A CCD camera mounted on a manufacturing part inspection workstation is calibrated for measuring 3D part geometry. It is calibrated by using computer algorithms to analyze data collected from a specially designed calibration image pattern. The calibration image used is a black and white checkerboard pattern. A commonly used camera calibration procedure is used to analyze the image data of the checkerboard calibration image. A camera model is obtained which contains intrinsic parameters representing the characteristic ...
Read More
A CCD camera mounted on a manufacturing part inspection workstation is calibrated for measuring 3D part geometry. It is calibrated by using computer algorithms to analyze data collected from a specially designed calibration image pattern. The calibration image used is a black and white checkerboard pattern. A commonly used camera calibration procedure is used to analyze the image data of the checkerboard calibration image. A camera model is obtained which contains intrinsic parameters representing the characteristic properties of the camera. The calibration is proven to result in a sub-pixel accuracy. A machine-part test specimen is chosen to demonstrate the accuracy of application of the camera model to predict geometrical feature locations of usual manufacturing parts. As a first trial, the experimental test shows that an accuracy on the order of 1 mm is easily attainable in predicting the feature locations, with the part being placed at a distance about 45 cm from the camera. Depending on the applications, special optical lens assembly may be designed to attach on the CCD camera and higher measurement accuracy of the feature locations may be obtained.
Read Less
