Vth
International Science ConferenceCoordinate Measuring Technique
Vth
International Science ConferenceEugeniusz Ratajczyk , Warsaw University of Technology - chairman,
Albert Weckenmann, University Erlangen-Nuernberg - vice chairman,
Jan Szadkowski, Bielsko-Biala University - vice chairman,
Jan Malinowski, Bielsko-Biala University - secretary
Tomizo Kurosawa, National Institute of Advanced Industrial Science and Technology, Tsukuba
Thomas Mathia, Insitut Europeen de Tribologie C.N.R.S., Ecole Centrale de Lyon
Herbert P. Osanna, Technical University Wien
Hagen Reissner, Volkswagen AG, Saltzgitter
Walter E. Rumpf, Fachhochschule Frankfurt am Main
Yoshihisa Tanimura, National Institute of Advanced Industrial Science and Technology, Tsukuba
Franz Waeldele, National Bureau of Standard, Braunschweig
Lutz Wisweh, Otto von Guericke University, Magdeburg
Vit Zeleny, Czech Metrology Institute, Prague
Stanislaw Adamczak, Swietokrzyska Technical University, Kielce
Jan Barcentewicz, Institute of Metal Cutting IOS, Cracow
Sławomir Bialas, Warsaw University of Technology
Jan Chajda, Poznan Technical University
Jozef Gawlik, Cracow Technical University
Günter Grawel, Frenco GmbH, Aldorf
Holger Hage, OKM Optische Koordinatemesstechnik GmbH, Jena
Zbigniew Ramotowski, Central Office of Measures, Warsaw
Tadeusz Iglantowicz, Szczecin Technical University
Marek Nocun, Zeiss IMT, Warsaw
Kazimierz Oczos, Rzeszow Technical University
Zbigniew Ramotowski, Central Office of Measures, Warsaw
Jerzy Sladek, Cracow Technical University
Krzysztof Tubielewicz, Czestochowa Technical University
Henryk Zebrowski, Wroclaw Technical University.
Albert Weckenmann, Thomas Killmaier
WEPROM – Code for the automated process chain from the product development to the inspection
Summary: Shortening the planning times and reducing development and manufacturing costs are strategic specifications, to which the entire product developing process must subordinate itself. The consequent use of available metrological processes and components can ensure the long-term stability of production processes. A continuous process chain has a substantial potential by using the possibilities of the today’s CAD technology while avoiding the multiplicity of different documents and mutual faulty operations. With a worker-oriented integral effort, the process chain from the Cad system to an integrated inspection planning to the feature-flexible measuring on form tester and coordinate measuring machines can form a circle. Automatic production of a complete feature list directly from the CAD system and the uniform inspection planning under specification of feature-based measurement strategies creates the premise for standardized methodologies and international comparability of results of measurement.
Igor Piotr Kuritnyk, Petro Vankevicz
Optico-ambivalent Termometers
Summary:For measuring of bodies surfaces temperature worked up optico-ambivalent thermometer. Sensing element thermometer element done in appearance of two plates with diverse significance coefficient of linear thermal expansion. Mutual disposition and constructive execution of plates such, that attached to change of temperature obviously displays a distinctions of their temperature deformations. For thinking comfort and registration, having distinctions deformations on one of plates sensing element of element drifted reticulated grate. Visible part of reticulated grate proportional to difference of temperature plates deformations sensing element of element and deformation about measured temperature. Thinking provides amount count of retina lines and performs by the medium of distance optical system, which breaks down under radiant, photo-electric cell and impulses counter. Radiant and photo-electric cell optically related to help of two focusing devices. On radiant role can be adopted any laser emitter by power to 0,1 kW. In quality photo-electric cell in used a video camera with digital signal registration and specialized object-glass (microscope) which is sensible in light and infrared range spectrum an impulsed counter is a specially worked up device, which transforms been accorded ambivalent signal on strictly rectangular impulsed. Carrying counter capacity vacillates from 1 Hz to 65 kHz, error to 1 Hz attached to maximum frequency. All of data fixs “Computer”. Ambivalent thermometer sensible, simple, reliable, has sufficient exactness, modest in service and can take temperature of immovable and mobile bodies.
Katarzyna Czech-Dudek, Krzysztof Tubielewicz
Raster method of measurement of surface micro-geometry
Summary: This paper presents the non-contact raster method of measurement of surface roughness based on analysis of raster images. This method used in measurements in surface micro-geometry after high-speed turning.
