Current Assignee: Virtek Laser Systems Incorporated
• Original Assignee: Virtek Vision Corp. (Gerber Scientific LLC)
• Inventors: Wieczorek, John, Bordignon, Richard Michael, Wigg, David J., Rueb, Kurt D.
• Primary Examiner(s): Voeltz, Emanuel T.
• Assistant Examiner(s): Shah, Kamini S.
• Application Number:
  US08/368,528
• Time in Patent Office: 965 Days
• Field of Search: 359/202, 359/201, 359/221, 358/285, 364/475, 364/559, 364/560, 348/202, 348/203, 348/207, 356/375, 356/372
• US Class Current: 702/95
• CPC Class Codes: G01B 11/002 for measuring two or more coordinates
• CPC Class Codes: G06K 7/10831 Arrangement of optical elements, e.g. lenses, mirrors, prisms optical elements per se G02B

Abstract

A method for generating 3D data of an object using a laser projector uses the steps of calibrating at least two laser projectors to a known coordinate system relative to an object; projecting a first laser beam along a path to a point on the object; placing a reflection target at the point for reflecting the first laser beam for generating a first feedback signal indicative of the first laser beam hitting the reflective target; calculating first vector coordinates of the path of the first laser beam; projecting a second laser beam towards the point; moving the second laser beam in a predetermined pattern until the second laser beam reflects off of the reflective target generating a second feedback signal indicative of the second laser beam hitting the reflective target; calculating second vector coordinates of the path of the second laser beam; triangulating the first vector coordinates with the second vector coordinates establishing a digitized 3D coordinate of the point relative to the coordinate system; responsive to an external signal, storing the 3D coordinate in an electronic memory storage device; manipulating the target reflector to points of interest on the surface; and repeating the steps to generate a series of digitized 3D coordinates.

Claims

1. A method for generating 3D data of an object using a laser projector comprising the steps of:

establishing a coordinate system by selecting at least four non-redundant reference targets on an object,

calibrating at least two laser projectors to said coordinate system by using each of said laser projectors to locate said at least four non-redundant reference targets and calculating a relative 3-dimensional orientation and position of each of said laser projectors relative to said coordinate system,

projecting at least two laser beams along respective paths to a desired point on said object;

calculating vector coordinates for each respective path of said laser beams when each of said laser beams intersects said point; and

triangulating said vector coordinates establishing a digitized 3D coordinate of said point relative to said coordinate system.

2. A method as claimed in claim 1 wherein said method further includes a step of generating a feedback signal when each of said laser beams intersect said point and said step of calculating said vector coordinates is responsive to each of said feedback signals.

3. A method as claimed in claim 2 wherein said method further includes a step of reflecting said lasers beams off said point for triggering each of said feedback signals.

4. A method as claimed in claim 3 wherein said method includes a step of refracting said laser beams towards a light sensor which is responsive to said laser beams for generating said feedback signals.

5. A method as claimed in claim 4 wherein said steps of projecting said laser beams includes a step of focusing each of said lasers beams through an aperture of a wedge-shaped lens adapted to refract said laser beams towards said light sensor.

6. A method as claimed in claim 3 wherein said step of generating said feedback signals includes a step of manipulating a target reflector to said point for reflecting said laser beams.

7. A method as claimed in claim 6 wherein said step of projecting said laser beams includes a step of moving each of said laser beams in a predetermined pattern until each of said laser beams reflects off said reflective target.

8. A method as claimed in claim 7 wherein said step of moving said laser beams commences after a predetermined amount of time.

9. A method as claimed in claim 8 wherein said predetermined pattern is an expanding spiral.

10. A method as claimed in claim 7 wherein each of said laser beams are refracted towards a light sensor for generating said feedback signals.

