Portable distance measuring device and method for capturing relative positions

Patent metadata

Field	Value
Publication number	US-10162057-B2
Application number	US-201615379443-A
Country	US
Kind code	B2
Filing date	Dec 14, 2016
Priority date	Dec 14, 2015
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

Some embodiments of the invention relate to a method for capturing a relative position of at least one first spatial point by means of a portable distance measuring device, the method comprising positioning a known reference object, which has known features which may be captured by optical means, said features being arranged in a pattern designed for a resection, at least one first measuring process, comprising measuring a first distance to the first spatial point, and recording a first reference image linked in time with measuring the first distance, the reference object being imaged in the first reference image, and ascertaining the position and orientation of the distance measuring device relative to the reference object comprising identifying the reference object, recalling stored information about the known features of the identified reference object and identifying positions of known features of the reference object in the first reference image.

First claim

What is claimed is:

1. A method for capturing a relative position of at least one first spatial point by means of a portable distance measuring device, the method comprising:
positioning a known three-dimensional reference object in a capture zone of an image sensor of the portable distance measuring device and spaced away from the first spatial point, said known three-dimensional reference object having known features configured to be captured by optical means and are designed for a resection, wherein the features are arranged as a multiplicity of differently formed or patterned surfaces of the three-dimensional reference object;
at least one first measuring process, comprising:
measuring a first distance to the first spatial point, and
recording a first reference image linked in time with measuring the first distance, the reference object being at least partly imaged in the first reference image; and
ascertaining, using image evaluation and resection, the position and orientation of the distance measuring device relative to the reference object comprising:
identifying the reference object;
recalling stored information about known features of the identified reference object; and
identifying positions of known features of the reference object in the first reference image.

2. The method according to claim 1 , wherein:
at least one first and one second measuring process and in that ascertaining of the position and orientation of the distance measuring device relative to the reference object comprises ascertaining a pose change of the distance measuring device between the first measuring process and the second measuring process, the second measuring process comprising:
measuring a second distance to the second spatial point, and
recording a second reference image linked in time with measuring the second distance, the reference object being imaged in the second reference image;

and ascertaining of the pose change comprising:
identifying the reference object;
recalling stored information about known features of the identified reference object; and
identifying positions of known features of the reference object in the first reference image and in the second reference image.

3. The method according to claim 2 , wherein:
the first reference image and the second reference image are recorded using an image sensor of the distance measuring device, and ascertaining the change in pose contains capturing a first spatial pose and a second spatial pose of the distance measuring device, wherein:
the known features are imaged on an image plane of the image sensor in the first reference image and the second reference image,
capturing of the first spatial pose is carried out on the basis of the positions of the known features of the first reference image on the image plane, and
capturing of the second spatial pose is carried out on the basis of the positions of the known features of the second reference image on the image plane.

4. The method according to claim 1 , wherein:
the first measuring process comprises aligning the distance measuring device onto a first spatial point in a first emission direction, and measuring of the first distance to the first spatial point is carried out in the first emission direction.

5. The method according to claim 4 , wherein:
a second measuring process comprises aligning the distance measuring device onto a second spatial point, and measuring of a second distance to the second spatial point is carried out in the second emission direction.

6. The method according to claim 1 , wherein:
the three-dimensional reference object is substantially cubical, tetrahedral, tetrapodic or pyramidal and/or comprises a multiplicity of substantially spherical reference bodies.

7. The method according to claim 1 , wherein:
the three-dimensional reference object is aligned in the direction of gravitational acceleration.

8. The method according to claim 1 , wherein:
the known features have patterns configured as QR codes, Aztec codes or ArUco codes.

9. The method according to claim 1 , wherein:
the three-dimensional reference object is aligned in the direction of gravitational acceleration by freely hanging the reference object on a mount fastened on a surface of the space by means of an adhesive surface, a suction pad, a magnet and/or a screw thread of the mount.

10. The method according to claim 1 , wherein:
fastening the reference object in the space, in particular on a surface of the space means of an adhesive surface, a suction pad, a magnet and/or a screw thread of the reference object.

11. The method according to claim 1 , wherein:
positioning the reference object with a known spatial relationship to a spatial point, wherein the reference object has a labeled placement point for placement on this spatial point, and ascertaining the position and orientation of the distance measuring device relative to the spatial point.

12. The method according to claim 1 , wherein:
feature data, comprising information about known features of at least one known reference object, are stored in a memory unit of the distance measuring device and provided for identifying the reference object.

13. The method according to claim 12 , wherein:
the feature data are provided to a printer or 3D printer, and
the reference object is produced by the a printer or 3D printer.

14. A portable distance measuring device for ascertaining relative coordinates of spatial points, the portable distance measuring device comprising:
a distance measuring unit for measuring distances to spatial points along an emission direction in a space,
an evaluation component configured to derive and provide the measured distances,
a pose determination unit for ascertaining a relative spatial pose of the distance measuring device, and
a memory unit for storing feature data and for providing the feature data to the pose determination unit, the feature data comprising information about known features, configured to be captured by optical means, of one or more known three-dimensional reference objects, wherein the features are arranged as a multiplicity of differently formed or patterned surfaces of the three-dimensional reference objects,
wherein the pose determination unit comprises:
at least one image sensor configured to record reference images linked in time with measuring of a distance by the distance measuring unit, and
an image evaluation component configured to identify the one or more known three-dimensional reference object, imaged in the reference images recorded by the at least one image sensor, on the basis of the provided feature data and use image evaluation and resection to ascertain a pose of the distance measuring device on the basis of the distribution of the features in at least one reference image.

15. The distance measuring device according to claim 14 , wherein:
the image evaluation component is configured to ascertain a change in pose of the distance measuring device on the basis of the distribution of the features in at least two reference images; and
the evaluation component is configured to link the ascertained change in pose with at least two measured distances;
wherein the evaluation component is configured to:
derive and provide the ascertained change in pose,
calculate and provide a distance between two measured spatial points, and/or
calculate and provide positions in a three-dimensional local coordinate system.

16. The distance measuring device according to claim 14 , wherein:
the image sensor and the distance measuring unit are arranged on the dist

Assignees

• Leica Geosystems Ag

Inventors

• Metzler Bernhard
• Aebischer Beat
• Siercks Knut
• Wiltsche Siegfried

Classifications

• G01S5/16

  using electromagnetic waves other than radio waves · CPC title

• G01S5/163

  Determination of attitude (using inertial means G01C9/00; control of attitude G05D1/49) · CPC title

• G01C15/002

  Active optical surveying means (optical plumbing G01C15/105) · CPC title

• G01S17/86

  Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders · CPC title

• G01S7/4813

  Housing arrangements · CPC title