his.sePublications
Change search
Refine search result
1234567 101 - 150 of 471
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 101.
    Bäck, Gustaf
    et al.
    University of Skövde, School of Engineering Science.
    Wall, Gustaf
    University of Skövde, School of Engineering Science.
    Effektiv Materialhantering: Konstruktion och hållfasthetsberäkning av materialhanteringslösning2014Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The company Furhoffs Rostfria AB located in Skövde has developed a new assembly method for kitchen-sinks. The method means a more effective assembly of kitchen-sinks but the transportation of the material to be assembled is still a moment requiring a lot of time. The goal of this work is to develop a material handling concept that facilitates this transport. To confirm the achievement of the set goal, a number of more specific goals are also set. These goals should be achieved for the most optimal solution regarding the number of work moments, time regarding usage, general requirements from the Swedish Work Environment Authority and requirements regarding sustainable development.

    To understand the functions that the concept should fulfill and to understand the ingoing parameters, a literature study is performed. The study is based on a number of sources including current scientific articles which represents the foundation regarding the method for sustainable development. Web sources, books with technical character and knowledge from Furhoffs Rostfria AB are used as a foundation for the remaining methods performed. The final concept satisfies four functions, to transport, to lift, to hold and to assort ingoing material.

    Different basic concepts are produced by using three different methods of generation of concepts, where different competences are included. A weighted concept selection matrix is used to select which concept that should be analyzed further. The chosen concept is analyzed regarding; the risk of tipping, items placed on the concept sliding around and the strength and the mechanics of the concept.

    The material strength analysis, performed by using the finite element method, evaluates acting moments, acting effective stresses and deformation of the concept. The concept is evaluated by creating a beam element analysis and by creating a shell element analysis. The conclusion from these analyzes is that, regarding the practical usage of the concept, an insignificant deformation is obtained. Regarding occurring effective stresses a safety factor of barely two is obtained compared to the yield limit of the chosen material.

    The concept fulfills all the goals and demands set and is evaluated as a functioning solution for the stated problem. Suggestions regarding further future improvements for the chosen concept are provided.

  • 102.
    Bäckstrand, Gunnar
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Intuitiv montering2012In: Teknik och tillväxt, no 2, p. 24-24Article in journal (Other (popular science, discussion, etc.))
  • 103.
    Calestam, Magnus
    et al.
    University of Skövde, School of Technology and Society.
    Wedin, Johan
    University of Skövde, School of Technology and Society.
    Bucklingsanalys av spannmålssilo2013Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Grains with varying humidity can be stored in square silos with wall elements consisting of corrugated sheet. When the stored grain is to be emptied from the silos it has tendency to stick to the walls, especially if humid, which means that the grain must be removed manually. To avoid this time-consuming process a flat sheet is mounted on the corrugated sheet to prevent the moist grain from sticking to the wall. If the same dimension on the corrugated sheet is used when the flat sheet is or is not mounted the walls may be subjected to buckling. This thesis is thus about how the wall elements shall be designed in order to prevent buckling. The silos that have been examined have a cross section of 3.0 x 3.0 m and 2.5 x 2.5 m respectively with wall elements consisting of only corrugated sheet or smooth sheet mounted on corrugated sheet. Furthermore, the silos got vertical walls with a height of 8.4 m consisting of ten sections. Calculations are made with wheat as the stored grain.

     

    To be able to dimension the wall elements the pressure is calculated for the different silos, using the Swedish and European standard Eurocode (2006), EN 1991-4 for pressure calculations in silos and tanks. To calculate the pressure the silos are assigned into action assessment class 1, since their capacity are less than a 100 tons, which further means that the unsymmetrical pressure can be ignored. The silos are also classified as slender. As the silos outlet consists of a square pyramidal hopper with centric outlet and a half internal angel of 45° an inner pipe flow occurs during emptying. This means according to Eurocode that the dimension shall be based on the pressure which occurs during filling. The horizontal and vertical pressure and the pressure made from the friction are calculated for the different cross sections.

     

    The CAD software Pro Engineer and the finite element extension Mechanica is used to model the current silos and perform analysis for stress and buckling. The models have four symmetry planes therefore only one eighth of the current structure is modeled, corresponding to half a wall element and half a pole. The models are created as shell models and boundary conditions are applied in all symmetrical planes and on the top and bottom of the pole. The structure of the silos is simplified since no screws or radius is modeled. The pressure calculated according to Eurocode is converted into forces and applied to the models. The whole structure is modeled in steel with yield strength of 180 MPa.

     

    The company’s older dimension standards are applied on the wall elements and analyzed. To investigate where to most critical areas for buckling occurs a buckling analysis based on a static analysis of the models is performed. The results from the buckling analysis for the silo wall element consisting of corrugated sheet with the width of 3.0 m shows that buckling occurs on the second bottom section at 72 % of the applied force. For the silo consisting of the same wall element but with the width of 2.5 m buckling occurs at the top section where the buckling force amounts to 62 % of the applied force. For the silos with wall elements consisting of plain sheet mounted on corrugated sheet buckling occurs at 3-4 % of the applied force for the two wall widths. Analysis show that the low values of buckling load on the plane sheet is a result from local buckling. In order to dimension the corrugated sheet to prevent it from buckling when the plane sheet is mounted a free body diagram is made for the corrugated sheet to obtain the acting forces. The buckling analysis of the corrugated sheet, with wall width 3.0 m, which is pressurized by the plane sheet shows that buckling occurs on the silos second bottom section. Buckling occurs at 59 % of the applied force for the silo with wall width of 2.5 m buckling occurs at 51 % of the applied force on the silo top section.

     

    Since the goal is that the corrugated sheets are not to be subject to buckling, the thickness of the sheets is iterated until the buckling force is equal to at least 110 % of the applied force. This generates an increased thickness for the lower four sections for the silo with wall element consisting of corrugated sheet with wall width of 3.0 m. For the silo with the same wall elements but with a wall width of 2.5 m, the dimensions of the top two sections need to increase. Regarding the silos with wall elements consisting of plane sheet mounted on corrugated sheet an increase in dimension is needed for the corrugated sheet for the five lowest sections for the wall width of 3.0 m.

     

    With a wall width of 2.5 m the same dimension can be used as when the silo wall elements consist of only corrugated sheet. If the plane sheet is not to be exposed for buckling the thickness of the sheets needs to be increased from between 5.5 mm and 1.5 mm. All calculations of the sheet dimensions are obtained by a conservative thinking which means that the company’s older dimensions may be correct. However, the resulting dimensions are reasonable for the corrugated sheets.

     

  • 104.
    Campillo, Jose
    et al.
    University of Skövde, School of Engineering Science.
    Garcia, Celia
    University of Skövde, School of Engineering Science.
    Creating a pleasurable aluminium packaging2015Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This project has been carried out in collaboration with CC Pack, a Swedish packaging company located in Tibro, and under the supervision of University of Skövde.

    The aim of the project is the creation of a new aluminium packaging, with the intention of satisfying the highest number of customers' requirements, getting also a differentiation from the competitors.

    Archer’s model is followed during the design process. This model allows strengthening the efficiency of project design.

    The compilation of information in order to make a complete requirement classification is based on: CC Pack requirements, a study of customer needs focused on interviews and pilot study, and a literature study lead by Maslow’s hierarchy translated to design along with the 4 pleasures of Patrick Jordan.

    After the requirements classification, it is time to start with the concept generation phase. This phase consist of diverse methods of generation and evaluation of ideas, such as brainstorming or the weighted objective method, until a final solution is reached.

    This last solution, which consists of an aluminium tray surrounded by a cardboard structure, is communicated at the end of the project through illustrations created through design software such as PTC Creo Parametric and Photoshop.

    Conclusions obtained are quite positive in general, nevertheless there is still an aspect that could be improved. It is related to the shipping system and it is commented in chapter 7 conclusions.

    There is also a chapter devoted to propose possible future contributions in order to implement this project.

  • 105.
    Carlberger, Thomas
    University of Skövde, School of Technology and Society.
    Impact Simulation of Adhesively Joined Structures2006Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The development of competitive and crashworthy automotive car bodies has reached so far that the manufacturers no longer rely on mono-material steel structures. Improved strength/weight performance may be achieved by using optimal material in each part of the car structure, leading to bi-material joints and ruling out spot welding; the common joining method during the past half century of automotive history. Adhesive bonding is an attractive joining method, not only capable of managing dissimilar materials, but also capable of improving stiffness and strength in monomaterial structures. Moreover, the joints do not need additional sealing and there may be cost savings using adhesive bonding. Impact simulation of car structures is mostly performed using an explicit FE-method. This method has an inherent stability criterion: the time step used may not exceed the stable time step, or critical time step, Δtc. In this thesis, a simplified cohesive zone model is studied. It is implemented into an explicit FE-code and compared to a closed form solution. The FE-solutions agree with the closed form solutions. It is found that the evolution of damage in the adhesive layer may stop under certain conditions that are likely to occur in a real structure. It is shown that an explicit FE-analysis with a “large” time step is more prone to give immediate rupture. Thus, the method is conservative. An interphase element formulation is derived for a 2D-adhesive joint model, joining beam adherends. It is shown that the mass matrix of the interphase element gives a small contribution to the mass matrix of the structure. However, this contribution is positive for the numerical stability of the explicit FE-method and it is recommended to keep this matrix in the analysis. Moreover, it is concluded that the contribution of material damping of the adhesive layer can be neglected as compared to the effects of plasticity of the adherends. The interphase element formulation is used to analyse the Double Cantilever Beam specimen. The results are compared to an alternative model using continuum elements. The comparison shows substantially faster convergence and shorter execution time for the interphase formulation. A rough estimate indicates fifteen times shorter execution time using the interphase elements in a realistic structure.

