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  • 51.
    Andreasson, Rebecca
    et al.
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    Lindblom, Jessica
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    Thorvald, Peter
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Towards an increased degree of usability work in organizations2015Ingår i: Procedia Manufacturing, ISSN 2351-9789, Vol. 3, s. 5739-5746Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    It is widely recognized that there is a substantial gap between usability research and practice where UCD approaches are rarelyapplied in practice due to arguments regarding the intricate nature of its methods and techniques. This paper presents an actionresearch study designed to investigate and analyze the potentials for an increased degree of UCD activities in the earlydevelopment phases of advanced information systems technology. The results demonstrate that there is a large interest inusability but that organizational priority and competence is often lacking. Instead one relies heavily on questionable conceptssuch as „trained professionals‟ to excuse the low effort towards usability. Based on the results, six recommendations forimproved usability work in R&D organizations are presented, focusing on the importance of prioritization of, and education inusability work.

  • 52.
    Antonsson, Arvid
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Hermansson, Gustaf
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    System analysis, improvement and visualisation of a manufacturing workflow, using discrete-event simulation: A combination of discrete-event simulation and lean manufacturing2019Självständigt arbete på grundnivå (kandidatexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This project has been initiated in cooperation with a Swedish manufacturing company. Due to increased demand and competition, the company wants to streamline its production process, increase the degree of automation and visualize specific workflows. By creating a frame of reference and a literature review, a theoretical basis for methods and concepts which has been utilized throughout the project has been obtained. With the help of the identified methods and methodologies, a current state analysis was performed. Using traditional Lean tools such as Genchi genbutsu, Ishikawa diagram and a 5-why analysis, in combination with time studies and interviews, the current state of the studied system was successfully mapped and analysed. With the help of the current state analysis, which served as a conceptual model, a simulation model of the current state was created in order to handle the large variety and the complexity of the system. The simulation model was validated and verified in order to ensure that it was “good enough” for the purpose of this project in the depiction of the real world system. During the experimental design, several improvement suggestions were created by utilizing methods such as brainstorming, Ishikawa diagram and a 5-why analysis. In a Kaizen event, onsite personnel had the opportunity to decide which suggestions that was fit for experimentation using simulation. With the result of the Kaizen event, experiments were performed in order to evaluate the proposed improvement suggestion. As a result, several new insights regarding improvements could be obtained, which provided several suggestions for an improved future state. Including a proposed automated cell. The analysis of the results did not entirely satisfy the aim of the project since certain factors could not be analysed, therefore the authors recommend that further studies are needed if proposed improvement suggestions are to be implemented.

  • 53.
    Apelgren, Tommy
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Gottschlich, Marcus
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Automation och Simulering på S:t Eriks2019Självständigt arbete på grundnivå (högskoleexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
  • 54.
    Aragón Martín, Laura
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Alternative materials for the horseshoe2014Självständigt arbete på grundnivå (kandidatexamen), 15 poäng / 22,5 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This thesis is a research-focused work on a study of alternative materials for horseshoes. Within this thesis the objectives and functions of a compliant horseshoe are identified, based on a literature study of the work of previous researches, and they are linked to the properties of material. After identifying these objectives, a number of methods are implemented with the aim of detecting the most suitable materials for horseshoes taking into account the properties linked with the objectives. In order to determine whether the selected material is suitable or not, a comparison with a traditional forged steel horseshoe is carried out. Whenever an appropriate material is found, a most exhaustive study is performed and finally, a decision is elected based on the further investigation. The last chapter of this thesis is comprised of a document destined for future researches where suggestions about how to get more reliable results in the field are explained.

  • 55.
    Arambarri Iglesias, Oihane
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Arauzo Sanchez, Ane
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Design of a medical mask for users with Multiple Chemical Sensitivity2016Självständigt arbete på grundnivå (kandidatexamen), 15 poäng / 22,5 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Within this degree project a conceptual design of a mask has been developed for people with Multiple Chemical Sensitivity due to the lack of this kind of product in the market. The users currently use different masks that are designed to be used in other activities.  A preliminary study has been performed where market, ergonomics, materials and use situations have been analysed to gather knowledge to define the specifications of the product. Even if  the aesthetics of the first version of the product’s design was related to a health care design style, after obtaining results, it was observed that the wishes of the users weren’t being fulfilled. After updating the specifications and the generation phase three possible concepts have been presented. The evaluation has been done within the design group and the target users from the Basque association “Bizi-Bide”. The final conceptual design has been developed regarding different aspects such as ergonomics, materials, components and graphic design. The project has resulted in a concept of an innovative mask, which has a mouldable part for the nose and cheeks, a Velcro fastener to adapt it to different head measurements and exchangeable filters. 

  • 56.
    Arehorn, Magnus
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Ekholm, Niklas
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Utveckling av lattbeslag för segelbåtar mellan 45 och 60 fot2016Självständigt arbete på grundnivå (kandidatexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Projektet har utförts av designingenjörsstudenterna Magnus Arehorn och Niklas Ekholm under vårterminen 2016 i kursen Examensarbete inom integrerad produktutveckling på Högskolan i Skövde. Projektet har genomförts för Seldén Mast AB i Långedrag, Göteborg, som utvecklar däcks- och riggsutrustning för segelbåtar.Seldén har lattbeslag för segelbåtar upp till 45 fot, men vill utöka sitt sortiment till marknad för större segelbåtar. De befintliga lattbeslagen skulle då inte vara tillräckligt robusta varför ett nytt beslag krävs med starkare konstruktion. Målet var att utveckla ett lattbeslag för segelbåtar mellan 45 och 60 fot. Syftet med lattbeslaget är att spänna upp lattor i storseglet och utfå bättre vindupptagning.Utvecklingsområden undersöktes genom att delfunktioner för beslaget identifierades. En förstudie inleddes för att forska i utvecklingsmöjligheter inom områdena genom att se till befintliga lösningar via konkurrensanalys och behov i intervjuer med segelmakare och seglare. Beslaget förväntades vara billigt, robust, funktionellt samt unikt. Slutsatsen drogs att unika lösningar behövde finnas till en låg tillverkningskostnad.En idégenerering inleddes för att finna koncept med nytänkande och beprövade lösningar till låga kostnader. Två potentiella koncept togs fram som efter detaljutveckling viktades för att stå med ett slutligt resultat. Resultatet bedömdes vara ovanligt på marknaden och uppskattades ha en relativt låg tillverkningskostnad.

  • 57.
    Areitioaurtena Oiartzun, Maialen
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Mixed material bonding: Effects of the properties of the adhesive on the thermal shape distortion2016Självständigt arbete på grundnivå (kandidatexamen), 15 poäng / 22,5 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Adhesive bond-line read-through is the terminology used in the automotive industry that describes a visible distortion of an adherent over the adhesive bond-line. Usually, this is a result of the difference in the coefficients of thermal expansion of the substrates and the adhesive. First of all, previous work is presented, as well as some information about the terms that are used throughout the project. A linear thermal simulation is carried out in order to analyse the bond-line read-through curvature defects produced by the adhesive properties in a typical bonding from the automotive industry. The analysed models belong to a carbon fibre and epoxy composite material plate bonded with a metal plate that can be made of steel, aluminium and magnesium. The use of carbon fibre composites is one of the main focuses in the automotive industry due to the decrease of environmental and therefore economic impact. The adhesives used for the analysis are liquid or paste adhesive and adhesive tapes from the 3M™ VHB™ series. Several equations are obtained from the results, which can be used to calculate the curvature produced by a specific adhesive for these combinations. The use of these equations is limited to certain material properties and thicknesses that are presented through the work. The outcome of this project provides an opportunity to make the adhesive selection easier, based on the maximum required substrate curvature.

  • 58.
    Arteaga Viafara, Edinson Elan
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Linders, Linders
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Utveckling av en postlåda för montage på säkerhetsdörrar2016Självständigt arbete på grundnivå (kandidatexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Denna uppsats går igenom skapandet av ett konstruktionsförslag av en postlåda för montage på säkerhetsdörrar. Projektet genomfördes i samarbete med ett företag som tillverkar säkerhetsdörrar i stål. Syftet med arbetet har varit att på uppdrag av företaget utarbeta ett designförslag för en postlåda med ett flertal nya funktioner samt med en innovativ estetisk formgivning. Designen får inte kompromissa med gällande säkerhetskrav samt bör inkludera en bredare målgrupp.

