Wyniki wyszukiwania - BazTech

1

Realizacja sprzętowa algorytmu sterującego systemem oświetleniowym wspomagającym rytm dobowy

Ptak Przemysław, Burnicki Michał, Górecki Krzysztof

Przegląd Elektrotechniczny

|

2026

|

R. 102, nr 5

234--239

PL

W pracy przedstawiono wyniki badań eksperymentalnych dotyczących opracowanego układu wspomagającego rytm dobowy człowieka za pomocą źródła światła LED (Light Emitting Diode). Opisano podstawowe elementy opracowanego układu oraz ich parametry eksploatacyjne, a także krótko scharakteryzowano wykonywane przez nie funkcje. Opisano układ pomiarowy, który pozwolił na rejestrację parametrów eksploatacyjnych zaproponowanego układu. Przedstawiono również algorytm sterujący opracowanym urządzeniem. Wyniki badań eksperymentalnych dowodzą, że opracowany układ sterujący czterokanałowym źródłem światła LED spełnia zadanie regulacji rytmu dobowego człowieka.

EN

This paper presents the results of an experimental study of a developed system supporting the human diurnal rhythm with a Light Emitting Diode (LED) light source. The basic elements of the developed system and their operating parameters are described, and the functions they perform are briefly characterised. The measurement system that allowed recording the performance parameters of the proposed system is described. The control algorithm of the developed device is also presented. Experimental results prove that the developed system controlling a four-channel LED light source fulfils the task of regulating the human diurnal rhythm.

2

Design and Performance Evaluation of Thrust Stand for Electric UAV Propulsion Using Brushless DC Motor

Irmawan Erwhin, Prasetiyo Erwan Eko, Ommar Syafutrah Bin, Bukhori M. Luqman, Marausna Gaguk, Pratama Henriana Helda

Przegląd Elektrotechniczny

|

2026

|

R. 102, nr 2

111--117

EN

Technological advancements have enabled flying robots to assist with both routine and hazardous tasks. This study focuses on the design and testing of a thrust meter to measure thrust and electric current. The device was designed in Fusion and consists of three main parts: a base, an electric stand, and a motor mount. It integrates an Arduino Uno, a 16x2 LCD, an HX711 sensor, a DC wattmeter, and a digital servo tester. Testing was carried out using a 1400KV A2212 BLDC motor, a 9x4.5 propeller, and a 5 kg load cell. Results show the thrust meter provides linear and stable measurements of thrust relative to PWM and RPM values, making it suitable for evaluating the performance of light UAV propulsion systems.

PL

ostęp technologiczny umożliwił wykorzystanie robotów latających do wykonywania zarówno rutynowych, jak i niebezpiecznych zadań. Celem niniejszego badania było zaprojektowanie i przetestowanie miernika ciągu do pomiaru siły ciągu oraz prądu elektrycznego. Urządzenie zostało zaprojektowane w programie Fusion i składa się z trzech głównych elementów: podstawy, stojaka elektrycznego i uchwytu silnika. W jego skład wchodzą: Arduino Uno, wyświetlacz LCD 16x2, czujnik HX711, watomierz DC oraz cyfrowy tester serwomechanizmów. Testy przeprowadzono z użyciem silnika BLDC A2212 1400KV, śmigła 9x4.5 oraz czujnika tensometrycznego o nośności 5 kg. Wyniki pokazują, że miernik ciągu zapewnia stabilne i liniowe pomiary w zależności od wartości PWM i RPM, co czyni go odpowiednim narzędziem do oceny wydajności napędów lekkich dronów.

3

Preliminary results of laboratory tests of an innovative system for measuring light pollution

Szczepańczyk Andrzej, Śmigielski Grzegorz, Nowak Joanna, Dalecki Mikołaj

Materiały Budowlane

|

2026

|

nr 5

15--24

EN

The subject of this article is to evaluate the repeatability and usability of a proprietary light pollution measurement system that enables both stationary measurements and those using unmanned aerial vehicles (UAVs). Results from the preliminary laboratory tests demonstrated correlation with reference measurements obtained from a certified commercial device. Additionally, dedicated software enables real-time analysis of results and the entire system is intuitive to use, even by unskilled users.

