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  • 351.
    Lexe, Lisa
    et al.
    University of Skövde, School of Engineering Science.
    Nilsson, Rebecca
    University of Skövde, School of Engineering Science.
    Identifiering av möjliga människa-robot samarbeten i monteringsindustrin2019Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Created by the University of Skövde and assigned by Elektroautomatik in Skövde this project was executed to identify possible HRC tasks in the assembly industry. The robots that were reviewed for this type of collaboration tasks were collaborative robots. Collaborative robots already exists in today’s industry but are commonly working on a co-existing level separated from the human. The type of collaboration investigated during this project regards solving tasks where the human and robot assist each other on a common work surface. This concept has gained more importance for companies today because of the increasing demand of a more flexible and adaptable system for the future production. Improvement proposals has been generated during the project regarding the collaborative robot and its implementation process.

    Based on the researched literature three interview protocols was created for three different groups of professions – assemblers, production technicians and engineers. In collaboration with companies in Skövde the interviews were executed gathering knowledge from people working within the assembly environment. The main question in all interview protocols were in which type of assembly tasks the interviewed could see a possibility for HRC. Collected data has been transcribed, structured and sorted in order to reach a result. Proposals of possible HRC operations gathered from the interviews were divided into six categories – inaccessible, time demanding, ergonomic relief, logistics, quality and product variety.

    A result has been presented where HRC tasks has been compiled from the interviews. These has been sorted into the six categories generated from possible HRC operations. General ideas were proposed during the interviews regarding what possible type of tasks and areas a collaborative robot could work together with a human. In many cases the proposals given could be sorted into more than one category – for example assemble of a large amount of screws that could be categorized as both ergonomic relief and time demanding. The category that generated the largest amount of proposals of HRC were tasks intended to offer ergonomic relief for the human.

    To identify more specific HRC tasks further research need to be performed based on the categories of areas that has been identified in this project. The future collaborative robot solution has to be able to combine more than one category to reach the flexible and adaptable system that is demanded. 

  • 352.
    Li, Cai
    et al.
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Bredies, Katharina
    Department of Design, Faculty of Textiles, Engineering and Business, University of Borås, Sweden.
    Lund, Anja
    Department of Textile Technology, Faculty of Textiles, Engineering and Business, University of Borås, Sweden.
    Nierstrasz, Vincent
    Department of Textile Technology, Faculty of Textiles, Engineering and Business, University of Borås, Sweden.
    Hemeren, Paul
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    k-Nearest-Neighbour based Numerical Hand Posture Recognition using a Smart Textile Glove2015In: AMBIENT 2015: The Fifth International Conference on Ambient Computing, Applications, Services and Technologies / [ed] MaartenWeyn, International Academy, Research and Industry Association (IARIA), 2015, p. 36-41Conference paper (Refereed)
    Abstract [en]

    In this article, the authors present an interdisciplinary project that illustrates the potential and challenges in dealing with electronic textiles as sensing devices. An interactive system consisting of a knitted sensor glove and electronic circuit and a numeric hand posture recognition algorithm based on k-nearestneighbour (kNN) is introduced. The design of the sensor glove itself is described, considering two sensitive fiber materials – piezoresistive and piezoelectric fibers – and the construction using an industrial knitting machine as well as the electronic setup is sketched out. Based on the characteristics of the textile sensors, a kNN technique based on a condensed dataset has been chosen to recognize hand postures indicating numbers from one to five from the sensor data. The authors describe two types of data condensation techniques (Reduced Nearest Neighbours and Fast Condensed Nearest Neighbours) in order to improve the data quality used by kNN, which are compared in terms of run time, condensation rate and recognition accuracy. Finally, the article gives an outlook on potential application scenarios for sensor gloves in pervasive computing.

  • 353.
    Lidberg, Simon
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Volvo Car Corporation, Sweden.
    Aslam, Tehseen
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Pehrsson, Leif
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Evaluating the impact of changes on a global supply chain using an iterative approach in a proof-of-concept model2018In: Advances in Manufacturing Technology XXXII: Proceedings of the 16th International Conference on Manufacturing Research, incorporating the 33rd National Conference on Manufacturing Research, September 11–13, 2018, University of Skövde, Sweden / [ed] Peter Thorvald, Keith Case, Amsterdam: IOS Press, 2018, p. 467-472Conference paper (Refereed)
    Abstract [en]

    Analyzing networks of supply-chains, where each chain is comprised of several actors with different purposes and performance measures, is a difficult task. There exists a large potential in optimizing supply-chains for many companies and therefore the supply-chain optimization problem is of great interest to study. To be able to optimize the supply-chain on a global scale, fast models are needed to reduce computational time. Previous research has been made into the aggregation of factories, but the technique has not been tested against supply-chain problems. When evaluating the configuration of factories and their inter-transportation on a global scale, new insights can be gained about which parameters are important and how the aggregation fits to a supply-chain problem. The paper presents an interactive proof-of-concept model enabling testing of supply chain concepts by users and decision makers.

  • 354.
    Lidberg, Simon
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Aslam, Tehseen
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Pehrsson, Leif
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Optimizing real-world factory flows using aggregated discrete event simulation modelling: Creating decision-support through simulation-based optimization and knowledge-extraction2019In: Flexible Services and Manufacturing Journal, ISSN 1936-6582, E-ISSN 1936-6590Article in journal (Refereed)
    Abstract [en]

    Reacting quickly to changing market demands and new variants by improving and adapting industrial systems is an important business advantage. Changes to systems are costly; especially when those systems are already in place. Resources invested should be targeted so that the results of the improvements are maximized. One method allowing this is the combination of discrete event simulation, aggregated models, multi-objective optimization, and data-mining shown in this article. A real-world optimization case study of an industrial problem is conducted resulting in lowering the storage levels, reducing lead time, and lowering batch sizes, showing the potential of optimizing on the factory level. Furthermore, a base for decision-support is presented, generating clusters from the optimization results. These clusters are then used as targets for a decision tree algorithm, creating rules for reaching different solutions for a decision-maker to choose from. Thereby allowing decisions to be driven by data, and not by intuition. 

  • 355.
    Lidberg, Simon
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Volvo Car Corporation, Skövde, Sweden.
    Pehrsson, Leif
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Frantzén, Marcus
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Applying Aggregated Line Modeling Techniques to Optimize Real World Manufacturing Systems2018In: Procedia Manufacturing, E-ISSN 2351-9789, Vol. 25, p. 89-96Article in journal (Refereed)
    Abstract [en]

    The application of discrete event simulation methodology in the analysis of higher level manufacturing systems has been limited due to model complexity and the lack of aggregation techniques for manufacturing lines. Recent research has introduced new aggregation methods preparing for new approaches in the analysis of higher level manufacturing systems or networks. In this paper one of the new aggregated line modeling techniques is successfully applied on a real world manufacturing system, solving a real-world problem. The results demonstrate that the aggregation technique is adequate to be applied in plant wide models. Furthermore, in this particular case, there is a potential to reduce storage levels by over 25 %, through leveling the production flow, without compromising deliveries to customers.

  • 356.
    Lidberg, Simon
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Pehrsson, Leif
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Using Aggregated Discrete Event Simulation Models and Multi-Objective Optimization to Improve Real-World Factories2018In: Proceedings of the 2018 Winter Simulation Conference / [ed] M. Rabe, A. A. Juan, N. Mustafee, A. Skoogh, S. Jain, B. Johansson, IEEE, 2018, p. 2015-2024Conference paper (Refereed)
    Abstract [en]

    Improving production line performance and identifying bottlenecks using simulation-based optimization has been shown to be an effective approach. Nevertheless, for larger production systems which are consisted of multiple production lines, using simulation-based optimization can be too computationally expensive, due to the complexity of the models. Previous research has shown promising techniques for aggregating production line data into computationally efficient modules, which enables the simulation of higher-level systems, i.e., factories. This paper shows how a real-world factory flow can be optimized by applying the previously mentioned aggregation techniques in combination with multi-objective optimization using an experimental approach. The particular case studied in this paper reveals potential reductions of storage levels by over 30 %, lead time reductions by 67 %, and batch sizes reduced by more than 50 % while maintaining the delivery precision of the industrial system.

