his.sePublications
Change search
Refine search result
3456789 251 - 300 of 468
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.
  • 251.
    Koskenranta, Mikael
    University of Skövde, School of Technology and Society. University of Skövde, School of Engineering Science.
    Optimisation of ceiling attachment for AVPOS using FEA2015Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    In product manufacture and assembly it is important to lower materials usage and assembly timewhile retaining a safety margin against structural failure. In this project the ceiling attachment of theAVPOS offloading arm is redesigned based on objectives identified by Löfs Specialmaskiner. Theoriginal ceiling attachment is analysed using finite element analysis to identify any structuralweaknesses to be addressed during redesign. Based on information gained during the FEA threeconcepts are generated and rated based on their estimated assembly times, material usage, partscount and the cutting length for machining.One concept is selected for further topology optimisation and iterative FEA, where material isremoved from the selected concept design while maintaining safety objectives. The optimised designdeveloped during this project is shown to have a lower number of parts, lower usage of material andassembly time while retaining an overall FOS value of 4.In addition to redesigning the ceiling attachment, alternative bearings are also investigated whichchanges the existing ball bearings to a self-aligning sliding bearing with self-lubricating properties,lowering the machining tolerances as well as lowering the needs for service.This project contributes to lowering material usage and ease of assembly in the product AVPOS thatis manufactured by Löfs Specialmaskiner. The redesigned ceiling attachment along with thesuggested bearings will likely simplify future manufacturing as well as lower any concerns for damageto people and property as a result of structural failure.

  • 252.
    Krantz, Johan
    et al.
    University of Skövde, School of Engineering Science.
    Krantz, Stefan
    University of Skövde, School of Engineering Science.
    Förslag på utformning av Kitt- och Sekvensering inför nästa generations motor: På Volvo Cars i Skövde2016Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Volvo Cars Skövde will in year 2018 implement a new engine model in Skövde plant, which will lead to a greatly increased variety of the articles in the material facade at the production line when the engine variants increases. However, the current material facade will not be able to cope with the future increase of articles. Therefore, design proposals for the handling of the material by using kit- and sequence picking externally from the production line have been proposed. Hence, handling these operations externally may lead to an efficient material flow, but also enables handling more articles when the engine variants increase.

    The main objective of the project was to develop proposals on how workplace design for a kit- and sequence picking station may look like, and how the flow of material should be handled to and from these stations. To implement this, a form of a PDCA-method has been used to structure the work. Relevant literature on the theory and studies in similar areas has been reviewed to gather knowledge in this area. Successful methods used in other studies, i.e. interviews, observations and benchmarking, were also used in this project to collect data.

    The results based on the collected data generated, present different layout suggestions of a kit- and sequence picking station, with regard to quality assurance and efficiency of the picking patterns, ergonomics, reliability of delivery and the total area required for these picking stations. It will also manage the flow of materials to and from these stations that should be handled in an efficient way. Prototype sketches of proposed way of transport and aid for the material handling have been developed for the company, which will be a base for continued work before the implementation of the next generation engine in year 2018. 

  • 253.
    Kälström, Matilda
    University of Skövde, School of Engineering Science.
    UTVECKLING AV EXKLUSIV KLÄDKAMMARE OCH FÖRVARINGSLÖSNING FÖR PRIVATHEM2015Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Design Engineering student Matilda Kälström has developed a range of storage solutions for walk-in closets where the target group for the project is the company’s existing customer base. During the project a basic feasibility study was done to determine the project requirements, identify competitors and find out what demands and requests the customers have. Example of demand was that the product should provide an overview of the content of the walk-in-closet. A literature study was done to gather information about storage, man's relationship to its home and architecture. Identified information was that it's very important for the human to be able to design their home according to their needs and a good guideline to structure storage is to place the clothes according to where on the body they are used.

    A central part of the project is Kansei engineering, which is a concept of connecting peoples’ perceptions to products' design. It has been used in surveys to find out what the customers want to experience, it has been used for idea generation and it has been used to find out if the results gave desirable experiences. The survey results revealed that desirable experiences of a walk-in closet is luxurious, classic, stylish and comfortable. The meaning of these words were used from the National Encyclopedia to make mood boards which then were used to generate ideas.

    The development of ideas were made in three stages with different methods. After each stages the concepts were evaluated and the results were used in the next stage. The methods that were used was for example personas, scenarios, function trees and morphological table. The evaluations was performed with the company, the method PNI and a weighting matrix.

    The result is a collection of twelve modules that customers can combine in their own way of walk-in closets. Four different cabinet modules, two different “storage islands”, two seats, a dressing table, a chest of drawers for jewelries, a shoe rack and a mirror shelf. To finally find out if the result gives the perceptions and experiences that is desirable an evaluation was done with twelve people, mostly students at the University of Skövde. Two different mounting of the modules in the form of a "female" and "male" walk-in-closets were shown. With their own words they were about to describe what impressions they had of the pictures and tell what they thought of these walk-in-closets. The participants' response strengthened the project's results and confirmed that the impressions and experiences were desirable. 

