In-line NDT with X-Ray CT combining sample rotation and translation

Abstract

An alternative acquisition geometry for X-ray computed tomography (CT) is investigated as a solution to in-line non-destructive quality inspection in a high throughput production environment. The sample movement during acquisition combines a translation, typically horizontal, along one axis and a rotation about a second axis perpendicular to the first, and is shown to produce theoretically exact CT reconstructions. A methodology is presented to evaluate the design of a conveyor belt implementation for this acquisition scheme, investigating the trade-off between reconstruction quality and throughput. The methodology was applied in both a simulated version and an experimental mock-up of the conveyor belt implementation for a specific food sample, but can be extrapolated to any type of sample. Throughput, for the food sample, is predicted to be in a practically usable range of up to 5 samples per second. As a general conclusion, higher throughput can be reached with larger inspection stations while maintaining image quality.

Four hundred years of cork imaging: New advances in the characterization of the cork structure

“…X-ray tomography is a high-performance technique that can be used to investigate the inner structure of cork stoppers in a non-destructive way. Although it is time consuming when high resolution is required, it is noteworthy that there has been progress in X-ray tomography toward faster and in-line applications 32 . Even if the cell structure can also be assessed using this technique (limited to the hundred micrometer scale), other imaging techniques are used to study more accurately the cells that compose the phellem and the lenticels.…”

Neural network Hilbert transform based filtered backprojection for fast inline x-ray inspection

“…In the hFBP algorithm, the differential of the Hilbert transform of the projection data is backprojected onto the reconstruction plane to create the reconstructed image. In this paper, the hFBP is first adapted for an inline acquisition geometry [18][19][20] in section 2.1. Next, position-and angle-independent filters are derived in section 2.2, to form the NN-hFBP reconstruction.…”

“…To test the performance on real x-ray data, a mock-up was built for an inline scanning environment where the sample rotates and translates at the same time, closely mimicking an inline environment with a conveyor belt [20]. Specifications of the scanning geometry are given in table 1.…”

“…Recently, we introduced an alternative solution to the angular range problem by adding a rotation of the sample around an axis perpendicular to the conveyor belt [18][19][20], which largely solves missing wedge artefacts. Nevertheless, even in this scanning geometry the number of projections must be kept small to keep the reconstruction time limited, which may lead to undersampling artefacts.…”

Assessment of bruise volumes in apples using X-ray computed tomography

“…Additionally, such a study could provide valuable insight into the biology of bruise progression. Furthermore, it should be investigated whether with the recent developments in inline X-ray inspection Schryver et al, 2016), a sufficiently high acquisition and reconstruction speed is feasible for inline detection of bruises.…”