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CONTENTS
| 1. W. Nawrocki - Review Paper. The quantum SI - towards the new system of unit | 139 |
| 2. K. Fukuda, K. Yoshida, T. Kinugasa, M. Kamon, Y. Kagawa, T. Ono - A new method of mass measurement for checkweighers | 151 |
| 3. Z. Zhaoxuan, W. Houjun, W. Zhigang, Z. Hao - A reconstruction method of generalized sampling based on generalized inverse | 163 |
| 4. P.A. Almeida Magalhaes Jr, P. Smith Neto, C. Almeida Magalhães - New Carré Equation | 173 |
| 5. M. Catelani, A. Zanobini, L. Ciani - Uncertainty interval evaluation using the Chi-square and Fisher distributions in the measurement process | 195 |
| 6. Z. Ming, L. Kaicheng, H. Yisheng - DSP-FPGA beads real-time power quality disturbances classifier | 205 |
| 7. E. Pinheiro, O. Postolache, P. Girão - Fixed-point implementation of infinite impulse response notch filters | 217 |
| 8. S. Adamczak, W. Makie³a, K. Stêpieñ - Investigating advantages and disadvantages of the analysis of a geometrical surface structure with the use of Fourier and wavelet transform | 233 |
| 9. P. Burnos, J. Gajda, P. Maj - Digital system for detection and location of miners trapped in hard coalmines - GLOP2 | 245 |
| 10. P.M. Ramos, F.M. Janeiro, T. Radil - Comparative analysis of three algorithms for two-channel common frequency sinewave parameter estimation: ellipse fit, seven parameter sine fit and spectral sinc fit | 255 |
| 11. M. Wieczorowski, R. Mrozek, P. Andra³ojæ - The use of surface asperities analysis to investigate wear of bodies in contact on example of brake elements | 271 |
| 12. T. Janiczek, J. Janiczek - Linear dynamic system identification in the frequency domain using fractional derivatives | 279 |
| 13. W. Susek, B. Stec - Broadband microwave correlator of noise signals | 289 |
| 14. A. ¯uchowski - On a certain class of expanding systems | 299 |
| 15. J. Mroczka - Short Note. Jerzy Barzykowski - the 80th anniversary | |
ABSTRACTS & FULL PAPERS
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Review Paper
THE QUANTUM SI - TOWARDS THE NEW SYSTEM OF UNIT
Waldemar Nawrocki
Poznan University of Technology, Faculty of Electronics and Telecommunications, Polanka 3, 60-965 Poznan, Poland (nawrocki@et.put.poznan.pl, +48 61 665 3888)
Abstract
The possibility or even necessity of revising definitions of some of the base units of the present SI has been discussed over the past 15 years. The last General Conference of Weights and Measures (2007) recommended to redefine the kilogram, the ampere, the kelvin, and the mole using fixed values of the fundamental constants by the time of the next General Conference in 2011. This paper is a review of proposals of new definitions of units of mentioned quantities and arguments voting for particular variants of definitions. Most relevant paper for this review have been published by Metrologia, the international journal appointed at the BIPM, and many other useful pieces of information are avaible on www pages of the BIPM. The author notes that not only new definitions have been discussed but as well as the set of the base units of the SI. It means a replacement the ampere by the volt or the kelvin by the joule. Decisions concerning new definitions are not made and the discussions are still open.
Keywords: SI system, base units, quantum standards.
