Wyniki wyszukiwania - Biblioteka Nauki

1

Wykorzystanie sygnałów wibroakustycznych w diagnostyce silników samochodowych w teście zimnym

100%

Stelmasiak Z. , Rudnicki M.

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tom nr 3

5983--5990

PL

W artykule przedstawiono nową metodykę wibroakustycznej diagnostyki silnika spalinowego podczas testu zimnego na linii produkcyjnej. Zaprezentowano metody pomiaru i analizy drgań wybranych elementów silnika na podstawie analizy synchronicznej czyli tzw. analizy rzędów. Analizę tę można wykorzystywać do oceny stanu jakościowego całego silnika oraz poszczególnych jego części takich jak: koła zębate, wały, łańcuch rozrządu, układ korbowodowy itp.

EN

This paper presents a new a new methodology for vibroacoustic diagnostics of the internal combustion engine during cold test on the production line. Presented method of the vibration measurement and analysis of selected parts of the engine on the basis of the so-called synchronous order analysis. This analysis can be used to assess the state of qualitative entire engine and its individual parts such as gears, shafts, timing chain, connecting rod etc.

2

Signal conditioning for examination of shallow-water acoustic noise correlation properties

100%

Rudnicki M. , Marszal J.

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tom Vol. 19

335--340

EN

The article describes the process of signal conditioning for examination of acoustic noise correlation properties in shallow water. Knowledge of these properties is very important for the design processes of passive and active hydroacoustic systems. This paper focuses on the above issue from the point of view of passive sonar. In sonar systems, signal processing algorithms operate on both useful acoustic signals, and accompanying noise. Quantitative estimation of the correlation properties of acoustic noise enables an accurate determination of detection conditions. This will verify the validity of certain commonly used simplified models in simulations of hydroacoustic systems. The article presents how the measurement system was constructed, and the structure of files for storing measurement data. It describes the processing algorithm developed for the measured signal conditioning. Research results are presented and discussed.

3

Analiza trójwymiarowego obszaru optymalnych rozwiązań silnika komutatorowego

100%

Puternicki P. , Rudnicki M.

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tom Z. 201

65-78

PL

Opisano możliwości i strukturę systemu Projkryt projektowania silnika komutatorowego małej mocy z zaznaczeniem wprowadzonych uzupełnień w oprogramowaniu tego systemu w celu uzyskiwania pełnego zbioru wartości funkcji celu. Dokonano rozszerzenia analizy jaką daje system Projkryt. Wykorzystano pakiet Matlab do interpolacji funkcji celu wszystkich rozwiązań spełniających nałożone wymagania i ograniczenia. Przedstawiono wyniki optymalizacji dla kilku kryteriów w postaci przestrzennych obszarów charakteryzowanych najlepszym rozwiązaniem i optimami lokalnymi. Omówiono zgodność projektów ocenianych wg różnych kryterów. Stosując przyjęty porządek ważności kryteriów wybrano optymalny projekt.

EN

In the paper the idea of design package PROJKRYT is presented [1, 5, 6]. The implemented method aims at the optimal design of small commutator motors. Special attention is paid on main components of choosing the best design from the set of numerical results [3,7]. The best design is found by varying the magnetic circuit geometry and magnetic saturation of the circuit as well. The quality of magnetic circuit and windings design is checked against technological restrictions using a number of tolerance contraints. Only those designs satisfying all physical requirements are further analysed (Fig. 1,2). The software package Projkryt has been modified to get the whole collection of values of a given criterion. The Matlab package [4] was applied to obtain interpolated values of each criterion in three dimensions. To validate designed motors several criteria expressing different design priorities [5, 7] e.g. minimum cost, minimum volume, maximum torque per unit cost (Fe+Cu) were used. The relevant validation procedure is briefly described. A set of admissible solutions is analysed to find the best design and local optimum points as well [8] (Fig 3) The next step is to review all designs in order to discover potential solutions to the problem. By a potential solution we mean one which meets some extra requirements (e.g. a specified l/D ratio). Such a solution need not be the best one with respect to a given criterion. However, if the order of importance of criteria is fixed, then the solution to the problem is one which optimises the most important criterion. Usually, the above practical optimum is a compromise between best solutions which, in tum, are checked against contradictory criteria (Fig. 4, 5). The quality of final optimal design depends on a number of technological and physical factors: this problem is discussed in the paper. In conclusion, suggestion related to an optimal design verification using deterministic optimisation and/or field analysis are given

4

Detectability of gear damage in combustion engines through a vibroacoustic method

100%

Stelmasiak Z. , Rudnicki M.

