Multi-dimensional measuring system with measuring instrument having 360° angular working range

• US 20100149525A1
• Filed: 12/09/2009
• Published: 06/17/2010
• Est. Priority Date: 12/11/2008
• Status: Active Grant

• Current Assignee: Automated Precision Inc.
• Original Assignee: Automated Precision Inc.
• Inventors: Lau, Kam C.
• Granted Patent: US 9,739,595 B2
• Time in Patent Office: Days
• US Class Current: 356/139.30
• CPC Class Codes: G01B 11/002 for measuring two or more coordinates
• CPC Class Codes: G01B 5/012 Contact-making feeler heads therefor
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46

Abstract

A multi-dimensional measuring system is disclosed wherein a laser-based tracking unit communicates with an optical target on a measurement instrument to obtain position and orientation information about the instrument. The optical target incorporates a plurality of encoders configured to provide a full 360° working range in pitch, yaw and roll. Full working range in pitch and yaw is achieved through the use of a pitch/yaw angular encoder. Full 360° working range in roll is achieved with a combination of a level sensor and a 360° angular encoder, which are fixed to a pendulum so that the level sensor is always aligned to gravity. Use of a slip-ring mechanism ensures the unlimited full working range in roll. The measurement instrument includes a scanner integrated with a probe receptacle adapted to accept a probe assembly to provide the instrument with both a scanning measurement and a probe measurement capabilities. Incorporation of an additional probe receptacle provides increased measurement capability and flexibility. The optical target with its full 360° angular working range in pitch, yaw and roll can be utilized independently of the measurement instrument. In combination with a laser tracker, the optical target can be attached to any object or surface to be measured, or alternatively, it can be attached to a movable device and the position of that device monitored.

Claims

1. A measurement device associated with a multi-dimensional tracking system having a source of laser light, comprising:

an optical target in communication with the laser light source, the optical target being capable of motion about orthogonal pitch, yaw and roll axes; and

a plurality of sensors associated with the pitch, yaw and roll axes of movement of said optical target and adapted to provide output indicating the position of said optical target, said optical target being capable of full 360°

of motion about each of said axes of movement.

2. The measurement device of claim 1, wherein said plurality of sensors comprise angular measurement sensors.

3. The measurement device of claim 2, wherein:

said optical target includes a reflector having an aperture disposed therein to permit a portion of laser light incident on the reflector to pass through the reflector; and

a laser light sensor disposed behind the aperture to receive the portion of laser light and provide output indicative of the pitch and yaw positions of said optical target.

4. The measurement device of claim 3, further comprising a pitch and yaw expansion encoder disposed substantially parallel to the pitch axis of movement.

5. The measurement device of claim 3, wherein the sensor associated with movement about the roll axis includes a level sensor and an angular sensor.

6. The measurement device of claim 5, wherein said level sensor and said angular sensor are coupled to a pendulum so that the primary sensitive direction of said level sensor is always aligned to gravity.

7. The measurement device of claim 6 wherein said pendulum comprises a two-dimensional pendulum.

8. The measurement device of claim 5 or 6, wherein said angular sensor comprises an angular encoder.

9. The measurement device of claim 5 or 6, further comprising a rotary support means supporting said level sensor and said angular sensor to provide full, unlimited 360°

working range in movement about the roll axis.

10. The measurement device of claim 9, wherein said rotary support means comprises a slip-ring mechanism.

11. The measurement device of claim 6, wherein said level sensor includes a second pendulum to level the non-measuring axis of said level sensor.

13. The measurement device of any of claims 3 to 7, wherein said reflector comprises a retro-reflector.

12. The measurement device of 11, wherein said second pendulum is rotatably supported on an axis parallel to the pitch axis so that said second pendulum remains aligned with gravity as the measurement device moves in pitch.

14. The measurement device of 13, wherein said retro-reflector comprises a solid retro-reflector having a flat polished surface that defines the aperture.

15. A sensor assembly for measuring the orientation of an object in a multi-dimensional tracking system having a source of laser light, comprising:

an optical target in communication with the laser light source and movable about orthogonal pitch, yaw and roll axes;

an angular sensor assembly coupled to the optical target for measuring 360°

of motion of said optical target about the pitch and yaw axes; and

a roll sensor module coupled to the optical target for measuring 360°

of motion of said optical target about the roll axis.

