Handheld laser light detector with height correction, using a GPS receiver to provide two-dimensional position data

• US 7,409,312 B2
• Filed: 06/29/2007
• Issued: 08/05/2008
• Est. Priority Date: 07/12/2006
• Status: Active Grant

• Current Assignee: Trimble Navigation Limited (Trimble Inc.)
• Original Assignee: Apache Technologies, Inc. (Trimble Inc.)
• Inventors: Conner, Robert G., Zalusky, James T.
• Primary Examiner(s): Bui; Bryan
• Application Number:
  US11/824,459
• Publication Number:
  US 20080015811A1
• Time in Patent Office: 403 Days
• Field of Search: 702/95, 702/97, 702/149, 702/150, 702/159, 332/86, 336/40, 356/248, 356/249
• US Class Current: 702/159
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105
• CPC Class Codes: G01C 15/004 Reference lines, planes or sectors
• 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 light receiver is provided with an integral laser distance measurement (LDM) device for measuring the distance from a laser plane of a desired elevation to a desired physical target point to be measured on a jobsite. The laser receiver can be combined with a gravity reference device, so that the laser receiver does not necessarily have to be held plumb to a desired target point, when determining the relative elevation of the laser receiver between a rotating beam of laser light and the target point; it can also acquire multiple samples of positions and automatically take a vertical measurement and store that result for later readout. The laser receiver can be further combined with a GPS receiver, to acquire latitude and longitude data, and then in combination act as a three-dimensional transducer that is more accurate in the vertical direction than a GPS receiver alone is capable of.

Claims

1. A laser light receiver, comprising:

a housing;

a first laser light photosensor, which generates a first signal if receiving a beam of laser light energy from an external laser light source;

a visible readout to indicate if said laser light receiver is substantially on-grade with respect to said beam of laser light energy;

a visible light marker;

a distance measuring device that uses a second laser light source and a second laser light photosensor, said distance measuring device being used to substantially determine a first distance between said second laser light photosensor and a predetermined external position, as selected by a user of said laser light receiver apparatus while aiming said visible light marker, said second laser light photosensor generating a second signal if receiving reflected laser light energy from said second laser light source;

a level vial; and

a processing circuit that receives said first signal and said second signal;

wherein said housing, said first laser light photosensor, said distance measuring device, said level vial, said visible readout, and said processing circuit are assembled as a unitary hand-held apparatus.

2. The laser light receiver as recited in claim 1, wherein said processing circuit is configured to:

(a) substantially determine a relative location of said laser light receiver with respect to said beam of laser light energy, and if said relative location is on-grade, to output a third signal to said visible readout;

(b) substantially determine a corrected first distance, based upon said second signal and an inherent distance due to component positioning within said housing; and

(c) substantially determine a relative elevation between said predetermined external position and said beam of laser light energy, based upon said corrected first distance if said relative location is substantially on-grade, and if said laser light receiver is substantially level.

3. The laser light receiver as recited in claim 2, wherein said level vial is visually read by said user so as to allow said laser light receiver to be held in an orientation that is substantially level while said processing circuit determines said relative elevation.

4. The laser light receiver as recited in claim 2, further comprising an acoustic output device;

wherein if said relative location is substantially on-grade, said processing circuit is further configured to output a fourth signal causing an audible tone to be generated by said acoustic output device.

5. The laser light receiver as recited in claim 1, wherein said first signal generated by the first laser light photosensor includes sufficient information that allows said processing circuit to substantially determine a second distance between said beam of laser light energy and a current position of said laser light receiver.

6. The laser light receiver as recited in claim 5, wherein said first laser light photosensor comprises one of:

(a) a plurality of photodetector elements that each individually output one of a first plurality of electrical signals if impacted by said beam of laser light energy, in which said first plurality of electrical signals is used by said processing circuit to substantially determine said second distance; and

(b) a rod sensor comprising an elongated light pathway having two ends and two photodetector elements, one of said photodetector elements positioned at each of said two ends of the light pathway, said photodetector elements each individually outputting one of a second plurality of electrical signals, in which said beam of laser light energy impacts said rod sensor at a location along the elongated light pathway, and the second plurality of electrical signals is used by said processing circuit to substantially determine said second distance.

7. The laser light receiver as recited in claim 5, wherein said processing circuit is further configured to:

(a) substantially determine a relative location of said laser light receiver with respect to said beam of laser light energy, and to output a third signal to said visible readout;

(b) substantially determine a corrected first distance, based upon said second signal and an inherent distance due to component positioning within said housing; and

(c) substantially determine said relative elevation between said predetermined external position and said beam of laser light energy, based upon said corrected first distance and said second distance, and if said laser light receiver is substantially level.

8. The laser light receiver as recited in claim 7, wherein said level vial is visually read by said user so as to allow said laser light receiver to be held in an orientation that is substantially level while said processing circuit determines said relative elevation.