  • 357.
    Lind, Carl Mikael
    et al.
    Unit of Occupational Medicine, Karolinska Institutet, Stockholm, Sweden / Division of Ergonomics, KTH Royal Institute of Technology, Huddinge, Sweden.
    Sandsjö, Leif
    Faculty of Caring Science, Work Life and Social Welfare, University of Borås, Sweden / Design & Human Factors, Department of Industrial and Materials Science, Chalmers University of Technology, Gothenburg, Sweden.
    Mahdavian, Nafise
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Hanson, Lars
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Scania CV, Södertälje, Sweden.
    Olivares, Jozé Antonio Diaz
    Division of Ergonomics, KTH Royal Institute of Technology, Huddinge, Sweden.
    Yang, Liyun
    Unit of Occupational Medicine, Karolinska Institutet, Stockholm, Sweden / Division of Ergonomics, KTH Royal Institute of Technology, Huddinge, Sweden.
    Forsman, Mikael
    Unit of Occupational Medicine, Karolinska Institutet, Stockholm, Sweden / Division of Ergonomics, KTH Royal Institute of Technology, Huddinge, Sweden.
    Prevention of Work: Related Musculoskeletal Disorders Using Smart Workwear – The Smart Workwear Consortium2019In: Human Systems Engineering and Design: Proceedings of the 1st International Conference on Human Systems Engineering and Design (IHSED2018): Future Trends and Applications, October 25-27, 2018, CHU-Université de Reims Champagne-Ardenne, France / [ed] Tareq Ahram, Waldemar Karwowski, Redha Taiar, Springer, 2019, Vol. 876, p. 477-483Conference paper (Refereed)
    Abstract [en]

    Adverse work-related physical exposures such as repetitive movements and awkward postures have negative health effects and lead to large financial costs. To address these problems, a multi-disciplinary consortium was formed with the aim of developing an ambulatory system for recording and analyzing risks for musculoskeletal disorders utilizing textile integrated sensors as part of the regular workwear. This paper presents the consortium, the Smart Workwear System, and a case study illustrating its potential to decrease adverse biomechanical exposure by promoting improved work technique. 

  • 358.
    Lindblom, Jessica
    et al.
    University of Skövde, The Informatics Research Centre. University of Skövde, School of Informatics.
    Siewertz, Josefine
    University of Skövde, The Informatics Research Centre. University of Skövde, School of Engineering Science.
    Challenges and lessons learned concerning learning in a social context in web-based education2014In: Next Generation Learning Conference, NGL 2014: Conference Summary / [ed] Erik Brunnert Walfridsson, Falun: Högskolan Dalarna, 2014, p. 27-41Conference paper (Other academic)
    Abstract [sv]

    This paper presents five identified challenges concerning learning in a social context in web-based education and discusses lessons learned on how to reduce these challenges in higher education. The study is primarily based on the authors’ own experiences in conducting web-based education as well as on theories and research on learning and e-learning.

  • 359.
    Lindblom, Jessica
    et al.
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Thorvald, Peter
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Manufacturing in the wild: viewing human-based assembly through the lens of distributed cognition2017In: Production & Manufacturing Research, ISSN 2169-3277, Vol. 5, no 1, p. 57-80Article in journal (Refereed)
    Abstract [en]

    The interdisciplinary field of cognitive science has been and isbecoming increasingly central within human factors and ergonomics(HF&E) and, since at the same time, there has long been a call for a more systems perspective in the area with a somewhat wider unit of analysis. This paper argues that the theoretical framework of distributed cognition would greatly benefit the application of HF&E to manufacturing and would offer a more holistic understanding of the interactions between different entities within a greater context,including the social, cultural and materialistic. We aim to characterize and analyse manufacturing as a complex socio-technical system from a distributed cognition perspective; focusing on the use, mediation and integration of different forms of representations, tools and artefacts in this domain. We present illustrative examples fromauthentic manual assembly, showing the cognitively distributed nature of the work, ranging from scaffolding strategies of the individual worker to the emergent properties of a whole assembly line. The paper further proposes and provides benefits of using a distributed cognition framework as a novel approach in the toolboxfor the HF&E discipline, where it may have been found before, but the application to manufacturing has been absent.

  • 360.
    Lindblom, Jessica
    et al.
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Thorvald, Peter
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Towards a framework for reducing cognitive load in manufacturing personnel2014In: Advances in Cognitive Engineering and Neuroergonomics / [ed] Kay Stanney & Kelly S. Hale, AHFE , 2014, p. 233-244Conference paper (Refereed)
    Abstract [en]

    The interest in cognitive aspects of human performance has dramatically increased in recent years in manufacturing, complementing the area of physical ergonomics, and the expanded focus on cognitive aspects may offer significant insights and contributions to industrial domains. A considerably increased interest has been directed at the role and effects cognitive load has on human performance, and ultimately on production outcome. The main question addressed is: How can an understanding of cognitive load in manufacturing lead us to design better workplaces for the personnel at the shop floor? To answer this question, we have to consider how technology interacts with work environment and with human cognition from a systems perspective. Technology should be considered a resource in the design of a better working environment, aid those activities for which we are poorly suited cognitively, and enhance those cognitive skills for which we are ideally suited. This has resulted in a potential framework of factors that might have impact on high cognitive load, consisting of three levels; internal factors, external factors, and activity space. The initial framework focuses primarily on the former factors, identifying risks where a high cognitive load might lead to difficulty of work, negatively affecting production outcome.

  • 361.
    Lindblom, Jessica
    et al.
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Wang, Wei
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Towards an Evaluation Framework of Safety, Trust, and Operator Experience in Different Demonstrators of Human-Robot Collaboration2018In: Advances in Manufacturing Technology XXXII: Proceedings of the 16th International Conference on Manufacturing Research, incorporating the 33rd National Conference on Manufacturing Research, September 11–13, 2018, University of Skövde, Sweden / [ed] Peter Thorvald, Keith Case, Amsterdam: IOS Press, 2018, p. 145-150Conference paper (Refereed)
    Abstract [en]

    Advancements in human-robot collaboration (HRC) are regarded as major aspects of the future Industry 4.0. HRC entails humans that cooperatively work with robots in dynamic, changing, and unpredictable settings where they should assist and learn from each other and automatically respond to changes. This requires research and development to investigate and evaluate how these hybrid collaborative systems should function and distribute work. The common practice is to focus on performance-related issues, which are highly influenced by human factors (HF). Because of the prevailing orientation towards HF, HRC runs the risk of not considering the modern understandings of human cognition and technology-mediated activity, in which humans are considered as actors (not factors) in a socio-material context. Although HF is dominant and well justified, the problem is that it may hinder general development, because it is not aligned with the modern understanding of cultivating a safety culture that promotes continuous improvements and development as an inherent attitude of companies and work practices. Taking an opposite approach, where the human operators working together with robots are playing active and positive roles in constructing safety, trust, and good operator experience. Hence, the collaborative human-robot system perspective addresses the need to develop and assess new evaluation methods that consider aspects like safety, trust, and operator experience from modern understandings of human cognition and technology-mediated activity, where also different levels of in human-robot collaboration have to be considered. This paper presents 1) the initial conceptual framework of HRC that addresses these above issues. It also describes 2) the design of a comparative analysis and benchmarking tasks of operators when interacting closely with robots, in three different demonstrators of varying levels of collaboration. The final outcome from this work should, in the long run, function as a roadmap for successful implementation of HRC in industry.

  • 362.
    Lindell Wallgren, Ida
    University of Skövde, School of Engineering Science.
    Alternativt material i behållare för konstgödselrampspridare: Förarbete för prototyp2015Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Överums Bruk AB manufactures agricultural equipment such as the fertilizer spreader Wing Jet. Wing Jet has a container which today is manufactured from stainless steel and the company wishes to know if it is possible and suitable to manufacture the container from plastic/plastic composite with the purpose to lessen the containers production costs and weight. This work is limited to the container, the rest of the fertilizer spreader should not need any changes to switch the stainless steel container for a plastic/plastic composite one and the work does not include manufacturing a prototype. Rotational molding and hand lay-up (glass-fibre reinforcement) are two manufacturing processes which are suitable to use when manufacturing such large objects. Simulations of a rotational molded container in the material high density polyethylene (HDPE) in the program SolidWorks Simulation Standard results in maximum effective stresses just above the materials tensile strength when a pressure based on equations from the European standard Eurocode 1-4: 2006 (Silos and Tanks) are applied on the containers inside. However, deformations of several centimeters occurs which in itself is not a problem, though it makes the container less esthetically appealing (smooth sides bulges outward). The containers weight decreases to approximately half of that of today and it is cheaper to manufacture. Materials and manufacturing processes which results in a container with higher stiffness in the purpose of lessen the deformation is recommended to investigate as future work. Examples of this are glass-fibre reinforced polyester or epoxy and “sandwich”-constructions. A sandwich-construction is comprised of two (or more) layers of a material with a core, of e.g. foam, between. The simulations carried out are linear elastic, whereas plastics generally are non-linear, so non-linear simulations should be carried out before a prototype in manufactured.