16. The sensor assembly of claim 15, wherein:

the optical target includes a reflector having an aperture disposed therein to permit passage of a portion of laser light incident on the reflector;

a laser light sensor disposed behind the aperture to receive said portion of laser light and operative to provide outputs in determining the orientation of the sensor assembly relative to the pitch and yaw axes; and

an angle detection sensor disposed substantially parallel to the pitch axis and operative with said laser light sensor to expand the pitch and yaw angular working range of the sensor assembly to full 360°

of motion.

17. The sensor assembly of claim 15 or 16, wherein said roll sensor module comprises a roll angle sensor and a roll level sensor, both coupled to a two-dimensional pendulum such that the roll level sensor is always aligned to gravity.

18. The sensor assembly of claim 17, wherein said two-dimensional pendulum is supported for rotation about the roll axis and rotation about the pitch axis.

19. The sensor assembly of claim 17, further comprising a rotary support member supporting said roll angle sensor and said roll level sensor to provide the sensor assembly full 360°

of motion about the roll axis.

20. The sensor assembly of claim 16, wherein said reflector comprises a retro-reflector.

21. The sensor assembly of claim 20, wherein said retro-reflector comprises a solid retro-reflector having a flat polished surface that defines the aperture.

22. A remote unit associated with a multi-dimensional tracking system having a tracking unit and a laser light source, comprising:

a target in communication with the tracking unit, the target being capable of movement about orthogonal pitch, yaw and roll axes; and

a measuring assembly coupled to the target and operative to make measurements with a scanner device or with a probe-type device.

23. The remote unit of claim 22, wherein said target comprises:

a reflector in communication with the laser light source; and

a plurality of angular sensors associated with the pitch, yaw and roll axes of movement of said reflector, said reflector being capable of full 360°

of motion about each of said axes of movement.

24. The remote unit of claim 22, wherein said target comprises:

a reflector in communication with the laser light source and having an aperture disposed therein to pass through a portion of laser light incident on the reflector; and

a laser light sensor disposed behind the aperture to receive the portion of laser light and provide output indicative of the pitch and yaw position of the measurement device.

25. The remote unit of claim 23, wherein the angular sensors associated with movement about the roll axis includes a level sensor and an angular sensor coupled to a pendulum such that the primary sensitive direction of said level sensor is always aligned to gravity.

26. The remote unit of claim 25, wherein said pendulum comprises a two-dimensional pendulum.

27. The remote unit of claim 25, wherein said level sensor includes a second pendulum to level the non-measuring axis of said level sensor.

29. The remote unit of any of claims 25 to 28, further comprising a rotary support means interconnecting and supporting said level sensor and said angular sensor to provide full, unlimited 360°

working range in movement about the roll axis.

30. The remote unit of any of claims 22 to 28, wherein said measuring assembly comprises:

a support member rotatably coupled to said target;

an optical scanner assembly disposed on said support member;

a first receptacle means adapted to removably mount a probe-type device; and

control means to control activation of the measuring assembly.

31. The remote unit of claim 30, wherein said optical scanner assembly comprises:

a scanner laser disposed within a housing on said support member; and

laser light receiving means for receiving laser light reflected from a measured object.

32. The remote unit of claim 31, wherein said first receptacle means forms part of said housing for said scanner laser.

33. The remote unit of claim 30, wherein said control means comprises a trigger configured to effect one or more measurements associated with a location touched by the probe-type device.

34. The remote unit of claim 30, further comprising a second receptacle means adapted to removably mount a probe-type device, whereby a probe-type device may be mounted in said first receptacle means or in the second receptacle means.

35. The remote unit of claim 31, wherein said scanner laser housing includes means to turn off the scanner laser upon mounting of a probe-type device in said first receptacle means.

36. The remote unit of claim 34, further comprising means on said first and said second receptacle means adapted to obtain information on said probe-type device used to calibrate the remote unit for the installed probe-type device.

37. The remote unit of claim 31, further comprising an optical guide means disposed on said support member and adapted to provide an indication of the optimum separation distance between the remote unit and the measured object.