© 2010 Polish Academy of Sciences. All rights reserved
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A NEW METHOD OF MASS MEASUREMENT FOR CHECKWEIGHERS
Kengo Fukuda1), Koji Yoshida2), Tetsuya Kinugasa3), Morihito Kamon4), Yoichiro Kagawa5), Toshiro Ono 6)
1) Oyo Measurement Co., Ltd, 2-12-6, Esaka-cho, Suita, Osaka 564-0063, Japan (k5-fukuda@mvd.biglobe.ne.jp)
2) Okayama University of Science, Department of Mechanical Systems Engineering, 1-1 Ridai-cho, Kita-ku, Okayama-city, Okayama 700-0005, Japan (k_yoshida@mech.ous.ac.jp, +81 86 256 9743)
3) Okayama University of Science, Department of Mechanical Systems Engineering, , 1-1 Ridai-cho, Kita-ku, Okayama-city, Okayama 700-0005, Japan (kinugasa@mech.ous.ac.jp)
4) Yamato Scale Co., Ltd., Department of Automatic Machinery R&D, 5-22, Saenba-cho, Akashi, Hyogo, 673-8688, Japan (kamon-m@yamato-scale.co.jp)
5) Yamato Scale Co., Ltd., Department of Automatic Machinery R&D, 5-22, Saenba-cho, Akashi Hyogo, 673-8688, Japan (kagawa-y@yamato-scale.co.jp)
6) Osaka Prefecture University, 1-1 Gakuen-cho,Nakaku,Sakai,Osaka 599-8531,Japan ( t-ono@s9.dion.ne.jp)
Abstract
A checkweigher is an automatic machine to measure the weight of in-motion products. It is usually located around the end of the production process and ensures the weight of a product within specified limits. Any products are taken out of line if their weights are out of the specified limits. It is usually equipped with an optical device. It is used to make a trigger to set the time duration to allow a product to move completely on the weigh belt for sampling the weight. In this paper, a new method of mass measurement for checkweighers is proposed which uses just signal processing without the optical device. The effectiveness of the method is shown through experiments. Also a possibility of faster estimation of weight is shown.
Keywords: checkweigher, weighing method, signal processing, high accuracy.
© 2010 Polish Academy of Sciences. All rights reserved
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A RECONSTRUCTION METHOD OF GENERALIZED SAMPLING BASED ON GENERALIZED INVERSE
Zhu Zhaoxuan, Wang Houjun, Wang Zhigang, Zhang Hao
University of Electronic Science and Technology of China, The College of Automation Engineering, Chengdu, Sichuan, 611731, China (zhaoxuanzhu@uestc.edu.cn, +86 28 618 31307, hjwang@uestc.edu.cn, wangzhigang@uestc.edu.cn, ccscmt@163.com)
Abstract
This paper considers the problem of reconstructing a class of generalized sampled signals of which a special case occurs in, e.g., a generalized sampling system due to non-ideal analysis basis functions. To this end, we propose an improved reconstruction system and a reconstruction algorithm based on generalized inverse, which can be viewed as a reconstruction method that reduces reconstruction error as well. The key idea is to add an additional channel into a generalized sampling system and apply the generalized inverse theory to the reconstruction algorithm. Finally, the approach is applied, respectively, to an oscilloscope, which shows the proposed method yields better performance as compared to the existing technique.
Keywords: Hilbert space, generalized sampling, reconstruction, generalized inverse.
© 2010 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 363kB) |
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NEW CARRÉ EQUATION
Pedro Americo Almeida Magalhaes Junior, Perrin Smith Neto, Cristina Almeida Magalhães
Pontificia Universidade Catolica de Minas Gerais, Av. Dom Jose Gaspar 500, CEP 30535-610, Belo Horizonte, Minas Gerais, Brazil (paamj@oi.com.br, +55 31 3221 6813, psmith@pucminas.br, crisamagalhaes@hotmail.com)
Abstract
The present work offers new equations for phase evaluation in measurements. Several phase-shifting equations with an arbitrary but constant phase-shift between captured intensity signs are proposed. The equations are similarly derived as the so called Carré equation. The idea is to develop a generalization of the Carré equation that is not restricted to four images. Errors and random noise in the images cannot be eliminated, but the uncertainty due to their effects can be reduced by increasing the number of observations. An experimental analysis of the errors of the technique was made, as well as a detailed analysis of errors of the measurement. The advantages of the proposed equation are its precision in the measures taken, speed of processing and the immunity to noise in signs and images.
Keywords: metrology, Moiré techniques, fringe analysis, phase measurement, phase shifting technique, Carré equation.
© 2010 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 545kB)
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UNCERTAINTY INTERVAL EVALUATION USING THE CHI-SQUARE AND FISHER DISTRIBUTIONS IN THE MEASUREMENT PROCESS
Marcantonio Catelani, Andrea Zanobini, Lorenzo Ciani
University of Florence, Department of Electronics and Telecommunications, Via di Santa Marta 3, 50139, Florence, Italy(marcantonio.catelani@unifi.it, +39 55 479 6377, andrea.zanobini@unifi.it, lorenzo.ciani@unifi.it)
Abstract
Referring to the Guide to the Expression of Uncertainty in Measurement (GUM), the paper proposes a theoretical contribution to assess the uncertainty interval, with relative confidence level, in the case of n successive observations. The approach is based on the Chi-square and Fisher distributions and the validity is proved by a numerical example. For a more detailed study of the uncertainty evaluation, a model for the process variability has been also developed.