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tom R. 53, nr 3

12--22

EN

The paper presents a new methodology in vibroacoustic diagnostics of internal combustion engines during a cold test on the production line. This method utilizes order analysis of harmonic components of vibroacoustic signals taken from a combustion engine driven with an electric motor to identify the source of noise and vibration amplitude. The presented analysis of the harmonic orders was used to diagnose the damage of the gear teeth.

PL

W artykule przedstawiono nową metodykę wibroakustycznej diagnostyki silnika spalinowego podczas testu zimnego na linii produkcyjnej. Wykorzystuje ona analizę rzędową składowych harmonicznych sygnału wibroakustycznego silnika spalinowego napędzanego silnikiem elektrycznym do identyfikacji źródła hałasu i amplitudy drgań. Zaprezentowaną analizę rzędów harmonicznych stosowano do diagnostyki uszkodzeń zębów koła zębatego przekładni silnika spalinowego.

5

System PROJMAT 2000: ranking kryteriów na tle ograniczeń uwikłanych optymalizacji wielokryterialnej silnika komutatorowego małej mocy

100%

Puternicki P. , Rudnicki M.

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tom Z. 208

143-154

PL

W artykule opisano system PROJMAT 2000 do optymalizacji silników komutatorowych małej mocy, oparty na metodzie sekwencyjnego programowania kwadratowego (SQP). System przeznaczony jest do pracy w środowisku pakietu Matlab i służy do optymalizacji wielokryterialnej zgodnie z przyjętym rankingiem kryteriów oceny silnika. System składa się z dwóch głównych modułów: optymalizatora, który znajduje optymalny wektor decyzyjny oraz postprocesora, który na jego podstawie oblicza podstawowe parametry elektromechaniczne silnika. Działanie systemu zademonstrowano na przykładzie optymalnego projektowania silnika 1200 W, 18000 obr/min. Przedstawiono wyniki dla różnych rankingów kryteriów: kosztu materiałów czynnych i sprawności. Zbadano wpływ ograniczeń na realność projektu. Podano rysunek optymalnego obwodu magnetycznego.

EN

In the paper an optimisation system PROJMAT 2000 for optimal design of small commutator motors based on sequential quadratic programming (SQP) is described. The SQP method along with quasi-Newton Hessian matrix update is nowadays recognised as one of the best optimisation algorithms available [1] (Fig. 1). The method is implemented in the Optimization Toolbox of Matlab [8]. The system works in the Matlab 4.2.c package environment and is intended for multicriterion or single optimisation following adopted performance criteria rating. For multicriterion optimisation the method of weighted sum is used. In the above method a multicriterion objective function is set up by introducing a dot product of the weight vector by multicriterion vector (Fig. 2). To reduce numerical effort we project the multicriterion vector onto [0,1] interval using appropriate vector norms. The above results as well in better trade-up between weight vector and multicriterion vector. Moreover, we introduce auxiliary objective sub-functions to have entirely minimisation problem. The PROJMAT 2000 system [5, 6, 7] consists of two main modules: that of optimser which finds an optimum design vector and that of post-processor which, on the basis of found design vector, calculates major electromechanical parameters of the motor. There are also extra subroutines for data handling, graphical processing and so on. Nowadays, the system is capable of handling ten-dimensional design vector subject to 46 constraints including simple bounds and technological ones. The system was elaborated to be friendly for the user to enhance user-system interaction. Huge potential of the PROJMAT 2000 system has been demonstrated for optimal design of a 1200 watt, 18000-rpm commutator motor. We give optimisation results for single and multicriterion optimisation using variable criteria rating: cost and efficiency of the motor (Fig.3). We have explored in detail how imposed constraints influence technical reliability of the project. We analyse compromise optimal solutions found using Pareto front concept. It is shown how the user can select the most suitable design from the infinite many solutions constituting Pareto front. The corresponding optimal magnetic circuit geometry obtained by PROKRYT [2, 3, 4] and PROJMAT 2000 systems is attached (Fig. 4). The final validation of found optimal design would require building a prototype motor. Final conclusions complete the paper.

6

Modern regularization techniques for inverse modelling: a comparative study

80%

Krawczyk-Stańdo D. , Rudnicki M. , Stańdo J.

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tom Vol. 19, nr 1

51-63

EN

Regularization techniques are used for computing stable solutions to ill-posed problems. The well-known form of regularization is that of Tikhonov in which the regularized solution is searched as a minimiser of the weighted combination of the residual norm and a side constraint-controlled by the regularization parameter. For the practical choice of regularization parameter we can use the L-curve approach, U-curve criterion introduced by us [1] and empirical risk method [2]. We present a comparative study of different strategies for the regularization parameter choice on examples of function approximation by radial basis neural networks. Such networks are universal approximators and can learn any nonlinear mapping. e.g. representing an magnetic inverse problem. Some integral equations of the first kind are considered as well.