  • 363.
    Linder, Jonas
    University of Skövde, School of Engineering Science.
    Kyleffektivisering av en havsvattenanläggning: Havets Hus i Lysekil2016Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Havets Hus i Lysekil bedriver en anläggning med ett flertal havsvattenakvarium som innehåller fiskar och havsdjur från svenska havsvatten. Till anläggningen tas det kontinuerligt in nytt havsvatten från Gullmarsfjorden, till några av akva-rierna kyls det inkommande havsvattnet med hjälp av en kylmaskin. I dagsläget är kylmaskinen luftkyld, vilket är ineffek-tivt. Havets Hus vill undersöka möjligheten att effektivisera kylprocessen genom att kyla maskinen mer effektivt, undersö-ka om det går att ta vara på värmeenergin som annars släpps ut i luften eller på något annat sätt göra kylprocessen mer effektiv.Sex alternativ för effektivare kylning har tagits fram. Det finns två inriktningar på alternativen, antingen att förbättra den befintliga installationen genom att till exempel kyla dess kondensor mer effektivt med hjälp utav havsvatten eller att installera nya maskiner. Det finns också ett kompletteringsalternativ som går att kombinera med alla de andra alternativen och går ut på att installera en värmeväxlare mellan ingående havsvatten som ska kylas och utgående havsvatten från de kylda akvarierna. Alternativet som ger störst ekonomisk sparpotential går ut på att installera två nya kylmaskiner. En som är dimensionerad efter Havets Hus varmvattenbehov och som tar värme från det inkommande havsvattnet och en som fyller upp det resterande kylbehovet. De nya maskinerna fyller det totala kylbehovet på Havets Hus, det vill säga både kylbehovet för det inkommande havsvattnet och för ventilationssystemet. Alternativet kan spara Havets Hus ca 184 000-199 000 kr/år och tillsammans med en värmeväxlare kan det spara ca 202 000-223 000 kr/år.

  • 364.
    Lindström, Adam
    University of Skövde, School of Engineering Science.
    Undersökning av mekanisk belastning på ytmonterade elektriska komponenter vid screentryckning2016Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    A study is done to find out if there is any risk to damage surface mounted components with the use of pneumatic supports during screen printing. The literature review suggests that there is only one type of component that is relevant to analyze: MLCC (multilayered ceramic chip capacitor). It is also pointed out that bending of the PCB (Printed Circuit Board) on which the MLCC is mounted may cause it to crack.

    For the load case that is present during screen printing, the deflection of the PCB is analyzed using two methods: First an analytical method for beam on elastic foundation and second: FEM (Finite Element Method) with discrete springs as support. For these calculations the size of the PCB is set to have the dimensions 100x40x1.6 mm. According to the analytical method the PCBs deflection is 0.6 mm and the FEM 0.7 mm. The difference in deflection is because the analytical method assumes that the elastic foundation is evenly spread while for the FEM the supports are idealized as discrete springs.

    The stress in the MLCC as a result of the PCB bending has been calculated both analytically and with FEM. The analytical solution is based on beam theory and the MLCC is assumed to deform equally to the PCB. In the FEM analysis, the solder joint is also considered. The analytical calculations result in very large stresses within the MLCC (705 MPa) which is due to the assumptions made that the MLCC deforms equally to the PCB. In reality, the solder joint also deforms which dampens the stresses in the MLCC. This is why the FEM analysis gives a more realistic result and the stress is calculated to 37 MPa.

    The conclusion of this study is that the pneumatic supports can be used without risk of damaging surface mounted components.

  • 365.
    Linero Jiménez, Adriano
    University of Skövde, School of Engineering Science.
    DEVELOPMENT OF A MODEL OF THE DEGRADATION OF THE MECHANICAL PROPERTIES OF POLYOXYMETHYLENE (POM) IN THE PRESENCE OF BIODIESEL2014Independent thesis Advanced level (degree of Master (One Year)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    This project analyses the impact in the mechanical properties of Polyoxymethylene (POM) of three different blends of biodiesels: B0 with 0% of Rapeseed Methyl-ester (RME), B20 with 20% of RME and B100 with 100% of RME. Polyoxymethylene specimens have been subjected to an accelerated aging during 1600 hours at 85ºC. This is the equivalent to 20 years of life time. In addition, a thermal oxidation in air at the same temperature has been performed to check the impact of the temperature in the final degradation.Three different methods have been performed to calculate the diffusion rate, however and one of them has been selected for its reliable results. The second Fick´s law have been chosen to model the diffusion. The diffusion rate has been calculated for the B20 and B100 blend due to the B0 blend has a non-constant diffusion rate. B20 shows also some divergence while B100 fits the Fickian behaviour.A Finite Different approximation method has been used to predict the concentration profiles of the diffusion process of B20 blend. They have been compared with the results of the IR Microscope, with a clear misalignment between the expected and the actual values.Tensile tests have been done in different stages of the test to check the stress-strain behaviour of the specimens for each aging type. The most relevant parameter of degradation is the Elongation At Break (EAB), which decrease considerably a cause of the embrittlement. A study of the real stress-strain has been also done to assure the real behaviour of the material.A fracture surface study through Scanning Electron Microscope (SEM) and Light Microscope has been done to assure the brittle behaviour with the aging and the changes in the structure of the material.The swelling behaviour has been also modelled, and the bases for a future FEM analysis have been exposed.

  • 366.
    Lingman, Simon
    et al.
    University of Skövde, School of Engineering Science.
    Einemo Swahn, Dennis
    University of Skövde, School of Engineering Science.
    Utveckla förbättringsunderlag och utöka utnyttjandegraden för en maskincell2019Independent thesis Basic level (university diploma), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete är utfört på RPC Superfos i Mullsjö och företaget tillverkar plastförpackningar till livsmedelsprodukter runtom i världen. RPC Superfos har ett uppsatt mål att det sammanlagda TAK/OEE-värdet för samtliga maskiner inte skall understiga 76,4 %. I dagsläget ligger många av maskincellerna på ett TAK/OEE-värde över målet, medan vissa ligger under 50 % vilket innebär att målet inte uppnås. Den maskincell som omfattas för projektet har lägst TAK/OEE-värde av samtliga maskinceller i fabriken. Syftet har varit att undersöka varför denna maskin inte uppnår företagets mål med ett TAK/OEE värde på 76,4 %. Efter att ha analyserat data över maskincellens stopp konstaterades att den bidragande orsaken till det låga TAK/OEE-värdet beror på ställtiden. Utifrån detta konstaterande har flera arbetsmetoder som frekvensstudier, intervjuer, SMED och spaghettidiagram använts för att presentera förbättringsförslag. Just ställtiden har valts som ett delmål för att fortsätta processen och genom en överenskommelse med företaget valdes att försöka reducera ställtiden från mediantiden 12h till 7h och detta skulle motsvara 42 % av den totala ställtiden på maskincellen. Metodvalen som tidigare nämnts beskrivs i referensramen och detta har gynnat det fortsatta arbetet med att försöka reducera ställtiden och därmed öka tillgängligheten för maskincellen. Under sju omställningar användes Genchi Genbutsu som arbetsmetod för att skapa en ökad förståelse över processen. Under samtliga omställningarsamlades data in med arbetsmetoden frekvensstudie där ställarnas aktiviteter kategoriserades för att identifiera beläggningen för varje aktivitet. Slutligen användes arbetsmetoden spaghettidiagram för att analysera och dokumentera ställarnas rörelser. 19 förbättringsförslag presenterades för personal på RPC Superfos, 10 utav förbättringsförslagen användes under en avslutande omställning. Resultatet från den avslutande omställningen jämfördes emot mediantiden för en omställning. Resultatet blev att omställningen tog 5 timmar, 10 minuter och 14 sekunder, vilket innebär en procentuell minskning av omställningstiden med 57,5%

  • 367.
    Linnéusson, Gary
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Towards strategic development of maintenance and its effects on production performance: A hybrid simulation-based optimization framework2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Managing maintenance in manufacturing within an economical short-termism framework and taking the consequential long-term cost effects into account is hard. The increasing complexity of managing maintenance and its impact on the business results calls for more advanced methods to support long-term development through effective activities in the production system environment. This problem-based design science research has evolved into the novel concept of a hybrid simulation-based optimization (SBO) framework which integrates multi-objective optimization (MOO) with system dynamics (SD) and discrete-event simulation (DES) respectively. The objective is to support managers in their decision-making on the strategic and operational levels for prioritizing activities to develop maintenance and production performance.

    To exemplify the hybrid SBO framework this research presents an SD model for the study of the dynamic behaviors of maintenance performance and costs, which aims to illuminate insights for the support of the long-term strategic development of maintenance practices. The model promotes a system view of maintenance costs that includes the dynamic consequential costs as the combined result of several interacting maintenance levels throughout the constituent feedback structures. These levels range from the applied combination of maintenance methodologies to the resulting proactiveness in production, such as the ratio between planned and unplanned downtime, in continuous change based on the rate of improvements arising from root-cause analyses of breakdowns. The model creation and validation process have been supported by two large maintenance organizations operating in the Swedish automotive industry. Experimental results show that intended changes can have both short-term and longterm consequences, and that the system may show both obvious and hidden dynamic behavioral effects.

    The application of MOO distinguishes this work from previous research efforts that have mixed SD and DES. It presents a unique methodology to support more quantitative and objective-driven decision making in maintenance management, in which the outcome of an SD+MOO strategy selection process forms the basis for performance improvements on the operations level. This is achieved by framing the potential gains in operations in the DES+MOO study, as a result of the applied strategy in the SD model. All in all, this hybrid SBO framework allows pinpointing maintenance activities based on the analysis of the feedback behavior that generates less reactive load on the maintenance organization.

