DE102004054508A1 - Camera-based object examination method, for detecting contraction e.g. in pressed part, involves arranging object and light sources, so that distribution of vector projection on object surface and defect circumference forms right angle - Google Patents
Camera-based object examination method, for detecting contraction e.g. in pressed part, involves arranging object and light sources, so that distribution of vector projection on object surface and defect circumference forms right angle Download PDFInfo
- Publication number
- DE102004054508A1 DE102004054508A1 DE102004054508A DE102004054508A DE102004054508A1 DE 102004054508 A1 DE102004054508 A1 DE 102004054508A1 DE 102004054508 A DE102004054508 A DE 102004054508A DE 102004054508 A DE102004054508 A DE 102004054508A DE 102004054508 A1 DE102004054508 A1 DE 102004054508A1
- Authority
- DE
- Germany
- Prior art keywords
- camera
- light source
- vector
- illumination
- image
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/0002—Inspection of images, e.g. flaw detection
- G06T7/0004—Industrial image inspection
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/50—Depth or shape recovery
- G06T7/55—Depth or shape recovery from multiple images
- G06T7/586—Depth or shape recovery from multiple images from multiple light sources, e.g. photometric stereo
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
- G06V10/00—Arrangements for image or video recognition or understanding
- G06V10/10—Image acquisition
- G06V10/12—Details of acquisition arrangements; Constructional details thereof
- G06V10/14—Optical characteristics of the device performing the acquisition or on the illumination arrangements
- G06V10/145—Illumination specially adapted for pattern recognition, e.g. using gratings
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T2207/00—Indexing scheme for image analysis or image enhancement
- G06T2207/30—Subject of image; Context of image processing
- G06T2207/30108—Industrial image inspection
- G06T2207/30136—Metal
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T2207/00—Indexing scheme for image analysis or image enhancement
- G06T2207/30—Subject of image; Context of image processing
- G06T2207/30108—Industrial image inspection
- G06T2207/30164—Workpiece; Machine component
Abstract
Description
Die Erfindung betrifft ein Verfahren und eine Vorrichtung zur kamera-basierten Erkennung von Einschnürungen bei Pressteilen nach den Oberbegriffen der Patentansprüche 1 und 4.The The invention relates to a method and a device for camera-based Detection of constrictions in pressed parts according to the preambles of claims 1 and 4th
Insbesondere bei der Produktion von Pressteilen aus Stahlblechen oder Aluminium blechen kommt es häufig zu Einschnürungen und somit Fehlstellen auf dem Pressteil. Um derartige Fehler zu erkennen, werden die Pressteile in der Regel in einem kostspieligen Vorgang einer Sichtprüfung durch Produktionspersonal unterzogen. Zunehmend kommen jedoch im produzierenden Gewerbe zur Einsparung von Personalkosten und zur Beschleunigung des Prüfverfahrens automatisierte kamerabasierte Prüfsysteme zum Einsatz. Ein häufig zu Oberflächenprüfzwecken angewandtes optisches Verfahren ist hierbei die Stereometrie, bei dem die zu untersuchende Oberfläche aus leicht unterschiedlichem Blickwinkel aufgenommen wird und aus der Auswertung der geringen stereoskopischen Abweichungen die Struktur der Oberfläche errechnet wird. Ein weiters kamera-basiertes Objektprüfverfahren, bei welchem zur Rekonstruktion des Profils von Strukturen auf Oberflächen eine Schattenanalyse mit einer Bildverarbeitung nach der Methode des Shape-from-Shading kombiniert wird durch Wöhler beschrieben (K. Hafezi, C. Wöhler, A general framework for three-dimensional surface reconstruction by self-consistent fusion of shading and shadow features and its application to industrial quality inspection tasks, SPIE Photonics Europe, Strasbourg, 2004). Hierbei werden mindestens zwei Bilder desselben Bereichs der Oberfläche des zu prüfenden Objekts ausgewertet, wobei die Bilder beispielsweise aus nahezu vertikaler Perspektive aufgenommen werden und die