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Tytuł:
Phase Shifted Pulse Height Modulated Motor Control for Multiply Actuated Joints to Optimize Operating Characteristics
Autorzy:
Siedel, T.
Bethge, S.
Hild, M.
Powiązania:
https://bibliotekanauki.pl/articles/385220.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
multiple actuators
model-free
frictrion compensation
pulse modulation
Opis:
In this article, we propose two model free control schemes that are based on pulse height modulation using low frequencies with the goal to compensate normal friction effects in drive trains that negatively influence the performance of e.g. a standard PID controller. The first control scheme uses pulse height modulation to especially compensate stick slip effects but increases vibration and noise in the drive train. To reduce such side effects a modified phase shifed pulse height control scheme based on multiple actuated joints is introduced. Both control schemes are compared with a standard linear controller as reference and evaluated by using six quality criteria.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2016, 10, 2; 15-24
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Broadband power electronics controlled current source with analogue control section and output stage based on GaN transistors
Autorzy:
Gwóźdź, M.
Powiązania:
https://bibliotekanauki.pl/articles/377021.pdf
Data publikacji:
2017
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
converter control
GaN transistor
interleaved technique
pulse modulation
Opis:
The paper presents the conception of the power electronics controlled current source based on the sigma–delta modulator (SDM). Due to very high frequency of the SDM output bit stream, in the power stage of inverter the gallium-nitride (GaN) transistors are used. In these circumstances even efficient DSPs are unable, due to limitation of its pass–band of the control path, to obtain right parameters of the output current regulator. So, the regulator is done in the fully analogue manner. As result of these the value of distortions of the inverter output current is much lower, compared to the typical, PWM based, solutions. This benefit is not paid significantly by increase in the system complexity. In work the converter operation basics and results of its simulation model studies are presented.
Źródło:
Poznan University of Technology Academic Journals. Electrical Engineering; 2017, 91; 55-61
1897-0737
Pojawia się w:
Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Trellis Coded 4-ary PAM using Distance-Preserving Mapping
Autorzy:
Shongwe, T.
Powiązania:
https://bibliotekanauki.pl/articles/226278.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
distance-preserving mappings
hamming distance
euclidean distance
pulse amplitude modulation
Opis:
A trellis coded 4-ary Pulse Amplitude Modulation (4-PAM) is presented, where the encoding algorithm is derived from Distance Preserving Mapping (DPM) algorithm. In this work, we modify the DPM algorithm for 4-PAM and obtain a new construction for mapping binary sequences to permutation sequences, where the permutation sequences are obtained by permuting symbols of a 4-PAM constellation. The resulting codebook of permutation sequences formed this way are termed mappings. We also present several metrics for assessing the performance of the mappings from our construction, and we show that a metric called the Sum of Product of Distances (SOPD) is the best metric to use when judging the performance of the mappings. Finally, performance results are presented, where the mappings from our construction are compared against each other and also against the conventional mappings in the literature.
Źródło:
International Journal of Electronics and Telecommunications; 2018, 64, 4; 527-533
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Permutation Coding with Injections for Modified PAM System
Autorzy:
Ogunyanda, Opeyemi O.
Shongwe, Thokozani
Swart, Theo G.
Powiązania:
https://bibliotekanauki.pl/articles/226518.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
injection
permutation codes
power line communications
pulse amplitude modulation
jitter
Opis:
Arriving at a good combination of coding and modulation schemes that can achieve good error correction constitutes a challenge in digital communication systems. In this work, we explore the combination of permutation coding (PC) and pulse amplitude modulation (PAM) for mitigating channel errors in the presence of background noise and jitter. Since PAM is characterised with bi-polar constellations, Euclidean distance is a good choice for predicting the performance of such coded modulation setup. In order to address certain challenges facing PCs, we therefore introduce injections in the coding system, together with a modified form of PAM system. This modification entails constraining the PAM constellations to the size of the codeword’s symbol. The results obtained demonstrate the strength of the modified coded PAM system over the conventional PC coded PAM system.
Źródło:
International Journal of Electronics and Telecommunications; 2020, 66, 3; 399-404
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Symulacja przetworników z wyjściowym sygnałem impulsowym modulowanym częstotliwościowo
Simulation of transducers with pulse frequency modulated output signal
Autorzy:
Świsulski, D.
