Cognex Corporation

Cognex Technology and Investment Corporation

Gang Liu

David J Michael

Lei Wang

Lowell D Jacobson

Aaron S Wallack

Guruprasad Shivaram

Cyril C Marrion

David Y Li

John W Schwab

Hongwei Zhu

Robert A Wolff

John McGarry

Ben R Carey

Nickolas James Mullan

Andrew Parrett

Ali Moghaddam Zadeh

Ruibing Wang

James Clark

Caleb Spear

This invention provides a system and method that performs 3D imaging of a complex object, where image data is likely lost. Available 3D image data, in combination with an absence/loss of image data, allows computation of x, y and z dimensions. Absence/loss of data is assumed to be just another type of image data, and represents the presence of something that has prevented accurate data from being generated in the subject image. Segments of data can be connected to areas of absent data and generate a maximum bounding box. The shadow that this object generates can be represented as negative or missing data, but is not representative of the physical object. The height from the positive data, the object shadow size based on that height, the location in the FOV, and the ray angles that generate the images, are estimated and the object shadow size is removed from the result.

Composite three-dimensional blob tool and method for operating the same

This invention provides an easy-to-manufacture, easy-to-analyze calibration object which combines measurable and repeatable, but not necessarily accurate, 3D features&#x2014;such as a two-sided calibration object/target in (e.g.) the form of a frustum, with a pair of accurate and measurable features, more particularly parallel faces separated by a precise specified thickness, so as to provide for simple field calibration of opposite-facing DS sensors. Illustratively, a composite calibration object can be constructed, which includes the two-sided frustum that has been sandblasted and anodized (to provide measurable, repeatable features), with a flange whose above/below parallel surfaces have been ground to a precise specified thickness. The 3D corner positions of the two-sided frustum are used to calibrate the two sensors in X and Y, but cannot establish absolute Z without accurate information about the thickness of the two-sided frustum; the flange provides the absolute Z information.

System and method for calibrating a plurality of 3D sensors with respect to a motion conveyance

This invention provides a system and method for generating camera calibrations for a vision system camera along three discrete planes in a 3D volume space that uses at least two (e.g. parallel) object planes at different known heights. For any third (e.g. parallel) plane of a specified height, the system and method then automatically generates calibration data for the camera by interpolating/extrapolating from the first two calibrations. This alleviates the need to set the calibration object at more than two heights, speeding the calibration process and simplifying the user's calibration setup, and also allowing interpolation/extrapolation to heights that are space-constrained, and not readily accessible by a calibration object. The calibration plate can be calibrated at each height using a full 2D hand-eye calibration, or using a hand-eye calibration at the first height and then at a second height with translation to a known position along the height (e.g. Z) direction.

System and method for calibration of machine vision cameras along at least three discrete planes

A system and method for three dimensional (3D) vision inspection using a 3D vision system. The system and method comprising acquiring at least one 3D image of a 3D object using the 3D vision system, using the 3D vision system; extracting a 3D visible runtime mask of the 3D image; using the 3D vision system, comparing the 3D runtime visible mask to a 3D reference visible mask; and, using the 3D vision system, determining if a difference of pixels exists between the 3D runtime visible mask and the 3D reference visible mask.

Using 3D vision for automated industrial inspection

A vision-based manipulations system can be configured for, and can be operated with methods including, performing hand-eye calibrations at multiple workstations of the system, performing a cross-station calibration for the system, and determining relationships between the hand-eye calibrations and the cross-station calibration. In some embodiments, the system can be used to move a work object between the workstations based on the cross-station calibration.

Calibration and operation of vision-based manipulation systems

A vision system capable of performing run-time 3D calibration includes a mount configured to hold an object, the mount including a 3D calibration structure; a camera; a motion stage coupled with the mount or the camera; and a computing device configured to perform operations including: acquiring images from the camera when the mount is in respective predetermined orientations relative to the camera, each of the acquired images including a representation of at least a portion of the object and at least a portion of the 3D calibration structure that are concurrently in a field of view of the camera; performing at least an adjustment of a 3D calibration for each of the acquired images based on information relating to the 3D calibration structure as imaged in the acquired images; and determining 3D positions, dimensions or both of one or more features of the object.