    Enligt Frenchs modell har en metod använts där användarstudier, tester och fokusgrupper gett viktig information. Designprinciperna inclusive design, pleasure design och gamification har varit ledstjärnor i designprocessen.

    En funktionsanalys gjordes på en vanlig postlåda som visade vilka funktioner som kan förbättras. Denna analys utgjorde grunden för den efterföljande konceptgenereringsfasen där olika designalternativ utforskades.

    Konceptgenereringen utmynnade i postlådan Droppen, där redan existerande funktioner har vidareutvecklats. Droppen-konceptet utmanar genom att exempelvis introducera LED-lampor som kommunicerar med användaren samt har ett tidningsställ, som är starkt nog att kunna bära tunga matkassar. Den har också en mjuk droppform som tilltalar många och som gör det lätt att ta upp posten. Postlådan är gjord i zinklegerat stål, vilket gör den tung men hållbar. Möjligheten till individuell anpassning av produkten ökar kundvärdet samt minskar indirekt dess miljöpåverkan

  • 59.
    Arufors, Robert
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Reducerad tidsvariation vid monteringsmoment2019Självständigt arbete på grundnivå (högskoleexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
  • 60.
    Aryasetiawan, F.
    et al.
    Department of Physics, Division of Mathematical Physics, Lund University, Lund, Sweden.
    Karlsson, Krister
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Miyake, T.
    CD-FMat, AIST, Tsukuba, Japan / ESICMM, National Institute for Materials Science, Tsukuba, Japan.
    Green's function theory of orbital magnetic moment of interacting electrons in solids2016Ingår i: Physical Review B Condensed Matter, ISSN 0163-1829, E-ISSN 1095-3795, Vol. 93, nr 16, artikel-id 161104(R)Artikel i tidskrift (Refereegranskat)
  • 61.
    Aryasetiawan, Ferdi
    et al.
    Department of Physics, Division of Mathematical Physics, Lund University, Lund, Sweden.
    Karlsson, Krister
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Modern theory of orbital magnetic moment in solids2019Ingår i: Journal of Physics and Chemistry of Solids, ISSN 0022-3697, E-ISSN 1879-2553, Vol. 128, s. 87-108Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The magnetic moment in a solid is usually associated with the electron spins but there is an additional contribution due to the orbital motion of the electrons. For a finite system such as an atom or molecule the orbital moment can be readily calculated. However, for a periodic system the formula used for finite systems becomes ill-defined due to the presence of the position operator. In the last decade a modern theory of orbital magnetization that allows for a rigorous calculation of the magnetic moment of periodic crystals has been developed. This article provides a survey of the theoretical development of this new topic as well as recent, albeit a few, applications of the new formula to real materials. Although the original theory was worked out for non-interacting systems, there has been recent progress in the theory of orbital magnetic moment of interacting electrons in solids. To include the effects of electron-electron interactions two approaches have been proposed, one based on current spin density functional theory and another on the many-body Green's function method. The two approaches are very different but both methods provide convenient yet rigorous means of including the effects of exchange and correlations beyond the commonly used local density approximation of density functional theory.

  • 62.
    Aslam, Tehseen
    et al.
    Högskolan i Skövde, Forskningscentrum för Virtuella system. Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Ng, Amos H. C.
    Högskolan i Skövde, Forskningscentrum för Virtuella system. Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Combining system dynamics and multi-objective optimization with design space reduction2016Ingår i: Industrial management + data systems, ISSN 0263-5577, E-ISSN 1758-5783, Vol. 116, nr 2, s. 291-321Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose 

    The purpose of this study is to introduce an effective methodology for obtaining Pareto-optimal solutions, when combining System Dynamics (SD) and Multi-Objective Optimization (MOO) for supply chain problems.

    Design/methodology/approach 

    This paper proposes a new approach that combines SD and MOO within a simulation-based optimization framework to generate the efficient frontier that supports decision- making in SupplyChain Management (SCM). It also addresses the issue of the curse of dimensionality, commonly found in practical optimization problems, through design space reduction.

    Findings 

    The integrated MOO and SD approach has been shown to be very useful in revealing how the decision variables in the Beer Game affect the optimality of the three common SCM objectives, namely, the minimization of inventory, backlog, and the bullwhip effect. The results of the in-depth Beer Game study clearly show that these three optimization objectives are in conflict with each other, in the sense that a supply chain manager cannot minimize the bullwhip effect without increasing the total inventory and total backlog levels.

    Practical implications

    Having a methodology that enables the effective generation of optimal trade-off solutions, in terms of computational cost, time, as well as solution diversity and intensification, not only assists decision makers to make decisions on time, but also presents a diverse and intense solution set to choose from.

    Originality/value 

    This paper presents a novel supply chain MOO methodology that helps to find Pareto-optimal solutions in a more effective manner. In order to do so, the methodology tackles the so-called curse of dimensionality, by reducing the design space and focusing the search of the optimization to regions of interest. Together with design space reduction, it is believed that the integrated SD and MOOapproach can provide an innovative and efficient method for the design and analysis of manufacturing supply chain systems in general.

  • 63.
    Aslam, Tehseen
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Ng, Amos H. C.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Bandaru, Sunith
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Multi-objective Optimization and Analysis of the Inventory Management Model2014Ingår i: Proceedings of the 2014 Summer Simulation Multiconference, Society for Computer Simulation International , 2014, Vol. 46, s. 99-106Konferensbidrag (Refereegranskat)
  • 64.
    Aslam, Tehseen
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Ng, Amos H. C.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Karlsson, Ingemar
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Integrating system dynamics and multi-objective optimisation for manufacturing supply chain analysis2014Ingår i: International Journal of Manufacturing Research, ISSN 1750-0605, Vol. 9, nr 1, s. 27-57Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this paper is to address the dilemma of supply chain management (SCM) within a truly Pareto-based multi-objective context. This is done by introducing an integration of system dynamics and multi-objective optimisation. An extended version of the well-known pedagogical SCMproblem, the Beer Game, originally developed at MIT since the 1960s, has been used as the illustrative example. As will be discussed in the paper, the integrated multi-objective optimisation and system dynamics model has been shown to be very useful for revealing how the parameters in the Beer Game affect the optimality of the three common SCM objectives, namely, the minimisation of inventory cost, backlog cost, and the bullwhip effect.

  • 65.
    Aslam, Tehseen
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Ng, Amos H.C.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Strategy evaluation using system dynamics and multi-objective optimization for an internal supply chain2015Ingår i: Proceedings of the 2015 Winter Simulation Conference / [ed] L. Yilmaz, W. K. V. Chan, I. Moon, T. M. K. Roeder, C. Macal and M. D. Rossetti, Piscataway, NJ, USA: IEEE Press, 2015, s. 2033-2044Konferensbidrag (Refereegranskat)
    Abstract [en]

    System dynamics, which is an approach built on information feedbacks and delays in the model in order to understand the dynamical behavior of a system, has successfully been implemented for supply chain management problems for many years. However, research within in multi-objective optimization of supply chain problems modelled through system dynamics has been scares. Supply chain decision making is much more complex than treating it as a single objective optimization problem due to the fact that supply chains are subjected to the multiple performance measures when optimizing its process. This paper presents an industrial application study utilizing the simulation based optimization framework by combining system dynamics simulation and multi-objective optimization. The industrial study depicts a conceptual system dynamics model for internal logistics system with the aim to evaluate the effects of different material flow control strategies by minimizing total system work-on-process as wells as total delivery delay.

  • 66.
    Aslam, Tehseen
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Syberfeldt, Anna
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Ng, Amos
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Pehrsson, Leif
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system. Volvo Car Engine, Manufacturing Research and Concepts, Skövde, Sweden.
    Urenda-Moris, Mathias
    Uppsala University, Ångströmlaboratoriet, Uppsala, Sweden.
    Towards an industrial testbed for holistic virtual production development2018Ingår i: 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, s. 369-374Konferensbidrag (Refereegranskat)
    Abstract [en]

    Virtual production development is adopted by many companies in the production industry and digital models and virtual tools are utilized for strategic, tactical and operational decisions in almost every stage of the value chain. This paper suggest a testbed concept that aims the production industry to adopt a virtual production development process with integrated tool chains that enables holistic optimizations, all the way from the overall supply chain performance down to individual equipment/devices. The testbed, which is fully virtual, provides a mean for development and testing of integrated digital models and virtual tools, including both technical and methodological aspects.

