WO2018068775A1

WO2018068775A1 - Method and system for determining the defective surface of at least one fault location on at least one functional surface of a component or test piece

Info

Publication number: WO2018068775A1
Application number: PCT/DE2017/000170
Authority: WO
Inventors: Peter Bannwitz; Jan-Philipp Köhler
Original assignee: INPRO Innovationsgesellschaft für fortgeschrittene Produktionssysteme in der Fahrzeugindustrie mbH
Priority date: 2016-10-15
Filing date: 2017-06-14
Publication date: 2018-04-19
Also published as: DE102016012371A1

Abstract

The invention relates to the determining of the defective surface (DF) of at least one fault location (7) on at least one functional surface Z (x, y) of a component or test piece (1), comprising the following method steps: sequentially illuminating the component or test piece (1) in at least one measurement region (2) of the functional surface Z (x, y) from at least four different positions (a, b, c, d) with at least one light source (3) that is defined in terms of the intensity, direction and position of radiation; creating a respective different actual image capture (raw image) (R _a, R _b, R _c, R _d) of the functional surface Z (x, y) in the at least one measurement region (2) using at least one camera (4) in a known position and connected to a control and computer system (5); calculating the x- or y-slope images (N _x, N _y) of the functional surface Z (x, y) for the four actual image captures (raw images) (R _a, R _b, R _e, R _d) on the basis of the shape-from-shading (SFS) method using the control and computer system (5); creating a dark field image capture (D) of the functional surface Z (x, y) in the measurement region (2) during a dark field illumination; and determining the actual defective surface (DF) of the at least one fault location (7) in the at least one measurement region (2) of the functional surface Z (x, y) of the component or test piece (1) from the x- or y-slope image calculations (N _x, N _y) of the functional surface Z (x, y) and the data of the dark field image capture (D) by means of the control and computer system (5).

Description

Method and system for determining the defect surface of at least one defect on at least one functional surface of a component or test specimen

The invention relates to a method and a system for determining the defect surface of at least one defect on at least one functional surface of a component or specimen.

The testing of functional surfaces for damage such as e.g. Pores, scratches, dents, etc. are usually also in largely fully automated manufacturing processes usually by a personal visual inspection according to specified test specifications at the end of the manufacturing process. In this case, the person to be tested must be in good order (i.O.) or not in order (n.i.O.) in the production cycle about the quality. decide on a component.

Since, in particular in the automotive industry, the quality specifications prescribed by the test regulations are in the range of tenths of millimeters, such as, for example, given error sizes i.O. <500 μm and n.i.O. > 500 μm, the human eye is only able to dissolve and reproduce such a size range unreliably. In addition, the extensive test specifications such. extremely complex and varied geometry of the surfaces with different evaluation ranges with respect to error sizes and types of overtaxing the visually inspecting person. Decisions on i.O.- or n.i.O. Judgments are therefore made on the basis of estimated error magnitudes, subjective perception, and experience, so that irregular slip, ie, the examiner does not test accurately enough, and / or pseudo, ie, the examiner examines too accurately in manufacturing , which results in delays in the production process and additional costs.

Optical methods, in particular laser-based, generally require a relatively high calibration effort. A special camera - based optical method is the stereometry, in which the surface of a component or specimen to be examined is recorded from slightly different angles and from the evaluation of the minor stereoscopic deviations are calculated the structures of the surface of the component or specimen.

Changes in the inclination angle course or even flat structures such as low depressions and / or slight inclinations with low inclination can be determined by the method of shape-from-shading (see in particular X. Jiang, H. Bunke, Three-dimensional Computer Vision, Springer Verlag, 1997 Berlin ). In this case, small changes in the reflected light intensity are evaluated in order to close the known inclination of the reflective areas with a known geometric arrangement between the camera, component or specimen and light source.

From DE 10 2004 038 761 B4 a method for camera-based inspection of objects, in particular of castings and forgings, on the basis of the method of shape-from-shading is known, wherein the object to be tested is illuminated by at least one light source. In this case, at least one part of the part of the object surface illuminated by the light source is detected by means of at least one camera and the image data resulting therefrom are subjected to image processing. An evaluation with respect to the entire object surface does not take place here, but for partial sections, image regions (ROI, regions of interest) are selected within the image data and fed to a further processing in which the method of shape-from-shading (SfS) is applied to the image regions. The determination of an approximately real geometry of the defect surface of defects of the examined object surface is not possible in this known method.

