Ograniczanie wyników
Czasopisma help
Autorzy help
Lata help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 99

Liczba wyników na stronie
first rewind previous Strona / 5 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  Matlab
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 5 next fast forward last
PL
Artykuł opisuje przyjętą metodę uzyskiwania kątowego profilu indukcyjności uzwojenia silnika, w której podstawa jest charakterystyczne przetwarzanie danych pomiarowych uzyskiwanych z dedykowanego stanowiska laboratoryjnego. Podstawą przedstawionej analizy jest badanie przebiegu prądu w towarzystwie wymuszającego go napięcia ujawniając tym samym skończoną dynamikę obwodu RL. Uzasadnieniem użytego określenia precyzyjne jest uwzględnienie nieliniowej funkcji aproksymacji modelującej przebieg prądu w zestawieniu do innych, uproszczonych metod w połączeniu z relatywnie złożonym procesem filtrowania i ekstrakcji wektorów danych. Wybrane parametry procesu poddano analizie statystycznej celem określenia optymalnych nastaw procesu. Uzyskane rezultaty wstępnie sprawdzono pod kątem powtarzalności oraz opisano dalsze kierunki badań.
EN
The article describes the adopted method of obtaining the angular inductance profile of the motor winding. The method basis on the characteristic processing of measurement data obtained from a dedicated laboratory stand. The basis of the presented analysis is the study of the current waveform in the presence of the voltage forcing it, thus revealing the finite dynamics of the RL circuit. The rationale for the precise term used is to take into account the nonlinear approximation function modeling the current waveform in comparison to other, simplified methods. What is equally important, certain parameters of the acquisition process were adopted as a consequence of the performed statistical analysis. Parameterization of the process is possible thanks to the proprietary design of the test stand, which additionally allows for high angular resolution of measurements. The obtained results were initially checked for repeatability and further research directions were described.
EN
The article presents issues related to the possibility of using an artificial neural network to classify factors describing the lightning hazard. It also analyzed the selection of the most optimal type of neural network for this type of task, as well asthe issue of input data, which both teach the neural network and form the basis for the final classification. Finally, the conclusions and assumptions necessary for the practical implementation of the task were drawn. The practical part of the task is planned as the following consideration stage.
PL
W artykule została przedstawiona problematyka związana z możliwością wykorzystania sztucznej sieci neuronowej do przeprowadzenia klasyfikacji współczynników opisujących zagrożenie piorunowe. Przeanalizowano wybór najbardziej optymalnego rodzaju sieci neuronowej dla tego rodzaju zadania, a także kwestię danych wejściowych, które posłużą zarówno do uczenia sieci neuronowej, jak również stanowią podstawę do końcowej klasyfikacji. Na koniec wyciągnięte zostały wnioski oraz założenia niezbędne do praktycznej realizacji zadania. Praktyczna część zadania będzie stanowić kolejny etap rozważań.
EN
The purpose of this work is to create a Matlab toolbox that makes it easy and accessible to get acquainted with a novel control method called type-2 fuzzy controller. A toolbox for working with type-1 controllers can be found in the Simulink package, while there is only few, simple toolboxes for type-2 fuzzy controllers. The article describes the details of the created software, which allows you to work both with simulation objects, but also enables you to create program code for an PLC industrial controller. This gives you the opportunity to work in a simulation environment with a model of the control object and then, after tuning the controller, to automatically implement the controller to control the real object. In the literature, you can find many methods for reducing type-2 to type-1 fuzzy logic, but most often they are compared to several well-known classical reduction methods, such as the KM algorithm. There is no compilation of the most popular methods and a comparison of their performance. With the new toolbox it was possible to quickly create and add new reduction methods so in the article an analysis of 16 reduction methods is also presented.
EN
This article presents research carried out using physical data from the experimental construction of an overhead crane. This article aims to determine the dynamic behaviour of the cart-pendulum system when the hoisting mechanism hits the new bumper design at the end of the girder support structure with selected speed and bumper material to the length of the wire rope. This research shows the influence of the horizontal speed of the hoisting mechanism on the bumper force during a collision with a standard buffer and its modifications. The presented model can be the basis for modelling more complex cases, and its assumed role (i.e. the ability to determine the angle of deflection of the rope during an impact) has been confirmed and is possible to use in a specific case of an overhead crane on an industrial scale. Preliminary analysis of the construction of the bumper considered reveals its positive features, aiming, among other goals, to reduce the acceleration and force acting on the crane cart in emergency situations.