  • 67.
    Assarsson, Jonas
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Kommunikation av förbättringsarbeten: en studie i medelstora tillverkande företag2015Självständigt arbete på grundnivå (högskoleexamen), 15 poäng / 22,5 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Uppkomsten av detta examensarbete grundas i ett forskningsprojekt på Högskolan i Skövde, vars syfte är att studera hur ledning och mätning av ständiga förbättringar kan förbättras i medelstora tillverkande företag. Syftet med examensarbetet var att ge förutsättningar för företagen att förbättra sin kommunikation av förbättringsarbeten. Arbetet omfattade att kartlägga all formell skriftlig kommunikation av förbättringsarbeten, men inte det som kommuniceras muntligen, i två företag. I Företag A kommunicerades betydligt mer information än i Företag B. I Företag A, som har arbetat länge med Lean Production, observerades kommunikationsformer som målstyrning, daglig styrning och olika kategorier av förbättringsarbeten. I Företag B observerades endast olika kategorier av förbättringsarbeten, detta kan bero på att de är i uppstartsfasen med Lean. Produktionsledarna i Företag A agerar i många av kommunikationsformerna, vilket gör att de får ett stort ansvar i förbättringsarbetet. Företagen i studien men även andra företag bör ta till sig av varandras kommunikationsformer för att nå en effektivare kommunikation av förbättringsarbeten. Företagen bör även rikta medarbetarnas tankar på att minska slöseri samt skapa ett system för att följa upp och mäta avvikelser.

  • 68.
    Auma, Faith
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Lingehed, Emma
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Chair for pupils with cerebral palsy in Uganda2014Självständigt arbete på grundnivå (kandidatexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    En justerbar stol utvecklades för barn med cerebral pares i Uganda. Stolarna dessa barn använder idag är specialdesignade vilket innebär att de inte kan användas när barnet växer ur stolen. Ibland används då stolen av andra barn och ger därmed inte det stöd som barnet behöver.

    Projektet genomfördes i huvudstaden, Kampala, av de två designingenjörsstudenter Faith Auma och Emma Lingehed i samarbete med Makerere University, Kampala school for the physically handicapped och Katalemwa Cheshire home. Målet med projektet var att hjälpa elever med cerebral pares redan från unga år att utveckla ett korrekt sittbeteende och bli mer fysiskt oberoende. Stolen ska kunna tillverkas och monteras i Uganda och materialet ska finnas i landet.

    Projektet började med att studera och klargöra problemet, information samlades in genom litteraturstudier, studiebesök och intervjuer. Den insamlade informationen användes för att skapa en kravspecifikation med fokus på säkerhet, miljö, tillverkning och ergonomi.

    Bakgrundsinformationen användes under idégenereringen. Ett antal idéer genererades och utvärderades tills ett slutgiltigt koncept hittades. Det slutgiltiga konceptet, Billy, valdes genom en concept scoring där det utvärderades mot tre andra koncept. Billy ansågs vara det koncept som var enklast att tillverka i Uganda och hade den enklaste konstruktionen.

    Billy vidareutvecklades och blev det slutliga konceptet Entebbe. Entebbe är en stol som är justerbar och ger det stöd ett barn med cerebral pares behöver. En prototyp tillverkades vid Katalemwa Cheshire home.

    Entebbe kan tillverkas i Uganda och eftersom den är modulbaserad är den lätt att reparera och ändra storlek på genom att enkelt byta ut de berörda delarna. Detta innebär att delarna även kan återanvändas för att bygga andra stolar. Entebbe kan justeras på fem olika sätt och inga verktyg krävs för att montera ihop stolen.

  • 69.
    Axelsson, Jonathan
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Hultberg, Carl
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Realtidsstyrning av robotiserad kameraplattform2018Självständigt arbete på grundnivå (kandidatexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Försvarets materielverk (FMV), som förser Svenska försvaret med materiel, har en del av sin organisation belägen i Karlsborg nämligen test och evaluering av markstridssystem. Fotogruppen på test och evaluering önskar realtidsstyra en robotiserad kameraplattform av märket Vinten med hjälp av diverse olika positionsgivande system i form av joystick, Doppler-positionsradar, deras självutvecklade system UNIPOS samt en predikterad bana för avlossade projektiler. Projektets huvudsakliga mål blev därför att skapa ett styrsystem för att kontrollera kameraplattformen med hjälp av nämnda indatakällor. Den teoretiska referensramen samt litteraturstudien gav projektets deltagare den kunskapsbas, inom seriell kommunikation och dataprotokoll, som krävdes för att genomföra projektet. De gav även förståelse för hur tidigare liknande arbeten sett ut och valde utifrån detta att följa systemutvecklingsmodellen Rational Unified process (RUP). FMV uttryckte önskemål om att den huvudsakliga styrenheten skulle vara en PC för att möjliggöra fjärrstyrning samt enkel vidareutveckling av systemet. RUP användes för att strukturera upp arbetet samt säkerställa kvalitén på slutprodukten. Utvecklingsprocessen består, enligt RUP’s struktur, av ett antal iterationer som alla tillför någon funktion till systemet. I samråd och nära samarbete med personal på FMV utvecklades systemet och testades succesivt för att säkerställa kvalitén. En enkel manual togs även fram för att förenkla användandet av systemet. Samtliga önskade indatakällor behandlades på något sätt i projektet och resultatet blev ett portabelt system som kan köras på vilken PC som helst. Tester med drönare, granatkastare samt ett stegsvar har utförts för att verifiera att systemets funktion uppfyller de krav som satts upp samt utvärdera systemets möjligheter och begränsningar. Testen visade att realtidsstyrning är möjlig till viss grad med samtliga system och att systemets begränsningar ligger i fördröjningarna som finns både i signalöverföring samt kameraplattformens inbyggda filter för mjuka rörelser.

  • 70.
    Ayani, Mikel
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Ganebäck, Maria
    Projektengagemang Industri & Energi Sverige AB, El & Automation, Skövde, Sweden.
    Ng, Amos H. C.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Digital Twin: Applying emulation for machine reconditioning2018Ingår i: Procedia CIRP, ISSN 2212-8271, E-ISSN 2212-8271, Vol. 72, s. 243-248Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Old machine reconditioning projects extend the life length of machines with reduced investments, however they frequently involve complex challenges. Due to the lack of technical documentation and the fact that the machines are running in production, they can require a reverse engineering phase and extremely short commissioning times. Recently, emulation software has become a key tool to create Digital Twins and carry out virtual commissioning of new manufacturing systems, reducing the commissioning time and increasing its final quality. This paper presents an industrial application study in which an emulation model is used to support a reconditioning project and where the benefits gained in the working process are highlighted.

  • 71.
    Ayani, Mikel
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Ng, Amos H. C.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Birtic, Martin
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Optimizing Cycle Time and Energy Efficiency of a Robotic Cell Using an Emulation Model2018Ingår i: 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, Vol. 8, s. 411-416Konferensbidrag (Refereegranskat)
    Abstract [en]

    Industrial automated systems are mostly designed and pre-adjusted to always work at their maximum production rate. This leaves room for important energy consumption reductions considering the production rate variations of factories in reality. This article presents a multi-objective optimization application targeting cycle time and energy consumption of a robotic cell. A novel approach is presented where an existing emulation model of a fictitious robotic cell was extended with low-level electrical components modeled and encapsulated as FMUs. The model, commanded by PLC and Robot Control software, was subjected to a multi-objective optimization algorithm in order to find the Pareto front between energy consumption and production rate. The result of the optimization process allows selecting the most efficient energy consumption for the robotic cell in order to achieve the required cycle.

