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  • 201.
    De Backer, Jeroen
    et al.
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Bolmsjö, Gunnar
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Thermoelectric method for temperature measurement in friction stir welding2013In: Science and technology of welding and joining, ISSN 1362-1718, E-ISSN 1743-2936, Vol. 18, no 7, p. 541-550Article in journal (Refereed)
    Abstract [en]

    Previous research within friction stir welding (FSW) has demonstrated that online control of welding parameters can improve the mechanical properties and is necessary for certain applications to guarantee a consistent weld quality. One approach to control the process is by adapting the heat input to maintain a stable welding temperature, within the specified operating boundaries. This requires accurate in-process temperature measurements. This paper presents a novel method to measure the temperature at the interface of the FSW tool and workpiece. The method is based on the thermoelectric effect between dissimilar materials. The measurements are compared to thermocouple measurements and to a physical model and show good correspondence to each other. Experiments demonstrate that the method can quickly detect temperature variations, due to geometrical variations of the workpiece or due to parameter changes. This allows use of the method for online control of robotic FSW.

  • 202.
    De Backer, Jeroen
    et al.
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Bolmsjö, Gunnar
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Christiansson, Anna-Karin
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Temperature control of robotic friction stir welding using the thermoelectric effect2014In: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 70, no 1-4, p. 375-383Article in journal (Refereed)
    Abstract [en]

    Friction stir welding (FSW) of non-linear joints receives an increasing interest from several industrial sectors like automotive, urban transport and aerospace. A force-controlled robot is particularly suitable for welding complex geometries in lightweight alloys. However, complex geometries including three-dimensional joints, non-constant thicknesses and heat sinks such as clamps cause varying heat dissipation in the welded product. This will lead to changes in the process temperature and hence an unstable FSW process with varying mechanical properties. Furthermore, overheating can lead to a meltdown, causing the tool to sink down into the workpiece. This paper describes a temperature controller that modifies the spindle speed to maintain a constant welding temperature. A newly developed temperature measurement method is used which is able to measure the average tool temperature without the need for thermocouples inside the tool. The method is used to control both the plunging and welding operation. The developments presented here are applied to a robotic FSW system and can be directly implemented in a production setting.

  • 203.
    De Backer, Jeroen
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Christiansson, Anna-Karin
    University West, Department of Engineering Science, Division of Automation Systems.
    Surface Quality and Strength in Robotic Friction Stir Welding of Thin Automotive Aluminium Alloys2011In: The 4th International Swedish Production Symposium / [ed] Jan-Eric Ståhl, The Swedish Production Academy , 2011, p. 554-562Conference paper (Refereed)
    Abstract [en]

    Friction Stir Welding (FSW) is a novel method for joining materials without using consumablesand without melting the materials. It uses a rotating tool that creates frictionalheat and mixes the materials mechanically together. Robotic application of FSW allowsthree-dimensional welding of light-weight metals in e.g. the automotive industry. TheStiRoLight project is driven by Saab Automobile AB and performed at University Westfor investigation of robotic FSW of three-dimensional welding seams. It aims to introduceFSW in the automotive production line. This paper describes the effect of penetrationdepth of the FSW tool during force controlled robotic welding of thin (< 2 mm) aluminium inoverlap configuration. The influence of pin length on strength of welded aluminium sheetsis investigated using tensile and peel tests. The main limiting factor for penetration depthis the surface quality on the backside of the weld, which often is important in automotiveapplications. Further, the roughness of the plates on the backside is measured and relatedto pin length and backing bar properties. This paper shows a relation between penetrationdepth and tensile strength, and suggests an optimal pin length to guarantee a good weldquality while maintaining an acceptable surface quality. The influence of sheet thicknesstolerance is also discussed. Knowledge is fed back to designers and manufacturingengineers to facilitate for use in production with guaranteed product quality.

  • 204.
    De Backer, Jeroen
    et al.
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Christiansson, Anna-Karin
    University West, Department of Engineering Science, Division of Process and Product Development.
    Oqueka, Jens
    University West, Department of Engineering Science.
    Bolmsjö, Gunnar
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Investigation of path compensation methods for robotic friction stir welding2012In: Industrial robot, ISSN 0143-991X, E-ISSN 1758-5791, Vol. 39, no 6, p. 601-608Article in journal (Refereed)
    Abstract [en]

    Purpose – Friction stir welding (FSW) is a novel method for joining materials without using consumables and without melting the materials. The purpose of this paper is to present the state of the art in robotic FSW and outline important steps for its implementation in industry and specifically the automotive industry.

    Design/methodology/approach – This study focuses on the robot deflections during FSW, by relating process forces to the deviations from the programmed robot path and to the strength of the obtained joint. A robot adapted for the FSW process has been used in the experimental study. Two sensor-based methods are implemented to determine path deviations during test runs and the resulting welds were examined with respect to tensile strength and path deviation.

    Findings – It can be concluded that deflections must be compensated for in high strengths alloys. Several strategies can be applied including online sensing or compensation of the deflection in the robot program. The welding process was proven to be insensitive for small deviations and the presented path compensation methods are sufficient to obtain a strong and defect-free welding joint.

    Originality/value – This paper demonstrates the effect of FSW process forces on the robot, which is not found in literature. This is expected to contribute to the use of robots for FSW. The experiments were performed in a demonstrator facility which clearly showed the possibility of applying robotic FSW as a flexible industrial manufacturing process.

  • 205.
    De Backer, Jeroen
    et al.
    University West, Department of Engineering Science, Division of Production System. TWI Ltd, Cambridge, UK.
    Martin, Jonathan
    TWI Ltd, Cambridge, UK.
    Wei, Sam
    TWI Ltd, Cambridge, UK.
    Robotic Stationary Shoulder FSW: benefits and limitations2016In: Conference proceedings of the 11th International Symposium on Friction Stir Welding, 2016Conference paper (Refereed)
  • 206.
    De Backer, Jeroen
    et al.
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Soron, Mikael
    ESAB Welding AB .
    Three-dimensional friction stir welding of Iconel 718 using the ESAB Rosio FSW-robot2013In: Trends in Welding Research: Proceedings of the International Conference on Trends in Welding Research, June 4-8, 2012, Hilton Chicago/Indian Lakes ResortChicago, Illinois, USA / [ed] Tarasankar DebRoy, Stan A. David, John N. DuPont, Toshihiko Koseki, Harry K. Bhadeshia, Ohio: ASM International, 2013, p. 829-833Conference paper (Refereed)
    Abstract [en]

    Robotic Friction Stir Welding (FSW) facilitates for increased welding flexibility, and allows for studies of forces in three dimensions without having the high cost of a stiff 5-axes FSW machine. Recent developments in tool materials and welding equipment motivate this study on FSW of high-strength alloys by a robot in a three dimensional workspace. New concepts of aircraft engines suggest higher temperatures to increase engine efficiency, requiring more durable materials such as the nickel-based alloy 718. The ESAB Rosio (TM) FSW robot, used in this study, can deliver up to 15kN downforce and 90Nm torque. This is sufficient for welding high-strength alloys of limited thickness. This study focuses on the process forces during friction stir welding of Inconel 718 with thickness up to 3mm in butt-joint configuration. A newly developed threaded Poly-Crystalline Boron Nitride (PCBN) tool with convex shoulder is used in a local argon-shielded atmosphere. Initial tests are performed in a stiff FSW machine in position controlled mode. The measured process forces in position control are later on used as parameters on the force-controlled robot. Different backing bar materials are investigated with the aim to decrease the risk of root defects. Tool steel and regular inconel backing bars are proven to be too soft for this purpose and alternatives are suggested. The optimal welding parameters are tuned to combine a good weld quality with the process forces that can be obtained by the robot. Preheating is used to further decrease the need of high process forces.

