HIGH-PRECISION X-RAY STEREO FOR AUTOMATED 3-D CAD-BASED INSPECTION

An important challenge in industrial metrology is to provide rapid mea surement of critical three-dimensional (3-D) internal object geometry for either inspecting high volume parts or controlling a machining pro cess, Existing metrological techniques are typically too slow to meet this need or can not measure small features with high precision. In th is paper, we present a new method that achieves fast, accurate, intern al 3-D geometry measurement based on 3-D reconstruction from a few X-r ay views of a part, Our approach utilizes an accurate camera model for the X-ray sensor, calibration using in situ ground truth and geometry -guided X-ray feature extraction to achieve this goal and has been ful ly implemented in a prototype 3-D measurement system, We describe a no vel application of the system to CAD-based verification of drilled hol e positioning. Experimental results are given to illustrate the precis ion of the system and 3-D measurement on real industrial parts.