  • 72.
    Azamfirei, Victor
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    A visualization approach for improved interpretation and evaluation of assembly line balancing solutions2018Självständigt arbete på avancerad nivå (magisterexamen), 15 poäng / 22,5 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Future manufacturing will be characterized by the complementarity between humans and automation (human-robot collaboration). This requires new methods and tools for the design and operation of optimized manufacturing workplaces in terms of ergonomics, safety, efficiency, complexity management and work satisfaction. There have been some efforts in the recent years to propose a tool for determining optimal human-automation levels for load balancing.

    Although the topic is quite new, it shares some similarities with some of the existing research in the area of robotic assembly line balancing. Therefore, it is crucial to review the existing literature and find the most similar models and methods to facilitate the development of new optimization models and algorithms.

    One of the two contributions that this thesis gives to the research world in the RALBP context is a literature review that involves high quality articles from 1993 to beginning 2018. This literature review includes visual and comprehensive tables—and a label system— where previous research patterns and trends are highlighted.

    Visualization of data and results obtained by assembly line optimization tools is a very important topic that has rarely been studied. Data visualization would provide a: 1. better comprehension of patterns, trends and qualitative data 2. more constructive information absorption 3. better visualization of relationships and patterns between operations, and 4. better contribution to data manipulation and interaction.

    The second contribution to research found in this thesis is the use of a human modelling (DHM) tool (called IPS), which is proposed as an assessment to the ergonomic risk that a robotic assembly line may involve. This kind of studies are necessary in order to reduce one of the most frequent reasons of work absence in our today society i.e. musculoskeletal disorders (MSDs). MSDs are often the result of poor work environments and they lead to reduced productivity and quality losses at companies. In view of the above, IPS was used in order to resolve the load handling problem between human and robot, depending on their skills and availability, while fulfilling essential ISO standards i.e. 15066 and 10218:1 and :2. The literature review made it possible to select highly useful documents in developing assumptions for the experiment and contributed to consider real features detected in the industry.

    Results show that even though IPS is not capable of calculating an entire robotic assembly with human-robot collaboration, it is able to simulate a workstation constituted of one robot and one human. Finite and assembly motions for both human and robot are expected to be implemented in future versions of the software.

    Finally, the main advantages of using DHM tools in assessing ergonomic risks in RALB can be extracted from the results of this thesis. This advantages include 1. ergonomic evaluation for assembly motions 2. ergonomic evaluation for a full working day (available in future version) and 3. essential ISO standard testing (available in future version).

  • 73.
    Azamfirei, Victor
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. 1994.
    A visualization approach for improved interpretation and evaluation of assembly line balancing solutions2018Självständigt arbete på avancerad nivå (magisterexamen), 15 poäng / 22,5 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Future manufacturing will be characterized by the complementarity between humans and automation (human-robot collaboration). This requires new methods and tools for the design and operation of optimized manufacturing workplaces in terms of ergonomics, safety, efficiency, complexity management and work satisfaction. There have been some efforts in the recent years to propose a tool for determining optimal human-automation levels for load balancing.

    Although the topic is quite new, it shares some similarities with some of the existing research in the area of robotic assembly line balancing. Therefore, it is crucial to review the existing literature and find the most similar models and methods to facilitate the development of new optimization models and algorithms.

    One of the two contributions that this thesis gives to the research world in the RALBP context is a literature review that involves high quality articles from 1993 to beginning 2018. This literature review includes visual and comprehensive tables—and a label system— where previous research patterns and trends are highlighted.

    Visualization of data and results obtained by assembly line optimization tools is a very important topic that has rarely been studied. Data visualization would provide a: 1. better comprehension of patterns, trends and qualitative data 2. more constructive information absorption 3. better visualization of relationships and patterns between operations, and 4. better contribution to data manipulation and interaction.

    The second contribution to research found in this thesis is the use of a human modelling (DHM) tool (called IPS), which is proposed as an assessment to the ergonomic risk that a robotic assembly line may involve. This kind of studies are necessary in order to reduce one of the most frequent reasons of work absence in our today society i.e. musculoskeletal disorders (MSDs). MSDs are often the result of poor work environments and they lead to reduced productivity and quality losses at companies. In view of the above, IPS was used in order to resolve the load handling problem between human and robot, depending on their skills and availability, while fulfilling essential ISO standards i.e. 15066 and 10218:1 and :2. The literature review made it possible to select highly useful documents in developing assumptions for the experiment and contributed to consider real features detected in the industry.

    Results show that even though IPS is not capable of calculating an entire robotic assembly with human-robot collaboration, it is able to simulate a workstation constituted of one robot and one human. Finite and assembly motions for both human and robot are expected to be implemented in future versions of the software.

    Finally, the main advantages of using DHM tools in assessing ergonomic risks in RALB can be extracted from the results of this thesis. This advantages include 1. ergonomic evaluation for assembly motions 2. ergonomic evaluation for a full working day (available in future version) and 3. essential ISO standard testing (available in future version). 

  • 74.
    Azamfirei, Victor
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Preciado Navarro, Luis Donaldo
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Interface Design for Driver Operated Control Systems2017Självständigt arbete på grundnivå (kandidatexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
  • 75.
    Bandaru, Sunith
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Andersson, Martin
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Ng, Amos H. C.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Metamodel-based prediction of performance metrics for bilevel parameter tuning in MOEAs2016Ingår i: 2016 IEEE Congress on Evolutionary Computation (CEC), New York: IEEE, 2016, s. 1909-1916Konferensbidrag (Refereegranskat)
    Abstract [en]

    We consider a bilevel parameter tuning problem where the goal is to maximize the performance of a given multi-objective evolutionary optimizer on a given problem. The search for optimal algorithmic parameters requires the assessment of several sets of parameters, through multiple optimization runs, in order to mitigate the effect of noise that is inherent to evolutionary algorithms. This task is computationally expensive and therefore, in this paper, we propose to use sampling and metamodeling to approximate the performance of the optimizer as a function of its parameters. While such an approach is not unheard of, the choice of the metamodel to be used still remains unclear. The aim of this paper is to empirically compare 11 different metamodeling techniques with respect to their accuracy and training times in predicting two popular multi-objective performance metrics, namely, the hypervolume and the inverted generational distance. For the experiments in this pilot study, NSGA-II is used as the multi-objective optimizer for solving ZDT problems, 1 through 4.

  • 76.
    Bandaru, Sunith
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Aslam, Tehseen
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Ng, Amos
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Deb, Kalyanmoy
    Department of Electrical and Computer Engineering, Michigan State University, East Lansing, USA.
    Generalized higher-level automated innovization with application to inventory management2015Ingår i: European Journal of Operational Research, ISSN 0377-2217, E-ISSN 1872-6860, Vol. 243, nr 2, s. 480-496Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper generalizes the automated innovization framework using genetic programming in the context of higher-level innovization. Automated innovization is an unsupervised machine learning technique that can automatically extract significant mathematical relationships from Pareto-optimal solution sets. These resulting relationships describe the conditions for Pareto-optimality for the multi-objective problem under consideration and can be used by scientists and practitioners as thumb rules to understand the problem better and to innovate new problem solving techniques; hence the name innovization (innovation through optimization). Higher-level innovization involves performing automated innovization on multiple Pareto-optimal solution sets obtained by varying one or more problem parameters. The automated innovization framework was recently updated using genetic programming. We extend this generalization to perform higher-level automated innovization and demonstrate the methodology on a standard two-bar bi-objective truss design problem. The procedure is then applied to a classic case of inventory management with multi-objective optimization performed at both system and process levels. The applicability of automated innovization to this area should motivate its use in other avenues of operational research.

  • 77.
    Bandaru, Sunith
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Deb, Kalyanmoy
    BEACON Center for the Study of Evolution in Action, Department of Electrical and Computer Engineering, Michigan State University, USA.
    Metaheuristic Techniques2017Ingår i: Decision Sciences: Theory and Practice / [ed] Raghu Nandan Sengupta, Aparna Gupta, Joydeep Dutta, Boca Raton: CRC Press, 2017, s. 693-750Kapitel i bok, del av antologi (Refereegranskat)
  • 78.
    Bandaru, Sunith
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Deb, Kalyanmoy
    Michigan State University, USA.
    Temporal Innovization: Evolution of Design Principles Using Multi-objective Optimization2015Ingår i: Proceedings of the 8th International Conference on Evolutionary Multi-Criterion Optimization (EMO 2015), Springer, 2015, Vol. 9018, s. 79-93Konferensbidrag (Refereegranskat)
    Abstract [en]

    Multi-objective optimization yields multiple solutions each of which is no better or worse than the others when the objectives are conflicting. These solutions lie on the Pareto-optimal front which is a lower-dimensional slice of the objective space. Together, the solutions may possess special properties that make them optimal over other feasible solutions. Innovization is the process of extracting such special properties (or design principles) from a trade-off dataset in the form of mathematical relationships between the variables and objective functions. In this paper, we deal with a closely related concept called temporal innovization. While innovization concerns the design principles obtained from the trade-off front, temporal innovization refers to the evolution of these design principles during the optimization process. Our study indicates that not only do different design principles evolve at different rates, but that they start evolving at different times. We illustrate temporal innovization using several examples.

