Elektroteknik (E2) // Electrical Engineering (E2)

Använd denna länk för att länka till samlingen:

https://odr.chalmers.se/handle/20.500.12380/12

Arbetar med hållbara och smarta lösningar på samhällsutmaningar, såsom energieffektivitet och elektrifiering inom områden från transport- och produktionssystem till kommunikationslösningar och medicinteknik.

Läs mer om våra utbildningar

För forskning och forskningspublikationer, se https://research.chalmers.se/organisation/elektroteknik/

At the department of Electrical Engineering research and education are performed in the areas of Communication and Antenna systems, Systems and Control, Signal processing and Biomedical engineering, and Electric Power Engineering.

We work with challenges for a sustainable future in society of today, for example in the growing demands concerning efficient systems for communications and electrification. Our knowledge is of use everywhere where there is advanced technology with integrated electronics, no matter if it involves electricity, electrical signals, optical signals or microwaves.

Studying at the Department of Electrical Engineering at Chalmers

For research and research output, please visit https://research.chalmers.se/en/organization/electrical-engineering/

Browse

Visar 1 - 20 av 2777

Förutsäga tillgänglighet och pris för snabbladdning av elektriska personbilar/ Availability and price for electric vehicle fast charging
Lindbom, Olle; Zavol Deylami, Diana; Kula, Lech Kazimierz; Lüning, Algot; Jonasson, Eskil; Keyhanfar, Nickie; Chalmers tekniska högskola / Institutionen för elektroteknik; Chalmers University of Technology / Department of Electrical Engineering; Ehnberg, Jimmy; Grauers, Anders
Abstract This thesis addresses the increasingly critical issue of the availability and pricing of fast charging stations for electric vehicles. With the rise in electric vehicle usage, the demand for efficient and rapid charging solutions has become paramount. The study utilizes agent-based modeling techniques to simulate the behavior of electric vehicle charging systems under varying conditions of supply and demand. The aim is to provide a nuanced understanding of how different variables such as queuing times, station availability, charging speed, and pricing strategies impact user experience and profits. The simulation models queue formation and waiting times at fast charging stations, offering insights into potential bottlenecks. The research also evaluates the economic viability of various charging infrastructures and explores the balance between charging costs and accessibility. It is worth noting that this thesis only considers one type of electric vehicle and assumes a static electricity price. Key findings indicate that future electric vehicle drivers will have access to fast chargers with prices reflecting current levels. An increased number of chargers exponentially reduces waiting times and decreases the variability of waiting times. A linear increase in the number of chargers is necessary to meet the growing demand. Market research indicated that many drivers prioritize charging speed over lower prices. In comparison, fast-chargers with maximum 250 kW power economically outperform 150 kW fast-chargers, therefore 250 kW chargers are preferred on highways with consistent traffic. Besides, lowering prices during periods of low demand increase profits.
Human centric virtual driven product development - Using FE simulation to compare passive versus active muscle activity for human body model development
Tjernberg, Sigrid; Chalmers tekniska högskola / Institutionen för elektroteknik; Fhager, Andreas; Mendoza Vazquez, Manuel
Abstract The aim of this thesis was to gather information about active and passive muscle tissue around the pelvis and use it to simulate the effect on a human body model (HBM). A literature review was conducted in order to find muscle tissue parameters that could be used in the simulation of muscles around the pelvis. Three studies were chosen to compare muscle tissue parameters, the last of which included muscle tissue parameters for both passive and active muscle tissue. The literature review was also conducted to investigate the effects of body mass index (BMI) on the muscle tissue properties. Then two models were designed in order to simulate in vivo and in vitro muscle tissue tests which were used for the first sets of simulations. The first simulations were designed to be done quickly so that several different muscle tissue parameters could be tested effectively and compared. Part of this comparison was to check the material model stability in the range of relevant strains. The last step was to implement the muscle tissue parameters in a HBM and see how it affected the model. The results showed that there is a lack of information within the field and a lot of misinformation where bad values were being used, however a few studies which were deemed as good which had parameters which could be used in ABAQUS FEA were summarized in this thesis. All these muscle tissue parameters were tested on the cylinder designs which resulted in force-displacement plots which could be compared to each other. Active and passive muscle material parameters were then applied to a HBM which resulted in two different models which were compared. The conclusion of the thesis showed that active versus passive tissue does affect the HBM.
