DigitalMaschinenbau und MechatronikZeitschriftenartikel
P. Müller, Jochen Hiller, Y. Dai, J. Andreasen, H. Hansen, L. Chiffre
Quantitative analysis of scaling error compensation methods in dimensional X-ray computed tomography
CIRP Journal of Manufacturing Science and Technology, vol. 10, no. August, pp. 68-76
2015
DOI: 10.1016/j.cirpj.2015.04.004
Abstract anzeigen
X-ray Computed Tomography (CT) has become an important technology for quality control of industrial components. As with other technologies, e.g., tactile coordinate measurements or optical measurements, CT is influenced by numerous quantities which may have negative impact on the accuracy and repeatability of dimensional and geometrical measurements. The aim of this paper is to discuss different methods for the correction of scaling errors and to quantify their influence on dimensional measurements. Scaling errors occur first and foremost in CT systems with no built-in compensation of positioning errors of the manipulator system (magnification axis). This article also introduces a new compensation method for scaling errors using a database of reference scaling factors and discusses its advantages and disadvantages. In total, three methods for the correction of scaling errors – using the CT ball plate, using calibrated features measured by CMM and using a database of reference values – are presented and applied within a case study. The investigation was performed on a dose engine component of an insulin pen, for which several dimensional measurands were defined. The component has a complex geometry and is made of brass, which makes its measurements with CT challenging. It is shown that each scaling error correction method results in different deviations between CT measurements and reference measurements from a CMM. Measurement uncertainties were estimated for each method, taking into consideration the contributions related to the applied correction method. The newly suggested approach using the database appeared to work well, indicating, that if the properties of a CT system under investigation are monitored using a reference object (ball bar in our case), a correction factor based on individual selected magnification factors can be applied for scaling error correction of any object, and thus no additional scanning of a reference object is needed.
Maschinenbau und MechatronikZeitschriftenartikel
P. Müller, Jochen Hiller, Y. Dai, J. Andreasen, H. Hansen, L. Chiffre
Estimation of measurement uncertainties in X-ray computed tomography metrology using the substitution method
CIRP Journal of Manufacturing Science and Technology, vol. 7, no. 3, pp. 222-232
2014
DOI: 10.1016/j.cirpj.2014.04.002
Abstract anzeigen
This paper presents the application of the substitution method for the estimation of measurement uncertainties using calibrated workpieces in X-ray computed tomography (CT) metrology. We have shown that this, well accepted method for uncertainty estimation using tactile coordinate measuring machines, can be applied to dimensional CT measurements. The method is based on repeated measurements carried out on a calibrated master piece. The master piece is a component of a dose engine from an insulin pen. Measurement uncertainties estimated from the repeated measurements of the master piece were transferred on to additionally scanned uncalibrated workpieces which provided the necessary link for achieving traceable measurements.
Maschinenbau und MechatronikZeitschriftenartikel
P. Müller, A. Cantatore, J. Andreasen, Jochen Hiller, L. Chiffre
Computed Tomography as a Tool for Tolerance Verification of Industrial Parts
Procedia CIRP, vol. 10, pp. 125-132
2013
DOI: 10.1016/j.procir.2013.08.022
Abstract anzeigen
Computed tomography (CT) is becoming an important technology for industrial applications, enabling fast and accurate control of manufactured parts. In only a few minutes, a complete 3D model of a part may be obtained, allowing measurements of external and internal features. This paper presents results of tolerance verification of a plastic housing for an insulin pen manufactured by Novo Nordisk A/S. Calculation of measurement uncertainties was taken into account in decision making regarding the specified tolerance limits. Variables in terms of CT systems, data sets, and evaluation software are considered in this study.
Maschinenbau und MechatronikZeitschriftenartikel
P. Müller, Jochen Hiller, A. Cantatore, L. Chiffre
A study on evaluation strategies in Dimensional X-ray computed tomography by estimation of measurement uncertainties
International Journal of Metrology and Quality Engineering, vol. 3, no. 2, pp. 107-115
2012
DOI: 10.1051/ijmqe/2012011
Abstract anzeigen
Computed tomography has entered the industrial world in 1980’s as a technique for non-destructive testing and has nowadays become a revolutionary tool for dimensional metrology, suitable for actual/nominal comparison and verification of geometrical and dimensional tolerances. This paper evaluates measurement results using different measuring strategies applied in different inspection software packages for volume and surface data analysis. The strategy influence is determined by calculating the measurement uncertainty. This investigation includes measurements of two industrial items, an aluminium pipe connector and a plastic toggle, a hearing aid component. These are measured using a commercial CT scanner. Traceability is transferred using tactile and optical coordinate measuring machines, which are used to produce reference measurements. Results show that measurements of diameter for both parts resulted in smaller systematic errors compared to distance and height measurements. It was found that uncertainties of all measurands evaluated on surface data were generally greater compared to measurements performed on volume data.
Angewandte Naturwissenschaften und WirtschaftsingenieurwesenBeitrag (Sammelband oder Tagungsband)
S. Weide, P. Gege, C. Schwarz, M. Bachmann, S. Holzwarth, M. Habermeyer, P. Müller, P. Haschberger, Paul Schötz, K. Lenhard, E. Bogner, T. Schwarzmaier
Flugzeuggetragene hyperspektrale Fernerkundung am Deutschen Zentrum für Luft- und Raumfahrt (DLR)
Vorträge Dreiländertagung - Wissenschaftlich-Technische Jahrestagung der DGPF, 01.-03.07.2010, Wien, Österreich, vol. 19
2010
TC FreyungBeitrag (Sammelband oder Tagungsband)
Peter Hofmann, P. Lohmann, S. Müller
Change Detection by Object-Based Change Indications
Proceedings of the 4th EARSeL Workshop on Remote Sensing for Developing Countries in Conjunction with GISDECO (June 4-7, 2008; Istanbul, Turkey]
2008
TC FreyungZeitschriftenartikel
Peter Hofmann, P. Lohmann, S. Müller
Concepts of an object-based change detection process chain for GIS update
International Archives of Photogrammetry and Remote Sensing, vol. 37, pp. 305-312
2008
NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenTAZ SpiegelauZeitschriftenartikel
H. Treichel, Günther Ruhl, P. Ansmann, R. Würl, C. Müller, M. Dietlmeier
Low dielectric constant materials for interlayer dielectric
(Invited Paper)
Microelectronic Engineering, vol. 40, no. 1, pp. 1-19
1998
DOI: 10.1016/S0167-9317(97)00185-8
Abstract anzeigen
The more advanced an integrated circuit becomes, the more stringent are the demands for certain properties of a dielectric or insulating material. In addition, it is essential that the layer maintain its specific electrical, physical and chemical properties after incorporation in the device structure and during subsequent processing. Due to temperature budget constraints and the accelerated decrease of feature sizes below 0.25 μm one can no longer rely on traditional choices but has to search for alternatives, both for low and high permittivity replacements. In the article we survey currently used low dielectric constant materials and future trends for micro-electronic applications.
Version: 2.1.1