Wyniki wyszukiwania - BazTech

1

The DIA-method for navigational integrity

Teunissen P. J. G.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2023

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Vol. 17 No. 1

157--161

EN

In this contribution we present a review of the DIA-method to ensure navigational integrity. The DIA-method rigorously combines parameter estimation and statistical testing for the Detection, Identification and Adaptation of multivariate and multiple model misspecifications. We describe the statistical properties of the so-obtained DIA-estimator together with its probability density function. Numerical examples are given to highlight various aspects of the navigational DIA-estimator.

2

Odtwarzanie położenia wału dla prędkości zerowej w napędzie z PMSM z użyciem analizy głównych składowych

Urbański Konrad, Janiszewski Dariusz

Przegląd Elektrotechniczny

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2023

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R. 99, nr 5

237--242

PL

W pracy przedstawiono sposób odtwarzania położenia wału silnika synchronicznego z magnesami trwałymi z wykorzystaniem dodatkowego prądu wysokiej częstotliwości. Uzyskany hodograf tego prądu przetwarzany jest z użyciem analizy głównych składowych. Rezultatem przetwarzania jest informacja o poziomie dopasowania do poszczególnych wzorców. Wzorzec o najlepszym dopasowaniu określa odtworzone położenie wału maszyny. Badania zostały przeprowadzone z użyciem danych pomiarowych laboratoryjnego układu napędowego z PMSM.

EN

This paper presents a method of estimating the shaft position of a permanent magnet synchronous motor using an additional high-frequency current. The resulting hodograph of this current is processed using principal component analysis. The result of the processing is information about the level of fit to individual patterns. The pattern with the best match determines the estimated shaft position. The research was carried out using measurement data of a laboratory drive with a PMSM.

3

Estimation of synchronous generator and AVR parameters based on gradient and genetic methods

Dobrzyński Krzysztof

Przegląd Elektrotechniczny

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2023

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R. 99, nr 6

88--92

EN

The author present a method for the estimation of selected synchronous generator model and AVR parameters using a gradient and a genetic algorithm. The paper shows an example of model parameter estimation for a turbogenerator, based on the generator voltage time responses obtained during an active and reactive power rejection test.

PL

Autor przedstawia metodę estymacji wybranego modelu generatora synchronicznego i parametrów AVR z wykorzystaniem algorytmu gradientowego i genetycznego. W artykule przedstawiono przykład estymacji parametrów modelu turbogeneratora w oparciu o odpowiedzi napięciowe generatora uzyskane podczas testu zrzutu mocy czynnej i biernej.

4

Frequentist inference on traffic intensity of M/M/1 queuing system

Dutta Kaustav, Choudhury Amit

Operations Research and Decisions

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2023

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Vol. 33, No. 1

21--34

EN

When we study any queuing system, the performance measures reflect different features of the system. In the classical M/M/1 queuing system, traffic intensity is perhaps the most important performance measure. We propose a fresh and simple estimator for the same and show that it has nice properties. Our approach is frequentist. This approach has the dual advantage of practical usability and familiarity. Our proposed estimator is attractive as it possesses desirable properties. We have shown how our estimator lends itself to testing of hypothesis. Confidence intervals are constructed. Sample size determination is also discussed. A comparison with a few similar estimators is also performed.

5

A neural network for monitoring and characterization of buildings

Romańska-Zapała Anna, Dudzik Marek, Kuc Sabina

Inżynieria Bezpieczeństwa Obiektów Antropogenicznych

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2023

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Nr 4

134--143

EN

This paper continues work from part 1 where a high precision estimator for energy efficiency and indoor environment based on artificial neural networks (ANN) was examined. Part 1 demonstrated that creating a precise representation of a mathematical relationship one must evaluate the stability and fitness under randomly changing initial conditions. Now, we extend our requirements for the model to be rapid and precise. At the end of this work we obtain a road map for the design and evaluation of ANN-based estimators of the given performance aspect in a complex interacting environment. This paper also shows that ANN system designed may have a high precision in characterizing the response of the building exposed to variable outdoor climatic conditions. The absolute value of the relative errors, MaxAR, is less than 2%. It proves that monitoring and ANN-based characterization approach can be used for different buildings, including those with the best environmental performance.