  • 106.
    Carlberger, Thomas
    et al.
    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.
    Vilka hållfasthetsegenskaper har limfogen?: Simulering på Högskolan i Skövde ger svaren2014In: Fordonskomponenten, ISSN 2000-7299, no 3, p. 46-47Article, review/survey (Other (popular science, discussion, etc.))
    Abstract [sv]

    Att beräkna limfogars hållfasthet är inte helt enkelt, vilket beror på spänningskoncentrationens inflytande vid limfogens kanter.

    Materialmekanik vid Högskolan i Skövde har specialiserat sig på hållfasthetssimulering av limfogar genom kohesiv modellering.

  • 107.
    Carlsson, Annika
    University of Skövde, School of Engineering Science.
    Kapacitetsanalys av produktionsflöde: - Med hjälp av produktionssimulering och traditionella produktionstekniska verktyg2014Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Volvo GTO in Skövde belongs to manufacturing and supply engines for truck customers worldwide. All engines to be sent for export goes through a production flow, CBU-line. CBU-line is an assembly line that not since construction in 1996 has undergone any major layout changes of substance, although the details of the flow changed. The object of the project is that by analyzing access conditions in order to determine the flow capacity and to produce focus areas for future improvement efforts.

    The flow lacks a large amount of the production engineering data necessary to assess its capabilities. Based on this a number of methods have been used together to create a picture of the current state of flow. Methods such as time study, work-study and AviX study have been conducted to identify bottlenecks in flow. While it is clear how much work is categorized in value-added in whole flow and per station. In addition to these traditional production engineering tools, there have been a production simulation. Implemented analyzes consistently shows a common bottleneck in the production flow which becomes the focus of improvement efforts.

    Through simulation analysis, the flow technical capacity estimated to be approximately 40 % higher than the throughput that occurs in the flow today. Simulation Analysis based on one developed suggestion for improvement indicates a potential increase of 32 %. To create the conditions to achieve this requires systematic efforts to reduce the effect of interference and wastage in the flow comprising over 70 % of all activity in the flow. The work has proposed that with relatively simple means to reduce bottleneck and increase throughput through the flow.

  • 108.
    Carlsson, Linnéa
    University of Skövde, School of Technology and Society.
    Design av lättöppnad färdigmatsförpackning: Inriktning hållbar utveckling2013Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    A development of an environmentally friendly, ready meals packaging, that is easy to open for people suffering from rheumatoid arthritis, has been performed in cooperation with CC Pack in Tibro. The package is intended for use in elderly care home services. The development work was mainly done by focus group surveys and tests of function models. A life cycle analysis with reference in the current plastic trays used in home care in Skövde was conducted to find out which of the two final concepts was the most eco-friendly. Evident in interviews and site visits was that a rounder and more colorful packaging was desired. A simple oval tray with a hard cardboard flap solved the problem of opening difficulties, both by the position of the hard flap and also with an elongated shape.

  • 109.
    Carrera Artola, Iosu
    et al.
    University of Skövde, School of Engineering Science. Mondragon Unibertsitatea.
    Lucena Garcerán, Alejandro
    University of Skövde, School of Engineering Science. University of Málaga .
    Detection of Frazil Ice at Water Intakes at Träbena Power Station2014Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Frazil ice is a phenomenon that takes place in cold regions when the water of rivers, lakes or oceans is cooled under 0ºC. Several times during winter, frazil ice can appear at river Ätran, where Träbena hydropower plant is held by the company Wetterstad Consulting AB. Frazil ice particles contained in the flowing water are extremely sticky and adhere to any object placed in the water. Trash racks are used by the power plant at the water intakes to prevent any strange object to go into the turbines. However, frazil ice particles stick to the trash racks creating an ice blockage that interrupts the water inflow. In this situation, the power plant has to stop the production even for several months, due to the lack of water that reaches the turbines. In order to solve this problem, the company has installed a heating system on the trash racks that prevent the adhesion of frazil ice particles. This system is manually operated, and it is turned on or off based on the experience and predictions of the company. This heating system is very power consuming and every time it is turned on unnecessarily the company loses money. An automatic frazil ice detection system that turns on the heating system when needed is to be created. For that, several options have been analysed, and finally a capacitor-based sensor has been developed as a solution. The sensor consist of two steel plates coated with semi-transparent polycarbonate submerged underwater parallel placed in the space between the trash racks’ bars, forming this way a parallel plate capacitor. The capacitance of a capacitor depends exclusively on its geometry and the dielectric material between the plates. Hence when the water temperature is low enough, frazil ice particles stick to the plates of the capacitor and its capacitance will vary indicating that the accretion of frazil ice may block the water inflow. This variation is registered and a signal is send to the heating system to start operating. This way, the heating system is completely automated; no human intervention is needed at all.

  • 110.
    Cedenkvist, Kristin
    University of Skövde, School of Engineering Science.
    Utveckling av ett nytt ändbeslag för spinnakerbom2016Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    In this project a product development has been made of a spinnaker pole end fitting. The project has been made in cooperation with Seldén Mast AB; a company that is manufacturing sailing rigs and that is located in Gothenburg.

     

    The project has been following a design process that is inspired from Archer’s three-phase model, which consists of an analytical part, a creative part and an executive part. The project started with an extensive pre-study that contained a market analysis of existing fittings today and interviews with users. After the pre-study the concept generation started with a Brainstorming session and then continued with more structured methods as the Idea generator and Contrast thinking. The methods resulted in three different concepts that were presented for Seldén. These concepts were then made as CAD-models as well.

     

    The concept selection started with a questionnaire that was sent out to the user-group where the three different concepts were presented. Next selection method was The Weighted Objective Method. It was the same concept that was chosen in both methods and after some discussions with Seldén a final decision could be made.

     

    The project resulted in a fitting that has a softer, rounder shape and a more simple design than the fittings Seldén are using today. The new concept also had a more effective tripp trigger-solution and a design that will release the rope in a more simple way. On the back of the fitting a shock-absorber was placed in the shape of a rubber-plate.

  • 111.
    Chiet, Cheong Wen
    et al.
    Universiti Tunku Abdul Rahman, Malaysia.
    Ching, Ng Tan
    Universiti Tunku Abdul Rahman, Malaysia.
    Huat, Saw Lip
    Universiti Tunku Abdul Rahman, Malaysia.
    Fathi, Masood
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Tzuu, Tan Jaw
    Universiti Tunku Abdul Rahman, Malaysia.
    The Integration of Lean and Green Manufacturing for Malaysian Manufacturers: A Literature Review to Explore the Synergies between Lean and Green Model2019In: International Conference on Sustainable Energy and Green Technology 2018 / [ed] Chong Wen Tong, Wang Chin-Tsan, Bernard Saw Lip Huat, Institute of Physics Publishing (IOPP), 2019, Vol. 268, article id 012066Conference paper (Refereed)
    Abstract [en]

    In general, profitability and efficiency have been the main interest for organization. However, the increasing concerns for the environment from government, regulators, customers and other stakeholders has forced companies to seek for alternatives to achieve green objectives. The difficulties faced by organizations are lack of awareness and guideline in implementing green practices in their daily operation. Under constrained resources, employers are reluctant to spend money on something unclear. During the last decade, lean manufacturing seems to be visible trend in most of the manufacturing industries in Malaysia. As lean tends to emphasize on waste reduction, it provides similarity between lean and green. Therefore, it is a better atmosphere to deploy green practices and tools under existing lean manufacturing. The purpose of this paper is to present a review on the synergies between green and lean and identifying the determinants that affecting both lean and green manufacturing for Malaysian manufacturers. The determinant obtained are financial benefit, incentive, legislation, stakeholder, management commitment, technology, environmental awareness and brand image or competitiveness. Besides, the authors identified and suggested future research directions on developing an integrated lean-green model for daily operation. This study aims to assist researchers to identify the opportunities and challenges on lean-green model and this review is useful for manufacturers and government in developing manufacturing policies and guideline.

  • 112.
    Cortés García, Daniel
    et al.
    University of Skövde, School of Engineering Science.
    Ruiz González, Álvaro
    University of Skövde, School of Engineering Science.
    Laser welding machine specification research2019Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This paper presents the technical specification of a laser welding machine, which main purpose is the weld of thin aluminium sheets. With the application of laser machines in automotive, aerospace, and other industries, it has become of crucial importance for a company working in those fields to keep updated with the technological progress. In this thesis, a deep research in laser machines and its applications has been done. The primary objective of this thesis is to gather knowledge about laser machines to help our client to find the machines they need. Among the several types of machines, the difference in the choice relied on which main type of industrial laser should be used: carbon dioxide (CO2) or neodymium-doped yttrium aluminium garnet (Nd: YAG). The second objective of this thesis is to find the best way to demand those machines to the procurers: to give detailed specifications to the procurers, or to give them just guidelines on what the machine must have and should have. The key results obtained from the research were that laser source to use is the Nd: YAG and that the most appropriate shielding gas is Argon. Therefore, in conclusion, the specifications stated in the table will help our client to acquire the laser machine they demand; as well as spending the money efficiently.

