Method for spatial measurement of holes
First Claim
1. A method for measuring the location of a hole in a workpiece comprising the steps of:
- projecting feature lighting, characterized by substantially uniform illumination, upon said workpiece;
optically sensing said workpiece under said feature lighting to receive an image comprising comparatively light and dark areas indicative of the centroid of said hole;
projecting structured lighting, characterized by a predetermined geometric pattern of illumination, upon said workpiece;
optically sensing said workpiece under said structured lighting to receive an image comprising a reflected pattern defining a plane in which said hole is disposed; and
determining the geometric intersection of said plane and said centroid to thereby establish the real space location of said hole.
1 Assignment
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Accused Products
Abstract
The three-dimensional position of a hole through a workpiece is determined using back lighting or front lighting (feature lighting) to determine the centroid of the hole'"'"'s image in two-dimensional computer memory image space. The centroid determines a line of sight between the center of the hole'"'"'s image and the actual center of the hole in real space. Next a crosshair lighting pattern (structured lighting) is projected onto the plane of the workpiece in the neighborhood of the hole. From the reflected crosshair pattern an equation representing the plane containing the hole is determined in image space. The intersection of the plane equation and the line of sight is computed and the three-dimensional, real space position of the hole is determined for comparision with an ideal position established during calibration.
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Citations
25 Claims
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1. A method for measuring the location of a hole in a workpiece comprising the steps of:
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projecting feature lighting, characterized by substantially uniform illumination, upon said workpiece; optically sensing said workpiece under said feature lighting to receive an image comprising comparatively light and dark areas indicative of the centroid of said hole; projecting structured lighting, characterized by a predetermined geometric pattern of illumination, upon said workpiece; optically sensing said workpiece under said structured lighting to receive an image comprising a reflected pattern defining a plane in which said hole is disposed; and determining the geometric intersection of said plane and said centroid to thereby establish the real space location of said hole. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method for measuring the location of a hole in a workpiece comprising the steps of:
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projecting feature lighting, characterized by substantially uniform illumination, upon said workpiece; optically sensing said workpiece under said feature lighting to receive an image comprised comparatively light and dark areas indicative of the centroid of said hole in image space; from said centroid determining a line in real space which passes through the center of said hole in real space; projecting structured lighting, characterized by a predetermined geometric image of illumination, upon said workpiece to thereby produce a reflected image in image space; optically sensing said workpiece under said structured lighting to receive said reflected image being indicative of a plane in which said hole is disposed; and determining the real space location of said hole by determining the geometric intersection of said plane and said line. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15)
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16. A method for measuring the location of a hole in a workpiece comprising the steps of:
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predetermining a transformation between image space and real space; projecting feature lighting, characterized by substantially uniform illumination, upon said workpiece; optically sensing said workpiece under said feature lighting to receive an image comprising comparatively light and dark areas indicative of the centroid of said hole in image space; applying said predetermined transformation to said centroid to determine a line in real space which passes through the center of said hole in real space; projecting structured lighting, characterized by a predetermined geometric pattern of illumination, upon said workpiece; optically sensing said workpiece under said structured lighting to receive an image comprising a reflected image in image space indicative of the plane in which said hole is located; applying said predetermined transformation to said reflected image to determine the plane in which said hole is located; and determining the real space location of said hole by determining the geometric intersection of said plane and said line. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25)
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Specification