6

Fault diagnosis-based observers using Kalman filters and Luenberger estimators: Application to the pitch system fault actuators

Zemali Zakaria, Cherroun Lakhmissi, Hadroug Nadji, Nadour Mohamed, Hafaifa Ahmed

Diagnostyka

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2023

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Vol. 24, No. 1

art. no. 2022110

EN

This paper aims to present a robust fault diagnosis structure-based observers for actuator faults in the pitch part system of the wind turbine benchmark. In this work, two linear estimators have been proposed and investigated: the Kalman filter and the Luenberger estimator for observing the output states of the pitch system in order to generate the appropriate residual between the measured positions of blades and the estimated values. An inference step as a decision block is employed to decide the existence of faults in the process, and to classify the detected faults using a predetermined threshold defined by upper and lower limits. All actuator faults in the pitch system of the horizontal wind turbine benchmark are studied and investigated. The obtained simulation results show the ability of the proposed diagnosis system to determine effectively the occurred faults in the pitch system. Estimation of the output variables is effectively realized in both situations: without and with the occurrence of faults in the studied process. A comparison between the two used observers is demonstrated.

7

Estimation of fuel consumption in a jet engine based on vibration signal parameters

Szymański Grzegorz M., Cywka Bartłomiej, Mokrzan Daniel, Prokopowicz Wojciech

Combustion Engines

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2023

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R. 62, nr 3

13--20

EN

This paper proposes the use of vibroacoustic signal parameters to estimate the fuel consumption of a miniature GTM-400 engine. The method for testing engine vibrations is presented, followed by an analysis of the results obtained. Two vibration point measures were selected to build a fuel consumption model. The models obtained were verified, after which those that best describe the real fuel consumption of the engine were selected. The paper proves that the vibration signal, in addition to its applications in jet engine diagnostics, can be used to determine engine performance, which can contribute to reducing the complexity of construction and increasing the economics of engine operation.

8

Mineralogical analysis of iron ore using ultrasonic wave propagation parameters

Morkun Natalia, Fischerauer Gerhard, Tron Vitalii, Gaponenko Alona

Acta Mechanica et Automatica

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2023

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Vol. 17, no. 3

364--371

EN

Availability, relative simplicity and low cost, combined with ever-increasing capabilities, have led to a significant increase in the use of ultrasonic measurements of mining process variables in recent times. The scope of application varies from the study of the characteristics of raw materials and products of its processing to the operational assessment of the current parameters characterising the state of the process equipment. The purpose of this study is to develop methods for obtaining information about the characteristics of mineral raw materials as a result of ultrasonic logging of wells in a rock mass. The proposed approach makes it possible to improve the quality of information support for the management of technological processes of mining and processing of ore and thereby improve the quality of products supplied to the metallurgical stage and reduce overall production costs.

9

Estymacja kosztów energii elektrycznej w instalacjach z oprawami drogowymi led

Krukowski Marek, Popławski Tomasz, Krukowski Bartosz

Rynek Energii

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2022

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Nr 2

61--68

PL

W 2006 roku oświetlenie odpowiadało za 19 proc. światowego zużycia energii elektrycznej czynnej. Dzięki inwestycjom w oprawy LED w ciągu 12 lat udział ten spadł do 13 proc., a w 2030 roku powinien osiągnąć pułap 8 proc. Autorzy przedstawiają, na przykładzie wybranego miasta (ilość mieszkańców ponad 100 000) koncepcję realizacji tej idei opartej na wymianie 1:1 - oprawy ze źródłami LED w miejsce opraw wyładowczych. Opisują metodologię tej wymiany oraz zaimplementowanie systemów sterowania. Na podstawie pomiarów parametrów elektrycznych opraw, przedstawiają estymowane koszty zużycia składowych energii elektrycznej w ciągu roku. Dokonują także oceny efektywności energetycznej analizowanej instalacji ze sterowaniem zegarami astronomicznymi.