  • 79.
    Bandaru, Sunith
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Gaur, Abhinav
    Department of Electrical and Computer Engineering, Michigan State University, USA.
    Deb, Kalyanmoy
    Department of Electrical and Computer Engineering, Michigan State University, USA.
    Khare, Vineet
    Amazon Development Centre (India) Pvt. Ltd., Bengaluru, India.
    Chougule, Rahul
    Department of Mechanical Engineering, Walchand College of Engineering, Sangli, India.
    Bandyopadhyay, Pulak
    General Motors R&D Center, Warren, USA.
    Development, analysis and applications of a quantitative methodology for assessing customer satisfaction using evolutionary optimization2015Ingår i: Applied Soft Computing, ISSN 1568-4946, E-ISSN 1872-9681, Vol. 30, s. 265-278Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Consumer-oriented companies are getting increasingly more sensitive about customer's perception of their products, not only to get a feedback on their popularity, but also to improve the quality and service through a better understanding of design issues for further development. However, a consumer's perception is often qualitative and is achieved through third party surveys or the company's recording of after-sale feedback through explicit surveys or warranty based commitments. In this paper, we consider an automobile company's warranty records for different vehicle models and suggest a data mining procedure to assign a customer satisfaction index (CSI) to each vehicle model based on the perceived notion of the level of satisfaction of customers. Based on the developed CSI function, customers are then divided into satisfied and dissatisfied customer groups. The warranty data are then clustered separately for each group and analyzed to find possible causes (field failures) and their relative effects on customer's satisfaction (or dissatisfaction) for a vehicle model. Finally, speculative introspection has been made to identify the amount of improvement in CSI that can be achieved by the reduction of some critical field failures through better design practices. Thus, this paper shows how warranty data from customers can be utilized to have a better perception of ranking of a product compared to its competitors in the market and also to identify possible causes for making some customers dissatisfied and eventually to help percolate these issues at the design level. This closes the design cycle loop in which after a design is converted into a product, its perceived level of satisfaction by customers can also provide valuable information to help make the design better in an iterative manner. The proposed methodology is generic and novel, and can be applied to other consumer products as well.

  • 80.
    Bandaru, Sunith
    et al.
    Högskolan i Skövde, Forskningscentrum för Virtuella system. Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Ng, Amos
    Högskolan i Skövde, Forskningscentrum för Virtuella system. Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Deb, Kalyanmoy
    Department of Electrical and Computer Engineering, Michigan State University, East Lansing, USA.
    On the Performance of Classification Algorithms for Learning Pareto-Dominance Relations2014Ingår i: Proceedings of the 2014 IEEE Congress on Evolutionary Computation (CEC), IEEE Press, 2014, s. 1139-1146Konferensbidrag (Refereegranskat)
    Abstract [en]

    Multi-objective evolutionary algorithms (MOEAs)are often criticized for their high-computational costs. Thisbecomes especially relevant in simulation-based optimizationwhere the objectives lack a closed form and are expensive toevaluate. Over the years, meta-modeling or surrogate modelingtechniques have been used to build inexpensive approximationsof the objective functions which reduce the overall number offunction evaluations (simulations). Some recent studies however,have pointed out that accurate models of the objective functionsmay not be required at all since evolutionary algorithms onlyrely on the relative ranking of candidate solutions. Extendingthis notion to MOEAs, algorithms which can ‘learn’ Paretodominancerelations can be used to compare candidate solutionsunder multiple objectives. With this goal in mind, in thispaper, we study the performance of ten different off-the-shelfclassification algorithms for learning Pareto-dominance relationsin the ZDT test suite of benchmark problems. We considerprediction accuracy and training time as performance measureswith respect to dimensionality and skewness of the training data.Being a preliminary study, this paper does not include results ofintegrating the classifiers into the search process of MOEAs.

  • 81.
    Bandaru, Sunith
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Ng, Amos H. C.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    An empirical comparison of metamodeling strategies in noisy environments2018Ingår i: Proceedings of the Genetic and Evolutionary Computation Conference (GECCO-2018) / [ed] Hernan Aguirre, New York, NY, USA: ACM Digital Library, 2018, s. 817-824, artikel-id 3205509Konferensbidrag (Refereegranskat)
    Abstract [en]

    Metamodeling plays an important role in simulation-based optimization by providing computationally inexpensive approximations for the objective and constraint functions. Additionally metamodeling can also serve to filter noise, which is inherent in many simulation problems causing optimization algorithms to be mislead. In this paper, we conduct a thorough statistical comparison of four popular metamodeling methods with respect to their approximation accuracy at various levels of noise. We use six scalable benchmark problems from the optimization literature as our test suite. The problems have been chosen to represent different types of fitness landscapes, namely, bowl-shaped, valley-shaped, steep ridges and multi-modal, all of which can significantly influence the impact of noise. Each metamodeling technique is used in combination with four different noise handling techniques that are commonly employed by practitioners in the field of simulation-based optimization. The goal is to identify the metamodeling strategy, i.e. a combination of metamodeling and noise handling, that performs significantly better than others on the fitness landscapes under consideration. We also demonstrate how these results carry over to a simulation-based optimization problem concerning a scalable discrete event model of a simple but realistic production line.

  • 82.
    Bandaru, Sunith
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Ng, Amos H. C.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    On the scalability of meta-models in simulation-based optimization of production systems2015Ingår i: Proceedings of the 2015 Winter Simulation Conference / [ed] L. Yilmaz, W. K. V. Chan, I. Moon, T. M. K. Roeder, C. Macal, and M. D. Rossetti, Piscataway, NJ: IEEE Press, 2015, s. 3644-3655Konferensbidrag (Refereegranskat)
    Abstract [en]

    Optimization of production systems often involves numerous simulations of computationally expensive discrete-event models. When derivative-free optimization is sought, one usually resorts to evolutionary and other population-based meta-heuristics. These algorithms typically demand a large number of objective function evaluations, which in turn, drastically increases the computational cost of simulations. To counteract this, meta-models are used to replace expensive simulations with inexpensive approximations. Despite their widespread use, a thorough evaluation of meta-modeling methods has not been carried out yet to the authors' knowledge. In this paper, we analyze 10 different meta-models with respect to their accuracy and training time as a function of the number of training samples and the problem dimension. For our experiments, we choose a standard discrete-event model of an unpaced flow line with scalable number of machines and buffers. The best performing meta-model is then used with an evolutionary algorithm to perform multi-objective optimization of the production model.

  • 83.
    Bandaru, Sunith
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Ng, Amos H. C.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Trend Mining: A Visualization Technique to Discover Variable Trends in the Objective Space2019Ingår i: Evolutionary Multi-Criterion Optimization: 10th International Conference, EMO 2019, East Lansing, MI, USA, March 10-13, 2019, Proceedings / [ed] Kalyanmoy Deb, Erik Goodman, Carlos A. Coello Coello, Kathrin Klamroth, Kaisa Miettinen, Sanaz Mostaghim, Patrick Reed, Cham, Switzerland: Springer, 2019, Vol. 11411, s. 605-617Konferensbidrag (Refereegranskat)
    Abstract [en]

    Practical multi-objective optimization problems often involve several decision variables that influence the objective space in different ways. All variables may not be equally important in determining the trade-offs of the problem. Decision makers, who are usually only concerned with the objective space, have a hard time identifying such important variables and understanding how the variables impact their decisions and vice versa. Several graphical methods exist in the MCDM literature that can aid decision makers in visualizing and navigating high-dimensional objective spaces. However, visualization methods that can specifically reveal the relationship between decision and objective space have not been developed so far. We address this issue through a novel visualization technique called trend mining that enables a decision maker to quickly comprehend the effect of variables on the structure of the objective space and easily discover interesting variable trends. The method uses moving averages with different windows to calculate an interestingness score for each variable along predefined reference directions. These scores are presented to the user in the form of an interactive heatmap. We demonstrate the working of the method and its usefulness through a benchmark and two engineering problems.

