Method for operating a laser distance measuring device

Patent metadata

Field	Value
Publication number	US-11448768-B2
Application number	US-201816635864-A
Country	US
Kind code	B2
Filing date	Aug 21, 2018
Priority date	Sep 7, 2017
Publication date	Sep 20, 2022
Grant date	Sep 20, 2022

Abstract

The proposed method for operating a laser distance measuring device, in particular a hand-held laser distance measuring device, is based on a method in which laser radiation is emitted to a target point by means of an emitter unit, laser radiation reflected back from the target point is detected by a receiver unit with a detection surface, at least one image of at least one target environment of the target point is captured by at least one camera, and a representation of the image, overlaid with a marking of the target point, is displayed on a screen of the laser distance measuring device. According to the disclosure, a parallax error in the representation of the image, overlaid with a marking of the target point, is corrected according to an estimated distance to the target point. The disclosure also relates to a corresponding laser distance measuring device.

First claim

The invention claimed is:

1. A method for operating a laser distance measurement device, the method comprising:
emitting laser radiation to a target point using a laser;
acquiring reflected laser radiation from the target point using a receiver having a detection surface;
acquiring, with at least one camera, at least one image of at least one target environment of the target point;
outputting a display of the at least one image overlaid with a marker of the target point on a screen of the laser distance measurement device;
determining an estimated distance to the target point based on a light spot brought about by the reflected laser radiation on the detection surface; and
correcting a parallax error in the display of the at least one image overlaid with the marker of the target point based on the estimated distance.

2. The method as claimed in claim 1 further comprising:
determining the estimated distance based on a position of the light spot brought about by the reflected laser radiation on the detection surface.

3. The method as claimed in claim 1 further comprising:
determining the estimated distance based on a size of the light spot brought about by the reflected laser radiation on the detection surface.

4. The method as claimed in claim 3 further comprising:
determining the size of the light spot based on a surface area covered by the light spot on the detection surface.

5. The method as claimed in claim 3 further comprising:
determining the size of the light spot based on a length of a section of a surface area covered by the light spot on the detection surface.

6. The method as claimed in claim 5 the determining the size of the light spot further comprising:
determining the size of the light spot based on a number of illuminated pixels of a pixel row of the detection surface that lies substantially in a parallax plane.

7. The method as claimed in claim 6 , wherein the pixel row of the detection surface that lies substantially in the parallax plane runs substantially collinear to a direction of a beam displacement with respect to the detection surface for different distances to the target point.

8. The method as claimed in claim 1 further comprising:
determining the estimated distance based on a radiometric measured value.

9. The method as claimed in claim 8 , wherein the radiometric measured value is a signal amplitude of the reflected laser radiation received by the detection surface.

10. The method as claimed in claim 8 , wherein the radiometric measured value is a signal-to-noise ratio of the reflected laser radiation received by the detection surface.

11. The method as claimed in claim 1 , the correcting the parallax error further comprising:
correcting the parallax error in the display of the at least one image overlaid with the marker of the target point by adjusting a relative position of the at least one image and of the marker with respect to one another.

12. A laser distance measurement device for contactless measurement of a distance to a target point, the laser distance measurement device comprising:
at least one laser configured to emit laser radiation to the target point;
a receiver having a detection surface configured to acquire reflected laser radiation from the target point;
a camera configured to acquire at least one image of at least one target environment of the target point, and
a screen configured to output a display of the at least one image overlaid with a marker of the target point; and
at least one processor configured to (i) determine an estimated distance to the target point based on a light spot brought about by the reflected laser radiation on the detection surface and (ii) correct a parallax error in the display of the at least one image overlaid with the marker of the target point based on the estimated distance.

13. The laser distance measurement device as claimed in claim 12 , wherein the detection surface of the receiver is a single-photon avalanche photodiode array.

14. The laser distance measurement device as claimed in claim 12 , wherein the laser distance measurement device is a hand-held laser distance measurement device.

Assignees

• Bosch Gmbh Robert

Inventors

• Braun Andreas
• Noe Stefan
• Schmidtke Bernd

Classifications

• G01S17/48

  Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves · CPC title

• G01S17/894 Primary

  Three-dimensional [3D] imaging with simultaneous measurement of time-of-flight at a two-dimensional [2D] array of receiver pixels, e.g. time-of-flight cameras or flash lidar · CPC title

• G01S7/4816

  of receivers alone · CPC title

• G01S7/51 Primary

  Display arrangements · CPC title

• G01S17/08

  for measuring distance only (indirect measurement G01S17/46; active triangulation systems G01S17/48) · CPC title