The work carried out under the Marie Skłodowska Curie Actions Individual Fellowship (MSCA-IF) FlexCT project under grant agreement 752672, henceforth ‘the project’, advances the state-of-the-art in X-ray computed tomography (CT). The research performed in the project resulted in the development of dedicated procedures that can be easily implemented by users of CT to achieve high accuracy measurements by reducing the effects of instrument misalignments.
A method for the calibration of CT instrument misalignments was developed and applied to the measurement of simulated and experimental instrument geometries. The results are shown to be robust under diverse implementations and for various magnitudes of instrument misalignments. The implementation of the geometrical calibration procedure on simulated instrument geometries is described in more detail in [P3], while the implementation on an experimental instrument is described in [P4]. A graphical user interface has been created for implementing the geometrical calibration procedure in a user-friendly environment.
A software correction method was developed to compensate for the measured instrument misalignments. The compensation procedure consisted of adapting the tomographic reconstruction algorithm to the actual (measured) instrument geometry. Implementation of the software correction method on simulated instrument misalignments is described in [P5], while the implementation on an experimental instrument is described in [P6].
The procedures for geometrical calibration and software correction are made available to users of CT instruments by way of MATLAB scripts. Several dissemination activities were organized to communicate the results of the work, namely a short lecture to an external company and two conference seminars. The combination of the geometrical calibration and software correction methodologies were combined into a full CT measurement pipeline, which was described in [P2]. Other research related to the quality of dimensional measurements by CT was also performed under the scope of the project. The sensitivity of CT dimensional measurements to error motions of the sample rotation stage was investigated and the results were presented at a conference [P1]. The project has allowed the researcher has gain valuable experience in project management, in organizing seminars, and in establishing collaboration with external parties. Furthermore, the hosting of the researcher at Materialise NV has provided him with exposure to additive manufacturing, a field of research that is in high demand given its potential in the manufacturing industry. The researcher contributed to the establishment of formal collaboration between Materialise NV and Volume Graphics GmbH, a company dedicated to software for analysis of CT data. The collaboration was formalized in an official announcement at FormNext, a leading exhibition of additive manufacturing technology and capabilities. Furthermore, the researcher collaborated with experts at Materialise NV and at KU Leuven in the CT inspection of plastic and metal additively manufactured components [P7].
Publications from action:
[P1] Ferrucci M et al. 2018 Sensitivity of CT dimensional measurements to rotation stage errors 8th Conference on Industrial Computed Tomography (Wels, Austria)
[P2] Dewulf W, Ferrucci M, et al. 2018 Enhanced dimensional measurement by fast determination and compensation of geometrical misalignments of X-ray computed tomography instruments CIRP Annals 67 (1), 523-526
[P3] Ferrucci M et al. 2018 Measurement of the X-ray computed tomography instrument geometry by minimization of reprojection errors—Implementation on simulated data Precision Engineering 54, 7-20
[P4] Ferrucci M et al. 2018 Measurement of the X-ray computed tomography instrument geometry by minimization of reprojection errors—Implementation on experimental data Precision Engineering 54, 107-117
[P5] Ametova E, Ferrucci M, et al. 2018 Software-based compensation of instrument misalignments for X-ray computed tomography dimensional metrology Precision Engineering 54, 233-242
[P6] Ametova E, Ferrucci M, et al. 2018 Software-based compensation of CT instrument misalignments – experimental study 9th Conference on Industrial Computed Tomography (Padova, Italy)
[P7] Yang L, Mertens R, Ferrucci M, et al. 2019 Continuous graded Gyroid cellular structures fabricated by selective laser melting: Design, manufacturing and mechanical properties Materials & Design 162, 394-404