Live Analysis of Mesh Networks
Gattelu, Ashutosh Mahesh; Chalmers tekniska högskola / Institutionen för elektroteknik; Svensson, Tommy; Säfstorm, Robin; Aliakbari, Javad
Abstract In the realm of the Internet of Things (IoT), the complexity of mesh architectures, particularly those employing rebroadcasting(RBC) mesh, presents formidable challenges. These challenges, ranging from flooding of packets due to rebroadcast, congestion, packet loss, demand innovative solutions to ensure the seamless operation of interconnected devices. This study embarks on a journey to unravel the intricacies of IoT mesh networks, employing a multidimensional approach that blends cutting-edge visualization techniques with sophisticated monitoring tool. This study presents a Python-based application that has been painstakingly designed to make real-time IoT mesh network monitoring and analysis easier. The study provides thorough time series visualization by utilizing the powerful features of InfluxDB and Grafana, illuminating the dynamic interactions between devices in the network. Through an elaborate test setup simulating diverse household scenarios with over 200 interconnected devices, the research meticulously examines the efficacy of live analysis in unraveling the complexities of mesh networks. Parameters such as packet count, system time synchronization, version cache integrity, level validation, and scene validations are meticulously scrutinized in real-time, providing profound insights into the network’s behavior. The findings underscore the superiority of live monitoring in detecting nuanced outcomes and ensuring real-time validation of network performance. This thesis not only contributes to advancing smart home technology evaluation but also offers practical insights into the implementation and analysis of IoT mesh networks. Through this work, we aim to enhance the reliability and efficiency of Plejd’s smart home solutions, ultimately contributing to the broader field of IoT network research.
Hierarchical Optimization for Charge Planning and Thermal Management of Battery Electric Trucks
Borghed, Isac; Chalmers tekniska högskola / Institutionen för elektroteknik; Murgovcki, Nikolce; Lindgärde, Olof; Suman, Saurabh
Abstract To meet the climate goals set by the UN and the EU the shift from vehicles driven by fossil fuels to zero- and low-emission vehicles (ZLEV) needs to be accelerated. One such focus area is the adoption of battery-electric vehicles (BEVs). At the moment, electric trucks suffer from a range disadvantage compared to internal combustion engine (ICE) trucks, and since the recharging times are long the optimal planning of charging becomes a complex logistical problem. In this thesis the problem of optimal charge planning and thermal management for a specific route and speed profile is studied, where the objective of the optimization is to minimize the total cost of operation (TCOP), taking into consideration stochastic uncertainties such as traffic speed and charging station queuing times. The optimization problem is formulated as a mixed-integer nonlinear programming (MINLP) problem, which is solved by decomposing the problem into two layers. The top layer is solved using stochastic dynamic programming (SDP) for a simplified version of the MINLP. The charging decisions found using SDP are sent to the lower layer which can then be formulated as a nonlinear programming (NLP) problem which is solved using the FORCESPRO NLP solver using a more comprehensive model of the truck’s dynamics. The mission planner is evaluated on a 460 km route and a 660 km route, with both including recharging stations. It is found that the hierarchical mission manager reduces costs by up to 7.8% compared to a previously developed mission manager which simplified the MINLP to an NLP using a sigmoid activation function to represent charging decisions. The hierarchical solver has also been found to improve the solution’s robustness and can consider time-varying disturbances such as traffic speed and charging prices.
Aperture Efficiency of an Array Fed Truncated Cassegrain Reflector Antenna
Henkow, Victor; Chalmers tekniska högskola / Institutionen för elektroteknik; Yang, Jian; Schäfer, Thomas
