WO1996022507A1 - Bildverarbeitungsverfahren zur ermittlung der strukturfestigkeit eines prüfobjektes mit diffus streuender oberfläche - Google Patents
Bildverarbeitungsverfahren zur ermittlung der strukturfestigkeit eines prüfobjektes mit diffus streuender oberfläche Download PDFInfo
- Publication number
- WO1996022507A1 WO1996022507A1 PCT/EP1996/000187 EP9600187W WO9622507A1 WO 1996022507 A1 WO1996022507 A1 WO 1996022507A1 EP 9600187 W EP9600187 W EP 9600187W WO 9622507 A1 WO9622507 A1 WO 9622507A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- image
- test object
- gray value
- value image
- shearing
- Prior art date
Links
- 238000012360 testing method Methods 0.000 title claims abstract description 30
- 238000003672 processing method Methods 0.000 title abstract description 3
- 230000005855 radiation Effects 0.000 claims abstract description 18
- 238000000034 method Methods 0.000 claims description 22
- 238000010008 shearing Methods 0.000 claims description 20
- 230000004069 differentiation Effects 0.000 claims description 10
- 230000001427 coherent effect Effects 0.000 claims description 4
- 238000012545 processing Methods 0.000 claims description 4
- 239000003086 colorant Substances 0.000 claims description 3
- 238000003384 imaging method Methods 0.000 claims description 2
- 238000006243 chemical reaction Methods 0.000 abstract description 2
- 230000006641 stabilisation Effects 0.000 abstract 1
- 230000000694 effects Effects 0.000 description 17
- 238000009826 distribution Methods 0.000 description 10
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000013461 design Methods 0.000 description 3
- 238000010276 construction Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/16—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge
- G01B11/161—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge by interferometric means
- G01B11/162—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge by interferometric means by speckle- or shearing interferometry
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M17/00—Testing of vehicles
- G01M17/007—Wheeled or endless-tracked vehicles
- G01M17/02—Tyres
- G01M17/027—Tyres using light, e.g. infrared, ultraviolet or holographic techniques
Definitions
- Image processing method to determine the structure of a test object with a diffusely scattering surface
- the invention relates to a method for determining the structural strength of a test object with a diffusely scattering surface according to the preamble of claim 1.
- a generic method is known from DE-OS 42 31 578 AI.
- a test object is irradiated with coherent light and the radiation scattered back from the test object is divided into two partial radiations.
- the two partial radiations are brought together again in such a way that the two partial radiations are slightly tilted (shearing effect).
- the partial radiations carrying the image information are fed to an electronic image sensor system.
- the test object is imaged on the image sensor by the imaging component.
- the radiation incident on the image sensor is converted into digital signals after an A / D conversion.
- the surface of the test object initially has the state 1, after an applied deformation it has the state 2.
- the recording of the surface state 1 takes place in such a way that in a first image sequence a partial radiation with respect to the second partial radiation is gradually shifted in phase.
- the image sequence is typically stored in the temporary memory of a computer.
- a second image sequence is generated from the surface state 2 in the same way.
- the individual steps of The first and the second image sequence are processed further in a computer to form a modulo 2 ⁇ x image.
- the aim of the deformation to be applied is always to identify weak points by the fact that such points have a significantly different deformation than the environment.
- the image resulting from this procedure is on the one hand the result of the constructive and geometric design of the test object and on the other hand a sequence of structural inhomogeneities.
- the disadvantage of this method is that the effect of structural inhomogeneities can only be recognized if this effect is significantly greater than the constructively or geometrically caused effects.
- the invention is based on the object of further developing the method known from DE-OS 42 31 578 A1 in such a way that structural inhomogeneities can be distinguished from structural and geometric effects in a simple manner.
- the partial differentiation of a modulo 2 ⁇ image which is carried out numerically and converted into a resulting gray value image, makes it possible to distinguish structural inhomogeneities from structural or geometric effects, since structural inhomogeneities generally have larger gradients than constructive ones or geometric effects.