Keywords: measurement uncertainty, confidence level, statistical distributions.
© 2010 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 401kB)
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DSP-FPGA BASED REAL-TIME POWER QUALITY DISTURBANCES CLASSIFIER
Zhang Ming , Li Kaicheng, Hu Yisheng
Huazhong University of Science and Technology, Department of Electrical and Electronic Engineering, Wuhan 430074, Hubei Province, China (zmcock@yahoo.com.cn, +86 0278 754 3628, likaicheng@mail.hust.edu.cn, hu_yisheng@powercipro.com)
Abstract
This paper describes a real-time classification method of power quality (PQ) disturbances based on DSP-FPGA. The proposed method simultaneously uses the results obtained in the application of a series of RMS values and the discrete Fourier transform to the power signal waveform. A series of RMS values are used for estimation of the time-related parameters of the PQ disturbances and the discrete Fourier transform is used for confirmation of the frequency-related parameters of the PQ disturbances. Without adding the computational burden, both the elementary parameters of the power signal and the type of PQ disturbance are obtained easily. A simple and effective methodology for classification of nine typical kinds of PQ disturbances is proposed in this paper. Five distinguished time-frequency statistical features of each type of PQ disturbances are extracted. Using a rule-based decision tree (RBDT), the PQ disturbances pattern can be recognized easily and there is no need to use other complicated classifiers. Finally, the method is also tested using both simulated disturbances and disturbances measured using an initial development instrument. Different experimental results show the good performance of this proposed approach. Real-time calculating time based on DSP is also taken into consideration to show the effectiveness of the proposed method.
Keywords: Discrete Fourier transform, power quality disturbances, real-time classifier, RMS, rule-based decision tree.
© 2010 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 850kB)
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FIXED-POINT IMPLEMENTATION OF INFINITE IMPULSE RESPONSE NOTCH FILTERS
Eduardo Pinheiro1), Octavian Postolache2), Pedro Girão1)
1) Instituto de Telecomunicações and Instituto Superior Técnico, Av. Rovisco Pais, 1, 1049-001 Lisbon, Portugal (eduardo.pinheiro@lx.it.pt, p.girão@lx.it.pt, +351 218 418 454)
2) Instituto de Telecomunicações and Instituto Politécnico de Setúbal, Campus do IPS, Estefanilha, 2910-761 Setubal, Portugal (opostolache@lx.it.pt)
Abstract
Many studies have been developed aiming to improve digital filters realizations, recurring to intricate structures and analyzing probabilistically the error´s behaviour. The work presented in this paper analyzes the feasibility of fixed-point implementation of classical infinite impulse response notch filters: Butterworth, Chebyshev I and II, and elliptic. To scrutinize the deformations suffered for distinct design specifications, it is assessed : the effect of the quality factor and normalized cut-off frequency, in the number of significant bits necessary to represent the filter's coefficients. The implications brought to FPGA implementation are also verified.
The work focuses especially on the implementation of power line notch filters used to improve the signal-to-noise ratio in biomedical signals. The results obtained, when quantizing the digital notch filters, show that by applying second-order sections decomposition, low-order digital filters may be designed using only part of double precision capabilities. High-order notch filters with harsh design constraints are implementable using double precision, but only in second-order sections. Thus, it is revealed that to optimize computation time in real-time applications, an optimal digital notch filter implementation platform should have variable arithmetic precision.
Considering these implementation constraints, utmost operation performance is finally estimated when implementing digital notch filters in Xilinx Virtex-5 field-programmable gate arrays. The influence of several design specifications, e.g. type, and order, in the filter's behavior was evaluated. Specifically regarding order, type, input and coefficient number of bits, quality factor and cut-off frequency. Finally the implications and potential applications of such results are discussed.
Keywords: digital filter implementation, digital filter word length effects, notch digital filters.