    Publikationen är tillgänglig i fulltext från 2020-02-03 00:00
  • 84.
    Bandaru, Sunith
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Ng, Amos H. C.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Deb, Kalyanmoy
    Department of Electrical and Computer Engineering, Michigan State University, USA.
    Data mining methods for knowledge discovery in multi-objective optimization: Part A - Survey2017Ingår i: Expert systems with applications, ISSN 0957-4174, E-ISSN 1873-6793, Vol. 70, s. 139-159Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Real-world optimization problems typically involve multiple objectives to be optimized simultaneously under multiple constraints and with respect to several variables. While multi-objective optimization itself can be a challenging task, equally difficult is the ability to make sense of the obtained solutions. In this two-part paper, we deal with data mining methods that can be applied to extract knowledge about multi-objective optimization problems from the solutions generated during optimization. This knowledge is expected to provide deeper insights about the problem to the decision maker, in addition to assisting the optimization process in future design iterations through an expert system. The current paper surveys several existing data mining methods and classifies them by methodology and type of knowledge discovered. Most of these methods come from the domain of exploratory data analysis and can be applied to any multivariate data. We specifically look at methods that can generate explicit knowledge in a machine-usable form. A framework for knowledge-driven optimization is proposed, which involves both online and offline elements of knowledge discovery. One of the conclusions of this survey is that while there are a number of data mining methods that can deal with data involving continuous variables, only a few ad hoc methods exist that can provide explicit knowledge when the variables involved are of a discrete nature. Part B of this paper proposes new techniques that can be used with such datasets and applies them to discrete variable multi-objective problems related to production systems. 

  • 85.
    Bandaru, Sunith
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Ng, Amos H. C.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Deb, Kalyanmoy
    Department of Electrical and Computer Engineering, Michigan State University, USA.
    Data mining methods for knowledge discovery in multi-objective optimization: Part B - New developments and applications2017Ingår i: Expert systems with applications, ISSN 0957-4174, E-ISSN 1873-6793, Vol. 70, s. 119-138Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The first part of this paper served as a comprehensive survey of data mining methods that have been used to extract knowledge from solutions generated during multi-objective optimization. The current paper addresses three major shortcomings of existing methods, namely, lack of interactiveness in the objective space, inability to handle discrete variables and inability to generate explicit knowledge. Four data mining methods are developed that can discover knowledge in the decision space and visualize it in the objective space. These methods are (i) sequential pattern mining, (ii) clustering-based classification trees, (iii) hybrid learning, and (iv) flexible pattern mining. Each method uses a unique learning strategy to generate explicit knowledge in the form of patterns, decision rules and unsupervised rules. The methods are also capable of taking the decision maker's preferences into account to generate knowledge unique to preferred regions of the objective space. Three realistic production systems involving different types of discrete variables are chosen as application studies. A multi-objective optimization problem is formulated for each system and solved using NSGA-II to generate the optimization datasets. Next, all four methods are applied to each dataset. In each application, the methods discover similar knowledge for specified regions of the objective space. Overall, the unsupervised rules generated by flexible pattern mining are found to be the most consistent, whereas the supervised rules from classification trees are the most sensitive to user-preferences. 

  • 86.
    Bandaru, Sunith
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Smedberg, Henrik
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    A parameterless performance metric for reference-point based multi-objective evolutionary algorithms2019Ingår i: GECCO '19: Proceedings of the Genetic and Evolutionary Computation Conference / [ed] Manuel López-Ibáñez, New York, NY, USA: ACM Digital Library, 2019, s. 499-506Konferensbidrag (Refereegranskat)
    Abstract [en]

    Most preference-based multi-objective evolutionary algorithms use reference points to articulate the decision maker's preferences. Since these algorithms typically converge to a sub-region of the Pareto-optimal front, the use of conventional performance measures (such as hypervolume and inverted generational distance) may lead to misleading results. Therefore, experimental studies in preference-based optimization often resort to using graphical methods to compare various algorithms. Though a few ad-hoc measures have been proposed in the literature, they either fail to generalize or involve parameters that are non-intuitive for a decision maker. In this paper, we propose a performance metric that is simple to implement, inexpensive to compute, and most importantly, does not involve any parameters. The so called expanding hypercube metric has been designed to extend the concepts of convergence and diversity to preference optimization. We demonstrate its effectiveness through constructed preference solution sets in two and three objectives. The proposed metric is then used to compare two popular reference-point based evolutionary algorithms on benchmark optimization problems up to 20 objectives.

    Publikationen är tillgänglig i fulltext från 2020-08-01 00:00
  • 87.
    Barlas, Sofia
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Buerba, Adriana
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Analyze, consolidate and improve the product development process at Parker Hannifin QCDE through implementation of DFMA principles2017Självständigt arbete på grundnivå (kandidatexamen), 15 poäng / 22,5 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Parker Hannifin QCDE aim to eliminate as much wasted time, materials and resources as achievable by implementing Design for Manufacturing and Assembly principles into a modified version of their Product Development Process. The modified Product Development Process was developed within this project with the objective of aiding the company to remain competitive within their field, as well as continue to efficiently develop and produce high quality products.

     

    A literature study was performed to gain a greater understanding of the multiple Design for Excellence methods and their possibilities to enhance the Product Development Process at Parker Hannifin QCDE. The literature study included various sources such as academic books and scientific articles.

     

    An empirical study was conducted and the use of the current Internal Product Development Process was evaluated in conjunction with a detailed evaluation of the designated coupling. An additional aspect that was explored includes an evaluation of the extent of Design for Manufacturing and Assembly that is implemented into the current Internal Product Development Process.

     

    The Generation chapter of this thesis outlines the sequence and process implemented for generating the modified Internal Product Development Process and implementing Design for Manufacturing and Assembly. The results of this thesis project included implementing Design for Manufacturing and Assembly in the form of checklists. The multiple Design for Excellence checklists were inspired in part by the information obtained from the literature study and the authors interpretation. The finished concept has been provided to Parker Hannifin QCDE in the form of a pamphlet including instructions of how to implement the checklists into the modified Internal Product development process.

     

    The discussion chapter within this report consists of a conclusion and deliberation regarding the methodology used within this thesis. The results obtained from this thesis have been dissected and evaluated along with implications and potential weaknesses in the work.

  • 88.
    Barrera Diaz, Carlos Alberto
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Volvo Cars Corporation Skövde.
    Discrete event simulation data management2016Självständigt arbete på avancerad nivå (magisterexamen), 15 poäng / 22,5 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Simulation is one of the most important decision support tools that has been present during decades in the manufacturing industry. Discrete Event Simulation (DES) experiments analysis is an important engineering activity for efficient production. In order to improve this efficiency, many companies must develop a supporting framework, between engineers and the process information. Within DES it is also important the model provenance information because it validates the credibility of the model to be reused. Therefore, nowadays there is a great interest in the simulation community based on the reusability of the simulation models. The engineers at Volvo Cars Corporation (VCC) who work with DES technology, request and deliver a high number of Key Performance Indicators (KPIs). As a consequence it is difficult to present the simulation results in a standardized way. This thesis has investigated a way to reduce and standardize this time consuming process. Thus, by the study of what information and data must be documented and how it must be presented, the main goal of this thesis was to improve the efficiency of a company, when a DES project is being developed. A survey based on VCC simulation projects, was undertaken with the aim to find the output data and the information that must be included in a standardized report. First, the information of the projects was categorized in three main groups: general information, input data and output data. Within these groups, the provenance metadata which allows the reuse of the DES project, was identified. Then, after the analysis of 23 reports from DES projects, most frequent scenarios and their related output data were identified. All the findings were used for the implementation of a standardized and automated data-handling system which simplify the project documentation task to the engineers. This data-handling system exports the key output data from the simulation software to the report designed. Validation interviews show a strong acceptance among the engineers at VCC. Finally, in order to properly keep in track with all the provenance information when a DES project is being performed, a management method was proposed as well.