EN
The paper presents the comparative analysis of the use a two-level, three-level and five-level voltage source inverter (VSI) for supplying a five-phase synchronous motor with permanent magnets (PMSM). The motor was controlled by Indirect Field Oriented Control (IFOC) with Space Vector Modulation (SVM). Simulation tests showing influence of the inverter topology on the drive system were performed in the Matlab/Simulink environment for various values of the switching frequency - from 1 to 30 kHz. The aim of the presented simulation research is analysis of the prototype five-phase PMSM machine and preliminary development of the power supply system based on multilevel inverters. As a result it will allow to correct determination of the rated parameters of the selected devices (mainly the measurement system and semiconductors). The created model can also be used as part of a larger simulation system, e.g. in an electric vehicle.
PL
W pracy przedstawiona została analiza porównawcza zastosowania dwupoziomowego, trójpoziomowego oraz pięciopoziomowego falownika napięcia (VSI) służącego do zasilania pięciofazowego silnika synchronicznego z magnesami trwałymi. Do sterowania układu napędowego zaimplementowano tzw. sterowanie polowo-zorientowane pośrednie (IFOC) z użyciem modulatora wektora przestrzennego SVM (Space Vector Modulation). Przeprowadzone badania symulacyjne w środowisku Matlab/Simulink zostały wykonane dla różnych wartości częstotliwości kluczowania – od 1 do 30 kHz. Celem prezentowanych badań symulacyjnych jest analiza prototypowej pięciofazowej maszyny PMSM oraz wstępne opracowanie układu zasilania opartego na falownikach wielopoziomowych. W rezultacie pozwoli to na poprawne określenie parametrów znamionowych wybranych urządzeń (głównie układu pomiarowego i półprzewodników). Stworzony model może być również wykorzystany w ramach większego systemu symulacyjnego, np. w pojeździe elektrycznym.
EN
Mathematical package Matlab is a very convenient programming language, used for calculations in the field of linear algebra for scientists and engineers. Its main advantage for civil engineers is the simplicity of the language and the wide range of application in the field of linear statics. This mathematical platform was used for programming of static calculations of multi-span, continuous, beam bridge structures. In the formulated theoretical approach, the internal forces were calculated using the method of forces. Knowing the influence matrix and load values in the unit states, the envelope of internal forces can be determined. The first step is entering the vector of loads and the second is calculating an envelope using special function. Obtaining the results from individual loads in a variety of operating conditions, it is possible to calculate the global envelope of internal forces and proceed with modifications of the model. The theoretical approach was computationally tested on the example of an alternative design concept of the MA-46 bridge along the A4 motorway. One of the biggest advantages of the discussed computational approach is the wide access to the results of intermediate calculations. Another benefits of working with mathematical packages are improving insight in the field of static calculations and getting used to working with code like in some programs for structural analysis (e.g. SOFiSTiK). The discussed computational approach is a good way to pre-design due to the little time required to compare several variants of solution, so it can be helpful in optimizing the structure.
PL
Pakiet Matlab jest środowiskiem programistycznym służącym do obliczeń w zakresie algebry liniowej, pomocnym zarówno dla naukowców, jak i dla inżynierów. Znajduje on zastosowanie zarówno przy obliczeniach prostych, jak i bardzo złożonych. Jego główna zaleta z perspektywy inżyniera budowlanego jest prostota języka, niewymagająca dużych umiejętności programistycznych i możliwość szerokiego zastosowania w obliczeniach z zakresu statyki liniowej. Platforma matematyczna została użyta do oprogramowania obliczeń statycznych wieloprzęsłowych, ciągłych, belkowych konstrukcji mostowych. W sformułowanym podejściu teoretycznym wykorzystano metodę sił do wyznaczania wykresów sił wewnętrznych w stanach jednostkowych, które to uporządkowane tworzą macierz wpływu. Mając macierz wpływu, wprowadzano wektor obciążeń, a następnie wyznaczano obwiednie sił przekrojowych przy użyciu specjalnej funkcji. Znając wyniki od poszczególnych obciążeń, możliwe jest wyznaczenie globalnej obwiedni sił wewnętrznych i przystąpienie do ewentualnych modyfikacji modelu. Podejście teoretyczne zostało przetestowane obliczeniowo na przykładzie alternatywnej koncepcji projektowej mostu MA-46 w ciągu autostrady A4. Jedną z większych zalet omówionego podejścia analitycznego jest szeroki dostęp do wyników obliczeń posrednich oraz praca z kodem zbliżonym do niektórych programów obliczeniowych (np. SOFiSTiK). Omówione podejście obliczeniowe jest dobrym sposobem do wstępnego projektowania ze względu na niewielki czas potrzebny do porównania kilku wariantów rozwiązania, a co za tym idzie, może być pomocne w optymalizacji konstrukcji.