  • 254.
    Kärrlander, Daniel
    et al.
    University of Skövde, School of Engineering Science.
    Nordström, Marcus
    University of Skövde, School of Engineering Science.
    Utveckling av fiberoptisk ljusgenomföring för lägenhetsdörr2017Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This is a report which covers the bachelor degree project in Product Design Engineering at University of Skövde. The project is conducted in cooperation witha company that manufactures doors and wants to expand their accessory rangewith a product in the market segment between windows and LED-lights toilluminate the very entrance of an apartment and provide the user with sufficientlight. The development process for this product began with a comprehensiveprestudy followed by identification of relevant environments, collection of targetdata through measurements of illumination, and theoretical calculations ofproduct geometries such as light collecting area. The combined knowledge led toa generation stage, evaluation stage and prototype production. The result becamesubstandard and did not reach the desired lighting effect with the identifiedboundary conditions due to unforeseen power losses. If the product is taken outof these boundaries and instead used in more favorable conditions, the result issignificantly better.The conclusion is that passive collection of diffused light is possible but noteffective and above all incompatible with, in this case, high security and demandsfor low costs.

  • 255.
    Ladrón de Guevara Muñoz, M. Carmen
    et al.
    University of Skövde, School of Engineering Science.
    Martín Márquez, Javier
    University of Skövde, School of Engineering Science.
    Mini-grid system study applied to a stand-alone house located in Málaga, Spain2015Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    A study of an off-grid photovoltaic system for the electrification of a stand-alone single residential house in a rural area located in the city of Málaga, Spain, is presented. The load of an average family house is analysed keeping in mind the available solar energy at this location. A preliminary sizing of the system is carried out considering predefined values for the efficiency of the different technologies employed in the system: photovoltaic (PV) array, batteries as energy storages, inverters to convert the energy obtained from the sun, and diesel gensets to ensure supply under any circumstances. Later, precise brands of the available technologies in the market are selected, and the system is re-sized using the new parameters. The life cycle cost of the mini-grid (MG) system shows that the amortization of the system in 20 years for a stand-alone house is not possible. Although it is not confirmed that 20 years will be sufficient to make the system profitable, other aspects are considered and discussed in terms of their feasibility in Málaga.

  • 256.
    Lageholm, Joel
    et al.
    University of Skövde, School of Engineering Science.
    Dia, Mohammed
    University of Skövde, School of Engineering Science.
    Hållfasthetsanalys och vidareutveckling av skopa för traktorer med frontlastare2018Independent thesis Basic level (university diploma), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A bucket, designed and constructed by the company Kellfri AB for all-round usage with front-end loader equipped tractors, has been analyzed via finite element analysis in Creo Parametric. Possibilities of mass reduction, suitability in the placement of an additional detail in the upper parts of the bucket and potential strength problems in the construction was investigated. The project was initialized during the prototyping-phase of product development and at the time the bucket was considered to be over dimensioned by the company with regard to their earlier prototype-testing. Static analysis was done for three separate models; The Company’s own CAD-model, for which the strength of the bucket, as it was originally designed, was evaluated. A second model was made for the use of iterative changes in the construction, each followed by an analysis, to test different solutions for reducing the buckets mass without compromising strength and to address strength issues found in the original model. A third model, comprised of a simplified section of the buckets front, was then used to further evaluate and address the most critical of the strength problems that was found. The bucket was, at the end of the project, considered to be inadequately dimensioned for one of the features of the suggested front-end loader model. Suggestions was therefore given, with probable uncertainties accounted for, regarding a suitable area for mass reduction, changes in the design with the possibilities of cost-reduction by simplifying the manufacturing and assembly processes and also actions to be made in regard of strength problems found. Placement of the upper part-detail was considered safe and therefore given a suggested shape.

  • 257.
    Land, Niklas
    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.
    Torgny, Almgren
    GKN Aerospace Sweden AB, Trollhättan, Sweden.
    Vallhagen, Johan
    Volvo Group Trucks Operations, AB Volvo, Gothenburg, Sweden.
    Virtual Human-Robot Collaboration: The Industry's Perspective on Potential Applications and Benefits2019In: Advances in Manufacturing Technology XXXIII: Proceedings of the 17th International Conference on Manufacturing Research, incorporating the 34th National Conference on Manufacturing Research, September 10–12, 2019, Queen’s University Belfast, UK / [ed] Yan Jin, Mark Price, Amsterdam: IOS Press, 2019, Vol. 9, p. 161-166Conference paper (Refereed)
    Abstract [en]

    Two keystones of Industry 4.0 are the increased use of autonomous robots and advanced simulation software. Human-Robot Collaboration (HRC) combines the strengths of humans and robots, opening up application areas that previously could not be automated. However, the realization of HRC on industrial shop floors is held back by several challenges: safety, trust, the need for intuitive interfaces, and design methods. This study investigates the automotive industry’s perspective on relevant application areas and potential benefits of HRC. The data were collected through a survey of 185 participants from a variety of working roles in the automotive industry. The results of the study indicate that participants from the automotive industry consider that the areas best suited to the implementation of collaborative robots are material handling, assembly, and quality control, with potential benefits in ergonomics, efficiency, and quality. The results can be used for the development of a future virtual HRC simulation model.

