Surveying system

Patent metadata

Field	Value
Publication number	US-11054258-B2
Application number	US-202016847240-A
Country	US
Kind code	B2
Filing date	Apr 13, 2020
Priority date	May 5, 2014
Publication date	Jul 6, 2021
Grant date	Jul 6, 2021

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 subsystem comprising:
a camera module that is adapted to determine positions of a position measuring resource that is mounted on a surveying pole and includes a GNSS-antenna or a retro-reflector, wherein:
the camera module is configured to be attached to the surveying pole; and
the camera module comprises:
two cameras arranged relative to each other with substantially diametrically opposing viewing directions, each of the two cameras having a fisheye lens and being adapted to capture wide panoramic images; and

a control and evaluation unit, having stored a program with program code so as to control and execute a spatial representation generation functionality in which, when moving along a path through a surrounding:
a series of panoramic images of the surrounding is captured with the two cameras, the series comprising an amount of panoramic images captured with different poses of the two cameras, the poses representing respective positions and orientations of the two cameras,
a SLAM-evaluation with a defined algorithm using the series of panoramic images is performed, wherein a plurality of respectively corresponding image points are identified in each of several sub-groups of panoramic images of the series of panoramic 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 panoramic images are determined.

2. The surveying subsystem according to claim 1 , wherein,
the control and evaluation unit is configured so that the spatial representation generation functionality is controlled and executed in such a way, that the poses for the panoramic images are determined by applying a defined optical imaging method taking account of the optical properties of the fisheye lens, wherein:
different imaging planes are used with the optical imaging method, and/or
one of the following mapping functions is used:
stereographic mapping function,
equidistant mapping function,
equisolid angle mapping function, and
orthographic mapping function.

3. The surveying subsystem according to claim 1 , wherein:
the control and evaluation unit is configured so that the spatial representation generation functionality is controlled and executed in such a way, that the reference point field forms a sparse point cloud that serves for determination of the poses of the two camera and thus expressly for localisation purposes and,
based on the determined poses, a dense point cloud that includes 3D-positions of points of the surrounding is computed by forward intersection using the images of the first series of images and images of a second series of images.

4. The surveying subsystem according to claim 3 , wherein,
the control and evaluation unit is configured so that the spatial representation generation functionality is controlled and executed in such a way, 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, and particularly geo-referenced, with help of the received determined positions.

5. The surveying subsystem according to claim 3 , wherein,
the control and evaluation unit is configured so that the spatial representation generation functionality is controlled and executed in such a way, that a graphical reproduction is generated for the dense point cloud, the graphical reproduction being displayable by display means of the surveying system.

6. The surveying subsystem according to claim 1 , wherein,
the position measuring resource comprises a GNSS-antenna or a retro-reflector.

7. The surveying subsystem according to claim 1 , wherein,
orientations of at least one camera in six degrees of freedom are derived based on:
one or more of the determined poses; and
data from an inertial measuring unit of the camera module.

8. A surveying system comprising:
a hand-carried surveying pole,
a position measuring resource being mounted on the surveying pole, wherein positions of the position measuring resource are determinable by the surveying system, and
the surveying subsystem according to claim 1 .

9. The surveying system according to claim 8 , wherein,
the position measuring resource comprises a GNSS-antenna or a retro-reflector.

10. The surveying subsystem according to claim 1 , wherein orientations of at least one camera in six degrees of freedom are derived based on one or more of the determined poses and based on a multitude of determined positions of the position measuring resource.

11. The surveying subsystem according to claim 1 , wherein orientations of at least one camera in six degrees of freedom are derived based on one or more of the determined poses and based on a traveling history for the moved path.

12. A camera module to be used as part of a surveying system that is adapted to determine positions of a position measuring resource that is mounted on a surveying pole and includes a GNSS-antenna or a retro-reflector, wherein:
the camera module is configured to be attached to the surveying pole; and
the camera module comprises:
two cameras arranged relative to each other with substantially diametrically opposing viewing directions, each of the two cameras having a fisheye lens and being adapted to capture wide panoramic images, wherein each of the two cameras has a field of view of at least 180° in the respective viewing directions regarding at least one axis;
a control and evaluation unit, having stored a program with program code so as to control and execute a spatial representation generation functionality in which, when moving along a path through a surrounding:
a series of panoramic images of the surrounding is captured with the at least two cameras, the series comprising an amount of panoramic images captured with different poses of the cameras, the poses representing respective positions and orientations of the cameras,
a SLAM-evaluation with a defined algorithm using the series of panoramic images is performed, wherein a plurality of respectively corresponding image points are identified in each of several sub-groups of panoramic images of the series of panoramic 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 panoramic images are determined.

13. The surveying subsystem according to claim 12 , wherein the control and evaluation unit is configured so that the spatial representation generation functionality is controlled and executed in such a way, that the poses for the panoramic images are determined by applying a defined optical imaging method taking account of the optical properties of the fisheye lens, wherein:
different imaging planes are used with the optical imaging method, and/or
one of the following mapping functions is used:
stereographic mapping function,
equidistant mapping function,
equisolid angle mapping function, and
orthographic mapping function.

14. The surveying subsystem according to claim 12 , wherein:
the control and evaluation unit is configured so that the spatial representation generation functionality is controlled and executed in such a way, that the reference point field fo

Assignees

• Hexagon Technology Ct Gmbh

Inventors

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

Classifications

• H04N23/635

  Region indicators; Field of view indicators · CPC title

• H04N23/57

  Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices · 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

• H04N23/63

  by using electronic viewfinders · CPC title

• H04N23/55

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