  • 89.
    Barrera Diaz, Carlos Alberto
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Oscarsson, Jan
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Lidberg, Simon
    Volvo Car Corporation, Skövde, Sweden.
    Sellgren, Tommy
    Volvo Car Corporation, Skövde, Sweden.
    A Study of Discrete Event Simulation Project Data and Provenance Information Management in an Automotive Manufacturing Plant2017Ingår i: Proceedings of the 2017 Winter Simulation Conference / [ed] W. K. V. Chan, A. D’Ambrogio, G. Zacharewicz, N. Mustafee, G. Wainer, E. Page, IEEE, 2017, , s. 12s. 4012-4023Konferensbidrag (Refereegranskat)
    Abstract [en]

    Discrete Event Simulation (DES) project data management is a complex and important engineering activity which impacts on an organization’s efficiency. This efficiency could be decreased by the lack of provenance information or the unreliability of existing information regarding previous simulation projects, all of which complicates the reusability of the existing data. This study presents an analysis of the management of simulation projects and their provenance data, according to the different types of scenarios usually found at a manufacturing plant. A survey based on simulation projects at an automotive manufacturing plant was conducted, in order to categorize the information regarding the studied projects, map the available provenance data and standardize its management. This study also introduces an approach that demonstrates how a structured framework based on the specific data involved in the different types of scenarios could allow an improvement of the management of DES projects.

  • 90.
    Barrera Diaz, Carlos Alberto
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Oscarsson, Jan
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Lidberg, Simon
    Manufacturing Engineering, Research and Simulation, Volvo Car Corporation, Skövde, Sweden.
    Sellgren, Tommy
    Manufacturing Engineering, Research and Simulation, Volvo Car Corporation, Skövde, Sweden.
    Discrete Event Simulation Output Data-Handling System in an Automotive Manufacturing Plant2018Ingår i: Procedia Manufacturing, E-ISSN 2351-9789, Vol. 25, s. 8s. 23-30Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Discrete Event Simulation is a comprehensive tool for the analysis and design of manufacturing systems. Over the years, considerable efforts to improve simulation processes have been made. One step in these efforts is the standardisation of the output data through the development of an appropriate system which presents the results in a standardised way. This paper presents the results of a survey based on simulation projects undertaken in the automotive industry. In addition, it presents the implementation of an automated output data-handling system which aims to simplify the project’s documentation task for the simulation engineers and make the results more accessible for other stakeholders.

  • 91.
    Beheshtinia, Mohammad Ali
    et al.
    Department of Industrial Engineering, University of Semnan, Iran.
    Ahmadi, Bahar
    Department of Industrial Engineering, University of Semnan, Iran.
    Fathi, Masood
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    A Genetic Algorithm with Multiple Populations to Reduce Fuel Consumption in Supply Chain2019Ingår i: International Journal of Transportation Engineering, ISSN 2322-259XArtikel i tidskrift (Refereegranskat)
    Abstract [en]

    Reducing fuel consumption by transportation fleet in a supply chain, reduces transportation costs and consequently, the product final cost. Moreover, it reduces environmental pollution, and in some cases, it helps governments constitute less subsidies for fuels. In this paper, a supply chain scheduling is studied, with the two objective functions of minimizing the total fuel consumption, and the total order delivery time. After presenting the mathematical model of the problem, a genetic algorithm, named Social Genetic Algorithm (SGA) is proposed to solve it. The proposed algorithm helps decision makers determine the allocation of orders to the suppliers and vehicles and production and transportation scheduling to minimize total order delivery time and fuel consumption. In order for SGA performance evaluation, its results are compared with another genetic algorithm in the literature and optimal solution. Finally, a sensitivity analysis is performed on SGA. The results of comparisons also show the high performance of SGA. Moreover, by increasing the number of suppliers and vehicles and decreasing the number of orders, the value of the objective function is reduced.

  • 92.
    Bentabol Muñoz, Emilio
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Bosque Ibáñez, Carlos
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    González Ruiz, Pedro
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Hurtado de Mendoza, Jose Manuel
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Ruiz Zúñiga, Enrique
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Linking Wise-ShopFloor to an ABB IRB-140 Robot: Remote control, monitoring, and programming of an ABB robot IRC 5 through the internet2010Självständigt arbete på grundnivå (kandidatexamen), 15 poäng / 22,5 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The aim of this project is integrate the new robot IRB140 from ABB inside the application Wise ShopFloor (Web-based integrated sensor-driven e-ShopFloor) and the integration of a web camera inside the application as well. In order to integrate the ABB IRB140 inside the application, a Java 3D model has to be created, the kinematics and collision constrains have to be defined also and the GUI application modified to fit the virtual model and the camera inside the application. The user has to be able to jog the web camera and zoom it. Changes in the server side have been done in order to introduce new functionalities such as the sessions management, the communication mechanism now is more general using Java inheritance.

  • 93.
    Bergh, Eric
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Niklasson, Ludwig
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Konstruktion av förvaringsenhet för transport av bearbetningsverktyg2019Självständigt arbete på grundnivå (kandidatexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Brodit är en producerande industri som utvecklar utrustning för mobila enheter där konstruktion, bearbetning, montering och försäljning av produkter förekommer. För att optimera bearbetningsprocessen vill Brodit införa automatiserade system som standardiserar hantering, transport och installation av CNC-verktyg.

    Projektets huvudmål definierades till att ta fram ett förslag på en standardiserad förvaring och transportlösning. Resultatet presenteras med hjälp av en CAD-modell som visualiserar det slutgiltiga konceptet och dess delstrukturer. Frekvens- och hållfasthetsanalyser har utförts med finita element metoden för att säkerställa kvalitet och minimera risker med konstruktionen. Diskussion om kvarvarande oklarheter gällande automatiseringsaspekter, alternativa lösningar och övriga omkringliggande faktorer fördes. Som slutsats jämförs de mål som initialt sattes för projektet med de resultat som uppnåddes. Förslag på framtida utvecklingsområden och fortsatt arbete listades.

  • 94.
    Berglund, Marcus
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Karlgren, Martin
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    DEVELOPING A FURNITURE TEST MACHINE ACCORDING TO NATIONAL STANDARDS: ENSURING QUALITY AND CREDIBILITY FOR THE SMEES IN SOUTH AFRICA2019Självständigt arbete på grundnivå (kandidatexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    In South Africa where the unemployment is immense, Small Micro and Medium enterprises (SMMEs) provide more than half of all job opportunities. Furntech, a non-profit organisation that works with vocational training and incubation within the furniture manufacturing sector in South Africa, wants to expand their testing laboratory with a machine to test mattresses according to local standards. The aim of this project is to develop a machine design to test innerspring mattresses by using product development methodology. Observations, interviews, and visits at companies in the furniture manufacturing sector is conducted to understand the needs from the user- and mechanical aspects. Existing and required additional parts to support the functionality for the test bedding machine has been evaluated by calculations and simulations by using for example ABAQUS and JACK.

    A design is produced that meets the local standards by developing the existing table test machine in Furntech’s laboratory and is presented in a CAD-model. A scissor lift controls the vertical adjustment of the platform and an electric ball screw cylinder controls the compression of the mattresses. Instruction manuals, a graphical interface design, flowcharts and drawings of some of the parts has also been produced.