  • 258.
    Larsson, Carina
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Communicating performance measures: Supporting continuous improvement in manufacturing companies2017Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Manufacturing enterprises are a key driver of economic growth (Eurostat, 2016). Implementing continuous improvement (CI) is commonly used to increase competitiveness (Hyland et al., 2007), but despite the well-known theory of CI, many manufacturing companies fail in implementing it (Bhasin, 2012; Nordin et al., 2012; Tiwari et al., 2007).

    An identified critical success factor in CI implementation is the evaluation of performance, including the performance evaluation system itself, the linkage between targets at different company levels, and continual evaluation of performance (Bakås et al., 2011; Scherrer-Rathje et al., 2009; Ukko et al., 2009). Another critical success factor in CI implementation is the communication of performance measures (Bakås et al., 2011; Ukko et al., 2009).

    This research explores the communication of performance measures. The aim is to support CI by improving the communication of performance measures, and to this end, this thesis concentrates on identifying the main challenges in the communication of performance measures supporting CI. The research scope is manufacturing companies in general, and manufacturing SMEs in particular. The relevant literature concerning the communication of performance measures in manufacturing companies is identified and summarized. Also, current practice is explored, focusing on how performance measures are communicated in manufacturing companies, and whether and how the communication supports CI. This has been done to identify divergences between current practice and theory. Finally, theory and empirical findings are synthesized to identify some of the main challenges to be addressed in order to succeed in CI.

    The main task is to support CI efforts in manufacturing SMEs, eliminating the identified divergences in the communication of performance measures by adapting these measures to these manufacturing SMEs. These challenges can be summarized as follows: 

    - using both financial performance measures as well as objective and subjective, non-financial performance measures  - aligning performance measures with strategy and targets  - integrating all performance measure communication, as related to both daily performance and CI, in the same communication loop.  - forming two-way communication channels between managers and operators  - aligning oral and written communication channels  - exploring how information systems can facilitate the communication of performance measures  - using and optimizing the visual communication of performance measures

  • 259.
    Larsson, Carina
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. University of Jönköping.
    Säfsten, Kristina
    University of Jönköping.
    Visual communication of performance meaures supporting continuous improvement: Challenges and opportunities for manufacturing SMEs2016Conference paper (Refereed)
    Abstract [en]

    This paper provides a holistic view of visual communication of performance measures supporting continuous improvement in manufacturing SMEs. This is done by a theoretical part with a literature review, and an empirical part with case studies, including both the managers’ and the operators’ perspectives, and by focusing on manufacturing SMEs. The paper identifies five challenges and one opportunity in visual communication that SMEs perceive when using visual communication of performance measures, supporting continuous improvement.

  • 260.
    Larsson, Carina
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. School of Engineering, Jönköping University.
    Säfsten, Kristina
    School of Engineering, Jönköping University.
    Syberfeldt, Anna
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Performance measurement communication supporting lean production in SMEs2014In: Performance management: Designing the high-performing organization, 2014, p. 714-725Conference paper (Refereed)
    Abstract [en]

    Purpose

    The aim of this paper is to provide an overview of the current status of performance measurement communication to support lean production in SMEs.

    Design/methodology/approach

    The paper is based on theoretical and empirical studies. A literature review of existing research in performance measurement communication, focusing on lean production in SMEs, was carried out. The empirical part is based on interviews with both managers and operators in SMEs in the south of Sweden working with lean production. Twenty-four interviews in eight companies / plants were carried out.

    Findings

    The paper provides a structured overview of current research in performance measurement communication. Performance measurement communication was categorised into three parts, which taken together could support lean production implementation in SMEs. It can be concluded that, although all existing research in performance measurement and communication, there is no operational guideline of how to communicate performance measurement. From the interviews it can be seen that the companies have improved their performance measurement communication during the lean production implementation, but that there is no common way of communicating performance measurements in SMEs.

  • 261.
    Larsson, Carina
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Säfsten, Kristina
    Högskolan i Jönköping.
    Syberfeldt, Anna
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Performance measurement follow-up supporting continuous improvements in manufacturing companies: a systematic review2015In: 22nd EurOMA conference: Operations management for sustainable competitiveness / [ed] Gerald Reiner, 2015Conference paper (Refereed)
    Abstract [en]

    Performance measurement has been paid a lot of attention. This paper provides a systematic review of existing research in performance measurement follow-up, which so far has been less treated. The paper suggests a categorization of the follow-up phase into the performance measurement system, input to and output from the system, and operational activities. It is concluded that there is a lack of research concerning the operational activities in the follow-up phase. It is also concluded that most of the research concerning follow-up of performance measurement does not support continuous improvement explicitly, but concerns performance measurement follow-up in general.

