Patent ID: 11911914
Assignee: COGNEX CORPORATION
Field: Handling (Mechanical engineering)
Classification: CPC B  G | IPC B

Claim 0:
1. A system for performing hand-eye calibration of a vision system operating in conjunction with a robot manipulator that provides relative motion between a calibration object and a field of view (FOV) of a vision system camera defining an optical axis, comprising:
a vision system processor configured to operate a pre-calibration process that, performs a three-point calibration within the FOV and computes a rough transformation from an X-Y-Z coordinate space of the robot manipulator to a coordinate space of an acquired image of the vision system camera, and that, based upon the rough transformation, computes spatial points of features on the calibration object at a plurality of respective locations that are acceptable for performing the hand-eye calibration therewith;
wherein a field-of-view displacement effect, along at least one of an x-axis and a y-axis of the coordinate space of the acquired image, is induced in which a location of at least one of the robot manipulator and the calibration object is offset from the optical axis at a differential rate based upon the relative motion, as the robot manipulator and the calibration object are in rotation with respect to each other, and
wherein some of the features of calibration object move outside the FOV in at least one acquired image based upon the differential rate, and
wherein the three-point calibration is thereby performed with at least some of the features of the calibration object of at least one acquired image outside the FOV; and
a hand-eye calibration module that performs the hand-eye calibration using the spatial points computed during the pre-calibration process to guide the robot manipulator.