7

Visual representation of the effects of spatial and frequency filters applied in passive sonars

80%

Raganowicz A. , Salamon R. , Rudnicki M. , Kilian L.

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tom Vol. 4

213--116

EN

The operator of a passive sonar should be able to discern the direction (bearing) of a submerged, noise-producing object. Interference to bearing comes from reverberations, noise from the sea, man-made noise and noise generated by other objects. The article presents methods of spatial and frequency filtration designed to provide various forms of display of those fragments of the spectrum that are of interest to the operator. The operator makes his selection on the basis of many spectrograms that are produced during the successive listening cycles, displayed on the monitor. The amplitudes of spectral lines in the spectrograms are presented as lines of various lengths and colours. The summation spectrum of the displayed listening cycles is presented, too. The lines from a selected spectral range are shown on the panoramic amplitude graph in the function of the bearing angle. Thanks to that the determination of the location of the source of sound is significantly improved. The source of sound can also be discerned by using a reverse technique whereby a group of spectral lines is determined on the basis of a selected sector of angular observation.

8

Przegląd badań dotyczących charakterystyk przepływowych kryz wielootworowych

80%

Kwidzyński R. , Trela M. , Krzemiński E. , Rudnicki M.

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tom T. 48, nr 9

374--379

PL

Przedstawiono najważniejsze opublikowane wyniki badań eksperymentalnych i symulacji numerycznych, dotyczące charakterystyk kryz wielootworowych. Opublikowane wyniki potwierdzają mniejsze straty ciśnienia w przepływie przez kryzy wielootworowe, w porównaniu ze standardową kryzą jednootworową. Natomiast zwiększona odporność pomiarowych kryz wielootworowych na zaburzenia przepływu jest słabo udokumentowana i wymaga dalszych badań.

EN

The paper presents the key published results of experimental research and numerical (CFD) simulations concerning the flow characteristics of multi-hole orifices. Published results confirm reduction of pressure loss in the flow through the multi-holed orifice in comparison to a standard single-hole orifice. However, often quoted increased resistance of measuring multi-hole orifices to the flow disturbances is not adequately documented and needs further investigation.

9

Mutual Clutter Suppression Techniques for FM Sonars

71%

Marszal J. , Rudnicki M. , Jedel A. , Salamon R. , Kochańska I.

Archives of Acoustics

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2016

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tom Vol. 41, No. 4

721--729

EN

The article presents methods that help in the elimination of mutual clutter as well as the consequences of two FM sounding signal sonars operating in the same body of water and frequency band. An in-depth analysis of mutual clutter was carried out. The effects of sounding signal differentiation were determined, as was the Doppler effect on mutual clutter suppression. One of the methods analysed is of particular interest in a situation in which collaborating sonars are operating in opposite frequency modulation directions. This method is effective for both linear and hyperbolic frequency modulations. A formula was derived, identifying exactly how much quantities of clutter may be lessened. The work included comprehensive computer simulations and measurements as well as tests in real-life conditions.

10

Workstation for training ASW helicopter navigators and analysing real flight data

61%

Raganowicz A. , Kilian L. , Marszal J. , Schmidt A. , Sidorko T. , Rudnicki M.

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tom Vol. 12

181-188

EN

The article presents a training and diagnostic workstation designed for Polish Navy ASW helicopter navigators. Installed at the helicopter base, the workstation is used for training and instruction in operating the device and analysing information gathered by navigators during the flight using the ASW onboard sonar, sonobuoy receiver and magnetometer. The workstation allows instructors to task two operators and monitor their performance under conditions resembling those onboard a plane. The tasks involve the operation of the consoles and collecting information during tactical situations, diagnosing damage and analysing flight data in office environment. The objective is to ensure proper helicopter navigator training and experience given the limited possibility of training flights.

11

Multibeam sonar with hexagonal array

51%

Salamon R. , Marszal J. , Kilian L. , Jedel A. , Ostrowski Z. , Raganowicz A. , Rudnicki M. , Wofan Z. , Zachariasz K.

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tom Vol. 2

133--138

EN

The paper presents a multi-beam digital sonar that was designed for monitoring and fish stock assessment in in/and waters. The sonar can also be used as a bottom profiler in lakes, rivers and shallow sea areas. The hexagonal piezoelectric transducer array co-operates with a commutator set. The 32 -channel digital beamformer creates 30 narrow receiving beams in every 60o sector of simultaneous observation. The six sectors cover the whole 360o angle range of the sonar. The beamformer digital signal processing is based on second order sampling of echo signals and the phase-shifting principle of beam deflection. The sonar block diagram, beamformer algorithms, as well as transducers designs are discussed.