PL

W artykule zaprezentowano ocenę powtarzalności i użyteczności autorskiego systemu do pomiaru zanieczyszczenia światłem, który umożliwia zarówno prowadzenie pomiarów stacjonarnych, jak również z wykorzystaniem bezzałogowych statków powietrznych (BSP). Wstępne wyniki badań laboratoryjnych wykazały korelację z referencyjnymi pomiarami, uzyskanymi z certyfikowanego miernika komercyjnego. Dodatkowo oprogramowanie umożliwia analizę wyników w czasie rzeczywistym, a cały układ jest intuicyjny do obsługi nawet przez niewykwalifikowanego użytkownika.

4

Visual comfort and light transmission control using window with polymer dispersed liquid crystal layer in the textile industry to ensure occupational safety

Frydrysiak Michał

Advances in Science and Technology. Research Journal

|

2026

|

Vol. 20, no. 3

261--275

EN

Adequate workplace lighting is crucial for employee well-being, productivity and energy efficiency. Yet many industrial settings, such as textile factories, have inadequate, non-adaptive lighting. In the presented article, author focused on the problem of inadequate lighting conditions in the workplace. Driven by the need for ergonomic workspaces and sustainable energy practices, this research uses advanced materials PDLC science to address these challenges. It proposes solution in the form of an automatic system for regulating the lighting intensity by automatic regulation of light transmittance through Smart Window including a PDLC film.. The control of light transmittance into the knitting factory hall is performed by (control of the voltage of the active film layer) which is an integral part of the entire window surface. A smart window will reduce the overall transmission of solar energy, which will help avoid overheating. Total solar factor is the percentage of solar energy that actually penetrates a room through blinds and windows. Smart Window will also provide visual comfort by optimizing the amount of light reaching the surface near the window and avoiding glare and inconvenience caused by direct sunlight. Visible light transmittance determines the total percentage of daylight that is transmitted into the room through the window with a wavelength from 380 to 780 nm (visible spectrum). The main results demonstrate a strong correlation between the applied voltage and the film's light transmittance, enabling precise control over the Visible Light Transmittance (VLT). The implemented control model successfully maintained optimal illuminance levels, reducing glare and preventing solar overheating by dynamically adjusting the window's opacity. From a methodological point of view, one of the most important issues in designing a lighting intensity control system is choosing the type of sensor and its location in the production hall. This can significantly affect control efficiency. This topic is discussed in this article, which briefly covers good industrial design practices. This approach to lighting requirements is supported by legal requirements, as well as an ergonomic approach to the design of workplaces. Implementing lighting control systems in textile factories is a strategic step towards digital transformation and sustainability which is in line with Responsible Consumption and Production strategy.

5

An improved algorithm for polarisation plane rotation angle measurement

Kozieł Grzegorz

Advances in Science and Technology. Research Journal

|

2026

|

Vol. 20, no. 1

74--88

EN

Sensors using tilted fibre Bragg gratings (TFBG) are now widely used and intensively developed due to their high precision, interference immunity, small size and low price. One of the parameters that can be measured with them is the angle of light polarisation plane rotation (LPPR) propagating in the optical fibre. Existing TFBG sensors are based on measuring the power of light at a selected wavelength, which results in a limited measurement range and low precision. Other methods are based on advanced algorithms that process a selected range of the TFBG spectrum using a wavelet (DWT) or Fast Fourier Transform (FFT). However, achieving high precision over the entire measurement range is impossible due to the similar FFT and DWT coefficient variation. In the present study, it was identified that a cascaded connection of two TFBGs, rotated relative to each other, allows for obtaining the variability function of the cladding mode minima (MMCl) shifted in relation to one another as a function of the LPPR angle. This enables direct utilisation of the minima values in the algorithm calculating the LPRR angle based on the light spectrum. Furthermore, the obtained MMCl functions exhibit a significantly lower level of interference than the previously employed FFT coefficient variability waveforms. These phenomena were used to develop a method for calculating the measurement result from the measured light spectra. Based on the cladding mode minima values measured for angles 0°, 2°, 4°,…, 180°, a calibration was conducted. An algorithm was developed to select the MMCl functions that will be used to calculate the measured rotation angle. The developed solution allows measuring the light polarisation plane rotation angle with equal precision in the range of 0°-180°. Applying the proposed method has improved the measurement's stability. Compared to existing solutions, MAE was improved by 2.6% and MSE by 66%.