  • 207.
    De Backer, Jeroen
    et al.
    University West, Department of Engineering Science, Division of Electrical and Automation Engineering.
    Soron, Mikael
    ESAB Welding AB .
    Cederqvist, Lars
    Influence of side-tilt angle on process forces and lap joint strength in robotic friction stir welding2012In: Proceedings 9th International friction stir welding symposium, Huntsville, AL, USA, 15th to 17th of May 2012, 2012, p. CD-Conference paper (Refereed)
  • 208.
    de Blanche, Andreas
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering. Institutionen för data- och informationsteknik, Datorteknik (Chalmers.
    A Slowdown Prediction Method to Improve Memory Aware Scheduling2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Scientific and technological advances in the area of integrated circuits have allowed the performance of microprocessors to grow exponentially since the late 1960's. However, the imbalance between processor and memory bus capacity has increased in recent years. The increasing on-chip-parallelism of multi-core processors has turned the memory subsystem into a key factor for achieving high performance. When two or more processes share the memory subsystem their execution times typically increase, even at relatively low levels of memory traffic. Current research shows that a throughput increase of up to 40% is possible if the job-scheduler can minimizes the slowdown caused by memory contention in industrial multi-core systems such as high performance clusters, datacenters or clouds. In order to optimize the throughput the job-scheduler has to know how much slower the process will execute when co-scheduled on the same server as other processes. Consequently, unless the slowdown is known, or can be fairly well estimated, the scheduling becomes pure guesswork and the performance suffers. The central question addressed in this thesis is how the slowdown caused by memory traffic interference between processes executing on the same server can be predicted and to what extent. This thesis presents and evaluates a new slowdown prediction method which estimates how much longer a program will execute when co-scheduled on the same multi-core server as another program. The method measures how external memory traffic affects a program by generating different levels of synthetic memory traffic while observing the change in execution time. Based on the observations it makes a first order prediction of how much slowdown the program will experience when exposed to external memory traffic. Experimental results show that the method's predictions correlate well with the real measured slowdowns. Furthermore, it is shown that scheduling based on the new slowdown prediction method yields a higher throughput than three other techniques suggested for avoiding co-scheduling slowdowns caused by memory contention. Finally, a novel scheme is suggested to avoid some of the worst co-schedules, thus increasing the system throughput.

  • 209.
    de Blanche, Andreas
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Lundqvist, Thomas
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Disallowing Same-program Co-schedules to Improve Efficiency in Quad-core Servers2017In: Proceedings of the Joined Workshops COSH 2017 and VisorHPC 2017 / [ed] Clauss, Carsten; Lankes, Stefan; Trinitis, Carsten; Weidendorfer, Josef, 2017, p. 1-7Conference paper (Refereed)
    Abstract [en]

    Programs running on different cores in a multicore server are often forced to share resources like off-chip memory,caches, I/O devices, etc. This resource sharing often leads to degraded performance, a slowdown, for the program sthat share the resources. A job scheduler can improve performance by co-scheduling programs that use different resources on the same server. The most common approachto solve this co-scheduling problem has been to make job schedulers resource aware, finding ways to characterize and quantify a program’s resource usage. We have earlier suggested a simple, program and resource agnostic, scheme as a stepping stone to solving this problem: Avoid Terrible Twins, i.e., avoid co-schedules that contain several instances from the same program. This scheme showed promising results when applied to dual-core servers. In this paper, we extend the analysis and evaluation to also cover quad-core servers. We present a probabilistic model and empirical data that show that execution slowdowns get worse as the number of instances of the same program increases. Our scheduling simulations show that if all co-schedules containing multiple instances of the same program are removed, the average slowdown is decreased from 54% to 46% and that the worst case slowdown is decreased from 173% to 108%.

  • 210.
    de Blanche, Andreas
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Lundqvist, Thomas
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Initial Formulation of Why Disallowing Same Program Co-schedules Improves Performance2017In: Co-Scheduling of HPC Applications / [ed] Carsten Trinitis, Josef Weidendorfer, Netherlands: IOS Press, 2017, 1, p. 95-113Chapter in book (Refereed)
    Abstract [en]

    Co-scheduling processes on different cores in the same server might leadto excessive slowdowns if they use the same shared resource, like a memory bus. Ifpossible, processes with a high shared resource use should be allocated to differentserver nodes to avoid contention, thus avoiding slowdown. This article proposesthe more general principle that twins, i.e. several instances of the same program,should be allocated to different server nodes. The rational for this is that instancesof the same program use the same resources and they are more likely to be eitherlow or high resource users. High resource users should obviously not be combined,but a bit non-intuitively, it is also shown that low resource users should also notbe combined in order to not miss out on better scheduling opportunities. This isverified using both a probabilistic argument as well as experimentally using tenprograms from the NAS parallel benchmark suite running on two different systems.By using the simple rule of forbidding these terrible twins, the average slowdownis shown to decrease from 6.6% down to 5.9% for System A and from 9.5% to8.3% for System B. Furthermore, the worst case slowdown is lowered from 12.7%to 9.0% and 19.5% to 13% for systems A and B, respectively. Thus, indicating aconsiderable improvement despite the rule being program agnostic and having noinformation about any program’s resource usage or slowdown behavior.

  • 211.
    de Blanche, Andreas
    et al.
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Lundqvist, Thomas
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Node Sharing for Increased Throughput and Shorter Runtimes: an Industrial Co-Scheduling Case Study2018In: Proceedings of the 3rd Workshop on Co-Scheduling of HPC Applications (COSH 2018): Held together with HiPEAC 2018 / [ed] Trinitis, Carsten; Weidendorfer, Josef, 2018, p. 15-20Conference paper (Refereed)
    Abstract [en]

    The allocation of jobs to nodes and cores in industrial clusters is often based on queue-system standard settings, guesses or perceived fairness between different users and projects. Unfortunately, hard empirical data is often lacking and jobs are scheduled and co-scheduled for no apparent reason. In this case-study, we evaluate the performance impact of co-scheduling jobs using three types of applications and an existing 450+ node cluster at a company doing large-scale parallel industrial simulations. We measure the speedup when co-scheduling two applications together, sharing two nodes, compared to running the applications on separate nodes. Our results and analyses show that by enabling co-scheduling we improve performance in the order of 20% both in throughput and in execution times, and improve the execution times even more if the cluster is running with low utilization. We also find that a simple reconfiguration of the number of threads used in one of the applications can lead to a performance increase of 35-48% showing that there is a potentially large performance increase to gain by changing current practice in industry.

    Download full text (pdf)
    COSH2018-deBlanche-Lundqvist
  • 212.
    de Blanche, Andreas
    et al.
    University West, School of Business, Economics and IT, Division of Computer Science and Informatics.
    Mankefors-Christiernin, Stefan
    University West, Department of Technology, Mathematics and Computer Science, Division for Computer Science.
    Availability of Unused Computational Resources in an Ordinary Office Environment2010In: Journal of Circuits, Systems and Computers, ISSN 0218-1266, Vol. 19, no 3, p. 557-572Article in journal (Refereed)
    Abstract [en]

    The study presented in this paper highlights an important issue that was subject for discussionsand research about a decade ago and now have gained new interest with the current advances ofgrid computing and desktop grids. New techniques are being invented on how to utilize desktopcomputers for computational tasks but no other study, to our knowledge, has explored theavailability of the said resources. The general assumption has been that there are resources andthat they are available. The study is based on a survey on the availability of resources in anordinary o±ce environment. The aim of the study was to determine if there are truly usableunder-utilized networked desktop computers available for non-desktop tasks during the off-hours. We found that in more than 96% of the cases the computers in the current investigationwas available for the formation of part-time (night and weekend) computer clusters. Finally wecompare the performance of a full time and a metamorphosic cluster, based on one hypotheticallinear scalable application and a real world welding simulation.

  • 213.
    Delcorte, Kilian
    University West, Department of Engineering Science.
    Indoor localization for moving elements on stage within the context of entertainment industry2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis explored the most appropriate technology for indoor positioning of automated stage elements within the entertainment industry context. A range of technologies were evaluated, such as camera systems, Bluetooth, GPS, and more. The study primarily focused on the Ultra-Wideband (UWB) Real Time Location System (RTLS) due to its evident potential.

    A comprehensive analysis was conducted to understand the basic mechanics of UWB technology, its comparative advantages, and possible limitations. Practical application of UWB RTLS for static positioning was assessed through experiments within a small-scale setup. These experiments examined crucial factors such as system calibration, noise reduction, signal processing, and accuracy measurement. These tests helped identify challenges and potential solutions for effective implementation of UWB RTLS in such settings

    Subsequently, to further test the technology in a real-world context, field tests were executed in a full-scale stage setup. These tests aimed to mimic the conditions of a live performance environment and provided insights into the challenges and potential solutions for successful implementation of UWB RTLS in larger environment and more complex setting. 

    Results from the experiments conducted in this thesis revealed an accuracy of approximately 30cm in position and 3 degrees in rotation using a complete real-sized Ultra-Wideband system. The precision achieved in these measurements was notably high. 

