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CONTENTS
| Konrad Jędrzejewski, Anatoliy A. Platonov - Analysis of influence of internal converters nonlinearity on intelligent cyclic ADC performance | 343 |
| M. Szmajda, K. Górecki, J. Mroczka, J. Borkowski - Antialiasing filters in power quality digital measurement systems | 355 |
| Waldemar Minkina, Sławomir Gryś - Dynamics of contact thermometric sensors with electric output and methods of its improvement | 371 |
| Adam Woźniak, Marek Dobosz - Research on hysteresis of triggering probes applied in coordinate measuring machines | 393 |
| Grzegorz Pankanin, Jerzy Berliński, R. Chmielewski - Analytical modelling of Karman vortex street | 413 |
| Milos Sedlacek, Michal Krumpholc - Digital measurement of phase difference - a comparative study of DSP algorithms | 427 |
| Hossam Mousa Sidki - Angles measurement of right angle prisms using optical coordinate measuring instrument | 449 |
| Wojciech Toczek, Michał Kowalewski - A neural network based system for soft faults diagnosis in electronic circuits | 463 |
| Janusz Mindykowski - Report on IMEKO TC4 Symposium & ADC Workshop in Gdynia/Jurata, September 2005 | 477 |
ABSTRACTS & FULL PAPERS
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KONRAD JĘDRZEJEWSKI1, ANATOLIY A. PLATONOV2,1
1Warsaw University of Technology
Faculty of Electronics and Information Technology, Poland
e-mail: kala@ise.pw.edu.pl
2Moscow Institute of Electronics and Mathematics, Chair of Cybernetics, Russia
ANALYSIS OF INFLUENCE OF INTERNAL CONVERTERS NONLINEARITY ON INTELLIGENT CYCLIC ADC PERFORMANCE
The task of the paper is the presentation of a modelling approach to quantitative analysis of the influence of internal converter nonlinearities on the performance of sub-optimal intelligent cyclic A/D converters (IC ADCs) developed and analysed in works [1-5] and others. The results of investigations permit to determine requirements to the analogue elements of IC ADC architecture, first of all to an internal low-bit A/D converter (ADCIn), which is the most crucial for the design and practical implementation of IC ADC.
Keywords: cyclic A/D converters, nonlinearity of converters, performance
Full paper (1455kB): M&MS_2005_343.pdf
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M. SZMAJDA1, K. GÓRECKI1, J. MROCZKA2, J. BORKOWSKI2
1Technical University of Opole, Poland
2Technical University of Wroclaw, Poland
e-mail: szmajda@po.opole.pl, janusz.mroczka@pwr.wroc.pl
ANTIALIASING FILTERS IN POWER QUALITY DIGITAL MEASUREMENT SYSTEMS
Digital signal processing exists in the systems which perform the processing of power waveforms. Each measurement equipment using digital signal processing and computing its discrete spectrum should be equipped with an antialiasing filter which unfortunately creates errors in magnitude and phase spectrum responses. This paper discusses the spectrum distortion analysis of the power signals caused by antialiasing filter implementation in the analog-digital signal processing system paths. The influence of the aliasing phenomenon and a real type magnitude response of the antialiasing filter on the measurement uncertainty of the power signal amplitude characteristic was specified. The values of the minimal sampling frequencies for the power signal spectrum computations were proposed. Use of these frequencies assures the maximum error level at the specified level (0,1%, 1% and 10%). The research includes low-pass realization of the filter magnitude responses approximated by polynomials: Butterworth, Bessel, Chebyschev and elliptic.
Keywords: Antialiasing, filters, digital signal processing system, power quality
Full paper (725kB): M&MS_2005_355.pdf
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WALDEMAR MINKINA, SŁAWOMIR GRYŚ
Czestochowa University of Technology
Institute of the Electronics and Control Systems, Poland
e-mail: minkina@el.pcz.czest.pl
DYNAMICS OF CONTACT THERMOMETRIC SENSORS WITH ELECTRIC OUTPUT AND METHODS OF ITS IMPROVEMENT
The paper deals with selected aspects of modelling dynamic properties of contact thermometric sensors and reducing the dynamic error occurring in measurement of time-variable temperature as well as in measurement of constant temperature while the sensor output is settling. Due to volume limitations the paper is only an outline and presents some problems superficially. An attempt to present a wider study on the subject with rich bibliography is presented in the authors' monograph [1].