Powiązania:
https://bibliotekanauki.pl/articles/155982.pdf
Data publikacji:
2011
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
sygnał impulsowy modulowany częstotliwościowo
generator sygnału impulsowego
pulse frequency modulation signal
pulse signal generator
Opis:
Tematem artykułu jest generacja sygnałów impulsowych modulowanych częstotliwościowo. Przedstawiono metodę wyznaczenia położenia kolejnych impulsów sygnału dla przykładowych przebiegów. Podano możliwości realizacji metody w postaci przyrządu wirtualnego oraz urządzenia mikroprocesorowego. Przedstawione metody mogą być wykorzystane do symulacji przetworników pomiarowych z wyjściem częstotliwościowym w trakcie testowania systemów pomiarowych.
The subject of the paper is generation of frequency-modulated pulse signals. The method for determining the position of a next pulse signal, e.g. linear, exponential and sinusoidal waveforms, is presented in this paper. Location of the next pulse at time instant ti is determined in such a way that the inverse of the time interval between that pulse and the previous one in time ti-1 is equal to the transducer sensitivity multiplied by the average value of the measured interval between time instances ti-1 and ti (Fig. 1). From equation (6), (8) or (11) one calculates the instances of appearing the output pulses from the generator. The paper shows feasibility of the method in the form of a virtual instrument (computer equipped with acquisition module and time-counter element) and a microprocessor unit (Fig. 3). In Section 4 the impact of the quantization error on the accuracy is discussed. The experimental results (Fig. 4) confirmed that this error had the greatest impact on the accuracy of determining time between the pulses. The presented method can be used for simulations of transducers with frequency output during tests of measurement systems.
Źródło:
Pomiary Automatyka Kontrola; 2011, R. 57, nr 12, 12; 1528-1530
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design of a Class-D Audio Amplifier With Analog Volume Control for Mobile Applications
Autorzy:
El Khadiri, K.
Qjidaa, H.
Powiązania:
https://bibliotekanauki.pl/articles/226924.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
class D amplifier
analog volume control
pulse width modulation (PWM)
ramp generator
Opis:
A class-D audio amplifier with analog volume control (AVC) for portable applications is proposed in this paper. The proposed class-D consist of two sections. First section is an analog volume control which consists of an integrator, an analog MUX and a programmable gain amplifier (PGA). The AVC is implemented with three analog inputs (Audio, Voice, FM). Second section is a driver which consists of a ramp generator, a comparator, a level shifter and a gate driver. The driver is designed to obtain a low distortion and a high efficiency. Designed with 0.18 um 1P6M CMOS technology, the class-D audio amplifier with AVC achieves a total root-mean-square (RMS) output power of 0.5W, a total harmonic distortion plus noise (THD+N) at the 8-Ω load less than 0.06% and a power efficiency of 90% with a total area of 1.74 mm2.
Źródło:
International Journal of Electronics and Telecommunications; 2016, 62, 2; 187-198
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ metody akwizycji sygnałów częstotliwościowych na dokładność pomiaru
Effect of the method of frequency signal acquisition on the measurement accuracy
Autorzy:
Świsulski, D.
Pawłowski, E.
Powiązania:
https://bibliotekanauki.pl/articles/155228.pdf
Data publikacji:
2013
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
akwizycja sygnałów
sygnał impulsowy modulowany częstotliwościowo
signal acquisition
pulse frequency modulation signal
Opis:
W artykule przedstawiono metody przetwarzania impulsowego sygnału częstotliwościowego. Opisane metody pozwalają na odtworzenie wartości wielkości mierzonej w stałych odstępach czasu w trybie on-line i off-line. Przeprowadzono symulację pomiaru prędkości obrotowej przetwornikiem obrotowo-impulsowym, wyznaczając wartości błędu pomiaru i efektywnej liczby bitów. Wykazano mniejszą wartość błędu i większą wartość efektywnej liczby bitów dla metody wykorzystującej dwa przedziały między-impulsowe.