  • 262.
    Leffler, Karin
    University of Skövde, School of Technology and Society.
    Shear Behaviour of Adhesive Layers2005Licentiate thesis, monograph (Other scientific)
    Abstract [en]

    An experimental method to determine the complete stress versus deformation relation for a thin adhesive layer loaded in shear is presented. The work is based on a classical specimen geometry, i.e. the end-notch flexure specimen (ENF-specimen) and the experiments are evaluated based on an inverse method. By studying the energy balance at the crack tip an expression for the energy release rate is derived. The theory considers the effects of a flexible adhesive layer and is based on beam theory. From the energy release rate the stress-deformation relation is derived using the inverse method.

    Quasi-static experiments are performed using a servo-hydraulic testing machine. The deformation process at the crack tip is monitored during the experiments by use of a CCD-camera attached to a microscope. The method requires differentiation of the energy-deformation relation, therefore a Monte-Carlo simulation is performed to investigate how small errors in the data acquisition system affects the final stress-deformation relation. Small errors in the measurement of the force and shear deformation give small effects on the final stress-deformation relation.

    Experiments on three different geometries of the specimen are performed. The experiments give consistent results. It is shown that if the process zone in front of the crack tip is large, then the stress-deformation relation does not depend on the dimensions of the adherends. Thus, the constitutive relation can be considered to be a property of the adhesive layer.

  • 263.
    Lidberg, Simon
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Volvo Car Corporation, Sweden.
    Aslam, Tehseen
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Pehrsson, Leif
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Evaluating the impact of changes on a global supply chain using an iterative approach in a proof-of-concept model2018In: Advances in Manufacturing Technology XXXII: Proceedings of the 16th International Conference on Manufacturing Research, incorporating the 33rd National Conference on Manufacturing Research, September 11–13, 2018, University of Skövde, Sweden / [ed] Peter Thorvald, Keith Case, Amsterdam: IOS Press, 2018, p. 467-472Conference paper (Refereed)
    Abstract [en]

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

  • 264.
    Lidberg, Simon
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Aslam, Tehseen
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Pehrsson, Leif
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Optimizing real-world factory flows using aggregated discrete event simulation modelling: Creating decision-support through simulation-based optimization and knowledge-extraction2019In: Flexible Services and Manufacturing Journal, ISSN 1936-6582, E-ISSN 1936-6590Article in journal (Refereed)
    Abstract [en]

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

  • 265.
    Lidberg, Simon
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Volvo Car Corporation, Skövde, Sweden.
    Pehrsson, Leif
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Frantzén, Marcus
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Applying Aggregated Line Modeling Techniques to Optimize Real World Manufacturing Systems2018In: Procedia Manufacturing, E-ISSN 2351-9789, Vol. 25, p. 89-96Article in journal (Refereed)
    Abstract [en]

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

  • 266.
    Lidberg, Simon
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Pehrsson, Leif
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Using Aggregated Discrete Event Simulation Models and Multi-Objective Optimization to Improve Real-World Factories2018In: Proceedings of the 2018 Winter Simulation Conference / [ed] M. Rabe, A. A. Juan, N. Mustafee, A. Skoogh, S. Jain, B. Johansson, IEEE, 2018, p. 2015-2024Conference paper (Refereed)
    Abstract [en]

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

  • 267.
    Lind, Carl Mikael
    et al.
    Unit of Occupational Medicine, Karolinska Institutet, Stockholm, Sweden / Division of Ergonomics, KTH Royal Institute of Technology, Huddinge, Sweden.
    Sandsjö, Leif
    Faculty of Caring Science, Work Life and Social Welfare, University of Borås, Sweden / Design & Human Factors, Department of Industrial and Materials Science, Chalmers University of Technology, Gothenburg, Sweden.
    Mahdavian, Nafise
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Hanson, Lars
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Scania CV, Södertälje, Sweden.
    Olivares, Jozé Antonio Diaz
    Division of Ergonomics, KTH Royal Institute of Technology, Huddinge, Sweden.
    Yang, Liyun
    Unit of Occupational Medicine, Karolinska Institutet, Stockholm, Sweden / Division of Ergonomics, KTH Royal Institute of Technology, Huddinge, Sweden.
    Forsman, Mikael
    Unit of Occupational Medicine, Karolinska Institutet, Stockholm, Sweden / Division of Ergonomics, KTH Royal Institute of Technology, Huddinge, Sweden.
    Prevention of Work: Related Musculoskeletal Disorders Using Smart Workwear – The Smart Workwear Consortium2019In: Human Systems Engineering and Design: Proceedings of the 1st International Conference on Human Systems Engineering and Design (IHSED2018): Future Trends and Applications, October 25-27, 2018, CHU-Université de Reims Champagne-Ardenne, France / [ed] Tareq Ahram, Waldemar Karwowski, Redha Taiar, Springer, 2019, Vol. 876, p. 477-483Conference paper (Refereed)
    Abstract [en]