Albert Weckenmann, Hagen Reißner, R. Roithmeier
AUKOM – New Training in Coordinate Metrology
Summary: Measurements on coordinate measuring machines (CMMs) must be executed considering objective comprehensive criteria, in order to ensure the comparability of the results of measurement. A profound and intensive training of the personnel responsible for the measurement is a necessary prerequisite for best practice measuring. The aim is to supply an established instrument-neutral training concept for coordinate metrology for the analysis, planning and execution of measurements and analyses of the data. This training concept is hierarchically structured in three levels. By this, the measurement uncertainty will be reduced and the comparability of measurement results will be increased.
Krzysztof Nozdrzykowski
The optimisation of control-shaft support and dimension conditions when measuring shape and location errors of the hole axis of the bearing seat
Summary: An analysis has been performed of measurement errors occurring in the method of estimating deviations of shape and location of the bearing-seat hole axis in the engine body using a control shaft and sensors. In a further part the problem of optimising the control shaft shape and the locations of its support in the holes of the bearing seats was discussed, which makes it possible to minimise measurement errors.
Anna Kapińska-Kiszko
Stability examination of sphere centre coordinate positions of the ball-plate after their displacement emerging from random mecanical stress.
Summary: The analysis of results of the ball-plate calibration obtained in the frame of comparison carried out by Central Office of Measures (Poland) and National Research Laboratory of Metrology (Japan) in 1999 is given in this paper. During this experiment the displacement of sphere centre coordinates are observed. The analysis of results of the ball-plate calibration carried out by University of Technology in Kraków in November 1999 and by PTB in April 2000 is given too. All results were referred to the calibration results obtained by PTB in 1997.
Adam Woźniak
Influence of the measuring object parameters on CMM touch trigger performance.
Summary: Touch trigger probes are widely used with CMM to indicate the position of their axes when contact between probe tip and the object surface. The performances of the measuring machine and the probe system are linked. There are many factors influencing probing accuracy. Some of them were examined and described in the earlier papers. In this paper we present the results of checking the influence of measured object form, surface texture and material Young’s modulus on pretravel variation and non-repeatability of the touch trigger probe.
Janusz Rzepka, Janusz Pieńkowski, Sławomir Sambor, Grzegorz Budzyń
Two mode laser interferometer as measurement system of CMM
Summary: Laser interferometer based on two mod He-Ne laser for application us measurement system of CMM is presented. The base resolution of the system, without interpolation board, is 80 nm. The wavelength of the laser is compensated according to the temperature, the pressure and the humidity of the air and the temperature of the object under test. The accuracy of the measurement of displacement is 1.5 um/m for steel detail and 3.2 um/m for made from aluminum. The measurements with CMM having such laser measurement system could be done in shop condition. That will save the time usually waste for equalize the temperature of the detail with temperature of the air in measuring laboratory. The measurements could be done at once after machining when the tested piece is still warm. That decrease the number of scraps, because the defects will be quickly detected and production process could be quickly adjusted. The two mod operation of the laser give the possibility to use two modes for two separate measurement axes. That will reduce the cost of the CMM.
Paweł Swornowski
The errors of the CMM software algorithms shown on the example of the length and angle measurement
Summary: There were 10 algorithms of CMM software tested on length and angle measurement between two planes with the shape deviation. The way of generation of the final error was analyzed step by step. The attention was paid to the software of CMM that cause a large error in the results, the methods to minimize those errors were presented.
Paweł Swornowski
The choice of the number of measuring points for the circle with the shape deviation.
Summary: The influence of the number of measuring points on the circle function with assumpted shape deviation had been tested using 9 programs of the CMM software of the leading Western companies. The circle function was based on 4, 8, 16 and 32 measuring points. The results were compared with a Gauss algorithm and then classified into classes I and II of different deviation level. The class I had a deviation below or equal to ±1µm, while the class II > ±1 µm. The test proved the urge need of increasing the minimal number of measuring points in order to reach the required accuracy.
Marek Migacz, Marcin Mączka
Reverse engineering in using to free forms surface machining.