Methods for processing a frequency-modulated pulse signal are presented in this paper. The methods allow acquiring information about the frequency of a pulse signal with constant sampling frequency. These methods, depending on the time instant for which the measurement result is determined, can be divided into two groups. In measurements on-line the measured value is determined based only on the position of pulses preceding the moment of measurement. The method in which the measured value is determined from the last period and that in which the measured value is determined from extrapolation of two last periods (Fig. 1) are described. In measurements off-line, first there is saved the location of all pulses in the time of recording, and after there is determined the value measured in the assumed moments of the measurement. Therefore, in this case the measured value is determined not only by the position of pulses before the moment of measurement, but also those occurring after this time. The method in which the measured value is determined from the current period and that in which the measured value is determined from interpolation of two periods (Fig. 2) are described in the paper. The accuracy of conversion is determined by a relative error or the number of bits, and thus by the resolution. The noise added to the useful signal has a significant impact on the processing accuracy in real measurements. Therefore the ENOB (Effective Number of Bits), the number of digital signal bits above the noise, is more useful than the resolution. The paper presents examples of simulation results for speed measurements (Tables 1, 2). As it can be seen from the results, increase in the standard generator frequency allows increasing the effective number of bits only to a certain limit. Further increase in the frequency does not increase the ENOB value due to the noise being a result of the method used.
Źródło:
Pomiary Automatyka Kontrola; 2013, R. 59, nr 4, 4; 357-359
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Single-source three-phase switched-capacitor-based MLI
Autorzy:
Jena, Kasinath
Gupta, Krishna Kumar
Bhatnagar, Pallavee
Jain, Sanjay K.
Stala, Robert
Waradzyn, Zbigniew
Piróg, Stanisław
Penczek, Adam
Mondzik, Andrzej
Skała, Aleksander
Powiązania:
https://bibliotekanauki.pl/articles/2175942.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
multilevel inverter
switched capacitor
multicarrier pulse width modulation
cost function
ANPC inverter
Opis:
This article proposes a novel three-phase inverter based on the concept of switched capacitors (SCs), which uses a single DC source. A three-phase, seven-level line-to-line output voltage waveform is synthesised by the proposed topology, which includes eight switches, two capacitors, and one diode per phase leg. The proposed topology offers advantages in terms of inherent voltage gain, lower voltage stresses on power switches, and a reduced number of switching components. Additionally, the switched capacitors are self-balanced, thereby eliminating the need for a separate balancing circuit. The proposed structure and its operating principle, the self-balancing mechanism of the capacitors, and the control strategy are all thoroughly explained in the article. The proposed topology has also been compared with some recent SC topologies. Lastly, the proposed topology has been shown to be feasible through simulation and experimentation.
Źródło:
Power Electronics and Drives; 2022, 7, 42; 197--209
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Averaged models of pulse-modulated DC-DC power converters. Part II. Models based on the separation of variables
Autorzy:
Janke, W.
Powiązania:
https://bibliotekanauki.pl/articles/140855.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power converters
pulse width modulation (PWM)
BUCK
buck-boost
BOOST
averaged models
Opis:
The separation of variables approach to formulate the averaged models of DC-DC switch-mode power converters is presented in the paper. The proposed method is applied to basic converters such as BUCK, BOOST and BUCK-BOOST. The ideal converters or converters with parasitic resistances, working in CCM and in DCM mode are considered. The models are presented in the form of equation systems for large signal, steady-state and small-signal case. It is shown, that the models obtained by separation of variables approach differ in some situations from standard models based on switch averaging method.
Źródło:
Archives of Electrical Engineering; 2012, 61, 4; 633-654
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Averaged models of pulse-modulated DC-DC power converters. Part I. Discussion of standard methods
Autorzy:
Janke, W.
Powiązania:
https://bibliotekanauki.pl/articles/140859.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power converters
pulse width modulation (PWM)
BUCK
BOOST
buck-boost
averaged models
Opis:
The averaged models of switch-mode DC-DC power converters are discussed. Two methods of averaged model derivation are considered - the first, based on statespace averaging and the second, on the switch averaging approach. The simplest converters: BUCK, BOOST and BUCK-BOOST working in CCM (continuous conduction mode) or DCM are taken as examples in detailed considerations. Apart from the ideal converters, the more realistic case of converters with parasitic resistances is analyzed. The switch averaging approach is used more frequently than the other and is believed to be more convenient in practical applications. It is shown however, that in the deriving the averaged models based on the switch-averaging approach, some informalities have been made, which may be the source of errors in the case of converters with parasitic resistances, or working in DCM mode.
Źródło:
Archives of Electrical Engineering; 2012, 61, 4; 609-631
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Metody symulacji przetwornika z impulsowym sygnałem wyjściowym modulowanym częstotliwościowo
Simulation methods for the converter with a pulse frequency modulated output signal
Autorzy:
Pawłowski, E.
Świsulski, D.