11. A method as claimed in claim 10 wherein said step of projecting said laser beams includes generating each of said laser beams with a laser light source, focusing each of said laser beams through an aperture of a wedged-shape lens, directing said laser beams towards said point and said step of generating said feedback signals includes reflecting said laser beams off said point back towards said laser light source, refracting said laser beams with said wedged-shape lens towards said light sensor.

12. A method as claimed in claim 11 wherein a reflective target is manipulated to said point to reflect each of said laser beams.

13. A method as claimed in claim 12 wherein said calibration step includes a step of projecting said a laser beam from each of said laser projectors to a plurality of known locations on said object, calculating vector coordinates of each of said known locations and triangulating said vector coordinates establishing a relative 3D orientation and position of each said known locations relative to said object.

14. A method as claimed in claim 13 wherein said steps of triangulating vector coordinates is a closed-form inverse perspective transformation.

15. A method as claimed in claim 1 wherein said method includes a step of storing said 3D coordinate in an electronic memory storage device.

16. A method as claimed in claim 15 wherein said 3D coordinate is stored responsive to an external signal.

17. A method as chimed in claim 16 wherein said external signal is a generated by a computer mouse.

18. A method as claimed in claim 16 wherein said external signal is remotely generated and transmitted to a receiver electrically connected to said electronic memory storage device.

19. A method as claimed in claim 16 wherein said method is repeated for a plurality of points to generate a series of digitized 3D coordinates.

20. A method as claimed in claim 19 wherein said method includes the step of periodically re-calibrating the at least two laser projectors.

21. A method as claimed in claim 19 wherein said method further includes a step of generating an image representative of said series of digitized 3D coordinates and laser projecting said image onto said object.

22. A method as claimed in claim 1 wherein said method further includes a step of terminating a feedback signal when each of said laser beams intersect said point and said step of calculating said vector coordinates is responsive to the termination of each of said feedback signals.

23. A method as claimed in claim 22 wherein said method is switchable from terminating said feedback signal to a step of generating a feedback signal when each of said laser beams intersect said point and said step of calculating said vector coordinates is responsive to each of said feedback signals.

24. A method as claimed in claim 23 wherein said method includes a step of refracting said laser beams towards a light sensor which is responsive to said laser beams for generating said feedback signals.

25. A method as claimed in claim 24 wherein said steps of projecting said laser beams includes a step of focusing each of said lasers beams through an aperture of a wedge-shaped lens adapted to refract said laser beams towards said light sensor after each of said laser beams is reflected.

26. A method as claimed in claim 25 wherein said step of terminating said feedback signals includes a step of manipulating a target reflector having a non-reflecting center to said point.

27. A method as claimed in claim 26 wherein said step of generating said feedback signals includes a step of manipulating a target reflector to said point for reflecting said laser beams.

28. A method as claimed in claim 27 wherein said step of projecting said laser beams includes a step of moving each of said laser beams in a predetermined pattern until each of said laser beams reflects off said reflective target.

29. A method as claimed in claim 28 wherein said predetermined pattern is a circle.

30. A method as claimed in claim 1 wherein said method further includes a step of providing a platform having retroreflectors in a predefined pattern defining a reference coordinate system and said object is placed on said platform for generating 3D data thereof.

31. A method as claimed in claim 30 wherein said method includes the step of calibrating said at least two laser projectors to the reference coordinate system.

43. A method as claimed in claim 1 wherein said step of calibrating includes calibrating said two laser projectors to a reference platform and then calibrating said object to said reference platform.

44. A method as claimed in claim 43 wherein said reference platform is sized to receive said object and said object rests on said platform when undergoing said calibrating.

45. A method as claimed in claim 44 wherein said platform has a plurality of retroreflective targets at predetermined locations thereabout.

46. A method as claimed in claim 45 wherein at least four of said plurality of retroreflective targets reflect said laser beam when said objects rests thereon.