    These results indicate that the UWB has the potential to greatly enhance the operation of the wagon system, allowing for reliable position retrieval when needed. The accuracy achieved, although slightly below theoretical expectations, is still considered very good and provides a solid foundation for further improvements in the system.

    The thesis concludes with a discussion on the potential future developments of UWB technology within the entertainment industry. Furthermore, it touches upon other fields that could potentially benefit from the application of precise indoor positioning. The work done in this thesis lays a solid foundation for future research and development in the applicationof UWB technology in entertainment and beyond.

  • 214.
    Deng, Donglu
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Selektivplan upprättad i samband med utbyte av generatorer på Arctic Paper2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Den här rapporten innehåller en selektivplan som upprättats i samband med utbyte av tre generatorer på Arctic Paper i Munkedal, samt flera selektivplansuppdateringar i övriga skydd. Arbetet har som syfte att bygga upp fördjupande kunskap i säkringsfri teknik i industriella elanläggningar, vilket genomförs som ett examenarbete för högskoleutbildning som elkraftsingenjör.

    På pappersbruket finns idag tre gamla vattenkraftsgeneratorer. Två av de tre nuvarande generatorerna är små och mycket gamla, generatorer som ska bytas ut mot två nya 3MVA synkrongeneratorer. En av de gamla generatorerna ska användas även i framtiden som reserv. Målet med ombyggnadsprojektet är att öka effekten med upp till tre gånger samt att fördubbla energi produktionen. Ställverk till generatorerna har specificerats tidigare i ombyggnadsprojektet.

    Selektivplanen inkluderar inställningar av reläskydd och effektbrytare för generatorerna. Dessutom kommer befintliga överströmsskydd i anläggningen beaktas. Rapporten baseras på selektivitetsteori och beräkningar av kortslutningsströmmar. Rapporten innefattar även uppdatering av vissa selektivplaner i den befintliga elanläggningen i pappersbruket, detta genom att diskutera problemet och justera inställningar av de befintliga reläskydden

    Tekniska beräkningar och reläinställningsplaner ska fungera som verifikation och dokumentation.

    Download full text (pdf)
    fulltext
  • 215.
    Denys, Kristof
    University West, Department of Engineering Science, Division of Automation and Computer Engineering.
    Circular motion for robotized metal deposition: verification and implementation2013Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Metal deposition is an additive layered manufacturing process that deposits molten metal droplets on a substrate and by repeating this process layer by layer, a complex shaped 3D geometry can be manufactured.

    In this thesis, the metal deposition process is performed by a robot with a wire feeder tool and a laser as energy source to melt the metal wire. The robot programming for robotized metal deposition process can be completely automated by computer aided robotics software. University West is currently developing an add-in application in a computer aided robotics software, Process Simulate, that is capable of programming the robotized metal deposition process.

    The first goal of this thesis was to verify the up to now developed software and the process from CAD drawing down to robot code. Another goal was to find and implement an algorithm that will reduce the number of locations on a circular arc to three locations.

    The algorithm to minimize the locations must be capable of changing all the different curvature paths to linear and circular arc motions which are easy to translate to robot code. The user should be able to decide the fitting precision of the approximated motion path to the original path.

    A real robot cell setup is modelled in Process Simulate. This lets Process Simulate generate the correct robot code for that specific cell.  Since each robot cell has its own unique setup, a custom script will be developed that changes the universal robot code, that Process Simulate generates, to the custom robot code required in this specific robot cell.

    The software is improved and tested from CAD drawing down to robot code but still needs to be debugged more and needs implementation of some non-existing features.

    Download full text (pdf)
    Circular motion for robotized metal deposition
  • 216.
    Depaquit, Valentin
    University West, Department of Engineering Science.
    Simulation Study of Production Line to Increase its Efficiency through an iterative proces: A Case Study with Sanser2023Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The initial reason for this thesis is the desire of Sansera to reach their target production with this production line. They already invest on conveyors to carry part with more reliability between workstations which has led to an under than expected production increase. To achieve the target production this thesis does a simulation study by developing a virtual model of the production line which is a powerful tool to identify weak point and potential areas for improvement.Through an iterative process of model improvement and analysis, various weaknesses in the production line are identified and addressed, leading to the proposal of different solutions. The study focuses on two key approaches for improving production efficiency, which can be valuable for decision-making purposes. However, the conclusions drawn from these improvements are subject to scrutiny due to the quality and accuracy of the underlying data. The validity of the results depends on the data collected and the assumptions made during the modeling process.In conclusion, this study demonstrates the effectiveness of simulation modeling in optimizing production processes and identifying potential areas for improvement. It highlights the importance of data quality and methodology in drawing reliable conclusions.

  • 217.
    Devapal, Arihant
    University West, Department of Engineering Science, Division of Production Systems.
    Automation Solution for Manual Assembly Station2020Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The thesis is about finding a solution for the manual assembly process of making the industrial pumps which is currently present in the company named Parker in Boras. A number solutions is formed and simulated with the help of the software known as ABB Robot Studio. From all the solutions one final solution is thought through the project.

    The result is automation solution which is simulated with using two robots and other components to reduce the cycle time, improve the quality of the product, ensures safety for the workers thus resulting in overall higher production rate.

  • 218.
    Didricksson, Tobias
    et al.
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Norlander, Christian
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    IPv4 eller IPv6 för gemene man i Sverige2021Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    This work compares the time it takes to download a website over IPv4 and IPv6 to then be able to conclude about which protocol a regular user should use to get the best user experience. The starting point is the two older works that have been done on this subject, specifically the newest of these because their method was most similar to ours. The idea was to see if the result would be different if we increased the amount of data collected for analysis. Data has been collected over a whole week, which has given a quantity of 16,749 separate measurements made on 100 different web pages. This data has been analyzed and the specific parts that make up a download of a website have been examined in detail and compared between the IP protocols to see where it differs. The result confirmed our idea that there would be a difference between this and last year's work. However, it was IPv4 that performed significantly worse rather than IPv6 performing better. The result of this work is that IPv6 is faster. 

  • 219.
    Diels, Cyriel
    et al.
    ntelligent Mobility Design Centre, Royal College of Art, London, (GBR); Laboratory for Artificial Intelligence in Design, Hong Kong, (HKG).
    Stylidis, Kostas
    University West, School of Business, Economics and IT, Division of Media and Design. Department of Industrial and Materials Science, Chalmers University of Technology, 412 96, Gothenburg (SWE).
    Mausbach, Artur
    Intelligent Mobility Design Centre, Royal College of Art, London (GBR).
    Harrow, Dale
    Intelligent Mobility Design Centre, Royal College of Art, London, (GBR); Laboratory for Artificial Intelligence in Design, Hong Kong, (HKG).
    Shaping Autonomous Vehicles: Towards a Taxonomy of Design Features Instilling a Sense of Safety2022In: Communications in Computer and Information Science, ISSN 1865-0929, E-ISSN 1865-0937, Vol. 1583 CCIS, p. 172-180Article in journal (Refereed)
    Abstract [en]

    Autonomous vehicles (AVs) are Artificial Intelligence (AI)-enabled service robots. Whilst having the potential to enhance our transport systems and journey experiences, there are concerns that the public may be reluctant to adopt AVs, largely driven by doubts about their safety. In this study, we focussed on the role of the exterior vehicle design to instil a sense of safety on behalf of the passenger and bystander, i.e. pedestrians and cyclists. Senior automotive and transport designers were interviewed to identify key design features which revealed a common understanding of key features but also an apparent dichotomy or incompatibility in terms of design directions when considering passengers versus bystanders. Furthermore, designers’ understanding was largely based on their experience of conventional vehicles leading to uncertainty as to the validity in the context of future AVs. The results provide an initial set of design features that will be tested and evaluated with prospective AV users to explore the potential knowledge gap between designers’ intentions and customers’ expectation. This will provide design practitioners tangible, relatable anchors to direct activities towards critical design features whilst enabling design management to introduce more objectivity in their decision making.  

  • 220.
    Dirki, Lawand
    et al.
    University West, Department of Engineering Science, Division of Automation Systems.
    Kecevic, Amer
    University West, Department of Engineering Science, Division of Automation Systems.
    Utvärdering av nya material för jordningar2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report aims to provide a basis for Vattenfall Eldistribution AB, for any eventual decision making regarding alternative grounding materials that can replace the copper wire. Copper wire is today used for grounding because of its quality, but the high scrap value of copper has made the material theft-prone and characterized companies with costly repairs.