Powiązania:
https://bibliotekanauki.pl/articles/154435.pdf
Data publikacji:
2014
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
sygnał impulsowy modulowany częstotliwościowo
symulacja sygnału impulsowego
pulse frequency modulation signal
simulation of pulse signal
Opis:
W artykule przedstawiono porównanie zaproponowanych przez autorów metod symulacji wyjściowego sygnału impulsowego przetwornika napięcieczęstotliwość U/F. Pierwsza z analizowanych metod oparta jest na modelu fizycznym przetwornika, druga na jego równaniu matematycznym. Mimo odmiennego podejścia otrzymano zbliżone wyniki. W pierwszej metodzie uzyskano wyniki obarczone błędami kwantowania o rozkładzie jak w rzeczywistym układzie pomiarowym. W drugiej metodzie wyniki są dokładniejsze, ale nie są związane z techniczną realizacją układu pomiarowego.
In measurement engineering, while processing any quantities into digital form, frequency-modulated impulse signals are often used as intermediate signals. During actuation or monitoring of measurement systems with such sensors it is necessary to have an impulse signal correspondent with the signal from the converter during normal operation. That is why there are being developed the methods which allow generating an impulse signal correspondent to the signal from the converter, when taking into account the changes of the measured quantity in accordance with the adopted characteristics. The paper presents a comparison of the methods for simulating the output impulse signal proposed by the authors, on the example of a voltage-to-frequency U/F converter. The first analyzed method, described in Section 2, is based on a physical model of the converter, while the second, presented in Section 3, is based on its mathematical equation. In spite of the difference of approaches, very similar results were obtained - they are given in Section 4. The advantage of the first method is the acquisition of results encumbered with quantization errors of the distribution precisely the same as in an actual measurement system (Fig. 2). The second method allows acquiring more precise results, which reflect the actual location of subsequent impulses. However, they are not related to any specific technical implementation of the measurement system. The selection of the method depends on the purpose of the simulation of the frequency signal, e.g. researching quantization errors, testing algorithms of increasing the effective resolution of the measurement chain or testing the characteristics of the algorithms of digital processing of frequency signals.
Źródło:
Pomiary Automatyka Kontrola; 2014, R. 60, nr 8, 8; 599-602
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation on Control Strategies for a Single-Phase Photovoltaic Inverter Using PSCAD/EMTDC Software
Autorzy:
Henz, Cristiano Luiz
Gasparin, Fabiano Perin
Powiązania:
https://bibliotekanauki.pl/articles/1956010.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
DC/DC converter
DC/AC converter
photovoltaic module
pulse width modulation
solar energy
Opis:
In the last decades, electric power produced through photovoltaic conversion has been increasing because of the need to reduce fossil fuel burning. Recently, photovoltaic systems have become more competitive and their role in the renewable energies market share is steadily gaining in importance. Improvements in the power electronics employed in the DC/AC conversion are topics of interest in the quest for more efficient and eventually reduced-cost inverters. The goal of this paper is to perform an investigation of control strategies and propose a topology for a single-phase DC/AC converter for photovoltaic arrays using the simulation software Power System Computer Aided Design/Electromagnetic Transient Design and Control (PSCAD/EMTDC). The circuit proposed in this paper employs an isolating transformer to a grid-connected photovoltaic inverter. The control strategy proposed uses the instantaneous reactive power theory (p–q theory) and phase-locked loop (PLL). The p-q theory uses two virtual axes in the Park Transformation, which provide to the control system a good dynamic response, accuracy, and decoupling between the control and power system. Computer simulations using the electromagnetic transient software PSCAD show the efficiency of the proposed strategy for a single-phase inverter. The control strategy and topology are quite simple and easy to implement in the future using a Digital Signal Processor (DSP). The results provide insights into new power electronics solutions, which can improve the efficiency and efficacy of the current available in DC/AC converters for photovoltaic systems.
Źródło:
Power Electronics and Drives; 2021, 6, 41; 75-99
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dimming control schemes combining IEEE 802.15.7 and SC-LPPM modulation schemes with an adaptive M-QAM OFDM for indoor LOS VLC systems
Autorzy:
Mohammed, Nazmi A.
Badawi, Kareem A.
Khalaf, Ashraf A. M.
