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

Abstract

A method for capturing and measuring translation and/or rotation of a component moving relative to a reference system includes providing a marker on the component and providing a measurement system having a camera arranged in the reference system. The marker has at least three points which do not lie on a straight line on an upper side of the marker and the camera has an evaluation unit and memory that stores a geometry of the upper side including the at least three points. The camera is aligned with the at least three points and a first image of the marker located in a first portion is captured and stored and a second image of the marker in a second position that is different than the first position is stored. Also, translation and/or rotation of the component in three-dimensional space between the first position and the second position is calculated.

Claims

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.

2. The method according to claim 1, wherein the at least three points are arranged on corners of a triangle.

3. The method according to claim 2, wherein the triangle is an isosceles triangle.

4. The method according to claim 2, wherein the triangle is an equilateral triangle.

5. The method according to claim 1, wherein the sensor of the camera is a CCD sensor.

6. The method according to claim 1, wherein the marker has a rigid carrier.

7. The method according to claim 6, wherein the rigid carrier is attached to the component.

8. A measurement system for capturing and measuring translation and rotation of a component of a motor vehicle moving relative to a reference system, the measurement system configured to: provide 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; provide the 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; align the camera with the at least three points; capture 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; capture 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 calculate a translation and/or rotation of the component in three-dimensional space between the first and the second position of the component.

9. The system according to claim 8, wherein the marker has a carrier configured to be resistant to vibrations.

10. The system according to claim 8, wherein the at least one of the at least three points are configured as a circular disk.

11. The system according to claim 8, wherein the at least the three points are arranged on corners of a triangle selected from an isosceles triangle or an equilateral triangle.

12. The system according to claim 8, wherein the marker has a carrier and an upper side of the carrier is planar.

13. The system according to claim 8, wherein the at least three points are of a first color and a background of the upper side of the marker is of a second color different than the first color.

14. The system according to claim 8, wherein a transition from one point of the at least three points to a background of the upper side is discontinuous.

15. The system according to claim 8, wherein the evaluation unit includes a computer with a program for image capturing and evaluation, a memory for storing the geometry of the upper side of the marker and the at least three points of the marker.

16. One or more non-transitory computer-readable media storing processor-executable instructions that, when executed by at least one processor, cause the at least one processor to: a) providing a marker on a 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 a reference system which translation and/or rotation of a 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.

17. The one or more non-transitory computer-readable media of claim 16, wherein the at least three points are arranged on corners of a triangle.

18. The one or more non-transitory computer-readable media of claim 16, wherein the triangle is an isosceles triangle or an equilateral triangle.

19. The one or more non-transitory computer-readable media of claim 16, wherein the sensor of the camera is a CCD sensor.

20. The one or more non-transitory computer-readable media of claim 16, wherein the marker has a rigid carrier and is attached to the component.

Description

DRAWINGS

(1) In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:

(2) FIG. 1 shows a perspective illustration of a measurement system and a component in a first position, to which a marker is attached, and a second position of the marker without the component, according to the teachings of the present disclosure;

(3) FIG. 2 shows a plan view of a first configuration of a marker of type A according to the teachings of the present disclosure;

(4) FIG. 3 shows a plan view of a second configuration of the marker of type A according to the teachings of the present disclosure;

(5) FIG. 4 shows a plan view of a third configuration of the marker of type A according to the teachings of the present disclosure;

(6) FIG. 5 shows a plan view of a fourth configuration of the marker of type A according to the teachings of the present disclosure;

(7) FIG. 6 shows a geometric illustration of relevant dimensions according to the teachings of the present disclosure;

(8) FIG. 7 shows a geometric illustration of different views in parallel projection of the marker of type An according to the teachings of the present disclosure;

(9) FIG. 8 shows a simplified geometric illustration of a beam path according to the teachings of the present disclosure;

(10) FIG. 9 shows a plan view of a first configuration of a marker of type B according to the teachings of the present disclosure;

(11) FIG. 10 shows a plan view of a second configuration of the marker of type B according to the teachings of the present disclosure;

(12) FIG. 11 shows a plan view of a third configuration of the marker of type B according to the teachings of the present disclosure;

(13) FIG. 12 shows a plan view of a fourth configuration of the marker of type B according to the teachings of the present disclosure;

(14) FIG. 13 shows a geometric illustration of relevant dimensions similar to FIG. 6 according to the teachings of the present disclosure;

(15) FIG. 14 shows a geometric illustration of different views in parallel projection of the marker of type B similar to FIG. 7 according to the teachings of the present disclosure; and

(16) FIGS. 15a-15d show geometric illustrations for explaining a calculation according to the teachings of the present disclosure.