  • 368.
    Linnéusson, Gary
    et al.
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Engineering Science.
    Aslam, Tehseen
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Engineering Science.
    Machine Strategy Evaluation Using Group Model Building in System Dynamics2014In: System Dynamics Society: Proceedings of the 32nd International Conference of the System Dynamics Society / [ed] Pål Davidsen and Etiënne A. J. A. Rouwette, 2014, p. 24 s.-Conference paper (Refereed)
    Abstract [en]

    Modeling projects, in order to build richer understanding of the dynamics of real-world

    phenomena in manufacturing systems, benefit from utilizing System dynamics group model

    building. This paper describes a project utilizing such method in order to identify the

    interrelated dynamics of aging machinery equipment, competence development, and level of

    automation for accurate manufacturing systems development. These central aspects were

    identified by the project group during modeling and were considered vital in order to

    approach the proper Machine Strategy for the system of interest. Aspects of attention in the

    study also considered participants’ learning of the system of interest, participants’

    perception upon model results, and the comparison between utilizing group model building

    and the traditional modeler-client approach. It is shown that System dynamics group model

    building has potential use in manufacturing, and indeed that more efforts are needed for

    successful use in projects. For that reason the need of a framework for supporting system

    dynamics projects in manufacturing is identified.

  • 369.
    Linnéusson, Gary
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Galar, Diego
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Wickelgren, Mikael
    University of Skövde, School of Business. University of Skövde, Enterprises for the Future.
    A path forward: Systems thinking maintenance as part of shift in mind on added value2015In: / [ed] Sulo Lahdelma & Kari Palokangas, 2015Conference paper (Refereed)
    Abstract [en]

    Abstract: The purpose and novelty with this recently started research is the introduction of a modelling concept that aims to include the interdependencies maintenance have with financial figures, customer behavior, and production, using systems thinking. It suggests on a path forward in acknowledging short- and long term effects from maintenance on the production system and its financial results. Using systems thinking modelling enables learning on consequences from strategies and policies on the studied system; enabling evaluation of future scenarios supporting decision makers in defining sustainable strategies of action on the policy-level. This paper provides a brief outline of the thoughts behind the research project and points the direction for future research by first introducing aspects regarding the problem and possibilities to address, then briefly introduce different modelling approaches that in part address the problem, which is summarized into a path forward, and finally includes an example of a model by the author of a machine strategy problem that connects the physical assets and actions with financial costs.

  • 370.
    Linnéusson, Gary
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Galar, Diego
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Luleå University of Technology, Luleå, Sweden.
    Wickelgren, Mikael
    University of Skövde, School of Business. University of Skövde, Enterprises for the Future.
    In Need for Better Maintenance Cost Modelling to Support the Partnership with Manufacturing2016In: Current Trends in Reliability, Availability, Maintainability and Safety: An Industry Perspective / [ed] Uday Kumar, Alireza Ahmadi, Ajit Kumar Verma & Prabhakar Varde, Springer, 2016, 1, p. 263-282Conference paper (Other academic)
    Abstract [en]

    The problem of maintenance consequential costs has to be dealt with in manufacturing and is core of this paper. The need of sustainable partnership between manufacturing and maintenance is addressed. Stuck in a best practice thinking, applying negotiation as a method based on power statements in the service level agreement, the common best possible achievable goal is put on risk. Instead, it may enforce narrow minded sub optimized thinking even though not intended so. Unfortunately, the state of origin is not straightforward business. Present maintenance cost modelling is approached, however limits to its ability to address the dynamic complexity of production flows are acknowledged. The practical problem to deal with is units put together in production flows; in which downtime in any unit may or may not result in decreased throughput depending on its set up. In this environment accounting consequential costs is a conundrum and a way forward is suggested. One major aspect in the matter is the inevitable need of shift in mind, from perspective thinking in maintenance and manufacturing respectively towards shared perspectives, nourishing an advantageous sustainable partnership.

  • 371.
    Linnéusson, Gary
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Aslam, Tehseen
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Engineering Science.
    Investigating Maintenance Performance: A Simulation Study2016In: Proceedings of the 7th Swedish Production Symposium, 2016Conference paper (Refereed)
    Abstract [en]

    Maintenance can be performed in multiple procedures, and it is hard to justify investments in preventive work. It is a complex equation between the inherent complexity of maintenance and its tight dependencies with production, but also the aspect of direct cost and consequential costs from activities. A model is presented that quantify dynamics of maintenance performance in order to enable a systems analysis on the total of consequences from different strategies. Simulation offers experimenting and learning on how performance is generated. The model is based on parts of previous research on maintenance modelling, system dynamics, maintenance theory, and mapping of practical information flows in maintenance. Two experiments are presented that both take off from a reactive strategy of maintenance performance, and implement two different strategies for preventive maintenance. Using the model enriches the analysis on how the aspects of maintenance performance work together with different maintenance strategies.

  • 372.
    Linnéusson, Gary
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Aslam, Tehseen
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    A hybrid simulation-based optimization framework for supporting strategic maintenance to improve production performance2020In: European Journal of Operational Research, ISSN 0377-2217, E-ISSN 1872-6860, Vol. 281, no 2, p. 402-414Article in journal (Refereed)
    Abstract [en]

    Managing maintenance and its impact on business results is increasingly complex, calling for more advanced operational research methodologies to address the challenge of sustainable decision-making. This problem-based research has identified a framework of methods to supplement the operations research/management science literature by contributing a hybrid simulation-based optimization framework (HSBOF), extending previously reported research.

    Overall, it is the application of multi-objective optimization (MOO) with system dynamics (SD) and discrete-event simulation (DES) respectively which allows maintenance activities to be pinpointed in the production system based on analyzes generating less reactive work load on the maintenance organization. Therefore, the application of the HSBOF informs practice by a multiphase process, where each phase builds knowledge, starting with exploring feedback behaviors to why certain near-optimal maintenance behaviors arise, forming the basis of potential performance improvements, subsequently optimized using DES+MOO in a standard software, prioritizing the sequence of improvements in the production system for maintenance to implement.

    Studying literature on related hybridizations using optimization the proposed work can be considered novel, being based on SD+MOO industrial cases and their application to a DES+MOO software.

  • 373.
    Linnéusson, Gary
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Aslam, Tehseen
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Justifying Maintenance Studying System Behavior: A Multipurpose Approach Using Multi-objective Optimization2017In: 35th International Conference of the System Dynamics Society 2017: Cambridge, Massachusetts, USA 16 - 20 July 2017 / [ed] J. Sterman, N. Repenning, Curran Associates, Inc., 2017, Vol. 2, p. 1061-1081Conference paper (Refereed)
    Abstract [en]

    Industrial maintenance includes rich internaldynamic complexity on how to deliver value. While the technical development hasprovided with applicable solutions in terms of reliability and condition basedmonitoring, managing maintenance is still an act of balancing, trying to pleasethe short-termism from the economic requirements and simultaneously address thenecessity of strategic and long-term thinking. By presenting an analysis tojustify maintenance studying system behavior, this paper exemplifies thecontribution of the combined approach of a system dynamics maintenanceperformance model and multi-objective optimization. The paper reveals howinsights from the investigation, of the near optimal Pareto-front solutions inthe objective space, can be drawn using visualization of performance ofselected parameters. According to our analysis, there is no return back to thesingle use of system dynamics; the contribution to the analysis of exploringsystem behavior, from applying multi-objective optimization, is extensive.However, for the practical application, the combined approach is not areplacement – but a complement. Where the interpretation of the visualizedPareto-fronts strongly benefits from the understanding of the model dynamics, inwhich important nonlinearities and delays can be revealed, and thus facilitateon the selected strategical path for implementation.

  • 374.
    Linnéusson, Gary
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Jönköping University, School of Engineering, Sweden.
    Aslam, Tehseen
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Quantitative analysis of a conceptual system dynamics maintenance performance model using multi-objective optimisation2018In: Journal of Simulation, ISSN 1747-7778, E-ISSN 1747-7786, Vol. 12, no 2, p. 171-189Article in journal (Refereed)
  • 375.
    Linnéusson, Gary
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Jönköping University, Sweden.
    Aslam, Tehseen
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Relating strategic time horizons and proactiveness in equipment maintenance: a simulation-based optimization study2018In: Procedia CIRP, ISSN 2212-8271, E-ISSN 2212-8271, Vol. 72, p. 1293-1298Article in journal (Refereed)
    Abstract [en]

    Identifying sustainable strategies to develop maintenance performance within the short-termism framework is indeed challenging. It requires reinforcing long-term capabilities while managing short-term requirements. This study explores differently applied time horizons when optimizing the tradeoff between conflicting objectives, in maintenance performance, which are: maximize availability, minimize maintenance costs, and minimize maintenance consequence costs. The study has applied multi-objective optimization on a maintenance performance system dynamics model that contains feedback structures that explains reactive and proactive maintenance behavior on a general level. The quantified results provide insights on how different time frames are conditional to enable more or less proactive maintenance behavior in servicing production.

