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  • 1.
    Böhm, Annette
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Lidström, Kristoffer
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Jonsson, Magnus
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Larsson, Tony
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Evaluating CALM M5-based vehicle-to-vehicle communication in various road settings through field trials2010In: Proceedings - Conference on Local Computer Networks, LCN, (2010 12 01): 613-620, Piscataway, N.J.: IEEE Press, 2010, p. 613-620Conference paper (Refereed)
    Abstract [en]

    Future cooperative Intelligent Transport Systems (ITS) applications aimed to improve safety, efficiency and comfort on our roads put high demands on the underlying wireless communication system. To gain better understanding of the limitations of the 5.9 GHz frequency band and the set of communication protocols for medium range vehicle to vehicle (V2V) communication, a set of field trials with CALM M5 enabled prototypes has been conducted. This paper describes five different real vehicle traffic scenarios covering both urban and rural settings at varying vehicle speeds and under varying line-of-sight (LOS) conditions and discusses the connectivity (measured as Packet Reception Ratio) that could be achieved between the two test vehicles. Our measurements indicate a quite problematic LOS sensitivity that strongly influences the performance of V2V-based applications. We further discuss how the awareness of these context-based connectivity problems can be used to improve the design of possible future cooperative ITS safety applications.

  • 2.
    Carpatorea, Iulian
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Slawomir, Nowaczyk
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Rögnvaldsson, Thorsteinn
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Elmer, Marcus
    Volvo Group Trucks Technology, Göteborg, Sweden.
    Lodin, Johan
    Volvo Group Trucks Technology, Göteborg, Sweden.
    Learning of Aggregate Features for Comparing Drivers Based on Naturalistic Data2016In: Proceedings: 2016 15th IEEE International Conference on Machine Learning and Applications (ICMLA) / [ed] Lisa O’Conner, Los Alamitos, CA: IEEE Computer Society, 2016, p. 1067-1072Conference paper (Refereed)
    Abstract [en]

    Fuel used by heavy duty trucks is a major cost for logistics companies, and therefore improvements in this area are highly desired. Many of the factors that influence fuel consumption, such as the road type, vehicle configuration or external environment, are difficult to influence. One of the most under-explored ways to lower the costs is training and incentivizing drivers. However, today it is difficult to measure driver performance in a comprehensive way outside of controlled, experimental setting.

    This paper proposes a machine learning methodology for quantifying and qualifying driver performance, with respect to fuel consumption, that is suitable for naturalistic driving situations. The approach is a knowledge-based feature extraction technique, constructing a normalizing fuel consumption value denoted Fuel under Predefined Conditions (FPC), which captures the effect of factors that are relevant but are not measured directly.

    The FPC, together with information available from truck sensors, is then compared against the actual fuel used on a given road segment, quantifying the effects associated with driver behavior or other variables of interest. We show that raw fuel consumption is a biased measure of driver performance, being heavily influenced by other factors such as high load or adversary weather conditions, and that using FPC leads to more accurate results. In this paper we also show evaluation the proposed method using large-scale, real-world, naturalistic database of heavy-duty vehicle operation.

