http://casopisi.junis.ni.ac.rs/index.php/FUElectEnerg/issue/feedFacta Universitatis, Series: Electronics and Energetics2019-10-17T10:51:55+02:00Prof. Ninoslav D. Stojadinovićfueaeed@junis.ni.ac.rsOpen Journal SystemsEditor-in-Chief: Ninoslav D. Stojadinović, Faculty of Electronic Engineering, University of Nis, Aleksandra Medvedeva 14, 18000 Nis, Serbia, E-mail: <a href="mailto:ninoslav.stojadinovic@elfak.ni.ac.rs">ninoslav.stojadinovic@elfak.ni.ac.rs</a>http://casopisi.junis.ni.ac.rs/index.php/FUElectEnerg/article/view/5412PARALLEL MATRIX MULTIPLICATION CIRCUITS FOR USE IN KALMAN FILTERING2019-10-17T08:29:05+02:00Rafal Dlugoszrafal.dlugosz@gmail.comKatarzyna Kubiakrafal.dlugosz@gmail.comTomasz Talaskarafal.dlugosz@gmail.comInga Zbierskarafal.dlugosz@gmail.com<p>In this work we propose several ways of the CMOS implementation of a circuit for the multiplication of matrices. We mainly focus on parallel and asynchronous solutions, however serial and mixed approaches are also discussed for the comparison. Practical applications are the motivation behind our investigations. They include fast Kalman filtering commonly used in automotive active safety functions, for example. In such filters, numerous time-consuming operations on matrices are performed. An additional problem is the growing amount of data to be processed. It results from the growing number of sensors in the vehicle as fully autonomous driving is developed. Software solutions may prove themselves to be insuffucient in the nearest future. That is why hardware coprocessors are in the area of our interests as they could take over some of the most time-consuming operations. The paper presents possible solutions, tailored to specific problems (sizes of multiplied matrices, number of bits in signals, etc.). The estimates of the performance made on the basis of selected simulation and measurement results show that multiplication of 3×3 matrices with data rate of <br />20 100 MSps is achievable in the CMOS 130 nm technology.</p>2019-10-14T11:01:44+02:00Copyright (c) 2019 Facta Universitatis, Series: Electronics and Energeticshttp://casopisi.junis.ni.ac.rs/index.php/FUElectEnerg/article/view/5743CONTROL OF SYSTEMS ON SPATIAL DOMAINS WITH MOVING BOUNDARIES: 3D PRINTING AND TRAFFIC2019-10-14T11:02:05+02:00Miroslav Krstićkrstic@ucsd.edu<em>Until roughly the year 2000, control algorithms (of the kind that can be physically implemented and provided guarantees of stability and performance) were mostly available only for systems modeled by ordinary differential equations. In other words, while controllers were available for finite-dimensional systems, such as robotic manipulators of vehicles, they were not available for systems like fluid flows. With the emergence of the “backstepping” approach, it became possible to design control laws for systems modeled by partial differential equations (PDEs), i.e., for infinite dimensional systems, and with inputs at the boundaries of spatial domains. But, until recently, such backstepping controllers for PDEs were available only for systems evolving on fixed spatial PDE domains, not for systems whose boundaries are also dynamical and move, such as in systems undergoing transition of phase of matter (like the solid-liquid transition, i.e., melting or crystallization). In this invited article we review new control designs for moving-boundary PDEs of both parabolic and hyperbolic types and illustrate them by applications, respectively, in additive manufacturing (3D printing) and freeway traffic.</em>2019-10-14T11:01:44+02:00Copyright (c) 2019 Facta Universitatis, Series: Electronics and Energeticshttp://casopisi.junis.ni.ac.rs/index.php/FUElectEnerg/article/view/4770DESIGNING METHOD FOR INTEGRATED BATTERY CHARGERS IN ELECTRICAL VEHICLES2019-10-14T11:02:05+02:00Aleksandar Milicmilic.aleksandar@etf.rsSlobodan Vukosavicboban@etf.rs<p><em>Electrical vehicles often make use of multi-phase induction motors. At the same time, the vehicles have an on-board charger, the power electronics device that converts the ac power from the mains and charges the traction battery. The traction inverter can be integrated with the charger, reducing in this way the component count, weight and cost, while the windings of the ac motor can be used as the inductors required to complete the charger topology, thus saving on passive components, iron and copper. The integrated charger performances depend on the configuration of the stator windings as well as on the topology of the power converter. The objective in charging mode is reaching a high efficiency while keeping the charging-mode electromagnetic torque at zero. In traction mode, the goals include the efficiency and the torque-per-Amps ratio. In order to compare and distinguish between the available topologies and configurations, the paper starts with the analysis of the magnetic field in the air-gap of the electric machine in both charging and traction modes. Based upon that, a novel algorithm is proposed which determines the space-time distribution of the air-gap field, eventually deriving all the relevant pulsating and revolving component of the magnetic field, thus providing the grounds for studying the losses, efficiency and torque pulsations in both charging and traction modes.