US5581483A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Measurement of shot peening coverage by correlation analysis of surface line data
Assignee: General Electric Co
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Filing: 1994-09-19
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Granted: 1996-12-03
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Expires: 2014-09-19
Abstract
Abstract A method of measuring shot peening coverage includes correlation analysis of surface line data. The method comprises the use of cross correlation of two or more parallel profile traces of a shot peened surface to produce a numeric indication of relative part coverage.
Inventors
- 👤 Robert A. Thompson
- 👤 Mark A. Tascillo
- 👤 Victor A. Skormin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:12
CPC Classifications
G; G06; G06T; G06T7/00; G06T7/60; G01; G01B; G01B21/00; G01B21/30; G06T2207/00; G06T2207/30; G06T2207/30108; G06T2207/30136
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
154 words
A method for measuring shot peening coverage using a correlation analysis of surface line data, said method comprising the steps of: selecting an area of shot peened surface treatment to analyze; obtaining at least two approximately parallel profile line traces from the surface treatment area to provide respective first and second data vectors thereof; determining the correlation function R xy j for said two data vectors according to the equation ##EQU3## where x 1 is said first data vector; x 2 is said second data vector; N is the number of points in each vector; j ranges from 0 to N/3; α 1 and α 2 represent standard deviation of said data vectors calculated using the following equations: ##EQU4## η 1 and η 2 represent mean values of said data vectors calculated using the following formulas: ##EQU5## finding the maximum peak to peak value of the correlation function for indicating said shot peening coverage.
Claim 2
Independent Claim
154 words
A method for measuring shot peening coverage using a correlation analysis of surface line data, said method comprising the steps of: selecting an area of shot peened surface treatment to analyze; obtaining at least two approximately parallel profile line traces from the surface treatment area to provide respective first and second data vectors thereof; determining the correlation function R xy j for said two data vectors according to the equation ##EQU3## where x 1 is said first data vector; x 2 is said second data vector; N is the number of points in each vector; j ranges from 0 to N/3; α 1 and α 2 represent standard deviation of said data vectors calculated using the following equations: ##EQU4## η 1 and η 2 represent mean values of said data vectors calculated using the following formulas: ##EQU5## finding the maximum peak to peak value of the correlation function for indicating said shot peening coverage.
Claim 3
Dependent Claim
20 words
A method in accordance with claim 1, wherein said step of obtaining profile line traces is completed using a profilometer.
Claim 4
Dependent Claim
32 words
A method in accordance with claim 1, wherein said surface treatment area includes machining marks, and said step of obtaining profile line traces is completed at a 30° angle to said marks.
Claim 5
Dependent Claim
36 words
A method in accordance with claim 1, wherein said surface treatment area includes machining marks, and said step of obtaining profile line traces is completed using a profilometer positioned at a 30° angle to said marks.
Claim 6
Independent Claim
85 words
A method for measuring shot peening coverage comprising: shot peening a workpiece having machining marks thereon; tracing said workpiece along a plurality of spaced apart lines to obtain a respective plurality of data vectors indicative of vertical displacement profiles thereof; cross correlating said plurality of data vectors to determine relative closeness between said data vectors as a function of distance between individual data points in said vectors; and determining a maximum peak to peak value of said cross correlation indicative of said shot peening coverage.
Claim 7
Independent Claim
85 words
A method for measuring shot peening coverage comprising: shot peening a workpiece having machining marks thereon; tracing said workpiece along a plurality of spaced apart lines to obtain a respective plurality of data vectors indicative of vertical displacement profiles thereof; cross correlating said plurality of data vectors to determine relative closeness between said data vectors as a function of distance between individual data points in said vectors; and determining a maximum peak to peak value of said cross correlation indicative of said shot peening coverage.
Claim 8
Dependent Claim
16 words
A method according to claim 5 wherein said tracing lines are substantially parallel to each other.
Claim 9
Dependent Claim
20 words
A method according to claim 6 wherein said tracing lines are disposed at an acute angle relative to said marks.
Claim 10
Dependent Claim
13 words
A method according to claim 7 wherein said acute angle is about 30°.
Claim 11
Dependent Claim
38 words
A method according to claim 7 wherein said shot peening effects craters on said workpiece, and said tracing lines are spaced apart from each other no less than twice the diameter of a largest one of said craters.
Claim 12
Dependent Claim
23 words
A method according to claim 7 wherein said cross correlating step is based on standard deviations and mean values of said data vectors.
Claim 13
Dependent Claim
36 words
A method according to claim 10 further comprising normalizing said cross correlation to a range between positive and negative one, with positive one representing full correlation, negative one representing negative correlation, and zero representing random correlation.
Claim 14
Dependent Claim
15 words
A method according to claim 7 further comprising two of said spaced apart tracing lines.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-12-03 | 2000-06-03 | 2000-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-12-03 | 2004-06-03 | 2004-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-12-03 | 2008-06-03 | 2008-12-03 | $7700.00 | Window Closed / Lapsed |