  • 3.
    Cederholm, Sebastian
    et al.
    Halmstad University, School of Business, Engineering and Science.
    Hussein Nizarki, Bafrin
    Halmstad University, School of Business, Engineering and Science.
    Elnätets kapacitet för framtida belastningar från elbilar: En känslighetsanalys på ett av Halmstads lokalnät2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The Swedish government have a vision that up untill 2050 Sweden’s transport system is going to be free of fossil fuels and to achieve this vision, electricity is going to be the main fuel and will play a decisive role in the future transportional market. As a result of this, HEM Nät AB is now interested in knowing how their local electrical grid will be affected by a larger amount of electric vehicles, EVs, charged through households. Along the local grid’s high voltage line there are nine substations, which provide power to 815 customers. A sensitivity analysis was conducted on the local grid to appreciate the available capacity for the future load of EVs. The analysis was based on four different gridparameters, which possibly can affect the set conditions of an electrical grid when an EV is being charged: voltage drop, transformer load, harmonics and dissymmetry. Different chargepowers and wirings have also been compared to see what roles they will have in the future. After the simulations and hand calculations all of the gridparameters exceeded the set conditions. This happened at different percentages of the households, which were charging their vehicles. The voltage drop and transformer load for both of the powers, 3,7 kW and 11 kW exceeded the limitations when 40 % respectively 20 % of the studied are was being loaded. Two scientific methods were used to appreciate the added current harmonics, where the first one regarded a reduction of the summarized value of the current harmonics, where the second did not. The results showed, that either of the methods would indicate a problem on the grid. The simulation of the dissymmetry, the limitation was met after 7 % more load was done under one and the same of the phases. Finally, the study concluded that the local grid is relatively strong and can hold 332 EVs with 3,7 kW and 161 EVs with 11 kW.

  • 4.
    Deutschmann, Oliver
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energy Science.
    Johansson, Thomas
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energy Science.
    Framtidens elbilar utmanar nutidens elnät: Påverkan av ett ökat antal elbilar på ett halländskt elnät2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The challenges facing low voltage grids are rising as an increasing number of domestic houses transition from fossil fueled heating to electricity based heating. Several environmental goals and visions have the same transition from fossil based power to electricity based power in mind for the transportation sector. One of the most important tools for this transformation is widely regarded to be the electric vehicle. With the demands of the electric vehicle pressuring the power grid, several questions arise regarding the growth of the electric vehicle market and what repercussions it may have on the grid. This paper focuses on a typical low voltage grid in southern Sweden and what effects a growing electric vehicle market may have on it. Through computer-assisted simulations based on several future scenarios regarding the EV market, this paper finds that few modifications and reinforcements are needed on this particular grid within the next 10 to 15 years. After this timeframe the voltage drop becomes a serious concern and should be addressed.

  • 5.
    Eriksson, Carl-Johan
    et al.
    Halmstad University, School of Business, Engineering and Science.
    Erlingsson, Jonas
    Halmstad University, School of Business, Engineering and Science.
    FRP i brokonstruktion: -varför används FRP inte i Sverige2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    FRP stands for Fiber Reinforced Polymer. FRP materials have yet to be introduced inbridge construction in Sweden. Composite materials can through combined componentsand manufacturing processes be tailored to fit advanced bridge designs. FRP materials arestrong, durable and of low weight. FRP materials give the superstructure reduced weightand are therefore a suitable alternative for industrial prefabrication. This report shows thatFRP materials are possible to use in bridge construction. With the introduction of a specificEurocode we are confident that FRP materials will become a competitive alternative inbridge construction in Sweden in the future.

  • 6.
    Johnsson, Mattias
    et al.
    Halmstad University, School of Business and Engineering (SET).
    Nilsson, Viktor
    Halmstad University, School of Business and Engineering (SET).
    Fel i produktionen: En studie om uppkomna fel i två anläggningsprojekt2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract

    The purpose of this study was to identify problems that may occur in the execution of a civil engineering project and suggest measures to reduce the risk of errors. The study was conducted in cooperation with a civil engineering company in the Gothenburg area. During two weeks in February 2012, a field study took place on two construction sites where disruption and problems that took more than 15 minutes to correct were noted. During the field study we identified 39 such occurrences in the projects and then these were classified into different categories according to their cause.

    The two largest categories were "Design" and "Planning", which accounted for half of the errors that were discovered.

    In the study results were evaluated to decide whether it was possible to detect discrepancies at an earlier stage. The cost to fix an error in the design stage may be significantly less than to correct the problem in production.