    Some parts of Västra Götaland, where copper wire is used, are seriously affected by thefts. To try to reduce the damage of the thefts, Vattenfall has begun to test replacing the copper wire with Copperweld® (CCS) on their utility poles.

    Copperweld® (CCS) is a copper clad steel wire of much lower scrap value. The material has similar properties as copper wire and can be used as a ground conductor because it fulfills the conductivity requirements of a material, set by Svensk Standard.

    Copperweld® (CCS) should be able to resist corrosion for at least 40 years compared to the copper wire, which in many cases has an unnecessarily long life span. There is no big difference between the purchase price of the Copperweld® (CCS) and the copper wire, and the installation principle is also identical. Based on this evolution, if Vattenfall decide to change copper wire to Copperweld® (CCS), they will save between 10-39 million SEK annually in repair

    expenditures.

  • 221.
    Dittmer, Christian
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Ruponen, Felix
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Modellering av existerande elanläggning i programmet Febdok på Borealis AB i Stenungsund2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Borealis in Stenungsund is Sweden's only polyethylene manufacturer and their cracker plant is one of the most flexible in Europe. As the plant is in constant development, new tools are needed to model the electrical systems that can provide an overall picture. The purpose of the report is to investigate how well it works to implement Borealis existing low voltage substation in the Febdok program, which is used to dimension cables and protection devices in electrical installations according to Swedish standards. To investigate this, models are produced for two different low-voltage substations at Borealis facility in order to evaluate the program. The report produces three general modelling examples in Febdok and performs manual calculations to validate the results in the program. The examples describe different operating modes for a simple low-voltage network in normal operation, operation with UPS and operation with a backup generator. Results of the manual calculations performed are close to the corresponding values given by Febdok. Calculation methods and resulting accuracy are discussed in each example based on sources of error and the simplifications made. Based on the general modelling examples, the modeling of the selected low-voltage substations is performed in Febdok. Details have been omitted for reasons of confidentiality and parts that are difficult to model have been described in detail. Problems with the modeling are discussed based on the specific switchgear but also from a general perspective. The report shows that it is possible to create a model of an existing low-voltage substation in Febdok if certain methods are used to circumvent safety functions and control functions in the program. In addition, it is described how values of currents and voltages in Febdok can be reproduced using manual calculations. The examples used describe which parameters have been used to calculate load currents, voltage drop, fault currents and a discussion of deviations is also made when the results are compared. Finally, several proposals for improvements are described that simplify modeling of existing facilities.

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  • 222.
    Dizdarevic, Semir
    University West, Department of Engineering Science.
    Substation power quality measuring units in Oman: solutions to connection problems2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Unipower AB had a big project in the Sultanate of Oman installing 200 power quality measuring devices in 50 substations in the outskirts of the city Sohar, and also smaller projects in the city Muscat. Finishing the project and summing up the lessons learned will be the main goal of this project.

    Connection Problems were encountered with the measurement equipment in the Sohar region, about 20% had connection, the rest had no connection at all. The goal was to find a solution to the connection problem. At the end the solution was to establish the sim cardsof the routers in every station, even the stations that work. That required a presence in Oman and to access to the stations.

    Other goals were to have meetings and discussions about different solutions, ideas or upgrades for the other customers for Unipower in Oman.

    The work include an analysis of the procedure of the installation work in Sohar as well in Muscat and also a white paper on the experiences gathered. A project list was created based on these experiences.

    The conclusion is that about 85% of the stations in Sohar now works, the other 15% does not work due to no reception inside the stations. Tests were made Showing the signals available hence the solution is to use an antenna outside each station to get a signal for the router.

  • 223.
    Djebbar, Fatiha
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Securing IoT data using steganography: A practical implementation approach2021In: Electronics, E-ISSN 2079-9292, Vol. 10, no 21, article id 2707Article in journal (Refereed)
    Abstract [en]

    Adding network connectivity to any “thing” can certainly provide great value, but it also brings along potential cybersecurity risks. To fully benefit from the Internet of Things “IoT” system’s capabilities, the validity and accuracy of transmitted data should be ensured. Due to the constrained environment of IoT devices, practical security implementation presents a great challenge. In this paper, we present a noise-resilient, low-overhead, lightweight steganography solution adequate for use in the IoT environment. The accuracy of hidden data is tested against corruption using multiple modulations and coding schemes (MCSs). Additive white Gaussian noise (AWGN) is added to the modulated data to simulate the noisy channel as well as several wireless technologies such as cellular, WiFi, and vehicular communications that are used between communicating IoT devices. The presented scheme is capable of hiding a high payload in audio signals (e.g., speech and music) with a low bit error rate (BER), high undetectability, low complexity, and low perceptibility. The proposed algorithm is evaluated using well-established performance evaluation techniques and has been demonstrated to be a practical candidate for the mass deployment of IoT devices.

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    Electronics
  • 224.
    Djebbar, Fatiha
    et al.
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Nordström, Kim
    Cybersecurity Product Compliance Group,Stockholm (SWE).
    A Comparative Analysis of Industrial Cybersecurity Standards2023In: IEEE Access, E-ISSN 2169-3536, Vol. 11, p. 85315-85332Article in journal (Refereed)
    Abstract [en]

    Cybersecurity standards provide a structured approach to manage and assess cybersecurity risks. They are the primary source for security requirements and controls used by organizations to reduce the likelihood and the impact of cybersecurity attacks. However, the large number of available cybersecurity standards and frameworks make the selection of the right security standards for a specific system challenging. The absence of a comprehensive comparison overlap across these standards further increases the difficulty of the selection process. In situations where new business needs dictate to comply or implement additional security standard, there may be a risk of duplicating existing security requirements and controls between the standards resulting in unnecessary added cost and workload. To optimize the performance and cost benefits of compliance efforts to standards, it is important to analyze cybersecurity standards and identify the overlapping security controls and requirements. In this work, we conduct a comparative study to identify possible overlaps and discrepancies between three security standards: ETSI EN 303 645 v2.1.1 for consumer devices connected to the internet, ISA/IEC 62443-3-3:2019 for industrial automation and control systems, and ISO/IEC 27001:2022 for information security management systems. The standards were carefully chosen for their broad adoption and acceptance by the international community. We intentionally selected standards with different areas of focus to illustrate the significant overlaps that can exist despite being designed for different environments. Our objective is to help organizations select the most suitable security controls for their specific needs and to simplify and clarify the compliance process. Our findings show a significant overlap among the three selected standards. This information can help organizations gain a comprehensive understanding of common security requirements and controls, enabling them to streamline their compliance efforts by eliminating duplicated work especially when meeting the requirements of multiple standards.

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  • 225.
    Dure, Kristin
    et al.
    University West, Department of Engineering Science, Division of Computer and Electrical Engineering.
    Wallman, Gustav
    University West, Department of Engineering Science, Division of Computer and Electrical Engineering.
    Plan för riktningsprov av nya reläskydd för Uddevalla Energi Elnät AB2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    After the storm Gudrun the accessibility requirements increased for the powerlines. In order to weatherproof the powerlines, the electric companies replaced a large proportion of existing overhead lines with underground cable. Over the last 10 years, Uddevalla Energi have buried about 150 kilometers of overhead lines.

    Transient and intermittent earth-faults occur mainly in cable networks and due to increased cabling the presence of transients intensifies in power companies' networks. These transients are problematic to detect with older protective relays and therefore has Uddevalla Energy Electricity Networks AB decided to purchase new ones.

    This thesis was commissioned by Uddevalla Energi Elnät AB to examine how the directional earth-fault and transient/intermittent earth-fault protection functions works on ABB's REF615. A manual has been prepared for how to find indications on the REF615s' interface when ground faults or intermittent faults occurred.