  • 376.
    Linnéusson, Gary
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Aslam, Tehseen
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Towards strategic development of maintenance and its effects on production performance by using system dynamics in the automotive industry2018In: International Journal of Production Economics, ISSN 0925-5273, E-ISSN 1873-7579, Vol. 200, p. 151-169Article in journal (Refereed)
    Abstract [en]

    Managing maintenance within an economical short-termism framework, without considering the consequential long-term cost effect, is very common in industry. This research presents a novel conceptual system dynamics model for the study of the dynamic behaviors of maintenance performance and costs, which aims to illuminate insights for the support of the long-term, strategic development of manufacturing maintenance. By novel, we claim the model promotes a system's view of maintenance costs that include its dynamic consequential costs as the combined result of several interacting maintenance levels throughout the constituent feedback structures. These range from the applied combination of maintenance methodologies to the resulting proactiveness in production, which is based on the rate of continuous improvements arising from the root cause analyses of breakdowns. The purpose of using system dynamics is to support the investigations of the causal relationships between strategic initiatives and performance results, and to enable analyses that take into consideration the time delays between different actions, in order to support the sound formulation of policies to develop maintenance and production performances. The model construction and validation process has been supported by two large maintenance organizations operating in the Swedish automotive industry. Experimental results show that intended changes can have both short and long-term consequences, and that obvious and hidden dynamic behavioral effects, which have not been reported in the literature previously, may be in the system. We believe the model can help to illuminate the holistic value of maintenance on the one hand and support its strategic development as well as the organizational transformation into proactiveness on the other.

  • 377.
    Liu, Yu
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Syberfeldt, Anna
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Strand, Mattias
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    A Review of Simulation Based Life Cycle Assessment in Manufacturing Industry2018In: Advances in Manufacturing Technology XXXII: Proceedings of the 16th International Conference on Manufacturing Research, incorporating the 33rd National Conference on Manufacturing Research, September 11 – 13, 2018, Skövde, Sweden / [ed] Peter Thorvald, Keith Case, Amsterdam, Berlin, Washington,DC: IOS Press, 2018, Vol. 8, p. 381-386Conference paper (Refereed)
    Abstract [en]

    The manufacturing industry has a duty to minimize their environmental impact and more and more legislations include environmental impact evaluations from a life cycle perspective to avoid burden shift. Current manufacturing industry increase their use of computer-based simulations for optimizing production processes. In recent years, a number of studies have been published, combining simulations with life cycle assessments (LCA), to evaluate and minimize the environmental impact of production activities, as part of improving the production processes. Still, current knowledge concerning simulations for LCA is rather scattered. Therefore, this paper reviews relevant literature covering simulation based LCA for production development. The results of the review and cross comparison of papers are structured following the 6 categories in line with the ISO standard definition of LCA (goal formulation, scope definition, environmental impact assessment, data quality, level of modelling details, and model validation) and report the strengths and constraints of the reviewed studies. 

  • 378.
    Liu, Yu
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Syberfeldt, Anna
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Strand, Mattias
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Review of simulation-based life cycle assessment in manufacturing industry2019In: Production & Manufacturing Research, ISSN 2169-3277, Vol. 7, no 1, p. 490-502Article in journal (Refereed)
    Abstract [en]

    The manufacturing industry has a duty to minimize its environmental impact, and an increasing body of legislation mandates environmental impact evaluations from a life cycle perspective to prevent burden shift. The manufacturing industry is increasing its use of computer-based simulations to optimize production processes. In recent years, several published studies have combined simulations with life cycle assessments (LCAs) to evaluate and minimize the environmental impact of production activities. Still, current knowledge of simulations conducted for LCAs is rather disjointed. This paper accordingly reviews the literature covering simulation-based LCAs of production processes. The results of the review and cross-comparison of papers are structured in terms of seven elements in line with the ISO standard definition of LCA and report the strengths and limitations of the reviewed studies. © 2019, © 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.

  • 379.
    Liu, Yu
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Syberfeldt, Anna
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Urenda Moris, Matías
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Jägstam, Mats
    Jönköping University, School of Engineering, Jönköping, Sweden.
    Jenny, Everbring
    Volvo Group, Advanced Technology & Research, Gothenburg, Sweden.
    Kloo, Henrik
    Volvo Group, Advanced Technology & Research, Gothenburg, Sweden.
    Evaluating environmental impacts of production process by simulation based life cycle assessment2016In: Proceedings of the 7th Swedish Production Symposium, 2016Conference paper (Refereed)
    Abstract [en]

    Historically, the manufacturing industry is one of the main contributors to the environmental issues. With conservation of the environment becoming more and more critical for survival, it is of importance for the manufacturing industry to take responsibility for minimizing their productions’ environmental impacts. Life cycle assessment has been widely used in the product’s development phase within the manufacturing industry. However, the environmental impacts that come from various dynamic manufacturing processes are only estimated with large uncertainty. Some studies have suggested that the combination of life cycle assessment and production flow simulation is an appropriate approach to address the environmental impacts from the manufacturing processes. Nevertheless, these studies are often limiting their concerns to the limited life cycle phases or certain environmental impacts. This study proposes a framework regarding how to develop a method for evaluating and identifying improvements that help reduce the life-cycle environmental impacts of complex production processes. In addition, this work employs a simplified case study to demonstrate the proposed framework. 

  • 380.
    Lorente Zamora, Joanes
    et al.
    University of Skövde, School of Engineering Science.
    Sorarrain Aguirrezabala, Gorka
    University of Skövde, School of Engineering Science.
    Modelling and emulation of industrial electric, pneumatic and hydraulic system2018Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In recent years, the University of Skövde (HiS) is carrying an advance research in Virtual Commissioning and Emulation. The main goal of the research is to test and verify the control logic of an industrial system virtually before implementing it in the real industry. Literature shows how higher modeling detail level is needed taking into account aspects such as geometry, kinematic, behavior and interfaces. That makes an interesting branch of research for the university and that is the reason why the university is focusing on creating models in component level, where a complete emulation data model is being expanded. The aim of this thesis is to develop a way of modelling electric, hydraulic and pneumatic connections in order to create independent models that can be connected between them for creating systems. Furthermore, an energetic analysis of the system has been done. In the first part of the thesis, a frame of reference and a literature review has been done in order to learn about the fields that the authors are going to work. After that, the simulation models of different electric, pneumatic and hydraulic components have been created with a method, inspired by the producer/consumer concept, which provides a generic solution that allows energy flow in different domains between components in a simple way. Then, different component simulation models have been connected in order to emulate more complex systems. Once the models are done, there have been some test in order to know if all perform as expected. Finally, a discussion of the failures which have been during the project have been done. The experiments done have shown that the proposed and then implemented system has fulfilled all the objectives, unlocking the next step of the emulation development.

  • 381.
    Lundberg, Anna
    et al.
    University of Skövde, School of Engineering Science.
    Oldenburg, Martina
    University of Skövde, School of Engineering Science.
    Utveckling av golvkonsol för elbil2017Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A product development project has been carried out at University of Skövde in collaboration with China Euro Vehicle Technology AB (CEVT). CEVT works with research and development in the automotive industry and is owned by Geely Auto. With current trends towards developing full electric cars, CEVT wanted to explore how the space between the two front seats could be dispensed, with no handbrake or gearshift. The aim of the thesis was to develop a floor console for an electric car adapted to the Chinese market and the company's requirements.

    The project began with a pre study which included interviews with the target group and experts as well as a market research. The pre study studied user needs and different car interiors. The information was compiled in a requirement specification together with demands from the company. Concepts were generated based on future trends and identified functions and then evaluated in several steps. The concept has been evaluated with the company, through ergonomic simulation and a user test with a full-scale prototype. The result is designed in two levels, the top focuses on technology where a charging station is placed as well as an interaction area for the dashboard the base is instead focused on storage. The result contains different storage solutions customized and developed for the user and their belongings. The floor console is designed with focus on flexibility, functionality and adjustability as parts can be moved and replaced. The armrest and top can also be adjusted according to different needs.

  • 382.
    Lundberg, Jesper
    et al.
    University of Skövde, School of Engineering Science.
    Mehtonen, Ronja
    University of Skövde, School of Engineering Science.
    Utvärdering och analys av batchstorlekar, produktsekvenser och omställningstider2015Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Volvo GTO is one of the strongest brands in the truck industry, with a long and proud history of world-leading innovations. The factory in Skövde produces diesel engines of various sizes to Volvo GTO. The project has been carried out on the processing part of grovdel crankshaft. Where the objective was to construct a simulation model that reflects flows 0, 1 and 2 on the crankshaft grovdel order to produce the best driving style for the size of the batches and sequences, focusing on PIA, between the stock and conversion-up times. A theoretical study intervention gave knowledge to the methodology to ensure that the data is collected and processed correctly. The data were collected in an Excel document, which was integrated with the simulation model for an overview and adjustments would be possible.