Summary: Paper presents a method of realization of the transformation of the model into the product. Process is performed within few steps: digitalization using ECLIPSE measuring machine with HOLOS NT software. Correction of the model using CAD system, preparation of the machining program using CAM system, machining on MICRON CNC milling center and measurements of the obtained product to evaluate the accuracy of the transformation of the model into the final product.
Krzysztof Kudźma, Karol Załachowski
Measurements of geometric accuracy of machine-tools bedways systems by means of electronic level.
Summary: Paper shows possibilities of measurement of measurements of geometrical precision of machine tool guide system by means of electronic levels (LEVELTRONIC NT made by WYLER company) and using of measurement results for estimation of complex indices of tool movement. Presentation of idea of expanding measuring capability of levels by applying of elaborated equipment and software provided. Results achieved in the research are comparable to measurement results made on CMM ECLIPSE.
Marek Migacz, Krzysztof Kudźma
The Use of Eclipse CMM for evaluation of geometric errors of milling machine bedways systemy.
Summary: A measuring method of form errrors for the table and the sledge milling machine slideways is presented. The measurements are preceded by the construction of the CAD that is used to calculate deviation for measured points. For checking the slideways a CMM Eclipse CNC with CALYPSO and HOLOS-NT software, equipped in piezoelectrical ST3 probe head was used. Measurings were made multiple times for measuring uncertainty calculation, which is roughness, and form errors from the measured surfaces. Measured points coordinates after averaging were used for aproximation of the actual surface, which will be used for slideways elements (table, sledge, and wedge) simmulation.
Mirosław Grzelka
The accuracy of the gears’ measurement with the co-ordinate measuring machine
Summary: Producers of the co-ordinate measuring machines (CMM) deliver many additional measuring programs for the special purposes. There are programs for the measurement of the gears. It is of great importance to carry out the accurate metrological analysis of the measuring process and the final error of the gears’ measurement with the CMM. Because it appeared impossible to analyze existing algorithms, the author created his own version and carried out the precise metrological analysis of the accuracy of basic gears’ deviations measurement. The worked out algorithms, software and metrological analysis of the CMM’s gears measurement accuracy is a basis for the complex measurement of the gears. The complex measuring method includes modern measuring devices and single flank measurement simulation. The final results are cinematic and dynamic deviations of the gear, the complex parameters describing the whole gear.
Mirosław Grzelka, Łukasz Mądry
The analysis of the influence of the gear deviations on the error of their measurement.
Summary: In the article, the analysis of the main inaccuracy of the gear (base radius and profile) caused by machining process and their influence on the measuring result (its error). The measuring process carried out with a Coordinate Measuring Machine using the software containing the Author’s algorithm. This analysis does not take into consideration the CMM and its measuring head inaccuracy (though such analysis has been undertaken, too, it is not a subject of the current article).
Ryszard Filipowski, Ryszard Kossowski
Analysis of the sphere location and radius measured on CMM.
Summary: The methods of determining the theoretical sphere position and its radius are described in this paper. The investigated sphere is determined basing on the file containing sphere center co-ordinates, obtained during the sphere measurement with a probe on the Co-ordinate Measuring Machine. The measuring points of the real object are positioned in the neighborhood of the theoretical sphere. The position and the radius of the theoretical sphere can be determined by several methods described in this paper. The software elaborated using the Fortran 77 programming can be used as the supplementary CMM software or it can also be applied beyond the CMM environment, in case of the limited software support available to the user. The paper is also aimed at discussing some mathematical methods for determining minimum of the linear or un-linear function of four independent variables. These computational methods are protected by software companies and remain unpublished
Michał Wieczorowski, Marcin Bauza, Łukasz Mądry
CMM calibration according to the procedures used in USA.
Summary: The origin of the paper arose from cooperation between Poznan University of Technology and University of North Carolina Charlotte where we take part in construction of a CMM for American customer. For this it was necessary to look into American requirements that are somehow different than the ones used in Europe. In the paper calibration procedures for different types of machines according to American classification was presented. Various factors influencing machine performance and methods of their assessment were described. Tests executed on machines included the ones connected with environment, repeatability, linear displacement accuracy and behavior in 3D were discussed. Relevant measuring procedures were shown.
Michał Wieczorowski, Marcin Bauza, Andrzej Cellary
Application of Matlab for filtering purposes in surface roughness assessment.
