IP Library Granted Patent US 7,899,573
Granted Patent B2
US 7,899,573 · App. 12/140,051 · Granted Mar 1, 2011

Non-contact method and system for inspecting a multi-faceted machine surface

Assignee: GM Global Technology Operations LLC
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Quick Facts
Patent No.
US 7,899,573
App. No.
12/140,051
Granted
Mar 1, 2011
Kind
B2
Abstract

A system and method for inspecting a machined surface. The method includes acquiring optical information of the machined surface from a predefined orientation. Further, the method includes comparing one or more parameters of the optical information with a corresponding one or more reference parameters. Furthermore, the method includes assessing a quality of the machined surface based on the comparison.

Claims (29)

1. A non-contact method for inspecting a multi-faceted machined surface, the method comprising:

acquiring optical information for a plurality of facets of the machined surface, wherein the optical information is acquired after reflection of an optical beam from a curved mirror;

comparing one or more parameters of the optical information with a corresponding one or more reference parameters; and

assessing the quality of the machined surface based on the comparison.

2. The method according to claim 1 wherein the optical information is acquired by one of a laser sensor, a digital camera, and a line-scan camera with LED lighting.

3. The method according to claim 2 wherein the optical information is a digital image of the machined surface, and wherein the one or more parameters are selected from the group comprising a location of one or more elements of the digital image, a linear dimension of the one or more elements of the digital image and an angular dimension of the one or more elements of the digital image.

4. The method according to claim 1 wherein the one or more parameters are selected from the group comprising an intensity of light reflected from the machined surface and a width of light reflected from the machined surface or parts thereof.

5. The method according to claim 1 wherein comparing one or more parameters includes processing the optical information to determine magnitudes of the one or more parameters and identifying a degree of co-relation between the magnitudes of the one or more parameters and corresponding magnitudes of the one or more reference parameters.

6. The method according to claim 1 wherein comparing one or more parameters is performed based on a computer based image processing script.

7. The method according to claim 1 wherein the facets of the machined surface include a valve seat of a cylinder head of an internal combustion (IC) engine, a valve deck of the cylinder head and a valve throat of the cylinder head.

8. A system for inspecting a multi-faceted machined surface, said system comprising:

at least one acquisition unit including a cylindrical mirror and being capable of acquiring optical information for a plurality of facets of the machined surface; and

a data processing unit including at least one comparison unit, said comparison unit being configured to compare the optical information with one or more pre-determined parameters of the machined surface, said data processing unit further including at least one assessing unit configured to assess the quality of the machined surface.

9. The method according to claim 1 wherein assessing the quality of the machined surface comprises identifying defects on the machined surface, and wherein the defects are selected from the group comprising a waviness of the machined surface, a chatter of the machined surface, a scratch on the machined surface and a burr on the machined surface.

10. A non-contact method for inspecting a multi-faceted machined surface, wherein the facets of the machined surface include a valve seat of a cylinder head of an internal combustion (IC) engine, a valve deck of the cylinder head and a valve throat of the cylinder head, the method comprising:

acquiring optical information for a plurality of facets of the machined surface, wherein the optical information is acquired after reflection of an optical beam from a cylindrical mirror;

identifying one or more parameters of the optical information;

processing the optical information to determine magnitudes of the one or more parameters;

determining a degree of co-relation between the magnitudes of the one or more parameters and corresponding magnitudes of the one or more reference parameters; and

assessing the quality of the surface based on the degree of co-relation.

11. The method according to claim 10 wherein the optical information is acquired by one of a laser sensor and a digital camera.

12. The method according to claim 11 wherein the optical information is a digital image of the machined surface, and wherein the one or more parameters are selected from the group comprising a location of one or more elements of the digital image, a linear dimension of the one or more elements of the digital image and an angular dimension of the one or more elements of the digital image.

13. The method according to claim 10 wherein the one or more parameters are selected from the group comprising an intensity of light reflected from the machined surface and a width of light reflected from the machined surface or parts thereof.

14. The method according to claim 10 wherein comparing one or more parameters is performed based on a computer based image processing script.

15. The system according to claim 8 wherein the facets of the machined surface include a valve seat of a cylinder head of an internal combustion (IC) engine, a valve deck of the cylinder head and a valve throat of the cylinder head.

16. The system according to claim 8 wherein the at least one acquisition unit includes a laser sensor or a digital camera.

17. The system according to claim 8 wherein the at least one comparison unit compares the optical information based on a computer-aided image processing script.

18. The system according to claim 8 further comprising an interface to facilitate at least one of an input to the system and render output from the system.

19. The method according to claim 8 wherein the curved mirror is cylindrical in shape.

Assignments (12)
RELEASE OF SECURITY INTEREST Recorded Nov 7, 2014
From: WILMINGTON TRUST COMPANY
To: GM GLOBAL TECHNOLOGY OPERATIONS LLC
Reel/Frame 034384/0758 →
CHANGE OF NAME Recorded Feb 10, 2011
From: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
To: GM GLOBAL TECHNOLOGY OPERATIONS LLC
Reel/Frame 025781/0211 →
SECURITY AGREEMENT Recorded Nov 8, 2010
From: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
To: WILMINGTON TRUST COMPANY
Reel/Frame 025324/0475 →
RELEASE OF SECURITY INTEREST Recorded Nov 5, 2010
From: UAW RETIREE MEDICAL BENEFITS TRUST
To: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Reel/Frame 025315/0001 →
RELEASE OF SECURITY INTEREST Recorded Nov 4, 2010
From: UNITED STATES DEPARTMENT OF THE TREASURY
To: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Reel/Frame 025245/0909 →
SECURITY AGREEMENT Recorded Aug 28, 2009
From: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
To: UAW RETIREE MEDICAL BENEFITS TRUST
Reel/Frame 023162/0187 →
SECURITY AGREEMENT Recorded Aug 27, 2009
From: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
To: UNITED STATES DEPARTMENT OF THE TREASURY
Reel/Frame 023156/0215 →
RELEASE OF SECURITY INTEREST Recorded Aug 21, 2009
From: UNITED STATES DEPARTMENT OF THE TREASURY
To: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Reel/Frame 023126/0914 →
RELEASE OF SECURITY INTEREST Recorded Aug 21, 2009
From: CITICORP USA, INC. AS AGENT FOR BANK PRIORITY SECURED PARTIES; CITICORP USA, INC. AS AGENT FOR HEDGE PRIORITY SECURED PARTIES
To: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Reel/Frame 023155/0769 →
SECURITY AGREEMENT Recorded Apr 16, 2009
From: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
To: CITICORP USA, INC. AS AGENT FOR BANK PRIORITY SECURED PARTIES; CITICORP USA, INC. AS AGENT FOR HEDGE PRIORITY SECURED PARTIES
Reel/Frame 022554/0538 →
SECURITY AGREEMENT Recorded Feb 4, 2009
From: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
To: UNITED STATES DEPARTMENT OF THE TREASURY
Reel/Frame 022201/0448 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 16, 2008
From: AGAPIOU, JOHN S.; STEINACKER, PHILLIP K.
To: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Reel/Frame 021102/0329 →
Continuity (1)
Related Publication 20090312863A1 · Dec 17, 2009