M&MS - volume XVIII - number 3/2011

POLISH ACADEMY OF SCIENCES

Division IV: Engineering Sciences

Committee on Metrology
and Scientific Instrumentation

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VOLUME XVIII - NUMBER 3/2011

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CONTENTS

1. R. Zielonko - Editorial note	347
2. Tadeusiewicz M., Hałgas S. - Multiple soft fault diagnosis of nonlinear dc circuits considering component tolerances	349
3. Pankanin G. - What is the role of the stagnation region in Karman vortex shedding?	361
4. Zygarlicki J., Mroczka J. - Short time algorithm of power waveforms fundamental harmonic estimation with use of prony's methods	371
5. Borkowski J. - Continuous and discontinuous linear approximation of the window spectrum by least squares method	379
6. Borkowski J. - Minimization of maximum errors in universal approximation of the unit circle by a polygon	391
7. Murugarajan A., Samuel G.L. - Measurement, modeling and evaluation of surface parameter using capacitive-sensor-based measurement system	403
8. Zawada-Tomkiewicz A., Ściegienka R. - Monitoring of a micro-smoothing process with the use of machined surface images	419
9. Wojciechowski S. - Machined surface roughness including cutter displacements in milling of hardened steel	429
10. Swornowski P. - A new diagnosing method of the internal structure of the titanium fan of a jet engine with laser ultrasonics	441
11. Artyukh Y., Boole E. - Jitter measurement on the basis of high-precision event timer	453
12. Tomczyk K. - Procedure for correction of the ECG signal error introduced by skin-electrode interface	461
13. Piskorowski J., Kaszyński R. - Analytical synthesis of parameter-varying filter of constant component with application to switching systems	471
14. Muravyov S.V., Zlygosteva G.V., Borikov V.N. - Multiplicative method for reduction of bias in indirect digital measurement result	481
15. Czop P. - Application of an inverse data-driven model for reconstructing wheel movement signals	491

ABSTRACTS & FULL PAPERS

347

contents

EDITORIAL NOTE

Dear Readers,

It is my great pleasure to inform you that our journal Metrology and Measurement Systems (M&MS) is indexed with the Impact Factor of 0.587 in the recent edition of Journal Citation Report (JCR). This value is positioning it in the middle of the ranking list of journals in the subject category Instruments and Instrumentation.

The appearance of M&MS in the scientific base JCR is the next significant step in a development of the journal, after year 2008, when it was introduced on the Thomson-Reuters Master Journal List. This is an objective indication of the growing international position of the journal.

I would like to take advantage of this opportunity to highlight some of our accomplishments in the last three years, as well as initiatives we are going to undertake in response to new challenges concerning international competition among journals.

If significant accomplishments are concerned, I would like to mention:
- the enhancement of the graphical form of the journal with a newly designed cover which makes it better recognizable among scientific journals published in the field of measurement science and technology, as well as among other journals published under auspices of Polish Academy of Sciences; - the introduction of the journal on the MetaPress platform of electronic publishing (www.versita.com/mms);
- the implementation of the Internet Editorial System (IES) for manuscript submission and processing (www.bravo.iem.pw.edu.pl/mams2);
- the enhancement of the journal website (www.metrology.pg.gda.pl), i.a. by more precise formulation of the Instruction for Authors and development of many other facilities simplifying manuscript preparation and submission.

Responding to the new challenges, we are going to continue our efforts aimed at increasing the scientific quality of papers published in M&MS and improving the reviewing procedures; at increasing international diversity of authors, reviewers and associated editors; as well as at making further improvements in IES.

The general mission of the journal is remaining unchanged. It consists in enhancing the world-wide exchange of information on the advancements in the field of measurement science and technology, with particular focus on the areas where the activity of the other metrologyrelated journals is insufficient. The main priority is given to supporting young researchers in their scientific development by publishing selected research results recorded in their Ph.D. and D.Sc. theses.

