US 11,754,386 B2
Method and system for capturing and measuring the position of a component with respect to a reference position and the translation and rotation of a component moving relative to a reference system
Arne Heymer, Cologne (DE)
Assigned to Ford Global Technologies, LLC, Dearborn, MI (US)
Filed by Ford Global Technologies, LLC, Dearborn, MI (US)
Filed on Feb. 6, 2020, as Appl. No. 16/783,636.
Claims priority of application No. 102019201526.3 (DE), filed on Feb. 6, 2019.
Prior Publication US 2020/0249009 A1, Aug. 6, 2020
Int. Cl. G06K 9/00 (2022.01); G01B 11/00 (2006.01); G06T 7/73 (2017.01); G06T 3/00 (2006.01); G02B 27/64 (2006.01)
CPC G01B 11/002 (2013.01) [G02B 27/644 (2013.01); G06T 3/0006 (2013.01); G06T 7/73 (2017.01); G06T 7/74 (2017.01); G06T 2207/30204 (2013.01); G06T 2207/30252 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for capturing and measuring translation and rotation of a component moving relative to a reference system, the method comprising:
a) providing a marker on the component, wherein the marker is a two-dimensional entity with at least three points that do not lie on a straight line, and wherein each of the at least three points lie on a same plane;
b) providing a measurement system having a camera arranged in the reference system which translation and/or rotation of the moving component are captured, the measurement system also having an evaluation unit connected to the camera, the evaluation unit configured to store a geometry of an upper side of the marker and the at least three points, wherein the evaluation unit captures and stores at least one parameter selected from at least one of a distance of the camera from the marker, a focal length of an objective lens of the camera, and an active sensor width and active sensor height of a sensor of the camera;
c) aligning the camera with the at least three points;
d) capturing a first image of the marker and of the component in a first position and determining a location of the at least three points in the first image, wherein x- and y-coordinates of the at least three points and alignment of the at least three points in an image plane of the first image are determined, and wherein the actual position occupied by each of the at least three points are obtained by setting a height of the first image to a height of the active sensor and a width of the first image to a width of the active sensor;
e) capturing a second image of the marker and of the component in a second position different than the first position and determining a location of the at least three points in the second image, wherein the x- and y-coordinates of the at least three points and alignment of the at least three points in the image plane of the second image are determined, and wherein for each of the first image and the second image a circumcircle of a triangle formed by the at least three points is calculated from x- and y-coordinates of the at least three points and a center of the circumcircle is ascertained and said center of the circumcircle is used as a centerpoint of the marker, and wherein an optical axis of the camera is directed in an initial setting onto the centerpoint of the marker, and wherein the actual positions occupied by each of the at least three points are obtained by setting a height of the second image to the height of the active sensor and a width of the second image to the width of the active sensor; and
f) calculating a translation and/or rotation of the component in three-dimensional space between the first and the second position of the component.