Nine dimensional laser tracking system and method

• US 20030206285A1
• Filed: 05/06/2003
• Published: 11/06/2003
• Est. Priority Date: 05/06/2002
• Status: Abandoned Application

• Current Assignee: Automated Precision Inc.
• Original Assignee: Automated Precision Inc.
• Inventors: Lau, Kam C.
• Application Number:
  US10/429,680
• Publication Number:
  US 20030206285A1
• Time in Patent Office: Days
• US Class Current: 356/4.09
• CPC Class Codes: B25J 13/089 Determining the position of the robot with reference to its environment
• CPC Class Codes: B25J 9/1692 Calibration of manipulator
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/74 Systems using reradiation of electromagnetic waves other than radio waves, e.g. IFF, i.e. identification of friend or foe
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders

Abstract

A laser based tracking unit communicates with a target to obtain position information about the target. Specifically, the target is placed at the point to be measured. The pitch, yaw and roll of the target, and the spherical coordinates of the target relative to the tracking unit are then obtained. Then additional information regarding a probe attached to the target reconciled with the above determination to determine a position of a probe tip. The target can be, for example, an active device incorporated into a moveable device such a remote controlled robot.

Claims

1. A multidimensional measurement system comprising:

a tracking unit that emits a laser, the tracking unit having a position represented by spherical coordinates;

a target in communication with the tracking unit, the target having a pitch, a yaw and a roll;

a distance determining module that determines a distance between the tracking unit and the target;

a probe removably affixed to the target, the probe comprising a probe tip that is a distance d from a known location on the target; and

an output device that outputs position information about the probe tip relative to the tracking unit based at least on the pitch, yaw, roll, spherical coordinates distance and distance d.

2. The system of claim 1, wherein the probe is adapted to be moved relative to the target.

3. The system of claim 1, wherein the target and the probe are initialized by a point cloud or fixture with a known position comprising a plurality of the distances d.

4. The system of claim 3, wherein the point cloud is a semispherical map of the position of the probe tip relative to the target.

5. The system of claim 1, wherein the probe is extendable in at least one direction.

6. The system of claim 5, wherein the position information about the probe tip relative to the tracking unit is based at least on the pitch, yaw, roll, spherical coordinates, distance, distance d and point cloud information.

7. The system of claim 1, wherein the probe is rotatable in at least one direction, the rotation represented by encoder information.

9. The system of claim 1, further comprising a seat, the seat adapted to cradle the probe tip during initialization.

10. The system of claim 7, wherein the seat is at a known coordinate position relative to the tracking unit.

11. The system of claim 1, further comprising a plurality of probes, each probe having a corresponding point cloud used to determine the distance d.

12. The system of claim 1, wherein the roll is based on at least one of a comparison between a horizontally polarized and a vertically polarized portion of the laser, and measurements from an electronic level.

13. The system of claim 1, further comprising a first photodetector that detects a horizontally polarized portion of the laser and a second photodetector that detects a vertically polarized portion of the laser.

14. The system of claim 13, further comprising a differential amplifier that receives an output of the first photodetector and an output of the second photodetector.

15. The system of claim 1, wherein the target is an active target that is capable of moving relative to the tracking unit.

16. The system of claim 15, wherein the active target is at least one of incorporated into a robotic device, fixably attached to an object, fixably attached to a vehicle, used for feedback control, used for calibration, used for machine tool control, used for parts assembly, and used for structural assembly.

17. The system of claim 16, wherein the robotic device comprises a drive system and one or more traction devices that allow the robotic device to adhere to a surface.

18. The system of claim 17, wherein the robotic device is adapted to be remotely controlled.

19. The system of claim 1, further comprising one or more accessories that perform a function at least based on the position of the probe tip.

20. The system of claim 1, wherein the probe is at least one of L-shaped, J-shaped, V-shaped and curved.

8. The system of claim 8, wherein the position information about the probe tip relative to the tracking unit is based at least on the pitch, yaw, roll, spherical coordinates, distance, distance d, vector information and encoder information.

21. A method of initializing a multidimensional measurement system comprising:

determining a probe type;

monitoring one or more of rotation of probe base and position of probe relative to a target defined by arc ;

placing a probe tip in a known location;

moving the target relative to the known location; and

developing a point cloud representing a distance between the probe tip and a known location on the target.