Furthermore, a device for detecting defects of a surface of an object is known to be known from DE 203170 95 U1, in which a light source for illuminating the object is provided with an illumination beam incident on the object at an angle of incidence to the surface and a light sensor from which a beam reflected from the surface of the object towards the exposure beam is detected, which is reflected at a projection angle to the surface of the object from the latter. In this case, the angle of reflection is equal to the angle of incidence in order to obtain image data which are to be evaluated by an evaluation unit in order to detect possible errors. A determination of the real area of defects of the inspected object surface is also not provided in this known method and is not considered. The present invention is therefore based on the object of providing a method and a plant of the type mentioned above, with which or a determination of the real geometric features of at least one defect on at least one functional surface of a component or Prüfköpers is possible.

This object is achieved according to the invention by a method for determining the defect surface of at least one defect on at least one functional surface of a component or test body, comprising the method steps:

the component or the specimen is sequentially illuminated from at least four different positions in at least one measuring range of the functional surface with at least one light source defined in terms of radiation intensity, direction and position,

from the functional surface of the component or test specimen, a real image image (raw image) of a functional surface in the measuring region, which is illuminated from different directions, is created with at least one camera connected to a control and computer system,

from the control and computer system, the inclination patterns in the x- or y-derivative of the functional surface are calculated on the basis of the shape-from-shading method for the four differently illuminated real image recordings (raw images),

- In addition to the raw images for tilt image calculation during dark field illumination of the functional surface of the component or specimen is still created a dark field image recording of the functional surface in the measuring range, and

From the two inclination image calculations of the functional surface and the information of the dark field image acquisition, the real defect area of the at least one defect in the measurement area of the functional surface of the component or specimen is determined by means of the control and computer system.

Preferably, the calculated inclination images are binarized, and the at least one defect on the at least one functional surface is detected from the binarized inclination images, wherein for a defect size in the range of tenths of millimeters, its geometry in the binarized inclination images approximately matches the real defect surface of the defect the case, however, that the size of Subareas of the defect lies in a larger area, these sub-areas, which are reproduced only incompletely in the inclination images, are binarized via the dark field image acquisition of the functional surface and combined with the binarization of the inclination images. From the combined binarization of the tilt images and the dark field image acquisition, the real geometry of the defect surface of the defect of the functional surface is then determined approximately accurately.

Preferably, four individual, in series reflectors are used as light sources, of which the functional surface is illuminated for at least one image acquisition series with four real image recordings (raw images) successively each with a defined exposure time.

As dark field lighting LED strips, preferably four LED strips, used, which are all connected together.

Preferably, three image acquisition series with four real image recordings (raw images) are created by the functional surface by means of a CCD camera, wherein the functional surface in each of the three image acquisition series is illuminated successively by the series-connected reflectors with a defined exposure time.

For inhomogeneous reflection properties, i. In a little to highly reflective functional surface of the component or Prüflcörpers the three image acquisition series with the four real images (raw images) with different exposure times of the four reflectors are created by the component or the test specimen in at least one measurement range of the functional surface with the Reflectors defined in terms of radiation intensity, direction and position is illuminated sequentially from the four different positions.

Thus, the first image acquisition series with real first four images (raw images) with an exposure time of 0.01 ms, the second image acquisition series with real four other images with an exposure time of 0.025 ms, the third image acquisition series with another four real Imaging with an exposure time of 0.05 ms, and after the first, the second and the third image acquisition series, respectively, a dark field image recording for the respective determination of the defect surface of the defect can be created.

Instead of the dark field illumination, bright field illumination can be generated, during which a bright field image acquisition of the at least one functional surface in the at least one measurement range is created. Subsequently, from the inclination image calculations of the functional surface and the information of the bright field image acquisition, the real defect surface of the at least one defect in the at least one measurement region of the functional surface of the component or specimen is determined by means of the control and computer system.

After the inclination images have been calculated from the real image recordings (raw images) of the at least one functional surface in the at least one measuring region, a grayscale equalization can take place via a Savitzky-Golay filter.

Preferably, the at least one measuring range of the functional surface is subdivided into sectors, and a separate parameterization is carried out per inclination image recording and per dark field image recording or per bright field image recording.