- An advantageous method consists in illuminating the test object with coherent light from a plurality of laser diodes, each of which generates a light spot on the test object.
- the method is advantageously carried out in such a way that the shearing and differentiation direction coincides with the direction of the short semiaxis of the elliptically pronounced structural inhomogeneity.
- the direction that includes an angle of 45 ° with both short ellipse half axes is advantageously chosen as the shearing and differentiation direction.
- the method according to the invention has the advantage that structural inhomogeneities clearly stand out from structural or geometrical effects in the resulting image and are therefore easy to identify.
- a further advantage of the method according to the invention is the direct possible assignment of the respective structural inhomogeneities to the concave or convex type.
- Fig. 1 the gray value distribution based on the test geometry in
- Fig. 2 the actual gray value distribution when exposed to variable stiffness of the tire cross-section
- Fig. 7 typical structural weaknesses on a tire.
- the modulo 2 ⁇ image obtained from DE-OS 42 31 578 AI is first converted into a gray value image such that the gray values of the individual image points indicate the difference in the deformation of two adjacent points on the test object.
- Development methods suitable for this. are e.g. described in "Digital Processing and Evaluation of Interference Images", Wolfgang Osten, Akademie-Verlag Berlin, 1991, pages 138 to 144 and in “Proceedings of the I. International Workshop on Automatic Processing of Fringe Patterns", Akademie-Verlag Berlin, 1989, Pages 23 to 31.
- the gray value distribution is determined by the deformation difference in the shearing direction, the shearing direction being defined as the tilting direction of the one partial radiation against the other partial radiation.
- Typical gray value distributions are shown in FIGS. 1 and 2.
- FIG. 1 shows the theoretical gray value distribution on the side wall of a homogeneous tire when the pressure is reduced.
- FIG. 2 shows the gray value distribution actually measured. This course is essentially determined by the design of the tire cross-section. It can be seen from FIG. 2 that the effect of structural inhomogeneities can only be recognized if this effect is significantly greater than the constructionally or geometrically caused effects.
- the gray value image ie the deformation difference
- the gray value image is on the one hand the result of the constructive and geometric design of the test object and on the other hand a sequence of structural inhomogeneities.
- Structural inhomogeneities can thus be displayed in a simple manner by specifying gray value thresholds. It is advantageous to mark gray value areas by means of colors (for example green-yellow-red). This considerably simplifies the good / bad decision. In many cases it is necessary to know the sign of the inhomogeneity (eg concave or convex bulge). In the case of a tire, for example, an “impact” increases the local structural strength, but structural weaknesses are sought. The distinction can only be made by recognizing the sign of the change in deformation when the pressure changes inside the tire.
- FIG. 7 In the case of a tire, typical structural weaknesses are shown in FIG. 7.
- the position "1" shows a belt edge detachment, respectively. Pre-release steps. It typically shows a tangential course, the best indication is through radial shearing / differentiation. Structural weaknesses across the tire cross-section manifest themselves in radially oriented folds (position "2"), * the best indication is given by tangential shearing / differentiation.
- the 45 "direction is an acceptable compromise for both types of error.