9. A laser light receiver, comprising:

a housing;

a first laser light photosensor, which generates a first signal if receiving a beam of laser light energy from an external laser light source;

a visible readout to indicate if said laser light receiver is substantially on-grade with respect to said beam of laser light energy;

a visible light marker;

a distance measuring device that uses a second laser light source and a second laser light photosensor, said distance measuring device being used to substantially determine a first distance between said second laser light photosensor and a predetermined external position, as selected by a user of said laser light receiver apparatus while aiming said visible light marker, said second laser light photosensor generating a second signal if receiving reflected laser light energy from said second laser light source;

a gravity sensor that generates a third signal that is substantially indicative of an angular orientation of said housing with respect to gravity; and

a processing circuit that receives said first signal, said second signal, and said third signal;

wherein said housing, said first laser light photosensor, said distance measuring device, said gravity sensor, said visible readout, and said processing circuit are assembled as a unitary hand-held apparatus.

10. The laser light receiver as recited in claim 9, wherein said processing circuit is configured to:

(a) substantially determine a relative location of said laser light receiver with respect to said beam of laser light energy, and if said relative location is on-grade, to output a fourth signal to said visible readout;

(b) substantially determine a corrected first distance, based upon said second signal, an inherent distance due to component positioning within said housing, and said third signal to compensate for the angular orientation of said housing with respect to gravity; and

(c) substantially determine a relative elevation between said predetermined external position and said beam of laser light energy, based upon said corrected first distance and said second distance, if said relative location is substantially on-grade.

11. A laser light receiver, comprising:

a housing;

a first laser light photosensor, which generates a first signal if receiving a beam of laser light energy from an external laser light source, said first signal being indicative of a second distance between said beam of laser light energy and an on-grade position of said laser light receiver;

a visible light marker;

a distance measuring device that uses a second laser light source and a second laser light photosensor, said distance measuring device being used to substantially determine a first distance between said second laser light photosensor and a predetermined external position, as selected by a user of said laser light receiver apparatus while aiming said visible light marker, said second laser light photosensor generating a second signal if receiving reflected laser light energy from said second laser light source;

a gravity sensor that generates a third signal that is substantially indicative of an angular orientation of said housing with respect to gravity;

a visible readout to indicate a relative elevation; and

a processing circuit that receives said first signal, said second signal, and said third signal;

wherein said housing, said first laser light photosensor, said distance measuring device, said gravity sensor, said visible readout, and said processing circuit are assembled as a unitary hand-held apparatus.

12. The laser light receiver as recited in claim 11, wherein said processing circuit is configured to:

(a) substantially determine said second distance based upon said first signal;

(b) substantially determine a corrected first distance, based upon said second signal, an inherent distance due to component positioning within said housing, and said third signal to compensate for the angular orientation of said housing with respect to gravity;

(c) substantially determine said relative elevation, which is a vertical distance between said predetermined external position and said beam of laser light energy, based upon said corrected first distance and said second distance; and

(d) output a fourth signal to said visible readout so as to display said relative elevation.

13. The laser light receiver as recited in claim 11, wherein said processing circuit is configured to:

(a) substantially determine said second distance based upon said first signal;

(b) substantially determine a corrected first distance, based upon said second signal, an inherent distance due to component positioning within said housing, and said third signal to compensate for the angular orientation of said housing with respect to gravity;

(c) substantially determine said relative elevation, based upon said corrected first distance and said second distance; and

(d) output a fourth signal to said visible readout so as to display said relative elevation;

wherein said relative elevation is displayed in terms of one of;

(e) elevation of said predetermined external position with respect to sea level;

(f) elevation of said housing with respect to sea level;

(g) elevation of said housing with respect to said beam of laser light energy; and

(h) elevation of said housing with respect to said predetermined external position.

14. The laser light receiver as recited in claim 12, further comprising an input control device actuatable by a user that places said laser light receiver into an automatic measurement mode, such that said processing circuit is further configured to substantially determine said relative elevation on a repetitive basis and, if predetermined conditions occur, to store in a memory circuit at least one value of said relative elevation.

15. The laser light receiver as recited in claim 14, wherein said at least one stored value of said relative elevation is displayed on said visible readout.

16. The laser light receiver as recited in claim 14, further comprising an audible output device that generates an audible signal upon the occurrence of said predetermined conditions, and after at least one value of said relative elevation has been stored in said memory circuit.