22. The method of claim 21, further comprising establishing communications between a tracking unit and the target.

23. The method of claim 21, further comprising storing and associating the point cloud with a specific probe type.

24. The method of claim 21, further comprising monitoring one or more encoders that output orientation information about the probe tip.

25. A method of measuring the position of an object comprising:

monitoring spherical coordinates of a laser emitting tracking unit;

monitoring a pitch, a yaw and a roll and of a target in communication with the tracking unit;

monitoring an orientation of a probe tip relative to the target;

determining a distance between the tracking unit and the target;

determining a distance between the probe tip and the target; and

outputting position information about the probe tip relative to the tracking unit.

26. The method of claim 25, wherein the roll is based on at least one of a comparison between a horizontally polarized and a vertically polarized portion of the laser, and en electronic level.

27. The method of claim 26, wherein a differential amplifier performs the comparison between the horizontally polarized and the vertically polarized portion of the laser.

28. The method of claim 25, wherein the target is an active target that is capable of moving relative to the laser.

29. The method of claim 28, wherein the active target is at least one of incorporated into a robotic device, fixably attached to an object, fixably attached to a vehicle, used for feedback control, used for calibration, used for machine tool control, used for parts assembly, and used for structural assembly.

30. The method of claim 25, further comprising performing a function at the target based at least on the position of the probe tip.

31. The method of claim 25, wherein determining a distance between the probe tip and the target is based on correlating at least the distance to a point cloud.

32. The method of claim 25, wherein monitoring an orientation of a probe tip relative to the target comprises monitoring position information obtained from one or more encoders.

33. The method of claim 25, wherein the one or more encoders measure at least one of rotation and extension information about the probe tip relative to the target.

34. A system that initializes a multidimensional measurement system comprising:

means for determining a probe type;

means for monitoring one or more of rotation of probe base and position of probe relative to a target defined by arc ;

means for placing a probe tip in a known location;

means for moving the target relative to the known location; and

means for developing a point cloud representing a distance between the probe tip and a known location on the target.

35. The system of claim 34, further comprising means for establishing communications between a tracking unit and the target.

36. The system of claim 34, further comprising means for storing and associating the point cloud with a specific probe type.

37. The system of claim 34, further comprising means for monitoring one or more encoders that output orientation information about the probe tip.

38. A system that measures the position of an object comprising:

means for monitoring spherical coordinates of a laser emitting tracking unit;

means for monitoring a pitch, a yaw and a roll and of a target in communication with the tracking unit;

means for monitoring an orientation of a probe tip relative to the target;

means for determining a distance between the tracking unit and the target;

means for determining a distance between the probe tip and the target; and

means for outputting position information about the probe tip relative to the tracking unit.

39. The system of claim 38, wherein the roll is based on at least one of a comparison between a horizontally polarized and a vertically polarized portion of the laser, and en electronic level.

40. The system of claim 38, further comprising means for performing the comparison between the horizontally polarized and the vertically polarized portion of the laser.

41. The system of claim 38, wherein the target is an active target that is capable of moving relative to the laser.

42. The system of claim 41, wherein the active target is at least one of incorporated into a robotic device, fixably attached to an object, fixably attached to a vehicle, used for feedback control, used for calibration, used for machine tool control, used for parts assembly, and used for structural assembly.

43. The system of claim 38, further comprising means for performing a function at the target based at least on the position of the probe tip.

44. The system of claim 38, wherein the means for determining a distance between the probe tip and the target is based on a means for correlating at least the distance to a point cloud.

45. The system of claim 38, wherein the means for monitoring an orientation of a probe tip relative to the target comprises means for monitoring position information obtained from one or more encoders.

46. The system of claim 45, wherein the one or more encoders measure at least one of rotation and extension information about the probe tip relative to the target.

47. A probe assembly adapted to measure one or more points comprising:

a target that at least communicates position information about the target to a base station;

a probe comprising a probe tip that is associated with the target, the location of the probe capable of being determined based on a point cloud.

48. The probe of claim 47, further comprising

49. The probe of claim 47, where the probe assembly is capable of continuously taking surface measurements.

50. The probe of claim 47, further comprising a trigger activated measurement system.