El-Rabaie, El-Sayed
Powiązania:
https://bibliotekanauki.pl/articles/1818230.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
visible light communication
sub-carrier pulse position modulation
lightning topologies
bit error rate
Opis:
The presented work proposes a new dimming control schemes for indoor visible light communication which combines variable pulse-position modulation, colour shift keying as key schemes of IEEE 802.15.7 standard, and sub carrier-pulse-position modulation as a pulse-position modulation variant with orthogonal frequency division multiplexing. These schemes are then compared with traditional merging schemes utilizing pulse-width modulation and multiple pulse-position modulation with m-ary quadrature amplitude modulation OFDM. The proposed schemes are investigated in a typical room with a different lighting layout (i.e., distinctive and uniform lighting layout), followed by an illumination investigation to evaluate the performance of the proposed schemes, especially the enhanced achieved data rates, and to determine their limitations as reliable visible light communication systems that can satisfy both communication and illumination requirements.
Źródło:
Opto-Electronics Review; 2020, 28, 4; 203--212
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocena narażenia pracowników na promieniowanie mikrofalowe wytwarzane przez radary
Assessment of workers exposure to microwave radiation generated by radars
Autorzy:
Kieliszek, Jarosław
Powiązania:
https://bibliotekanauki.pl/articles/23352068.pdf
Data publikacji:
2022
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
radary
promieniowanie mikrofalowe
modulacja impulsowa
narażenie na impulsowe pole mikrofalowe
radars
microwave radiation
pulse modulation
exposure to pulsed microwave field
Opis:
W pracy przedstawiono specyfikację urządzeń radiolokacyjnych wytwarzających silne, impulsowe pola mikrofalowe oraz określono narażenie pracowników na ten typ promieniowania elektromagnetycznego. Przedstawiono również uwarunkowania metrologiczne realizacji pomiarów impulsowego promieniowania mikrofalowego emitowanego przez radary. Przedstawiono międzynarodowe rekomendacje dotyczące limitowania natężenia pola elektrycznego. Zostały również przedstawione uwarunkowania krajowych limitów ustanowione w przepisach oraz zaproponowano ujednolicone podejście do metrologii impulsowego pola mikrofalowego.
In the work the specification of radar devices emitting strong, pulsed microwave fields and the exposure conditions of workers have been presented. One presented analyses of international rules of the protection of workers exposed to this radiation type. The Polish conditionings of rules of the safety of workers exposed to pulsed microwave field have been described and the unified approach to the metrology of the pulsed microwave field was proposed.
Źródło:
Podstawy i Metody Oceny Środowiska Pracy; 2022, 4 (114); 39--52
1231-868X
Pojawia się w:
Podstawy i Metody Oceny Środowiska Pracy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the FPAA to Sample Input Signal for Laboratory Exercise: Pulse Amplitude Modulation
Autorzy:
Grzechca, Damian
Chruszczyk, Lukas
Powiązania:
https://bibliotekanauki.pl/articles/227335.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
field programmable analog array (FPAA)
signal processing
pulse amplitude modulation (PAM)
student laboratory
Opis:
This paper presents exemplary exercise on the fundamentals of signal processing course which is offered for second year bachelor level students. Application of Field Programmable Analog Array (FPAA) for pulse amplitude modulation (PAM) exercise is described with signal processing laboratory. There are presented two methods for implementing PAM modulation and demodulation technique in FPAA module. Example configuration files are available form Authors’ web site.
Źródło:
International Journal of Electronics and Telecommunications; 2020, 66, 1; 25-28
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ergodic Channel Capacity of PPM-Coded Optical MIMO Communications Under Combined Effects
Autorzy:
Cao, Minghua
Zhang, Yue
Kang, Zhongjiang
Wang, Huiqin
Powiązania:
https://bibliotekanauki.pl/articles/1844525.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
atmospheric channel
ergodic channel capacity
pulse position modulation
spatial correlation
optical wireless communication
Opis:
The ergodic channel capacity of wireless optical multiple-input multiple-output (MIMO) system with pulse position modulation (PPM) is investigated. The combined effects of atmospheric turbulence, atmospheric attenuation, pointing error and channel spatial correlation are taken into consideration. The expression of ergodic channel capacity is derived, and is further performed by Wilkinson approximation method for simplicity. The simulation results indicated that the strong spatial correlation has the greatest influence on the ergodic channel capacity, followed by pointing errors and atmospheric turbulence. Moreover, the ergodic channel capacity growth brought by space diversity only performs well under independent and weakly correlated channels. Properly increasing the size and spacing of the receiving apertures is an effective means of effectively increasing the ergodic channel capacity.