  • 113.
    Cox, Astrid
    University of Skövde, School of Engineering Science.
    Development of Components for a Heat Recycling Shower System2016Independent thesis Basic level (university diploma), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Given the unstable state of the environment, there is an undeniable need for the development of sustainable technologies. This need affects all areas of everyday life, even the shower. Modern shower systems result in energy waste in the form of heat, which can be minimized through the implementation of a heat exchanger.

    In cooperation with Consat SES this project developed a system to implement a heat exchanger using an in-shower water transportation pipe. A fitting non-electrical pump and motor were also chosen.

    To develop these elements a general design methodology of defining the problem, identifying the solution space, developing concepts, testing concepts and proposing a design, was used with adaptations for the component at hand. By following this strategy for each component and then reviewing the system as a whole, a new shower system was developed with a trapezoidal water transport pipe, a wing pump, and a turgo turbine. 

  • 114.
    Cámara Vela, Juan Antonio
    et al.
    University of Skövde, School of Engineering Science.
    Sánchez Molina, Juan Manuel
    University of Skövde, School of Engineering Science.
    Design of a Double Cantilever Beam Test Specimen and Fixture for Kink Band Formation in Unidirectional Fibre Reinforced Composites.2015Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Composite materials are widely used in demanding applications in aerospace and other industries. In order to understand the complex behaviour of the composite materials and their components, standardised test methods are used. One example is the double cantilever beam (DCB) test in which the test specimen is loaded in an opening, i.e., tensile mode. Failures in composite materials loaded compression are different from those in tension, for example, kink band or buckling-like failures can occur.

    In this project, several DCBs are designed and a new fixture which allows for compression testing of a DCB is developed for an existing Instron testing machine. The fixture overcomes a known problem of tensile peak causing the failure of the adhesive at the inner surfaces of the DBC by applying additional compressive loads along the outer surfaces of the DBC. The compressive forces can induce the desired kink band formation so that researchers can better study the failure mode.

    The conceptual development of the new DCBs and the new fixture are presented. Several prototypes of the specimens and the fixture are modelled using the three-dimensional (3D) computer-aided design software Creo Parametric 2.0.  One of the fixtures is selected to further study. The different DCB specimens are studied in order to obtain information about the kink band using 3D finite element analysis with the software programme Abaqus CAE. The selected fixture is analysed to determine if there are any areas of concern. Finally, the behaviour of the compression stress along the DCB using two pairs of forces is studied.

    Unfortunately, it is determined that the tensile peak experienced by the adhesive cannot be eliminated by the application of two pairs of compressive loads, one at the free end and the other in the vicinity of the tensile peak. Several suggestions are made for future work which might serve to reduce the tensile peak; e.g., the movable force couple is applied as a surface load instead of a point load. For this, the fixture will have to be modified with a new geometry, although the DCB could be the same. This will allow further work to focus on the combined behaviour of the tensile peak and the fixture.

  • 115.
    Da Lio, Mauro
    et al.
    Dept. of Industrial Engineering University of Trento, Trento, Italy.
    Mazzalai, Alessandro
    Dept. of Industrial Engineering University of Trento, Trento, Italy.
    Windridge, David
    Dept. of Computer Science Middlesex University, London, United Kingdom.
    Thill, Serge
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre. Centre for Robotics and Neural Systems, University of Plymouth, United Kingdom.
    Svensson, Henrik
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Yueksel, Mehmed
    Robotics Innovation Center - DFKI GmbH German Research Center for Artificial Intelligence Bremen, Germany.
    Gurney, Kevin
    Dept. of Psychology University of Sheffield, Sheffield, United Kingdom.
    Saroldi, Andrea
    Centro Ricerche Fiat S.C.p.A. Orbassano (TO), Italy.
    Andreone, Luisa
    Centro Ricerche Fiat S.C.p.A. Orbassano (TO), Italy.
    Anderson, Sean R.
    Dept. of Automatic Control and Systems Engineering University of Sheffield, Sheffield, United Kingdom.
    Heich, Hermann-Josef
    Consulting – Research – Project Management Heich Consult GmbH, Hürth, Germany.
    Exploiting Dream-Like Simulation Mechanisms to Develop Safer Agents for Automated Driving The "Dreams4Cars" EU Research and Innovation Action2017In: 2017 IEEE 20th International Conference on Intelligent Transportation Systems (ITSC), IEEE, 2017Conference paper (Refereed)
    Abstract [en]

    Automated driving needs unprecedented levels of reliably and safety before marked deployment. The average human driver fatal accident rate is 1 every 100 million miles. Automated vehicles will have to provably best these figures. This paper introduces the notion of dream-like mechanisms as a simulation technology to produce a large number of hypothetical design and test scenarios - especially focusing on variations of more frequent dangerous and near miss events. Grounded in the simulation hypothesis of cognition, we show here some principles for effective simulation mechanisms and an artificial cognitive system architecture that can learn from the simulated situations.

  • 116.
    Dabbagh, Armanj
    et al.
    University of Skövde, School of Technology and Society.
    Garza, Carlos
    University of Skövde, School of Technology and Society.
    Finite Element Analysis of the Vasa’s Bottom Structure2012Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The royal warship Vasa sank on its maiden voyage outside Stockholm and was salvaged more than 300 years later in 1961. Nowadays the vessel lies in its eponymous museum in Stockholm on a dry dock. However, it was determined that the ship cannot handle its own weight in a satisfactory manner with the current support system. Measurements during the past ten years have ascertained that the upper structure components of the hull are slowly deforming, mostly due to creep behavior.

     

    A new support system for the ship needs to be designed in the near future and therefore, the mechanical behavior of its structural members and the stresses they are subjected to have to be determined. Factors that complicate a stress analysis include both inhomogeneity of the oak’s mechanical properties and limited opportunities for experimental testing. Furthermore, contamination, microbial degradation and preservation agents have significantly changed the integrity of the oak.

     

    In this project a section of the Vasa’s bottom structure is studied through Finite Element Analysis in order to determine the stresses and deformations originated by the support system and to have a better understanding of these effects on the ship’s structure. Due to the considerable deterioration of the oak, especially on the external structural members, several assumptions are considered in order to perform analytical calculations to determine appropriate material properties for the FE-Models. 

     

    After performing the computational simulations, the obtained results indicate that the bottom structure exhibits sufficient mechanical integrity to endure the stresses generated by the support system. Even by assuming the possibility of several damaged structural connections, only a minor difference of the effects of the reaction forces on the structure members was determined.

     

    The thesis work ends with further conclusions from the performed analysis and suggested future work.

  • 117.
    Danielsson, Oscar
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Designing Augmented Reality Interfaces for Human-Robot Collaboration in Engine Assembly: Research Proposal2016Report (Other academic)
    Abstract [en]

    Customers are becoming more and more individualistic, products are getting more variation and the global market drives for shorter lifecycles for products. The industry is introducing more robots but even though they become more flexible there is still a need for human workers. Fenceless robots and new standards in robotics have made it possible for humans and robots to directly collaborate, allowing them to complement each other with their respective strengths. But how can humans keep up with the increased need for learning new products while collaborating with robots?Studies in using Augmented Reality (AR) show that it might help workers to perform complex operations more efficiently.AR can spatially orient information and thereby present it in context to reality. But AR in actual industrial assembly is still in its infancy, there is a lack of general AR implementations as most AR is done for specific cases and there is still little knowledge about how to generally design AR-based interfaces efficiently.This project aims to explore how AR is most efficiently used in industrial engine assembly. It focuses on cases with Human-Robot Collaboration since the current trend is clear that this will be very common in the future. The goal is to find basic design guidelines for how to best present information to workers; when to present it, what to present and how to present it.Industry representatives will help in creating an evaluation-framework that is relevant for real situations. The guidelines will be iteratively evaluated with this evaluation-framework and designed through the methodology of design science. The goal of this research project is to contribute with a framework for how to evaluate AR-based operator instructions and design guidelines that creates generally more efficient instructions for operators.

  • 118.
    Danielsson, Oscar
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Terminator technology - this is how it can help the manufacturing industry: The University of Skövde conducting research regarding AR as a form of support for operators2015In: The Vehicle Component, ISSN 1652-862X, no 4, p. 35-36Article in journal (Other (popular science, discussion, etc.))
  • 119.
    Danielsson, Thomas
    University of Skövde, School of Engineering Science. tomasdanielsson@hotmail.com.
    Förslag på flexibel och balanserad monteringslinje: Manuellt monteringsflöde för säsongsberoende efterfrågan2017Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Volvo GTO Powertrain is facing the introduction of three new product types of products which shall replace existing product types. In the current situation are the products, which shall be replace by new product types, assembled in three separate flows. The introduction of the new product types includes that two product types are being assembled in the same assembly flow. The purpose of this report is to make suggestions on assembly flows that have the flexibility to produces two of the new product types in the same assembly flow with associated trial area. The assembly flow shall also accomplish the customer’s demand depending on season with 23 - 40 products per shift, with a difference of ± 2,5 %. To adjust the quantity that shall be produced depending on season shall be done by adjusting the quantity of fitters in the assembly flow and the quantity of operators in the trial area.