    The simulation program, Siemens Plant Simulation 12 used in the construction of the complex model of the three flows, which where verified and validated against the real flows. Optimization on the simulation model was made with a high and a low demand for crankshafts. Several objects were taken into consideration as: minimal waiting processing Findel, minimal setup time and minimal total-PIA from a truly viable perspective. The optimization showed a possible production planning in order to best be able to run such large batches as possible with reduced readjustment time and for delays of production in processing rawflows to not occur in the refined flow. For maximum capacity in the company there are two different optimal solutions one solution focused on reducing setup time and the second solution to minimize the number of additional production hours per week.

    Discrete simulation of production flows are being used to support production planning and simulation model is created for the continued use of the Volvo GTO, either in simulation group or future researches and theses in collaboration with the University of Skövde. The project objectives were achieved with good results and resulted as a standing basis for future planning of batches and sequences of processing crankshaft Volvo GTO.

  • 383.
    López De La Cova Trujillo, Miguel Angel
    et al.
    University of Skövde, School of Engineering Science. miguelopeztru@gmail.com.
    Bertilsson, Niklas
    University of Skövde, School of Engineering Science. niklasbertilsson.68@gmail.com.
    Investigation of the workforce effect of an assembly line using multi-objective optimization2016Independent thesis Basic level (university diploma), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    ABSTRACT

    The aim of industrial production changed from mass production at the beginning of the 20th century. Today, production flexibility determines manufacturing companies' course of action. In this sense, Volvo Group Trucks Operations is interested in meeting customer demand in their assembly lines by adjusting manpower. Thus, this investigation attempts to analyze the effect of manning on the main final assembly line for thirteen-liter heavy-duty diesel engines at Volvo Group Trucks Operations in Skövde by means of discrete-event simulation.

    This project presents a simulation model that simulates the assembly line. With the purpose of building the model data were required. One the one hand, qualitative data were collected to improve the knowledge in the fields related to the project topic, as well as to solve the lack of information in certain points of the project. On the other hand, simulation model programming requires quantitative data. Once the model was completed, simulation results were obtained through simulation-based optimization. This optimization process tested 50,000 different workforce scenarios to find the most efficient solutions for three different sequences. Among all results, the most interesting one for Volvo is the one which render 80% of today’s throughput with the minimum number of workers. Consequently, as a case study, a bottleneck analysis and worker performance analysis was performed for this scenario.

    Finally, a flexible and fully functional model that delivers the desired results was developed. These results provide a comparison among different manning scenarios considering throughput as main measurement of the main final assembly line performance. After analyzing the results, system output behavior was revealed. This behavior allows predicting optimal system output for a given number of operators. 

  • 384.
    López Fernández, Antonio José
    et al.
    University of Skövde, School of Engineering Science. University of Málaga.
    López López, Aída
    University of Skövde, School of Engineering Science. University of Málaga.
    Redesign of windows and doors of a convertible car: Hurtan Grand Albaycín redesign2015Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The objective to this bachelor degree project was to redesign a structure of the doors and add windows of a convertible car. This was carried out in collaboration with the company Hurtan Desarrollos S.L.

    To establish the requirements for the design, initial studies were performed: a literature review, a benchmark of related products and a study of standard car door designs. After this the final requirements were defined and the concept generation design phase was begun. In this phase a number of design methods were applied. The design concepts were systematically evaluated in respect to if, and to what degree, the concepts met the defined demands and needs of the design. The final concepts were completed with the demands of the company to obtain the results.

    In order to define, create and communicate ideas and solutions, the design was modelled in Solidworks software and exported to Creo Parametric 2.0 to create the final renders. Once the overall design was defined, materials and accessories were specified. The final result is presented in detail in photorealistic renderings and a physical design made by Hurtan Desarrollos S.L.

  • 385.
    Madeleine, Thour
    University of Skövde, School of Engineering Science.
    BOTTLENECK ANALYSIS AND THROUGHPUT IMPROVEMENT THROUGH SIMULATION-BASED MULTI OBJECTIVE OPTIMIZATION2015Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Every production system has its constraints. Ever since Goldratt presented the theory of constraints in the mid 80’s a lot of effort has been made to find the best methods for constraint identification and ways to minimize the constraints in order to gain higher capacity in production. A novel method presented is Simulation-based COnstraint Removal (SCORE). The SCORE method has been proved to be more effective and detailed in the identification and sorting of the constraints when compared with other bottleneck detection methods (Pehrsson 2013). The work in this bachelor’s project has been focused on applying the method to a complex production system in order to further explore the SCORE method’s ability to identify bottlenecks and reveal opportunities to increase the throughput of a production system.

    NorthStar Battery Company (NSB) wishes to perform a bottleneck analysis and optimization in order to find improvements to increase the throughput with 10%. By using the SCORE method, improvement options with a potential to meet the goals of NSB was identified. It also facilitated for the author to further exploit the possibilities of simulation-based optimization and knowledge extraction through the SCORE method.

    By building a valid discrete event simulation model of the production line and use it for optimization, followed by a knowledge extraction, it was possible to identify the top three constraints and the level of improvement needed in the constraining operations. The identified improvements could potentially increase the throughput of the production line by 10-15 percent.

    The project was delimited to exclude the finishing part of the production line and only one battery variant has been included. Through continued work and analysis of the line using the SCORE method it will most likely be possible to even further increase the throughput of the production system and to provide NSB with more knowledge and opportunities to enhance their production effectiveness.

  • 386.
    Magnusson, Lisa
    University of Skövde, School of Engineering Science.
    DESIGN IMPROVEMENTS OF DISTRIBUTION TRANSFORMERS: How to improve conditions of transportation in Vietnam2014Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Nowadays international companies wish to relocate their production to developing countries in Asia. The product design is often developed in Europe and is, therefore, not always adapted to the production (transport and manufacture conditions) present in the country of manufacture. The consequence is less qualitative products e.g. distribution transformers of ABB Vietnam get damaged during transport; a problem none existing in Europe. The purpose of the project was to develop the design of distribution transformers for ABB Vietnam, so they better withstand the transport conditions. This Bachelor Degree Project in Integrated Product Development follow a general design process typically for product development and is divided into four main phases. The four faces are; Exploration (of the ill-defined problem space), Generation (of concepts), Evaluation (of the design proposals), and Communication (of the final design solution). Methodologies as literature studies and empirical investigations (observations and interviews) performed at the ABB Vietnam factory in Hanoi provided information about the problem space and a brief overview of the production of ABB transformers. In the study it emerged that the underlying problem was due to both the structure of the product and the infrastructure of the country, e.g. extreme road conditions, lower standard of transportation means etc. Design methodologies were implemented to systematically create ideas, generate and evaluate a number of concepts. The final design concept chosen was simulated to behaviour adequately of transport in real life to verify that the concept manage its purpose. The concept can be further improved and optimised. The outcome of the study revealed the possibilities of improvement, designers can contribute to increased quality of products by understanding the country of manufacture. The thesis is intended to enlighten people working with product development what they shall consider when designing for transportation, and may be used as a practical example of similar problems. The final design concept is an external support frame attached to the transformer to enhance support and contribute to improved quality – especially under extreme road conditions.

  • 387.
    Mahdavian, Nafise
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Development and Evaluation of Digital Ergonomics Tools to Assess Human Work in Real and Virtual Environments: Based on case studies of manual assembly in Swedish automotive companies2018Report (Other academic)
    Abstract [en]

    ‘Digital ergonomics tools’ is a term used in this research proposal to refer to tools that are used to assess human work in real and virtual environments, where ‘digital’ refers to the use of technology such as computers, sensors, simulation, and data processing, to achieve desired functionality and usability. Digital ergonomics tools are considered as part of the ‘digital factory’. In essence the digital factory is an advanced computer model that either represents a non-yet existing factory, or an existing factory. When the factory is realised, there is an information flow between the real and the digital factory. The digital factory can be used to be informed about status of running production, and to support product and manufacturing development activities to test different design scenarios in the digital model before realising the selected solutions in the real factory. Hence, the digital factory approach assists designers, engineers, ergonomists, and managers to get a better understanding of the current status of the factory, and offers a digital model for testing and deciding upon different design alternatives. In an ergonomics context, such status checks can be related to assessing current ergonomics loads of the work force, or related to ensuring appropriate ergonomics when workstations are introduced or modified due to new product type introductions. However, there is a need to develop and evaluate digital ergonomics tools that has the desired functionality and usability to be integrated in to the digital factory concept. This proposed research addresses those needs.

    The research contributes to advance knowledge about technology and methods for the assessment of human work in real and virtual environments. The research will be carried out in association with development and evaluation research projects in the area of digital ergonomics tools, such as digital human modelling (DHM) tools and smart workwear. Simulation and experiment based strategies will be used to gather data and extract new knowledge. The studies will be carried out both in simulation and laboratory environments at the University, as well as in case studies in manual assembly in Swedish automotive companies.