    When new protective relays are taken into service, it’s advisable to test these to determine that they´re determining the direction of faults correctly. This is done by creating real ground faults in the grid. This thesis describes how these tests are carried out and where in the network it is appropriate to conduct these tests

  • 226.
    Därnemyr, Johan
    University West, Department of Engineering Science.
    Åtgärder för att minimera kommunikationsstörningar vid avläsning av elmätare via elnätet2009Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report handles the issue of communication problems that appears between the components in the ADDAX system, mainly between the router and meter. The system is built around a hierarchy with the ADDAX server at the top and the meter at the bottom. The system uses the power grid as communication medium, this is called PLC “power line communication. The task has bin to se how the system works, witch geographical areas that have problems with communication, localization of source for the disturbing of the communication, attend to the disturbing and to make a flow chart that the electricians can use when they are conducting a measurement. A program called “TC Meter Surv SA Edition 0.61” was used for finding which areas that have problems with the communication. Two areas were chosen, one in the countryside and one in central Grästorp. The program firs showed that some meters where missing but when the measurements where don the program showed that all meters where missing. The reason for this problem is unknown. The problem in the central Grästorp area is not in the LV butt in the MV. The conclusion will be that al of the software must be updated and that the master routers could be replaced with a never versions before any new measurements are to be done. The power quality measurement instruments that has bin used are PL-monitor and HF+. On other conclusion that can bi don is that HF+ is superfluous because it chows the same information that PL-monitor dose but it’s harder to interpret. In the area on the countryside the solution to the communication problem can bi to install a filter. Other solutions to PLC problems can bi to switch the phase the meter uses for communication, move the meter farther from the customer, installing a repeater or in consultation with the customer get him or here to turn of the devise that disturb the communication under some ours in a 24-hour period.

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    FULLTEXT01
  • 227.
    Edström, Johan
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Redovisning av lantmäterimyndigheternas handläggningstider och hur de påverkar byggbranschen2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    That the need for housing is very large and will continue to be so for many years in Sweden is well known. To handle the emergency situation, the construction process needs to speed up.  On January 19, 2017, an article was published on the Swedish government's website describing that the survey processing times have to be reviewed. The long processing times are slowing down the construction process and thus adversely affect the construction process in a negative way. The National Land Survey is an authority that works to measure, regulate and distribute cadastral boundaries. This means that The National land survey has a major role in the plan process and because of that a significant impact on the time of the plan process. Especially during the work on detail plans. This bachelor thesis has been carried out at the University West, Sweden, with the purpose of investigating how Sweden’s survey agencies administrative processes affect the construction process.

     Of Swedens 39 municipal survey agencies, 29 have contributed with processing statistics. The study's results have shown that the processing times of municipal surveyors on average are 47.5 weeks in 2016. At the Land Survey, the corresponding equivalent value is 55.1 weeks in 2016. This study clearly indicates that processing times are too long given to what the construction industry is looking for. A majority in the construction industry are saying that a processing time that is longer than 26 weeks is unreasonable in most cases. Although this study has shown that, the construction industry is overall satisfied with the work carried out by the survey agency. In 2016, a new section came into law that will give rights to a broadband connection within a maximum of four months after the application. This means that the survey agencies may be required to give priority to these types of cases, and thus administrative processing times may be affected. The result has shown that there are four different possibilities for getting priority in the line, however, it is too early to state with certainty that the processing times will be affected by the new law.   

  • 228.
    Ehnberg, Jimmy S.G.
    University West, Department of Technology, Mathematics and Computer Science, Division for Electrical Engineering and Land Surveying.
    Autonomous power systems based on renewables: On generation reliability and system control2007Doctoral thesis, comprehensive summary (Other academic)
  • 229.
    Ek, Albert
    University West, Department of Engineering Science, Division of Computer and Electrical Engineering.
    En prestandajämförelse av minnesbaserade schemaläggningsmetoder2014Independent thesis Basic level (professional degree), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    When the number of cores per processor increases the demand on the memory buss bandwidth increase as well. The memory buss contains the traffic that flows between the processor and the memory modules. In an attempt to avoid that programs become affect-ed by the limited memory buss bandwidth, co-scheduling is used. A co-scheduler consists of two parts, an algorithm and a characterization method.

    Four characterization methods are tested in this project, Stack distance profile, Memory bandwidth usage, Miss rate and Slowdown based classification and they are co-scheduled with ten programs from the NASA advanced super computing division [6]. The goal is to see how good or bad the characterization methods perform and if the performance differ on the different processors.

    All programs are first executed without co-scheduling, solo and pairwise on the processors. After the executions are finished a baseline is created which contains all the combinations of programs and the slowdown value they received. The baseline can then be used to com-pare the characterization methods with each other, by seeing what slowdown the character-ization methods got relative to the baseline executions. The names of the three machines that contains the different processors are Hp3, T7500 and Kraken and on these, ten pro-grams are co-scheduled with four different characterization methods.

    Slowdown based classification was the characterization method who performed best out of the four characterization methods. It got an average value among 30% of the best execu-tions. Miss rates got an average value among 60% of the best executions and Memory bandwidth usages average value was among 30% of the best executions. Stack distance profile performed the worst and got an average value among 70% of the best executions

  • 230.
    Ekergård, Boel
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Leijon, Mats
    Department of Engineering Sciences, Uppsala University, Uppsala, Sweden.
    Eddy Current Losses in Solid Pole Shoes in a Two-Pole Permanent Magnet Motor2021In: Engineering, ISSN 1947-3931, E-ISSN 1947-394X, Vol. 13, no 10, p. 536-543Article in journal (Other academic)
    Abstract [en]

    The aim of this paper is to present the eddy current losses in solid pole shoes in a permanent magnet two-pole electric motor. In the presented paper, the authors have chosen to work with three different analytical models, Carter’s theory, Gibb’s theory and Lawrenson’s theory, each with different degree of accuracy and simplifications. The results from the analytical models all present relatively low eddy current losses, giving the designer valuable arguments to utilize solid pole shoes, as a rotor with solid poles is from a construction point of view a more suitable choice, increasing the mechanical stability and reducing the production cost, compared to the laminated design.

  • 231.
    Ekergård, Boel
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Leijon, Mats
    Uppsala University, Swedish Centre for Renewable Electric Energy Conversion, Department on Engineering Sciences, Uppsala, 751 21, Sweden; Chalmers University of Technology, Department of Electrical Engineering, Gothenburg, 412 96, Sweden .
    Longitudinal end effects in a linear wave power generator2020In: Energies, E-ISSN 1996-1073, Vol. 13, no 2, article id 327Article in journal (Refereed)
    Abstract [en]

    Even though the magnetic circuit of a linear electric machine is very similar to a rotating electric machine, they diverge in one fundamental property. The linear generator is open in both ends, i.e., the magnetic circuit is non-symmetric. This paper investigates and discusses the drawbacks of this non-symmetric design in a linear permanent magnet generator, installed in a wave energy conversion system. A two-dimensional geometry has been utilized for the numerical calculations in a finite element method simulation tool. The results present an increased cogging force and significant core losses in the translator as consequences of the longitudinal ends in the machine. © 2020 by the authors.

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  • 232.
    Eklund, Sara
    et al.
    University West, Department of Engineering Science.
    Kaalstad Pettersson, Patrik
    University West, Department of Engineering Science.
    A Hololens 2 experiment on subtle guidance2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    New technology is created every day and the buzz around you keeps getting noisier. Because of this, people are turning their minds towards calm technology. Here you try to make equipment and programs interact with the user in a quieter way. A way of doing so in AR is the use of subtle hints instead of flickering highlighters as a guidance. This paper describes an experiment using subtle guidance in HoloLens 2, an augmented reality head worn device. We want to research to what level subtle guidance can affect the given task and what parameters makes the subtle hint comfortable touse. It is also of interest to use the eyetracking in the HoloLens to determine when the subtle hints make an effect on the user. In the study we used a puzzle-program especially designed for this task containing puzzles with and without subtle guidance. The participants who were recruited for the experiment, were in addition to the puzzle-test interviewed, and their answers among with there corded data was analyzed and discussed at the end of the study.

  • 233.
    Eklund, Sebastian
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Strömberg, Daniel
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Beredning av lokalnät i Bäckefors2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This degree project describes the procedure how preparation work is executed both for high voltage and low voltage power grid. The preparatory work concerns a power grid in Bäckefors. Today’s high- and low voltage power grid consist of overhead power lines and will be demolished. The overhead power lines will be replaced by underground cables. An underground cable power grid secures a higher reliability which means less interference and fewer disruptions in the power grid. During the project, map studies have been performed to give an overview over the area. After the map studies have been performed, a field visit has been conducted to give a better view of the area and see the eventual problems that can occur during the cable laying. Major obstacles and problems have been avoided. One guided drilling will be performed to pass a railway track in combination with a road. The project will include the demolition of 5 427 meters of high voltage power line and 3 799 meters of low voltage power line. 5 pole-mounted stations including transformers will be replaced by new substations and transformers, all of them 100 kVA each. 5300 meters of high voltage cable and 3500 meters of low voltage cable will be placed. 10 new cable distribution cabinets will be placed in the area. In total the project will affect 20 subscribers. A P2 cost calculation has been carried out and the total cost for the reconstruction in the power grid will be 3,37 million SEK.

