Fully automatic position and alignment determination method for a terrestrial laser scanner and method for ascertaining the suitability of a position for a deployment for surveying

Patent metadata

Field	Value
Publication number	US-11604065-B2
Application number	US-202016876041-A
Country	US
Kind code	B2
Filing date	May 16, 2020
Priority date	May 17, 2019
Publication date	Mar 14, 2023
Grant date	Mar 14, 2023

Abstract

One aspect of the invention relates to a fully automatic method for calculating the current, geo-referenced position and alignment of a terrestrial scan-surveying device in situ on the basis of a current panoramic image recorded by the surveying device and at least one stored, geo-referenced 3D scan panoramic image.

First claim

What is claimed is:

1. A fully automatic method for determining the current, geo-referenced position and alignment of a terrestrial surveying device with scan functionality at a current location based on a set of stored, geo-referenced three-dimensional (3D) scan panoramic images, the method comprising:
recording a panoramic image with the surveying device from the current location, the recorded panoramic image comprising a plurality of object points;
identifying at least one 3D scan panoramic image with a plurality of object points corresponding to the recorded panoramic image by means of image matching;
determining respective geo-referenced 3D coordinates of the corresponding plurality of object points in the recorded panoramic image on the basis of the identified 3D scan panoramic image; and
calculating a current geo-referenced position and alignment of the surveying device based on the positions of the corresponding plurality of object points in the recorded panoramic image and their determined geo-referenced 3D coordinates.

2. The method according to claim 1 , wherein the stored 3D scan panoramic images are each based on two-dimensional (2D ) panoramic images and associated 3 D point clouds or the recorded panoramic image is a 2D image.

3. The method according to claim 1 , wherein the stored 3D scan panoramic images each comprise color channels based on digital photography and a depth channel based on laser scanning.

4. The method according to claim 1 , wherein the stored 3D scan panoramic images are in the form of cubic or spherical projections.

5. The method according to claim 1 , wherein the set of stored 3D scan panoramic images comprise spatially interlinked images of a surrounding region forming a unit.

6. The method according to claim 1 , further comprising:
moving the surveying device the current location along a path to a second location; and
continuously recording a series of images with the surveying device as the surveying device is moved using a SLAM process, wherein the identified 3D scan panoramic image is employed as an image of the image series,
wherein the image series of the SLAM process is completed by recording a final image at the second location,
wherein a 3D point cloud is recorded at the second location by means of the surveying device, and
the 3D point cloud is registered on the basis of the SLAM process relative to the identified 3D scan panoramic image.

7. A method according to claim 1 , wherein the number of stored 3D scan panoramic images to be employed for the location determination is adjusted to the existing measurement situation.

8. A method according to claim 7 , wherein in the context of the adjustment, the number of stored 3D scan panoramic images to be used for the location determination is set depending on a measure of the similarity between the recorded panoramic image and the identified 3D scan panoramic image.

9. A method according to claim 8 , the measure of similarity represents a measure for a difference in position between the current location and the recording location of the respective, identified 3D scan panoramic image.

10. A method according to claim 7 , wherein in the context of the adjustment, the number of stored 3D scan panoramic images used for the location determination is set based on a character of the surroundings of the current location determined on the basis of the recorded panoramic image.

11. A method according to claim 7 , wherein in the context of the adjustment, the number of stored 3D scan panoramic images used for the location determination is set depending on a desired degree of precision for the position or alignment to be determined.

12. The method according to claim 1 , wherein the image matching is based on machine learning, deep learning, or corresponding object points are determined by means of feature matching algorithms.

13. The method according to claim 1 , wherein the calculation of the current location takes place by means of re-sectioning.

14. A terrestrial surveying device with scan functionality and with a control and evaluation unit that is configured to perform the method of claim 1 .

15. A computer program product that is stored on a non-transitory machine-readable program code that is suitable for carrying out the method according to claim 1 .

Assignees

• Hexagon Technology Ct Gmbh

Inventors

• Metzler Bernhard
• Scheja Jochen

Classifications

• G01C15/002 Primary

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

• G01C21/20

  Instruments for performing navigational calculations (G01C21/24, G01C21/26 take precedence) · CPC title

• G06T2207/30244

  Camera pose · CPC title

• G06V20/10

  Terrestrial scenes (scenes under surveillance with static cameras G06V20/52; scenes perceived from the exterior of a vehicle G06V20/56; scenes perceived from the interior of a vehicle G06V20/59) · CPC title

• G06T7/521

  from laser ranging, e.g. using interferometry; from the projection of structured light · CPC title