6

Selected methods for measuring market and sector globalization and enterprise internationalization

Kuraś Piotr

Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska

|

2025

|

z. 224

255--281

EN

Purpose: This paper aims to identify and describe the methods for measuring the level of globalization of national economies and sectors, as well as the level of internationalization of the business activities of manufacturing enterprises. Design/methodology/approach: The paper is of a theoretical nature. The literature review served as the starting point, allowing for the assessment of the current state of knowledge on measuring globalization and internationalization. This allowed for the formulation of the research problem. Findings: There is no single, universally recognized and accepted way to measure globalization, either at the level of economies or sectors. Globalization is a complex, complicated and multidimensional process. Researchers propose qualitative approaches, while quantitative measurement concepts are also known and developed. The level of internationalization is most often studied through the prism of either geographical scope or the degree of foreign involvement in particular activities. Research limitations and implications: The research systematizes and synthesizes scientific knowledge in measuring the processes of globalization and internationalization. The main limitation of this research is that, due to the complexity of the studied phenomena and the nature of this article, it is not possible to provide a comprehensive analysis or exhaustive description. The paper presents only the most useful attempts to formally describe these, after all, qualitative economic phenomena. Practical and social implications: The article is addressed mainly to the scientific community. The methods presented here can be a starting point for discovering new relationships and interdependencies. For example, the relationship between the level of internationalization and corporate performance can be studied. The results of such research can help managers make decisions about the scope and intensity of a company's foreign operations. Originality and value: The originality of the research lies in the attempt to systematize and synthesize the scattered scientific studies on measuring the internationalization of enterprises and the globalization of sectors and economies. The conclusions of this paper contribute to a better understanding of these phenomena.

7

Technika testowania w latach 60. XX w. (cz.1)

Branczewski Mirosław

Wiadomości Elektrotechniczne

|

2025

|

R. 93, nr 6

35--39

PL

W Niemczech w 1955 r. założono grupę roboczą VDE 0435, zajmującą się zabezpieczeniami. W 1962 r. opublikowano dokument „Wytyczne dotyczące przekaźników w systemach wysokiego napięcia („Regeln für elektrische Relais in Starkstromanlagen”, rys. 1). Wytyczne dotyczyły działania i eksploatacji zabezpieczeń oraz pomiarów. W 1960 r. założono TC 41 w IEC, która jest odpowiednim międzynarodowym organem normalizacyjnym („Zabezpieczenia”). Zaktualizowana wersja niemieckich wytycznych została opublikowana jako VDE 0435/9.62.

8

Some aspects of research on an Arduino Uno-based CNC plotter machine

Nechval Konstantin, Reiskarts Vladimirs, Chatys Rafał

Science, Technology and Innovation

|

2025

|

Vol. 23, no. 4

20--26

EN

Due to their simple kinematics, accessible components, and low operating costs, CNC plotters are among the most affordable and easy-to-use CNC devices. This makes them practically indispensable in universities and laboratories, where they are primarily used for educational purposes, such as learning the basics of CAD/CAM, interpreting control programs, and understanding the fundamental principles of servo drives and feedback systems. This article discusses both the advantages and the limitations of CNC plotters and laser systems. A method for improving pen control throughout the entire operation process is proposed, addressing a limitation commonly observed in CNC machines and 3D printers. Typically, control is performed using end sensors only at the initial stage of processing and calibration. During subsequent operation, such systems function in an open-loop or weakly monitored mode.

9

Technologie kwantowe w geodezji i geoinformatyce

Bednarek Stanisław

Przegląd Geodezyjny

|

2025

|

R. 97, nr 10

18--21

PL

W ostatnich latach pojawia się coraz więcej zastosowań zjawisk kwantowych w nowoczesnych technologiach i urządzeniach spotykanych w codziennym życiu. Taki proces zachodzi również w geodezji i geoinformatyce. Dzięki temu jest możliwe m.in. stworzenie dokładniejszych wzorców jednostek, wielokrotne zwiększenie czułości instrumentów pomiarowych i wzrost szybkości wykonywania obliczeń. Zastosowanie praw opisujących zjawiska kwantowe pozwala też wyznaczyć granice możliwości pomiarowych i eliminacji zakłóceń. Artykuł dotyczy wymienionych problemów.