  • 234.
    Ekstrand, Charlotta
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Löfgren, Emelie
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Förslag till sammankoppling av distributionsnät över koncessionsgränsen mellan Trollhättan Energi Elnät AB och Uddevalla Energi Elnät AB2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This bachelor’s thesis has been carried out on behalf of Trollhättan Energi Elnät AB and Uddevalla Energi Elnät AB. This is a preliminary study of a possible interconnection between the two companies 12 kV electric power networks at the joint concession border in the rural area Öresjö. It’s the technical and economic aspects of an interconnection that has been studied.

    The tolerance for interruptions in the electricity supply is decreasing in society which requires high service reliability from the electricity network operators. Due to legal requirements the electricity network operators are obliged to compensate customers which are affected by unplanned interruptions longer than twelve hours. A possible interconnection would provide the operators with an additional stand-by supply in the area and thereby increase the service reliability.

    The interconnection of the two electricity grids is possible between the substations Hedetorpet and T185 Fiskaretorpet who are situated one kilometer from each other. Calculations have been carried out on the basis of two possible approaches with two different load currents, which shows that the two power grids have sufficient capacity to cope with an interconnection. The two electricity network operators will have to compensate for the increased ground fault currents in the electricity grid.

    The planned rout for the new line will follow the road 2027 and will consist of a 150 mm2 aluminum PEX-cable and a new substation containing a 100 kVA:s transformer. In order to avoid the application for line concession a high voltage cable cabinet could be placed on the concession line.

    The budget for an interconnection between the two electricity grids, which has been compiled from EBR's design directory P2, is estimated to 1.5 million SEK including an additional fee of 10 % for unforeseen costs.

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  • 235.
    Ekström, Philip
    University West, Department of Engineering Science.
    Implementation av Python via NETCONFoch RESTCONF: En jämförelsestudie2023Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [sv]

    Det går att hantera nätverksenheter och nätverk på olika sätt. Två av dessa sätt är RESTCONF och NETCONF. Denna undersöknings syfte är att ta reda på vilken av dessa två protokoll som är snabbast och om storlek på nätverket har påverkan på vilket att dessa protokoll som bör användas. Resultatet visar att RESTCONF är snabbare än NETCONF på ett nät med tre routrar och två switchrar. RESTCONF är även snabbare än NETCONF på ett nätverk som består av 17 routrar och fem switchrar. Både NETCONF och RESTCONF tar längre tid i nätverket med fler nätverksenheter än i nätverket med färre nätverksenheter.

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  • 236.
    Elgh, Patrik
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Lundmark, Tobias
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Elprojektering av nya lokaler2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis has been carried out on behalf of Midroc Electro AB in Stenungsund. The assignment was to design the electrical installation for an extension of new premises and come up with a cost estimate for this. The extension will include electrical installation in six new offices, a conference room, storage room and an equipment room.

    The project planning is carried out in accordance to Swedish national electrical safety board's regulations and Swedish standards thus meeting the requirement for good electrical safety practice.

    The lighting in the premises is designed according to the guidelines of the Swedish work environment authority, since poor lighting can cause stress, fatigue and glare. Control of lighting will be made using a combination of two intelligent control systems, KNX and DALI.

    In the storage room, corridors and technology room the lights will be controlled by motion sensors. In the conference room the lights can be controlled with push buttons or by remote control. In offices the lights will be controlled by a push button. In offices and the conference room network sockets will be installed. In the corridors there will be power- and network sockets above the ceiling for wireless access points. General sockets for power have been allocated according to Swedish standards.

    The Installation drawings are rendered in the computer program EasyEL and resulted in lighting-, ducting-, power- and telecommunication drawings. Sizing calculations and documentations of the electrical installations were carried out in the computer program FEBDOK.

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  • 237.
    Eliasson, Peter
    University West, Department of Engineering Science, Division of Automation Systems.
    Elenergibesparande åtgärder för ett flerbostadshus i Säffle2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this work was to find energysaving arrangements for an apartment block situated in Säffle. The energysaving comprises lightning and appliances. The apartment block has an electricity consumption of 9 189 kWh/year which covers applianceroom, lightning indoors and lightning outdoors. Because of confidentiality the calculations are based on a fully occupied apartment block, therefor total annual saving will exceed current electricity consumption. Improvement measures for applianceroom is to change the drycleaner,

    Miele t5213, to drycleaner Electrolux T4300 LE. The drying cabinets Elektro Helios TK 7022 and ASKO nimo ETS 1900 are changed to two Cylinda TS 190VP ECO drying cabinets. These measures give an energysaving of 9 255 kWh/year calculated on a fully preoccupied apartment block and that all resident use the laundry.

    For indoor lightning the 58 W T8 strip lights are changed to 35 W T5 and 22 W T8 strip lights are changed to 13 W T5. The measure give an annual energysaving of 2 137 kWh. For outdoor lightning the 125 W mercury lights are changed to 60 W LED-lamps and the 125 W halogen lamps are changed to 40 W LED-lamps. The measure give an annual energysaving of 2 060 kWh. Total saving becomes 14 492 kWh/year which corresponds to 52 % lower energy consumption. Total investment is estimated to 75 000 sek (material 50 000 sek and work 25 000 sek) and the repayment period is calculated to 7,5 years. The result is a hint of what energysavings that can be achieved. Manual steering of the lightning should be changed into presencesensor and can be complemented with a foglightsystem. These measures are not included in the calculation of the total annual energysaving.

  • 238.
    Ellström, Alexander
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Sten, Anton
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Guide för projektering inom lågspänning2020Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report is written in conjunction with a low voltage project planning guide developed by the authors. The purpose of the work is to develop an educational guide for newly employed connection technicians and engineers, that is also available as a tool for experienced planners at the Network Connections department at Vattenfall Eldistribution AB. Another purpose is to give the reader an understanding and insight into the process that is the basis for establishing a project planning of a new connection in the electricity grid. Literary studies and private conversations with several planners at the company were used to collect relevant information. The authors have also participated in an in-depth training of how a new connection in low voltage networks is executed.

    The report describes the two areas of planning and project planning for which the work roles of technicians and engineers at Vattenfall Eldistribution AB are responsible. The planning stage includes, among other things, the dimensioning of the new connection in relation to its surrounding environment, while the project planning phase is focused on using calculations of the electricity quality parameters in the NETBAS computer system.

    The guide is developed using PowerPoint and the features offered by the program, thus enabling a user-friendly and easy-to-navigate guide and design. The homepage of the guide shows a flowchart of the six steps that are needed when planning and project planning a new connection. The user can seamlessly move back and forth between the different steps that contain information and procedures for performing specific tasks.

    A test project planning of a fictitious new connection has been performed by the authors, where the guide has been followed step by step. After reviewing the results of the test, the authors consider that the guide fulfils its purpose as a training material for new employees at Vattenfall Eldistribution AB

  • 239.
    Elofsson, Rickard
    et al.
    University West, Department of Engineering Science, Division of Computer and Electrical Engineering.
    Karlsson, Anders
    University West, Department of Engineering Science, Division of Computer and Electrical Engineering.
    Undersökning av intermittenta och transienta jordfelsfunktioner för reläskydd2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The hurricane Gudrun in 2005 left major damages on the Swedish grid. Therefore new grid regulations concerning downtime were implemented in Sweden. Resulting overhead lines were replaced with underground cables. The first well known effect of underground cables during a fault is the generation of capacitive earth fault current in the grid. The second well known effects are intermittent and transient earth faults in the underground cables. These faults usually occur in cable joints or other insulation defects in cables. It has been found that the recent earth fault protections have problems with detecting intermittent and transient earth fault, this in turn causes disconnection of the power transformer which yields a non-selective disconnection at the distribution system. This work has been carried out at Göteborg Energi Nät AB. The purpose of this work is to study and examine how some of the most common earth fault relays on market detects and manages intermittent and transient earth faults. The study shows that the fault detection became more complex by increased generation of capacitive earth fault currents. The main reason is that the resistive part of the fault current is too small in comparison to the capacitive part. Therefore the Petersen coil compensation calibration is vital in order to minimize the generation of capacitive earth fault currents. The study finds only minor theoretical differences between the intermittent and transient fault detection. One deviation found was in the protection MiCOM P132 which is designed and constructed with an analogue detection circuit in order to enhance the protection functionality. The remaining earth fault relays are designed and constructed with digital technology. The major difference between the digital technique relays is that the sampling rate is different in different models. A well calibrated compensation simplifies fault detection which results in simpler earth fault protection relays meet the detection requirements of the represented company. To achieve accurate results, live tests are highly recommended

  • 240.
    Emami, Iman
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Pilqvist, Martin
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Implementering av översiktsbild för att hjälpa driftoperatörer bistå anvisningar från Starta Sverige2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Vattenfall is currently working to meet the instructions of the project "Starta Sverige" that is created by the Swedish transmission system operators in which a cooperation between different control rooms and control centers will minimize problems during power system restoration after a major disturbance. This work aims to aid the completion of the strategy in Starta Sverige for the control-room operators at Vattenfall to reconnect load after a system failure in the simplest, fastest and safest way possible. This will be done through development of a schematic overview to Vattenfall's operating system.