Abstract If a reflector antenna needs to be mechanically steered, it can sometimes be necessary to truncate the sides of the main reflector to keep it from hitting the structure behind it. If the feed is kept circularly symmetric when the main reflector is truncated, it will lead to a low aperture efficiency. In this report a truncated Cassegrain reflector antenna was studied. The purpose was to investigate if the aperture efficiency could be improved by feeding the antenna with a two element horn array instead of a single horn. This was done by doing simulations in CST Studio Suite and optimizing using a Python script. Both types of feeds were modeled with the same limitations, so that the single horn antenna could act as a control. To improve the simulation time, the whole antenna was not optimized, instead the aperture efficiency was calculated from the feed using the spillover efficiency, the polarization efficiency, the illumination efficiency and the phase efficiency. The best single horn feed design had an aperture efficiency of 41%, and the best array feed design had an aperture efficiency of 49%. This indicates that the array feed is more efficient. However, the design that was tested was only a proof of concept, ignoring other efficiencies. The conclusion is that the concept shows potential, but more research needs be done before any conclusions about a realizable design can be made.
3D Pose Estimation of Football Players
Osterman, Joakim; Sjögren, Olof; Chalmers tekniska högskola / Institutionen för elektroteknik; Svensson, Lennart; Sjöberg, Anders
Abstract In the context of football analytics, video recordings of matches play a crucial role in post-game analysis. However, videos are inherently limited because they only allow viewers to follow the match from the camera’s perspective. This thesis is part of a larger project aimed at creating 3D representations of football matches from video, thus enabling users to view the game from anywhere inside the virtual 3D environment. The larger project consists of three parts. This thesis focuses on estimating the camera parameters, as well as the 3D poses and locations of the players in the video. The other two projects focus on player tracking and player texture generation. A pipeline consisting of camera calibration and pose estimation is proposed, taking video recordings and bounding box annotations as input and predicting camera pa rameters as well as the players’ 3D poses and locations. For camera calibration, a model specifically tailored for cameras viewing football fields is used. The results indicate accurately predicted positions and viewing angles for the estimated camera. Pose estimation is performed using a pre-trained model and results in visually ac curate projections, although perspective ambiguities are present when the 3D poses are viewed from different angles. The main approach for positioning players was to detect when players touched the ground and interpolate the positions for ambigu ous frames. The results are promising, but noise in the depth estimations occurs due to perspective ambiguities. Subsequently, an optional optimization of poses and positions using multi-view triangulation is also presented, showing possibilities for further refinement to ensure realistic and consistent human poses. Future work on pose and location optimization could yield a pseudo-truth dataset for further enhancements to improve overall poses and positions from strictly monocular video.
Design av transportbehållare för sjöräddningsdrönare
Persson, Samuel; Ranbring, Ted; Chalmers tekniska högskola / Institutionen för elektroteknik; Chalmers University of Technology / Department of Electrical Engineering; Thomas, Bertil; Falkman, Fredrik
Sammanfattning I dagsläget tar en utryckning av svenska sjöräddningssällskapet från land till olycksplats i genomsnitt 40 minuter. För att förbättra hantering av situationer har Sjöräddningssällskapet utvecklat en fixed-wing drönare som på 10 minuter kan ta sig till olycksplatsen och skicka bilder som kan analyseras av räddningspersonal. Därför undersöks nu möjligheten att bestycka drönare med gods som kan underlätta vid räddningar. Examensarbetet vid Svenska Sjöräddningssällskapet går ut på att utveckla en behållare som kan vinschas ner från en fixed-wing drönare. Behållaren är utvecklad för att möjliggöra transport av föremål ut till havs, vid larm kan den lastas med uppdragsspecifikt gods och flyga till destinationen. Inledningsvis utfördes en marknadsundersökning för att få en bättre förståelse för vilka befintliga lösningar och idéer som redan finns på marknaden. Utifrån detta framställdes det ett flertal olika koncept som sedan eliminerades till ett koncept kvarstod, vilket sedan realiserades och vidareutvecklades. Resultatet av detta arbete var en fungerande prototyp för behållarstabilisering med drönare. Genom fortsatt arbete, omfattande tester och implementering med drönare finns potentialen att uppnå målet att effektivisera räddningsinsatser till havs. Denna framstegsmöjlighet öppnar upp för innovation och teknologi kan bidra avsevärt till att öka säkerheten och effektiviteten vid räddningsinsatser till sjöss.
