Method and device for the contactless optical determination of the 3D position of an object

• US 20070009149A1
• Filed: 03/24/2006
• Published: 01/11/2007
• Est. Priority Date: 09/26/2003
• Status: Active Grant

• Current Assignee: Micro-Epsilon Messtechnik GmbH & Co., KG
• Original Assignee: Micro-Epsilon Messtechnik GmbH & Co., KG
• Inventors: Wagner, Robert, Hesse, Rainer
• Granted Patent: US 8,064,686 B2
• Time in Patent Office: Days
• US Class Current: 382/154
• CPC Class Codes: G06T 7/73 using feature-based methods

Abstract

A device for the contactless optical determination of the position of an object. In particular, the present invention provides a method and device for the contactless optical determination of the 3D position of an object wherein an image of the object is generated by means of a camera and the 3D position of the object is calculated from the camera image based on the image information about detected geometrical characteristics. Determination of the 3D position of the object includes determination of the 3D position and the 3D orientation of the object.

Claims

1. A method for the contactless optical determination of the 3D position of an object wherein the determination of the 3D position includes the determination of the 3D position and the 3D orientation of the object and wherein the geometrical characteristics of the object are known, comprising:

generating an image of the object by means of a camera; and

calculating the 3D position of the object from the camera image based on image information about the detected geometrical characteristics,

wherein the camera is held stationary with a fixed alignment, the complete determination of the 3D position is carried out by means of a single image acquisition using the camera, a known 3D-position of the geometric characteristics is assigned in each case to the corresponding two-dimensional image information.

2. The method according to claim 1, further comprising preparing a system of equations for all free parameters of the imaging process.

3. The method according to claim 2, wherein non-linear optimization methods are used to solve an over-determined system of equations.

4. The method according to claim 1, wherein the alignment of the camera is predetermined.

5. The method according to claim 1, wherein general mathematically describable contours and shapes are used as geometrical characteristics.

6. The method according to claim 5, wherein at least one of points, straight lines, angles, circles, elliptical contours, or conic sections are used as geometrical characteristics.

7. The method according to claim 1, wherein the camera is calibrated with the help of the geometrical characteristics.

8. The method according to claim 7, wherein internal camera parameters are determined within the framework of a calibration.

9. The method according to claim 1, characterized in that the 3D position of the object is determined in relation to a fixed coordinate system.

10. The method according to claim 1, wherein the 3D position of the object is determined in relation to at least one of a camera coordinate system, an object coordinate system, or a world coordinate system.

11. The method according to claim 1, wherein the 3D position of the object is determined in relation to a dynamic coordinate system.

12. The method according to claim 1, wherein the image of the object is generated using one or more additional cameras.

13. The method according to claim 12, wherein the image of the object is generated from different camera angles.

14. The method according to claim 12, wherein the quality of the calculated 3D position of the object is determined by means of the additional images, and, if necessary, corrections are made.

15. The method according to claim 1, wherein errors in the determination of the 3D position are compensated or corrected by means of sensors.

16. The method according to claim 1 wherein at least one of a tracking measurement or a camber measurement is carried out on a motor vehicle on the basis of geometrical characteristics of a rim of the motor vehicle.

17. The method according to claim 16, wherein automatically marked locations on the rim provide the geometrical characteristics.

18. The method according to claim 17, wherein the marked locations provided may be interactively accepted or rejected by a user.

19. A device for the contactless optical determination of the 3D position of an object, wherein the determination of the 3D position includes the determination of the 3D position and the 3D orientation of the object and wherein the geometrical characteristics of the object are known, comprising:

a camera for generating an image of the object, wherein the 3D position of the object can be calculated from the camera image based on the image information about the known geometrical characteristics.

20. The device according to claim 19, wherein the camera is stationary.

21. The device according to claim 19, further comprising at least one computer for evaluating the camera images and for calculating the 3D position.

22. The device according to claim 21, wherein the computer has image processing software.