EN

In recent years, there has been an increasing number of applications of quantum phenomena in modern technologies and devices encountered in everyday life. This process is also taking place in geodesy and geoinformatics. This makes it possible, among other things, to create more accurate unit standards, significantly increase the sensitivity of measuring instruments, and increase the speed of calculations. The application of the laws describing of quantum phenomena also allows us to determine the limits of measurement precision and eliminate disturbances. These enumerated problems are presented in this article.

10

Wybrane problemy pomiarów rezystywności cieplnej gruntów

Wesołowski Marcin, Czerwiński Michał

Przegląd Elektrotechniczny

|

2025

|

R. 101, nr 10

27--32

PL

Badania przewodności cieplnej właściwej (lub rezystywności termicznej) gruntów są istotne, z punktu widzenia potencjalnych możliwości odprowadzania energii cieplnej z aktywnych elementów generacyjnych znajdujących się, najczęściej, bezpośrednio w ziemi. Zazwyczaj badania wykonywane są przy wykorzystaniu metody dynamicznej, opisanej w normie D5334- 14 ASTM. Procedura ta charakteryzuje się jednak dość wieloma ograniczeniami. W niniejszej pracy zaproponowano precyzyjną metodę wyznaczania przewodności cieplnej właściwej gruntów z wykorzystaniem aparatu rurowego. W szczególności zwrócono uwagę na zagadnienia regulacji, pozwalające na wytworzenie pożądanego jednowymiarowego promieniowego rozkładu temperatury.

EN

Studies of the specific thermal conductivity (or thermal resistivity) of soils are important from the perspective of the potential ability to dissipate heat from active generating elements, which are most often located directly in the ground. Typically, such studies are carried out using the dynamic method described in ASTM standard D5334-14. However, this procedure is characterized by a number of limitations. In this work, a precise method for determining the specific thermal conductivity of soils using a tube apparatus is proposed. Particular attention is given to control issues that enable the creation of the desired one-dimensional radial temperature distribution.

11

Wpływ częstotliwości na rozkład indukcji pola magnetycznego i temperatury dla cewki płaskiej

Detka Kalina, Downar-Zapolski Michał, Górecki Krzysztof

Przegląd Elektrotechniczny

|

2025

|

R. 101, nr 10

121--126

PL

W pracy przedstawiono wyniki badań eksperymentalnych ilustrujących wpływ częstotliwości na rozkład pola magnetycznego i temperatury w cewce płaskiej. W czasie pomiarów cewka była zasilana prądem sinusoidalnym. Pole magnetyczne zmierzono zarówno na powierzchni badanej cewki, jak i nad nią, natomiast temperaturę zmierzono tylko na powierzchni uzwojenia. Przedyskutowano uzyskane wyniki pomiarów i wskazano warunki pracy cewki, przy których uzyskano największą nierównomierność zmierzonych rozkładów.

EN

The paper presents the results of experimental studies illustrating the effect of frequency on the distribution of the magnetic field and temperature in a flat coil. During the measurements, the coil was supplied with a sinusoidal current. The magnetic field was measured both on the surface of the tested coil and above it, whereas the temperature was measured only on the surface of the winding. The obtained measurement results were discussed and the coil operating conditions at which the greatest non-uniformity of the measured distributions was obtained were indicated.

12

Testing the SDC memristors in three phase systems

Garda Bartłomiej, Bednarz Karol

Przegląd Elektrotechniczny

|

2025

|

R. 101, nr 2

52--55

EN

The objective outlined in the paper is to conduct reliable measurement tests on memristor behavior in three-phase systems. Memristors, acting as nonlinear elements, exhibit intriguing phenomena within such systems. Various configurations, including Delta and Wye connections with three and four wires, have been tested. The collected data has been analyzed and presented, with additional frequency analysis using FFT and assessment of total harmonic distortion factors. The acquired data has been modelled using the MMS memristor model and compared with the actual data.

