Patents by Inventor Tian Gan

Tian Gan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Simultaneous kinematic and hand-eye calibration
    Patent number: 10864639
    Abstract: Described are machine vision systems and methods for simultaneous kinematic and hand-eye calibration. A machine vision system includes a robot and a 3D sensor in communication with a control system. The control system is configured to move the robot to poses, and for each pose: capture a 3D image of calibration target features and robot joint angles. The control system is configured to obtain initial values for robot calibration parameters, and determine initial values for hand-eye calibration parameters based on the initial values for the robot calibration parameters, the 3D image, and joint angles. The control system is configured to determine final values for the hand-eye calibration parameters and robot calibration parameters by refining the hand-eye calibration parameters and robot calibration parameters to minimize a cost function.
    Type: Grant
    Filed: June 21, 2019
    Date of Patent: December 15, 2020
    Assignee: Cognex Corporation
    Inventors: Lifeng Liu, Cyril C. Marrion, Tian Gan, David Michael, Han Xiao
  • SIMULTANEOUS KINEMATIC AND HAND-EYE CALIBRATION
    Publication number: 20190308326
    Abstract: Described are machine vision systems and methods for simultaneous kinematic and hand-eye calibration. A machine vision system includes a robot and a 3D sensor in communication with a control system. The control system is configured to move the robot to poses, and for each pose: capture a 3D image of calibration target features and robot joint angles. The control system is configured to obtain initial values for robot calibration parameters, and determine initial values for hand-eye calibration parameters based on the initial values for the robot calibration parameters, the 3D image, and joint angles. The control system is configured to determine final values for the hand-eye calibration parameters and robot calibration parameters by refining the hand-eye calibration parameters and robot calibration parameters to minimize a cost function.
    Type: Application
    Filed: June 21, 2019
    Publication date: October 10, 2019
    Inventors: Lifeng Liu, Cyril C. Marrion, Tian Gan, David Michael, Han Xiao
  • Simultaneous Kinematic and Hand-Eye Calibration
    Publication number: 20190015991
    Abstract: Described are machine vision systems and methods for simultaneous kinematic and hand-eye calibration. A machine vision system includes a robot or motion stage and a camera in communication with a control system. The control system is configured to move the robot or motion stage to poses, and for each pose: capture an image of calibration target features and robot joint angles or motion stage encoder counts. The control system is configured to obtain initial values for robot or motion stage calibration parameters, and determine initial values for hand-eye calibration parameters based on the initial values for the robot or motion stage calibration parameters, the image, and joint angles or encoder counts. The control system is configured to determine final values for the hand-eye calibration parameters and robot or motion stage calibration parameters by refining the hand-eye calibration parameters and robot or motion stage calibration parameters to minimize a cost function.
    Type: Application
    Filed: September 17, 2018
    Publication date: January 17, 2019
    Inventors: Lifeng Liu, Cyril C. Marrion, Tian Gan
  • Simultaneous kinematic and hand-eye calibration
    Patent number: 10076842
    Abstract: Described are machine vision systems and methods for simultaneous kinematic and hand-eye calibration. A machine vision system includes a robot or motion stage and a camera in communication with a control system. The control system is configured to move the robot or motion stage to poses, and for each pose: capture an image of calibration target features and robot joint angles or motion stage encoder counts. The control system is configured to obtain initial values for robot or motion stage calibration parameters, and determine initial values for hand-eye calibration parameters based on the initial values for the robot or motion stage calibration parameters, the image, and joint angles or encoder counts. The control system is configured to determine final values for the hand-eye calibration parameters and robot or motion stage calibration parameters by refining the hand-eye calibration parameters and robot or motion stage calibration parameters to minimize a cost function.
    Type: Grant
    Filed: September 28, 2016
    Date of Patent: September 18, 2018
    Assignee: Cognex Corporation
    Inventors: Lifeng Liu, Cyril C. Marrion, Tian Gan
  • Simultaneous Kinematic and Hand-Eye Calibration
    Publication number: 20180089831
    Abstract: Described are machine vision systems and methods for simultaneous kinematic and hand-eye calibration. A machine vision system includes a robot or motion stage and a camera in communication with a control system. The control system is configured to move the robot or motion stage to poses, and for each pose: capture an image of calibration target features and robot joint angles or motion stage encoder counts. The control system is configured to obtain initial values for robot or motion stage calibration parameters, and determine initial values for hand-eye calibration parameters based on the initial values for the robot or motion stage calibration parameters, the image, and joint angles or encoder counts. The control system is configured to determine final values for the hand-eye calibration parameters and robot or motion stage calibration parameters by refining the hand-eye calibration parameters and robot or motion stage calibration parameters to minimize a cost function.
    Type: Application
    Filed: September 28, 2016
    Publication date: March 29, 2018
    Inventors: Lifeng Liu, Cyril C. Marrion, Tian Gan