US 11,867,668 B2
Thickness correction for video extensometer systems and methods
Christian J. Hoehl, Dinslaken (DE); Adrian Charles Riddick, Medfield, MA (US); Michael Ashman, Natick, MA (US); and Nicholas Francisco Salerno, Brighton, MA (US)
Assigned to Illinois Tool Works Inc., Glenview, IL (US)
Filed by Illinois Tool Works Inc., Glenview, IL (US)
Filed on Jun. 29, 2020, as Appl. No. 16/915,586.
Prior Publication US 2021/0404929 A1, Dec. 30, 2021
Int. Cl. G06K 9/00 (2022.01); G01N 3/62 (2006.01); G06T 7/50 (2017.01); G01N 3/06 (2006.01); G06T 7/60 (2017.01); G06T 7/13 (2017.01)
CPC G01N 3/62 (2013.01) [G01N 3/068 (2013.01); G06T 7/13 (2017.01); G06T 7/50 (2017.01); G06T 7/60 (2013.01); G06T 2207/10028 (2013.01); G06T 2207/30204 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method for correcting for a variable thickness of a test specimen, the method comprising:
determining, via a processing system, a calibration distance between an imaging device and a calibration plane associated with a testing system;
receiving, via an interface, a thickness of a test specimen, the thickness corresponding to a distance between first and second surfaces of the test specimen, wherein the test specimen is arranged such that the first surface is a first distance from the imaging device and the second surface being a second distance from the imaging device;
calculating, via the processing system, a correction factor based in part on the calibration distance and a correction distance equivalent to a difference between a measurement plane and the calibration plane, wherein the correction distance is equivalent to one half of the thickness;
imaging, via the imaging device, one or more of a marking on the first surface of the test specimen or a silhouette of the test specimen to measure one or more characteristics of the test specimen, wherein the first surface of the testing specimen corresponds to the measurement plane, the measurement plane being offset from the calibration plane by a measurement distance; and
generating, via the processing system, one or more corrected characteristics by applying a correction factor to measurements of the one or more characteristics of the test specimen.