  • 388.
    Mahdavian, Nafise
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Lind, Carl Mikael
    Unit of Occupational medicine, Karolinska Institutet, Stockholm, Sweden / Division of Ergonomics, KTH Royal Institute of Technology, Huddinge, Sweden.
    Diaz Olivares, Jose Antonio
    Division of Ergonomics, KTH Royal Institute of Technology, Huddinge, Sweden.
    Iriondo Pascual, Aitor
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Brolin, Erik
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Yang, Liyun
    Unit of Occupational medicine, Karolinska Institutet, Stockholm, Sweden / Division of Ergonomics, KTH Royal Institute of Technology, Huddinge, Sweden.
    Forsman, Mikael
    Unit of Occupational medicine, Karolinska Institutet, Stockholm, Sweden / Division of Ergonomics, KTH Royal Institute of Technology, Huddinge, Sweden.
    Hanson, Lars
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Scania CV, Södertälje, Sweden.
    Effect of Giving Feedback on Postural Working Techniques2018In: Advances in Manufacturing Technology XXXII: Proceedings of the 16th International Conference on Manufacturing Research, incorporating the 33rd National Conference on Manufacturing Research, September 11–13, 2018, University of Skövde, Sweden / [ed] Peter Thorvald, Keith Case, Amsterdam, Netherlands: IOS Press, 2018, p. 247-252Conference paper (Refereed)
    Abstract [en]

    Working postures and movements affect work efficiency and musculoskeletal health. To reduce the biomechanical exposure in physically demanding settings, working techniques may be improved by giving instant ergonomic feedback to the operator. This study investigates if feedback can be used to decrease adverse postures and movements in assembly work. A prototype solution of a smart textile workwear was used on a trainee assembly line. Posture and movement signals of 24 trainee operators were sampled via the workwear, transferred to a tablet for analyses and used to provide feedback suggesting improvements of work technique. Two modes of feedback were tested. Every participant’s work technique was measured before and after receiving the feedback and the results were compared. For upper arm elevation angle ≥60, behaviour change is indicated, supporting a positive work technique change, and indicated a future usefulness of technical automatic feedback for operators.

  • 389.
    Mahdavian, Nafise
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ruiz Castro, Pamela
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Brolin, Erik
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Hanson, Lars
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Industrial Development, Scania, Södertälje, Sweden.
    Digital human modelling in a virtual environment of CAD parts and a point cloud2017In: Proceedings of the 5th International Digital Human Modeling Symposium / [ed] Sascha Wischniewski & Thomas Alexander, Federal Institute for Occupational Safety and Health , 2017, p. 283-291Conference paper (Refereed)
    Abstract [en]

    Manual assembly is a time and cost consuming phase of production. It is crucial to design the assembly process so that overall system efficiency, quality output and human well-being meet desired levels. Since manual assembly involve humans, one support in the production design process is to use digital human modelling (DHM) tools to model and assess different design scenarios prior to the actual production process. In the traditional way, various CAD tools are used by engineers to model the production layout and the workstations. Then, these models typically are imported into a DHM tool to simulate human work, and to apply ergonomic evaluation methods on the simulated work tasks. This work, supported by CAD and DHM, can be a time consuming and iterative process as precise information and measurements of the actual assembly environment are needed, e.g. related to actual geometries of factory premises or of facilities surrounding the workstations. However, introducing point cloud scanning technology can provide the user with a more correct and realistic virtual representation of the environment, which allows for a faster and more precise design process.The aim of this paper is to present the developments and capabilities of the DHM tool IPS IMMA (Intelligently Moving Manikins) in an assembly process and in a virtual environment provided by point cloud scanning.

  • 390.
    Mao, Junjie
    et al.
    School of Software, Shanghai Jiao Tong University, Shanghai, China.
    Cai, Hongming
    School of Software, Shanghai Jiao Tong University, Shanghai, China.
    Wang, Wei
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Huang, Chengxi
    School of Software, Shanghai Jiao Tong University, Shanghai, China.
    Chen, Fengming
    Department of Information, Shanghai Waigaoqiao Shipbuilding Co, Ltd Shanghai, China.
    Xu, Boyi
    School of Economics & Management, Shanghai Jiao Tong University Shanghai, China.
    A Web of Things Based Device-adaptive Service Composition Framework2016In: 2016 IEEE 13th International Conference on e-Business Engineering (ICEBE), IEEE, 2016, p. 40-47Conference paper (Refereed)
    Abstract [en]

    In WoT environment, smart things provide RESTful services to expose their resources and operations. There are a large number of smart things that offer the same functionalities but have different service interfaces. Because of the high coupling between device service instances and process specifications like BPEL, the cost of reusing a BPEL specification between different device environments could be extremely high. We propose a device-adaptive service composition framework for WoT environment, in order to help users to apply the business process and service composition technologies more conveniently. In the framework, we design an activity description model, which is a semantic description for business activities, to overcome the shortcoming of directly binding the process and the service. Then, a matching mechanism between the model and the WADL of device services is proposed to select candidate services for the composition. Furthermore, we represent the matching result in a logical composition model, with which the source code of a general service can be automatically generated. The general service is a unified encapsulation for device services that match the functionalities of business activity. So user can interact with the general service instead of the origin services on the device, which decouples the process specification and the actual device services. A case study is offered to illustrate how to apply our framework in an intelligent charging pile sharing platform.

  • 391.
    Marcus, Hesselgren
    et al.
    University of Skövde, School of Engineering Science.
    Vestberg, Victor
    University of Skövde, School of Engineering Science.
    Reducering av ställtider: Verktygshantering2018Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This final year project has been carried out at a legomanufacturing company and they work, among other things, with cutting-edge processing which this work has focused on. The production type at the company is usually called HVLV production. This means that the products they produce are often made for the first time and that the recurring work are few. Which results in long lead-times.

    The purpose of this final year project was to identify which activities that the operators spent the most time on and then select a focus area. Furthermore, map the selected focus area "setup", with time studies and spaghetti charts to define more specific goals. Reduce the number of tool-related activities that occur in a setup by 50%, reduce movements between machine and setup-location by 75% and reduce the search of tools during a setup by 50%. This were the goals that lay as a foundation for the final year project. To achieve these goals, some suggested improvements were made. A number of tools that always will be used in the machines, so-called standardtools were selected and implemented. Related tool lists with relevant information about the tools and their design have also been created in order to facilitate the operators work. The tools were selected with flexibility in focus to fit the HVLV production. This were made through comparing purchase price, the most purchased tools from their largest tool supplier, processing times and the operators own experience. Based on the standard tools a routine was made which the operators should follow, from programming until the operator is ready to start the machine.

    A review of previous work was made to see in what extent the selected standardtools could be used. This showed that 40% of the previously reviewed work could have been manufactured using only the selected standardtools. Furthermore, a theoretical comparison with previous mapping showed that with the standardtools and routine, the number of tool-related activities could be reduced by approximately 40%. This mostly due to the elimination of uncertainties regarding which tools and toolholders that were located in the machines. This also eliminated the search of tools where the target was 50% reduction. According to the mapping of the setups the operator made more transportations to the machine than the number of tools that were to be set. If the operators follow the routine and use the tool carrier, only one transportation to the machine is required after all the tools are set. This results in a great reduction of movements to and from the machine. The result shows that about 90% of the movements in one of the mapped setups had been reduced.

  • 392.
    Maric, Toni
    et al.
    University of Skövde, School of Engineering Science.
    Evervall, Ida
    University of Skövde, School of Engineering Science.
    Utveckling av dörrtillbehör för att få in ljus i hall2014Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    During spring 2014, Ida Evervall and Toni Maric from the University of Skövde have carried out a project with a door making company. Daylight admission into to hallways in apartments is basically non-existent today and lamps are used to satisfy the need of light. A door accessory has been developed in order to collect light from the outside of the apartment and transport it through the door to the inside, with no transparency. The client wanted that the transport of light would mainly be done with fiber optics. Experiments showed that fiber optics were sufficient to transport the light, a collecting lens in front gave significantly better result in sunny days. Cloudy days, it was considered enough to mark the position of the door. A market research confirmed that dark hallways was a fact and that transparency-protected door accessories was highlighted together with requirements for price and other safety requirements such as fire, sound, burglary etc.

    Several solutions to the sub-functions of the door accessory were generated, combined and developed. Evaluations were carried out in the form of tests and in discussion with the client. Then one concept was elected and named BeeLight. BeeLight consists of a pentagon-shaped lens surrounded by five hexagonal lenses that focus the light into the fiber optic bundle. The collecting lens is a solution that collects light from different directions as the sun moves throughout the day. A simple test showed that BeeLight provides about 10 lumen on a sunny day. More tests should be conducted in order to obtain exact numbers on how much light BeeLight can transport into the hallway.