(17) The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION

(18) The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

(19) FIG. 1 shows a component 20, illustrated here only schematically, in a first position, to which a marker 22 is removably attached over as large an area as possible using, for example, hot-melt adhesive bonding. The marker 22 has a square carrier 24 having an upper side 26. The carrier 24 is produced to be rigid but also resistant to vibrations, preferably made from a layered material, such as aluminum-foam-aluminum. In some variations of the present disclosure, the carrier 24 does not become deformed by the connection to the component 20. That is, during the movements of the component 20, the carrier 24 moves rigidly with the component 20 and does not exhibit natural oscillations.

(20) The same marker 22 is illustrated in a second position in FIG. 1, in which it is in front of the first position (i.e., closer to a camera 30). The component 20 is not illustrated in the second position.

(21) A measurement system 28, which in the present case is arranged in a spatially fixed reference system, has a camera 30 and an evaluation unit 32. The camera 30 has a sensor and an optical axis 34 and is directed at a centerpoint 36, also referred to as evaluation point, of the marker 22. The evaluation unit 32 has image recognition and stores the geometric data of the marker 22 that is being used. The geometric data include the three corner points of a triangle situated on the marker 22, with the corner points being the points A, B and C shown in FIG. 1, which are to be captured.

(22) Referring to FIGS. 2 to 5, possible variations of a “type A” marker 22 according to the teachings of the present disclosure are shown. The hatching signifies a completely black color, while everything that has not been hatched is white, with the exception of the thick black lines in FIGS. 3 to 5. The transition between black and white in each case is desirably abrupt. FIGS. 2 to 5 also show a mark 38 for the purposes of alignment, which can be desirable. The position of the mark 38 on the marker 22 is likewise stored in the evaluation unit 32.

(23) Regarding the type A marker 22, the three points A, B and C are defined as corner points of an equilateral triangle having the side length “l.” The corner points are identical, that is to say a 120° rotation about the centerpoint P (FIG. 6) of the circumcircle of the triangle produces the same triangle, that is to say a rotational symmetry of 120°. For the purposes of alignment, in some variations of the present disclosure an additional mark 38 is provided. In FIGS. 2, 4 and 5, the mark 38 is a small circular area, and in FIG. 3 the mark 38 is a small bar. FIGS. 2 to 5 also show alternatives of a different design of the points A, B and C. In FIG. 2, the points A, B and C are represented by the corner points of the triangle having the white area, in FIG. 3 the points A, B and C are represented by congruent black circular areas on the corner points of the triangle, in FIG. 4 the points A, B and C are represented by the corner points of a triangle having a black boundary line, and in FIG. 5 the points A, B and C are represented by white gaps in a black circular ring. In FIG. 2, the background is black, and in FIGS. 3 to 5 the background is white in each case. The mark 38 for FIG. 2 is white, otherwise the mark 38 is black. The mark 38 also exhibits a contrast and an abrupt transition with respect to the background on the upper side 26. As used herein, the phrase “abrupt transition” refers to a change from one color to another color, e.g., black to white or white to black, that can be represented by a mathematical step function. In some variations of the present disclosure, the mark 38 also exhibits as great or high as possible color contrast and an abrupt transition with respect to the background on the upper side 26. The dimensions illustrated in FIG. 6 are used for a calculation and it is possible to choose different dimensions, although different dimensions typically require different algorithms.