Źródło:
International Journal of Electronics and Telecommunications; 2021, 67, 3; 431-436
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dimming control schemes combining IEEE 802.15.7 and SC-LPPM modulation schemes with an adaptive M-QAM OFDM for indoor LOS VLC systems
Autorzy:
Mohammed, Nazmi A.
Badawi, Kareem A.
Khalaf, Ashraf A. M.
El-Rabaie, S.
Powiązania:
https://bibliotekanauki.pl/articles/1818236.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
visible light communication
sub-carrier pulse position modulation
lightning topologies
bit error rate
Opis:
The presented work proposes a new dimming control schemes for indoor visible light communication which combines variable pulse-position modulation, colour shift keying as key schemes of IEEE 802.15.7 standard, and sub carrier-pulse-position modulation as a pulse-position modulation variant with orthogonal frequency division multiplexing. These schemes are then compared with traditional merging schemes utilizing pulse-width modulation and multiple pulse-position modulation with m-ary quadrature amplitude modulation OFDM. The proposed schemes are investigated in a typical room with a different lighting layout (i.e., distinctive and uniform lighting layout), followed by an illumination investigation to evaluate the performance of the proposed schemes, especially the enhanced achieved data rates, and to determine their limitations as reliable visible light communication systems that can satisfy both communication and illumination requirements.
Źródło:
Opto-Electronics Review; 2020, 28, 4; 203--212
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
DC-link voltage balancing in cascaded H-Bridge converters
Autorzy:
Lewicki, A.
Powiązania:
https://bibliotekanauki.pl/articles/141491.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cascaded H-Bridge converter
DC-link voltage balancing
space-vector pulse width modulation
Opis:
In this paper a DC-link voltage balancing strategy for multilevel Cascaded H-Bridge (CHB) converter is proposed. Presented solution bases on optimal choice of active vector durations in Space-Vector Pulse Width Modulation (SV-PWM). It makes it possible to DC-link voltages control and to properly generate the output voltage vector in the case of DC-link voltage unbalance. Results of simulation and experimental researches on proposed control strategy are presented in the paper.
Źródło:
Archives of Electrical Engineering; 2014, 63, 3; 439-455
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of PWM to trajectory accuracy in mobile robot motion
Autorzy:
Beniak, R.
Pyka, T.
Powiązania:
https://bibliotekanauki.pl/articles/384557.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
mobile robot control
kinematic and dynamic control
castor sliding wheel
pulse width modulation (PWM)
Opis:
The paper compares simulation results for direct and PWM control of DC motors in a tri-wheel mobile robot with a castor sliding wheel. Our aim was to determine to what extent PWM control changes the trajectory accuracy. For this purpose, we compare kinematic and dynamic control. To make the model more realistic, we considered the impact of viscous and rolling friction of driving wheels on the motion along the trajectory. We conclude that dynamic control is of higher quality as compared to kinematic control, and that there is a significant impact of PWM control on the trajectory accuracy.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2012, 6, 4; 50-56
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development and tests of PWM amplifier for driving the piezoelectric elements
Autorzy:
Matiulko, J.
Poźniak, T.
Przygoda, K.
Grecki, M.
Powiązania:
https://bibliotekanauki.pl/articles/397949.pdf
Data publikacji:
2010
Wydawca:
Politechnika Łódzka. Wydział Mikroelektroniki i Informatyki
Tematy:
wzmacniacz PWM (modulacja szerokości impulsu)
piezoelektryczne elementy
PWM (pulse width modulation) amplifier
piezoelectric elements
Opis:
The paper describes the design and research work carried out to prepare the prototype of pulse amplifier. The work was aimed to describe main operational parameters of PWM amplifiers enabling using them to control the piezoelectric actuators used for active compensation of Lorentz force detuning of superconducting cavities.