Beleuchtung aus verschiedenen Richtungen unter flachem Winkel zur Oberfläche erfolgt. Erhebungen oder Vertiefungen auf der Oberfläche zeigen so auf den Aufnahmen einen deutlichen Schattenwurf, dessen Lage mit der Lichteinstrahlung variiert. Geneigte Flächen sind durch hellere Reflektionen identifizierbar. Durch Analyse von Schattenkonturen und Umrisslinien heller Bereiche lässt sich das Höhenprofil einer Struktur auf der Oberfläche bestimmen und so beispielsweise der verlauf eines Grates rekonstruieren. Durch die Integration der Methode des Shape-from-Shading können auch flache Neigungsänderungen durch Auswertung von Helligkeitsverläufen bestimmt werden und somit eine gut mit dem Original übereinstimmende 3D-Rekonstruktion der Oberfläche erreicht werden. Nachteilig wirkt sich bei dem Verfahren jedoch der hohe Rechenaufwand aus.Especially in the production of pressed parts made of sheet steel or aluminum Sheet metal often happens to constrictions and thus defects on the pressed part. To such mistakes too recognize, the pressed parts are usually in a costly Process of a visual inspection subjected by production staff. Increasingly, however, come in the manufacturing industry to save on personnel costs and the Acceleration of the test procedure automated camera-based inspection systems for use. A common too Oberflächenprüfzwecken applied optical method here is the stereometry, in the surface to be examined is taken from slightly different angles and off the evaluation of the small stereoscopic deviations the structure the surface is calculated. A further camera-based object inspection method, in which for reconstructing the profile of structures on surfaces one Shadow analysis with image processing using the method of Shape from shading is combined by Wöhler (K. Hafezi, C. Wöhler, A general framework for three-dimensional surface reconstruction by self-consistent fusion of shading and shadow features and its application to industrial quality inspection tasks, SPIE Photonics Europe, Strasbourg, 2004). Here are at least two pictures same area of the surface of the test to be tested Object evaluated, the images, for example, from almost vertical perspective and the lighting off different directions at a slight angle to the surface. Elevations or depressions on the surface thus show up on the recordings a clear shadow, its location with the light irradiation varied. Inclined surfaces are identifiable by brighter reflections. By analysis of shadow contours and outlines of bright areas can be the elevation profile a structure on the surface determine and thus for example reconstruct the course of a ridge. By integrating the method of shape-from-shading can also be flat inclination changes be determined by evaluating brightness gradients and thus a good match with the original 3D reconstruction of the surface be achieved. However, the process is disadvantageous the high computational effort.
Aufgabe der Erfindung ist es deshalb ein Verfahren und eine zur Durchführung des Verfahrens geeignete Vorrichtung zu finden, mittels welchen mit geringer Rechenleistung, insbesondere Einschnürungen in Pressteilen erkannt werden können.task The invention is therefore a method and a for carrying out the Method to find suitable device by means of which low computing power, especially constrictions detected in pressed parts can be.
Die Aufgabe wird durch eine Verfahren und ein für die Durchführung des Verfahrens geeignete Vorrichtung nach den Oberbegriffen der Patentansprüche 1 und 4 gelöst. Vorteilhafte Ausgestaltungen und Weiterbildungen der Erfindung werden in den Unteransprüchen beschrieben.The Task is performed by a procedure and for the implementation of the Method suitable device according to the preambles of claims 1 and 4 solved. Advantageous embodiments and further developments of the invention will be in the subclaims described.
Das
erfindungsgemäße Verfahren
zur kamera-basierten Prüfung
von Objekten eignet sich insbesondere zur Erkennung von Einschnürungen bei
Pressteilen. Dies sind bedingt durch den Pressvorgang, in der Regel
längs auf
dem durch Pressung geschaffenen Objekt verlaufende Fehlstellen.
