In:
e-Journal of Nondestructive Testing, NDT.net GmbH & Co. KG, Vol. 27, No. 3 ( 2022-03)
Abstract:
Today, Computed Tomography is becoming increasingly important as a non-destructive testing technique in industry. The advantages of evaluating 3D information are manifold and system costs have fallen in recent years. However, these systems suffer from the disadvantage that performing a measurement is more complex and error-prone than pure radioscopic testing. Thus, users with more skill and experience are needed to get the most out of the scan. Nowadays, the process of parametrizing the CT scan is often completely manual and mostly performed by inspection engineers due to the high number of available parameters. These are spatial resolution, magnification, object and detector distances, number of projections and, most importantly, positioning of the specimen on the turntable. Choosing appropriate parameters is not trivial due to the interplay between required image quality and scan time. So, identifying optimal parameters can be a major challenge. The main goal of the scan planning is to solve the scan task dependably, process-safely if applicable, and efficiently with minimal investment of time. Simulation-based determination of the optimal parameters can enable objective parameters to be obtained that are less depended on expert users. This is especially important when a wide variety of objects need to be scanned. 3D printed parts, which can have a batch size of one under extreme conditions, serve as an example. The range of parts produced is extremely wide and complex, which leads to a complex configuration of the scan. Fraunhofer EZRT is developing software solutions to find an ideal scanning trajectory for a given scan task. For this purpose, CAD data of the part is used to simulate CT reconstructions and to evaluate the suitability of the parameters in focus of the task. For this, the image quality of the component, for metrological task e.g., and the detectability of faults inside the material, pores e.g., are considered. The user is given the ability to provide the parameter space especially with the regard to the geometry of the system. Also, the user can define quality criteria, pore sizes in different component locations e.g., which are considered in the optimization process. In the first step, those parameter sets are selected which have the best ratings on a projection basis. Subsequently, reconstructions are made on the remaining candidates, and these are evaluated. This approach saves computational time, the entire parameter space can be sampled, and a meaningful evaluation of the expected reconstruction can be performed.
Type of Medium:
Online Resource
ISSN:
1435-4934
Language:
Unknown
Publisher:
NDT.net GmbH & Co. KG
Publication Date:
2022
detail.hit.zdb_id:
2021293-8
