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Suche nach „[Jochen] [Hiller]“ hat 68 Publikationen gefunden
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    DigitalFraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Vortrag

    Mario Salzinger, Peter Hornberger, Jochen Hiller

    Analysis and comparison of the surface filtering characteristics of computed tomography and tactile measurements

    6th Conference on Industrial Computed Tomography (iCT 2016), Wels, Österreich

    2016

    DigitalFraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Zeitschriftenartikel

    A. Detterbeck, M. Hofmeister, D. Haddad, D. Weber, M. Schmid, A. Hölzing, S. Zabler, E. Hofmann, K.-H. Hiller, P. Jakob, J. Engel, Jochen Hiller, U. Hirschenfelder

    Determination of the mesio-distal tooth width via 3D imaging techniques with and without ionizing radiation: CBCT, MSCT, and μCT versus MRI

    European Journal of Orthodontics, vol. 39, no. 3, pp. 310-319

    2016

    DOI: 10.1093/ejo/cjw047

    Abstract anzeigen

    Objective: The purpose of this study was to estimate the feasibility and accuracy of mesio-distal width measurements with magnetic resonance imaging (MRI) in comparison to conventional 3D imaging techniques [multi-slice CT (MSCT), cone-beam CT (CBCT), and µCT]. The measured values of the tooth widths were compared to each other to estimate the amount of radiation necessary to enable orthodontic diagnostics. Material and Methods: Two pig skulls were measured with MSCT, CBCT, µCT, and MRI. Three different judges were asked to determine the mesio-distal tooth width of 14 teeth in 2D tomographic images and in 3D segmented images via a virtual ruler in every imaging dataset. Results: Approximately 19% (27/140) of all test points in 2D tomographic slice images and 12% (17/140) of the test points in 3D segmented images showed a significant difference (P ≤ 0.05). The largest significant difference was 1.6mm (P < 0.001). There were fewer significant differences in the measurement of the tooth germs than in erupted teeth. Conclusions: Measurement of tooth width by MRI seems to be clinically equivalent to the conventional techniques (CBCT and MSCT). Tooth germs are better illustrated than erupted teeth on MRI. Three-dimensional segmented images offer only a slight advantage over 2D tomographic slice images. MRI, which avoids radiation, is particularly appealing in adolescents if these data can be corroborated in further studies.

    DigitalFraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Beitrag (Sammelband oder Tagungsband)

    Jochen Hiller, Peter Hornberger, Mario Salzinger

    Bewertung technischer Oberflächen mit Röntgen-Computertomographie

    Leitfaden zur Inspektion und Charakterisierung von Oberflächen mit Bildverarbeitung, Stuttgart, vol. 16

    2016

    ISBN: 978-3-8396-1097-8

    DigitalFraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Zeitschriftenartikel

    Jochen Hiller, Peter Hornberger

    Measurement accuracy in X-ray computed tomography metrology: Toward a systematic analysis of interference effects in tomographic imaging

    Precision Engineering, vol. 45, no. July, pp. 18-32

    2016

    DOI: 10.1016/j.precisioneng.2015.12.003

    Abstract anzeigen

    In this paper an investigation of interference effects leading to limitations of metrological performance of X-ray computed tomography (CT) used as a coordinate measuring technique is presented. Using reconstruction data, image quality metrics, and calculations of artifact formation, a deeper understanding and explanation of the physical and technical limitations of CT used in dimensional metrology is given. This is demonstrated in a case study using a simple hollow cylinder made of steel as a test object and calibration measurements from a tactile coordinate measuring machine (CMM). Two different threshold determination strategies for surface computation are applied. Within the study it is also shown that CT image properties, threshold determination strategies, and systematic and random measurement errors must have a definite correlation. As a conclusion it is recommended to focus more strongly on the correlation of local CT image quality and data evaluation operations in order to reduce systematic errors in surface computation and to increase repeatability of dimensional CT measurements.

    DigitalFraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Zeitschriftenartikel

    A. Gameros, L. Chiffre, H. Siller, Jochen Hiller, G. Genta

    A reverse engineering methodology for nickel alloy turbine blades with internal features

    CIRP Journal of Manufacturing Science and Technology, vol. 9, no. May, pp. 116-124

    2015

    DOI: 10.1016/j.cirpj.2014.12.001

    Abstract anzeigen

    The scope of this work is to present a reverse engineering (RE) methodology for freeform surfaces, based on a case study of a turbine blade made of Inconel, including the reconstruction of its internal cooling system. The methodology uses an optical scanner and X-ray computed tomography (CT) equipment. Traceability of the measurements was obtained through the use of a Modular Freeform Gage (MFG). An uncertainty budget is presented for both measuring technologies and results show that the RE methodology presented is promising when comparing uncertainty values against common industrial tolerances.

    DigitalFraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Zeitschriftenartikel

    Peter Landstorfer, Jochen Hiller

    Präzision in drei Freiheitsgraden - Exakte Bauteilpositionierung bei CT-Messungen ohne zusätzliche Antriebe

    inspect, no. 2

    2015

    Abstract anzeigen

    Die präzise und reproduzierbare Ausrichtung von Messobjekten im CT ist eine wesentliche Voraussetzung für die Erzeugung vollständiger und genauer Datensätze. Mit einer universellen Positioniereinheit für industrielle Computertomographen (CT), die vollständig von den im Gerät vorhandenen Achsen angetrieben wird und dabei eine Ausrichtung von Messobjekten in drei Freiheitsgraden ermöglicht, wird dies in Zukunft einfacher zu realisieren sein.

    DigitalFraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Beitrag (Sammelband oder Tagungsband)

    Simon Rettenberger, Peter Hornberger, A. Tissen, Jochen Hiller, S. Zabler

    Messtechnik und Materialprüfung an belasteten Bauteilen mit In-situ-Computertomographie

    Leitfaden zur industriellen Röntgentechnik, vol. 15

    2015

    ISBN: 978-3-8396-0913-2

    DigitalFraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Beitrag (Sammelband oder Tagungsband)

    Peter Hornberger, Christian Aichinger, Jochen Hiller

    Dimensionelles Messen mit Computertomographie

    Leitfaden zur industriellen Röntgentechnik, vol. 15

    2015

    ISBN: 978-3-8396-0913-2

    DigitalFraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Beitrag (Sammelband oder Tagungsband)

    Peter Landstorfer, Thomas Miller, Jochen Hiller

    Automatisierung von Mess- und Prüfprozessen mit Computertomographie

    Leitfaden zur industriellen Röntgentechnik, vol. 15

    2015

    ISBN: 978-3-8396-0913-2

    DigitalFraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Zeitschriftenartikel

    S. Horlemann, E. Kraus, B. Baudrit, M. Bastian, A. Tissen, Jochen Hiller, S. Zabler

    In-situ-Prüfungen von Kunststoff-Klebeverbindungen mit Computertomographie

    KGK Rubber Point - Kautschuk Gummi Kunststoffe, no. 4

    2015

    Abstract anzeigen

    Das mechanische Verhalten von geklebten PEEK-Verbindungen wurde unter Belastung mittels Computertomographie in-situ untersucht. Hierbei wurden für eine Zugscher-Probe die Dehnungsverteilungen in der gesamten Klebeverbindung sowie in der Klebeebene lokal bei einem mehraxialen Zustand analysiert.

    DigitalFraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Zeitschriftenartikel

    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.

    DigitalFraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Beitrag (Sammelband oder Tagungsband)

    D. Schmid, J. Merz, Jochen Hiller

    New Method for Master Pattern Tool Correction Based on Computed Tomography Data and Intelligent Reverse Engineering

    iCT 2014 5th Conference on Industrial Computed Tomography (iCT) 2014

    2014

    Fraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Vortrag

    D. Schmid, J. Merz, Jochen Hiller

    New Method for Master Pattern Tool Correction Based on Computed Tomography Data and Intelligent Reverse Engineering

    iCT Conference 2014 (Conference on Industrial Computed Tomography), Wels, Österreich

    2014

    Fraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Zeitschriftenartikel

    A. Tissen, Peter Hornberger, Jochen Hiller, S. Zabler, B. Baudrit, S. Horlemann

    Dimensionelles Messen und Materialprüfung an belasteten Bauteilen mit In-situ-CT

    inspect, vol. 15, no. 4, pp. 54-56

    2014

    Abstract anzeigen

    Die Anwendung der Röntgen-Computertomographie (CT) als zerstörungsfreie Prüfung (zfP) entwickelt sich zunehmend zu einem unverzichtbaren bildgebenden Verfahren in der Qualitätssicherung. Seit dem letzten Jahrzehnt wird diese Technologie verstärkt auch in der dimensionellen Messtechnik eingesetzt.

    Fraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Zeitschriftenartikel

    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.

    Fraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Zeitschriftenartikel

    Jochen Hiller, G. Genta, G. Barbato, L. Chiffre, R. Levi

    Measurement Uncertainty Evaluation in Dimensional X-ray Computed Tomography Using the Bootstrap Method

    International Journal of Precision Engineering and Manufacturing, vol. 15, no. 4, pp. 617-622

    2014

    DOI: 10.1007/s12541-014-0379-9

    Abstract anzeigen

    Industrial applications of computed tomography (CT) for dimensional metrology on various components are fast increasing, owing to a number of favorable properties such as capability of non-destructive internal measurements. Uncertainty evaluation is however more complex than in conventional measurement processes, e.g., with tactile systems, also due to factors related to systematic errors, mainly caused by specific CT image characteristics. In this paper we propose a simulation-based framework for measurement uncertainty evaluation in dimensional CT using the bootstrap method. In a case study the problem concerning measurement uncertainties was addressed with bootstrap and successfully applied to ball-bar CT measurements. Results obtained enabled extension to more complex shapes such as actual industrial components as we show by tests on a hollow cylinder workpiece.

    Fraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Zeitschriftenartikel

    K. Poulios, G. Svendsen, Jochen Hiller, P. Klit

    Coefficient of Friction Measurements for Thermophastics and Fibre Composites Under Low Sliding Velocity and High Pressure

    Tribology Letters, vol. 51, no. 2, pp. 191-198

    2013

    DOI: 10.1007/s11249-013-0107-0

    Abstract anzeigen

    Friction materials for typical brake applications are normally designed considering thermal stability as the major performance criterion. There are, however, brake applications with very limited sliding velocities, where the generated heat is insignificant. In such cases it is possible that friction materials which are untypical for brake applications, like thermoplastics and fibre composites, can offer superior performance in terms of braking torque, wear resistance and cost than typical brake linings. In this paper coefficient of friction measurements for various thermoplastic and fibre composite materials running against a steel surface are presented. All tests were carried out on a pin-on-disc test-rig in reciprocating operation at a fixed sliding speed and various pressure levels for both dry and grease lubricated conditions. Moreover, a generic theoretical framework is introduced in order to interpret the changes of friction observed during the running-in phase.

    Fraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Zeitschriftenartikel

    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.

    DigitalFraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Zeitschriftenartikel

    Jochen Hiller, L. Reindl

    A computer simulation platform for the estimation of measurement uncertainties in dimensional X-ray computed tomography

    Measurement, vol. 45, no. 8, pp. 2166-2182

    2012

    DOI: 10.1016/j.measurement.2012.05.030

    Fraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Vortrag

    Jochen Hiller

    Systematic Errors in Dimensional X-ray Computed Tomography

    Maletekniske Dage, Taastrup, Dänemark

    2012