Abstract
Description
Claims
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA002185572A CA2185572C (en) | 1995-01-16 | 1996-01-15 | Image processing method for determining the structural strength of a test object with a diffuse-scattering surface |
US08/704,663 US5760888A (en) | 1995-01-16 | 1996-01-15 | Object to having a image processing for determining the structural of a test object with a diffuse-scattering surface |
DE59602371T DE59602371D1 (de) | 1995-01-16 | 1996-01-15 | Bildverarbeitungsverfahren zur ermittlung der strukturfestigkeit eines prüfobjektes mit diffus streuender oberfläche |
EP96901293A EP0750735B1 (de) | 1995-01-16 | 1996-01-15 | Bildverarbeitungsverfahren zur ermittlung der strukturfestigkeit eines prüfobjektes mit diffus streuender oberfläche |
AU45372/96A AU4537296A (en) | 1995-01-16 | 1996-01-15 | Image processing method for determining the structural strength of a test object with a diffuse-scattering surface |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19501073.6 | 1995-01-16 | ||
DE19501073A DE19501073A1 (de) | 1995-01-16 | 1995-01-16 | Bildverarbeitungsverfahren zur Ermittlung der Strukturfestigkeit eines Prüfobjektes mit diffus streuender Oberfläche |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1996022507A1 true WO1996022507A1 (de) | 1996-07-25 |
Family
ID=7751568
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP1996/000187 WO1996022507A1 (de) | 1995-01-16 | 1996-01-15 | Bildverarbeitungsverfahren zur ermittlung der strukturfestigkeit eines prüfobjektes mit diffus streuender oberfläche |
Country Status (7)
Country | Link |
---|---|
US (1) | US5760888A (de) |
EP (1) | EP0750735B1 (de) |
AT (1) | ATE182004T1 (de) |
AU (1) | AU4537296A (de) |
CA (1) | CA2185572C (de) |
DE (2) | DE19501073A1 (de) |
WO (1) | WO1996022507A1 (de) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
AU724324B2 (en) * | 1995-07-17 | 2000-09-14 | Board Of Regents, The University Of Texas System | p16 expression constructs and their application in cancer therapy |
Families Citing this family (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
ES2188696T3 (es) * | 1996-08-06 | 2003-07-01 | Nova C O R D Ag | Procedimiento para detectar los defectos de los neumaticos. |
EP0884560B1 (de) * | 1997-06-10 | 2005-10-26 | Beissbarth GmbH | Verfahren und Vorrichtung zum Prüfen von Reifen |
DE19731486C2 (de) * | 1997-07-22 | 2001-02-22 | Beissbarth Gmbh | Reifenprüfvorrichtung |
EP0955533A3 (de) * | 1998-05-07 | 2000-02-02 | Nova C.O.R.D. Ag | Verfahren zur Strukturfestigkeitsprüfung von Reifen, vorzugsweise von LKW-Reifen |
DE19859725C2 (de) * | 1998-12-23 | 2001-02-22 | Stefan Dengler | Vorrichtung zur Ermittlung von Verformungen an einer Objektoberfläche, insbesondere einer diffus streuenden Objektoberfläche und Verwendung der Vorichtung |
DE19859801C2 (de) * | 1998-12-23 | 2001-08-30 | Bernward Maehner | Verfahren zur echtzeitfähigen Ermittlung und Darstellung von Verformungen oder Verschiebungen von Prüfobjekten und Vorrichtung zur Durchführung des Verfahrens |
DE19906681C2 (de) * | 1999-02-18 | 2002-01-24 | Bernward Maehner | Verfahren zur Ermittlung von Strukturmerkmalen, insbesondere Strukturdefekten, an Prüfobjekten mit diffus streuender Oberfläche |
DE19922775A1 (de) * | 1999-05-18 | 2000-11-23 | Beissbarth Gmbh | Reifenprüfverfahren |
US7436504B2 (en) * | 2003-09-10 | 2008-10-14 | Shear Graphics, Llc | Non-destructive testing and imaging |
US6934018B2 (en) * | 2003-09-10 | 2005-08-23 | Shearographics, Llc | Tire inspection apparatus and method |
US7187437B2 (en) * | 2003-09-10 | 2007-03-06 | Shearographics, Llc | Plurality of light sources for inspection apparatus and method |