EN

In 2006, lighting was responsible for 19 percent. global active electricity consumption. Thanks to investments in LED luminaires, this share has dropped to 13% within 12 years, and in 2030 it should reach the level of 8%. The authors present, based on the example of a selected city (population over 100,000), the concept of implementing this idea based on the 1: 1 exchange - luminaires with LED sources in place of discharge luminaires. They describe the methodology of this exchange and the implementation of control systems. Based on the measurements of electrical parameters of luminaires, they present the estimated costs of consumption of electrical energy components during the year. They also assess the energy efficiency of the analyzed installation with the control of astronomical clocks.

10

Wykorzystanie wejściowych map głębi w estymacji głębi po stronie dekodera

Klóska Dominika, Szydełko Błażej, Mieloch Dawid

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2022

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nr 4

392--395

PL

Artykuł opisuje usprawnienia procesu estymacji map głębi po stronie dekodera wizji wszechogarniającej. W prezentowanej propozycji mapy głębi są przesyłane tylko dla części widoków, umożliwiając znaczące zmniejszenie czasu wymaganego na estymację geometrii przy jednoczesnym zwiększeniu jej jakości. Rozwiązanie obejmuje modyfikację oprogramowania ISO/IEC MPEG służącego do wyznaczania geometrii sceny oraz implementacji kodera MPEG Immersive Video. Wyniki testów obejmują porównanie czasu dekodowania i uzyskiwanych prędkości bitowych.

EN

This paper presents a proposal to improve the depth estimation process performed in decoder-side depth estimation. In the proposed solution, depth maps are sent only for a part of the views, allowing a significant reduction in the time required for geometry estimation and a simultaneous increase of its quality. The solution includes the modification of the ISO/IEC MPEG Video Coding software for depth estimation and the implementation of the MPEG Immersive Video encoder. The test results consist of the comparison of decoding times and required bitrates.

11

Geometryczne środki terenu i ich znaczenie

Bednarek Stanisław

Przegląd Geodezyjny

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2022

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R. 94, nr 8

19--24

PL

W artykule podano definicje geometrycznych środków terenu i opisano metody obliczania ich współrzędnych. Podano również współrzędne geograficzne geometrycznych środków terytorium Polski i ich zmiany. W drugiej części artykułu przedyskutowano położenie środków terenu i ich znaczenie praktyczne na przykładach terenów o różnym kształcie.

EN

Definition of the geometric centers of a area are given and methods o their coordinates computations are described in this article. Geographic coordinates of the geometric centers of Poland territory are also given. Geometric centers localization and their practical significance are discussed in the second part of this article at examples of areas having a different shapes.

12

Robustness study of the road profile estimation technique under uncertainty

Ben Jdidia Anoire, Ben Hassen Dorra, Hentati Taissir, Abbes Slim, Haddar Mohamed

Journal of Theoretical and Applied Mechanics

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2022

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Vol. 60 nr 3

521--533

EN

This paper studies profile estimation a road. The prediction has been achieved using the Independent Component Analysis Method (ICA). The vehicle dynamic responses were cal- culated for different road profiles which were defined using an ISO norm. The robustness of this method was proven by implementing the stochastic Monte Carlo (MC) technique in the presence of inevitable uncertainty parameters simultaneously associated with the vehicle mass, spring stiffness and damping for different vehicle speeds and wind values. Convergence was assessed when comparing real profiles to simulated ones. The obtained results prove the efficiency of the ICA in estimating the profile variabilities under uncertainties.