Źródło:
International Journal of Microelectronics and Computer Science; 2010, 1, 1; 69-72
2080-8755
2353-9607
Pojawia się w:
International Journal of Microelectronics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Grid-Tied Neutral Point Clamped based Centralised Photovoltaic Inverter with Improved DC Link Voltage Balancing and Harmonic Minimisation Control
Autorzy:
Bhowmick, Supratik
Mukherjee, Debranjan
Maiti, Suman
Chakraborty, Chandan
Powiązania:
https://bibliotekanauki.pl/articles/1955983.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
photovoltaic multilevel inverter
neutral point voltage balancing
space vector pulse width modulation
current harmonic minimisation
Opis:
This paper proposes an improved space vector pulse width modulation (SVPWM) based DC link voltage balancing control of a three-phase three-level neutral point clamped (NPC) centralised inverter supplying the generated power from photo voltaic (PV) array to a three-phase utility grid. Two possible schemes have been developed based on the power conversion stage between PV array and the utility grid namely, two-stage (three-level boost converter three-phase three-level NPC inverter) and single-stage (three-phase three-level NPC inverter alone). The comparison between these two schemes has been thoroughly discussed in terms of the control strategies employed, power loss analysis and efficiency. The performance of the centralised inverter under different modes of operation has been investigated by developing the required control strategies for smooth operation. Using the proposed control strategy, the centralised inverter can be operated as a static synchronous compensator (STATCOM) during night time, if needed. The power loss incurred in the power-electronic converters has been analysed for constant and also for variable ambient temperature. The effectiveness of the centralised inverter as an active filter (AF) has also been verified when a three-phase non-linear load is considered in the system.
Źródło:
Power Electronics and Drives; 2021, 6, 41; 185-203
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Bidirectional Buck-Boost Converter-Based Switching Ripple Communication Strategy for Intelligent Street Lighting Systems
Autorzy:
Zhang, Yixuan
Hu, Yihua
Tse, Zion
Liu, Yuwei
Deng, Jiamei
Xu, Hui
Wang, Yangang
Li, Wei
Powiązania:
https://bibliotekanauki.pl/articles/1955998.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
bidirectional switching ripple communication
buck-boost converter
intelligent street lighting system
pulse width modulation
smart city
Opis:
The light-emitting diode (LED) is an essential component of intelligent street lighting (ISL) systems. An efficient ISL system can not only reduce power consumption by planning LED illuminating time but also reduce maintenance costs through a high degree of automation. In this paper, a buck-boost converter is used to realise composite transmission of power and signals for an ISL system. The power is modulated by the pulse width modulation (PWM) approach, and the switching ripple generated in the PWM process is utilised as the carrier of the signals transmitted between the remote-control centre and the slave nodes. Moreover, the proposed model involves a ‘request to send (RTS)/confirm to send (CTS)’ mechanism to avoid signal conflicts. Compared with the conventional power line communication (PLC) approach, the proposed transmission scheme has the advantages of simple circuit structure and simple system wiring. Additionally, a simulation model built in MATLAB/Simulink proves the designed transmission method has strong anti-noise ability.
Źródło:
Power Electronics and Drives; 2021, 6, 41; 260-275
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Galvanic separation of analogue signals
Separacja galwaniczna sygnałów analogowych
Autorzy:
Molenda, T.
Chmielarz, S.
Powiązania:
https://bibliotekanauki.pl/articles/1361023.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
sygnały analogowe
separacja galwaniczna
PWM
linearyzacja
galvanic separation
analogue systems
pulse width modulation (PWM)
nonlinearity correction
Opis:
The article deals with the issues of galvanic separation of analogue circuits and methods to perform it. The authors described capacitive, inductive and optical couplings, separation with the use of processing as well as non-linearity correction of optoelectronic materials characteristics. The available solutions were presented and their characteristics.
Artykuł poświęcony jest zagadnieniom związanym z separacją galwaniczną obwodów analogowych i sposobom jej realizacji. Opisano w nim sprzężenia pojemnościowe, indukcyjne i optyczne, separację z zastosowaniem przetwarzania oraz linearyzację charakterystyk elementów optoelektronicznych. Przedstawiono dostępne rozwiązania i ich właściwości.
Źródło:
Mining – Informatics, Automation and Electrical Engineering; 2016, 54, 3; 5-10
2450-7326
2449-6421
Pojawia się w:
Mining – Informatics, Automation and Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Poprawa sprawności energetycznej urządzeń spawalniczych
Improving the energy efficiency of welding machines
Autorzy:
Stopczyk, W.