  • 393.
    Martin Villaescusa, Laura
    et al.
    University of Skövde, School of Engineering Science.
    Benavides Montes, Maria del Mar
    University of Skövde, School of Engineering Science.
    Design proposal of a double base for child restraint system for two children2015Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    In this project the design of a double base for two child restraint seats (CRS) has been developed. The objective of this project is to facilitate the transportation of two children in the rear seats of a car, maximizing the space available in the rear of the car and providing a comfortable movement to the user when placing the CRS baskets into the car. Scientific articles have been analysed providing a reference of the strength limitations and ergonomics aspects of the users as well as misuse of current CRS. Also, ergonomics and safety issues have been studied through these articles in order to fulfil with the current regulations established by the EU standards and the regulation 44 of Economic Commission for Europe. A market research and survey investigations have been done in order to study the features of existing CRS designs, opinion and needs of habitual users. The employed methodology based on a divergent and convergent design process has been carried out through different methods such as Brainstorming, 6-3-5 Method and Dark Horse Prototype in which many ideas, concepts and proposals have been developed and explained. The results of this project are shown and explained through a virtual 3D CAD model with their respective renders, explanations and technical drawings. The use and material selection of the final design are presented as well as the results of an ergonomic study performed by test with a simple physical prototype of the final design. The main outcomes of this project are included in conclusion, discussions and future work sections.

  • 394.
    Martínez Conde, Sergio
    et al.
    University of Skövde, School of Engineering Science.
    Pérez Luque, Estela
    University of Skövde, School of Engineering Science.
    Exoskeleton for hand rehabilitation2018Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This document presents the development of a first proposal prototype of a rehabilitation exoskeleton hand. The idea was to create a lighter, less complex and cheaper exoskeleton than the existing models in the market but efficient enough to carry out rehabilitation therapies.The methodology implemented consists of an initial literature review followed by data collection resulting in a pre-design in two dimensions using two different software packages, MUMSA and WinmecC. First, MUMSA provides the parameters data of the movement of the hand to be done accurately. With these parameters, the mechanisms of each finger are designed using WinmecC. Once the errors were solved and the mechanism was achieved, the 3D model was designed.The final result is presented in two printed 3D models with different materials. The models perform a great accurate level on the motion replica of the fingers by using rotary servos. The properties of the model can change depending on the used material. ABS material gives a flexible prototype, and PLA material does not achieve it. The use of distinct methods to print has a high importance on the difficulties of development throughout the entire process of production. Despite found difficulties in the production, the model was printed successfully, obtaining a compact, strong, lightweight and eco-friendly with the environment prototype.

  • 395.
    Marzi, Stephan
    et al.
    Fraunhofer IFAM, Bremen, Germany.
    Biel, Anders
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Hesebeck, Olaf
    Fraunhofer IFAM, Bremen, Germany.
    3D optical displacement measurements on dynamically loaded adhesively bonded T-peel specimens2015In: International Journal of Adhesion and Adhesives, ISSN 0143-7496, E-ISSN 1879-0127, Vol. 56, p. 41-45Article in journal (Refereed)
    Abstract [en]

    Adhesively bonded T-Peel specimens are loaded in a rotary impact device to investigate the behaviour of adhesive joints under high-strain rates. To gain a better understanding of that kind of tests and their results, the deformation of the samples as well as the movement of specimen support during the test is analyzed. A three-dimensional optical measurement system is used in combination with two synchronized high-speed cameras to obtain the deformations. The paper explains the experimental challenges and discusses the results of the analyses with respect to a planned usage of the experimental results in a finite element crash simulation. As main results of the investigations it can be summarized that the compliant clamping leads to an inadvertent out-of-plane-movement of the load introduction point. Based on finite element calculations it can be concluded that the measured out-of-plane-movement possesses a negligible influence on the obtained force signal, which is of primary interest in a T-Peel test.

  • 396.
    Marzi, Stephan
    et al.
    Fraunhofer IFAM, Bremen, Germany.
    Hesebeck, Olaf
    Fraunhofer IFAM, Bremen, Germany.
    Brede, Markus
    Fraunhofer IFAM, Bremen, Germany.
    Nagel, Christof
    Fraunhofer IFAM, Bremen, Germany.
    Biel, Anders
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Walander, Tomas
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Stigh, Ulf
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Effects of the bond line thickness on the fracture mechanical behaviour of structural adhesive joints2014In: Proceedings of the Annual Meeting of the Adhesion Society 2014, Adhesion Society , 2014, p. 189-192Conference paper (Refereed)
  • 397.
    Marzi, Stephan
    et al.
    Fraunhofer IFAM, Germany.
    Walander, Tomas
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Hesebeck, Olaf
    Fraunhofer IFAM, Germany.
    Brede, Markus
    Fraunhofer IFAM, Germany.
    A Controlled Mixed-Mode Bending (CMMB) test to investigate the fracture of structural adhesive joints2014Conference paper (Refereed)
    Abstract [en]

    A so called Controlled Mixed-Mode Bending (CMMB) test is presented, which has been developed toinvestigate the fracture of crash-optimized, elastic-plastic adhesives loaded in mixed-mode. While mostcommon mixed-mode tests, like e.g. the MMB test, work fine with brittle adhesives, the controlled MMBtakes into account the large crack opening displacements at the crack tip and ensures a constant mode mixat the crack tip by the regulation of two actuators. Consequently, the definition of mode mixity is asignificant difference to state-of-the-art experiments, which define the mode mixity in terms of the ratio ofdissipated energy in the single modes and which are therefore based on analytical models or assumptionsconcerning the energy dissipation during the test. A further target of the presented CMMB test is to obtain information on the complete shape of the socalled traction separation law, which describes the relation between stress and displacement inside theadhesive layer. Such traction separation law is often used to define the failure behaviour of an adhesivejoint within a numerical analysis, using cohesive elements in a finite element code or similar approaches. Beside the theory and the idea of the CMMB test, experimental results for the adhesive SikaPower 498 arepresented and deeply discussed with respect to difficulties and limitations of the proposed method and therealized experimental setup.

  • 398.
    Mattsson, Sandra
    et al.
    Chalmers University of Technology.
    Fast-Berglund, Åsa
    Chalmers University of Technology.
    Li, Dan
    Chalmers University of Technology.
    Thorvald, Peter
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Forming a cognitive automation strategy for Operator 4.0 in complex assembly2020In: Computers & industrial engineering, ISSN 0360-8352, E-ISSN 1879-0550, Vol. 139, article id 105360Article in journal (Refereed)
    Abstract [en]

    Due to today’s technological advances in the area of Industry 4.0, having a strategy for cognitive automation solutions is crucial. Operator 4.0, will have handle and manage different work tasks ranging from learning new tasks to solving difficult problems and initiate changes. To support the operator moving between these tasks a strategy for the design of cognitive automation solutions is needed. The suggested strategy has three steps: 1) select assembly phases, 2) choose level of cognitive automation carrier and 3) suggest cognitive automation content. It is important that the operator is part of the design and that the solution supports movement between the phases learning, operational and disruptive phases. The strategy could support manufacturing companies meeting challenges regarding social sustainability e.g. stress, attractive workplaces and demography changes as well as system transparency and complexity.

  • 399.
    Mattsson, Sandra
    et al.
    Chalmers University of Technology, Gothenburg, Sweden.
    Fast-Berglund, Åsa
    Chalmers University of Technology, Gothenburg, Sweden.
    Thorvald, Peter
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    A Relationship Between Operator Performance and Arousal in Assembly2016In: Procedia CIRP, ISSN 2212-8271, E-ISSN 2212-8271, Vol. 44, p. 32-37Article in journal (Refereed)
    Abstract [en]

    In order to meet the challenges of future complex systems, manufacturing companies need to better understand how social sustainability affects the operator. One way of studying this is to investigate the possible relationships between operator performance and emotion in an assembly experiment. 60 participants took part in an experiment to investigate the relationships between operator performance and objective and subjective arousal. Results showed a weak relationship between operator performance and objective arousal but no significant relationship was found between performance and subjective arousal. The relationships indicate that further studies on operator emotion could be important to better assembly performance. A tool for doing this might be the Qsensor used in this experiment (measure of objective arousal). More studies are needed to further investigate found relationship and if objective emotion measures can be used to predict performance at assembly workstations.

  • 400.
    Melle, Daniel
    et al.
    University of Skövde, School of Engineering Science.
    Johan, Larsson
    University of Skövde, School of Engineering Science.
    Mätningar av kantviksmaskin vid klämningsrörelse2019Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In an edge folding machine, used for sheet metal bending, which have undesired deformations in the mechanism that clamps the work material there is a risk that the deformations will cause the work material to be moved and this can affect the position of the bending. The aim of the study was to measure loads and deformations in the edge folding machine and compile measurement data to compare with FEM-analyzes of the design to get a basis for future work with the machine. The problem was investigated by carrying out measurements with LVDT-sensors and a load cell. The results showed that there was a displacement in the clamping of the work material and that the clamping force varied. The FEM-analyzes came up in a lower displacement than the measured one. A possible conjecture could be that a part of the displacement may be due to the tool change mechanism. To confirm this, measurements need to be performed which can show the contribution of deformation from this mechanism. The FEM-analyzes were made with different load distribution to correspond to the clamping force. The analysis with a divided load where the sectioning was based on the distribution of the clamping force that was measured gave a distribution of the displacement that was similar to the measured. For future analyzes it is recommended to use this or a similar load distribution. Based on measurements and analyzes it is found that the upper prism is bent and twisted during the clamping. This changes the position of the top tools and contribute to no clamping in the middle positions.

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