Masking may be performed in the processing of the inclination image recordings and the darkfield image recordings or the bright field image recordings, wherein error detection is performed with realistic geometric information about the combination of information of the respective inclination image recordings and dark field and bright field image recordings and the detected errors are classified, displayed and / or stored.

Preferably, at least one high-resolution CCD camera with 29 or more megapixels is used for imaging.

The object of the invention is also achieved by a system for determining the defect surface of at least one defect on at least one functional surface of a component or specimen, comprising: a box-shaped housing in which either a fixed storage or a movable linear unit with defined storage and support surface for receiving the component or specimen is provided, at least one light source defined with regard to radiation intensity, direction and position, from which at least one measuring area of the functional surface of the component or test body positioned in the box-shaped housing on the support surface of the linear unit is to be illuminated sequentially from at least four different positions, at least one camera of known position, by means of the one of the functional surface of the component or test specimen in the measuring range in each case a different real image acquisition (raw image) is to create a positioned in the box-shaped housing dark field illumination device, of which is to be generated in the housing dark field illumination, of which Function surface of the component or specimen during the dark field illumination by means of the at least one camera to create a dark field image recording of the at least one functional surface in the at least one measuring range, and

a control and computer system connected to the at least one light source, the dark field illumination device and the at least one camera with automatic control / evaluation software, on the basis of the shape-from-shading method for the four different real image recordings (raw material). Images) to produce the x- or y-tilt image calculations of the at least one functional surface and from the tilt image calculations of the functional surface and the information of the darkfield image acquisition the real defect surface of the at least one defect in the at least one measurement range of the functional surface of the component or Specimen is to be determined.

The dark field illumination device is preferably constructed of LED strips. Preferably, four LED strips are provided, which are positioned in the box-shaped housing in each case parallel to one of the edges of the receiving surface of the fixed bearing or the linear unit on correctly aligned height of the functional surface to be tested and interconnected.

The box-shaped housing can, depending on the structure (fixed storage or displaceable linear unit), be installed in-line in a production or set up close to the production offline.

As light sources, four individual, series-connected reflectors are preferably arranged in the box-shaped housing in its ceiling area, of which the functional surface of the mounted on the storage (fixed storage or linear unit) component or specimen for at least one image acquisition series with four real Shoot images (raw images) one after another with each defined exposure time to illuminate.

Preferably, at least one high-resolution CCD camera with at least 29 megapixels is provided for imaging in the box-shaped housing, from which e.g. three image acquisition series with four real images (raw images) are to be created with different exposure times.

Among other things, the method according to the invention makes it possible to use test systems for the optical control of functional surfaces of components of which not only defects as such can be detected, but also a realistic detection and specification of geometric properties such as length, width and area of the detected defect is guaranteed. In this way, a correct and reproducible transfer of the requirements of quality assurance in the test regulations in the series process is possible. In addition, an adaptation of the test specification is possible at any time, since it can be used directly with length specifications.

The present invention will now be explained with reference to the figures of the drawings.

In these are:

Fig. 1 is a plan view of a schematically illustrated system for determining the defect surface of at least one defect on at least one functional surface of a component or specimen.

Fig. 2 is a schematic view of the box-shaped housing of the system, which is open at the front.

Fig. 3 is a diagrammatic representation of a complete image recording series with four real image recordings (raw images) in each case different illumination direction for the tilt image calculation according to the shape-from-shading method and a fifth image recording in dark field illumination.

Fig. 4 is a diagrammatic representation of three complete image recording series respectively corresponding to Fig. 3, but at different exposure times. 5 is a block diagram-like flow chart of a schematic sequence of the determination of the defect area of at least one defect of a functional surface of a component or test specimen in the production process.

As can be seen from FIGS. 1 and 2, the system according to the invention for determining the defect surface DF of at least one defect surface 7 of at least one functional surface Z (x, y) of a component or test body 1 comprises a box-shaped housing 8 which can be moved, as shown in FIG. 2 shows.

In the lower region of the box-shaped housing 8, either a fixed bearing or a movable linear unit 9 with a defined bearing and rubberized support surface 10 for receiving the component or specimen 1 to be tested is provided. Furthermore, four individual reflectors 3 _a , 3 _b , 3 _c , 3 _{d are} provided in the box-shaped housing 8 in its ceiling region 13 at four positions a, b, c, d as light sources, which defines electrical radiation in terms of radiation intensity, direction and position connected in series and connected to a control and computer system 5, which includes an automatic control / evaluation software.