Nachfolgend wird unter Zuhilfenahme der Figur die Erfindung im Detail
beschrieben. Wie aus der Figur ersichtlich wird im Rahmen der Objektprüfung das
Objekt (
Bei der Quotientenanalyse werden die korrelierenden Bildpunkte zweier Bildaufnahmen miteinander in Beziehung gesetzt, um zumindest mit Teilen dieser Bilddaten die Oberflächensteigungen p(u,v) an den Positionen (u,v) der Objektoberfläche rekonstruiert werden. Dabei ist es zum einen denkbar, von einem der zu prüfenden Oberflächengebiete jeweils nur 2 Bildaufnahen zu erzeugen, oder auf der Basis mehrer unterschiedlicher Beleuchtungsvektoren mehrere Bildaufnahmen eines Teilgebiets zu erzeugen und beispielsweise in einem Iterativen Prozess die beiden hierzu am besten geeigneten Bildaufnahmen miteinander zu korrelieren.at The quotient analysis becomes the correlating pixels of two Image captures related to each other, at least with Divide these image data, the surface slopes p (u, v) to the Positions (u, v) of the object surface are reconstructed. there It is conceivable, for one, of one of the surface areas to be tested to produce only 2 image acquisitions, or on the basis of several different illumination vectors take several pictures of a Subregion and, for example, in an iterative process the two best suited for this purpose to correlate.
In
besonders vorteilhafter Weise basiert die Quotientenanalyse auf
einem Gleichungssystem, bei welchem für die Ober flächensteigung
p(u,v) in senkrecht zum Verlauf der länglich verlaufenden Fehlstelle
(
Hierbei
werden die entsprechenden Beleuchtungsvektoren (
Insbesondere
zur Vermeidung von spekularen Reflexionen ist es besonders gewinnbringend,
wenn die Kamera (
Um
die für
das erfindungsgemäße Verfahren
notwendigen geometrischen Bedingungen erfüllen zu können (insbesondere um die Lichtquellen
(
In
besonderer Weise verfügt
die erfindungsgemäße Vorrichtung
auch über
ein Positioniermittel für
die Kamera (
Besonders
vorteilhaft kann die Vorrichtung dadurch ausgestaltet werden, dass
die wenigstens eine Lichtquelle (
Claims (9)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102004054508A DE102004054508A1 (en) | 2004-08-09 | 2004-11-11 | Camera-based object examination method, for detecting contraction e.g. in pressed part, involves arranging object and light sources, so that distribution of vector projection on object surface and defect circumference forms right angle |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102004038760.5 | 2004-08-09 | ||
DE102004038760 | 2004-08-09 | ||
DE102004054508A DE102004054508A1 (en) | 2004-08-09 | 2004-11-11 | Camera-based object examination method, for detecting contraction e.g. in pressed part, involves arranging object and light sources, so that distribution of vector projection on object surface and defect circumference forms right angle |
Publications (1)
Publication Number | Publication Date |
---|---|
DE102004054508A1 true DE102004054508A1 (en) | 2006-02-23 |
Family
ID=35721584
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DE102004054508A Withdrawn DE102004054508A1 (en) | 2004-08-09 | 2004-11-11 | Camera-based object examination method, for detecting contraction e.g. in pressed part, involves arranging object and light sources, so that distribution of vector projection on object surface and defect circumference forms right angle |
Country Status (1)
Country | Link |
---|---|
DE (1) | DE102004054508A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN107957234A (en) * | 2016-10-17 | 2018-04-24 | 中国航空工业集团公司北京航空制造工程研究所 | A kind of method and device for measuring normal vector of arbitrary point of free-form surface |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19511534C2 (en) * | 1995-03-29 | 1998-01-22 | Fraunhofer Ges Forschung | Method and device for detecting 3D defects in the automatic inspection of surfaces with the aid of color-capable image evaluation systems |
US6321137B1 (en) * | 1997-09-04 | 2001-11-20 | Dynalog, Inc. | Method for calibration of a robot inspection system |
-
2004
- 2004-11-11 DE DE102004054508A patent/DE102004054508A1/en not_active Withdrawn
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19511534C2 (en) * | 1995-03-29 | 1998-01-22 | Fraunhofer Ges Forschung | Method and device for detecting 3D defects in the automatic inspection of surfaces with the aid of color-capable image evaluation systems |
US6321137B1 (en) * | 1997-09-04 | 2001-11-20 | Dynalog, Inc. | Method for calibration of a robot inspection system |
Non-Patent Citations (9)
Title |
---|
akazawa, K. et al.: Developement of Damage Detec-tion System for Container" In: Proc. IEEE IECON 21st International Conference on Industrial Elec- tronics, Control, and Instrumentation, S. 1160-1163, 1995 * |