In conclusion, I would like to thank all Authors and Reviewers, as well as Members of International Programme Committee and Editorial Board for productive cooperation. I would like to thank also the Chairman and other Members of the Committee on Metrology and Scientific Instrumentation of Polish Academy of Sciences for their constant support of the journal. My special thanks go to Professor Roman Z. Morawski, Chairman of International Programme Committee, for his creative cooperation in all undertakings aimed at the development of the journal; as well as to Professor Remigiusz Rak and Mr. Marcin Godziemba-Maliszewski for elaboration and implementation of IES.

Romuald Zielonko
Editor-in-Chief

349

contents

MULTIPLE SOFT FAULT DIAGNOSIS OF NONLINEAR DC CIRCUITS CONSIDERING COMPONENT TOLERANCES

Michał Tadeusiewicz, Stanisław Hałgas

Technical University of Łódź, ul. Stefanowskiego 18/22, 90-924 Łódź, Poland (michal.tadeusiewicz@p.lodz.pl)

Abstract
This paper is devoted to multiple soft fault diagnosis of analog nonlinear circuits. A two-stage algorithm is offered enabling us to locate the faulty circuit components and evaluate their values, considering the component tolerances. At first a preliminary diagnostic procedure is performed, under the assumption that the non-faulty components have nominal values, leading to approximate and tentative results. Then, they are corrected, taking into account the fact that the non-faulty components can assume arbitrary values within their tolerance ranges. This stage of the algorithm is carried out using the linear programming method. As a result some ranges are obtained including possible values of the faulty components. The proposed approach is illustrated with two numerical examples.

Keywords: analog circuits, fault diagnosis, multiple faults, nonlinear circuits

Full paper (PDF, 773kB)

361

contents

WHAT IS THE ROLE OF THE STAGNATION REGION IN KARMAN VORTEX SHEDDING?

Grzegorz L. Pankanin

Institute of Electronic Systems, Warsaw University of Technology, ul. Nowowiejska 15/19, 00-665 Warsaw, Poland (g.pankanin@ise.pw.edu.pl)

Abstract
This paper is devoted to the problem of the appearance of a stagnation region during Karman vortex shedding. This particular phenomenon has been addressed by G. Birkhoff in his model of vortices generation. Experimental results obtained by various research methods confirm the existence of a stagnation region. The properties of this stagnation region have been described based on experimental findings involving flow visualisation and hot-wire anemometry. Special attention has been paid to the relationship between the existence of a slit in the bluff body and the size of the stagnation region. The slit takes over the role of the stagnation region as an information channel for generating vortices.

Keywords: flow measurement, Karman vortex shedding, bluff body, stagnation region

Full paper (PDF, 1457kB)

371

contents

SHORT TIME ALGORITHM OF POWER WAVEFORMS FUNDAMENTAL HARMONIC ESTIMATION WITH USE OF PRONY'S METHODS

Jarosław Zygarlicki¹⁾, Janusz Mroczka²⁾

1) Opole University of Technology, Institute of Power Engineering, Prószkowska 76, 45-758 Opole, Poland (j.zygarlicki@po.opole.pl, +48 77 40 00 547)
2) Wroclaw University of Technology, Chair of Electronic and Photonic Metrology, Bolesława Prusa 53/55, 50-317 Wrocław, Poland (janusz.mroczka@pwr.wroc.pl, +48 71 320 62 32)

Abstract
This paper presents an example of practical use of Prony's method for monitoring of power waveform fundamental harmonic fluctuations, which is required for the analysis of window synchronizations in frequency analyses in power monitoring systems. The example presented offers verification of the authors' theoretical considerations published earlier in articles about Prony's method and its opportunities for practical use for real life signals. The investigations shown are based on the least squares Prony's method, which, in connection with digital filtrations, enables estimations of fundamental frequency at the rate of even tens of times per one fundamental harmonic period.

Keywords: Power quality, Prony's method, harmonics, measurements

Full paper (PDF, 782kB)

379

contents

CONTINUOUS AND DISCONTINUOUS LINEAR APPROXIMATION OF THE WINDOW SPECTRUM BY LEAST SQUARES METHOD

Józef Borkowski

Wroclaw University of Technology, Chair of Electronic and Photonic Metrology, ul. B. Prusa 53/55, 50-317 Wroclaw, Poland (Jozef.Borkowski@pwr.wroc.pl)

Abstract
This paper presents the general solution of the least-squares approximation of the frequency characteristic of the data window by linear functions combined with zero padding technique. The approximation characteristic can be discontinuous or continuous, what depends on the value of one approximation parameter. The approximation solution has an analytical form and therefore the results have universal character. The paper presents derived formulas, analysis of approximation accuracy, the exemplary characteristics and conclusions, which confirm high accuracy of the approximation. The presented solution is applicable to estimating methods, like the LIDFT method, visualizations, etc.