The functional surface Z (x, y) of the component or specimen 1 positioned on the rubberized support surface 10 of the fixed support or linear unit 9 is, as shown in FIGS. 1 and 2, of the four reflectors 3 _a , 3 _b connected in series. 3 _c , 3 _d sequentially from the four different positions a, b, c, d to illuminate each with a defined exposure time.

As can be seen in FIG. 2, at least one CCD camera 4, preferably with 29 or more megapixels in a defined position, is provided within the box-shaped housing 8 above the bearing surface 10 of the bearing 9 and connected to the control and computer system 5.

During the sequential illumination of the functional surface Z (x, y) of the component or test body 1 positioned on the bearing surface 10 of the bearing 9 by means of the four reflectors 3 _a , 3 _b , 3 _c , 3 _d from the four different positions a, b, c , d in the ceiling portion 13 of the box-shaped housing 8 is at least one of the apparent from Fig. 3 Image - Series S ₁ with four different real images (raw images) R _a , R _b , R _c , R _d of at least one measuring range 2 of Function surface Z (x, y) created. By means of the automatic control / evaluation of the control and computer system 5 takes place then based on the Shape-from-Shading (SfS) method for the four real image recordings (raw images) R _a , R _b , R _c , R _d a tilt image calculation in the x and y direction N _x , N _{y of} the functional surface Z (x, y).

In the box-shaped housing 8 is further connected to the control and computer system 5 dark field illumination device 1 1 is provided, which, as can be seen in Fig. 1, preferably of four LED strips 12 is formed, which are connected together. According to FIG. 1, the four LED strips 12 are each arranged parallel to an edge of the bearing surface 10 of the bearing 9 on which the component or the test body 1 is positioned.

During dark-field illumination by means of the four interconnected LED strips 12, the dark-field image acquisition D of the functional surface Z (x, y) in the at least one measuring region 2 is additionally created by the at least one CCD camera 4, as shown in FIG.

Subsequently, by means of the automatic control / evaluation software unit of the control and computer system 5, the inclination-image calculations N _x and N _{y of} the function surface Z (x, y) and the plane generated on the basis of the shape-from-shading (SfS) method Information of the dark field image recording D of the functional surface Z (x, y) determines the real defect surface DF of the at least one defect 7 in the at least one measuring region 2 of the functional surface Z (x, y) of the component or test body 1.

From Fig. 4 is a schematic diagrammatic representation of three complete image acquisition series S _1; S ₂ , S ₃ respectively corresponding to the image recording series S | 3, but with different exposure times, as is necessary for measuring the defect area DF of a defect 7 of a functional surface Z (x, y) with inhomogeneous reflection properties. Here, the first image acquisition series S | with real first four images (raw images) R _a | R _d4 with an exposure time of 0.01 ms, the second image recording series S ₂ with real four other image recordings R _a6 -Rd9 with an exposure time of 0.025 ms, the third image recording series S ₃ with a further four real image recordings R _a n -Rd i 4 with an exposure time of 0.05 ms, and after the first, the second and the third image acquisition series S ₁ or S ₂ or S ₃ each have a dark field image acquisition D ₅ or Dio or D] ₅ for the respective determination of the defect surface DF of the defect 7 in the at least created a measuring range 2 of the functional surface Z (x, y) of the component or specimen 1.

5 shows a block diagram-like flow diagram of a schematic sequence of the determination of the defect surface DF of at least one defect 7 of the functional surface Z (x, y) of a component or test specimen 1 in the production process with the following method steps:

A) Detecting a component or test piece 1 to be measured by means of e.g. inductive sensor.

B) 1. Start of a new test process consisting of: a) Creation of three complete real image acquisition series S ₁ , S ₂ , S ₃ with four real image recordings (raw images) R _a , R _b , R _c , R _d with different exposure levels as the basis for an SfS calculation in the case of inhomogeneous reflection properties of the functional surface Z (x, y) of the component or specimen 1. b) Otherwise, creating a complete image acquisition series S | each with four real images (raw images) R _a , R _b , R _c , R _d with a defined exposure time as the basis for the SfS calculation.

B) 2. Detecting a part or specimen ID

B) 3. SfS calculation according to point B) 1. a)

B) 4. Slope image calculation N _x , N _y

B) 5. Gray balance over Savitzky-Golay filter

B) 6. Image processing

(Masking / error detection with real geometric information about a combination of inclination image calculations N _x , N _y and information of the dark field image recordings D ₅ , D _{1 0} , D _{1 5} / error classification)

B) 7. Error display

B) 8. Save the results It should be understood that the embodiments of the present invention are not limited to the particular structures, process steps, or materials disclosed herein, but their equivalents may be extended to those of ordinary skill in the relevant arts.

It should be understood that the terminology used herein is used merely to describe particular embodiments and is not to be construed as limiting. The described features, structures or properties may be combined in any suitable manner in one or more embodiments.

LIST OF REFERENCE NUMBERS

1 component, test specimen

2 measuring range

3 light source

3 _a , 3 _b , 3 _C , 3 _d collectors

4 camera, CCD camera with 29 or more megapixels

5 control and computer system

6 System for determining the defect area of a defect

7 defect

8 box-shaped housing

9 fixed storage or movable linear unit

10 rubberized support surface

11 dark field illumination device

12 LED strips

13 ceiling area of the box-shaped housing

Z (x, y) functional surface

a, b, c, d positions of the light source or the collectors

R _a , R _b , R _c , R _d real images (raw images)

R _{a 1} , R _b2 , R _c3 , R _d4 real images (raw images) of the first image acquisition series S ₁ R _a6 , R _b7 , R _c8 , R _d9 real images (raw images) of the second image acquisition series S ₂ R _{a 1 1} , R _{b 1 2} , R _{c 13} , R _{d 14} real image recordings (raw images) of the third image acquisition series S ₃ N _x , N _y inclination image calculations in x or y derivation

S ₁ , S ₂ , S ₃ Bildaufnaiime series SfS method Shape-from-shading method

D Darkfield image capture

D ₅ , D ₁₀ , D ₁₅ Darkfield image acquisition after the first and second b third image acquisition series respectively

H brightfield image capture

DF defect area of a defect

F arrow symbolizing the direction of the manufacturing process

Claims

claims

1. A method for determining the defect area (DF) of at least one defect (7) on at least one functional surface Z (x, y) of a component or test body (1), comprising the method steps:

the component or the test specimen (1) is sequentially formed in at least one measuring range (2) of the functional surface Z (x, y) with at least one light source (3) defined with respect to radiation intensity, direction and position from at least four different positions (a, b, c, d) illuminated,

- Of the functional surface Z (x, y) of the component or specimen (1) with at least one with a control and computer system (5) connected camera (4) known position each have a different real image acquisition (raw image) (R _a , R _b , R _c , R _d ) of the functional surface Z (x, y) in the at least one measuring range (2),

- From the control and computer system (5) are based on the Shape-from-Shading (SfS) method for the four real images (raw images) (R _a , R _b , R _c , R _d ) x or y slope images (N _x , N _y ) of the functional surface Z (x, y) calculated,

a dark field image acquisition (D) of the functional surface Z (x, y) in the measurement area (2) is created by the functional surface Z (x, y) of the component or specimen (1) during dark field illumination, and

the real defect surface (DF) of the at least one defect (7) is determined from the x- or y-inclination-image calculations (N _x , N _y ) of the functional surface Z (x, y) and the information of the dark-field image acquisition (D) ) in the at least one measuring range (2) of the functional surface Z (x, y) of the component or test specimen (1) by means of the control and computer system (5).

2. The method according to claim 1, characterized in that the calculated x- or y-inclination images (N _x , N _y ) are binarized and the at least one defect (7) on the at least one functional surface Z (x, y) on the basis of calculated and binarized inclination images (N _x , N _y ) is detected, wherein at a size of the defect (7) in the range of tenths of millimeters whose geometry in the binarized inclination images (N _x , N _y ) approximately coincides with the real defect area (DF) of the defect (7), but in the case where the size of the defect (7) is in a larger range portions, the (N _x, N _y) are only partially reproduced in the tilt images, on the dark-field image pickup (D) of the functional surface Z (x, y) is binarized with the binarization of the inclination images (N _x, N _y) may be combined and from the combined binarization of the inclination images (N _x , N _y ) and the dark field image acquisition (D), the real geometry of the defect surface (DF) of the defect (7) of the functional surface Z (x, y) is approximately determined.

