Loading patent…
AssigneeGeneral Electric Company
InventorsVan-Duc Nguyen, Roderic Greene Collins, Victor Nzomigni, Donald Wagner Hamilton, Jr., Charles Vernon Stewart, Joseph Legrand Mundy
Estimating the term…
The present invention is directed to an imaging apparatus for examining an object having smooth surfaces to determine shape deformations in the surface of object. The imaging apparatus includes an imaging device for obtaining a scanned image of the object to be examined. A reference image of the object is stored in a memory. An image register is coupled to the imaging device and to the memory containing the reference image of the object. The image register stores patch information corresponding to both the reference image and the scanned image. A transformation estimator is coupled to the image register, and provides a transform for registering the scanned image to the reference image. A deformation estimator is coupled to the transformation estimator and to the image register. The deformation estimator is configured to utilize the transform and the patch information to determine shape deformations of the object.
A method of finding shape deformations in an object, the method comprising the steps of:
A storage medium encoded with machine-readable computer program code for modeling an object an object comprising instructions for causing a computer to implement a method comprising the steps of:
Dependencies are inferred from the claim text.
Drawings are temporarily unavailable. Open the PDF at USPTO
From the US filing history. Foreign family members aren’t listed.
Involving plural approaches, e.g. verification by template match; Resolving confusion among similar patterns, e.g. "O" versus "Q": coarse or fine…
Shutting-down of machines or engines, e.g. in emergency; Regulating, controlling, or safety means not otherwise provided for: arrangements for…
Topological mapping of higher dimensional structures onto lower dimensional surfaces: transforming surfaces of revolution to planar images, e.g.…
Image analysis: determination of transform parameters for the alignment of images, i.e. image registration
Term ended 15 Jul 2019 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
The present invention relates generally to a method and apparatus for finding shape deformations in objects having smooth surfaces and in particular, to a method and apparatus for finding shape deformations in airfoils by registering surface points on an airfoil to a computer assisted drawing (CAD) model and analyzing and displaying principal modes of surface deformation to a user.
Currently, automated inspection is performed on manufactured parts such as airfoils (e.g. turbine blades) to detect deformities in the part. For purposes of this specification, deformities are defined to be deformations in the shape of an object as compared to its ideal shape. In other words, deformations are deviations in shape or form of an object from its manufacturing specifications. Shape deformation can occur in a variety of modes (referred to herein as deformation modes). Deformation modes include, but are not limited to, skew, twist, scaling and translation. Forged blades, such as those for aircraft engines, are currently inspected for platform orientation, contour cross-section, bow and twist along stacking axis, thickness and chord length at given cross-sections. One method of inspecting for shape deformations in these deformation modes is through the use of specialized hard gages built out from micro-meters, calipers, and shims. The hard gages measure a plurality of defined contact points to characterize the blade that is used to detect defects. While the inspection of using the hard gages is fast, the hard gages provide only individual measurements at a few defined contact points.
In the alternative, blades can be fully scanned with coordinate measurement machines (commonly know as “CMMs”) that translate and rotate a probe to sample points on the blade surface. CMMs provide dense measurements of the sample points, however the time to scan a blade is relatively slow. Once the dense surface points are collected, software processes these points into deviations to the CAD model and analyzes the deviations in terms of process-based shape deformations. Current processing software, however, is relatively slow.
Referring now to the drawings wherein like elements are numbered alike in the several Figures:
FIG. 1 is a block diagram of an apparatus for finding shape deformations according to one embodiment of the present invention;
FIG. 2 is a flowchart of the method, embodying the present invention, of finding and displaying the deformation of an airfoil;
For purposes of this specification, the following definitions of terms are provided. An image is defined herein to be a collection of data representing properties, design specifications, or attributes of an object. For example, a data collection which represents the 3 spatial dimensions (x,y,z) of an object is an image of the object. When such data are obtained by measuring the object and storing the measurements in memory, the stored measured data is referred to herein as scanned image 15. The data comprising a Computer Assisted Drawing (CAD), or other engineering specifications in digitized format, relating to the shape of an object, are referred to herein as images of the object. CAD data comprising specifications for an object to which the object will be compared for purposes of flaw detection is referred to herein as a reference image.
An arrangement of data representing an image is referred to herein as an array. Each element of an array is referred to herein as a pixel. A pixel represents a measurement or property at a given position on the surface of the object being measured. For example, a pixel can represent measurements of the distance of the object from the measuring device.
Mapping is the process of relating pixels in one image to pixels in another image. One method of mapping is accomplished by fitting a function to control point locations. Control points are features located in the scanned image whose location on the object and its images are known. Control points may be located both in the scanned image and in the reference image.