PL

W artykule przedstawiono wyniki testów pomiarowych opisujących zachowania memrystorów w systemach trójfazowych. Memrystory, jako nieliniowe elementy, wykazują˛ intrygujące zjawiska w takich systemach. Przetestowano różne konfiguracje, w tym połączenia w trójkąt, w gwiazdę z trzema i czterema przewodami. Zebrane dane zostały przeanalizowane i przedstawione. Dokonano analizy częstotliwościowej FFT oraz wyznaczono współczynniki całkowitego zniekształcenia harmonicznego THD. Następnie uzyskane wyniki pomiarowe zostały zamodelowane z wykorzystaniem modelu memrystora MMS i porównane z danymi rzeczywistymi.

13

Modeling and measurement of the propagation of carrier currents in lines on MV/LV transformers equipped with its power lines

Sekki Daoud, Azizi Hakim, Chebout Mohammed, Kihal Mohammed Charif, Kihal Marouane

Przegląd Elektrotechniczny

|

2025

|

R. 101, nr 8

63--72

EN

In this paper, we study the propagation of the on ‑line carrier currents (PLC) on the domestic electrical network con taining the power lines and the medium/base voltage transformer (MV/LV). To achieve this, we propose an efficient and precise modeling through the power transformer. Electrical energy is a physical quantity that can be measured in an unambiguously way, which is not the case for voltage and current. The bond graph analysis (integrated under SIMULINK (Matlab), based on energy and its conservation, appears to be the most suitable method for modeling low ‑level signal transmission. To demonstrate this advantage, we treat an application on a power transformer. The results obtained through numerical simulation are com pared and validated by the measurement. Good agreements are found between this approach and measurement.

PL

W tym artykule badano propagację prądów nośnych on ‑line (PLC) w domowej sieci elektrycznej zawierającej linie energetyczne i transformator napięcia średniego/podstawowego (MV/LV). Aby to osiągnąć, proponuje się wydajne i precyzyjne modelowanie za pomocą transformatora mocy. Energia elektryczna jest wielkością fizyczną, którą można zmierzyć w sposób jednoznaczny, co nie jest prawdą w przypadku napięcia i prądu. Analiza wykresu wiązań (zintegrowana w ramach SIMULINK (Matlab), oparta na energii i jej zachowaniu, wydaje się być najbardziej odpowiednią metodą modelowania transmisji sygnału niskiego poziomu. Aby zademonstrować tę zaletę, autorzy rozpatrują aplikację w transformatorze mocy. Wyniki uzyskane za pomocą symulacji numerycznej są porównywane i weryfikowane za pomocą pomiaru. Znaleziono dobrą zgodność między tym podejściem a pomiarem.

14

Enhancing Non-Intrusive Load Monitoring comparative analysis of feature-based and impedance-based approaches

Krawczyk Sławomir, Wiszniewski Przemysław, Makowiecki Karol, Sitek Piotr

Przegląd Elektrotechniczny

|

2025

|

R. 101, nr 12

210--216

EN

Non-Intrusive Load Monitoring (NILM) relies on the extraction of meaningful features from electrical signals to effectively disaggregate power consumption. Traditional NILM methods often focus on low-frequency power features, while recent advancements explore more sophisticated signal processing techniques. This study investigates two feature extraction approaches based on sinusoidal current and voltage waveforms. First, the impact of using only apparent power and phase shift angle is analyzed, followed by an evaluation of harmonic components alone. The results indicate that the best performance is achieved by combining these features into a single method, which constitutes the first approach. The second approach focuses on computing the impedance of the first forty harmonics. Both methods are evaluated using the KNeighborsClassifier from the scikit-learn library, with prediction performance measured using the "score" metric. The findings provide insights into the effectiveness of these feature sets and their potential advantages over existing NILM techniques.

PL

Nieinwazyjna identyfikacja odbiorników energii elektrycznej (Non-Intrusive Load Monitoring -NILM)to metoda która, polega na ekstrakcji istotnych cech sygnałów elektrycznych w celu skutecznej dekompozycji zużycia energii. Tradycyjne metody NILM zazwyczaj opierają się na niskoczęstotliwościowych cechach mocy, natomiast nowsze podejścia wykorzystują bardziej zaawansowane techniki przetwarzania sygnałów. W niniejszej pracy przeanalizowano dwa podejścia do ekstrakcji cech opartych na sinusoidalnych przebiegach prądu i napięcia. Najpierw oceniono wpływ wykorzystania wyłącznie mocy pozornej i kąta fazowego, a następnie przeanalizowano skuteczność samych składowych harmonicznych. Układ eksperymentalny obejmował zarówno liniowe, jak i nieliniowe odbiorniki elektryczne, aby zagwarantować możliwość obsługi szerokiego zakresu charakterystyk obciążenia oraz realistycznych warunków pracy. Wyniki wskazują, że najwyższą skuteczność zapewnia połączenie obu zestawów cech w jedną metodę, co odpowiada pierwszemu analizowanemu podejściu. Uzyskane rezultaty dostarczają istotnych informacji na temat efektywności tych cech oraz ich potencjalnych przewag nad istniejącymi technikami NILM.