    To create an understanding of the existing assembly flows has an analysis of the present situation, of the assembly flows which shall be combined into one assembly flow, been completed. The data collection in the analysis of the present situation has been completed through interviews with production engineers staff, also by studying the AviX analysis concerning the existing assembly flows. The analysis of the present situation has been founded to create an understanding of how the assembly works today.

    Furthermore, Volvo has developed a proposal on how the future assembly flow shall look like. Volvo’s proposal has been founded to create an understanding of the future assembly flow with associated trial area.

    To achieve the purpose of this work has two simulation models been created to test the system under different scenarios to manage the varying demand. One of the simulation models is using Volvo’s proposal on the future system and the other model has adjusted cycle times in the trial area through experiments, the work pace in the assembly flow has been rebalanced and the OEE in the trial run has been increased.

    The results from the experiments are that the simulation model with adjusted cycle times, rebalanced and increased OEE is capable of coping with the varying demand on 23 – 40 products per shift. However, relatively large adjustments were required from Volvo’s proposal to achieve the desired demand. A table of staffing was created to determine how many fitters and operators were required depending on the quantity of demanded products.

  • 120.
    Deb, Kalyanmoy
    et al.
    Michigan State University.
    Bandaru, Sunith
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Engineering Science.
    Greiner, David
    Universidad de Las Palmas de Gran Canaria.
    Gaspar-Cunha, António
    University of Minho, Campus de Azurém.
    Tutum, Cem Celal
    Michigan State University.
    An integrated approach to automated innovization for discovering useful design principles: Case studies from engineering2014In: Applied Soft Computing, ISSN 1568-4946, E-ISSN 1872-9681, Vol. 15, no 2, p. 42-56Article in journal (Refereed)
    Abstract [en]

    Computational optimization methods are most often used to find a single or multiple optimal or near-optimal solutions to the underlying optimization problem describing the problem at hand. In this paper, we elevate the use of optimization to a higher level in arriving at useful problem knowledge associated with the optimal or near-optimal solutions to a problem. In the proposed innovization process, first a set of trade-off optimal or near-optimal solutions are found using an evolutionary algorithm. Thereafter, the trade-off solutions are analyzed to decipher useful relationships among problem entities automatically so as to provide a better understanding of the problem to a designer or a practitioner. We provide an integrated algorithm for the innovization process and demonstrate the usefulness of the procedure to three real-world engineering design problems. New and innovative design principles obtained in each case should clearly motivate engineers and practitioners for its further application to more complex problems and its further development as a more efficient data analysis procedure.

  • 121.
    Delfs, Niclas
    et al.
    Fraunhofer-Chalmers Research Centre, Gothenburg, Sweden.
    Bohlin, Robert
    Fraunhofer-Chalmers Research Centre, Gothenburg, Sweden.
    Hanson, Lars
    Industrial Development, Scania CV, Södertälje, Sweden.
    Högberg, Dan
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Carlson, Johan S.
    Fraunhofer-Chalmers Research Centre, Gothenburg, Sweden.
    Introducing Stability of Forces to the Automatic Creation of Digital Human Postures2013Conference paper (Refereed)
    Abstract [en]

    Although the degree of automation is increasing in manufacturing industries, many assembly operations are performed manually. To avoid injuries and to reach sustainable production of high quality, comfortable environments for the operators are vital. Poor station layouts, poor product designs or badly chosen assembly sequences are common sources leading to unfavorable poses and motions. To keep costs low, preventive actions should be taken early in a project, raising the need for feasibility and ergonomics studies in virtual environments long before physical prototypes are available. Today, in the automotive industries, such studies are conducted to some extent. The full potential, however, is far from reached due to limited software support in terms of capability for realistic pose prediction, motion generation and collision avoidance. As a consequence, ergonomics studies are time consuming and are mostly done for static poses, not for full assembly motions. Furthermore, these ergonomic studies, even though performed by a small group of highly specialized simulation engineers, show low reproducibility within the group.Effective simulation of manual assembly operations considering ergonomic load and clearance demands requires detailed modeling of human body kinematics and motions as well as a fast and robust inverse kinematics solver. In this paper we introduce a stability measure rewarding poses insensitive to variations in contact points and contact forces. Normally this has been neglected and only the balance of moment and forces has been taken into account. The manikin used in this work has 162 degrees of freedom and uses an exterior root. To describe operations and facilitate motion generation, the manikin is equipped with coordinate frames attached to end-effectors like hands and feet. The inverse kinematic problem is to find joint values such that the position and orientation of hands and feet matches certain target frames during an assembly motion. This inverse problem leads to an underdetermined system of equations since the number of joints exceeds the end-effectors’ constraints. Due to this redundancy there exist a set of solutions, allowing us to pick a solution that maximizes a scalar valued comfort function. Many objectives are included in the comfort function, for example in terms of joint angles, joint moments and solid objects’ distance to the manikin. The proposed stability measure complements the earlier balance criterion and is combined into the comfort function. By increasing the importance of this function the digital human model will reposition to a more stable pose. The digital human model will be tested on a set of challenging assembly operations taken from the automotive industry to show the effect of the stability measure.

  • 122.
    Dhanal, Avirat
    University of Skövde, School of Engineering Science.
    Design and Analysis of Material Handling System with Simulation-Based Optimization2018Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    In today’s world, simulation and optimization are playing a vital role in reducing the time, cost and preserving resources. In manufacturing industries, there are ample amount of problems that go on with the expansion of the industry. In such cases, to tackle these problems simulation can be helpful to check whether any change in the current situation makes any effect on the current efficiency of the overall plant. In the presented case study, a solution to the problem of internal and external logistics has been designed by using simulation and optimization to improve part of a material flow of an organization. Basically, the organization whose major production is established in the south of Sweden deals with the manufacturing and assembly of equipment. Before the dispatch, all of them go to the painting section which is the expansion of the present shop floor. However, the design and analysis of the material handling system to feed the new painting line which is going to be established by the organization is the aim of this case study. While achieving this aim the literature regarding the discrete event simulation, Lean and Simulation-Based optimization related to the material handling system has been done. Furthermore, the appropriate material handling systems along with the different scenarios were suggested to reduce the cost and the lead times between the production line and the new painting line. To support this process a methodology combining simulation, optimization and lean production has been implemented under the framework of the design and creation research strategy. In the Kaizen workshop organized at a company with managers and stakeholders, the designed scenarios were presented and after some discussion one of them was chosen and the selected scenario was designed and optimized. Moreover, the Simulation-Based multi-objective optimization has been helpful for the optimization of the designed model proposed as a final solution.

  • 123.
    Dubinovic, Nermin
    et al.
    University of Skövde, School of Engineering Science.
    Nelson, Denny
    University of Skövde, School of Engineering Science.
    HUR CIRKULÄR EKONOMI KAN IMPLEMENTERAS I SMÅ OCH MEDELSTORA FÖRETAGS PRODUKTUTVECKLING2015Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Today’s trend of production and consumption has a linear type. Material is extracted, become products and then end up as landfill. This thesis has together with Industrial Development Center AB aimed to create a more sustainable industrial production within the region of Skaraborg, by forming a product development process according to circular economy. Circular economy advocates that there should be no waste and products and material should circulate throughout different cycles. Hence this thesis consist of a broad pre-study to collect and evaluate a big range of theories, processes and enterprise responsibilities. Later on a general product lifecycle was studied and a map of a process was made with circular economy and product development processes in mind. The work was tied together by a performance specification table. This document was also used as a basis for the evaluation of the final product development process with circular economy implemented. Finally, the result was also evaluated by an experienced user to get an initial assessment of the result’s usability for the target groups. The result was an environmentally adapted product development process and a folder explaining how and why circular economy is to support enterprises and the community.

  • 124.
    Dudas, Catarina
    et al.
    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.
    Pehrsson, Leif
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Boström, Henrik
    Department of Computer and Systems Sciences, Stockholm University, Stockholm, Sweden.
    Integration of data mining and multi-objective optimisation for decision support in production system development2014In: International journal of computer integrated manufacturing (Print), ISSN 0951-192X, E-ISSN 1362-3052, Vol. 27, no 9, p. 824-839Article in journal (Refereed)
    Abstract [en]

    Multi-objective optimisation (MOO) is a powerful approach for generating a set of optimal trade-off (Pareto) design alternatives that the decision-maker can evaluate and then choose the most-suitable configuration, based on some high-level strategic information. Nevertheless, in practice, choosing among a large number of solutions on the Pareto front is often a daunting task, if proper analysis and visualisation techniques are not applied. Recent research advancements have shown the advantages of using data mining techniques to automate the post-optimality analysis of Pareto-optimal solutions for engineering design problems. Nonetheless, it is argued that the existing approaches are inadequate for generating high-quality results, when the set of the Pareto solutions is relatively small and the solutions close to the Pareto front have almost the same attributes as the Pareto-optimal solutions, of which both are commonly found in many real-world system problems. The aim of this paper is therefore to propose a distance-based data mining approach for the solution sets generated from simulation-based optimisation, in order to address these issues. Such an integrated data mining and MOO procedure is illustrated with the results of an industrial cost optimisation case study. Particular emphasis is paid to showing how the proposed procedure can be used to assist decision-makers in analysing and visualising the attributes of the design alternatives in different regions of the objective space, so that informed decisions can be made in production systems development.