    The way to achieve this is to conduct interviews with control-room operators and operating system specialists with the purpose of understanding their needs and expectations but also to understand the technical limitations of the operating system. The development has been performed in an iterative way where follow-up interviews weremade to persistently improve the schematic overview.

    The result is a schematic overview roughly the size of an A4-papersheet. Technical limitations prevent some of the control-room operator's wishes to become reality, such asto use graphs to show the remaining active power to reconnect. There is one schematic overview to each of the eight zones of Starta Sverige in Sweden which will contain information about relevant stations, reactive components and transformer taps in addition to showing the voltage and frequency for the connection point to the national transmission grid. According to the instructions of Starta Sverige there is a priority to present the available and used active power since this information is important for system restoration.

    The schematic overview is planned to be implemented in the operating system the same year as the publication of this report, although currently an example is accessible in Vattenfall's operating system. Since the schematic overview is planned to be used after amajor system breakdown there's an uncertainty when the actual use will be.

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  • 241.
    Engström, Anders
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Hallnor, Fillippa
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Registerföring av rennäringens utökade rättigheter: Hantering av sedvanerätter i fastighetsregistret gällande mark med statligt ursprung2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Reindeer keepers in Sweden have the right to pursue reindeer husbandry on land that they do not own. That is governed by law. The rights are more extensive regarding land that is now, or formerly was, owned by the Swedish state. The reindeer keepers may for example cut down trees in order to collect wood and fuel needed for their business. Lantmäteriet (the Swedish mapping, cadastral and land registration authority) shall since 30 June 1992 insert a comment in the real property register to inform about the existence of the extensive right of reindeer keeping, actuated when the state sells land to a private owner. The main focus of the study is to investigate how Lantmäteriet has handled the insertion of such information in Arvidsjaur, Gällivare and Vilhelmina municipality between year 1992 and 2017.  By finding and examining transcripts from the real property register on properties which the state has sold land to, the study aims to show how the task has been handled. The sale of land owned by the state has mainly been managed by the company Sveaskog AB. This derives a natural selection consisting of land transfers made from properties owned by that company. The properties that have received land are categorized with respect to whether they have information about the extensive right of the reindeer keepers and to who the owner of the property is. This determines whether the task has been handled correctly or not. The information has been incorrectly left out in 65 % of the insertions in Gällivare and nor in Arvidsjaur or Vilhelmina has the work been done correctly. The result also gives an insight into the working routines of the cadastral surveyors and it shows how they approached the task. They seem to have developed an approach that goes beyond what is written in the guidelines from Lantmäteriet. This is one of the phenomena which is further discussed in the analysis. The study analyzes the underlying factors to why the information is not inserted. A discussion is held about how the formulation of the information could be clarified to make it easier for everybody to understand it. The conclusion tells that the work has been differently managed in the different municipalities. The work routines should be clarified or incorporated into the guidelines from Lantmäteriet and the current legislation should be questioned since we consider that it doesn’t always follow the purpose of the information. Concrete suggestions show how to more comprehensively present the information.

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  • 242.
    Ericsson, Mikael
    et al.
    University West, Department of Technology, Mathematics and Computer Science.
    Nylén, Per
    University West, Department of Technology, Mathematics and Computer Science.
    Danielsson, Fredrik
    University West, Department of Technology, Mathematics and Computer Science.
    Carlsson, Henrik
    University West, Department of Technology, Mathematics and Computer Science.
    Off-line programming of robots for metal deposition2005In: Trends in welding research: Proceedings of the 7th international conference, May 16-20. Pine Mountain, Georgia, 2005, p. 629-634Conference paper (Other academic)
    Abstract [en]

    Metal Deposition (MD) is a rapid prototyping technique to build parts by depositing metal in a required fashion. When a complex-shaped part is to be built, a simulation tool is needed to define robot trajectories. Three different simulation-based methods for robot trajectory generation are introduced and compared in this study. The methods are; reversed milling, adapted rapid prototyping and application programming in a computer aided robotics software. All methods were shown capable of creating robot paths for complex shapes, with the CAR software approach being the most flexible. Using this method, the geometry to be built is automatically sliced into layers and a robot path is automatically generated. The method was tentatively evaluated and appears to provide a powerful technique in the design and optimisation of robot paths for MD. Experiments showed that it is possible to manufacture fully dense parts using an Nd-Yag laser.

     

  • 243.
    Eriksson, Anders
    et al.
    University West, Department of Engineering Science.
    Johansson, Katarina
    University West, Department of Engineering Science.
    Studie över möjliga publika laddstationer för elfordon i centrala Trollhättan2022Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In connection with Västra Götaland setting a regional climate goal to be fossil-free by the year 2030, the city of Trollhättan adopted the same goal. Part of the transition to becomefossil-free is to increase the proportion of electric vehicles. This means that an expanded charging infrastructure is needed, and above all an expansion of the public charging infrastructure. For those who live in the central district of Trollhättan without their own or rented parking space with charging options, this can be considered as an obstacle to switching to an electric vehicle. 

    When planning the new charging stations, not only does the municipality requirements for the city plan have to be met, the existing electricity network in the area must also have sufficient electrical capacity. This means that the electricity grid must be able to handle the increased power consumption. Charging several electric cars with high power consumption at the same time results in a peak in power consumption in the grid. To prevent this, load balancing and so-called “smart charging” can be used. For the grid company, this means that the electricity network does not risk being overloaded and that the existing network station transformer does not need to be replaced. For the electric car owner this can mean a decrease in charging costs as the charging is done when the electricity price is lower.

    The authors of this report have chosen a selection of streets in central Trollhättan as proposed locations for the charging stations. These streets were chosen by taken both the surrounding environment and the regulations is the city plan into account. In the southern part of the city center, the charging stations can be used mostly by residents in the area. In the northern part of the city center, the charging stations can be used by residents as well as visitors to the city center. This benefits the business community as long-distance guests can use the charging stations. By limiting the power output at the charging points the risk of overloading the existing electricity network can be avoided. This means that a lower main fuse can be selected, which results in lower costs. Of the 7 proposed streets, only one of the streets, Charging station 7, will have a limited capacity. If the capacity of Charging station 7 shall increase it will require a replacement of the local substation’s transformer.

    The conclusion of the report is that there is a need to review the charging infrastructure in central Trollhättan. Demand for charging stations will increase as the sales of electric cars continue to reach new heights in the future. 

  • 244.
    Eriksson, Christoffer
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Framtagning av tillförlitlighetsdata för ställverksapparater i Vattenfalls regionnät2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Higher demands are placed on network operators regarding the delivery quality. Part of the decision-making in constructions or renovations is to estimate costs for any possible fault on the network. To make these calculations, it is required that the correct input data is available. The relevant data shows what can be expected of a component, how reliable the devices are. This report focused on what data is available to calculate a result with reliable fault frequency for switchgear devices from different sources. The research only includes the transmission network and focus has been on finding reliable sources where the results has been documented, which presents the opportunity to make an assessment of the reliability. Cigré has previously conducted the most comprehensive report and collected data from around the world. Electrical companies from 28 countries contributed which was analyzed and summarized in multiple reports. Other sources reviewed for this research are ENTSO-E and Nordel, who for several years has compiled statistics from the Nordic countries in annual reports. Something that attracted attention in the work is that Vattenfall has performed an incorrect reporting of transformer fault in recent years. This results in multiple failure rates of Nordel and ENTSO-E is not useful, it should be reviewed by Vattenfall to contribute to this collection statistics that are useful for all grid companies. In this research, recommended error rates are presented based on the collected statistics. The values presented are for power transformers, circuit breakers, disconnectors, earthing switches and instrument transformers. The voltage levels included varies for the different components.