Summary: Filtration in surface asperity measurements considered as separation of signal connected with roughness from waviness and form errors is one of the most important and complicated issue of surface analysis. It is also sometimes a reason of differences in parameter values between various devices. Furthermore in research applications it is often necessary to perform an existing set of data in a non-standard way, which means creating own filtration algorithms. In the paper application of Matlab for filtering of asperities was presented. Results for some typical filters used in engineered surfaces were shown and compared.
Eugeniusz Ratajczyk
The possibility of use of plate standards in estimation of length error measurements of CMMs’ according to requirements of PN EN-IS0 10360-2.
Summary: The results of experiments connected with the estimation of CMM length measurement errors by ring plate master and gauge blocks in the way approaching the requirements of ISO 10360-2 standard are presented. The results should give the basis in answering the question if it is possible to obey the ISO 10 360-2 standard requirements when the plate master instead of gauge blocks is used.
Andrzej Koć, Tadeusz Sałaciński, Radosław Morek
Equation of the equidistant surface from tooth flank of Oerlikon Spirac-N gears for 3D measuring.
Summary: The theory of bevel gear is still little known compared with the theory of cylindrical gear. Since this paper deals with the accurate set of equations, it may eliminate the approximate solutions and the “prove and error” methods while manufacturing and while measuring a bevel gear tooth flank. Oerlikon Spirac-N teeth have been taken into account in the paper. Formulas derived in [1] have also been used here.
Marcin Starczak, Marek Migacz, Norbert Wisła
Documentation of CMM measurement strategies.
Summary: The paper presents principles for building a CMM-measuring-strategy documentation system. The need of such documentation system was shown. The results of inter-laboratory research in the range of documentation of measuring strategy of a steering gear housing were discussed. The paper was prepared in the frame of research project no 8 T07D 047 21 supported by KBN (State Committee of Scientific Research).
Władysław Jakubiec, Marcin Starczak, Mirosław Adamek
Evaluation of the accuracy of CMM calibration by means of assembled bar-ball gauge.
Summary: Models for analyse of CMM calibration accuracy with the use of dismountable bar-ball gauge are presented in the paper. These models take into account the influence of gauge errors, coaxiality of sphere centres as well as a problem connected with relocation of gauges in different positions. To solve this task a simulating technique was engaged with the use of the virtual measuring machine. The paper was prepared in the frame of research project no 8 T07D 047 21 supported by KBN (State Committee of Scientific Research).
Józef Jezierski, Eugeniusz Stepnowski, Marian Olszaniecki, Piotr Sieczka
Inspection of the petrol engine blocks by means of CMM and CNC-controlled machine tools.
Summary: The paper presents the experiences obtained during the inspection of combustion engines blocks. The inspection was carried out as inspection operations on machining centres with CNC control systems and as final inspection on coordinate measuring machines. The fix and fasten errors influencing on accuracy of manufacturing and measurements were discussed. The short characteristic of machines: Mandeli and Apollo RS-150 was presented. This characteristic includes CNC control system and the measurements by measuring probes.
Maciej Brylski, Wojciech Płowucha
Evaluation of roughness measurements results repeatability of surfaces having stratified functional characteristic.
Summary: In the paper the theoretical basis of Rpq, Rvq and Rmq parameters estimation procedures for surfaces having stratified functional properties are presented using the language of probability theory and mathematical statistics. Using the software prepared by authors, written in Delphi, repeatability analyse of measurement results was conducted. Measurements were taken on evaluation lengths having been parallel distributed in distances 0,6 millimetres. Measurements were made by means of Perthometer Concept (Mahr) profilometer equipped with measuring table with CNC controlled cross movement allowing among the other for topography measurements.
Stanisław Adamczak, Włodzimierz Makieła, Sebastian Fajdek
Algorithm for evaluation of free-form profile on the basis of coordinate measurements by means of trigger probes.
Summary: The latest co-ordinate machines produced by Zeiss equipped with pulse heads are provided with the software CALYPSO. In standard equipment, the program enables automatic identification of such elements as straight lines, planes, circles and also solids of revolution including spheres, cylinders and cones. This paper presents an algorithm used for the determination of plane curves with any profile from measuring results obtained on a co-ordinate machine using the least squares method. The proposed methodology is verified for circular and elliptic profiles basing on measurements and calculations performed on a machine ECLIPSE.
Stanisław Adamczak, Adam Janusiewicz, Zbigniew Zybała
Experimental comparison of profiles measured by means of CMM.