  • 125.
    Edvardsson, Felicia
    et al.
    University of Skövde, School of Engineering Science.
    Warberg, Therése
    University of Skövde, School of Engineering Science.
    Konceptuell utveckling av interiören hos en framtida fullt autonom bil2016Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The goal with this thesis project has been to collect information for a technical consulting company in order to increase their knowledge about autonomous systems and vehicular communication. The status of how various operators work with active safety systems and how the systems are implemented in current and future vehicles has been investigated through extensive literature studies, interviews and market research. The autonomous systems can collect information from the surrounding through sensors and contribute to better traffic efficiency, increased safety, lighter cars and a better environment. Through vehicle communication, the vehicle can communicate with each other in order to guarantee a safe ride. In 2030 the inner city constitutes of autonomous, electrified public transport to transport people on demand, meanwhile private cars are prohibited. Potential needs for the human in a fully, autonomous car has been identified and various product development methods has been applied in order to develop two conceptual solutions for a future car interior. The solutions show the interaction between human and system since entertainment and comfort becomes important in a fully, autonomous car. Each solution is state-owned and holds four passengers. In the solutions, the seats are placed in regard to facilitate communication between the passengers. The passengers can be entertained or informed individually or collectively by text, sound and images.

  • 126.
    Eklind, Alexander
    et al.
    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.
    Carlberger, Thomas
    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.
    High cycle fatigue crack growth in Mode I of adhesive layers: modelling, simulation and experiments2014In: International Journal of Fracture, ISSN 0376-9429, E-ISSN 1573-2673, Vol. 190, no 1-2, p. 125-146Article in journal (Refereed)
    Abstract [en]

    The capability to predict high cycle fatigue properties of adhesive joints is important for cost-efficient and rapid product development in the modern automotive industry. Here, the adaptability of adhesives facilitates green technology through the widening of options of choosing and joining optimal materials. In the present paper a continuum damage mechanics model is developed based on the adhesive layer theory. In this theory, through-thickness averaged variables for the adhesive layer are used to characterise the deformation, damage and local loading on the adhesive layer. In FE-simulations, cohesive elements can thereby be used to model the adhesive layer. This simplifies simulations of large scale complex built-up structures. The model is adapted to experimental results for two very different adhesive systems; one relatively stiff rubber based adhesive and one soft polyurethane based adhesive. The model is able to reproduce the experimental results with good accuracy except for the early stage of crack propagation when the loads are relatively large. The model also predicts a threshold value for fatigue crack growth below which no crack growth occurs. The properties of the model are also compared with the properties of Paris’ law. The relations between the parameters of the continuum damage mechanics law and the parameters of Paris’ law are used to adapt the new law. It also shows that the properties of a joined structure influence the Paris’ law properties of the adhesive layer. Thus, the Paris’ law properties of an adhesive layer are not expected to be transferable to joints with adherends having different mechanical properties.

  • 127.
    Eklind, Samuel
    University of Skövde, School of Technology and Society.
    Utveckling av gåbord2007Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
  • 128.
    Eklind, Sebastian
    et al.
    University of Skövde, School of Engineering Science.
    Larsson, Michelle
    University of Skövde, School of Engineering Science.
    Samarbetet mellan människa och automation i det avhjälpande underhållet: behovsanalys och krav på framtida utveckling av automationsutrustning2017Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The project has explored the interaction between humans and automation within the remedial maintenance on two manufacturing companies. The purpose of the project is to contribute to the interaction between humans and automation and by that make it successful in the future. The study has investigated how the present interaction is designed, where there is a need for interaction, how the interaction can be designed in the future together with the requirements that will need to be achieved to get there. In this study there is also a focus on sustainable development and how the interaction affects it. The result of the project is produced by performing two attendance observations, one at each company and four semi-structured interviews at each company. Today a lot of communication is done by phone to get the attention of personnel and summon them to the machine that has stopped. The troubleshooting of the machine is done in a panel or with a computer if deeper troubleshooting is needed. The computer needs to be connected to the machine. Today there are some technics that are present but these are not used due to the fact that they are perceived tedious to use. These technics are communication radio, mouse and keyboard. The result of the study indicates that there is a need for more information in all the phases of a remedial maintenance work. It also shows that the technics needs to be more mobile compared to how it is today. The authors recommends that handheld devices are used in the future and that softwares such as voice recognition, Virtual Reality and Augmented Reality are used within the handheld devices. Smartwatches are also interesting in an attention point of view where alarm messages can be shown. There is a belief that with more information and more mobility the maintenance will be more effective in the future and that the time for remedial maintenance will reduce. The authors strongly recommend that all technics that will be implemented need to first be tested in a realistic environment and by the people that should use it.

  • 129.
    Eliasson, Fredrik
    et al.
    University of Skövde, School of Engineering Science.
    Todorovic, Ilija
    University of Skövde, School of Engineering Science.
    Deformationsanalys av klämvillkor av en vevaxel2017Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Crankshaft deformation is studied in connection with clamping conditions in a whirl milling machine before a cutting process. The purpose of the project is to increase knowledge about the deformation behaviour of the crankshaft and its important functional surfaces by performing analyses using the finite element method (FEM). Volvo Cars in Skövde, Sweden is currently managing unwanted crankshaft deformation occurrence by using time consuming physical testing methods. Therefore, the company wish to use virtual analyses instead of physical tests. This work also leads to a determination if FEM is an applicable tool in order to maintain narrow tolerances of the crankshaft. Using virtual analyses instead of physical tests would be time saving and would also have a positive impact on the environment.

    The computer software Abaqus is used to implement the deformation analyses that are also evaluated against physical measurements done with a tensile testing machine (Instron) and thereby be able to ensure the reliability of the used FE model. FE analyses are mainly performed to evaluate the deformation of the crankshaft associated with clamping. Two different crankshaft types are being analysed. A FE model is created for each crankshaft along with applied boundary and load conditions according to performed mechanical analysis of the crankshaft.

    Obtained results show that the thrust bearing sides of the crank pins on the crankshaft deform in the range of  mm when the crankshaft is compressed during clamping with 0.2 mm. This deformation is considered to entail a risk for a processing error to occur. At the same time the analyses show which surfaces are most/least deformed. Evaluation according to the tensile testing indicates that the direction of the crankshaft deformation corresponds to the analysis but slight deviation of the deformation magnitude is present. The deviations can be explained by variations of the E-module within the crankshaft while the defined E-module in Abaqus has a constant value. Furthermore, there is a possibility that sources of error from the tensile tests can have an influence on the obtained results from the physical measurements.

    Conducted analyses indicates that FEM is applicable for crankshaft deformation analyses and recommendations of a suitable FE model are provided. A potential solution of the deformation problem is considered to be the calculation of optimal clamping force.

  • 130.
    Elofsson, David
    University of Skövde, School of Technology and Society.
    Konceptuell design för elverk drivet av kroppsenergi: Avsett för bruk i en fältmässig miljö2011Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    A conceptual design for a generating set, driven by muscle power and intended for use in a field-rateenvironment, has been developed at the request of the rehabilitation-center of Vätterbygden and Universityof Skövde. A concept has been generated and chosen, and dimensioning calculations and choice ofmaterials for vital parts has been performed, partly using the CAD-software Pro/Engineer Wildfire 5.0and its application Mechanica Structure. Other tools used in the process include identification of customerneeds, generation of target specifications, Black box, Morphological tables, Pugh’s matrix for choiceof concepts and weighted matrix for choice of concepts.The generating set's purpose is to be used in emergency relief activities when the local power grid isdown and there are no fossil fuels at hand. In such situations the generating set may be seen as a powerfulcompliment to solar and wind power, since it makes the power supply independent of wind and solarconditions.The operating principle of the generating set is partly that of a rowing ergometer. The user applies analternating pull, belted to a mobile seat and holding a handle-bar. The users return to start position iseased by a spiral spring. This motion is repeated about 25 times each minute. A steel wire rope runs fromthe handle to a reel which in turn is mounted on a driveshaft. The driveshaft is through a free-wheel connectedto a planetary gearbox, shifting the average rotational speed from 60 rotations per minute to1500. A flywheel decreases the variation in rotational speed, before a synchronous generator with fourpoles is driven by the remaining torque. The frequency of the generated power is lastly adjusted to 50 Hzusing a frequency converter.According to the 1995 J. Carlstedt book "Tester för idrottare", the lactic acid threshold limits the workloada person can endure without rapid fatigue. This limit is exceeded when the oxygen absorption of theindividual hits 70-90 % of capacity (VO2max), depending on the level of fitness. The study ”Stroke PowerConsistency and 2000 m rowing performance in varsity rowers”, conducted by Shimoda et al. in 2007,concludes that varsity rowers can achieve a maximum oxygen absorption of VO2max = 4,1 ± 0,4 l/min at arowing workload of 300 Watts. Based on the workload in this study corresponding to 70 % of VO2maxbeing 200 Watts, this magnitude of power was judged as the endurable workload a user of the generatingset could be expected to supply.The required diameter of the steel wire rope and dimensions for the wire reel has been settled. The appropriatenumber of teeth for the planetary gearbox’s cog-wheels has been calculated, as well as themoment of inertia for the flywheel. A specific self-aligning ball-bearing with an adapter sleeve, SKF 1206EKTN9, has been chosen for use at the driveshaft of the generating set. Furthermore, materials and dimensionshave been determined for the wire reel, the flywheel, footrests, load-bearing structure and partsof the seat through the use of analyses in Mechanica Structure. Lastly, two images showing the functionand parts of the generating set have been rendered.With a degree of efficiency when operating at a 200 W workload of η = 0.86 for the generator and η =0.94 for the planetary gearbox, 160 W remains before any currently unknown frictional losses has beensubtracted. Hence, this generating set is unable to compete with generating sets driven by diesel andgasoline in regard of capacity. The main advantage of the generating set is instead the ability to generatepower regardless of time of day, weather-conditions or fuel-access, as long as there’s an individualavailable for powering it.The development of the generating set is still very much a work in progress. It is recommended that theidentified customer needs and set target specifications are continuously regarded during possible proceededdevelopment.

