Target point recognition method and surveying instrument

• US 9,046,361 B2
• Filed: 07/07/2011
• Issued: 06/02/2015
• Est. Priority Date: 07/07/2010
• Status: Active Grant

• Current Assignee: Leica Geosystems Holdings AG (Hexagon AB)
• Original Assignee: Leica Geosystems Holdings AG (Hexagon AB)
• Inventors: Nindl, Daniel, Zogg, Hans-Martin, Lienhart, Werner, Kotzur, Norbert
• Primary Examiner(s): Patel, Jay
• Assistant Examiner(s): Aghevli, Reza
• Application Number:
  US13/515,438
• Publication Number:
  US 20120249783A1
• Time in Patent Office: 1,426 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G01C 1/04 combined with cameras
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105

Abstract

Target point recognition method including emitting electromagnetic radiation to illuminate targets, moving the scanning beam within a predetermined angular range in order to scan the surveying environment, detecting reflections of the electromagnetic radiation on the targets, wherein the targets are defining the target points, and determining the angle to the target points. The method further including a capturing procedure with capturing an overall image of the surveying environment, wherein the overall image comprises at least one single image taken by the camera, and determining target points and their angle on the overall image by image processing by matching targets with one or more predetermined search criteria, storing the target points together with their angle a data base, and displaying the overall image together with marks for indicating a position of the target points detected within the scanning procedure and the capturing procedure in the overall image.

Claims

1. A target point recognition method for an automatic search of target points in a surveying environment in advance of a precise measurement of these points, wherein an angle to the target points is measured with a surveying instrument, the surveying instrument comprising means for measuring angles, a camera and processing means for data storing and controlling the following steps in an automated manner after starting the search, the method comprising:

a scanning procedure including;

emitting electromagnetic radiation in form of a scanning beam to illuminate targets;

moving the scanning beam within a predetermined angular range in order to scan the surveying environment;

detecting reflections of the electromagnetic radiation on the targets, wherein the targets are defining the target points; and

determining the angle to the target points,

a capturing procedure including;

capturing an overall image of the surveying environment, wherein the overall image comprises at least one single image taken by the camera; and

detecting target points and determining their angle on the overall image by image processing by matching targets with one or more predetermined search criteria;

storing the target points together with their angle in a data base; and

displaying the overall image together with marks for indicating a position of the target points detected within the scanning procedure and the capturing procedure in the overall image;

wherein

the electromagnetic radiation is emitted in form of a laser fan to illuminate targets;

the predetermined search criteria at least provide to detect a target representing a predetermined structure or pattern;

the scanning procedure and the capturing procedure are, as sub-procedures, part of a recognition process for detecting the target points; and

the target points are displayed by using different marks captured by different sub-procedures of the recognition process with which the target point has been recognized.

2. The target point recognition method according to claim 1, wherein the angle to the target points measured includes a horizontal and a vertical angle.

3. The target point recognition method according to claim 1, wherein capturing the overall image of the surveying environment includes capturing several images and stitching the pictures together to generate a panoramic view.

4. The target point recognition method according to claim 1, wherein target points are manually verified and added to the data base and/or detected or verified target points are manually chosen and removed from the data base.

5. The target point recognition method according to claim 1, wherein a distance and angles to a target point are determined within a precise measurement, after manually or automatically selecting the target point.

6. The target point recognition method according to claim 1, wherein the scanning procedure and the capturing procedure are executed in an at least partly in time overlapping manner.

7. The target point recognition method claim 1, further comprising verifying the target point and gathering additional information of the target including pole height or reflector type by means of image processing.

8. The target point recognition method according to claim 1, wherein the scanning procedure and the capturing procedure are, as sub-procedures, part of a recognition process for detecting the target points, wherein the recognition process further comprises other sub-procedures, wherein the sub-procedures are performed by use of different sensor types including an automatic-target-recognition-sensor, an over-view camera, an on-axes camera, a thermographical sensor and/or a range imaging module.

9. The target point recognition method according to claim 8, wherein the target points are displayed in combination with a virtual environment and/or in combination with the overall image of the surveying environment, in dependency of the search criteria used for determining the respective target point, wherein the size of the representing marks depends on the respective target points'"'"' distance from the surveying instrument.

10. The target point recognition method according to claim 1, wherein target point information, including their distance and angles to the surveying instrument, of some or all of the target points are transferred into an existing coordinate system.

11. The target point recognition method according to claim 1, wherein the search criteria provide to verify whether a target point is a retro-reflecting target and/or a signal emitting target and/or a target representing a predetermined structure or pattern and/or a temporarily-signalized target and/or a coded target and/or a half-corresponding target.

12. The target point recognition method according to claim 1, wherein a scanning of the surveying environment and/or a scanning within a predefined surveying area is performed by laser scanning or by moving the scanning beam within a predetermined angular range and/or the surveying environment is scanned rotating the scanning beam over a full circle providing at least a partial hemisphere.

13. The target point recognition method according to claim 1, wherein a scanning of the surveying environment and/or a scanning within a predefined surveying area defined by a frame is performed by laser scanning or by moving the scanning beam within a predetermined angular range and/or the surveying environment is scanned rotating the scanning beam over a full circle providing a full dome of the surveying environment.

14. The target point recognition method according to claim 1, wherein the processing means control the repeating of the steps of the method until the whole surveying environment is scanned and until a scan of the surveying environment is performed with each sensor type.

15. A surveying instrument comprising:

display means,

scanning means for emitting electromagnetic radiation in form of a scanning beam and for detecting reflections;

a distance measuring unit,

an angle determination unit;

a camera for capturing images;

a processing unit for image processing, data storing and providing a searching functionality for searching for target points, that are defined by targets, and measuring an angle, including a horizontal and a vertical angle, to the target points in advance of a precise measurement of these target points,

wherein, within the searching functionality, the processing unit is adapted to perform respectively and control the following steps in an automated manner;

a scanning procedure by use of scanning means including;

emitting electromagnetic radiation in form of a scanning beam in the form of a laser fan to illuminate targets;

moving the scanning beam within a predetermined angular range in order to scan the surveying environment;

detecting reflections of the electromagnetic radiation on the targets, wherein the targets are defining the target points; and

determining the angle to the target points;

a capturing procedure including;

capturing an overall image of the surveying environment, wherein the overall image comprises at least one single image taken by the camera, including several images stitched together to a panoramic view; and

detecting target points and determining their angle on the overall image by image processing by matching targets with one or more predetermined search criteria;

storing the target points together with their angle in a data base; and

displaying the overall image together with marks for indicating a position of the target points detected within the scanning procedure and the capturing procedure in the overall images;

wherein

the predetermined search criteria at least provide to detect a target representing a predetermined structure or pattern;

the scanning procedure and the capturing procedure are, as sub-procedures, part of a recognition process for detecting the target points; and

the target points are displayed by using different marks captured by different sub-procedures of the recognition process with which the target point has been recognized.

16. The surveying instrument according to claim 15, wherein target points are detected with at least an over-view camera or an automatic-target-recognition-sensor.

17. The surveying instrument according to claim 15, further comprising control means for manually selecting and/or deselecting target points.

18. The surveying instrument according to claim 15, wherein the scanning means comprises an electromagnetic radiation emitter for emitting a scanning beam, moving means for moving the scanning beam, a reflections detector for detecting reflections on the targets.