3. The method according to any one of the preceding claims, characterized in that four individual, in series reflectors (3 _a> 3 _b , 3 _C , 3 _d ) are used as light sources, of which the functional surface Z (x, y) successively with each defined exposure time is illuminated.

4. The method according to any one of the preceding claims, characterized in that as dark field lighting LED lights (12), preferably four LED strips 12 are used, which are connected together.

5. The method according to any one of the preceding claims, characterized in that of the functional surface Z (x, y) by means of a CCD camera (4) three image acquisition series (S |, S ₂ , S ₃ ), each with four real image recordings ( Raw images) (R _a , R _b , R _c , R _d ) are created, wherein the functional surfaces Z (x, y) in each of the three image acquisition series (S _{l 5} S ₂ , S ₃ ) of the series switched reflectors (3a 3 _b , 3 _C , 3 _d ) successively illuminated with a defined exposure time.

6. The method according to any one of the preceding claims, characterized in that at inhomogeneous reflection properties of the functional surface Z (x, y) of the component or specimen (1), the three image acquisition series (S |, S ₂ , S ₃ ), each with four real Imaging (raw images) (R _a , R _b , R _c , R _d ) with different exposure times of the four reflectors (3 _a , 3 _b , 3 _C , 3 _d ) are created by the component or the specimen (1) in at least one measuring range (2) of the functional surface Z (x, y) with the reflectors (3 _a 3 _b , 3 _C , 3 _d ) defined in terms of radiation intensity, direction and position sequentially from the four different positions (a, b, c, d) is illuminated.

7. The method according to any one of the preceding claims, characterized in that the real image recordings (raw images) (R _a , R _b , R _c , R _d ) each of the three image acquisition series (S ₁ , S ₂ , S ₃ ) be created with different exposure times.

8. The method according to claim 7, characterized in that the first image recording series (S ₁ ) with real image recordings (R _{a 1} -R _d4 ) with an exposure time of 0.01 ms, the second image recording series (S ₂ ) with real Image recordings (R _a6 -R _d9 ) with an exposure time of 0.025 ms, the third image acquisition series (S ₃ ) with real image recordings (R _a n -R _{d 14} ) with an exposure time of 0.05 ms, and after the first, the second and the third image recording series (S ₁ or S ₂ or S ₃ ) each have a dark field image recording (D ₅ or D ₁₀ or D ₁₅ ) for the respective determination of the defect surface (DF) of the at least one defect (7 ) is created.

9. The method according to any one of the preceding claims, characterized in that instead of the dark field illumination, a bright field illumination is generated while a bright field image acquisition (H) of the at least one functional surface Z (x, y) in the at least one measuring range (2) is created , and from the inclination image calculations (N _x , N _y ) of the functional surface Z (x, y) and the information of the bright field image acquisition (H) the real defect surface (DF) of the at least one defect (7) in the at least one measurement region (2) the functional surface Z (x, y) of the component or specimen (1) by means of the control and computer system (5) is determined.

10. The method according to any one of the preceding claims, characterized in that in the creation of the respective different inclination images (N _x , N _y ) of the at least one functional surface Z (x, y) in the at least one measuring range (2) a grayscale over Savitzky Golay filter is done.

11. The method according to any one of the preceding claims, characterized in that the at least one measuring range (2) of the functional surface Z (x, y) is divided into sectors, and a separate parameterization per tilt image acquisition (N _x , N _y ) and each Dark field image acquisition (D) or per bright field image acquisition (H).

12. The method according to any one of the preceding claims, characterized in that in the processing of tilt image recordings (N _x , N _y ) after the Shape-from-Shading (SfS) method and the dark field image recordings (D) and the Hidden field image recordings (H) a masking, wherein an error detection with realistic geometric information on the combination of information of the respective inclination image recordings (N _x , N _y ) and darkfield image recordings (D) and the bright field image recordings (H) performed and the detected errors are classified, displayed and / or stored.

13. The method according to any one of the preceding claims, characterized in that for image recording at least one high-resolution CCD camera (4) is used with at least 29 megapixels.