EN
In this paper we describe the creation of a model of the motion of a flying object in a geocentric coordinate system (ECEF - Earth-Centered, Earth-Fixed). Such a model can be used to investigate the accuracy and resistance of radio navigation systems to interference. The essence of the design of the model lies in the mathematical description of the motion of a flying object in a geocentric coordinate system. The flight trajectory of a flying object consists of one straight section and two turns. When creating a model, we assume a flight at a constant altitude. In this paper, we present one of the possible procedures for modelling the motion of a flying object in a geocentric coordinate system. We chose the initial coordinates of the flying object according to flightradar 24. We used the Matlab software for computer simulation.
EN
In this paper we solve the problem of the influence of the mutual position of the users of the communication network on the accuracy of the telemetric navigation system. We present the principle of operation of a telemetry navigation system and examine the accuracy of determining the position of users of the communication network depending on their mutual position. The telemetric method of determining the position of users of a communication network can be used in shipping or air transport. The simulation of the telemetry system will be performed in the Matlab software environment.
EN
The section of the paper on simulation studies presents the application of fractional calculus to describe the dynamics of pneumatic systems. In the construction of mathematical models of the analysed dynamic systems, the Riemann-Liouville definition of differ-integral of non-integer order was used. For the analysed model, transfer function of integer and non-integer order was determined. Functions describing characteristics in time and frequency domains were determined, whereas the characteristics of the analysed systems were obtained by means of computer simulation. MATLAB were used for the simulation research. The section of the paper on laboratory research presents the results of the laboratory tests of the injection system of the internal combustion engine with special attention to the verification of simulated tests of selected pneumatic systems described with the use of fractional calculus.
10
EN
Buildings are the main consumer of energy resources in the total energy balance of the countries in Central and Eastern Europe, the main energy consumption is allocated for heating. Efficient use of energy resources for heating needs to a large extent depends on the efficiency of regulation of heating systems. In the article, dynamic mathematical models of a two-room typical apartment in Ukraine, built in 2016, were developed in Matlab and EnergyPlus software environment. The simulations were carried out using IWEC hourly climate data for the city of Kyiv. The results of simulations of thermal energy consumption in Matlab are characterized by a larger range of fluctuations of the heating system load, which is typical for the real operating conditions of the system with the controller of ON/OFF type. In EnergyPlus it is assumed that the gas boiler operates continuously in the ON mode. In the research, the change of load on the apartment heating system was studied at different numbers and locations of air temperature control sensors installation, according to which the controller of the autonomous gas boiler operates.
11
Content available remote Steering structure for a single wheeled vehicle
EN
Nowadays, there is a need to reduce emissions in the world and use electricity to drive vehicles. There is an increasing interest in small passenger vehicles suitable for crowded cities. In this paper it was designed a universal control structure for a single-wheeled vehicle with a tilt sensor. In this structure is possible to apply a vehicle with parallel wheel arrangement. The paper describes a current and position loop with PI and PD controllers suitable for a single wheeled vehicle. It was designed a simple complementary filter for data processing. A complementary filter evaluate the data from accelerometer and gyroscope, which includes all signal processing requirements for control. Additionally, a program block diagram was also designed to be used in any microprocessor. The results and recommendations of the adjustment for further work with the proposed structure are evaluated in the end of the paper.
PL
W artykule zaprezentowano system sterowania jednokołowym pojazdem elektrycznym stosowanym do poruszania się w zatłoczonym mieście. Do kontroli prądu i pozycji pojazdu zastosowano sterowniki PI i PD. Do kontroli ruchu zastosowano czujniki przyśpieszenia oraz pochyelnia ora żyroskop.
12
Content available remote Efficient terrestrial digital video broadcasting receivers based OFDM techniques
EN
This paper presents the design of efficient digital video propagation global receivers based on an orthogonal frequency distribution multiplexing scheme. The technology of DVB-T standards is developed by DVB assignment specifies the framing, modulation, channel, and noise elimination techniques for digital receiver television broadcasting. The OFDM scheme is a particular multicarrier transmission where a single information flow is transmitting in excess of a numeral of lesser speed sub-carrier with enough strength to radio channel effect. This paper provides a top-level simulation of the basic processing include in the transmitted and received OFDM waveforms under physical channel noise. The possibility to carry defined data containers in addition to audio and video transport streams has increased deployed for many services. The suggested structure of the classical digital broadcasting system was designed with permanent modulation methods which used to promise dependable communication even with very aggressive channel effects.