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  • 245.
    Eriksson, Daniel
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Dimensionering av matning för nyskänkugn hos SSAB i Oxelösund2020Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    SSAB in Oxelösund will build an electric arc furnace to transform business from a mainly ore-based production, with blast furnaces, to a scrap based production. Together with the construction of the electric arc furnace, a new 130 kV overhead line and a 30 kV substation will be built. The 30 kV substation will feed one electric arc furnace and two ladle furnaces.

    One of these ladle furnaces is currently (2019) being fed with 10 kV, but is going to be converted to 30 kV, while the other one is a new electrically identical furnace. The connection of these three furnaces to the 30 kV grid is done in order to limit the distribution of harmonic distortions and flicker to the other loads. The furnaces on the 30 kV grid will be connected to a common electrical filter.

    The electric arc furnace and the ladle furnaces will be operational and produce steel in the first quarter of 2024. Since the installation will be performed some years ahead the short circuit impedance is not known. The cable between the main substation (OT40) and the ladle furnace substation (SU2) was being selected according to thermals and short time currents which determined the cable to consist of a single core cable with 300 mm2 aluminium conductor isolated by XLPE-isolation. This is provided that the cable is mountedin a triangle formation along a path with temperatures at maximum 35 C and is placed in such a way that the cable is not influenced thermally by other cables. Short circuit and voltage drop calculations are made in the program GNU Octave. The highest three phase and the lowest two phase short circuit current is calculated in every substation.

    The overcurrent protection is set to a maximum disconnection time of 0.9 seconds. A blocking logic is being used to further ensure a selectivity in the facility. The logic means, according to SSAB praxis, that the protection closest to the fault blocks the upstream short circuit protection ( I). The earth fault protection is designed around using a neutral grounding resistor of 10 A. The earth fault protection is directional and is being released by the neutral displacement protection to asure no unwanted tripping of the earth fault protection by change-over switching or faults in the grid. The release of the protection works with detuning up to about 21 A.

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  • 246.
    Eriksson, Kevin
    et al.
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Lunde, Jesper
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Teknikstudie över olika laddningstekniker för elfordon2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Electric vehicles are on a strong rise with increasing sales and larger infrastructure every year. For a fast-growing industry like electric vehicles, it is interesting to look at how they are charged as this affects all owners of electric vehicles. The commercial technologies for electric vehicle charging today are conductive and have been standardized. However, several different standards exist, partly competing with each other. The report describes the major standards of IEC, CCS, CHAdeMO and GB/T, in addition to these, there is also the car manufacturer Tesla with its own standard. The thesis takes a closer look at some development projects to see in which directions the technology is developing. Among other things, conductive transmission via rail in or on the road and transmission by wires above the road, but also upgrading of existing standards. Inductive charging projects are further investigated with static inductive charging stations and dynamic inductive charging while driving. The thesis investigates dynamic inductive charging in deeper detail. There is a lot of research and projects going on, but there are still many problems to solve in order to commercialize the technology. The advantage of inductive charging is that it can be wireless and when the vehicle is charged while driving, fewer stops are required to charge. The technology, on the other hand, has some efficiency issues that can vary greatly depending on how the vehicle is aligned towards the transfer coil. Communication to pay for charging, among other things, is still early in the development, as a very high communication speed is required when charging during travel. The writers view is that the major development and expansion will occur in inductive transmission as well as upgrading of the existing conductive standards. Standardization of the upcoming technologies is considered important in order to avoid creating many incompatible technologies on the roads. Work on standardization of inductive transmission is in progress but is not yet complete.

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  • 247.
    Eriksson, Kevin
    et al.
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Seidl, Kristoffer
    University West, Department of Engineering Science, Division of Computer, Electrical and Surveying Engineering.
    Reservkraft i Vattenfalls norrlandsnät2016Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    Today, the power grid in the Swedish province of Norrland is particularly sensitive to interruptions. With a high proportion of overhead and radial lines and increasing demand on reliability of the power supply means backup power supply is often necessary to meet the requirements.

    By studying interruption reports available at Vattenfall the necessary data about faults that exceed statutory periods was gathered. Observations in Vattenfalls network information system formed the basis for the assessment of the grid structure in the area.

    Information about the data on the relevant plant sections was retrieved via the manufacturers' datasheets.

    Today access to the back-up power is unevenly distributed where sensitive areas in general have considerably less access to back-up power than less sensitive areas. In addition, the available back-up power is not used to the extent it would be possible because it can be seen as a waste of resources. Relocation of some back-up power to areas with high fault rates is suggested in order to reduce the compensation that must be paid to the customers in case of long power outages.

    It was also examined during the project if proper fault disconnection within a reasonable time frame is met. This resulted in a table that can be used to verify if the connected power supply has the required short-circuit power to ensure fault disconnection.

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  • 248.
    Eriksson, Kim
    University West, Department of Engineering Science.
    Jämförelse mellan två automationsverktyg: Ansible och Puppet Bolt2022Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    In today's network, automation tools are becoming more and more important. This thesis report is about a comparison of two automation tools Ansible and Puppet bolt. Among other things, it has determined which tool is best for the people who use them and which tool has the best performance.

    Ansible is an agentless tool that uses YAML for it’s scripts. The scripts are called playbooks and these have plays inside them. Inside the different play, there are tasks that perform certain tasks. Puppet bolt script is called manifests, there are also tasks that can use most languages. Puppet bolt is also agentless that can be used for the same areas as ansible.

    Which tool is the most complicated? Which tool has the best performance? Are two questions that can determine which tool is best. To answer them, tests have been performed. We can see which tool is the most difficult to use and install. Which is the fastest and most efficient for the computer on which the tool is installed. The language that is the most complicated is also displayed.

    After these tests are completed, the results show that ansible is the most effective. Ansible is the fastest to complete the configuration. Ansible also has a less complicated installation. There are certain factors where the Puppet bolt is better. But the tests that Ansible was better at was the biggest factors. 

  • 249.
    Eriksson, Tommie
    et al.
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Damfelt, Christoffer
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Increasing Simulation Performance: Experimental tests of bottlenecks and scalability of LS-DYNA on Tetra Pak HPC-clusters2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Larger companies working with simulations and computing resources, require a lot of resources to execute their jobs. To make simulations less performance heavy, High-Performance Computing (HPC) is often used. HPC clusters implements a parallel algorithm over multiple nodes to speed up and utilize many computers, with this, large simulations that require a lot of resources will not take extensive amounts of time to finish.

    Large simulations can be performance heavy and time consuming and thus cost a lot of money if extra computing resources from outsourcing are needed. Optimizing HPC clusters can reduce extra costs while also decreasing the time it takes to execute jobs.

    With the cooperation of Packaging Material (PM), which is a business unit at Tetra Pak in Lund, Sweden, this thesis aims to understand Multi Parallel Processing (MPP) solvers, investigate Tetra Pak's HPC cluster to confirm that the right hardware and software is available and used as well as selecting and running representative simulation models and runtime parameters commonly used by PM, with the goal of optimizing their HPC clusters.

    Results given in this thesis are based on multiple tests which show that there are improvements that can be made, in both hardware and software. According to the findings in this thesis using newer versions and updated instructions for the processors a performance increase up to 17% is achievable.

  • 250.
    Erman, Evin
    University West, Department of Engineering Science.
    Robotiserad automation inom Prefabricering2023Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Industrial prefabrication of wooden houses is a technology that is constantly evolving. Sections are built in the factory and then transported to the construction site for assembly. The construction industry at large is dominated by many small and specialized subcontractors who are usually not technically proficient to embrace automation. The sector representing factory-built housing is an exception. Since the products are built in factories, the principles of mass production and mass customization apply as the norm for manufacturing. Mass production in factories is profitable to automate, but automation for mass customization is more difficult and requires new technology. Automation ensures quality in manufacturing. The prefabricated sections can be verified before they leave the factory, together with an optimal construction plan. Newer materials can be applied, tight tolerances achieved, while the built products are not affected by external climatic conditions, which is the case for sitebuilt housing. In order to estimate the needs of automation in the prefab sector, several automation technologies relevant to construction have been reviewed. The purpose of the literature review is to summarize the results of this study and provide an overview of the type of automation that is dominant in the industry. It will help the prefab industry to get a broader picture of building automation, while the research community gets a sense of the industry's "pull" in terms of automation.

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