15

Multi-Symptom Diagnostic Investigation of the Working Process of a Marine Diesel Engine: Case Study. Part 2 Simulation Diagnostics

Korczewski Zbigniew, Varbanets Roman, Minchev Dmytro, Rudnicki Jacek

Polish Maritime Research

|

2025

|

nr 4

87--96

EN

This second part of our manuscript deals with the diagnostic capabilities of the Blitz-PRO utility computer program. These capabilities form the basis of the Weichai WP4 engine’s digital twin, in terms of multi-symptom identification of selected states of the engine’s fed system and valve train system. These states include the use of non-standard fuel, the wear of precision pairs of the high-pressure fuel pump, and mismatched camshaft positioning during engine assembly after maintenance. The basic assumptions of the mathematical model of the diesel engine used in Blitz-PRO are outlined here, and numerical experiments are conducted on the model to simulate the behaviour of the Weichai WP4 engine after the introduction of the considered states. Based on the results of numerical simulations of the working process, a relational model is proposed, which forms the basis for diagnostic reasoning. A comparative analysis of the changes in the diagnostic parameters of the relational model and the resulting syndromes enables early detection of similar states of fuel-fed systems for similar engine types.

16

Multi-Symptom Diagnostic Investigation of the Working Process of a Marine Diesel Engine: Case Study. Part 1. Measurement Diagnostics

Korczewski Zbigniew, Rudnicki Jacek, Varbanets Roman, Minchev Dmytro

Polish Maritime Research

|

2025

|

nr 2

50--61

EN

The manuscript discusses the issue of diagnostic informativeness of measurement signals recorded during electronic indication of marine engine cylinders. It was noted that the “ fault-syndrome” relations of the diagnostic model determined on this basis are usually ambiguous, which forces the need to search for additional symptoms that ultimately confirm the diagnosis. A method of multi-symptom recognition of disturbances in the engine’s working process is presented by means of measurement experiments carried out on a real object and numerical experiments, with the appropriate usage of its “digital twin”. In the first part of the manuscript, the possibilities of carrying out diagnostic conclusions about the technical health of the valve timing system of a single-cylinder, naturally aspirated Farymann Diesel type D10 marine engine were examined based on simultaneous measurements of its standard operating parameters, exhaust gas composition, in-cylinder pressure and acoustic vibrations generated from the cylinder head by the working fuel injector and cylinder valves. Selected metrological issues of conductiong such measurements. As a result of the engine tests, extensive wear of the camshaft cams was identified, which resulted in premature closing of the exhaust valve and delayed opening of the intake valve. The shifts in the valve timing were so significant that there was practically no valves openning overlap in the cylinder flushing phase. To finally verify the primary formulated diagnosis, dynamic measurements of the engine valve timing were conducted using external inductive sensors, and then the camshaft was dismantled from the engine and subjected to direct optical examinations.

17

Pomiarowe wyznaczanie przestrzennego rozkładu indukcji magnetycznej

Jarek Tomasz, Decner Adam, Barański Marcin, Pindych Filip

Napędy i Sterowanie

|

2025

|

R. 27, nr 10

62--65

PL

W artykule przedstawiono założenia projektowe przyrządu przeznaczonego do precyzyjnego wyznaczania rozkładu przestrzennego indukcji magnetycznej. Opisano zasadę działania urządzenia, opartą na wykorzystaniu precyzyjnego czujnika Halla umożliwiającego pomiar indukcji magnetycznej w 3 osiach. Przedstawiono również konstrukcję mechaniczną i elektroniczną prototypowego urządzenia, w tym system pozycjonowania w przestrzeni pomiarowej.