</em></p>2019-10-14T11:01:44+02:00Copyright (c) 2019 Facta Universitatis, Series: Electronics and Energeticshttp://casopisi.junis.ni.ac.rs/index.php/FUElectEnerg/article/view/4805CLASSIFICATION OF ELECTRICITY CONSUMERS USING ARTIFICIAL NEURAL NETWORKS2019-10-14T11:02:05+02:00Dragana Milan Kneževićdknezevic28@gmail.comMarija Blagojevićdknezevic28@gmail.com<p class="Abstract">This paper explains the process of using neural networks, as one of numerous data mining techniques, for the classification of electricity consumers. The processed data comprised more than a million recordings of electricity consumption for 21,643 consumers over the period of four years and eight months. Using a data subset (70% of the entire dataset), the network was trained for the classification of consumers according to the type of the electric meter they possess (single-rate or dual-rate) and the zone they live in (city or village). The network input data in both cases included: consumer code, reading period from-to, current and previous meter reading for both low and high tariff, dual and single rate tariff consumption for that period and their total amount, as independent variables, whereas the network output comprised dependent variable classes (zone or type of electric meter). The results show that a network created in this way can be trained so well that it achieves high precision when evaluated using the test dataset. Using the available recordings about electricity consumption, the type of the electric meter consumers possess and the zone they live in can be predicted with the accuracy of 77% and 82%, respectively. These findings can provide the basis for further research using other data mining techniques.</p>2019-10-14T11:01:44+02:00Copyright (c) 2019 Facta Universitatis, Series: Electronics and Energeticshttp://casopisi.junis.ni.ac.rs/index.php/FUElectEnerg/article/view/4887ON THE NODE ORDERING OF PROGRESSIVE POLYNOMIAL APPROXIMATION FOR THE SENSOR LINEARIZATION2019-10-17T08:17:51+02:00Aneta Predrag Prijićaneta.prijic@elfak.ni.ac.rsAleksandar Ilićaca@elfak.rsZoran Dragoslav Prijićzoran.prijic@elfak.ni.ac.rsEmilija Živanovićemilija.zivanovic@elfak.ni.ac.rsBranislav Randjelovićbranislav.randjelovic@elfak.ni.ac.rs<p class="Abstract">Many sensors exhibit nonlinear dependence between their input and output variables and specific techniques are often applied for the linearization of their transfer characteristics. Some of them include additional analog circuits, while the others are based on different numerical procedures. One commonly used software solution is Progressive Polynomial Approximation. This method for sensor transfer function linearization shows strong dependence on the order of selected nodes in the linearization vector. There are several modifications of this method which enhance its effectiveness but require extensive computational time. This paper proposes the methodology that shows improvement over Progressive Polynomial Approximation without additional increase of complexity. It concerns the order of linearization nodes in linearization vector. The optimal order of nodes is determined on the basis of sensor transfer function concavity. The proposed methodology is compared to the previously reported methods on a set of analytical functions. It is then implemented in the temperature measurement system using a set of thermistors with negative temperature coefficients. It is shown that its implementation in the low-cost microcontrollers integrated into the nodes of reconfigurable sensor networks is justified.</p>2019-10-14T11:01:44+02:00Copyright (c) 2019 Facta Universitatis, Series: Electronics and Energeticshttp://casopisi.junis.ni.ac.rs/index.php/FUElectEnerg/article/view/4936THE INFLUENCE OF CONDUCTIVE PASSIVE PARTS ON THE MAGNETIC FLUX DENSITY PRODUCED BY OVERHEAD POWER LINES2019-10-14T11:02:05+02:00Slavko Vujevićvujevic@fesb.hrTonći Modrićtmodric@fesb.hrThere has been apprehension about the possible adverse health effects resulting from exposure to power frequency magnetic field, especially in the overhead power lines vicinity. Research work on the biological effects of magnetic field has been substantial in recent decades. Various international regulations and safety guidelines, aimed at the protection of human beings, have been issued. Numerous measurements are performed and different numerical algorithms for computation of the magnetic field, based on the Biot-Savart law, are developed. In this paper, a previously developed 3D quasistatic numerical algorithm for computation of the magnetic field (i.e. magnetic flux density) produced by overhead power lines has been improved in such a way that cylindrical segments of passive conductors are also taken into account. These segments of passive conductors form the conductive passive contours, which can be natural or equivalent, and they substitute conductive passive parts of the overhead power lines and towers. Although, their influence on the magnetic flux density distribution and on the total effective values of magnetic flux density is small, it is quantified in a numerical example, based on a theoretical background that was developed and presented in this paper.2019-10-14T11:01:44+02:00Copyright (c) 2019 Facta Universitatis, Series: Electronics and Energeticshttp://casopisi.junis.ni.ac.rs/index.php/FUElectEnerg/article/view/4950COMPACT LEFT-HANDED DUAL-BAND FILTERS BASED ON SHUNDTED STUB RESONATORS2019-10-14T11:02:05+02:00Vasa Radonicvasarad@uns.ac.rsVesna Crnojevic-Benginbengin@uns.ac.rs<p class="Abstract">In this paper, super-compact microstrip dual-band resonator is presented, designed using the superposition of two simple left-handed (LH) resonators with single shunt stub. The proposed resonator exhibits spurious response in wide frequency range and therefore allows construction of dual-band filters using the superposition principle. The equivalent circuit model of the proposed resonator is crated and the influence of different geometrical parameters to the performances of the resonator are analyzed in details. As an examples, two dual-band filters that operate simultaneously at the WiMAX frequency bands are designed.