(24) FIGS. 6, 7 and 8 serve for explaining the following description for transformations used with the following dimensions defined as:

(25) Side length of the equilateral triangle: l=a=b=c

(26) Focal length of the objective lens of the camera 30: f.sub.Obj

(27) Distance of the camera 30 from the marker 22: D′

(28) Active sensor width (CCD chip of the camera): w.sub.s

(29) Active sensor height (CCD chip of the camera): h.sub.s

(30) And dimensions of the marker 22 being:

(31) h=height of the triangle:

(32) $h=\sqrt{\frac{3}{4}}l$

(33) r.sub.cc=radius of the circumcircle of the triangle:

(34) $r_{cc}=\sqrt{\frac{3}{9}}l$

(35) Measured coordinates are: A.sub.0 (A.sub.0x|A.sub.0y), B.sub.0 (B.sub.0x|B.sub.0y), C.sub.0 (C.sub.0x|C.sub.0y), where A.sub.0 is the coordinate opposite the base of the triangle, defined by the additional mark 38. That is, the additional mark 38 is positioned proximate the base of the triangle in FIGS. 3-5 and A.sub.0 is the coordinate opposite the base of the triangle.

(36) For the nomenclature used, the following example is given: “A.sub.0y”=y.sub.s-coordinate of A.sub.0 and “A.sub.0x)”=x.sub.s-coordinate of A.sub.0 in the plane of the image sensor (sensor coordinate system).

(37) These values (i.e., A.sub.0, B.sub.0, C.sub.0) represent the positions of the three points captured in the plane of the sensor. If the measured coordinates were initially captured in image points (“pixels”) of the sensor image, their actual positions that they occupy in the plane of the sensor of the camera 30 can be obtained by setting the height of the image produced and its width to the active sensor height and sensor width h.sub.s and w.sub.s, respectively. It is possible to use correction factors to correct the image curvature and other lens aberrations of the objective lens of the camera 30.

(38) The side lengths of the triangle in the plane of the sensor are:
a.sub.0=B.sub.0C.sub.0=√{square root over ((C.sub.0x−B.sub.0x).sup.2+(C.sub.0y−B.sub.0y).sup.2)}
b.sub.0=A.sub.0C.sub.0=√{square root over ((C.sub.0x−A.sub.0x).sup.2+(C.sub.0y−A.sub.0y).sup.2)}
c.sub.0=A.sub.0B.sub.0=√{square root over ((B.sub.0x−A.sub.0x).sup.2+(B.sub.0y−A.sub.0y).sup.2)}

(39) And the midpoints of the triangle sides are then ascertained by:

(40) $M_{a0x}=\frac{\left(C_{0x}+B_{0x}\right)}{2};M_{a0y}=\frac{\left(C_{0y}+B_{0y}\right)}{2}{M}_{b0x}=\frac{\left(C_{0x}+A_{0x}\right)}{2};M_{b0y}=\frac{\left(C_{0y}+A_{0y}\right)}{2}{M}_{c0x}=\frac{\left(A_{0x}+B_{0x}\right)}{2};M_{c0y}=\frac{\left(A_{0y}+B_{0y}\right)}{2}$

(41) Also, the centerpoint P of the circumcircle of the triangle is calculated by the following procedure.

(42) In the undeformed triangle, that is to say when the optical axis 34 of the camera 30 extends at a right angle to the surface of the marker 22, P is the centerpoint of a circumcircle of the triangle, defined by the point of intersection between two perpendicular bisectors, which are at the same time lines bisecting an angle. The two perpendicular bisectors can also be described as straight lines that each connect a corner point to the midpoint on the opposite side where:

(43) P.sub.0=point of intersection of the straight lines through B.sub.0M.sub.b0 and C.sub.0M.sub.c0 and:

(44) $P_{0x}=\frac{\begin{array}{c}\left(M_{c0x}-C_{0x}\right).Math.\left(M_{b0x}.Math.B_{0y}-B_{0x}.Math.M_{b0y}\right)-\\ \left(M_{b0x}-B_{0x}\right).Math.\left(M_{c0x}.Math.C_{0y}-C_{0x}.Math.M_{c0y}\right)\end{array}}{\left(M_{c0y}-C_{0y}\right).Math.\left(M_{b0x}-B_{0x}\right)-\left(M_{b0y}-B_{0y}\right).Math.\left(M_{c0x}-C_{0x}\right)}{P}_{0y}=\frac{\begin{array}{c}\left(B_{0y}-M_{b0y}\right).Math.\left(M_{b0x}.Math.C_{0y}-C_{0x}.Math.M_{c0y}\right)-\\ \left(C_{0y}-M_{c0y}\right).Math.\left(M_{b0x}.Math.B_{0y}-B_{0x}.Math.M_{b0y}\right)\end{array}}{\left(M_{c0y}-C_{0y}\right).Math.\left(M_{b0x}-B_{0x}\right)-\left(M_{b0y}-B_{0y}\right).Math.\left(M_{c0x}-C_{0x}\right)}$

(45) Point P.sub.0 is the centerpoint 36 of an ellipse that is the projection of the circumcircle of the triangle. On account of the rotational symmetry of the ellipse, further points of the ellipse can be found as follows:
D.sub.0x=P.sub.0x−(A.sub.0x−P.sub.0x);D.sub.0y=P.sub.0y−(A.sub.0y−P.sub.0y)
E.sub.0x=P.sub.0x−(B.sub.0x−P.sub.0x);E.sub.0y=P.sub.0y−(B.sub.0y−P.sub.0y)
F.sub.0x=P.sub.0x−(C.sub.0x−P.sub.0x);F.sub.0y=P.sub.0y−(C.sub.0y−P.sub.0y)

(46) It should be understood that these parameters of the ellipse are desired to ascertain the distance of the marker 22 from the sensor and are calculated as follows.

(47) Algorithm for Ascertaining the Translational Movement and the Rotation of the Marker 22:

(48) Calculation of the ellipse, projected image of the circumcircle as shown in FIG. 7 is generally described by the following formula:
c.sub.ax.sup.2+c.sub.bxy+c.sub.cy.sup.2+c.sub.dx+c.sub.ey+c.sub.f=0

(49) It is possible here to freely select one of the coefficients c, for example c.sub.a=1, leaving 5 unknowns (e.g. c.sub.b . . . c.sub.f) which can be ascertained by way of five linear equations, with each of said linear equations using the x- and y-coordinates of one of the 5 points on the circumcircle of the ellipse. This system of linear equations can be solved using conventional methods, provided the three corner points of the triangle are detected and do not lie on a straight line.

(50) Using the ascertained coefficients c.sub.a . . . c.sub.f, an axis transformation can be used to determine the semi-major axis of the ellipse. To this end, the following formula can be used:

(51) $\left(xy\right)\left(\begin{array}{cc}{c}_a& c_{b/2}\\ c_{b/2}& c_c\end{array}\right)\left(\begin{array}{c}x\\ y\end{array}\right)+\left(c_d{c}_e\right)\left(\begin{array}{c}x\\ y\end{array}\right)+c_f=0$

(52) or in simplified form:
v.sup.TAv+u.sup.Tv+c.sub.f=0

(53) This can be converted into the following form:
v′.sup.TDv′+u.sup.TTv′+c.sub.f=0

(54) where:

(55) D=matrix A that has been brought into the diagonal form:

(56) $\det A_{\lambda }=.Math.\begin{array}{cc}\left(c_a-\lambda \right)& c_{b/2}\\ c_{b/2}& \left(c_c-\lambda \right)\end{array}.Math.\stackrel{!}{=}0.Math.D=\left(\begin{array}{cc}{\lambda }_1& 0\\ 0& {\lambda }_2\end{array}\right);$${\lambda }_{1,2}\text{:}\mathrm{eigen}\mathrm{values}\mathrm{of}A$

(57) T=transformation matrix (rotation of the ellipse):

(58) $T=\left(\begin{array}{cc}{t}_{11}& t_{12}\\ t_{21}& t_{22}\end{array}\right)$$\mathrm{where}{t}_1=\left(\begin{array}{c}{t}_{11}\\ t_{21}\end{array}\right)\mathrm{and}{t}_2=\left(\begin{array}{c}{t}_{12}\\ t_{22}\end{array}\right):\mathrm{And}$$\mathrm{normalized}\mathrm{eigenvectos}\mathrm{with}\mathrm{respect}\mathrm{to}\mathrm{the}\mathrm{eigen}\mathrm{values}{\lambda }_{1,2}$$\mathrm{such}\mathrm{that}\det T=1\left(\mathrm{rotation}\mathrm{matrix}\right)$