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

  • 268.
    Lindell Wallgren, Ida
    University of Skövde, School of Engineering Science.
    Alternativt material i behållare för konstgödselrampspridare: Förarbete för prototyp2015Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

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

  • 269.
    Linder, Jonas
    University of Skövde, School of Engineering Science.
    Kyleffektivisering av en havsvattenanläggning: Havets Hus i Lysekil2016Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

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

  • 270.
    Lindström, Adam
    University of Skövde, School of Engineering Science.
    Undersökning av mekanisk belastning på ytmonterade elektriska komponenter vid screentryckning2016Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

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

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

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

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

  • 271.
    Linero Jiménez, Adriano
    University of Skövde, School of Engineering Science.
    DEVELOPMENT OF A MODEL OF THE DEGRADATION OF THE MECHANICAL PROPERTIES OF POLYOXYMETHYLENE (POM) IN THE PRESENCE OF BIODIESEL2014Independent thesis Advanced level (degree of Master (One Year)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

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

  • 272.
    Lingman, Simon
    et al.
    University of Skövde, School of Engineering Science.
    Einemo Swahn, Dennis
    University of Skövde, School of Engineering Science.
    Utveckla förbättringsunderlag och utöka utnyttjandegraden för en maskincell2019Independent thesis Basic level (university diploma), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

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

  • 273.
    Linnéusson, Gary
    University of Skövde, School of Technology and Society.
    Literature Review on System Dynamics and Simulation2006Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This report is a literature review of System Dynamics (SD) and simulation, with enough information so the receiver can form a mental model of his own of what SD is.

    It started in the 1950s by Jay W. Forrester at the Massachusetts Institute of Technology, a devoted man that through his career always sought for practical applications of theory and gained skills. The key in why this new way of approaching problems in complex systems was its strength in capturing the dynamics, through the use of a computer to run a modeled system for a set of time and experimenting on which variables to modify or rearrange. SD methodology uses the theory of information feedbacks (i.e. closed loop structures), and the structure is based on the decision making processes or policies that interrelate in ways in the system. The model is valid if it shows the same dynamic behavior as the real system.

    In the report you will find some history and background to SD and the contents of the methodology, some application areas and two models; of which simulation is performed, one made by Jay Forrester and one very simple made by Gary Linnéusson.

    Main purpose with this review was to find out if SD could serve as a tool for simulating organizational development. If it can, further research on how will be part of a doctoral study project within CAPE, an Industrial Graduate School in Advanced Production Engineering. This due to that Arkivator Falköping AB is interested in to conduct an attendee in that School which would research on: "developing a method that would support management in decisions to develop their organization". The result of this review shows that SD can be a tool to treat that issue, one of very few tools that consider interrelations and interactions within organizational systems.

  • 274.
    Linnéusson, Gary
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Towards strategic development of maintenance and its effects on production performance: A hybrid simulation-based optimization framework2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

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

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

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

  • 275.
    Linnéusson, Gary
    et al.
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre. Production Engineering and Production Preparation, Arkivator AB, Falköping, Sweden .
    Jägstam, Mats
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Näsström, C.
    Production Engineering and Production Preparation, Arkivator AB, Falköping, Sweden.
    Cutting Tool Management: A Dynamic Assessment of Opportunities for Improvement2008In: Proceedings of the 18th International Conference on Flexible Automation and Intelligent Manufacturing: FAIM 2008 / [ed] Leo J. de Vin, 2008, Vol. 2, p. 1084-1091Conference paper (Refereed)
    Abstract [en]

    Lack of time due to daily problems in need of attention restrains proper assessments of improvement opportunities. There is neither proper support at hand to deal with the dynamic complexity of human activity and systems in use. This paper explores if system dynamics simulation can be used to model tooling problems on a management problem level at a manufacturer and evaluates its use. System dynamics is a methodology designed to aid understanding of dynamically complex problems and increases decision making impact. The results focus on the achieved models which prove to have sense behaviour despite lack of thorough data. In conclusion the applied method provides with an analysis of complex problem situations applicable for a decision support, otherwise performed through good guessing. Main characteristics from reality have been included in model and an experimental laboratory to test future policies on achieved.

