Computed Tomography Helical Scanning for
Dimensional Metrology: Evaluation of Measurement
Publication: Publication Date: 1 July 2016Testing Method:
In industrial X-ray computed tomography, it is
frequently necessary to scan long objects that
exceed the dimensions of the detector, while
meeting dimensional accuracy requirements (for
example, in automotive and aerospace fields).
Conventional scans using circular trajectories face
limits when dealing with internal and complex
features on elongated work pieces. To this extent
helical scanning is a valuable solution that also
enables obtaining a strong improvement on image
quality, eliminating the cone beam artifacts that
characterize conventional scans. To use helical
scanning for dimensional quality control, the
assessment of metrological performances is
needed. In this work, metrological performances
for helical scanning are investigated and compared
with those of conventional circular scans.
Repeated helical scans are performed to investigate
the influence of main helical scans parameters
when performing dimensional measurements.
Experimental results show that helical scanning,
with appropriate scan parameters, performs better
than traditional circular scans with a strong
improvement on image quality.
- Bartscher, M., O. Sato, F. Härtig, and U. Neuschaefer-Rube, “Current State of Standardization in the Field of Dimensional Computed Tomography,” Measurement Science and Technology, Vol. 25, No. 6, 2014.
- Buzug, T.M., Computed Tomography: From Photon Statistics to Modern Cone-beam computed tomography, Springer, Berlin, Germany, 2008.
- Carmignato, S., D. Dreossi, L. Mancini, F. Marinello, G. Tromba, and E. Savio, “Testing of X-ray Microtomography Systems using a Traceable Geometrical Standard,” Measurement Science and Technology, Vol. 20, No. 8, 2009.
- Carmignato, S., and E. Savio, “Traceable Volume Measurements using Coordinate Measuring Systems,” CIRP Annals – Manufacturing Technology, Vol. 60, No. 1, 2011, pp. 519–522.
- De Chiffre, L., S. Carmignato, J.-P. Kruth, R. Schmitt, and A. Weckenmann, “Industrial Applications of Computed Tomography,” CIRP Annals – Manufacturing Technology, Vol. 63, No. 2, 2014, pp. 655–677.
- Feldkamp, L.A., L.C. Davis, and J.W. Kress, “Practical Cone-beam Algorithm,” Journal of the Optical Society of America A, Vol. 1, No. 6, 1984, pp. 612–619.
- Hiller, J., S. Kasperl, T. Schön, S. Schröpfer, and D. Weiss, “Comparison of Probing Error in Dimensional Measurement by Means of 3D Computed Tomography with Circular and Helical Sampling,” 2nd International Symposium on NDT in Aerospace, Hamburg, Germany, 22–24 November 2010.
- Hsieh, J., “A Practical Cone Beam Artifact Correction Algorithm,” IEEE Nuclear Science Symposium Conference Record, Vol. 2, 15–20 October 2000, pp. 15/71–15/74.
- ISO, ISO 10360-2: Geometrical Product Specifications (GPS) – Acceptance and Reverification Tests for Coordinate Measuring Machines (CMM) – Part 2: CMMs used for Measuring Linear Dimensions, International Organization for Standardization, Geneva, Switzerland, 2010.
- Kruth, J.P., M. Bartscher, S. Carmignato, R. Schmitt, L. De Chiffre, and A. Weckenmann, “Computed Tomography for Dimensional Metrology,” CIRP Annals – Manufacturing Technology, Vol. 60, No. 2, 2011, pp. 821–842.
- Marinello, F., E. Savio, S. Carmignato, and L. De Chiffre, “Calibration Artefact for the Microscale with High Aspect Ratio: The Fiber Gauge,” CIRP Annals – Manufacturing Technology, Vol. 57, No. 1, 2008, pp. 497–500.
- Muders, J., J. Hesser, A. Lachner, and C. Reinhart, “Accuracy Evaluation and Exploration of Measurement Uncertainty for Exact Helical Cone Beam Reconstruction using Katsevich Filtered Backprojection in Comparison to Circular Feldkamp Reconstruction with Respect to Industrial CT Metrology,” Proceedings of the International Symposium on Digital Industrial
- Radiology and Computed Tomography, Berlin, Germany, 20–22 June 2011, pp. 1–8.
- Smith, B.D., “Image Reconstruction from Cone-beam Projections: Necessary and Sufficient Conditions and Reconstruction Methods,” IEEE Transactions on Medical Imaging, Vol. 4, No. 1, 1985, pp. 14–25.
- VDI, VDI/VDE 2630, Part 1.3, Computed Tomography in Dimensional Measurement – Guideline for the Application of DIN EN ISO 10360 for Coordinate Measurement Machines with CT Sensors, Verein Deutscher Ingenieure, Dusseldorf, Germany, 2011.
- Wang, G., T.H. Lin, and P.C. Cheng, “Error Analysis on a Generalized Feldkamp’s Cone?beam Computed Tomography Algorithm,” Scanning, Vol. 17, No. 6, 1995, pp. 361–370.
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