Surveying system

• US 10,605,601 B2
• Filed: 01/22/2019
• Issued: 03/31/2020
• Est. Priority Date: 05/05/2014
• Status: Active Grant

• Current Assignee: Hexagon Technology Center GmbH (Hexagon AB)
• Original Assignee: Hexagon Technology Center GmbH (Hexagon AB)
• Inventors: Siercks, Knut, Metzler, Bernhard, Van Der Zwan, Elmar Vincent, Fidler, Thomas, Parys, Roman, Velizhev, Alexander, Scheja, Jochen
• Primary Examiner(s): Williams, Jeffery A
• Application Number:
  US16/253,522
• Publication Number:
  US 20190226846A1
• Time in Patent Office: 434 Days
• Field of Search: 348135
• CPC Class Codes: G01C 11/02 Picture taking arrangements specially adapted for photogrammetry or photographic surveying, e.g. controlling overlapping of pictures
• CPC Class Codes: G01C 11/04 Interpretation of pictures
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105
• CPC Class Codes: G01C 15/006 Detectors therefor
• CPC Class Codes: G01C 25/005 initial alignment, calibration or starting-up of inertial devices
• CPC Class Codes: G01S 19/13 Receivers
• CPC Class Codes: G01S 19/14 specially adapted for specific applications
• CPC Class Codes: G06T 2207/10028 Range image; Depth image; 3D point clouds
• CPC Class Codes: G06T 2207/30244 Camera pose
• CPC Class Codes: G06T 7/0002 Inspection of images, e.g. flaw detection
• CPC Class Codes: G06T 7/0004 Industrial image inspection
• CPC Class Codes: G06T 7/579 from motion
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80
• CPC Class Codes: G06T 7/97 Determining parameters from multiple pictures depth or shape recovery from multiple images G06T7/55; stereo camera calibration G06T7/85
• CPC Class Codes: H04N 23/51 Housings
• CPC Class Codes: H04N 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof
• CPC Class Codes: H04N 23/57 Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices
• CPC Class Codes: H04N 23/63 by using electronic viewfinders
• CPC Class Codes: H04N 23/635 Region indicators; Field of view indicators
• CPC Class Codes: H04N 23/69 Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming
• CPC Class Codes: H04N 23/698 : for achieving an enlarged field of view, e.g. panoramic image capture
• CPC Class Codes: H04N 23/90 : Arrangement of cameras or camera modules, e.g. multiple cameras in TV studios or sports stadiums

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.

Claims

1. A surveying subsystem comprising a camera module and a control and evaluation unit, wherein the surveying subsystem is configured to be used as part of a surveying system adapted to determine positions of a position measuring resource, particularly wherein the position measuring resource is a GNSS-antenna or a retro-reflector,

the camera module comprising at least one camera for capturing images and particularly being designed to be attached to the position measuring resource,

the control and evaluation unit having stored a program with program code so as to control and execute a 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 with use of a feature detection process for detecting corresponding features, particularly by means of feature tracking, especially a KLT-algorithm (Kanade-Lucas-Tomasi), and/or by means of feature matching, especially a SIFT-, SURF-, BRISK- or BRIEF-algorithm, 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,

wherein the control and evaluation unit comprises several diversified units,

wherein at least a first unit, particularly an FPGA or a GPU (i.e. as abbreviation for graphical processing unit), carries out at least part of the feature detection process for identifying the plurality of respectively corresponding image points, and

wherein at least another, second unit, particularly a CPU, carries out determining of the poses.

2. The subsystem according to claim 1, wherein the first and second units are built together as one SoC (i.e. as abbreviation for system on a chip).

3. The subsystem according to claim 1, wherein the first and the second unit are disposed within the camera module.

4. The subsystem according to claim 1, wherein the first unit is disposed within the camera module and the second unit is a laptop, a tablet-PC, a smartphone, a processing unit of a handheld controller/datalogger of the surveying system, a processing unit of a GNSS-module of the surveying system, a processing unit of a surveying station, particularly total station, of the surveying system or a surveying site server, particularly being installed in a car.

5. The subsystem according to claim 1, wherein

the camera module is designed to be attached to a hand-carried surveying pole as part of a surveying system that is adapted to determine positions of a position measuring resource, and the position measuring resource also being mountable on the surveying pole.

8. The subsystem according to claim 1, wherein

the at least one other unit is a laptop, a tablet-PC, a smartphone, a processing unit of a handheld controller/datalogger of the surveying system, a processing unit of a GNSS-module of the surveying system or a surveying site server, particularly being installed in a car.

9. The subsystem according to claim 1, wherein

several other units, being disposed externally to the camera module, carry out at least parts of computing of the spatial representation in a decentralised manner, the several other units particularly being several smartphones.

10. The subsystem according to claim 1, wherein

at least one unit carrying out a part of identifying the plurality of respectively corresponding image points and/or determining the poses is designed so as to be carriable in a backpack of an operator.

11. The subsystem according to claim 1, wherein

at least one unit carrying out a part of identifying the plurality of respectively corresponding image points and/or determining the poses is a laptop, a tablet-PC, a smartphone, a processing unit of a handheld controller/datalogger of the surveying system, a processing unit of a GNSS-module of the surveying system or a surveying site server, particularly being installed in a car.

12. The subsystem according to claim 1, wherein

the camera module is designed to be attached to a hand-carried surveying pole as part of a surveying system that is adapted to determine positions of a position measuring resource, and the position measuring resource also being mountable on the surveying pole.

6. A surveying subsystem comprising a camera module and a control and evaluation unit, wherein the surveying subsystem is configured to be used as part of a surveying system adapted to determine positions of a position measuring resource, particularly wherein the position measuring resource is a GNSS-antenna or a retro-reflector,

the camera module comprising at least one camera for capturing images, wherein the camera module is built as one single integrated physical unit being designed to be attached to the position measuring resource, and

the control and evaluation unit having stored a program with program code so as to control and execute a 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, and the poses for the images are determined,

a spatial representation, particularly a point cloud, comprising 3d-information about the surrounding is computed by forward intersection using the series of images and the determined poses, particularly by using a dense matching algorithm,

wherein the control and evaluation unit comprises several diversified units, wherein

at least one unit, being integrated in the camera module, carries out at least part of the SLAM-evaluation and

at least one other unit, being disposed externally to the camera module, carries out at least parts of computing of the spatial representation.

7. The subsystem according to claim 6, wherein the at least one other unit is a cloud server.