Surveying system

Patent metadata

Field	Value
Publication number	US-10274316-B2
Application number	US-201615373280-A
Country	US
Kind code	B2
Filing date	Dec 8, 2016
Priority date	May 5, 2014
Publication date	Apr 30, 2019
Grant date	Apr 30, 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 subsystem comprising:
a camera module;
a control and evaluation unit, wherein the surveying subsystem is adapted to be used as part of a surveying system that is adapted to determine positions of a position measuring resource that includes a GNSS-antenna or a retro-reflector; and
a hand-carried surveying pole on which the position measuring resource and the camera module are mounted, wherein:
the camera module comprising at least one camera for capturing images;
the control and evaluation unit has stored thereon a program with program code that, when executed, controls and executes a spatial representation generation functionality in which, when moving along a path through a surrounding:
a series of images of the surrounding is captured with the at least one camera, the series comprising an amount of images captured with different poses of the camera, the poses representing respective positions and orientations of the camera,
a SLAM-evaluation with a defined algorithm using the series of images is performed, 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,
the poses for the images are determined, and
a quality indicative output is generated concerning the measurement uncertainty of a 3D-position for at least one point of the surrounding to be computable by forward intersection using the images of the series of images and the determined poses.

2. The surveying subsystem according to claim 1 , wherein,
the forward intersection implies using a variance-covariance-matrix, particularly wherein the forward intersection is carried out by use of a least square method, and the quality indicative output is derived from the variance-covariance-matrix.

3. The surveying subsystem according to claim 1 , wherein,
the quality indicative output represents an uncertainty regarding the precision with which the 3D-position for the at least one point is computable or computed, particularly wherein the quality indicative output is influenced at least by:
a precision with which image-positions for the image points within the images is determinable,
an amount of images which are usable out of the series of images for the computation of the 3D-position for at least one point of the surrounding; and
a length of the baselines of the poses of the usable images.

4. The surveying subsystem according to claim 1 , wherein,
based on the determined poses, a point cloud comprising 3D-positions of points of the surrounding is computed by forward intersection using the images of the series of images;
the quality indicative output is generated for at least one of the computed points of the point cloud; and
the quality indicative output is generated for a subset of points of the point cloud referring to a corresponding amount of poses which the subset is determined from.

5. The surveying subsystem according to claim 4 , wherein:
a graphical reproduction is generated for the point cloud representing the quality indicative output, the graphical reproduction being displayable by display means of the surveying system, thus providing for a feedback to a user about already acquired data, so that the already acquired data can be checked regarding its quality.

6. The surveying subsystem according to claim 4 , wherein,
the quality indicative output is represented by a coloured point cloud, a scaled indication or a specific sign displayable on display means of the surveying system.

7. The surveying subsystem according to claim 4 , wherein:
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 point cloud is scaled with help of the received determined positions.

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

9. The surveying subsystem according to claim 1 , wherein,
the camera module comprises a camera-arrangement being built and designed in such a way that panoramic images with a field of view of 360° at least in azimuthal direction are capturable, particularly wherein the camera-arrangement comprises at least two cameras, especially at least four cameras, arranged in a common housing of the camera module.

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

11. 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
a surveying subsystem according to claim 1 .

12. A surveying subsystem comprising:
a camera module;
a profiler; and
a control and evaluation unit, wherein the surveying subsystem is adapted 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 hand-carried surveying pole and that includes a GNSS-antenna or a retro-reflector, wherein:
the camera module is configured to be brought into a fixed mechanical connection with the position measuring resource by being attached to the surveying pole, and includes at least one camera for capturing images;
the profiler is configured to be brought into a fixed mechanical connection with the position measuring resource by being attached to the surveying pole, and being adapted:
for emission of a rotating laser beam; and
for reception and detection of a returning part of the emitted laser beam being scattered back from points of a surrounding,
the profiler further being provided with an electronic distance measuring functionality as well as an angle measuring functionality for the rotating laser beam so that profiler measurement data comprising distance and angle information is gatherable, and

the control and evaluation unit has stored thereon a program with program code that, when executed, controls and executes a spatial representation generation functionality in which, when moving along a path through the surrounding:
a series of images of the surrounding is captured with the camera, the series including a plurality of images captured with different poses of the camera, from different points on the path and with different orientations of the camera;
a SLAM-evaluation with a defined algorithm using the series of images is performed, 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,

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;
a 6-dof-travelling-hi story including translational and rotational infor

Assignees

• Hexagon Technology Ct Gmbh

Inventors

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

Classifications

• H04N23/698

  for achieving an enlarged field of view, e.g. panoramic image capture · CPC title

• H04N23/57

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

• H04N23/55

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