17. A laser light receiver, comprising:

a housing;

a first laser light photosensor, which generates a first signal if receiving a beam of laser light energy from an external laser light source, said first signal being indicative of a second distance between said beam of laser light energy and an on-grade position of said laser light receiver;

a visible light marker;

a distance measuring device that uses a second laser light source and a second laser light photosensor, said distance measuring device being used to substantially determine a first distance between said second laser light photosensor and a predetermined external position, as selected by a user of said laser light receiver apparatus while aiming said visible light marker, said second laser light photosensor generating a second signal if receiving reflected laser light energy from said second laser light source;

a GPS (global positioning sensor) receiver that generates a third signal that is indicative of a position with respect to the Earth'"'"'s surface;

a tilt indication device;

a visible readout to indicate a relative elevation between said predetermined external position and said beam of laser light energy; and

a processing circuit that receives said first signal, said second signal, and said third signal;

wherein;

(a) said housing, said first laser light photosensor, said distance measuring device, said tilt indication device, said visible readout, said GPS receiver, and said processing circuit are assembled as a unitary hand-held apparatus; and

(b) said processing circuit is configured to;

(i) use said third signal is to substantially determine a position in the horizontal plane with respect to the Earth'"'"'s surface, and (ii) use said first and second signals to substantially determine said relative elevation, based upon said first distance and said second distance.

18. The laser light receiver as recited in claim 17, wherein said relative elevation based on said first and second signals has greater accuracy than an elevation fix based upon said third signal generated by said GPS receiver.

19. The laser light receiver as recited in claim 17, wherein said tilt indication device comprises a level vial.

20. The laser light receiver as recited in claim 17, wherein said tilt indication device comprises a gravity sensor that generates a fourth signal that is substantially indicative of an angular orientation of said housing with respect to gravity, and wherein said processing circuit receives said fourth signal and uses it to compensate for the angular orientation of said housing with respect to gravity.

21. The laser light receiver as recited in claim 17, wherein said visible readout indicates if said laser light receiver is one of:

(a) substantially on-grade with respect to said beam of laser light energy;

(b) above grade with respect to said beam of laser light energy;

and (c) below grade with respect to said beam of laser light energy.

22. The laser light receiver as recited in claim 17, wherein said first laser light photosensor comprises one of:

(a) a plurality of photodetector elements that each individually output one of a first plurality of electrical signals if impacted by said beam of laser light energy, in which said first plurality of electrical signals is used by said processing circuit to substantially determine said second distance; and

(b) a rod sensor comprising an elongated light pathway having two ends and two photodetector elements, one of said photodetector elements positioned at each of said two ends of the light pathway, said photodetector elements each individually outputting one of a second plurality of electrical signals, in which said beam of laser light energy impacts said rod sensor at a location along the elongated light pathway, and the second plurality of electrical signals is used by said processing circuit to substantially determine said second distance.

23. A method for determining an elevation, said method comprising:

providing a laser light receiver having;

a housing, a first laser light photosensor that generates a first signal if receiving a beam of laser light energy from an external laser light source, a visible readout, a visible light marker, a distance measuring device that uses a second laser light source and a second laser light photosensor, a level vial, and a processing circuit;

aiming said visible light marker at a predetermined external position, while holding said housing at a substantially level orientation, as indicated by said level vial;

determining substantially a first distance between said second laser light photosensor and said predetermined external position, by use of said distance measuring device;

determining substantially a second distance of said laser light receiver with respect to said beam of laser light energy; and

determining substantially a relative elevation between said predetermined external position and said beam of laser light energy, based upon said first distance and said second distance.

24. The method as recited in claim 23, further comprising the step of generating an audible tone by an acoustic output device if said housing is on-grade.

25. The method as recited in claim 23, further comprising the step of automatically determining said relative elevation, even if said housing is not on-grade.

26. A method for determining an elevation, said method comprising:

providing a laser light receiver having;

a housing, a first laser light photosensor that generates a first signal if receiving a beam of laser light energy from an external laser light source, a visible readout, a visible light marker, a distance measuring device that uses a second laser light source and a second laser light photosensor, a gravity sensor which generates a tilt-angle signal that is substantially indicative of an angular orientation of said housing with respect to gravity, and a processing circuit;

aiming said visible light marker at a predetermined external position, while holding said housing at a user-desired orientation;

determining substantially a first distance between said second laser light photosensor and said predetermined external position, by use of said distance measuring device;

determining substantially a second distance of said laser light receiver with respect to said beam of laser light energy; and

determining substantially a relative elevation, based upon said first distance and said second distance.

27. The method as recited in claim 26, further comprising the step of automatically determining said relative elevation, even if said housing is not on-grade.

28. The method as recited in claim 26, further comprising the step of automatically determining said relative elevation, even if said housing is not oriented so as to be level, by:

(a) determining substantially a corrected second distance using said tilt-angle signal; and

(b) determining substantially a corrected first distance using said tilt-angle signal, and an inherent distance due to component positioning within said housing.

29. The method as recited in claim 26, further comprising the step of displaying said relative elevation on said visible readout.

30. The method as recited in claim 29, wherein said relative elevation is displayed in terms of a vertical elevation between said beam of laser light energy and said predetermined external position.

31. The method as recited in claim 29, wherein said relative elevation is displayed in terms of one of:

(a) elevation of said predetermined external position with respect to sea level;

(b) elevation of said housing with respect to sea level;

(c) elevation of said housing with respect to said beam of laser light energy; and

(d) elevation of said housing with respect to said predetermined external position.