Keywords: data window, spectrum approximation, interpolated DFT, LIDFT, spectrum estimation, zero padding

Full paper (PDF, 888kB)

391

contents

MINIMIZATION OF MAXIMUM ERRORS IN UNIVERSAL APPROXIMATION OF THE UNIT CIRCLE BY A POLYGON

Józef Borkowski

Wroclaw University of Technology, Chair of Electronic and Photonic Metrology, ul. B. Prusa 53/55, 50-317 Wroclaw, Poland (Jozef.Borkowski@pwr.wroc.pl)

Abstract
This paper presents a universal approximation of the unit circle by a polygon that can be used in signal processing algorithms. Optimal choice of the values of three parameters of this approximation allows one to obtain a high accuracy of approximation. The approximation described in the paper has a universal character and can be used in many signal processing algorithms, such as DFT, that use the mathematical form of the unit circle. One of the applications of the described approximation is the DFT linear interpolation method (LIDFT). Applying the results of the presented paper to improve the LIDFT method allows one to significantly decrease the errors in estimating the amplitudes and frequencies of multifrequency signal components. The paper presents the derived formulas, an analysis of the approximation accuracy and the region of best values for the approximation parameters.

Keywords: Unit circle, approximation by polygon, LIDFT, interpolated DFT, zero padding

Full paper (PDF, 779kB)

403

contents

MEASUREMENT, MODELING AND EVALUATION OF SURFACE PARAMETER USING CAPACITIVE-SENSOR-BASED MEASUREMENT SYSTEM

Murugarajan A., Samuel G.L.

Manufacturing Engineering Section, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai-600 036, India (murugarajan01@hotmail.com; samuelgl@iitm.ac.in, +91 44 22 57 4699)

Abstract
Surface roughness parameter prediction and evaluation are important factors in determining the satisfactory performance of machined surfaces in many fields. The recent trend towards the measurement and evaluation of surface roughness has led to renewed interest in the use of newly developed non-contact sensors. In the present work, an attempt has been made to measure the surface roughness parameter of different machined surfaces using a high sensitivity capacitive sensor. A capacitive response model is proposed to predict theoretical average capacitive surface roughness and compare it with the capacitive sensor measurement results. The measurements were carried out for 18 specimens using the proposed capacitive-sensor-based non-contact measurement setup. The results show that surface roughness values measured using a sensor well agree with the model output. For ground and milled surfaces, the correlation coefficients obtained are high, while for the surfaces generated by shaping, the correlation coefficient is low. It is observed that the sensor can effectively assess the fine and moderate rough-machined surfaces compared to rough surfaces generated by a shaping process. Furthermore, a linear regression model is proposed to predict the surface roughness from the measured average capacitive roughness. It can be further used in on-machine measurement, on-line monitoring and control of surface roughness in the machine tool environment.

Keywords: capacitive sensor, surface roughness, machined surfaces

Full paper (PDF, 2986kB)

419

contents

MONITORING OF A MICRO-SMOOTHING PROCESS WITH THE USE OF MACHINED SURFACE IMAGES

Anna Zawada-Tomkiewicz, Ryszard Ściegienka

Department of Mechanical Engineering, Koszalin University of Technology, ul. Raclawicka 15-17, 75-620 Koszalin, Poland (anna.zawada-tomkiewicz@tu.koszalin.pl; ryszard.sciegienka@tu.koszalin.pl)

Abstract
Industrial applications require functional surfaces with a strictly defined micro-texture. Therefore engineered surfaces need to undergo a wide range of finishing processes. One of them is the belt grinding process, which changes the surface topography on a range of roughness and micro-roughness scales. The article describes the use of machined surface images in the monitoring process of micro-smoothing. Machined surface images were applied in the estimation of machined surface quality. The images were decomposed using two-dimensional Discrete Wavelet Transform. The approximation component was analyzed and described by the features representing the geometric parameters of image objects. Determined values of image features were used to create the model of the process and estimation of appropriate time of micro-smoothing.