  • 131.
    Emnerud, Tobias
    et al.
    University of Skövde, School of Technology and Society.
    Svensson, Katarina
    University of Skövde, School of Technology and Society.
    Energy Optimization of Hydraulic Systems: An investigation of energy-efficient designs for hydraulic systems2011Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    An investigation of the global energy consumption debate confirms the complexity of the global environmental issues, the severity of the impact in developing countries and the major efforts that is required to discourse this development. Electricity production is the largest growing source of CO2- emissions, mainly due to the expansion of coal power plants in China and India. Therefore one can easily argue for the importance of develop more environmentally friendly use of coal. However, the cheapest measure to reduce CO2-emissions is not to develop new technologies but to use the produced energy more effective, regardless of energy source.  In this final thesis in mechanical engineering investigates the possibilities of modifying two hydraulic systems in an energy efficiency perspective. The investigations will show if there is potential for implementing energy-saving investments in hydraulic systems.

    Two hydraulic units that are representative for the hydraulics at Sandvik Materials Technology were chosen. One unit controls a hydraulic system that moves steel bars through an oven, and the other unit drives machines that straighten crooked tubes. Pressure-measurements and calculated flow demands showed that both systems had potential for energy efficiency work. By the use of accumulators four different concepts have been developed. With an investment analysis as a basis, one concept per system has been considered profitable. 

    For the system referred to as the tube-straightener a concept that uses two pumps and motors of two different sizes has been considered profitable. The thought is to let the smaller pump and motor take the base-load of 2 kW that is used when the motor is idle-running. A timer shuts the machine after 25 seconds, which is where the profitability of the concept is found. Hence, large energy consumption savings can be achieved just by changing the time set on the timer. With the modifications that are represented in this thesis, the energy consumption is decreased by 45 %.The potential for energy efficiency work is thereby confirmed. However, the analyzed systems are too small to generate a short pay-back time. If similar modifications are performed on larger units, the pay-back time will drop dramatically. 

    In the most economic viable concept for the hydraulic system referred to as the oven, one of the existing three pumps is removed. The two remaining pumps control two different flow different demands. One pump manages the flow demand of one cylinder with a high demand. The other pump manages the remaining flow demand with the help of installed accumulators. The motors are replaced since the current motors are oversized. This investment has a payback period of 2.7 years and will reduce the energy consumption by 25% which corresponds to approximately SEK 25 000.

    Furthermore, the eyes are lifted from the specific systems that have been subjected to this analysis and underlying factors of over dimensioned hydraulic systems in today´s industries are brought up. Incentives that affect the constructor’s decisions play an important part in the underlying factors that is presented. As long as the constructor is punished to a greater extent for undersized systems than he or she is rewarded for designing smaller, more energy efficient systems, this problem will remain. Another aspect that is brought up is the time limit, when the time limit is set very short the risk of losing precision in estimation of needed system capacity increases.

  • 132.
    Engman, Arvid
    et al.
    University of Skövde, School of Technology and Society.
    Johansson, Carljohan
    University of Skövde, School of Technology and Society.
    Hållfasthetsanalys av infästningmellan AGV och motor: med hänsyn till femfaldig säkerhet mot brott2012Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Automated Guided Vehicles, AGV´s, are mainly used as a mounting platform in the heavy vehicle industry. An AGV is commonly used in the assembly process of; engines, gearboxes and chassis. The AGV transports the product through a predefined trail in the plant where the product is mounted.

    Today the AGV is being sold with a promise, from the manufacturer, that the construction is engineered with a safety factor five, against fracture, for any component in the AGV. It is engineered to support loads to a maximum of 1800 kg, with this safety factor included. The center of gravity is allowed to be one meter out from the mount that connects AGV with the supported load.

    This work investigates if the coupling, which connects the supported engine with the AGV, meets safety requirements. The coupling consists three main parts; fixture, cam-disk and an adapter plate. The fixture and cam-disk is mounted on the AGV, and the adapter plate is tem-porarily mounted on the engine. The adapter plate has three so called “heels” that links it with the fixture.

    To determine how well the coupling meets the safety requirements, the forces acting in the structure, while the AGV is loaded, is calculated. The work load is illustrated by a fictional engine, weighing 1800 kg with its center of gravity placed one meter out from the mount. These forces form the basis for the FE-analyzes, investigating the coupling strength proper-ties. Knowing the couplings strength properties, conclusions if the coupling meets the safety requirements can be adopted.

    The coupling component has, in general, good strength properties that meet the safety re-quirement of five-times security. The results show that some components have tenfold safety, while the AGV carries a load of 1800 kg. Calculations show that the screw connections of the fixture don’t meet the safety requirement and needs to be further investigated.

    The pilot study revealed that the fixture, for some AGVs, has been assembled with wrong screws. Instead of 10.9-screws, 8.8-screws were used. This leads to a serious consequence of reduced security for the construction. The cause of why fault screw was used is not known. One approach to prevent wrong screw is highlighted as suggestions for improvement.

    To understand why such a high security factor as five is chosen, the regulations “AFS 2008:3 – maskiner” that formed the basis for selecting the safety factor is studied. The study has been a basis for the conclusions for this work.

    The results of this survey may serve as a basis for further work, when further development of the coupling is relevant.

  • 133.
    Enoksson, Frida
    University of Skövde, School of Engineering Science.
    Implementering av ekodesignmetoder i Nobias befintliga designprocess2017Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The bachelor project has been carried out at the University of Skövde in collaboration with Nobia AB. The purpose of the project was to implement eco-design methods into the company’s existing design process and to accomplish a case study of a cabinet door. The purpose of the case study was to verify the proposed eco-design process and suggest a material for a cabinet door.

    Sustainable development, eco-design and lifecycle were studied during the literature study. Interviews were carried out to study the design process at Nobia and to identify the different activities in every phase of the process. The phases were Idea Generation, Concept Development, Product Development and Industrialization. Several eco-design methods were studied to assess their potential to be implemented into Nobia’s existing design process, for example Status Analysis and various Checklists. The expected characteristics of the eco-design process were compiled into a requirement specification.

    The methods which were implemented into Nobia’s existing design process resulted in an Eco-design process which consisted of Ekostrategihjul, Philips five fast, Jämförelsematris, Eco-design portfolio, Environmental Failure Mode and Effect Analysis and Scorecard. The case study was initiated by compiling a requirement specification. The most promising materials were Medium Density Fibreboard, bamboo and fir. Through analysis of various materials fir was considered as the best material because of low levels of pollution during transportation, good access to the raw material and it is also locally manufactured.

    The results show that the use of eco-design within product development entails many advantages, such as, a pleasant place of work, motivated staff, and a more sustainable design process. A sustainable design process will contribute to the development of sustainable products, which entails a better environment.

  • 134.
    Erlandsson, Elisabeth
    et al.
    University of Skövde, School of Technology and Society.
    Wångdahl, Madeleine
    University of Skövde, School of Technology and Society.
    Utveckling av dörrinredning till premiumkylskåp2013Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This degree project is performed in collaboration with AB Electrolux Mariestad factory that works with product development and manufacturing of refrigerators and freezers. The task was to develop an overall concept of the inside of a refrigerator door in the premium segment with focus on attachment and modularization of balconies. The refrigerator that the overall concept will be placed in has an interior of stainless steel, which means that the solutions that are currently practiced for the refrigerator door cannot be used.

    The project began with an investigation of the background for the task and a pilot study where the target group was defined, the competitors were identified and requirements from the users were collected. This was followed by a thorough concept development phase, which included generation of ideas, creation of concepts, concept selection and development of details.

    The final overall concept was visualized with a prototype, which offers continuous adjustment of balconies on the refrigerator door.  The basic construction consists of two extruded aluminium profiles, which have a concealed attachment on the door. On the profiles consoles are placed, on which the balconies are then assembled. The consoles serve as sidepieces for the balconies and hide a locking mechanism that fixates the balconies vertically by means of friction.

    The overall concept that has been developed fulfils the requirements that initially were set up for the product, however additional further development remains for the overall concept to be brought into production. 