38. The remote unit of claim 36, wherein said optical guide means comprises a light source and a lens positioned adjacent to the light source to focus the light toward the measured object.

39. The remote unit of claim 37, wherein said optical guide means is disposed at an upwardly-inclined angle relative to the longitudinal axis of said support member.

28. The remote unit of 27, wherein said second pendulum is rotatably supported on an axis oriented parallel to the pitch axis so that said second pendulum remains aligned with gravity as the remote unit moves in pitch.

40. A measurement instrument having integrated probe-type measuring capability and scanning measuring capability comprising:

a support structure;

a scanning means on said support structure;

first receptive means on said support structure for removably mounting a contact-type measuring probe; and

activation means for selectively making measurement with said scanning means or said measuring probe.

41. The measurement instrument of claim 40, wherein said scanning means comprises:

a scanning light source disposed at a first position on said support structure; and

a light receiving means for receiving the light from said scanning light source reflected from the object being measured.

42. The measurement instrument of claim 41, wherein said scanning light source comprises a laser light source disposed within a compartment provided at said first position.

43. The measurement instrument of claim 41 or 42, wherein said light receiving means comprises a camera.

44. The measurement instrument of claim 40, wherein said first receptive means is disposed adjacent to said scanning means.

45. The measurement instrument of claim 42, wherein said first receptive means is disposed on said compartment for said laser light source.

46. The measurement instrument of any of claims 40 to 42, further comprising a second receptive means on said support structure and adapted to removably mount a contact-type measuring probe, said second receptive means located at a position different from said first receptive means.

47. The measurement instrument of any of claims 40 to 42, further comprising an optical guide means disposed on said support structure and adapted to provide an indication of the optimum separation distance between the remote unit and the measured object.

48. The measurement instrument of claim 47, further comprising a second receptive means on said support structure and adapted to removably mount a contact-type measuring probe, said second receptive means located at a position different from said first receptive means.

49. The measurement instrument of claim 46, further comprising means on said first and said second receptive means adapted to obtain information on said contact-type measuring probe used to calibrate the instrument for the installed probe.

50. The measurement instrument of claim 45, wherein said compartment includes means to turn off the scanning means upon mounting of a measuring probe in said first receptive means.

51. A method for making measurements in a multi-dimensional measuring system having a tracker with a source of laser light, a control unit and a target coupled to a measuring device, comprising:

establishing communication between the target and the tracker;

selecting the desired mode of making the measurement on the measuring device having integrated capability of measuring with a scanner or with a contact-type probe;

activating the scanner laser and scanner camera when the scanner mode is selected;

initialize the measuring device in the scanner mode;

directing the scanner laser toward the object being measured;

making measurement with the device in the scanner mode by activating a control mechanism on the device; and

providing measurement data to the control unit.

52. The method of claim 51, further including:

activating an optical guide on the device; and

using the optical guide during measurement to position the device at an optimal distance from the object.

53. The method of claim 51 or 52, wherein:

the step of selecting the desired mode of making the measurement includes selecting a contact-type probe of a first configuration;

mounting the probe in a first position on the device;

initializing the device with the probe in the first position;

inactivating the scanner laser and the scanner camera; and

making measurement with the device in the scanner mode by activating the control mechanism on the device.

54. The method of claim 53, wherein the step of mounting the probe includes the step of mounting the probe in a second position on the device.

55. The method of claim 54, further including:

selecting a second contact-type probe;

mounting the second probe in the second position on the device;

initializing the device with the second probe in the second position; and

making measurement with the device my contacting the object with either the first or the second probe.

56. The method of claim 54, wherein the step of inactivating the scanner laser and the scanner camera is achieved by the mounting of the probe in either the first or the second position.

57. The method of claim 53, further identifying the probe to the control unit prior to initializing the device.

58. The method of claim 57, wherein identification of the probe is achieved upon mounting of the probe and probe-identifying data on the probe is read by the device.

59. The method of claim 55, further identifying the second probe to the control unit prior to initializing the device.

60. The method of claim 59, wherein identification of the second probe is achieved upon mounting of the probe and probe-identifying data on the probe is read by the device.