(59) The calculation of the stated terms results in the description of an ellipse of the same size, but rotated into a position with the semi-major axis parallel to the coordinate system:
λ.sub.1x.sup.2+λ.sub.2y.sup.2+(c.sub.dt.sub.11+c.sub.et.sub.21)x+(c.sub.dt.sub.12+c.sub.et.sub.22)y+c.sub.f=0

(60) which can be converted into:

(61) ${{\lambda }_1\left(x+\frac{p_x}{2}\right)}^2+{{\lambda }_2\left(y+\frac{p_y}{2}\right)}^2+q=0(*)$

(62) where:

(63) $p_x=\frac{\left(c_d{t}_{11}+c_e{t}_{21}\right)}{{\lambda }_1};p_y=\frac{\left(c_d{t}_{12}+c_e{t}_{22}\right)}{{\lambda }_2};$$q=-{{\lambda }_1\left(\frac{p_x}{2}\right)}^2-{{\lambda }_2\left(\frac{p_y}{2}\right)}^2+c_f$

(64) The coordinates of the centerpoint 36 of the rotated ellipse are:

(65) 0$x_C=-\frac{p_x}{2}\mathrm{and}{y}_c=-\frac{p_y}{2}$

(66) Setting y=y.sub.C and x=x.sub.C in gives the points of intersection of the straight lines, determined by the major and the minor axis, with the ellipse:

(67) $x_{1,2}=-\frac{p_x}{2}\pm \sqrt{-\frac{q}{{\lambda }_1}};y_{1,2}=-\frac{p_y}{2}\pm \sqrt{-\frac{q}{{\lambda }_2}}$

(68) Consequently, the lengths of the semi-axes are:

(69) $r_1=\sqrt{-\frac{q}{{\lambda }_1}};r_2=\sqrt{-\frac{q}{{\lambda }_2}}$

(70) Here, the larger value for the semi-major axis r.sub.a applies:
r.sub.a=max(r.sub.1;r.sub.2)

(71) The value thus calculated is effected specifically for the marker of type A and will be used later to determine the translation.

(72) Marker 22 of Type B:

(73) Regarding the type B marker 22, FIGS. 9 to 12 show markers 22, which are configured similarly to the markers 22 of FIGS. 2 to 5, which have already been described, but in this case they have a different geometry of the points and possibly of the mark. Reference is made to that description, and therefore only the differences will be explained. One difference lies in the fact that the points A, B, C no longer rely on the corner points of an equilateral triangle, but of an isosceles right triangle. Furthermore, the points are now no longer congruent. Rather, the point A in FIG. 9 is illustrated by way of a considerably larger circular area than the two other points B and C, and a mark is therefore not desired, but it may be advantageous, as shown in FIG. 11.

(74) The calculation for the sensor of type B will now be explained.

(75) Sensors of type B permit a considerably simpler algorithm for the calculation of the ellipse of the circumcircle because the points A, B, C define particular points on the ellipse (conjugated diameters):

(76) For this form of the present disclosure, the points “A”, “B” and “C” are the corner points of an isosceles right triangle. Consequently, they lie on three corner points of a square. The point “A” is the vertex of the right angle. “A” can for example be specified by a particular geometry of said point, a different size, a different form, a different color or by an additional mark and can thus be recognized in the evaluation unit 32. The dimensions stated in FIG. 13 are used for the calculation. Other geometries are possible, however they may need different algorithms than described below.