© 2010 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 637kB)
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INVESTIGATING ADVANTAGES AND DISADVANTAGES OF THE ANALYSIS OF A GEOMETRICAL SURFACE STRUCTURE WITH THE USE OF FOURIER AND WAVELET TRANSFORM
Stanis³aw Adamczak, W³odzimierz Makie³a, Krzysztof Stêpieñ
Kielce University of Technology, Faculty of Mechatronics and Machinery Design, Al. 1000-lecia P.P. 7, 25-314 Kielce, Poland (adamczak@tu.kielce.pl, wmakiela@tu.kielce.pl, kstepien@tu.kielce.pl, +48 41 342 4477)
Abstract
Nowadays a geometrical surface structure is usually evaluated with the use of Fourier transform. This type of transform allows for accurate analysis of harmonic components of surface profiles. Due to its fundamentals, Fourier transform is particularly efficient when evaluating periodic signals. Wavelets are the small waves that are oscillatory and limited in the range. Wavelets are special type of sets of basis functions that are useful in the description of function spaces. They are particularly useful for the description of non-continuous and irregular functions that appear most often as responses of real physical systems. Bases of wavelet functions are usually well located in the frequency and in the time domain. In the case of periodic signals, the Fourier transform is still extremely useful. It allows to obtain accurate information on the analyzed surface. Wavelet analysis does not provide as accurate information about the measured surface as the Fourier transform, but it is a useful tool for detection of irregularities of the profile. Therefore, wavelet analysis is the better way to detect scratches or cracks that sometimes occur on the surface. The paper presents the fundamentals of both types of transform. It presents also the comparison of an evaluation of the roundness profile by Fourier and wavelet transforms.
Keywords: wavelet, Fourier transform, geometrical surface structure.
© 2010 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 786kB)
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DIGITAL SYSTEM FOR DETECTION AND LOCATION OF MINERS TRAPPED IN HARD COALMINES - GLOP2
Piotr Burnos, Janusz Gajda, Piotr Maj
AGH University of Science and Technology, Department of Instrumentation and Measurements, Al. Mickiewicza 30, 30-059 Cracow, Poland (burnos@agh.edu.pl, jgajda@agh.edu.pl, 48 12 617 3972, piotr.maj@agh.edu.pl)
Abstract
Paper deals with the new localizer GLOP2 designed for detection of the miners trapped in underground hard coal mines. The results of a field test conducted in coal mine BOBREK show that the presented localizer allows for efficient measurement of the distance between a trapped miner and the rescuer in the range of up to 15 m.
Keywords: hard coal mines, rescue systems, communication systems, trapped miner localizer.
© 2010 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 583kB)
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COMPARATIVE ANALYSIS OF THREE ALGORITHMS FOR TWO-CHANNEL COMMON FREQUENCY SINEWAVE PARAMETER ESTIMATION: ELLIPSE FIT, SEVEN PARAMETER SINE FIT AND SPECTRAL SINC FIT
Pedro M. Ramos1), Fernando M. Janeiro2), Tomáš Radil3)
1) Instituto de Telecomunicaçoes, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal (Pedro.Ramos@Lx.it.pt, +351 21 841 8485)
2) Instituto de Telecomunicaçoes, Universidade de Évora, Rua Romao Ramalho 59, 7000-671 Évora, Portugal (fmtj@uevora.pt)
3) Instituto de Telecomunicaçoes, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal ( Tomas.Radil@Lx.it.pt)
Abstract
In this paper, a comparison analysis of three different algorithms for the estimation of sine signal parameters in two-channel common frequency situations is presented. The relevance of this situation is clearly understood in multiple applications where the algorithms have been applied. They include impedance measurements, eddy currents testing, laser anemometry and radio receiver testing for example. The three algorithms belong to different categories because they are based on different approaches. The ellipse fit algorithm is a parametric fit based on the XY plot of the samples of both signals. The seven parameter sine fit algorithm is a least-squares algorithm based on the time domain fitting of a single tone sinewave model to the acquired samples. The spectral sinc fit performs a fitting in the frequency domain of the exact model of an acquired sinewave on the acquired spectrum. Multiple simulation situations and real measurements are included in the comparison to demonstrate the weaknesses and strong points of each algorithm.
Keywords: sinewave parameter estimation, amplitude and phase measurements, seven parameter sine fit, ellipse fit, spectral sinc fit.
