Surveying system

Patent metadata

Field	Value
Publication number	US-10281276-B2
Application number	US-201715719368-A
Country	US
Kind code	B2
Filing date	Sep 28, 2017
Priority date	May 5, 2014
Publication date	May 7, 2019
Grant date	May 7, 2019

Abstract

A system is disclosed that comprises a camera module and a control and evaluation unit. The camera module is designed to be attached to the surveying pole and comprises at least one camera for capturing images. The control and evaluation unit has stored a program with program code so as to control and execute a functionality in which a series of images of the surrounding is captured with the at least one camera; a SLAM-evaluation with a defined algorithm using the series of images is performed, wherein a reference point field is built up and poses for the captured images are determined; and, based on the determined poses, a point cloud comprising 3D-positions of points of the surrounding can be computed by forward intersection using the series of images, particularly by using dense matching algorithm.

First claim

The invention claimed is:

1. A surveying system adapted to determine a position of a position measuring resource being mounted on a surveying pole, the surveying system comprising:
a camera module being attached to the surveying pole and comprising at least one camera for capturing images;
a control and evaluation unit having stored a program with program code so as to control and execute an orientation determining functionality including:
capturing a series of images of the surrounding with the at least one camera when moving along a path through a surrounding, the series comprising an amount of images captured with different poses of the camera, the poses representing respective positions and orientations of the camera;
performing a SLAM-evaluation with a defined algorithm using the series of images, wherein a plurality of respectively corresponding image points are identified in each of several sub-groups of images of the series of images and, based on resection and forward intersection using the plurality of respectively corresponding image points, a reference point field comprising a plurality of reference points of the surrounding, wherein coordinates of the reference points are derived, and the poses for the images are determined;
retrieving determined positions from the surveying system that are adopted by the position measuring resource when moving along the path; and
deriving an external orientation of the at least one camera in the coordinate system of the surveying system at least based on the determined pose for at least one designated image of the series of images and on the determined positions;

a processing unit having stored a program with program code so as to control and execute a single point measurement functionality upon a trigger, the single point measurement functionality including:
determining a trigger-related position, which has been adopted by the position measuring resource at a trigger-related point of time when moving along the path, with the use of the position measuring resource;
determining a trigger-related external orientation, which has been adopted by the at least one camera at the trigger-related point of time; and
determining a position of a bottom of the pole of the surveying system in coordinates of the coordinate system based on at least the trigger-related position and the trigger-related external orientation.

2. The surveying system according to claim 1 , wherein the orientation of the at least one camera is derived based on one or more of the determined poses and is based on data from an inertial measuring unit of the camera module or a multitude of determined positions of the position measuring resource.

3. The surveying system according to claim 1 , wherein the orientation is derived in all three rotational degrees of freedom.

4. The surveying system according to claim 1 , wherein an orientation of the surveying pole is derived based on the poses.

5. The surveying system according to claim 1 , wherein the single point measurement functionality comprises performing a trigger-related section-wise bundle-adjustment for the determination of the trigger-related external orientation, and wherein using only a subset of most recent images of the series of images, the reference point field and the poses within the range of the subset are retroactively re-calculated for the images of the subset and wherein these re-calculated poses are used for deriving the external orientation.

6. The surveying system according to claim 1 , wherein
the control and evaluation unit has stored a program with program code so as to control and execute a spatial representation generation functionality in which the reference point field forms a sparse point cloud that serves for determination of the poses of the images and thus expressly for localisation purposes and,
based on the determined poses, a dense point cloud comprising 3D-positions of points of the surrounding is computed by forward intersection using the images of the series of images.

7. The surveying system according to claim 6 , wherein the control and evaluation unit is configured so that the spatial representation generation functionality is controlled and executed such that determined positions of the position measuring resource for points that have been adopted on the path are received by the control and evaluation unit from the surveying system and the dense point cloud is scaled using the received determined positions.

8. The surveying system according to claim 6 , wherein the control and evaluation unit is configured so that the spatial representation generation functionality is controlled and executed such that a graphical reproduction is generated for the dense point cloud, the graphical reproduction being displayable by display means of the surveying system.

9. The surveying system according to claim 1 , wherein the camera module comprises a camera-arrangement being configured such a way that panoramic images with a field of view of 360° at least in azimuthal direction are capturable.

10. The surveying system according to claim 9 , wherein a sensor unit is fixedly integrated into the common housing, the sensor unit comprising at least one of the following sensors:
an inertial measuring unit,
a gyroscope,
a tilt sensor, and
a magnetic compass.

11. The surveying system according to claim 1 , wherein the position measuring resource is a GNSS-antenna or a retro-reflector.

12. The surveying system according to claim 1 , wherein the surveying pole is a hand-carried surveying pole.

13. A surveying subsystem being adapted to be used as part of a surveying system that is adapted to determine positions of a position measuring resource being mounted on a surveying pole, the surveying subsystem comprising:
a camera module designed to be linked with the position measuring resource and comprising at least one camera for capturing images; and
a control and evaluation unit having stored a program with program code so as to control and execute a data reduction functionality in which, when moving along a path through a surrounding:
captures a series of images of the surrounding with the at least one camera, the series of images comprising an amount of images captured with different poses of the camera representing respective positions and orientations of the camera;
performing a SLAM-evaluation with a defined algorithm using the series of images, wherein a plurality of respectively corresponding image points are identified in each of several sub-groups of images of the series of images and, based on resection and forward intersection using the plurality of respectively corresponding image points:
a reference point field is built up comprising a plurality of reference points of the surrounding, wherein coordinates of the reference points are derived, and
the poses for the images are determined;

based on the determined poses, computing a point cloud comprising 3D-positions of points of the surrounding by forward intersection using the series of images;
identify pre-defined or user-defined objects in the images; and
modify or delete 3D-positions of points being connected to the identified objects in the image.

14. The subsystem according to claim 13 , wherein the 3D-positions are modified or deleted such that individual characteristics of the identified objects are not identifiable in the computed point cloud.

15. The subsystem according to claim 13 , wherein image data being connected to the identified objects in the image are modified or deleted.

16. The subsystem according to claim 13 , wherein the

Assignees

• Hexagon Technology Ct Gmbh

Inventors

• Siercks Knut
• Metzler Bernhard
• Van Der Zwan Elmar Vincent
• Fidler Thomas
• Parys Roman
• Velizhev Alexander
• Scheja Jochen

Classifications

• H04N23/51

  Housings · CPC title

• H04N23/55

  Optical parts specially adapted for electronic image sensors; Mounting thereof · CPC title

• H04N23/90

  Arrangement of cameras or camera modules, e.g. multiple cameras in TV studios or sports stadiums · CPC title

• H04N23/635

  Region indicators; Field of view indicators · CPC title

• H04N23/69

  Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming · CPC title