  • 135.
    Farkish, Farhad
    et al.
    University of Skövde, School of Engineering Science.
    Othman, Haval
    University of Skövde, School of Engineering Science.
    Analys av lagerhaveri2017Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The short lifespan of a bearing is analyzed in a carousel wheel at Skara Sommarland. The aim of this report is to find the cause of failure for the bearing. The machine that is to be analyzed is mounted on the ground between the rails. Unpredictable breakdowns for the machine causes high expenses, as maintenance has to be carried out and the carousel has to be shut down, which makes it unable to generate revenue from customers. A number of bearings was analyzed using a microscope. The purpose of this analysis was to identify, categorize and compare the microscope pictures with SKF’s reference pictures. Results from the analysis show that the unsuitable loads have very little effect on bearing failure. Results from the microscope analysis shows clear images of damage in the bearing. Traces of scratches and indentations on the inside indicates that dust and particles have contaminated the bearing. The pictures also show rust on the inside of the bearing. To avoid or minimize the problem of short bearing life, some improvements are suggested. One suggestion is to make some sort of cover to lower or prevent moisture and water from entering the bearing. Two concepts for the cover were developed for suggestions on how these bearing covers might look like. The concepts were mainly developed to keep water out of the bearing. To ensure that contaminations are the biggest cause of bearing failure, more microscope analyses of the bearings should be performed in the future.

  • 136.
    Fast-Berglund, Åsa
    et al.
    Chalmers University of Technology, Gothenburg, Sweden.
    Thorvald, Peter
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Billing, Erik
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Palmquist, Adam
    Insert Coin, Gothenburg, Sweden.
    Romero, David
    Tecnologico de Monterrey, Mexico.
    Weichhart, Georg
    Profactor, Studgart, Austria.
    Conceptualizing Embodied Automation to Increase Transfer of Tacit knowledge in the Learning Factory2018In: "Theory, Research and Innovation in Applications": 9th International Conference on Intelligent Systems 2018 (IS’18) / [ed] Ricardo Jardim-Gonçalves, João Pedro Mendonça, Vladimir Jotsov, Maria Marques, João Martins, Robert Bierwolf, IEEE, 2018, p. 358-364, article id 8710482Conference paper (Refereed)
    Abstract [en]

    This paper will discuss how cooperative agent-based systems, deployed with social skills and embodied automation features, can be used to interact with the operators in order to facilitate sharing of tacit knowledge and its later conversion into explicit knowledge. The proposal is to combine social software robots (softbots) with industrial collaborative robots (co-bots) to create a digital apprentice for experienced operators in human- robot collaboration workstations. This is to address the problem within industry that experienced operators have difficulties in explaining how they perform their tasks and later, how to turn this procedural knowledge (knowhow) into instructions to be shared among other operators. By using social softbots and co-bots, as cooperative agents with embodied automation features, we think we can facilitate the ‘externalization’ of procedural knowledge in human-robot interaction(s). This enabled by the capabilities of social cooperative agents with embodied automation features of continuously learning by looking over the shoulder of the operators, and documenting and collaborating with them in a non-intrusive way as they perform their daily tasks. 

  • 137.
    Fathi, Masood
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Fontes, Dalila Benedita Machado Martins
    University of Porto, Portugal / INESC TEC, Porto, Portugal.
    Urenda Moris, Matias
    Jönköping University, Jönköping, Sweden / Uppsala University, Sweden.
    Ghobakhloo, Morteza
    University of Hormozgan, Bandar Abbas, Iran.
    Assembly line balancing problem: a comparative evaluation of heuristics and a computational assessment of objectives2018In: Journal of Modelling in Management, ISSN 1746-5664, E-ISSN 1746-5672, Vol. 13, no 2, p. 455-474Article in journal (Refereed)
    Abstract [en]

    Purpose – The purpose of this study is to firstly investigate the efficiency of the most commonly used performance measures for minimizing the Number of Workstations (NWs) in approaches addressing Simple Assembly Line Balancing Problem (SALBP) for both straight and U-shaped line. Secondly, this study aims to provide a comparative evaluation of 20 constructive heuristics to find solutions to the SALBP-1.

    Design/methodology/approach – 200 problems are solved by 20 different constructive heuristics for both straight and U-shaped assembly line. Moreover, several comparisons have been made to evaluate the performance of constructive heuristics.

    Findings – Minimizing the Smoothness Index (SI) is not necessarily equivalent to minimizing the NWs, therefore, it should not be used as the fitness function in approaches addressing the SALBP-1. Line efficiency (LE) and the idle time (IT) are indeed reliable performance measures for minimizing the NWs. The most promising heuristics for straight and U-shaped line configurations for SALBP-1 are also ranked and introduced.

    Practical implications – Results are expected to help scholars and industrial practitioners to better design effective solution methods for having a most balance assembly line. This study will further help with choosing the most proper heuristic with regard to the problem specifications and line configuration.

    Originality/value – There is limited research assessing the efficiency of the common objectives for SALBP-1. This study is among the first to prove that minimizing the workload smoothness is not equivalent to minimizing the NWs in SALBP-1 studies. This work is also one of the first attempts for evaluating the constructive heuristics for both straight and U-shaped line configurations.

  • 138.
    Fathi, Masood
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Nourmohammadi, Amir
    Department of Industrial & Systems Engineering, Tarbiat Modares University, Tehran, Iran.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Assembly Line Balancing Type-E with Technological Requirement: A Mathematical 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. 183-188Conference paper (Refereed)
    Abstract [en]

    This study is motivated by a real-world assembly line in an automotive manufacturing company and it addresses the simple assembly line balancing problem type-E (SALBPE). The SALBPE aims to maximize the balance efficiency (BE) through determining the best combinations of cycle time and station number. To cope with the problem, a mixed integer nonlinear programming (MINLP) model is proposed. The MINLP model differs from the existing ALBPE models as it includes the technological requirements of assembly tasks and optimizes the variation of workload beside the BE. The validity of the proposed model is tested by solving the real-world case study and a set of benchmark problems.

  • 139.
    Fathi, Masood
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Nourmohammadi, Amir
    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.
    Syberfeldt, Anna
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    An optimization model for balancing assembly lines with stochastic task times and zoning constraints2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 32537-32550, article id 8663269Article in journal (Refereed)
    Abstract [en]

    This study aims to bridge the gap between theory and practice by addressing a real-world assembly line balancing problem (ALBP) where task times are stochastic and there are zoning constraints in addition to the commonly known ALBP constraints. A mixed integer programming (MIP) model is proposed for each of the straight and U-shaped assembly line configurations. The primary objective in both cases is to minimize the number of stations; minimizing the maximum of stations’ mean time and the stations’ time variance are considered secondary objectives. Four different scenarios are discussed for each model, with differences in the objective function. The models are validated by solving a real case taken from an automobile manufacturing company and some standard test problems available in the literature. The results indicate that both models are able to provide optimum solutions for problems of different sizes. The technique for order preference by similarity to ideal solution (TOPSIS) is used to create reliable comparisons of the different scenarios and valid analysis of the results. Finally, some insights regarding the selection of straight and U-shaped layouts are provided.

  • 140.
    Fathi, Masood
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Nourmohammadi, Amir
    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.
    Syberfeldt, Anna
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Eskandari, Hamidreza
    Faculty of Management and Economics, Tarbiat Modares University, Tehran, Iran.
    An improved genetic algorithm with variable neighborhood search to solve the assembly line balancing problem2019In: Engineering computations, ISSN 0264-4401, E-ISSN 1758-7077Article in journal (Refereed)
    Abstract [en]
    • Purpose – This study aims to propose an efficient optimization algorithm to solve the assembly line balancing problem (ALBP). The ALBP arises in high-volume, lean production systems when decision makers aim to design an efficient assembly line while satisfying a set of constraints.
    • Design/methodology/approach – An improved genetic algorithm (IGA) is proposed in this study to deal with ALBP in order to optimize the number of stations and the workload smoothness.
    • Findings – To evaluate the performance of the IGA, it is used to solve a set of well-known benchmark problems and a real-life problem faced by an automobile manufacturer. The solutions obtained are compared against two existing algorithms in the literature and the basic genetic algorithm. The comparisons show the high efficiency and effectiveness of the IGA in dealing with ALBPs.
    • Originality/value – The proposed IGA benefits from a novel generation transfer mechanism that improves the diversification capability of the algorithm by allowing population transfer between different generations. In addition, an effective variable neighborhood search is employed in the IGA to enhance its local search capability.
  • 141.
    Fathi, Masood
    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.
    Ghobakhloo, Morteza
    University of Hormozgan, Bandar Abbas, Iran.
    Eskandari, Hamidreza
    Tarbiat Modares University, Tehran, Iran.
    An optimization model for material supply scheduling at mixed-model assembly lines2018In: Procedia CIRP, ISSN 2212-8271, E-ISSN 2212-8271, Vol. 72, p. 6p. 1258-1263Article in journal (Refereed)
    Abstract [en]

    This study is motivated by a real case study and addresses the material supply problem at assembly lines. The aim of the study is to optimally schedule the delivery of raw material at assembly lines while using the minimum number of vehicles. To cope with the problem an original mixed integer linear programming model has been proposed based on the assumptions and constraints observed in the case study. The validity of the model has been examined by solving several real cases and analysing different scenarios. The results of the study show the efficiency and effectiveness of the model.