PL
W artykule przedstawiono projekt efektywnych globalnych odbiorników cyfrowej propagacji wideo w oparciu o schemat multipleksowania z ortogonalnym rozkładem częstotliwości. Technologia standardów DVB-T jest opracowywana przez przypisanie DVB, określające techniki ramkowania, modulacji, kanałów i eliminacji szumów dla nadawania telewizji cyfrowej. Schemat OFDM jest konkretną transmisją z wieloma nośnymi, w której pojedynczy przepływ informacji przesyła ponad liczbę mniejszej prędkości podnośnej z wystarczającą siłą dla efektu kanału radiowego. W tym artykule przedstawiono symulację na najwyższym poziomie podstawowego przetwarzania w przesyłanych i odbieranych kształtach fal OFDM w warunkach szumu kanału fizycznego. W wielu usługach wzrosła możliwość przenoszenia zdefiniowanych kontenerów danych oprócz strumieni transportowych audio i wideo. Proponowana struktura klasycznego cyfrowego systemu nadawczego została zaprojektowana z wykorzystaniem trwałych metod modulacji, które zapewniały niezawodną komunikację nawet przy bardzo agresywnych efektach kanałowych.
EN
Purpose: The primary objective of the current study is to numerically model the steel thin-walled curved box-girder bridge and to examine its various response parameters subjected to Indian Railway loading. Design/methodology/approach: The analysis is conducted by adopting a one dimensional curved thin-walled box-beam finite beam element based on finite element methodology. The scope of the work includes a computationally efficient, three-noded, one-dimensional representation of a thin-walled box-girder bridge, which is especially desirable for its preliminary analysis and design phase, as well as a study of the static characteristics of a steel curved bridge, which is critical for interpreting its dynamic response. Findings: The analytical results computed using finite element based MATLAB coding are presented in the form of various stress resultants under the effect of various combinations of Indian Railway loads. Additionally, the variation in different response parameters due to changes in radius and span length has also been investigated. Research limitations/implications: The research is restricted to the initial design and analysis phase of box-girder bridge, where the wall thickness is small as compared to the cross-section dimensions. The current approach can be extended to future research using a different method, such as Extended finite element technique on curved bridges by varying boundary conditions and number of elements. Originality/value: The validation of the adopted finite element approach is done by solving a numerical problem, which is in excellent agreement with the previous research findings. Also, previous studies had aimed at thin-walled box girders that had been exposed to point loading, uniformly distributed loading, or highway truck loading, but no research had been done on railway loading. Moreover, no previous research had performed the static analysis on thin-walled box-girders with six different response parameters, as the current study has. Engineers will benefit greatly from the research as it will help them predict the static behaviour of the curved thin-walled girder bridge, as well as assess their free vibration and dynamic response analysis.
EN
Purpose: Curved box-girder bridges offers an excellent solution to the problems associated with traffic congestion. However, owing to their complex geometry, they are subjected to shear lag, torsional warping and cross-sectional distortion, which must be assessed in their study and design. Furthermore, the dynamic behaviour of curved bridges adds to the complexity of the issue, emphasizing the importance of studying free vibration. The purpose of this study is to numerically model the concrete curved box-girder bridge considering torsional warping, distortion and distortional warping effects and to identify key parameters that influence the free vibration response of the box-girder bridge by validating it with experimental and analytical studies. Design/methodology/approach: The concrete bridge is numerically modelled by means of computationally effective thin-walled box-beam finite elements that consider torsional warping, distortion and distortional warping, which are prominent features of thinwalled box-girders. The free vibration analysis of the concrete curved box-girder bridge is performed by developing a finite element based MATLAB program. Findings: The identification of critical parameters that influence the free vibration behaviour of curved thin-walled concrete box-girder bridges is one of the main findings of the study. Each parameter and its effect has been extensively discussed. Research limitations/implications: The study limits for the preliminary design phase of thin-walled box-girder bridge decks, where a complete three-dimensional finite element analysis is unnecessary. The current approach can be extended to future research using a different method, such as finite element grilling technique on multi-span curved bridges having unequal span. Originality/value: The current research implements a finite element formulation in combination with thin-walled beam theory, where an extensive parametric study is conducted on the free vibration behaviour of a concrete thin-walled box-girder bridge, while also accounting for their complex structural actions. The validity of the given numerical formulation is demonstrated by a comparison of the natural frequencies found experimentally. The study carried out will be of great importance for engineers to help them anticipate the modal characteristics of a curved concrete thin-walled girder bridge, which will further be useful for evaluating their dynamic response analysis.