13

Modeling and Parameter Estimation of Radar Sea-Clutter with Trimodal Gamma Population

Terki Zakia, Mezache Amar, Chebbara Fouad

Journal of Telecommunications and Information Technology

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2022

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nr 2

82--90

EN

Real radar data often consist of a mixture of Gaussian and non-Gaussian clutter. Such a situation creates one or more inflexion points in the curve of the empirical cumulative distributed function (CDF). In order to obtain an accurate fit with sea reverberation data, we propose, in this paper, a trimodal gamma disturbance model and two parameter estimators. The non-linear least-squares (NLS) fit approach is used to avoid computational issues associated with the maximum likelihood estimator (MLE) and moments-based estimator for parameters of the mixture model. For this purpose, a combination of moment fit and complementary CDF (CCDF) NLS fit methods is proposed. The simplex minimization algorithm is used to simultaneously obtain all parameters of the model. In the case of a single gamma probability density function, a zlog(z) method is derived. Firstly, simulated life tests based on a gamma population with different shape parameter values are worked out. Then, numerical illustrations show that both MLE and zlog(z) methods produce closer results. The proposed trimodal gamma distribution with moments NLS fit and CCDF NLS fit estimators is validated to be in qualitative agreement with different cell resolutions of the available IPIX database.

14

Estimation of the angular position of a two–wheeled balancing robot using a real IMU with selected filters

Laddach Krzysztof, Łangowski Rafał, Zubowicz Tomasz

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2022

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Vol. 70, nr 2

art. no. e140518

EN

A low–cost measurement system using filtering of measurements for two–wheeled balancing robot stabilisation purposes has been addressed in this paper. In particular, a measurement system based on gyroscope, accelerometer, and encoder has been considered. The measurements have been corrected for deterministic disturbances and then filtered with Kalman, a–b type, and complementary filters. A quantitative assessment of selected filters has been given. As a result, the complete structure of a measurement system has been obtained. The performance of the proposed measurement system has been validated experimentally by using a dedicated research rig.

15

High-resolution Direction of Arrival Estimation Method Based on Sparse Arrays with Minimum Number of Elements

Mohammed Jafar Ramadhan

Journal of Telecommunications and Information Technology

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2021

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nr 1

8--14

EN

Regular fully filled antenna arrays have been widely used in direction of arrival (DOA) estimation. However, practical implementation of these arrays is rather complex and their resolutions are limited to the beamwidth of the array pattern. Therefore, higher resolution and simpler methods are desirable. In this paper, the compressed sensing method is first applied to an initial fully filled array to randomly select the most prominent and effective elements which are used to form the sparse array. To keep the dimension of the sparse array equal to that of the fully filled array, the first and the last elements were excluded from the sparseness process. In addition, some constraints on the sparse spectrum are applied to increase estimation accuracy. The optimization problem is then solved iteratively using the iterative reweighted l1 norm. Finally, a simple searching algorithm is used to detect peaks in the spectrum solution that correspond to the directions of the arriving signals. Compared with the existing scanned beam methods, such as the minimum variance distortionless response (MVDR) technique, and with subspace approaches, such as multiple signal classification (MUSIC) and ESPIRT algorithms, the proposed sparse array method offers better performance even with a lower number of array elements and in severely noisy environments. Effectiveness of the proposed sparse array method is verified via computer simulations.

16

An interval Kalman filter enhanced by lowering the covariance matrix upper bound

Tran Tuan Anh, Jauberthie Carine, Trave-Massuyés Louise, Lu Quoc Hung

International Journal of Applied Mathematics and Computer Science

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2021

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Vol. 31, no. 2

259--269

EN

This paper proposes a variance upper bound based interval Kalman filter that enhances the interval Kalman filter based on the same principle proposed by Tran et al. (2017) for uncertain discrete time linear models. The systems under consideration are subject to bounded parameter uncertainties not only in the state and observation matrices, but also in the covariance matrices of the Gaussian noises. By using the spectral decomposition of a symmetric matrix and by optimizing the gain matrix of the proposed filter, we lower the minimal upper bound on the state estimation error covariance for all admissible uncertainties. This paper contributes with an improved algorithm that provides a less conservative error covariance upper bound than the approach proposed by Tran et al. (2017). The state estimates are determined using interval analysis in order to enclose the set of all possible solutions of the classical Kalman filter consistent with the uncertainties.