Keywords: thermometer sensor, dynamic properties, correction algorithms
Full paper (363kB): M&MS_2005_371.pdf
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ADAM WOŹNIAK, MAREK DOBOSZ
Warsaw University of Technology
Institute of Metrology and Measuring Systems, Poland
e-mail: dobosz@mchtr.pw.edu.pl
RESEARCH ON HYSTERESIS OF TRIGGERING PROBES APPLIED IN COORDINATE MEASURING MACHINES
The article presents selected results of investigation of triggering probe hysteresis in coordinate measuring machines. The research covered the hysteresis of pretravel of one-stage triggering probes equipped with a switching transducer (represented by TP6 probe), and two-stage probes equipped with a piezoelectric transducer (e.g. TP200 probe). The effects of stylus length, measurement pressure and approach speed to the measured surface have been included in the performed tests. The variance analysis methods have been used to evaluate the effects. The results, obtained in various conditions and using different probes, have been compared. As a result, optimum values of tested parameters have been estimated, as far as they concern the operation accuracy of the probe.
Keywords: coordinate measuring machine (CMM), triggering probe
Full paper (273kB): M&MS_2005_393.pdf
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G.L. PANKANIN, J. BERLIŃSKI, R. CHMIELEWSKI
Warsaw University of Technology
Institute of Electronic Systems, Poland
e-mail: g.pankanin@ise.pw.edu.pl
ANALYTICAL MODELLING OF KARMAN VORTEX STREET
A new approach to the Karman vortex street modelling is presented. The model is based on observations of the Karman vortex street. The idea of the model is based on fundamental mechanical formulas. According to the model, vortices are created on the bluff body surface in the area of the boundary separation. The grow-up of the vortex results from the process looking like a reeling of some amount of the liquid on the vortex core during its rolling downstream on the surface of unmoved stagnation region. This process is represented in the model as a succeeding addition layer attachment. The vortex evolution has been divided into three stages. Hence three zones downstream the bluff body are distinguished: intensive development, stabilization and vortices decay. Influence of the fluid viscosity on the development process and rotation energy of the vortex has been also analyzed.
Keywords: numerical modelling, Karman vortex street, vortex meter
Full paper (215kB): M&MS_2005_413.pdf
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MILOS SEDLACEK, MICHAL KRUMPHOLC
Czech Technical University in Prague
Faculty of Electrical Engineering, Czech Republic
e-mail: sedlaceM@fel.cvut.cz
DIGITAL MEASUREMENT OF PHASE DIFFERENCE - A COMPARATIVE STUDY OF DSP ALGORITHMS
The paper compares nine methods of measurement of the phase difference of digitized sinusoidal signals mainly according to their sensitivity to sampling non-integer number of signal periods. The investigated methods can be classified into four groups - modifications of classical zero-crossing based measurements, virtual vector voltmeter, DFT-based measurements, and modifications of sine-wave fit algorithm. Results of both simulations and measurements are presented.
Keywords: phase difference measurement, DSP algorithms of phase diffence estimation
Full paper (742kB): M&MS_2005_427.pdf
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HOSSAM MOUSA SIDKI
National Institute of Standards
Laboratory of Engineering and Precise Optics
Tersa Street, El-Haram, Giza 12211, Egypt
e-mail: hossamsidki@yahoo.com
ANGLE MEASUREMENT OF RIGHT ANGLE PRISMS USING OPTICAL COORDINATE MEASURING INSTRUMENT
A new technique for calibrating the angles of right angle prisms using an optical coordinate measuring instrument is presented in this work. The technique is an optical non-contact method that is based on focusing of images of the measured elements. Measurements of the angles of optical components are very important since they affect the accuracy and precession of the measurement techniques. The results and their uncertainties show the validity of the method.
Keywords: Right angle prism, angle measurement, optical coordinate measuring instrument
Full paper (607kB): M&MS_2005_449.pdf
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WOJCIECH TOCZEK, MICHAŁ KOWALEWSKI
Gdansk University of Technology
Faculty of Electronics Telecommunication and Informatics, Poland
e-mail: Wojciech.Toczek@eti.pg.gda.pl
A NEURAL NETWORK BASED SYSTEM FOR SOFT FAULT DIAGNOSIS IN ELECTRONIC CIRCUITS
The paper considers the architecture and the main steps of development of a neural network based system for diagnosis of soft faults in analog electronic circuits. The definition of faults of interest, selection of an optimal set of measurements, feature extraction, the construction of the artificial neural network, training and testing the network, are considered. A fault dictionary method was implemented in the system. Experimental results are presented on an example of diagnosis of a 6-th order bandpass filter. The measuring part of the system performs input-output measurements in the frequency domain with the aid of a HP 4192 Transmitance Analyzer.
Keywords: analog fault diagnosis, fault dictionary, artificial neural networks, soft-faults
Full paper (499kB): M&MS_2005_463.pdf
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