PL
W artykule wykorzystano oprogramowanie MatLab do opracowania strukturalno-matematycznego modelu fragmentu systemu elektroenergetycznego, zawierającego wyłącznik, linie zasilania o parametrach rozłożonych oraz asymetryczne rezystancyjno-indukcyjne obciążenie. Na podstawie opracowanego modelu prowadzone są badania zwarć jednofazowych w linii. Wyniki symulacji komputerowej przedstawiono w postaci rysunków, które są analizowane.
EN
The article presents the application of the MatLab software to develop a structural-mathematical model as part of the power system, containing circuit breaker, power lines with distributed parameters and asymmetric resistive-inductive load. Based on the developed model, there are conducted tests of single-phase short-circuits in line. The results of the computer simulation are shown as the drawings that are analyzed.
EN
Modern gantry cranes are an indispensable element of large industrial and transport enterprises. Port handling equipment is operated under conditions of complex spatial loading of varying intensity, as well as under conditions when the walls of structural elements are thinned in the crane carrier system. During the operation of handling equipment in ports, at construction sites, in machine-building industries, in addition to the external load, aggressive media act on the carrier system elements, which leads to various types of wear: corrosive, abrasive and mechanical. Monitoring of the state of handling equipment structures is a very important task of diagnosing the state of the material of elements of the carrier system of cranes and transporting machines. An important and urgent scientific and technical problem of taking into account the influence of aggressive environment on the stress-strain state of the metal structures of gantry cranes is considered. It is noted that during corrosion, a significant thinning of the walls of structural elements occurs. The safety of crane operation requires this factor to be taken into account. It is proposed to use modern numerical methods for this, i.e. the boundary element method (BEM) and the finite element method (FEM). The implementation of these methods is performed in the Matlab programming and modeling environment (BEM), and the FEM is used in the Ansys package. In accordance with the technologies of these methods, the design diagrams of the lower girders and the crane structure as a whole were formed. Exact models of strain of crane elements during transverse bending and constrained torsion are given. Calculations of the stressstrain state of the crane metal structures have been performed. On the basis of a preliminary field study, a numerical model is proposed for diagnosing the strength and stiffness characteristics of the carrier system of handling equipment using the BEM and FEM, which has never been used in the world. Conclusions are drawn about the influence of the thinning of the walls of metal structures on the values of normal and tangential stresses.
EN
The present article aims to describe the design of a fuzzy controller used for automated control of the thickness of the extruded polyethylene film effected by the adjustment of the actuator in the cooling ring. In order to determine whether the designed controller operates properly, a model extruder was created and a simulation study was carried out. The Simulink programming environment integrated with Matlab was used for the development of the fuzzy controller and the simulation. The conducted simulation study demonstrated that the implementation of the designed controller would enable the adjustment of thickness on the perimeter of the film tube and quick reaction to possible departure in the assumed film thickness in mass production.
EN
The paper presents the design of a fuzzy controller whose task is intelligent, linguistic rule based control of thickness of the extruded polyethylene film. The structure of the fuzzy controller was developed; then, its model was built in MATLAB SIMULINK program and simulations were run to verify its performance under laboratory conditions. Based on the investigation, it can be concluded that the developed controller enables precise adjustment of polyethylene film thickness, taking into account disturbances caused by internal and external factors.
EN
The paper presents the analysis of dynamic properties of pneumatic systems such as: cascade connection of membrane pressure transmitters and a pneumatic membrane actuator by means of differential equations of integer and non-integer order. The analyzed systems were described from the time perspective by means of step response, and in terms of frequency with the help of the Bode plot, i.e. logarithmic magnitude and phase responses. Each response was determined using differential equations of non-integer order. To determine the responses, the interactive Simulink package was an irreplaceable programming tool built on the basis of the MATLAB program, which enables the analysis and synthesis of continuous dynamic systems.
EN
The article presents the digital measuring elements of microprocessor protection, which use combined digital filters to determine the controlled signal during a time equal to a quarter of the period of fundamental frequency. The model of the proposed digital measuring body is implemented in the Matlab-Simulink system. Analysis of the results of computational experiments confirmed the correct functioning of the digital measuring element that had been proposed.
PL
W artykule przedstawiono cyfrowe elementy pomiarowe zabezpieczenia mikroprocesorowego, które wykorzystują połączone filtry cyfrowe do określania kontrolowanego sygnału w czasie równym jednej czwartej okresu częstotliwości podstawowej. Model proponowanego cyfrowego elementu pomiarowego jest zaimplementowany w systemie Matlab-Simulink. Analiza obliczeniowych wyników potwierdziła prawidłowe działanie zaproponowanego cyfrowego elementu pomiarowego.
first rewind previous Strona / 5 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.