</p>2019-10-14T11:01:44+02:00Copyright (c) 2019 Facta Universitatis, Series: Electronics and Energeticshttp://casopisi.junis.ni.ac.rs/index.php/FUElectEnerg/article/view/5006THE USAGE OF LAMBERT W FUNCTION FOR IDENTIFICATION AND SPEED CONTROL OF A DC MOTOR2019-10-14T11:02:05+02:00Radmila Gerovgerov@ptt.rsZoran Jovanovićzoran.jovanovic@elfak.ni.ac.rs<p class="Abstract">The paper proposes a new method of identifying the linear model of a DC motor. The parameter estimation is based on the closed-loop step response of the DC motor under a proportional controller. For the application of the method, a deliberate delay of the measured speed was introduced. The paper considers the speed regulation of the direct current motor with negligible inductance by applying 1-DOF and 2-DOF, proportional integral retarded controllers. The proportional and integral gain of the PI retarded controllers was received by using a pole placement method on the identified model. The Lambert W function was applied for the identification and in designing the controller with the purpose of finding the rightmost poles of the closed-loop as well as the boundary conditions for selecting the gain of the PI controller. The robustness of the calculated controllers was considered under the effect of an disturbance, uncertainty in each of the DC motor parameters as well as perturbations in time delay.</p>2019-10-14T11:01:44+02:00Copyright (c) 2019 Facta Universitatis, Series: Electronics and Energeticshttp://casopisi.junis.ni.ac.rs/index.php/FUElectEnerg/article/view/5081NOVEL SINGLE LAYER FAULT TOLERANCE RCA CONSTRUCTION FOR QCA TECHNOLOGY2019-10-14T11:02:05+02:00Zahra Taherisztaheri20@gmail.comAbdalhossein Rezairezaie@acecr.ac.irHamid Rashidiha.rashidi20@gmail.com<p><em>Quantum-dot Cellular Automata (QCA) technology has become a promising and accessible candidate that can be used for digital circuits implementation at Nanoscale, but the circuit design in the QCA technology has been limited due to fabrication high-defect rate. So, this issue is an interesting research topic in the QCA circuits design. In this study, a novel 3-input Fault Tolerance (FT) Majority Gate (MG) is developed. Accordingly, an efficient 1-bit QCA full adder is developed using the developed 3-input MG. Then, a new 4-bit FT QCA Ripple Carry Adder (RCA) is developed based on the proposed 1-bit FT QCA FA. The developed circuits are implemented in the QCADesigner tool version 2.0.3. The results indicate that the developed QCA circuits provide advantages compared to other QCA circuits in terms of</em> <em>double and single cell missing defect, area and delay time.</em></p>2019-10-14T11:01:44+02:00Copyright (c) 2019 Facta Universitatis, Series: Electronics and Energeticshttp://casopisi.junis.ni.ac.rs/index.php/FUElectEnerg/article/view/5221DEVELOPMENT OF AN AUTOMATED GAS-LEAKAGE MONITORING SYSTEM WITH FEEDBACK AND FEEDFORWARD CONTROL BY UTILIZING IOT2019-10-17T10:51:55+02:00Mhia Md. Zaglul Shahadatmhiashahadat@gmail.comAvijit Mallikavijitme13@gmail.comMd. Monowarul Islammonowarulislamahsan27@gmail.com<p>Liquefied Petroleum Gas (LPG) is used in many ranges of applications like home and industrial appliances, in vehicles and as a propellant and refrigerator. However, leakage of LPG produces hazardous and toxic impact on human begins and other living creatures. There by, the authors developed a system to monitor the LPG gas leakage and make alert to users of it. In this research, MQ-6 gas sensor is used for sensing the level of gas concentration of a closed volume; and to monitor the consequences of environmental changes an IoT platform has been introduced. Robust control along with cloud based manual control has been applied so that the gas leakage can be prevented in the response of either feedback or feedforward commands individually. It switches on the specified relays to control the level of gas concentration in the time of leakage the excess gas in times of leakage. It rechecks the value again and again if it crosses 300 ppm it will setup a relay-based switching on control mechanism using Thingspeak cloud. The controller used here is Node-MCU v:1.0. This research provides design approach on both software and hardware. Hence an embedded system comprising of Relay switches, Embedded C<sup>++</sup>, Gas sensor, Temperature & Humidity sensor along with Internet of Things (IoT) is fabricated to meet the objectives of the current research.</p>2019-10-14T11:01:44+02:00Copyright (c) 2019 Facta Universitatis, Series: Electronics and Energetics