Cognex Corporation

Cognex Technology and Investment Corporation

Robert A Wolff

Aaron S Wallack

Mikhail Akopyan

William M Silver

Sanjay J Nichani

Michael C Moed

Robert Tremblay

Willard P Foster

David J Michael

David A Schatz

Lowell D Jacobson

Hongwei Zhu

Marcus Große

Ruibing Wang

Thomas Penny

Cyril C Marrion

Gang Liu

Raymond A Fix

Ali Moghaddam Zadeh

David R King

Matthew R Reome

David Shatz

Gene Halbrooks

Ronald E Dynneson

Benjamin D Klass

This invention provides a system and method for determining the location and characteristics of certain surface features that comprises elevated or depressed regions with respect to a smooth surrounding surface on an object. A filter acts on a range image of the scene. A filter defines an annulus or other perimeter shape around each pixel in which a best-fit surface is established. A normal to the pixel allows derivation of local displacement height. The displacement height is used to establish a height deviation image of the object, with which bumps, dents or other height-displacement features can be determined. The bump filter can be used to locate regions on a surface with minimal irregularities by mapping such irregularities to a grid and then thresholding the grid to generate a cost function. Regions with a minimal cost are acceptable candidates for application of labels and other items in which a smooth surface is desirable.

System and method for determining 3D surface features and irregularities on an object

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

The techniques described herein relate to methods, apparatus, and computer readable media configured to determine parameters for image acquisition. One or more image sensors are each arranged to capture a set of images of a scene, and each image sensor comprises a set of adjustable imaging parameters. A projector is configured to project a moving pattern on the scene, wherein the projector comprises a set of adjustable projector parameters. The set of adjustable projector parameters and the set of adjustable imaging parameters are determined, based on a set of one or more constraints, to reduce noise in 3D data generated based on the set of images.

Methods and apparatus for optimizing image acquisition of objects subject to illumination patterns

This invention provides a system for measuring displacement of an object surface having a displacement sensor that projects a line on the object surface and receives light from the projected line at an imager in a manner defines a plurality of displacement values in a height direction. A vision system processor operates on rows of imager pixels to determine a laser line center in columns of imager pixels in each of a plurality of regions of interest. Each region of interest defines a plurality of rows that correspond with expected locations of the projected line on the object surface. A GUI can be used to establish the regions. In further embodiments, the system generates grayscale images with the imager. These grayscale images can be compared to a generated height image to compensate for contrast-induced false height readings. Imager pixels can be compared to a reference voltage to locate the line.

System and method for efficient surface measurement using a laser displacement sensor

This invention provides a system and method for reading and decoding ID features located on a surface of a curved, sloped and/or annular object, such as a tire moving on a conveyor. A plurality of 3D sensors are operatively connected to a vision system processor. The sensors are calibrated by calibration parameters to generate a stitched-together 3D image of a field of view in a common coordinate space. A motion conveyance (e.g. a conveyor) causes the object and the 3D sensors to move in relative motion, and the conveyance provides motion information to the vision system processor. An ID finder locates ID features within a version of the 3D image and a decoder (e.g. an OCR reader) generates data from the ID features. The ID finder can locate a trained portion of the ID and the search for variable code elements at a known orientation relative to the trained portion.

System and method for reading and decoding ID codes on a curved, sloped and/or annular object

This invention provides a system and method for estimating the time of a set of pulses based upon a plurality of position measurements of a moving object provided by a non-contacting sensor, such as a one-dimensional optical sensor that tracks movements of object features and reports position measurements with respect to time. Position measurements determine the estimated velocity. The velocity and position measurement allow the timing of a next pulse to be updated, based upon the time of the previous pulse. The pulse is output at the time of the last updated time before the first new position measurement received after the estimated pulse output time. The system allows pulses to be precisely delivered at predetermined motion distances. Where the distance is too short for the measurement rate, the system compares estimated pulse times to clock-generated pulse times and updates the clock-generated pulse times based upon the difference.

System and method for providing distance-based pulses relative to motion of a surface scanned by a vision system

Enhanced portal security is provided through stereoscopy, including a stereo door sensor for detecting and optionally preventing access violations, such as piggybacking and tailgating. A portal security system can include a 3D imaging system that generates a target volume from plural 2D images of a field of view about a portal; and a processor that detects and tracks people candidates moving through the target volume to detect a portal access event.

Method and system for enhanced portal security through stereoscopy

This invention overcomes the disadvantages of the prior art by providing a human/machine interface (HMI) for use with machine vision systems (MVSs) that provides the machine vision system processing functionality at the sensor end of the system, and uses a communication interface to exchange control, image and analysis information with a standardized, preferably portable device that can be removed from the MVS during runtime. In an illustrative embodiment, this portable device can be a web-browser equipped computer (handheld, laptop or fixed PC) or a Personal Digital Assistant (PDA). The communication interface on the sensor-end of the system is adapted to communicate over a cable or wireless communication link (for example infrared (IR) or radio frequency (RF)), with a corresponding communication interface in the portable device. The data communicated over the interconnect or link is formatted so that it is read at a data speed and level of resolution (pixel count) that is appropriate to the portable device by use of an image processor at the sensor end.

Human/machine interface for a machine vision sensor and method for installing and operating the same

A two-dimensional (2-D) machine-vision safety-solution involving a method and apparatus for performing high-integrity, high efficiency machine vision. A known structured lighting texture pattern is projected upon a target area. A model image of the pattern on an empty target field is stored during an initial training step. The machine vision safety solution digitally interprets a camera image of the light reflected by the objects in the target area to detect and characterize a pattern in the image. The pattern characterization is then processed to determine if a distortion of the characterization factors is larger than a predetermined threshold, and results in an alarm condition.

Video safety detector with projected pattern

A hub that controls the acquisition of images from a plurality of image sources utilizes image acquisition logic that selectively applies a first set of control signals (e.g., &ldquo;shutter&rdquo; signals) to imaging devices, causing them to acquire images. The logic applies a second set of control signals (e.g., &ldquo;readout&rdquo; signals) to the devices, causing them to output the images to the hub. Those images are transferred by the hub to a host over an isochronous communications medium.

Control methods and apparatus for coupling multiple image acquisition devices to a digital data processor

A two-dimensional (2-D) machine-vision safety-solution involving a method and apparatus for performing high-integrity, high efficiency machine vision. The machine vision safety solution digitally filters a configurable number of time-sequenced images of a viewed area to create a filtered image. A textured background is used as a static target and viewed under ambient light, or alternatively a texture is observed under IR light. An artificial texture can be created with a particularized pattern. Each new image is then compared to the previously created model and a pixel-oriented difference image is calculated. The difference image is then processed for segmentation features attributable to an intruder object. For segmentation results that exceed a predetermined threshold, an alarm condition is set.

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Lexington, MA, United States of America

Robert A Wolff