17

Low altitude control for quadcopter using visual feedback

Urbański Konrad

Archives of Electrical Engineering

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2021

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Vol. 70, nr 4

845--858

EN

The paper presents the results of simulations and experiments in the field of control of the low damping and time delay oscillating system. This system includes a quadcopter hovering at a very low altitude, and the altitude is controlled. The time delay is introduced mainly by the remote control device. In order to handle the quadcopter at low altitudes, a proportional-integral controller with a negative proportional coefficient is used. Such an approach can provide good results in the case of an oscillating, low damped system. This method of steering, which uses a typical radio control transmitter, can be used on any commercially available leisure drone. Feedback is provided by a camera and algorithms of computer vision. The presented results were obtained experimentally using free flight–without a harness. Different types of controllers are used to control horizontal shift and altitude.

18

The algorithm of adaptive determination of amplification of the PD filter estimating object state on the basis of signal measurable on-line

Kwater Tadeusz, Hawro Przemysław, Bartman Jacek, Mazur Damian

Archives of Control Sciences

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2021

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Vol. 31, No. 1

129--143

EN

The article presents the algorithm that enables adaptive determination of the amplification coefficient in the filter equation provided by Kalman. The method makes use of an estimation error, which was defined for this purpose, and its derivative to determine the direction of correction changes of the gain vector. This eliminates the necessity to solve Riccati equation, which causes reduction of the method computational complexity. The experimental studies carried out using the proposed approach relate to the estimation of state coordinates describing river pollution using the BOD (biochemical oxygen demand) and DO (dissolved oxygen) indicators).The acquired results indicate that the suggested method does better estimations than the Kalman filter. Two indicators were used to measure the quality of estimates: the Root Mean Squared Error (RMSE) and the Mean Percentage Error (MPE).

19

Maximum simulated likelihood: don't stop believin'?

Schrey Christopher

Annals of Computer Science and Information Systems

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2021

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Vol. 26

175--180

EN

Unobserved heterogeneity may complicate model estimation in econometrics. To integrate out the effect of unobserved heterogeneity via maximum simulated likelihood (MSL) estimation, assumptions regarding the underlying distribution need to be made. Researchers seldomly discuss these assumptions. This raises the question, to what extent estimation results in the MSL-context are robust to potential distributional mismatch. This work-in-progress derives the research question from the literature. A simulation study is conducted that underpins the relevance of this matter, where results imply that mismatch may introduce significant bias. Intended future work to properly address and answer this question is defined and discussed.

20

Estimation of hydromechanical parameters of limb lymphedematous tissue with the use of chamber tests

Kaczmarek Mariusz, Nowak Joanna, Olszewski Waldemar, Zaleska Marzanna

Acta of Bioengineering and Biomechanics

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2021

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Vol. 23, no. 1

149--161

EN

Purpose: In this paper, in vivo methods of estimation of the shear modulus and hydraulic permeability of subcutaneous tissue of lower limb are presented. Methods: The experimental technique is based on single- or two-chamber inflation-deflation tests in which temporal changes in limb circumference under the test chamber for cyclic loading are registered. Simplified models for fast undrained deformation and slow creep of oedematous tissue with squeezing out interstitial liquid were considered. Finite element simulations of the chamber test within a finite deformation poroelastic model were elaborated. Results: Formulas necessary to estimate the shear modulus and permeability of subcutaneous tissue were derived and then tested or calibrated using the results of poroelastic simulations. An example of application of the derived formulas for clinical data obtained from the chamber test was discussed. Conclusions: A simple in vivo methods of estimation of the hydromechanical properties of lymphedematous tissue (shear modulus and permeability) were proposed. The strengths and weaknesses of the proposed methodology were discussed.