Keywords: Belt grinding process, Surface roughness & micro-roughness, Surface image, Wavelet decomposition

Full paper (PDF, 2640kB)

429

contents

MACHINED SURFACE ROUGHNESS INCLUDING CUTTER DISPLACEMENTS IN MILLING OF HARDENED STEEL

Szymon Wojciechowski

Poznan University of Technology, Faculty of Mechanical Engineering, ul. Piotrowo 3, 60-965 Poznan, Poland (sjwojciechowski@o2.pl)

Abstract
The work presented here, concentrates on experimental surface roughness analysis in the milling of hardened steel using a monolithic torus mill. Machined surface roughness with respect to milling process dynamics has been investigated. The surface roughness model including cutter displacements has been developed. Cutting forces and cutter displacements (vibrations) were measured in order to estimate their quantitative influence on Ra and Rz parameters. The cutter displacements were measured online using a scanning 3D laser vibrometer. The influence of cutting speed ν_c on surface roughness parameters (Ra, Rz) was also studied. The research revealed that real surface roughness parameters are significantly higher than those calculated on the basis of a kinematic-geometric basic model, and their values are strongly dependent on dynamic cutter displacements.

Keywords: milling, surface roughness, dynamics, hardened steel, scanning vibrometry

Full paper (PDF, 1607kB)

441

contents

A NEW DIAGNOSING METHOD OF THE INTERNAL STRUCTURE OF THE TITANIUM FAN OF A JET ENGINE WITH LASER ULTRASONICS

Paweł J. Swornowski

Poznan University of Technology, Faculty of Mechanical Engineering, Institute of Mechanical Technology, pl. M. Sklodowskiej-Curie 5, 60-965 Poznan, Poland (swornowski@wp.pl, +48 61 665 3595)

Abstract
Advanced metallic material processes (titanium) are used or developed for the production of heavily loaded flying components (in fan blade construction). The article presents one process for diagnosing the blade interior by means of laser ultrasonography. The inspection of these parts, which are mainly made of titanium, requires the determination of the percentage of bonded grain sizes from around 10 to 30 µm. This is primarily due to the advantages of a high signal-to-noise ratio and good detection sensitivity. The results of the research into the internal blade structure are attached.

Keywords: Non Destructive Testing (NDT), laser ultrasonic, titanium fan, aerospace

Full paper (PDF, 984kB)

453

contents

JITTER MEASUREMENT ON THE BASIS OF HIGH-PRECISION EVENT TIMER

Yuri Artyukh, Eugeny Boole

Institut of Electronics and Computer Science, 14 Dzerbenes Str., LV-1006 Riga, Latvia (artyukh@edi.lv)

Abstract
Currently the high-precision event timers represent powerful tools for time measurement in various applications, including jitter measurement. Applied potential of this technology is illustrated by the example of clock jitter measurement and analysis based on the application of a high-precision event timer. The basic measurement procedures resulting in estimations of commonly used jitter parameters (such as accumulated jitter, period jitter, clock-to-clock jitter) are discussed. An approach to informal interpretation of statistical jitter characteristics based on theoretical jitter model and results of computer simulation is offered. Experimental results of jitter measurement and analysis for high-precision clock oscillators confirm the assumption that currently the event timing can provide for jitter measurement precision comparable with traditional oscilloscope-based techniques.