  • 276.
    Linnéusson, Gary
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Aslam, Tehseen
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Engineering Science.
    Investigating Maintenance Performance: A Simulation Study2016In: Proceedings of the 7th Swedish Production Symposium, 2016Conference paper (Refereed)
    Abstract [en]

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

  • 277.
    Linnéusson, Gary
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Aslam, Tehseen
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    A hybrid simulation-based optimization framework for supporting strategic maintenance to improve production performance2019In: European Journal of Operational Research, ISSN 0377-2217, E-ISSN 1872-6860Article in journal (Refereed)
    Abstract [en]

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

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

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

  • 278.
    Linnéusson, Gary
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Aslam, Tehseen
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Justifying Maintenance Studying System Behavior: A Multipurpose Approach Using Multi-objective Optimization2017In: 35th International Conference of the System Dynamics Society 2017: Cambridge, Massachusetts, USA 16 - 20 July 2017 / [ed] J. Sterman, N. Repenning, Curran Associates, Inc., 2017, Vol. 2, p. 1061-1081Conference paper (Refereed)
    Abstract [en]

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

  • 279.
    Linnéusson, Gary
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Jönköping University, School of Engineering, Sweden.
    Aslam, Tehseen
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Quantitative analysis of a conceptual system dynamics maintenance performance model using multi-objective optimisation2018In: Journal of Simulation, ISSN 1747-7778, E-ISSN 1747-7786, Vol. 12, no 2, p. 171-189Article in journal (Refereed)
  • 280.
    Linnéusson, Gary
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Jönköping University, Sweden.
    Aslam, Tehseen
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Relating strategic time horizons and proactiveness in equipment maintenance: a simulation-based optimization study2018In: Procedia CIRP, ISSN 2212-8271, E-ISSN 2212-8271, Vol. 72, p. 1293-1298Article in journal (Refereed)
    Abstract [en]

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

  • 281.
    Linnéusson, Gary
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Aslam, Tehseen
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Towards strategic development of maintenance and its effects on production performance by using system dynamics in the automotive industry2018In: International Journal of Production Economics, ISSN 0925-5273, E-ISSN 1873-7579, Vol. 200, p. 151-169Article in journal (Refereed)
    Abstract [en]

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

  • 282.
    Liu, Yu
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Syberfeldt, Anna
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Strand, Mattias
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    A Review of Simulation Based Life Cycle Assessment in Manufacturing Industry2018In: Advances in Manufacturing Technology XXXII: Proceedings of the 16th International Conference on Manufacturing Research, incorporating the 33rd National Conference on Manufacturing Research, September 11 – 13, 2018, Skövde, Sweden / [ed] Peter Thorvald, Keith Case, Amsterdam, Berlin, Washington,DC: IOS Press, 2018, Vol. 8, p. 381-386Conference paper (Refereed)
    Abstract [en]

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

  • 283.
    Lorente Zamora, Joanes
    et al.
    University of Skövde, School of Engineering Science.
    Sorarrain Aguirrezabala, Gorka
    University of Skövde, School of Engineering Science.
    Modelling and emulation of industrial electric, pneumatic and hydraulic system2018Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

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

  • 284.
    Lundberg, Anna
    et al.
    University of Skövde, School of Engineering Science.
    Oldenburg, Martina
    University of Skövde, School of Engineering Science.
    Utveckling av golvkonsol för elbil2017Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

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

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

  • 285.
    Lundberg, Daniel
    et al.
    University of Skövde, School of Technology and Society.
    Mattsson, Tobias
    University of Skövde, School of Technology and Society.
    Klämskydd: Minimering av klämrisk2012Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    On behalf of the client, a design proposal regarding pinch protection is developed. This follows the recommendationsfrom Boverket to improve the pinch security in doors. The recommendations are based ona report by Konsumentverket. The report illustrates that approximately 50% of all the pinch related accidentshappens on the lock side of the door, while there are few solutions to minimize the risk of pinchingat the lock side.A product comparison is carried out to see what kind of solutions the market offers. Practical tests andobservations of door closure are performed.Concept development begins with the production of simple sketches. Inspiration to the pinch protectionsare taken from both students on the nearby engineering programs, family and friends as well as of variousvisits to retailers. In order to compare the different concepts, a balanced concept selection matrix is used.From a selection of six concepts three is chosen to go through further developed.Finally, one concept laid the foundation for a design proposal. The concept is based on a pinch protectionwith air cushioning, which is activated when someone forcefully try to close the door. Pinch protectionminimizes the risk of injury to the user between door leaf and the lock side of the door. A FEM-analysisis performed on the included parts to analyze the strength of materials. Function is tested by investigatingif compression occurs in the prototypes created. The tests show that compression occurs.The results of the thesis lead to a design proposal with accompanying drawings and materials. The designproposal should be mounted under the top edge of the frame. The pinch protection dampens the doorsmovement by using compression inside the chamber, at a slow movement no compression occurs, whichmeans that the door can be closed normally.The chambers and the piston rod can been made in zinc alloy ZA-27 if reconstruction is made before thecasting. A PVC elastomer is used for molding the damping plate, also a conic pressure spring and eightscrews for assembly are used.Construction of the proposals strength need to be reviewed to ensure adequate strength, as a future workthe FEM analysis shows that the material is exposed to very high tension.