US9988242B1 (en) | 2017-01-11 | 2018-06-05 | Otis Elevator Company | Elevator rail healthy monitoring method |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5020904A (en) * | 1989-09-06 | 1991-06-04 | Mcmahan Jr Robert K | Dynamic laser speckle profilometer and method |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5065331A (en) * | 1981-05-18 | 1991-11-12 | Vachon Reginald I | Apparatus and method for determining the stress and strain in pipes, pressure vessels, structural members and other deformable bodies |
US4591996A (en) * | 1981-05-18 | 1986-05-27 | Vachon Reginald I | Apparatus and method for determining stress and strain in pipes, pressure vessels, structural members and other deformable bodies |
US5011280A (en) * | 1987-12-07 | 1991-04-30 | Hung Yau Y | Method of measuring displacement between points on a test object |
US5091776A (en) * | 1990-11-08 | 1992-02-25 | Laser Technology, Inc. | Apparatus and method for enhancing the quality of a video signal produced by electronic shearography |
US5146289A (en) * | 1990-12-21 | 1992-09-08 | Laser Technology, Inc. | Nondestructive testing using air-coupled acoustic excitation |
DE4231578C2 (de) * | 1992-09-21 | 1995-06-29 | Nova C O R D Ag | Verfahren zur Ermittlung von Verformungen an einem Prüfobjekt mit diffus streuender Oberfläche, insbesondere an Reifen, sowie Vorrichtung zur Durchführung des Verfahrens |
US5481356A (en) * | 1994-04-25 | 1996-01-02 | Northwestern University | Apparatus and method for nondestructive testing using additive-subtractive phase-modulated interferometry |
-
1995
- 1995-01-16 DE DE19501073A patent/DE19501073A1/de not_active Withdrawn
-
1996
- 1996-01-15 AU AU45372/96A patent/AU4537296A/en not_active Abandoned
- 1996-01-15 AT AT96901293T patent/ATE182004T1/de not_active IP Right Cessation
- 1996-01-15 US US08/704,663 patent/US5760888A/en not_active Expired - Fee Related
- 1996-01-15 EP EP96901293A patent/EP0750735B1/de not_active Expired - Lifetime
- 1996-01-15 CA CA002185572A patent/CA2185572C/en not_active Expired - Fee Related
- 1996-01-15 DE DE59602371T patent/DE59602371D1/de not_active Expired - Fee Related
- 1996-01-15 WO PCT/EP1996/000187 patent/WO1996022507A1/de active IP Right Grant
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5020904A (en) * | 1989-09-06 | 1991-06-04 | Mcmahan Jr Robert K | Dynamic laser speckle profilometer and method |
Non-Patent Citations (3)
Title |
---|
K.A. STETSON: "Phase-step Interferometry of Irregular Shapes by using an Edge-following Algorithm", APPLIED OPTICS, vol. 31, no. 25, 1 September 1992 (1992-09-01), NEW YORK, NY, US, pages 5320 - 5325, XP002002767 * |
R. SPOOREN, A.A. DYRSETH, M. VAZ: "Electronic Shear Interferometry: application of a (double-)pulsed Laser", APPLIED OPTICS, vol. 32, no. 25, 1 September 1993 (1993-09-01), WASHINGTON, DC, US, pages 4719 - 4727, XP002002766 * |
ULF SCHNARS: "Direct Phase determination in Hologram Interferometry with use of digitally recorded Holograms", J.OF THE OPTICAL SOCIETY OF AMERICA A, vol. 11, no. 7, July 1994 (1994-07-01), WASHINGTON, DC, US, pages 2011 - 2015, XP002002768 * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
AU724324B2 (en) * | 1995-07-17 | 2000-09-14 | Board Of Regents, The University Of Texas System | p16 expression constructs and their application in cancer therapy |
Also Published As
Publication number | Publication date |
---|---|
AU4537296A (en) | 1996-08-07 |
ATE182004T1 (de) | 1999-07-15 |
DE19501073A1 (de) | 1996-08-01 |
CA2185572C (en) | 2002-09-03 |
DE59602371D1 (de) | 1999-08-12 |
CA2185572A1 (en) | 1996-07-25 |
US5760888A (en) | 1998-06-02 |
EP0750735B1 (de) | 1999-07-07 |
EP0750735A1 (de) | 1997-01-02 |
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