  • 95.
    Bergman, Christian
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Högberg, Dan
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Bäckstrand, Gunnar
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system. Swerea IVF AB, Gothernburg, Sweden.
    Moestam, Lena
    Volvo Group Trucks Operations, Gothenburg, Sweden.
    A Library Based Tool to Assist the Generative Activity in Workstation Design2014Ingår i: Advances in Ergonomics in Design, Usability & Special Populations: Part II / [ed] Francisco Rebelo and Marcelo Soares, AHFE Conference , 2014, s. 206-214Konferensbidrag (Refereegranskat)
  • 96.
    Bergman, Christian
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Ruiz Castro, Pamela
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Högberg, Dan
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Hanson, Lars
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system. Scania AB, Södertälje, Sweden.
    Implementation of Suitable Comfort Model for Posture and Motion Prediction in DHM Supported Vehicle Design2015Ingår i: Procedia Manufacturing, ISSN 2351-9789, Vol. 3, s. 3753-3758Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Driver-vehicle interaction analyses are done to ensure a successful vehicle design from an ergonomics perspective. Digital Human Modelling (DHM) tools are often used to support such verifications, particularly at early stages of the product development process. When verifying that a vehicle design accommodates the diversity of users and tasks, a DHM tool needs to be able to represent postures and motions that are likely under certain conditions. This functionality is essential so that the tool user will obtain objective and repeatable simulation results. The DHM tool IMMA (Intelligently Moving Manikins) predicts postures and motions by using computational methods. This offers the possibility to generate postures and motions that are unique for the present design conditions. IMMA was originally developed for simulating manual assembly work, whereas the work presented here is a step towards utilizing the IMMA tool for occupant packaging and related tasks. The objective is a tool for virtual verification of driver-vehicle interaction that supports and automates the simulation work to a high degree. The prediction functionality in IMMA is based on the use of optimization algorithms where one important component is the consideration of comfort level. This paper reports results from an basic investigation of driving postures and available comfort models suitable in a driving context, and shows initial results of seated posture and motion prediction functionality in the IMMA tool.

  • 97.
    Bergman, Christian
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Ruiz Castro, Pamela
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Högberg, Dan
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Hanson, Lars
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system. Industrial Development, Scania CV, Sweden.
    Implementation of Suitable Comfort Model for Posture and Motion Prediction in DHM Supported Vehicle Design2015Ingår i: Proceedings of the 6th International Conference on Applied Human Factors and Ergonomics (AHFE 2015), AHFE , 2015Konferensbidrag (Refereegranskat)
    Abstract [en]

    Driver-vehicle interaction analyses are done to ensure a successful vehicle design from an ergonomics perspective. Digital Human Modelling (DHM) tools are often used to support such verifications, particularly at early stages of the product development process. When verifying that a vehicle design accommodates the diversity of users and tasks, a DHM tool needs to be able to represent postures and motions that are likely under certain conditions. This functionality is essential so that the tool user will obtain objective and repeatable simulation results. The DHM tool IMMA (Intelligently Moving Manikins) predicts postures and motions by using computational methods. This offers the possibility to generate postures and motions that are unique for the present design conditions. IMMA was originally developed for simulating manual assembly work, whereas the work presented here is a step towards utilizing the IMMA tool for occupant packaging and related tasks. The objective is a tool for virtual verification of driver-vehicle interaction that supports and automates the simulation work to a high degree. The prediction functionality in IMMA is based on the use of optimization algorithms where one important component is the consideration of comfort level. This paper reports results from an basic investigation of driving postures and available comfort models suitable in a driving context, and shows initial results of seated posture and motion prediction functionality in the IMMA tool.

  • 98.
    Bergman, Emil
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Wikström, Anna
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Påkörningsskydd i bearbetningsfabriker: Utveckling av påkörningsskydd för industrifordon2015Självständigt arbete på grundnivå (kandidatexamen), 15 poäng / 22,5 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    I en stor del av arbetsolyckor som anmäls är en truck inblandad. För att undvika att fotgängare blir påkörda av industrifordon används ofta påkörningsskydd. På Volvo Group Truck Operations i Skövde används idag påkörningsskydd i fabrikerna för att avgränsa fotgängare från fordonstrafiken. Volvos påkörningsskydd är en helsvetsad stålkonstruktion som är fäst i betonggolvet med expanderbultar. Dessa påkörningsskydd är byggda efter platsen de monteras på och är därför svåra att återanvända och reparera. Volvo har efterfrågat en principkonstruktion av ett moduluppbyggt påkörningsskydd för att underlätta framförallt återanvändning av dem. Hållfasthetsberäkningar utförs för att säkerställa att kravspecifikationen uppfylls.

    För att kunna utföra arbetet görs en litteraturstudie där befintliga lösningar, infästningsmetoder i betong, beräkningsmetoder, säkerhetskrav och en produktutvecklingsmetod studeras. Observationer och intervjuer genomförs för att ta fram en kravspecifikation. Observationer visade att vid en kollision lossnar infästningen till golvet för att det befintliga påkörningsskyddet är för robust. Med kravspecifikationen som bas utförs konceptgenerering. De framtagna koncepten utvärderas och vidareutvecklas i flera omgångar parallellt med att kravspecifikationen förfinas. En moduluppbyggd principkonstruktion med två olika infästningsalternativ presenteras. Tanken med princip­konstruktionen är att det skall dimensioneras för att ge vika vid infästningens maxlast. Hållfasthetsberäkningar, som utförts på de mest kritiska komponenterna, visar att det är svårt att dimensionera påkörningsskyddet för att säkerställa att rätt del går sönder vid en påkörning. En Failure Mode and Effects Analysis utförs för att identifiera eventuella brister på principkonstruktionen och ta fram förslag på hur dessa kan åtgärdas.

    Principkonstruktionen uppfyller de delar av kravspecifikationen som går att kontrollera i nuläget. Dessa krav är att principkonstruktionen är moduluppbyggd, lätt att demontera, reparera och återanvända, lätt att förvara och att den uppfyller säkerhetskraven.

    Vidare arbete med hållfasthetsberäkningar på och dimensionering av principkonstruktionen rekommenderas. För att säkerställa att kravspecifikationen är uppfylld och att påkörningsskyddet beter sig som önskat vid en påkörning bör prototyper tillverkas. 

  • 99.
    Bergstedt, Pontus
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Svemark, Viktor
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Konstruktion av stegmatare för vevstakar2019Självständigt arbete på grundnivå (kandidatexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Detta arbete beskriver förarbete och konstruktion av en stegmatare som sorterar och orienterar vevstakar för en takttid på tio sekunder. Industrier är ofta beroende av materialhanteringsutrustning där olika processer säkerställer någon form av sortering eller orientering, vilket styrker arbetets relevans. Detta har skett genom att dela in maskinen i två huvudfunktioner; trappfunktionen, som försorterar och transporterar vevstakarna vidare till andra huvudfunktionen; orienteringsfunktionen, där orienteringen sker.

    Genom att tillämpa metoder inom; konstruktion & tillverkning, feleffektsanalys och programvaror för materialdatabashantering, datastödd design, samt numerisk hållfasthetsanalys kunde en konstruktion utformas som speglar de aspekter som kännetecknar en genomtänkt produkt. Sju olika designmetoder användes för att generera och utvärdera idéer i flera itererande steg. Tio undersökande experiment utfördes som ytterligare utvärdering av koncept samt underlag för vidare beräkningar och slutsatser.

    Utformningen av stegmataren resulterade i en enkelverkande lutande trapp med två rörliga trappsteg och ett statiskt mellan dem för överföring. En enkelmatning efter trappen i form av ett “skovelhjul” säkerställer att vevstakarna levereras en-och-en till orienteringsfunktionen samtidigt som den garanterar takttiden. En orienteringsfunktion bestående av ett “rullband” som med hjälp av friktion och tyngdpunktsförskjutning orienterar vevstakarna med vevänden först. Slutligen studerades tre kritiska områden i konstruktionen för vidare analys med finita element-metoden med godkända resultat.

    Samtliga mål för projektet uppnåddes, exempelvis har stegmataren färre unika komponenter än befintliga lösningar. Ambitionen var att utforma stegmataren med en låg grad av komplexitet och utan sensorer har genomsyrat hela projektet, vilket även har uppnåtts.

  • 100.
    Bermúdez Román, Abel
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Gaztelumendi Arriaga, Javier
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Building and programming an autonomous robot using a Raspberry Pi as a PLC2016Självständigt arbete på grundnivå (kandidatexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    PLC programming students are often limited to simulated systems or soft PLCs, because the high price of the hardware and the software licenses make it difficult for faculties to use real equipment for teaching. This paper describes the design and building of a PLC controlled self-balancing robot with CodeSys and Raspberry Pi as a low-cost demonstrator model that students can use as a base to interact with a real system. A first prototype has been developed, which can be used in the future to get students involved in beginner automation courses without having to build a system from scratch.

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