Summary: Measurements taken with coordinate machines are characterised by relatively high accuracy. The paper presents the analysis of the accuracy of ECLIPSE 550 machine, manufactured by Zeiss company, equipped with a ST3 ATAC pulse head, used for roundness profiles measurements. For the sake of the analysis, bearing rings were measured. They had been divided into three groups depending on roundness deviation. Then, with SADCOM program for statistical testing and roundness profiles comparison, the usability of the coordinate machine for profile measurements was evaluated. The results obtained with the help of Talyrond 73 and 200 specialist equipment were regarded as reference.
Stanisław Adamczak, Dariusz Michalski, Krzysztof Stępień
Computer aided evaluation of the accuracy of form measurements performed on CMM.
Summary: The paper presents the SADCOM computer program for profile measurement accuracy evaluation. The program analyses by comparison the measurements performed by means of various measuring devices. The software allows, among others, statistical and harmonic analyses of profiles, calculation of correlation coefficients of the compared profiles, calculation of error of method, graphical representation of roundness profiles in a traditional form and as an amplitude and phase spectrum. The program can be used for the roundness profiles comparison performed on CMM and traditional reference and non – reference devices.
Andrzej Tyka
Appplication of picture digital analysis from ccd camera in an additional instrumentation cmd (coordinating measurement devices) for controlling the geometrical quality of the product.
Summary: Assumptions of the application and utilization of an additional optical system of instrumentation of the measurement head CMD Eclipse in the form of a CCD camera applied alternately with the measurement contact probe are given. Problems connected with the geometrical conditions of measurements, optical CCD system, illumination of the surface of the measured object as well evaluation of the measurement resolution and repeatability of measurements while using the computer – realized analysis of the picture taken from the CCD camera are presented. The obtained measurements results have been discussed in relation to the applied measurements instrumentation, the results being oriented towards the realization of the SPC system for controlling the geometrical quality of the product.
Vít Zelený
Calibration of coordinate measuring machines with respect to standards
Streszczenie: The number of coordinate machines keeps increasing not only in the Czech Republic but also worldwide. Coordinate measuring machines (CMMs) are universal measuring machines that replace a lot of single-purpose gauges. These machines need regular calibrating. The aim of this paper is to present not only calibration procedures according to ISO 10360-2 and VDI 2617 standards but also the way of embodiment of CMMs into the advanced “GPS“ (Geometrical Product Specification) concept. The objective of new calibration methods using completely new calibration bodies is not only to assess the total uncertainty of the measuring probe position but also identify all 21geometrical errors, which can be entered as correction factors in modern CMMs to improve machine precision. Another target of new calibration methods is to shorten the calibration time.
Małgorzata Kujawińska, R. Sitnik, M. Węgiel, W. Załuski
Optical 3D shape measurement systems and data conversion into CAD/CAM anvironments.
Summary: The paper concerns the new trends in measurement methods aiding reverse engineering process. The system based on digital fringe/Gray code projection method (in intensity and multicolor method) and enabling automatic measurement of absolute co-ordinates of full 3D objects is presented. The algorithms facilitating cloud of points merging and a cloud conversion into the format acceptable by CAD/CAM/CAE are described. Exemplary results of application of the system are shown.
T. Kurosawa, Y. Tanimura
Current activities of dimensional measurements in National Metrology Institute of Japan.
Summary: This paper describes current activities for industrial dimensional measure- ments in NMIJ(old name:NRLM). We calibrate ball-plate and step gauge useful for calibration of CMM, estimating its measurement uncertainties in accordance with ISO guideline“GUM”. We are developing a new laser tracking system as a coordinate standard for next generation. We participated in the CC key comparisons of step gauge (CCL K5) and the e-Measure project between Japan and USA in order to realize a system of calibration procedure for client by using internet means. As the other activities there are flatness measurement, nanometrologies of small step height, 1D grating, linewidth, surface roughness and so on.
Piotr Paszta
Coordinate measurement of torus profile.
Summary: A geometrical analysis of the torus profile has been developed on the example of pipe connections formed by method of the coextrusion of materials from a disk. An analytical solution is given to the relationship that define the value of the radius of torus of the elbow end as formed from a disk. The performed geometrical analysis have shown that the profile of ends preformed can be regulated by the value of the eccentricity of position of the axis of the hole in the disk prepared to be extruded.