Nawrocki, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1367490.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Napędów i Maszyn Elektrycznych Komel
Tematy:
sprawność energetyczna
GMAW
układ rezonansowy LLC
modulacja gęstości impulsów
energy efficiency
LLC resonant circuit
pulse density modulation
Opis:
This article addresses the topic of improving the energy efficiency of welding machines with GMAW system (Gas Metal Arc Welding). The research tested the influence of various design solutions on their efficiency. Three basic groups of welding machines were examined, with the machines representing various design solutions: transformer, thyristor and inverter. These are the typical welding machines produced currently by one of the manufacturers of professional welding equipment. Design solutions of these welding machines tested within the scope of the selected properties are equally representative of the group of welding machines produced by the global leading manufacturers of welding equipment. The proposed solutions demonstrated the efficiency of the machines. Research results were presented and discussed. It has been proved that the adopted the design solution has the major impact on the efficiency of the welding machines. Another part of the article focused on the inverter machines. Electrical scheme of the resonant LLC welding machine was presented. The results of the resonant welding machines simulation studies for various control methods were presented. The operation of the resonant welding machine for various control methods was simulated and presented. The operation of the resonant welding machine was simulated by the application of the output Power control performed by the pulse density modulation and phase control method. Next, the comparison was made between the losses of switching on and off the transistors operating in the bridge circuit at zero and non-zero values of the drain current and drain-source voltage. The results of measurements and simulations were summarized.
W artykule zajęto się zagadnieniem poprawy sprawności energetycznej urządzeń spawalniczych spawających metodą GMAW (Gas Metal Arc Welding). Badano wpływ różnych rozwiązań konstrukcyjnych urządzeń na ich sprawność. Przebadano trzy podstawowe grupy urządzeń spawalniczych, reprezentujących różne rozwiązania konstrukcyjne: transformatorowe, tyrystorowe i inwertorowe. Są to typowe, obecnie produkowane urządzenia jednego z producentów profesjonalnych urządzeń spawalniczych. Rozwiązania konstrukcyjne tych urządzeń w zakresie analizowanych właściwości reprezentowały analogiczne grupy urządzeń głównych światowych producentów urządzeń spawalniczych. Pokazano, jak na tle tych rozwiązań wypada ich sprawność. Przedstawiono i omówiono wyniki badań. Wykazano zasadniczy wpływ przyjętego rozwiązania konstrukcyjnego na sprawność urządzenia spawalniczego. W dalszej części artykułu skupiono się na urządzeniach inwertorowych. Pokazano układ elektryczny spawarki rezonansowej LLC. Przedstawiono wyniki badań symulacyjnych rezonansowego urządzenia spawalniczego dla różnych metod sterowania. Symulowano pracę urządzenia przy zastosowaniu regulacji mocy wyjściowej metodą modulacji gęstości impulsów i sterowania fazowego. Porównano straty załączania i wyłączania tranzystorów pracujących w układzie mostkowym przy zerowych i niezerowych wartościach prądu drenu i napięcia dren-źródło. Podsumowano wyniki pomiarów i symulacji.
Źródło:
Maszyny Elektryczne: zeszyty problemowe; 2016, 3, 111; 35-40
0239-3646
2084-5618
Pojawia się w:
Maszyny Elektryczne: zeszyty problemowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Soft-Output STBC Decoder for Aeronautical Telemetry
Autorzy:
Louёt, Yves
Othman, Rami
Skrzypczak, Alexandre
Powiązania:
https://bibliotekanauki.pl/articles/309130.pdf
Data publikacji:
2020
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
continuous-phase modulation
CPM
pulse amplitude modulation
PAM
shaped offset quadrature phase shift keying
SOQPSK
space-time block coding
STBC
ternary symbol
Opis:
Alamouti encoding is a well-known space time block encoding technique used to improve the received signal quality in Rayleigh fading channels. In aeronautical telemetry, this encoding technique is applied to shaped offset quadrature phase shift keying tier generation (SOQPSK-TG) modulation in order to handle the two-antenna issue. It is provided for in telemetry-related IRIG standards. In this paper, we propose a unique decoding architecture for Alamouti-encoded SOQPSK-TG signals, taking advantage of pulse amplitude modulation decomposition with soft and hard outputs. We exploit this result to obtain a Viterbi algorithm (VA) for hard decoding and a soft output Viterbi algorithm (SOVA) for soft and hard decoding, with a twofold benefit: operation using one trellis structure, unlike decoders that are based on the 8-waveforms cross-correlated trellis-coded quadrature modulation (XTCQM) approximation, and very attractive bit error rate performance, as well as a complexity trade-off.
Źródło:
Journal of Telecommunications and Information Technology; 2020, 1; 13-20
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
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