(77) Algorithm for Calculating the Translational Movement and the Rotation in Space of the Marker 22 of Type B:

(78) FIGS. 8 and 14 show the variables used in the algorithm for the calculation with the following dimensions defined as:

(79) Side length of the isosceles triangle: I=b=c;

(80) Focal length of the objective lens of the camera 30: f.sub.Obj;

(81) Distance of the camera 30 from the marker 22: D′;

(82) Active sensor width (CCD chip): w.sub.s; and

(83) Active sensor height (CCD chip): h.sub.s;

(84) Dimensions of the marker 22 are defined as:

(85) h=height of the triangle;

(86) And the parameters of the marker 22 are defined as:

(87) a=length of the base of the triangle:

(88) a=l√{square root over (2)}; and

(89) h=height of the isosceles triangle of the marker 22 and r.sub.cc=radius of the circumcircle of the triangle:
h=r.sub.cc=½√{square root over (2)};

(90) Measured coordinates (in the plane of the sensor) are: A.sub.0 (A.sub.0x|A.sub.0y), B.sub.0 (B.sub.0x|B.sub.0y), C.sub.0 (C.sub.0x|C.sub.0y), where A.sub.0 is the vertex of the right angle.

(91) For the nomenclature used, the following example is given: “A.sub.0y”=y.sub.s-coordinate and “A.sub.0x”=x.sub.s-coordinate of A.sub.0 in the camera image (sensor plane of the camera 30).

(92) These values (i.e., measured coordinates) represent the positions of the three points captured in the plane of the sensor. If the measured coordinates were initially captured in image points (“pixels”) of the sensor image, their actual positions that they occupy in the plane of the sensor of the camera 30 can be obtained by setting the height of the image produced and its width to the active sensor height and sensor width h.sub.s and w.sub.s, respectively. It is possible to use correction factors to correct the image curvature and other lens aberrations of the objective lens of the camera 30.

(93) Capturing of Point P, the Centerpoint:

(94) P.sub.0 is the midpoint between B.sub.0 and C.sub.0:

(95) $P_{0x}=\frac{\left(C_{0x}+B_{0x}\right)}{2};P_{0y}=\frac{\left(C_{0y}+B_{0y}\right)}{2}$
and the side lengths of the triangle in the image of the camera 30 (plane of the sensor) are:
a.sub.0=B.sub.0C.sub.0=√{square root over ((C.sub.0x−B.sub.0x).sup.2+(C.sub.0y−B.sub.0y).sup.2)}
b=A.sub.0C.sub.0=√{square root over ((C.sub.0x−A.sub.0x).sup.2+(C.sub.0y−A.sub.0y).sup.2)}
c.sub.0=A.sub.0B.sub.0=√{square root over ((B.sub.0x−A.sub.0x).sup.2+(B.sub.0y−A.sub.0y).sup.2)}

(96) The circumcircle of the triangle, which is identical to the circumcircle of the rectangle formed by the addition of a congruent triangle, appears as an ellipse having the centerpoint P.sub.0 in the sensor plane of the camera 30, wherein a parallel projection is assumed. The point A is the end point of the radius “h” of said circumcircle, the point D is the exact opposite point on the circumcircle, and the points B and C are end points of a diameter at a right angle to h. Consequently, the projected points A.sub.0, B.sub.0, C.sub.0, D.sub.0 (FIG. 14) form two conjugated diameters of the ellipse. It should be understood that the parameters of this ellipse are desired to determine the distance of the marker 22 from the sensor and are ascertained, based on a Rytz's construction, as shown in FIG. 15, as follows:

(97) Circle around P.sub.0 having the radius r.sub.A(=½B.sub.0C.sub.0);

(98) Perpendicular to B.sub.0C.sub.0, intersection with the circle=>Q;

(99) Line through Q and A.sub.0=>g;

(100) Midpoint between Q and A.sub.0=>R;

(101) Circle around the center R having the radius r.sub.B(=RP.sub.0);

(102) Intersection of this circle and g=>S and T;

(103) The distances QS and QT represent the lengths of the semi-axes of the ellipse; and

(104) The longer one (here: QT) represents the semi-major axis r.sub.a, and the shorter one represents the semi-minor axis.

(105) Accordingly, lines through P.sub.0 S and P.sub.0T represent the directions of the semi-axes of the ellipse with the straight line through P.sub.0 and the point S or T having the greater distance from Q (here: T) representing the direction of the semi-major axis and the straight line through P.sub.0 and the point S or T having the shorter distance from Q (here: S) representing the direction of the semi-minor axis (at a right angle with respect to the semi-major axis, proof by what is referred to as Thales's circle).