Zbigniew Humienny
Standardisation in the coordinate measuring technique
Summary: Six parts of the recently published standard ISO 10360 GPS – Acceptance and reverification test for coordinate measuring machine are shown. The scope of the new work item at Technical Committee ISO/TC 213 that should be finalized as standard ISO 15530 GPS – Coordinate measuring machines (CMM) – Techniques for determining the uncertainty of measurement is also presented. Actions for implementation and advance in the development of the Polish version of PN-EN ISO 10360 are pointed. The other standards that are significant for coordinate measurements are also indicated.
Halina Nieciąg, Zbigniew Chuchro
The method of Chebychev best fitting approximation in metrological software.
Summary: The paper proposes the new method developed for minimax approximation that is applied in new geometric best-fit procedures. The approximation performs minimising of the maximum geometric deviation according to the L1 norm, basing on the sampled points. The method utilises the M.R.Osborne and G.A.Whatson algorithm for non-linear L1 approximation. The procedure built on the presented method involves a SVD - matrix decomposition technique for solution of overdeterminated equations system. The proposed method will be verified for a number of various geometric element types.
Maurizio Ercole
Machine Vision for Gauging of Sheet Metal parts on CMM
Summary: The Machine Vision applied to Dimensional Metrology does not represent, per se, an absolute innovation. Since more than a decade artificial vision techniques are successfully utilised for certain measuring applications. The Flexible, Absolute Dimensional Inspection of large and very large Automobile components by means of Machine Vision is, nevertheless, a real novelty. Machine Vision for Gauging of Sheet Metal parts is based on the latest Optoelectronic and CMM Technologies and represents the future in this Application area. This document analyses the state of the art in this emerging Technology.
N. M. Durakbasa, P. H. Osanna
The Role of Co-ordinate Metrology in the Hierarchical Structure of Metrology and the System for Measurement Instruments Confirmation
Summary: In modern industrial production it is necessary and important for the quality of products and processes to confirm and check periodically measuring and monitoring devices. The system of the metrology hierarchy and additionally the international standards in the field of quality management systems ISO 9000: 2000 family require to establish a comprehensive control and confirmation system for the used measuring devices. Measuring and monitoring devices shall be used and tested to ensure that measurement capability is consistent with the measurement requirements. Co-ordinate metrology is of ever increasing importance in modern production engineering. For the user of co-ordinate measuring machine (CMM) the confidence in the accuracy of the CMM is the basis for practical measuring tasks. Besides parallel gauges, step gauges, gauge rings and calibrated discs, universal artefacts may be used for the periodic inspection, the detection and correction of inaccuracies of CMMs. The basic for the tests of co-ordinate measuring machines is given by the international standards for Geometrical Product Specification and Verification (GPS).
Barbara Juras
The calculation of primary surface in coordinate measurements of free-form surfaces based on spherical elements
Summary: The paper presents the problems of radius correction of free-form surfaces. To calculate the normal direction the spherical elements were used. The accuracy of this method was estimated by computer simulation technique.
Jerzy Sładek
The neural model of CMM – the model of trigger probe.
Summary: In this article presented are results of the research on developing a CMM model, based on application of artificial neural networks. The study main focus was modelling of the contact head’s errors. Described here is the new version of software for a virtual neural CMM. Also presented is the outcome of comparative research, performed for so developed model and actual measurement. This research special concern was to select such metrologic strategy and positioning of the standard that served as the measurement basis, as to enable the analysis of the head’s errors impact on the realised measurement’s accuracy. In conclusion presented are: assessment of the developed model and indicated directions for the further research.
Marek Kowalski, Robert Rakoczy
The influence of environmental temperature on errors field identified by means of gauge plates.
Summary: The paper presents the problem of influence of stabilised ambient temperature on position error vectors (on a plane) of coordinate measuring machines. The tests were performed using a hole plate made of Robax due to its considerable thermal stability. As a result error diagrams were achieved for a tested plane at different temperatures. Observed changes in an error field confirm significant influence of a temperature despite relatively long time of thermal stabilisation. Presented method of identification of thermal error field can be useful for developing thermal model of coordinate measuring machines.
Jan Chajda, Thomas G. Mathia, Michał Wieczorowski
Functional parameters of surface's morphology - myth, illusion or reality?
Thomas Rietze
Mobile 3D metrology - from tooling to assembly.