Measurements and Models for Direction of Arrival of Radio Waves in LOS in Urban Microcells
(2000) Chen, Ming; Chalmers tekniska högskola / Institutionen för signaler och system; Chalmers University of Technology / Department of Signals and Systems
Wideband (5MHz) measurements have been performed at 1900 MHz in a typical urban microcell using a synthetic Uniform Linear Array (ULA) at the base station. The Direction of Arrival (DOA) of the received signal is investigated using an Iterative Maximum Likelihood algorithm (IML). A 3-Ray DOA model is proposed to give the basic DOA angular spread profile with a modest T-R distance. A hypothesis of virtual Multiray DOA model is proposed to model the measurements for LOS case. The parameters sensitivity of constitutive parameter of different material, street width, MS position and base station antenna height of the virtual Multiray DOA model is investigated.
Application of IEEE 802.1X in HiperLAN type 2 Chalmers
(2001) Kelati, Amleset; Chalmers tekniska högskola / Institutionen för elektroteknik; Svensson, Arne
The research within Information Technology has been subject to a tremendous speed-up in the latest years, mainly due to the reduced prices of the related technology and, consequently, to a strongly increased interest of the users. This causes a positive feedback loop, since many companies decide to invest more money in such area, reducing further the prices and accelerating this process. One of the major issues in this big race has been the concept “Be connected always and everywhere”, which translated in an increased development of public networks on one side and in a further growth of big corporation networks on the other side. The common factors of these big areas are mobility, which implies wireless networks, and availability of services, which also means access to more or less important information. Increased size, mobility and availability of services on networks that become bigger and bigger increases tremendously the importance of data-security. Trust, authentication, and authorization have become vital key words within the design of big, mobile networks. IEEE 802.1X, also known as “Port Based Network Access Control” is a means for providing authentication and authorization for big networks that offer the possibility to many devices to attach to them, making their services available. This master thesis work, carried out at Ericsson Enterprise AB, Wireless LAN Systems in Sundbyberg (Sweden), had as a primary objective to study the authentication and authorization standard IEEE 802.1X (Draft version 11, released March 27th 2001) and its integration in HIPERLAN type 2 (HIPERLAN/2), which is a standard for wireless LAN. The project has been accomplished for the Department of Signals and Systems at the Chalmers University of Technology in Göteborg, Sweden. The goals of the thesis work were to analyze the current version of the standards and other related protocols in order to gain competence in the area of the study how IEEE 802.1x could be integrated in HIPERLAN/2 based network. In this work we propose a solution for the implementations problem and design, develop and test a basic prototype. The result shows that IEEE 802.1x can be deployed within a wireless network based on HIPERLAN/2 by adapting certain features of the two standards and by adopting certain rationale while developing an architecture based on them. This report is structured in such a way to mirror the different goals of the thesis. Part 1: Contains a description of the current version of the standard and of other related protocols that collaborate and participate in enhancing security in a typical LAN environment. Part 2: Illustrates the methodology that has been used and the achieved results in order to integrate IEEE 802.1X and an HIPERLAN/2-based network. Part 3: Describes roughly the implementation of the prototype, its limitations and further work to make it usable in a professional and non-experimental environment; furthermore, it describes the result of the testing operation. Part 4: Concludes the report by summarizing the whole work, by illustrating the achieved results and by giving some suggestions for a follow-up of this thesis work.
Modello per la stima di coppia nei motori diesel
(2003) Falcone, Paolo; Chalmers tekniska högskola / Institutionen för signaler och system; Chalmers University of Technology / Department of Signals and Systems
