X-ray metrology for quality assurance

There is considerable current interest in deriving accurate dimensional measurements of the internal geometry of complex manufactured parts, particularly castings. This paper describes an approach to the reconstruction of 3D part geometry from multiple digital X-ray images. A novel method for radiographic stereo is described which takes into account the special imaging geometry of the digital X-ray sensor modeled by a linear moving array, or pushbroom, camera. The 3D reconstruction algorithm employs a nominal geometric model which is perturbed by X-ray image constraints. Manufacturing applications are discussed and illustrated by experimental results on synthetic phantoms and actual casting images