  • 286.
    Lundgren, Daniel
    et al.
    University of Skövde, School of Technology and Society.
    Persson, Michael
    University of Skövde, School of Technology and Society.
    Kvalitetsprovning av låskulor till hydrauliska snabbkopplingar2012Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    A company that manufactures hydraulic quick-couplings has discovered through regular quality checks that the quality of some of the locking balls for the locking mechanism in the quick couplings suddenly has become insufficient and the locking balls rupture under load. The locking balls are made of stainless steel and if they rupture during usage the consequences can be material damage or even personal injury. The company wants to prevent any quality problems and must therefore ensure that the strength of the locking balls is sufficient. The locking balls are purchased from a subcontractor and the company would therefore like to develop a method for strength testing locking balls delivered to the factory. This thesis aims to help the company in developing such a method. 

    A first step is to investigate the cause of the locking balls rupture. Material analyses are executed by a material laboratory in order to determine what features in the material that causes the ruptures. The analyses shows that rupture is probably caused by an increased brittleness in the material and the brittleness is a consequence of less tempered martensite and a high amount of carbides.

    With the cause of rupture determined, existing methods for testing material properties is studied. It is important that strength testing is carried out with test specimens prepared from the actual locking balls. Otherwise the influence of the locking balls manufacturing process on the material properties is not taking into account. Many of the standardized methods for testing material properties, however, are hard to apply to the locking balls due to the geometry and small dimensions of the locking balls.

    A kind of impact test and compression test is performed. One of the purposes with the tests is to investigate if they are adequate for strength testing the locking balls. The results of the tests, however, are not suitable for comparison. Also, a fatigue test of the locking balls is performed by a repetitive loading of a quick coupling. The fatigue test is, however, time consuming and there are uncertainties in the test results. None of these tests is considered suitable as a strength testing method.

    In this thesis, two recently developed methods for strength testing ceramic balls and the possibility to apply these methods on the locking balls is studied. The study includes an analysis of the stress distribution in a locking ball under load to determine in which region the highest stresses occur. The study provides that only one of the methods is suitable for the locking balls due to differences in preparing the test specimen and which region of the locking ball that is tested in each method.

    The strength testing method that is proposed in this thesis is called the notched ball test (NBT). In NBT a long and narrow notch is cut in a locking ball which is then loaded in compression perpendicular to the notch until rupture occurs. The maximum stress acting at the rupture is calculated and used to determine the strength of the locking ball. NBT is suitable because it can be performed with existing equipment at the company, the test specimen is prepared from actual locking balls and the test uses tensile stresses which is an advantage when brittleness is to be detected in a material.

    An analysis of NBT is performed to determine how material properties and different notch geometries is affecting the test results. The analysis also gives some recommendations for notch geometries that should be used when performing NBT as well as a constant that is used when calculating the maximum stress. Practical experiments of NBT are not carried out in this thesis. Instead, conclusions regarding NBT and recommendations for the company on how they should proceed with NBT are given.

  • 287.
    López Fernández, Antonio José
    et al.
    University of Skövde, School of Engineering Science. University of Málaga.
    López López, Aída
    University of Skövde, School of Engineering Science. University of Málaga.
    Redesign of windows and doors of a convertible car: Hurtan Grand Albaycín redesign2015Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

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

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

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

  • 288.
    Magnusson, Lisa
    University of Skövde, School of Engineering Science.
    DESIGN IMPROVEMENTS OF DISTRIBUTION TRANSFORMERS: How to improve conditions of transportation in Vietnam2014Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

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

  • 289.
    Mahdavian, Nafise
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Development and Evaluation of Digital Ergonomics Tools to Assess Human Work in Real and Virtual Environments: Based on case studies of manual assembly in Swedish automotive companies2018Report (Other academic)
    Abstract [en]

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

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

  • 290.
    Mahdavian, Nafise
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Lind, Carl Mikael
    Unit of Occupational medicine, Karolinska Institutet, Stockholm, Sweden / Division of Ergonomics, KTH Royal Institute of Technology, Huddinge, Sweden.
    Diaz Olivares, Jose Antonio
    Division of Ergonomics, KTH Royal Institute of Technology, Huddinge, Sweden.
    Iriondo Pascual, Aitor
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Brolin, Erik
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Yang, Liyun
    Unit of Occupational medicine, Karolinska Institutet, Stockholm, Sweden / Division of Ergonomics, KTH Royal Institute of Technology, Huddinge, Sweden.
    Forsman, Mikael
    Unit of Occupational medicine, Karolinska Institutet, Stockholm, Sweden / Division of Ergonomics, KTH Royal Institute of Technology, Huddinge, Sweden.
    Hanson, Lars
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Scania CV, Södertälje, Sweden.
    Effect of Giving Feedback on Postural Working Techniques2018In: Advances in Manufacturing Technology XXXII: Proceedings of the 16th International Conference on Manufacturing Research, incorporating the 33rd National Conference on Manufacturing Research, September 11–13, 2018, University of Skövde, Sweden / [ed] Peter Thorvald, Keith Case, Amsterdam, Netherlands: IOS Press, 2018, p. 247-252Conference paper (Refereed)
    Abstract [en]