© 2010 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 1991kB)
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THE USE OF SURFACE ASPERITIES ANALYSIS TO INVESTIGATE WEAR OF BODIES IN CONTACT ON EXAMPLE OF BRAKE ELEMENTS
Micha³ Wieczorowski1), Robert Mrozek2), Pawe³ Andra³ojæ1)
1) Poznan University of Technology, Faculty of Mechanical Engineering and Management, Institute of Mechanical Technology, Piotrowo 3, 60-965 Poznan, Poland (michal.wieczorowski@put.poznan.pl, andralojc.pawel@gmail.com, +48 61 665 3569)
2) SAF-Holland Polska sp. z o.o, 27 Stycznia 42/43, 64-980 Trzcianka, Poland (robert.mrozek@wp.pl)
Abstract
The use of surface analysis to investigate brake elements shows how a pair in contact works and wears out during regular operation. The main purpose of this paper is to describe the asperities from initial state to a moment when further use of the drum and shoe is not possible. Between exchange of vital brake elements a truck with total mass exceeding 3.5 tons can cover as many as 300 000 kilometres. Use of brakes during the first 1000 kilometres after maintenance should be rather gentle with possibly intensive use of engine brake installed in the truck itself, because if this rule is not adhered to it may lead to a significant decrease of the braking force and on the surface of the pair in contact a layer will appear that is not possible to wear off and that will make it impossible to stop a truck using brakes. In that condition the shoe should be immediately replaced and the drum should be remachined (by turning) to a repair dimension. In the paper the condition and analysis of a surface after different course of exploitation was presented.
Keywords: brake system, surface wear, surface topography.
© 2010 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 4012kB)
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LINEAR DYNAMIC SYSTEM IDENTIFICATION IN THE FREQUENCY DOMAIN USING FRACTIONAL DERIVATIVES
Tomasz Janiczek1), Janusz Janiczek2)
1) Wroclaw University of Technology, Department of Electronics, The Institute of Computer Engineering, Control and Robotics, Z. Janiszewskiego 11/17, 50-372 Wroclaw, Poland (tomasz.janiczek@pwr.wroc.pl)
2) Wroclaw University of Technology, Department of Electronics, Chair of Electronic and Photonic Metrology, B. Prusa 53/55, 51-317 Wroclaw, Poland. (janusz.janiczek@pwr.wroc.pl, +48 71 320 6290)
Abstract
This paper presents a study of the Fourier transform method for parameter identification of a linear dynamic system in the frequency domain using fractional differential equations. Fundamental definitions of fractional differential equations are briefly outlined. The Fourier transform method of identification and their algorithms are generalized so that they include fractional derivatives and integrals.
Keywords: fractional differential equations, fractional differential systems, Fourier transform method, identification methods.
© 2010 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 361kB)
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BROADBAND MICROWAVE CORRELATOR OF NOISE SIGNALS
Waldemar Susek, Bronis³aw Stec
Military University of Technology, Faculty of Electronics, Institute of Radioelectronics, Kaliskiego 2, 00-908 Warsaw, Poland (Waldemar.Susek@wel.wat.edu.pl, +48 22 683 9831, Bronislaw.Stec@wel.wat.edu.pl)
Abstract
A real narrowband noise signal representation in the form of an analytical signal in the Hilbert space is presented in the paper. This analytical signal is illustrated in a variable complex plane as a mark with defined amplitude, phase, pulsation and instantaneous frequency. A block diagram of a broadband product detector in a quadrature system is presented. Measurement results of an autocorrelation function of a noise signal are shown and the application of such solution in a noise radar for precise determination of distance changes as well as velocities of these changes are also presented. Conclusions and future plans for applications of the presented detection technique in broadband noise radars bring the paper to an end.
Keywords: noise signal, correlation receiver, Hilbert space.
© 2010 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 1348kB)
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ON A CERTAIN CLASS OF EXPANDING SYSTEMS
Adam ¯uchowski
West Pomeranian University of Technology, Faculty of Electrical Engineering, 26 Kwietnia 10, 71-126 Szczecin, Poland (chlod@ps.pl, +48 91 449 5411)
Abstract
The interesting properties of a class of expanding systems are discussed. The operation of the considered systems can be described as follows: the input signal is processed by a linear dynamic converter in subsequent time intervals, each of them is equal to Ti. Processing starts at the moments nTi, always after zeroing of converter initial conditions. For smooth input signals and a given transfer function of the converter one can suitably choose Ti and the gain coefficient in order to realize the postulated linear operations on input signals, which is quite different comparing it to the operation realized by the converter. The errors of postulated operations are mainly caused by non-smooth components of the input signal. The principles for choice of system parameters and rules for system optimization are presented in the paper. The referring examples are attached too.
Keywords: Expanding Systems, conditions and accuracy of action.
© 2010 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 930kB)
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