(106) These calculations are significantly simpler than calculations for the marker 22 of type A (equilateral triangle) because no axis transformation is desired or needed to determine the semi-axes and thus the increased time spent for solving a set of linear equations is dispensed with.

(107) Using the coordinates in the sensor plane (origin in the upper left corner, +x to the right, +y down), the following is calculated:

(108) $P_{0x}=\frac{B_{0x}+C_{0x}}{2};P_{0y}=\frac{B_{0y}+C_{0y}}{2}{Q}_x=P_{0x}-\left(B_{0y}-P_{0y}\right);Q_y=P_{0y}+\left(B_{0x}-P_{0x}\right)$

(109) It should be understood that this calculation is a rotation about 90° in the mathematically positive sense in the given coordinate system, in the image consequently in the direction of clockwise rotation. Also:

(110) $R_x=\frac{A_{0x}+Q_x}{2};R_y=\frac{A_{0y}+Q_y}{2};$$r_B=\sqrt{{\left(R_x-P_{0x}\right)}^2+{\left(R_y-P_{0y}\right)}^2};$$S_x=R_x-r_B*\frac{Q_x-A_x}{\sqrt{{\left(Q_x-A_x\right)}^2+{\left(Q_y-A_y\right)}^2}};$$S_y=R_y-r_B*\frac{Q_y-A_y}{\sqrt{{\left(Q_x-A_x\right)}^2+{\left(Q_y-A_y\right)}^2}};\mathrm{and}$$T_x=R_x+r_B*\frac{Q_x-A_x}{\sqrt{{\left(Q_x-A_x\right)}^2+{\left(Q_y-A_y\right)}^2}};$$T_y=R_y+r_B*\frac{Q_y-A_y}{\sqrt{{\left(Q_x-A_x\right)}^2+{\left(Q_y-A_y\right)}^2}}$

(111) The semi-axes are:
r.sub.S=QS=√{square root over ((Q.sub.x−S.sub.x).sup.2+(Q.sub.y−S.sub.y).sup.2)};r.sub.T=QT=√{square root over ((Q.sub.x−T.sub.x).sup.2+(Q.sub.y−T.sub.y).sup.2)}

(112) where, the semi-major axis r.sub.a is:
r.sub.a=max (r.sub.s;r.sub.T)
Calculation of the Distance of the Marker 22 (Type A and B) from the Sensor:

(113) If a circle is projected onto a plane to form an ellipse, the semi-major axis keeps the length of the radius of the circle (for parallel projection). Since the ellipse was formed by rotating the circumcircle of the triangle of the marker 22, the semi-major axis of the ellipse represents the radius of the circumcircle. Therefore, the comparison of the real size of the circle to the length of the semi-axis can be used to determine the distance of the marker 22 from the sensor (in the direction of the z-coordinate) or the main plane of the objective lens, because a ratio ≠1 is caused by the (non-parallel) projection, specifically by an entocentric lens of the sensor.

(114) The aspect ratio when using a thin lens (see FIG. 8) is defined as:

(115) $\frac{r_a}{r_{cc}}=\frac{t^{\prime }}{t}=m=\frac{D^{\prime }}{D}=\frac{1}{\frac{D}{f_{\mathrm{Obj}}}-1}.Math.D=\left(\frac{1}{m}+1\right)f_{\mathrm{Obj}}$

(116) The position of the target and of a coordinate system that is fixedly connected thereto relative to the sensor or reference coordinate system can be produced by way of an imaginary shift from an originally congruent location of both coordinate systems to the considered position of the target. This shift can be made up of three translations (one in each case in the direction of the three axes of the reference system) and three successively performed rotations about the axes of the target coordinate system in its respective location that has been brought about by the prior shifts, where attention is paid to the sequence of the different rotations (Euler angle). If the locations of the target coordinate system are marked using prime symbols as per the individual imaginary shifts, specifically a single prime after the translations, a double prime after the first rotation, and a triple prime after the second rotation, then, as shown in FIG. 14:

(117) Rotation about the z.sub.t′-axis:

(118) $\Psi ={\tan }^{-1}\left(\frac{C_{0y}-B_{0y}}{C_{0x}-B_{0x}}\right)$

(119) Rotation about the y.sub.t″-axis:

(120) $\Theta ={\cos }^{-1}\left(\frac{a_0}{m.Math.a}\right)$

(121) Rotation about the x.sub.t′″-axis:

(122) ${\beta }_0={\cos }^{-1}\left(\frac{a_0^2+c_0^2-b_0^2}{2.Math.a_0.Math.c_0}\right);\left[\mathrm{cosine}\mathrm{theorem}\right]$$s_0=c_0.Math.\cos \left({\beta }_0\right);h_1=\frac{s_0-\frac{a_0}{2}}{\sin \left(\Theta \right)}\varphi ={\sin }^{-1}\left(\frac{h_1}{m.Math.h}\right)$

(123) The translation of the centerpoint is:

(124) 0$x=\frac{P_{0x}}{m};y=\frac{P_{0y}}{m};z=D_{ref}-D$

(125) where D.sub.ref is the distance of the sensor from the zero point of the reference system.

(126) This describes the position of the marker 22 and its translation and rotation with respect to the sensor.

(127) The system can be used not only to measure the translation and rotation of a component moving relative to a reference system (even though this is a desired use), but also to ascertain the position with respect to the translation and rotation of a component relative to a reference position (for example target at the center of the image, target surface perpendicular to the optical axis of the camera) with just a single image, even if the object does not move at all but is merely positioned differently relative to the reference position.

(128) Preferably, the calculation of a movement is also always performed such that first, the position of the target with reference to the reference position is calculated for each image and then the movement from one image to the other is described by way of comparing the positions (difference of the values of two images).

(129) The point P or the centerpoint 36 is the measurement point or evaluation point, that is to say the point of the target (and thus also of the component), for which the movement of the target (and of the object) is calculated and evaluated.

(130) The point P or the centerpoint 36 is preferably identical to the centerpoint of the circumcircle around the three submarker points, also the centerpoint of the triangle formed by the three points only in the case of the target of type A.

(131) The method for capturing and measuring the translation and the rotation of a component 20 moving relative to a reference system includes:

(132) a) providing a marker 22 on the component 20, wherein the marker 22 has on an upper side 26 at least three points A, B, C, which do not lie on a straight line,

(133) b) providing a measurement system 28 having a camera 30, which is arranged in the reference system, and having an evaluation unit 32, in which the geometry of the upper side 26 and thus in particular of the three points A, B, C is stored,

(134) c) aligning the camera 30 with the three points A, B, C, in particular a centerpoint P of the three points A, B, C,

(135) d) capturing a first image of the marker 22 and of the component 20, which are located in a first position, and determining the location of the three points A, B, C in the first image, wherein the x- and y-coordinates of the three points A, B, C and possibly the alignment thereof in the image plane of the first image are determined,

(136) e) calculating a first position of the marker in three-dimensional space with respect to translation and rotation relative to a reference position at the time point at which the first image is created,

(137) f) capturing a second image of the marker 22 and of the component 20, which are located in a second position, which differs from the first position, and determining the location of the three points A, B, C in the second image, wherein the x- and y-coordinates of the three points A, B, C and possibly the alignment thereof in the image plane of the second image are determined,

(138) g) calculating a second position of the marker in three-dimensional space with respect to translation and rotation relative to a reference position at the time point at which the second image is created,

(139) h) comparing the x- and y-coordinates and the alignment of the three points A, B, C in the two images and calculating the translation and rotation of the component 20 in three-dimensional space between the first and the second position of the component 20.

(140) When calculating the translation and/or rotation of the component 20, preferably a comparison is performed of the x- and y-coordinates and the alignment of the three points (A, B, C) in the two images.

(141) Unless otherwise expressly indicated herein, all numerical values indicating mechanical/thermal properties, compositional percentages, dimensions and/or tolerances, or other characteristics are to be understood as modified by the word “about” or “approximately” in describing the scope of the present disclosure. This modification is desired for various reasons including industrial practice, material, manufacturing, and assembly tolerances, and testing capability.

(142) As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”

(143) The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.