  • 142.
    Flebus, Philip-Jan
    et al.
    University of Skövde, School of Technology and Society.
    Ferriz Bosque, Silvia
    University of Skövde, School of Technology and Society.
    Development and design of a kitchen solution using Inclusive and Pleasure Design.2012Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The largest age group in western society, the baby boomers, was born between 1943 and 1964, considering different definitions for the time span. All these people have an age between 62 and 48 years old. The life expectancy of these people is the highest in history and they will be more and more willing to stay independent as long as possible. The core of independence is being able to provide and take care of oneself. In order to do that, the instruments that surround the person have to be adjusted to the needs of the person and aid as much as possible.

    This is the report of a Bachelor Degree Project that has the intention to develop a kitchen accessible for all people, both people with full ability and people with limited capabilities, using the inclusive design toolkit. At the same time it has to be appealing enough that people without limited capabilities also enjoy the use of this kitchen, this will be pursued by applying the pleasure design methodology. Apart from the objective to come up with a kitchen concept, attention will be given to study, compare and discuss the relation and compatibility between different methods and design philosophies.  

    The project resulted in a conceptual kitchen aimed to be suitable for nearly all people. The design was approached through various angles to obtain a broad variety of solutions, which was combined into one kitchen concept, to comply with the demands that a future user may have. The main aspects taken upon are the layout, storage solutions that require minimum effort and a stove and sink solution.

    The kitchen concept complies with the predetermined requirements set forth in the project specifications. Extra attention was put into the storage methods. Not necessarily in the amount, although most space was taken advantage of, but in the ways the user can use the storage spaces. The stove and sink are located on a height-adjustable platform for maximum comfort and adaptation to the user. The layout was determined according to the space needed for mobility, storage and function.

  • 143.
    Fornlöf, Veronica
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. GKN Aerospace.Engine Systems.
    Galar, Diego
    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.
    Almgren, Torgny
    GKN Aerospace Engine Systems.
    Aircraft engines: A maintenance trade-off in a complex system2015Conference paper (Refereed)
    Abstract [en]

    An aircraft engine is a system of systems with several degrees of complexity. It is important to perform the correct amount of maintenance at each individual maintenance event. A mathematical replacement model is used to ensure that the correct amount of maintenance is performed. However, this paper shows that the reliability of this model could be improved if there were a better way to estimate the life length of on-condition maintained engine parts.

  • 144.
    Fornlöf, Veronica
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. GKN Aerospace.
    Galar, Diego
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Luleå University of Technology.
    Syberfeldt, Anna
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Almgren, Torgny
    GKN Aerospace.
    On-Condition Parts versus life limited parts: A trade off in aircraft engines2016In: Current Trends in Reliability, Availability, Maintainability and Safety: An Industry Perspective / [ed] U. Kumar, A. Ahmadi, A. K. Verma & P. Varde, 2016, p. 253-262Conference paper (Refereed)
  • 145.
    Fornlöf, Veronica
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. GKN Aerospace Engine Systems, Trollhättan, Sweden.
    Galar, Diego
    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.
    Almgren, Torgny
    GKN Aerospace Engine Systems, Trollhättan, Sweden.
    RUL estimation and maintenance optimization for aircraft engines: A system of system approach2016In: International Journal of Systems Assurance Engineering and Management, ISSN 0975-6809, E-ISSN 0976-4348, Vol. 7, no 4, p. 450-461Article in journal (Refereed)
    Abstract [en]

    An aircraft engine is a system of systems with several degrees of complexity. It is important to perform the correct amount of maintenance at each individual maintenance event. A mathematical replacement model is used to ensure that the correct maintenance is performed. The reliability of the results from the mathematical replacement model will be improved if there is a better way to estimate the life length for on-condition engine parts.

  • 146.
    Fornlöf, Veronica
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. GKN.
    Sandberg, Ulf
    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.
    Almgren, Torgny
    GKN Aerospace Engine Systems.
    More reliable aircraft engine maintenance optimization by a classification framework for on-condition parts2014In: Proceedings of the 6th Swedish Production Symposium, SPS14, Gothenburg, Sweden, Chalmers , 2014Conference paper (Refereed)
  • 147.
    Forsell, Hanna
    et al.
    University of Skövde, School of Technology and Society.
    Åkebäck, Malin
    University of Skövde, School of Technology and Society.
    Development of an Intuitive Grader Control2012Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This project has been carried out in cooperation with Volvo Construction Equipment. A new control intended to give an intuitive understanding for the new generation of operators of how to handle the motor grader has been developed. The project includes parts of the development process, idea to finished concept.

    The project started with a thorough study of the functions of motor graders not only those built by Volvo but also those from the biggest competitors. Interviews were made with operators about today’s and future controls of graders. In comparison the competitors seem to offer better controls both from ergonomic and cognitive points of view.

    Hitherto too little interest has been focused by design engineers in problems of the operators. Operators are exposed to wear and tear when driving the graders and they also have difficulties driving the machines all because of the design of the manoeuvring device.

    From the start to the final concept a great variety of people has been involved in this project e.g. young and old operators, scientists and constructors resulting in a large spread of ideas.

    The final concept is a new thinking control with respect to the combination of functionality, ergonomics and intuitivety.

  • 148.
    Frantzén, Marcus
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    A real-time simulation-based optimisation environment for industrial scheduling2013Doctoral thesis, monograph (Other academic)
    Abstract [en]

    In order to cope with the challenges in industry today, such as changes in product diversity and production volume, manufacturing companies are forced to react more flexibly and swiftly. Furthermore, in order for them to survive in an ever-changing market, they also need to be highly competitive by achieving near optimal efficiency in their operations. Production scheduling is vital to the success of manufacturing systems in industry today, because the near optimal allocation of resources is essential in remaining highly competitive.

     

    The overall aim of this study is the advancement of research in manufacturing scheduling through the exploration of more effective approaches to address complex, real-world manufacturing flow shop problems. The methodology used in the thesis is in essence a combination of systems engineering, algorithmic design and empirical experiments using real-world scenarios and data. Particularly, it proposes a new, web services-based, industrial scheduling system framework, called OPTIMISE Scheduling System (OSS), for solving real-world complex scheduling problems. OSS, as implemented on top of a generic web services-based simulation-based optimisation (SBO) platform called OPTIMISE, can support near optimal and real-time production scheduling in a distributed and parallel computing environment. Discrete-event simulation (DES) is used to represent and flexibly cope with complex scheduling problems without making unrealistic assumptions which are the major limitations of existing scheduling methods proposed in the literature.  At the same time, the research has gone beyond existing studies of simulation-based scheduling applications, because the OSS has been implemented in a real-world industrial environment at an automotive manufacturer, so that qualitative evaluations and quantitative comparisons of scheduling methods and algorithms can be made with the same framework.

     

    Furthermore, in order to be able to adapt to and handle many different types of real-world scheduling problems, a new hybrid meta-heuristic scheduling algorithm that combines priority dispatching rules and genetic encoding is proposed. This combination is demonstrated to be able to handle a wider range of problems or a current scheduling problem that may change over time, due to the flexibility requirements in the real-world.  The novel hybrid genetic representation has been demonstrated effective through the evaluation in the real-world scheduling problem using real-world data.

  • 149.
    Frantzén, Marcus
    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.
    Production simulation education using rapid modeling and optimization: Successful studies2015In: 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, p. 3526-3537Conference paper (Refereed)
    Abstract [en]

    A common issue facing many simulation educators is that students usually spend excessive time to struggle with the programming and statistic parts of the simulation courses, and simply very little time to learn running systems analysis. If the students are coming from industry, and not the campus, then the problem becomes even worse. We observed this problem around 2005 and started to develop a new simulation software, a factory conceptual design toolset, partly aimed to address this problem. A new set of educational courses has since then been developed around the software for teaching production systems analysis, with both the campus students and managers/engineers from industry in mind. In this paper, we briefly introduce the software and share our experiences and some representative, successful studies conducted by the students in the past years.

  • 150.
    Frydén, Cecilia
    et al.
    University of Skövde, School of Engineering Science.
    Omri, Nadia
    University of Skövde, School of Engineering Science.
    Effektivisering av konstruktörens arbete i produktutvecklingsprocessen med hjälp av 3D-modeller och detaljritningar2017Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This project was made for the Bachelor Degree Project in Product Design Engineering course at the University of Skövde by Cecilia Frydén and Nadia Omri in cooperation with the engineering company ÅF during the spring of 2017. ÅF’s designers spends several hours creating 3D-models and detail drawings as manufacturing information for the manufacturing phase of the product development. Some of this time is suspected to be spent unnecessary since some of the information generated by the designers might not be used during the manufacturing process. The aim of the project is to generate a solution to increase the efficiency of the designer’s workflow while generating Product Manufacturing Information (PMI) without compromising the manufacturer’s understanding of the information. Research upon the product manufacturing information generation and handling was done in order to identify its main issues. Observation and interviews were done in order to identify its users and clarify the main purpose of the manufacturing information. The result provides reduced PMI in the 3D-model and uses a 3D-PDF to communicate the PMI to the manufacturers. This was decided from evaluations with the manufacturers and designers and is believed to improve the communication between them but also to make the designer’s workflow more efficient.

1234567 101 - 150 of 471
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf