Self-aligning laser transmitter having a dual slope grade mechanism

• US 5,852,493 A
• Filed: 03/13/1997
• Issued: 12/22/1998
• Est. Priority Date: 03/13/1997
• Status: Expired due to Term

• Current Assignee: Trimble Navigation Limited (Trimble Inc.)
• Original Assignee: Spectra Precision Inc. (Trimble Inc.)
• Inventors: Monnin, Douglas Bernard
• Primary Examiner(s): Hellner, Mark
• Application Number:
  US08/815,623
• Time in Patent Office: 649 Days
• Field of Search: 356/141.1, 356/141.3, 356/141.5, 356/137.1, 356/148, 356/147, 33/291
• US Class Current: 356/141.1
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105

Abstract

A self-aligning laser transmitter having a dual slope grade mechanism is provided. The laser transmitter includes a light source coupled to a frame which is suspended from a gimbal mechanism. The gimbal mechanism and the frame are coupled to a rotatable base. X and Y axes leveling devices are coupled to the gimbal mechanism and the frame to level the light source. A grade arm having two level sensors mounted at ninety degrees to one another is coupled to the frame. The grade arm is pivoted along the X or Y axes by a grade arm pivoting device. The X and Y axes leveling devices reposition the light source so that the level sensors are level thereby introducing a slope to the light source corresponding to the amount of pivot of the grade arm. The base may be rotated for a dual slope capability. The laser transmitter may be self-aligned automatically by aligning the laser transmitter with a target positioned at a reference location. A digital processor may be used to control the rotating device so that the laser transmitter is automatically aligned with the target. The digital processor may control a directional indicator which indicates a direction to rotate the laser transmitter so that the laser transmitter is manually aligned with the target.

Claims

1. An apparatus for projecting laser light in a plane having predetermined slopes with respect to an X-axis and with respect to a Y-axis, said Y-axis being orthogonal to said X-axis, said apparatus comprising:

a housing;

a base rotatably coupled to said housing;

a gimbal mechanism coupled to said base and adapted for pivotal movement about said X-axis;

a frame coupled to said gimbal mechanism and adapted for pivotal movement along said Y-axis;

an optical device coupled to said frame and including a light source to generate said laser light which rotates about a first axis and an optical projecting device to project said laser light in said plane which is orthogonal to said first axis;

an X-axis leveling device coupled to said gimbal mechanism to control an angular orientation of said gimbal mechanism about said X-axis with respect to a Z-axis, said Z-axis being substantially orthogonal to said X and Y axes;

a Y-axis leveling device coupled to said gimbal mechanism and said frame to control an angular orientation of said frame about said Y-axis with respect to said Z-axis;

a grade arm rotatably coupled to said frame and including a first level sensor adapted to sense said angular orientation of said gimbal mechanism and a second level sensor adapted to sense said angular orientation of said frame;

a grade arm pivoting device coupled to said grade arm to control a predetermined angular orientation of said grade arm with respect to one of said X or Y axes;

a rotating device coupled to said base to adjust an angular orientation of said base with respect to a reference axis, said base being rotated about said Z-axis; and

a processor programmed to set said predetermined angular orientation of said grade arm and said angular orientation of said base based on said predetermined slopes, said processor adapted to control said X-axis leveling device and said Y-axis leveling device so that said first and second level sensors are substantially level and said plane of light has said predetermined slopes.

2. The apparatus of claim 1, wherein said grade arm is substantially straight.

3. The apparatus of claim 2, wherein said base includes a position measuring device to measure said angular orientation of said base with respect to said reference axis.

4. The apparatus of claim 3, wherein said position measuring device is a rotary encoder.

5. The apparatus of claim 1, further comprising a reflective target that is positioned at a desired location from said apparatus, wherein said optical device includes a photodetecting system to detect said laser light reflected from said reflective target and generate a signal representative of said location, said processor adapted to receive said signal and to control said rotating device so that said reference axis is substantially parallel with a line defined by said apparatus and said target.

6. The apparatus of claim 5, wherein said predetermined slopes are inputted by a user into the processor.

7. The apparatus of claim 5, wherein said photodetecting system includes an optical encoder.

8. The apparatus of claim 5, wherein said reflective target comprises a retroreflector.

9. The apparatus of claim 3, wherein said predetermined slopes are inputted by a user into said processor.

10. The apparatus of claim 1, wherein said base includes a first gearing mechanism, said rotating device includes a second gearing mechanism in engagement with said first gearing mechanism and a motor coupled to said second gearing mechanism.

11. The apparatus of claim 1, wherein said grade arm pivoting device includes a leadscrew nut coupled to said grade arm, a leadscrew threadly engaged with said leadscrew nut, and a motor coupled to said leadscrew.

12. The apparatus of claim 1, wherein a range of rotation of said grade arm is about ±

45 degrees.

13. An apparatus for projecting laser light in a plane having predetermined slopes with respect to an X-axis and with respect to a Y-axis, said Y-axis being substantially orthogonal to said X-axis, said apparatus comprising:

a base;

a gimbal mechanism coupled to said base and adapted for pivotal movement about said X-axis;

a frame coupled to said gimbal mechanism and adapted for pivotal movement along said Y-axis;

an optical device coupled to said frame and including a light source to generate said laser light which rotates about a first axis, an optical projecting device to project said laser light in said plane which is orthogonal to said first axis, and a photodetecting system;

an X-axis leveling device coupled to said gimbal mechanism to control an angular orientation of said gimbal mechanism about said X-axis with respect to a Z-axis, said Z-axis being substantially orthogonal to said X and Y axes;

a Y-axis leveling device coupled to said gimbal mechanism and said frame to control an angular orientation of said frame about said Y-axis with respect to said Z-axis;

a grade arm rotatably coupled to said frame and including a first level sensor adapted to sense said angular orientation of said gimbal mechanism and a second level sensor adapted to sense said angular orientation of said frame;

a grade arm pivoting device coupled to said grade arm to control a predetermined angular orientation of said grade arm with respect to one of said X or Y axes;

a reflective target that is positioned at a desired location from said apparatus;

a directional indicator; and

a processor;

wherein said photodetecting system detects reflected laser light from said reflective target and generates a signal representative of said location, said processor is adapted to receive said signal and programmed to set said predetermined angular orientation of said grade arm and to control said directional indicator to indicate a direction to rotate said base about said Z-axis so that said plane of light has said predetermined slopes.

14. The apparatus of claim 13, wherein said directional indicator indicates a direction to rotate said base based on said signal so that a reference axis is substantially parallel with a line defined by said apparatus and said target.

15. The apparatus of claim 14, wherein said processor is adapted to control said directional indicator to indicate a direction to rotate said base with respect to said reference axis so that said plane of light has said predetermined slopes.

16. The apparatus of claim 13, wherein said grade arm is substantially straight.

17. The apparatus of claim 13, wherein said predetermined slopes are inputted by a user into the processor.

18. The apparatus of claim 13, wherein said photodetecting system includes an optical encoder.

19. The apparatus of claim 13, wherein said reflective target comprises a retroreflector.

20. The apparatus of claim 13, wherein said grade arm pivoting device includes a leadscrew nut coupled to said grade arm, a leadscrew threadly engaged with said leadscrew nut, and a motor coupled to said leadscrew.

21. The apparatus of claim 13, wherein a range of rotation of said grade arm is about ±

45 degrees.

22. An automated process for projecting laser light in a plane having predetermined slopes with respect to an X-axis and with respect to a Y-axis, said Y axis being orthogonal to said X-axis, said process comprising the steps of:

projecting said laser light from a light source along a first axis;

directing said laser light along said plane which is orthogonal to said first axis;

positioning said light source at a first angle with respect to one of said X and Y axes;

rotating said light source a set number of degrees about a Z-axis with respect to a reference axis, said Z-axis being substantially orthogonal to said X and Y axes; and

calculating said first angle and said set number of degrees based on said predetermined slopes using a digital processor.

23. The process of claim 22, wherein said predetermined slopes are inputted by a user into said digital processor.

24. The process of claim 22, wherein said step of rotating said light source includes rotating a base with respect to a housing, said housing being coupled to said base, said base being coupled to a gimbal mechanism which is adapted for pivotal movement about said X-axis, said gimbal mechanism being coupled to a frame which is adapted for pivotal movement about said Y-axis, and said light source being coupled to said frame.

