Iterative computed tomography reconstruction algorithms for robotized inspection
Résumé
Robotized Computed Tomography (CT) inspection is one of the acknowledged new trends in X-ray Non Destructive Evaluation (NDE) since it allows more flexibility in the acquisition trajectory and therefore a valued adaptability to object and environment constraints. In this context, we are developing at CEA List an advanced platform consisting of two robots equipped respectively with a micro-focus X-ray tube and a flat panel detector. In order to perform CT inspection with such equipment, it is essential to deal with the main challenge brought by this robotized inspection, which is the angular limitation of the trajectory. Such limited-angle trajectory makes the classical analytic reconstruction algorithms inappropriate and requires the use of 3D iterative reconstruction algorithms. Two iterative algorithms are compared in this work, the wellknown Simultaneous Algebraic Reconstruction Technique (SART) and the Discrete Algebraic Reconstruction Technique (DART), which integrates prior knowledge on the object, to perform 3D reconstructions from a limited data set. Their performances are evaluated and both algorithms are applied on real data acquired with the robotic platform.
Mots clés
Algebra
Bridge decks
Computerized tomography
Image reconstruction
Inspection
Iterative methods
Tomography
Trajectories
X ray tubes
Discrete Algebraic Reconstruction Technique (DART)
Environment constraints
Iterative reconstruction algorithms
Micro-focus x-ray tubes
Non destructive evaluation
Reconstruction algorithms
Simultaneous algebraic reconstruction technique
Tomography reconstruction
Nondestructive examination