    According to the evaluation, 55% of the errors could have been detected earlier if there was a greater degree of observation for such issues by everyone involved in the project. The conclusion for this study was that there was potential to reduce time-consuming and costly errors occurring in production through an increased involvement from all involved in both investigated projects and improved communication between all those involved.

  • 7.
    Sporrong, Kristofer
    et al.
    Halmstad University, School of Business and Engineering (SET).
    Harrysson, Mattias
    Halmstad University, School of Business and Engineering (SET).
    Elektrisk integrering och projektering av förnybar energi i svagt lokalt elnät2012Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    To achieve a reliable and qualitative power conversion from the wind into electric power, a variety of factors and demands need to be obtained. Climatological and technological factors requires proper dimensioning and adjustment of the conversion technology, to harvest the greatest possible amount of energy and to be converted in a reliable and energy efficient way, that windmill owners, power grid owners require. The wind is as familiar an unpredictable power supply. The variations in intensity over time could mean a number of drive optimization problems with after-effects of the wind turbine, power grid and load. The consequences may depend on which type of technology that is installed in the different parts of the energy system. The area's power grid and varying power needs with characteristics over time, also has a significant importance. The turbulent wind gives deviations of voltage and power flow, especially in various extreme situations in weak power grids. Good interaction between the wind turbine and power grid with varying active and reactive power demand for the energy users, provides conditions for a good power quality and thus, an optimal and safe operation with few interruptions over time. It can be, and often is the mechanics, electro-technical choices in the wind turbine and associated electrical systems that play a critical role in how profitable installation is during the wind turbines technological life. The power grid owner strives for a good interaction between the power grid and electrical generation which rise for few faults between interruptions and errors. In the branch this is known as "Mean time between failures" MTBF. 

    According to the Swedenergy, harmonics, slow and fast voltage variations including required short-circuit power should be investigated and compared with those requirements and terms that prevails with electrical integration of power into the grid. The feasibility study has concluded two suitable power connection proposals including wind mapping research, later in this report it is described and suggested two related Smart Grid variants with energy storage for the two power connection proposals in the existing weak local grid. 

  • 8.
    Sporrong, Kristofer
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Ringvall, Angelica
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Pettersson, Per-Johan
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Smarta lokala energisystem, Vision-Teknik-Tillämpning2013Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The energy sector is facing an impending paradigm shift. Today’s technology enables the end-user to generate their own energy locally at home. Furthermore, recently developed storage technologies make it possible to balance energy demand with stored energy and integrate district heating with the local power grid. This means that in the future heat and electric power will interact and energy flows is converted over energy boundaries. This places high demands on the energy systems dynamic and adaptive functions as a whole. Distributed System Operator (DSO) will therefore need to transform the local energy system, which requires initial investment of energy technology and intelligent system solutions that are technically efficient, flexible, and economically viable.Halmstad Energi och Miljö (HEM) owns a local energy system that is well prepared to implement the vision of a sustainable energy system. The city of Halmstad has politically established that renewable energy will play a more crucial role in the future. A greater proportion of "locally-generated" renewable energy will be implemented in this reference system that includes about 60 000 inhabitants, a great number of different heating/cooling customers and 40,000 electricity customers.In the future, it will be required by HEM to integrate intelligent energy solutions, where energy consumers are increasingly micro generation and able to control their energy demand patterns according to the most economical forecast. The local energy system needs to be able to handle a larger share of intermittent electricity from solar, wind or hydropower that can automatically interact with thermal energy from biomass and waste in a flexible, efficient and economical manner. The project group therefore advice HEM to urgently take steps to reserve the rights to a future aggregator role within the municipality. For this to be possible, new business models and contracts are examined within the energy branch.This master thesis provides suggestions for an appropriate mix of energy that can be achieved by 2030 for the reference system. The proposed energy mix generates 20% of the electricity demand and 100% heat production (except peak load) locally from Renewable Energy Sources (RES) according to local political goals. It also provides suggestions for alternative technological configurations where electricity and district heating systems interact across system boundaries.

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