Calibration for vision system

This invention provides a system and method for hand-eye calibration of a vision system using an object under manufacture having at least one feature. The feature can be a linear feature and the object moves in at least one degree of freedom in translation or rotation on a motion stage. The system further comprises at least a first vision system camera and vision processor. The first vision system camera is arranged to acquire an image of the first linear feature on the object under manufacture and to track motion of the first linear feature in response to moving of the motion stage in at least one degree of translation. The first linear feature is identified in at least two different positions along a plane. The system computes a mapping between pixel positions in a pixel coordinate system of the first camera and physical positions in a motion coordinate system based upon locations of the at least two positions.

System and method for performing vision system planar hand-eye calibration from straight line features

Described are methods, systems, and apparatus, including computer program products for calibrating machine vision systems. A system includes: one or more cameras; a motion rendering device; and a calibration module. The calibration module is configured to acquire, from a first camera of the one or more cameras, a plurality of images of a calibration target comprising a calibration pattern that provides a plurality of calibration features; extract calibration features of the plurality of calibration features from the plurality of images, wherein physical positions of the plurality of calibration features are in a calibration target length unit associated with the calibration target; determine a ratio between the calibration target length unit and a motion rendering device length unit associated with the motion rendering device; and provide a first calibration for the first camera based on the ratio.

Machine vision system calibration using inaccurate calibration targets

A system and method for automated determination of position and movement of a contact lens with respect to a subject wearer's eye based upon a complimentary pair of images, acquired in rapid succession, in which one image of the pair is acquired using light that allows viewing of the pupil and/or limbus through the lens and the other image is acquired using light that is absorbed by the lens to generate an opaque image with a defined edge relative to the surrounding sclera. The images of the pair are acquired in close enough temporal proximity to ensure that eye movement in the interval therebetween is insignificant and both images are in the same approximate reference frame. Thus, the location of the pupil and limbus in one image can be accurately compared with the location of the contact lens edge in the other image.

System and method for automatically tracking a contact lens in a wearer's eye

Described are computer-based methods and apparatuses, including computer program products, for aligning a wafer for fabrication. A first image of a first portion of a wafer is received from a first image capturing device. A second image of a second portion of the wafer is received from a second image capturing device, wherein an image capturing device transform defines a first relationship between the first image capturing device and the second image capturing device. A first fiducial pattern in the first image and a second fiducial pattern in the second image are identified, based on the image capturing device transform, a fiducial transform that defines, based on a specification for the wafer, a second relationship between the first fiducial pattern and the second fiducial pattern, and a threshold value configured to identify low contrast fiducial patterns on wafers. An alignment of the wafer is determined based on the identified first and second fiducial patterns.

System and method for aligning a wafer for fabrication

This invention provides a system and method for automatic (non-manual) calibration of one or more cameras employs a tessellating calibration plate having a checkerboard tile pattern and a plurality of 2D codes embedded within the checkerboard pattern. Each 2D code encodes the (X,Y) coordinates that identify tile calibration feature locations in the pattern, and the remaining, surrounding tiles allow measurement of the corner positions as calibration features. One or more vision system camera(s) can be calibrated to a single coordinate system automatically. During calibration, an image of at least a portion of a calibration plate is acquired, the encoded data is decoded for at least one 2D code within the field of view of each camera and then the position of the field of view is determined on the calibration plate for each camera using the 2D code data and the checkerboard tile pattern.

System, method and calibration plate employing embedded 2D data codes as self-positioning fiducials

A system and method for generating golden template images in a vision system to inspect an acquired runtime image of an object with a multi-layer printed pattern is provided. The system and method performs a registration process on runtime images using registration models each trained on respective canonical layer mask images, and outputting poses. Based upon the poses, warped layer masks are generated. Combination masks are computed based upon differing combinations of the warped layer masks. Intensity values for pixels of the foreground regions for the combination masks are estimated. The estimated intensity values are then blended associated with the combination masks to generate a golden template image. This golden template image can be used to compare with a runtime image. An exemplary application of this system and method is in print inspection on flat and non-flat surfaces.

System and method for producing synthetic golden template image for vision system inspection of multi-layer patterns

An apparatus for associating codes on parts with part spaces on a conveyor wherein each part has a leading edge and a trailing edge that define a part space and each part is to be marked with at least one code, the apparatus comprising an area scan camera having a two dimensional field of view (FOV), the camera supported adjacent the conveyor so that parts conveyed by the conveyor pass through the FOV, a processor linked to the area scan camera, the processor programmed to perform the steps of receiving images from the area scan camera, identifying the locations of codes on parts in at least one of the images wherein a code located is a located code, identifying the locations of leading and trailing edges of parts wherein the leading and trailing edges define part spaces and associating each located code with a part space that includes the location of the located code.

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Natick, MA, United States of America

Gang Liu