Line scan calibration method and apparatus

摘要

A method and apparatus for assessing at least one of motion linearity of a motion stage, stage motion straightness of a motion stage, image capture repeatability of a motion stage and camera and accuracy of a calibration plate used to assess motion stage characteristics, the method including using a line scan camera to generate two dimensional images of a calibration plate having a plurality imageable features thereon, examining the images to identify actual coordinates of the imageable features and using the actual coordinates to assess linearity, straightness, repeatability and/or plate accuracy.

主权项

1. A method for assessing motion linearity of a motion stage for a machine-vision system, the method for use with a line scan camera having a field of view (FOV), where the motion stage includes a moveable platform positioned with respect to the camera so that the platform travels through the camera FOV along a motion stage trajectory, the method comprising the steps of:
providing a calibration plate that includes at least four imageable features, the calibration plate being supported on the moveable platform; using the line scan camera to obtain data for generating a first two dimensional image of the calibration plate as the motion stage moves the calibration plate through the camera field of view along the motion stage trajectory; and running a processor programmed to perform the steps of: examining the first obtained image to identify an actual Y coordinate for each of the at least four imageable features in the first image; and processing linear equations including the actual Y coordinates of each of the at least four imageable features to assess stage motion linearity, stage motion linearity indicating, at least in part, a degree of constancy of stage motion.