Low Order Approximations of Continuously Stirred Biofilm Reactors with Monod Kinetics
(2004) Göransson, Elin; Chalmers tekniska högskola / Institutionen för signaler och system; Chalmers University of Technology / Department of Signals and Systems
Design of controllers and optimization of plants using biofilm reactors often require dynamic models and efficient methods of simulation. Continuously stirred biofilm reactors (CSBRs) are useful model units in modeling of a variety of different biofilm reactors. Often the reaction kinetics in the biofilm is described by a Monod expression. Using standard modeling assumptions the equations describing the fast dynamics of a CSBR will then, for each substrate, be one nonlinear partial differential equation coupled with one linear ordinary differential equation. Here it is shown how a few nonlinear ordinary differential equations, which may be solved with standard integration methods, can be used as a close approximation. The approximations are derived using two common MWR methods, the Galerkin method and the orthogonal collocation method. Uniqueness and convergence properties are discussed. The stationary approximations can either be used as they are or to generate initial values for iterative methods to find solutions to more complicated models used, for example, in studies of the long term dynamics. Simulations of steps, impulses and random input responses using the approximations are compared to high accuracy simulations using the finite element method. The simulations show that a second order state space model is enough to describe the system for biofilms and reactors with low reaction rates and where the bulk volume is large compared to the liquid volume in the biofilm. A sixth order approximation, with a maximum error of 0.5%, should however be sufficient in almost all applications. The orthogonal collocation method turns out to have some advantages compared to the Galerkin method. It is easy to expand to higher orders, the errors are somewhat smaller, and the model expressions are simpler. Further, it is investigated how a liquid boundary layer on the biofilm surface affects the accuracy of the approximations. Simulations imply that the errors, compared to the FEM simulations, are smaller when this boundary layer is considered in the model. Finally, a collocation method where the collocation points are not chosen to be roots of orthogonal polynomials is shown to be less accurate than the standard orthogonal collocation method, where the collocation points are the roots of Legendre polynomials.
Design and Development of Tracking Antennas
(2005) Franzén, Magnus; Chalmers tekniska högskola / Institutionen för signaler och system; Chalmers University of Technology / Department of Signals and Systems
Characterization of Omni-Directional Antennas Using H-Near Field Probe
(2005) Turlapaty, Anish Chand; Chalmers tekniska högskola / Institutionen för signaler och system; Chalmers University of Technology / Department of Signals and Systems
Characterization of Reverberation Chamber for Measurements of UWB Antennas
(2005) Quevedo Teruel, Oscar; Chalmers tekniska högskola / Institutionen för signaler och system; Chalmers University of Technology / Department of Signals and Systems
Análisis y Evaluación del Throughput Máximo en Sistemas de Transmisión con Modulación y Codificación utilizando el Límite de Gallager
(2005) Alvarado, Alex; Chalmers tekniska högskola / Institutionen för signaler och system; Chalmers University of Technology / Department of Signals and Systems
TCP Measurements of GSM & 3G Phones in Reverberation Chamber at GSM 900/GSM 1800 MHz and 3G Frequency Bands
(2005) Özcan, Sadullah; Chalmers tekniska högskola / Institutionen för signaler och system; Chalmers University of Technology / Department of Signals and Systems
Experimental Studies of Operating Near-Field Antennas
(2005) Björkström, Jessica; Chalmers tekniska högskola / Institutionen för signaler och system; Chalmers University of Technology / Department of Signals and Systems
SANTANA - Smart Antenna Terminal Design
(2005) Ying, Liu; Chalmers tekniska högskola / Institutionen för signaler och system; Chalmers University of Technology / Department of Signals and Systems
Analysis of multispectral reconnaissance imagary for target detection and operator support
(2006) Brattberg, Oskar; Chalmers tekniska högskola / Institutionen för signaler och system; Chalmers University of Technology / Department of Signals and Systems
Integration of CAPSim-propulsion models in the Chalmers Vehicle Simulator
(2006) Schedel, Felix; Chalmers tekniska högskola / Institutionen för signaler och system; Chalmers University of Technology / Department of Signals and Systems

Browse

Browsar Elektroteknik (E2) // Electrical Engineering (E2) efter Publicerad

Sökresultat per sida

Sortera efter