25. The process of claim 24, wherein said step of rotating said light source includes using a rotary encoder to measure said set number of degrees from said reference axis.

26. The process of claim 24, wherein said step of positioning said light source includes tilting a grade arm which is rotatably coupled to said light source to said first angle, said grade arm including a first level sensor adapted to sense an angular orientation of said light source about said X-axis with respect to said Z-axis and a second level sensor adapted to sense an angular orientation of said light source about said Y-axis with respect to said Z-axis, said position of said light source being adjusted so that said first and second level sensors are substantially level and said plane of light has said predetermined slopes.

27. The process of claim 26, wherein said grade arm is substantially straight.

28. A process for projecting laser light in a plane having predetermined slopes with respect to an X-axis and with respect to a Y-axis, said Y-axis being orthogonal to said X-axis, said process comprising the steps of:

projecting said laser light from a light source along a first axis;

directing said laser light along said plane which is orthogonal to said first axis;

positioning a reflective target at a desired location;

detecting laser light reflected from said reflective target and generating a signal representative of said location; and

positioning said light source so that said plane of light has said predetermined slopes.

29. The process of claim 28, wherein said step of positioning said light source includes rotating said light source based on said signal so that a reference axis is substantially parallel with a line defined by said light source and said target.

30. The process of claim 29, wherein said step of positioning said light source includes positioning said light source at a first angle with respect to one of said X and Y axes.

31. The process of claim 30, wherein said step of positioning said light source at said first angle with respect to one of said X and Y axes includes tilting a grade arm which is rotatably coupled to said light source at said first angle, said grade arm including a first level sensor adapted to sense an angular orientation of said light source about said X-axis with respect to a Z-axis and a second level sensor adapted to sense an angular orientation of said light source about said Y-axis with respect to said Z-axis, said Z-axis being substantially orthogonal to said X and Y axes, said position of said light source is adjusted so that said first and second level sensors are substantially level and said plane of light has said predetermined slopes.

32. The process of claim 30, wherein said step of positioning said light source includes rotating a base a set number of degrees about said Z-axis with respect to said reference axis, said base being coupled to a gimbal mechanism which is adapted for pivotal movement about said X-axis, said gimbal mechanism being coupled to a frame which is adapted for pivotal movement about said Y-axis, and said light source being coupled to said frame.

33. The process of claim 31, wherein said grade arm is substantially straight.

34. A process for projecting laser light in a plane having predetermined slopes with respect to an X-axis and with respect to a Y-axis, said Y-axis being orthogonal to said X-axis, said process comprising the steps of:

projecting said laser light from a light source along a first axis;

directing said laser light along said plane which is orthogonal to said first axis;

positioning a reflective target at a desired location;

detecting laser light reflected from said reflective target and generating a signal representative of said location;

positioning said light source at a first angle with respect to one of said X and Y axes;

indicating a direction to rotate said light source, said light source being rotated about a Z-axis, said Z-axis being substantially orthogonal to said X and Y axes; and

calculating said first angle and said direction so that said plane of laser light has said predetermined slopes.

35. The process of claim 34, wherein said step of indicating a direction to rotate said light source includes indicating a direction to rotate said light source based on said signal so that a reference axis is substantially parallel with a line defined by said apparatus and said target.

36. The process of claim 35, wherein said step of indicating a direction to rotate said light source includes indicating a direction to rotate said light source with respect to said reference axis so that said plane of light has said predetermined slopes.

37. The process of claim 36, wherein said step of indicating a direction to rotate said light source includes rotating a base, said base being coupled to a gimbal mechanism which is adapted for pivotal movement about said X-axis, said gimbal mechanism being coupled to a frame which is adapted for pivotal movement about said Y-axis, and said light source being coupled to said frame.

38. The process of claim 36, wherein said step of positioning said light source includes tilting a grade arm which is rotatably coupled to said light source at said first angle, said grade arm including a first level sensor adapted to sense an angular orientation of said light source about said X-axis with respect to said Z-axis and a second level sensor adapted to sense an angular orientation of said light source about said Y-axis with respect to said Z-axis, said position of said light source being adjusted so that said first and second level sensors are substantially level and said plane of light has said predetermined slopes.

39. The process of claim 38, wherein said grade arm is substantially straight.