14. System for determining the defect surface (DF) of at least one defect (7) in at least one measuring region (2) of at least one functional surface Z (x, y) of a component or test body (1), comprising: a box-shaped housing (8), in a fixed bearing or a movable linear unit (9) with a defined bearing and support surface (10) for receiving the component or specimen (1) is provided, at least one with respect to radiation intensity, direction and position defined light source (3), of which Measuring range (2) of the functional surface Z (x, y) of the component or test body (1) positioned in the box-shaped housing (8) on the bearing surface (10) of the bearing (9) sequentially from at least four different positions (a, b, c , d) to illuminate, at least one camera (4) known position, by means of the function of the surface Z (x, y) of the component or specimen (1) each have a different real Bildaufna hme (raw images) (R _a , Rt>, Rc, Rd) is to be created in the at least one measuring range (2), a in the box-shaped housing (8) positioned dark field illumination device (1 1), of which in Housing (8) is to produce a dark field illumination, wherein of the at least one functional surface Z (x, y) of the component or specimen (1) during the dark field illumination by means of the at least one camera (4) a dark field image recording (D) of the functional surface Z (x, y) in the at least one measuring range (2) is to create, and a control and computer system (5) connected to the at least one light source (3), the dark field illumination device (11) and the at least one camera (4) with automatic control / evaluation software, on the basis of which from shading (SfS) method for each real image record (raw images) (R _a , R _b , R _c , R _d ) an x or y slope image calculation (N _x , N _y ) of the functional surface Z (x, y) and from the various inclination image calculations (N _x , N _y ) of the functional surface Z (x, y) and the information of the dark field image acquisition (D) the real defect surface (DF) of the at least one defect ( 7) in which at least one measuring range (2) of the functional surface Z (x, y) of the component or test specimen (1) is to be determined.

15. Plant according to claim 14, characterized in that the dark field illumination device (1 1) of LED strips (12), preferably of four parallel LED strips (12) is formed.

16. Plant according to claim 14 and 15, characterized in that each one of the four parallel LED strips (12) in the box-shaped housing (8) in each case parallel to one of the edges of the component or the test body (1) receiving defined bearing surface (10 ) is arranged.

17. Installation according to one of claims 14 to 16, characterized in that in the box-shaped housing (8) in the ceiling region (13) at four positions (a, b, c, d) as light sources four individual, series-connected reflectors (3 _a> 3 _b , 3 _C , 3 _d ), of which the functional surface Z (x, y) of the component or test body (1) positioned on the bearing surface (10) of the bearing (9) for at least one image recording series (FIG. S ₁ ) with four real image recordings (raw images) (R _a , R _b , R _c , R _d ) is to be illuminated sequentially with each defined exposure time.

18. Installation according to one of claims 14 to 17, characterized in that at least one high-resolution CCD camera (4) is provided with at least29 megapixels, of the three image acquisition series (S ₁ , S ₂ , S ₃ ), each with four real Imaging (raw images) (R _a , R _b , R _c , Rd) are to create.

19. Plant according to one of claims 14 to 18, characterized in that the real image recordings (raw images) (R _a , R _b , R _c , R _d ) of each of the three image acquisition series (S ₁ , S ₂ , S ₃ ) are to be created with different exposure times.

20. Plant according to claim 19, characterized in that the first image recording series (S ₁ ) with image recordings (raw images) (R _{a 1} , R _d4 ) with an exposure time of 0.01 ms, the second image recording series (S ₂ ) with images (raw images) (R _a6 -Rd9) with an exposure time of 0.025 ms, the third image acquisition series (S ₃ ) with images (raw images) (R _{a 1 1} -Rd i4) with an exposure time of 0 , 05 ms and after the first, second and third image acquisition series (S ₁ or S ₂ or S ₃ ) each have a dark field image acquisition (D ₅ or D ₁₀ or D 15) for the respective determination of real defect surface (DF) of at least one defect (7) is to create.

21. Installation according to one of claims 14 to 20, characterized in that instead of the dark field illumination device (1 1) a bright field illumination device is provided, wherein a bright field image recording (H) of the at least one functional surface Z (x, y) in to create the at least one measuring range (2) and from the inclination image calculations (N _x , N _y ) of the functional surface Z (x, y) and the information of the bright field image recording (H) the real defect surface (DF) of the at least one defect (7) in which at least one measuring range (2) of the functional surface Z (x, y) of the component or test specimen (1) is to be determined by means of the control and computer system (5).