32. A method for generating 3D data of an object using at least two laser projectors comprising the steps of:

establishing a coordinate system by selecting at least four non-redundant reference targets on an object,

calibrating at least two laser projectors to said coordinate system by using each of said laser projectors to locate said at least four non-redundant reference targets and calculating a relative 3-dimensional orientation and position of each of said laser projectors relative to said coordinate system,

generating a first laser beam with a first laser light source, focusing said first laser beam through an aperture of a first wedged-shape lens,

directing said first laser beam towards a point on said object,

reflecting said first laser beam off a reflective target manipulated to said point back towards said first laser light source,

refracting said first laser beam with said first wedged-shape lens towards a first light sensor generating a first feedback signal,

responsive to said first feedback signal, calculating first vector coordinates of said first laser beam;

generating a second laser beam with a second laser light source, focusing said second laser beam through an aperture of a second wedged-shape lens,

directing said second laser beam towards said point,

reflecting said second laser beam off said reflective target back towards said second laser light source,

refracting said second laser beam with said second wedged-shape lens towards a second light sensor generating a second feedback signal,

responsive to said second feedback signal, calculating second vector coordinates of said second laser beam;

triangulating said first vector coordinates with said second vector coordinates establishing a digitized 3D coordinate of said point relative to said coordinate system.

33. A method as claimed in claim 32 wherein said method further includes a step of storing said 3D coordinate in an electronic memory storage device.

34. A method as claimed in claim 33 wherein said method is repeated for a plurality of points to generate a series of digitized 3D coordinates.

35. A method as claimed in claim 34 wherein said method includes the step of periodically calibrating the at least two laser projectors.

36. A method as claimed in claim 35 wherein said method further includes a step of generating an image representative of said series of digitized 3D coordinates and periodically laser projecting said image onto said object.

37. A method for generating 3D data of an object using at least two laser projectors comprising the steps of:

calibrating at least two laser projectors to a coordinate system relative to an object;

generating a first laser beam with a first laser light source, focusing said first laser beam through an aperture of a first wedged-shape lens,

directing said first laser beam towards a point on said object,

reflecting said first laser beam off a reflective target manipulated to said point back towards said first laser light source,

refracting said first laser beam with said first wedged-shape lens towards a first light sensor generating a first feedback signal,

responsive to said first feedback signal, calculating first vector coordinates of said first laser beam;

generating a second laser beam with a second laser light source, focusing said second laser beam through an aperture of a second wedged-shape lens,

directing said second laser beam towards said point,

reflecting said second laser beam off said reflective target back towards said second laser light source,

refracting said second laser beam with said second wedged-shape lens towards a second light sensor generating a second feedback signal,

responsive to said second feedback signal, calculating second vector coordinates of said second laser beam;

triangulating said first vector coordinates with said second vector coordinates establishing a digitized 3D coordinate of said point relative to said coordinate system;

storing said 3D coordinate in an electronic memory storage device;

repeating said method for a plurality of points to generate a series of digitized 3D coordinates;

periodically calibrating the at least two laser projectors;

generating an image representative of said series of digitized 3D coordinates and periodically laser projecting said image onto said object; and

projecting only a portion of said image near a point of interest, responsive to a feedback signal being received from the point of interest.

38. A method as claimed in claim 37 wherein said method further includes a step of manipulating a target reflector to said point of interest.

39. A method as claimed in claim 38 wherein said image includes additional text information and said method further includes a step of projecting a symbol indicative of a presence of said text information and projecting said text information responsive to a feedback signal.

40. A method as claimed in claim 39 wherein said method further includes a step of manipulating a target reflector to said symbol.

41. A method as claimed in claim 40 wherein said calibration steps includes a step of projecting said laser beams from each of said laser projectors to a plurality of known locations on said object, calculating vector coordinates of each of said known locations and triangulating said vector coordinates establishing a relative 3D orientation and position of each said known locations relative to said object.

42. A method as claimed in claim 41 wherein said steps of triangulating vector coordinates is a closed-form inverse perspective transformation.