EN

The article presents the design assumptions of a device intended for the precise determination of the spatial distribution of magnetic flux density. The operating principle of the device is described, based on the use of a precise Hall sensor enabling the measurement of magnetic flux density along three axes. The mechanical and electronic construction of the prototype device is also presented, including the positioning system within the measurement space.

18

System for measuring electric parameters of thermoelectric cell battery of a sectional module with thermogenerators

Neska Mirosław, Opara Tadeusz

Metrology and Measurement Systems

|

2025

|

Vol. 32, nr 1

art. no. 3, 1--18

EN

One way to manage low-temperature heat is to convert it directly into DC electricity using thermocells. By placing a single thermoelectric generator or a battery of thermoelectric cells between two heat exchangers, one side with a higher temperature medium and the other with a lower temperature medium, a temperature difference is created between the covers of the thermoelectric elements, which causes heat transfer and the generation of electricity. The module with thermogenerators and exchangers (MTEG) discussed in the article is equipped with a developed measurement system. This system is used to determine the electric current of twenty, serially-connected thermoelectric generators and to measure the electric voltage across the load resistance of the thermoelectric circuit. The publication presents subcircuits for measuring the internal resistance of two thermogenerators placed symmetrically in individual sections of the MTEG module. According to the developed test method, the measurement system was verified in cyclic tests with varying thermodynamic forcing. The accuracies of the test bench electric parameter measurement paths were estimated, yielding expanded uncertainties of ±0.012 W in the measurement of generated electric power and ±0.0008 Ω and ±0.0009 Ω in the resistance of the internal thermogenerators, respectively. Repeatability (EV) was verified and the “capability” of the developed measurement system to function correctly was confirmed.

19

Frequency stability of software-defined radios - part II. Modeling for simulation studies

Bednarz Kacper, Wojtuń Jarosław, Kelner Jan M., Ziółkowski Cezary, Leśnik Czesław

Metrology and Measurement Systems

|

2025

|

Vol. 32, nr 4

art. no. 11, 1--16

EN

In the first part of this paper, we measured the frequency stability of widely available software-defined radio (SDR) platforms. The second part focuses on the problem of modeling the frequency instability of these devices, which is necessary in the process of designing new applications using simulation studies. This modeling is based on the measurement results obtained in the first part. For this purpose, the nature of changes in the instantaneous frequency of the received signal as a function of time is analysed, separating them into two parts, i.e., a slow-changing trend and a fast-changing random component. A method of estimating the trend and fitting the normal distribution to fast frequency fluctuations is proposed to model the instantaneous frequency changes for several popular SDRs (including ADALM-PLUTO, B200mini, bladeRF, and USRP). The assumption about normal distribution for fast fluctuations is verified using the chi-square test. The models obtained enable the generation of signals in simulation studies that realistically represent the frequency variability observed in the measurements. The proposed approach enables simulation tests on SDR-based solutions, considering the impact of frequency instability without conducting long-standing or complex laboratory experiments.

20

Frequency stability of software-defined radios - part I. Measurements

Bednarz Kacper, Wojtuń Jarosław, Kelner Jan M., Ziółkowski Cezary, Leśnik Czesław

Metrology and Measurement Systems

|

2025

|

Vol. 32, nr 3

art. no. 15, 1--18

EN

The popularity and high efficiency of the software-defined radio (SDR) architecture led to its export to other areas of technology, 𝑒.𝑔., software-defined networks, vehicles, infrastructure, etc. These devices, as commercials off-the-shelfs (COTS), are the basis for numerous implementations and prototyping of new solutions. SDR allows for easy adoption of existing or development and testing of new communication standards, protocols, etc., also thanks to the support of open and free applications. SDR frequency stability is important in numerous applications, especially in techniques based on frequency measurement. This paper presents the methodology for frequency stability measurements for several popular COTS SDR platforms. Measurement was conducted in two variants, with and without an external rubidium frequency standard (RFS). We generally analyse two groups of frequency stability metrics, 𝑖.𝑒., the fundamental parameters and the Allan deviation that provide a comparison of measurement and manufacturer datasheet. These parameters are analysed as a function of time depending on the selected measurement intervals. We determine the distribution of the parameters tested, which is the basis for assessing and classifying SDRs. The results obtained can serve as a basis for modelling the SDR instability phenomenon in future simulation studies, including our own planned work as well as broader research conducted by the scientific community.