Conference on Computer Vision and Pattern Recogni- tation, S.492-496 |
Conference on Computer Vision and Pattern Recogni-tation, S.492-496 * |
Kim, B. und Burger, P.: Calculation of Surface Position and Orientation Using the Photometric Stereo Method", In: Proc. CVPR'88: The Computer Society * |
Marc Levoy: The Standford Spherical Gantry. http:/ /graphics.stanford.edu/projects/gantry/27.April200 4 |
Marc Levoy: The Standford Spherical Gantry. http://graphics.stanford.edu/projects/gantry/27.April2004 * |
Nakazawa, K. et al.: Developement of Damage Detec- tion System for Container" In: Proc. IEEE IECON 21st International Conference on Industrial Elec- tronics, Control, and Instrumentation, S. 1160-116 3, 1995 |
Photometric Stereo Method" In: Proc. CVPR'88: The Computer Society * |
Zhang, R. et al.: Shape from Shading: A Survey. In: IEEE Transactions on Pattern Analysis and Ma- chine Intelligence, Vol.21, No.8, S.690-706, 1999 * |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN107957234A (en) * | 2016-10-17 | 2018-04-24 | 中国航空工业集团公司北京航空制造工程研究所 | A kind of method and device for measuring normal vector of arbitrary point of free-form surface |
CN107957234B (en) * | 2016-10-17 | 2023-09-29 | 中国航空制造技术研究院 | Method and device for measuring normal vector at any point of free-form surface |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP1716410B1 (en) | Method and system for inspecting surfaces | |
DE102010015566B4 (en) | Method and system for measuring reflective surfaces | |
EP1987348B1 (en) | Method of detecting defects on the surface of a cylindrical object | |
DE102009058215B4 (en) | Method and device for surface inspection of a bearing component | |
EP2167947A1 (en) | Method and device for the optical inspection of a surface of an object | |
DE102015113051B4 (en) | Measuring device, printed circuit board testing device and method for the control thereof | |
DE102015109843B4 (en) | Printed circuit board testing device and method for its control | |
DE102016107900B4 (en) | Method and device for determining the edge of a measurement object in optical measurement technology | |
WO2015169730A1 (en) | Method and sensor for determining the surface of an object by means of deflectometry | |
WO2004051186A1 (en) | Method and device for optical form measurement and/or estimation | |
DE10317078B4 (en) | Method and device for analyzing reflective surfaces | |
DE102006006876A1 (en) | Method of detecting the contour of a reflective surface using a virtual image of the reflective points | |
DE102004033526A1 (en) | Analysis of at least partly reflecting surfaces involves varying relative orientation/position of object, pattern generation device and/or image receiver(s) for image reflected at surface, to obtain surface, especially geometry, information | |
DE102018214280A1 (en) | Inspection system and method for correcting an image for inspection | |
DE60317595T2 (en) | Three-dimensional edge localization using lateral illumination | |
WO2009083248A1 (en) | Method and apparatus for optically inspecting a surface of an object | |
DE102017106764A1 (en) | TEST DEVICE, STORAGE MEDIUM AND PROGRAM | |
DE102004054508A1 (en) | Camera-based object examination method, for detecting contraction e.g. in pressed part, involves arranging object and light sources, so that distribution of vector projection on object surface and defect circumference forms right angle | |
DE102015203396A1 (en) | Method and device for determining the topography of a surface | |
WO2002033348A1 (en) | Optically measuring an object using a coordinate measuring device, cameras and lighting sources | |
WO2018068775A1 (en) | 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 | |
DE102018008154B4 (en) | Method and device for optically detecting the shape of an object | |
DE102008036710A1 (en) | Method for three-dimensional optical measuring of object with topometric measuring process, involves selecting partial areas of objects such that reflections of patterns on surface of object do not influence patterns in partial areas | |
DE102010029627B4 (en) | Apparatus and method for determining the structure of a specular surface of an object | |
EP2322915B1 (en) | Apparatus and method for creating a variable spatial and/or temporal thermal radiation pattern for deflectometry, and deflectometric apparatus. |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
OP8 | Request for examination as to paragraph 44 patent law | ||
8127 | New person/name/address of the applicant |
Owner name: DAIMLERCHRYSLER AG, 70327 STUTTGART, DE |
|
8127 | New person/name/address of the applicant |
Owner name: DAIMLER AG, 70327 STUTTGART, DE |
|
8139 | Disposal/non-payment of the annual fee |