Keywords: jitter measurement, event timer, accumulated jitter, statistical jitter analysis

Full paper (PDF, 696kB)

461

contents

PROCEDURE FOR CORRECTION OF THE ECG SIGNAL ERROR INTRODUCED BY SKIN-ELECTRODE INTERFACE

Krzysztof Tomczyk

Cracow University of Technology, Faculty of Electrical and Computer Engineering, ul. Warszawska 24, 31-155 Cracow, Poland, (petomczy@cyf-kr.edu.pl)

Abstract
The paper presents a procedure for correction of the error of an ECG signal, introduced by the skin-electrode interface. This procedure involves three main measuring-calculating stages: parametrical identification of the mathematical model of the interface, realized directly before the diagnostic measurements, registration of the signal at the output of electrodes as well as reconstruction of the input signal of the interface.
The first two stages are realized in the on-line mode, whereas the operation of signal reconstruction presents a numerical task of digital signal processing and is realized in the off-line mode through deconvolution of the registered signal with the transfer function of the skin-electrode interface.
The aim of the paper is to discuss in detail the procedure of parametric identification of the skin-electrode interface with the use of a computer system equipped with a DAQ card and LabVIEW software. The algorithm for error correction introduced by this interface is also presented.

Keywords: Identification of skin-electrode interface, signals reconstruction

Full paper (PDF, 1656kB)

471

contents

ANALYTICAL SYNTHESIS OF PARAMETER-VARYING FILTER OF CONSTANT COMPONENT WITH APPLICATION TO SWITCHING SYSTEMS

Jacek Piskorowski, Roman Kaszyński

West Pomeranian University of Technology, Department of Electrical Engineering, Gen. Sikorskiego 37, 70-313 Szczecin, Poland (jacek.piskorowski@zut.edu.pl, +48 91 449 5235, roman.kaszynski@zut.edu.pl)

Abstract
In this paper, we propose a concept of a continuous-time filter of constant component that exhibits a very short response in the time domain if compared to the traditional time-invariant filter. The improvement of the filter dynamics was achieved as a result of the time-varying parameters which were introduced to the filter structure. Such a designed filter is then applied in a system which switches many distorted signals which should be filtered as fast as possible. The paper is of review nature and presents both a theoretical background of the proposed filter and the results of simulations.

Keywords: data acquisition, analog signal processing, transient behavior, dynamics, switching systems, linear parameter-varying technique (LPV), linear time-varying systems (LTV).

Full paper (PDF, 810kB)

481

contents

MULTIPLICATIVE METHOD FOR REDUCTION OF BIAS IN INDIRECT DIGITAL MEASUREMENT RESULT

Sergey V. Muravyov, Galina V. Zlygosteva, Valeriy N. Borikov

National Research Tomsk Polytechnic University, Institute of Cybernetics, Department of Computer-aided Measurement Systems and Metrology, Pr. Lenina, 30, 634050 Tomsk, Russia (muravyov@camsam.tpu.ru, +7 3822 417527)

Abstract
The error reduction technique, based on inverse transformation, for a shunt active resistance measurement using an ammeter and voltmeter is considered. When computing a corrected reading only multiplicative operations on two measurement results are used, namely squaring and division. The proposed method allows to increase resistance measurement accuracy by about two orders of magnitude what has been validated by both theoretical and experimental outcomes.

Keywords: bias, error reduction technique, shunt ohmic resistance, indirect measurement

Full paper (PDF, 899kB)

491

contents

APPLICATION OF AN INVERSE DATA-DRIVEN MODEL FOR RECONSTRUCTING WHEEL MOVEMENT SIGNALS

Piotr Czop

AGH University of Science and Technology, Department of Robotics and Mechatronics, Al. Mickiewicza 30, 30-059 Kraków, Poland (piotr.czop@labmod.com, +48 502 026 501)

Abstract
This paper considers a method for indirect measuring the vertical displacement of wheels resulting from the road profile, using an inverse parametric data-driven model. Wheel movement is required in variable damping suspension systems, which use an onboard electronic control system that improves ride quality and vehicle handling in typical maneuvres. This paper presents a feasibility study of such an approach which was performed in laboratory conditions. Experimental validation tests were conducted on a setup consisting of a servo-hydraulic test rig equipped with displacement, force and acceleration transducers and a data-acquisition system. The fidelity and adequacy of various parametric SISO model structures were evaluated in the time domain based on correlation coefficient, FPE and AIC criteria. The experimental test results showed that inverse models provide accuracy of inversion, ranging from more than 70% for the ARX model structure to over 90% for the OE model structure.

Keywords: Inverse model, parametric model, passenger vehicle, hydraulic damper

Full paper (PDF, 687kB)