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

  • 291.
    Marcus, Hesselgren
    et al.
    University of Skövde, School of Engineering Science.
    Vestberg, Victor
    University of Skövde, School of Engineering Science.
    Reducering av ställtider: Verktygshantering2018Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

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

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

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

  • 292.
    Marruecos Sola, Eugenio José
    et al.
    University of Skövde, School of Technology and Society.
    Valenzuela Romero, Juan Diego
    University of Skövde, School of Technology and Society.
    Drop testing applied to adhesive research in automotive structures2007Independent thesis Basic level (degree of Bachelor), 15 points / 22,5 hpStudent thesis
    Abstract [en]

    The design and analysis of drop test to investigate the behaviour of adhesive joints in automotive structures is performed. The drop test is simulated by FE software. The specimen geometry is based on Volvo Car Corp. drop test standard.

    In the drop test machine, a general beam structure is supporting all the parts. The machine includes a lifting system. The test is applied to a pre designed specimen, which will provide the information about adhesive joint strength.

  • 293.
    Martinez Cabrera, Gerardo
    et al.
    University of Skövde, School of Technology and Society.
    Cuevas Melendez, Rafael
    University of Skövde, School of Technology and Society.
    DESIGN OF TEST RIG FOR MEASURING OF CUTTING FORCES2013Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    In this thesis,a design of a portable measuring test rig is developed with the aim of measure the tangential force, the most characteristic component of the cutting force.This test rig can be used in different lathes without any large modification.The design is based on the lever law to transmit the tangential force to a piezoelectric senso rconnected to an amplifier, to a dataa cquisition system and to a computer to obtain the graph of the speed against the tangential cutting force.The sensor is preload using an original fixing screw of the lathe.The results show that the tangential force is measurable using the device. Due to the geometry, when the tangential force rises 100 N, the reaction in the sensor rises approximately 120 N. Using a preload in the sensor of 10 kN, with a tangential force of 500N, the piezoelectric sensor receive about 13 kN.

  • 294.
    Martínez Conde, Sergio
    et al.
    University of Skövde, School of Engineering Science.
    Pérez Luque, Estela
    University of Skövde, School of Engineering Science.
    Exoskeleton for hand rehabilitation2018Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

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

  • 295.
    Marzi, Stephan
    et al.
    Fraunhofer IFAM, Bremen, Germany.
    Biel, Anders
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Hesebeck, Olaf
    Fraunhofer IFAM, Bremen, Germany.
    3D optical displacement measurements on dynamically loaded adhesively bonded T-peel specimens2015In: International Journal of Adhesion and Adhesives, ISSN 0143-7496, E-ISSN 1879-0127, Vol. 56, p. 41-45Article in journal (Refereed)
    Abstract [en]

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

  • 296.
    Marzi, Stephan
    et al.
    Fraunhofer IFAM, Bremen, Germany.
    Hesebeck, Olaf
    Fraunhofer IFAM, Bremen, Germany.
    Brede, Markus
    Fraunhofer IFAM, Bremen, Germany.
    Nagel, Christof
    Fraunhofer IFAM, Bremen, Germany.
    Biel, Anders
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Walander, Tomas
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Stigh, Ulf
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Effects of the bond line thickness on the fracture mechanical behaviour of structural adhesive joints2014In: Proceedings of the Annual Meeting of the Adhesion Society 2014, Adhesion Society , 2014, p. 189-192Conference paper (Refereed)
  • 297.
    Mattsson, Sandra
    et al.
    Chalmers University of Technology.
    Fast-Berglund, Åsa
    Chalmers University of Technology.
    Li, Dan
    Chalmers University of Technology.
    Thorvald, Peter
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Forming a cognitive automation strategy for Operator 4.0 in complex assembly2018In: Computers & industrial engineering, ISSN 0360-8352, E-ISSN 1879-0550Article in journal (Refereed)
    Abstract [en]

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

  • 298.
    Mattsson, Sandra
    et al.
    Chalmers University of Technology, Gothenburg, Sweden.
    Fast-Berglund, Åsa
    Chalmers University of Technology, Gothenburg, Sweden.
    Thorvald, Peter
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    A Relationship Between Operator Performance and Arousal in Assembly2016In: Procedia CIRP, ISSN 2212-8271, E-ISSN 2212-8271, Vol. 44, p. 32-37Article in journal (Refereed)
    Abstract [en]

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

  • 299.
    Melle, Daniel
    et al.
    University of Skövde, School of Engineering Science.
    Johan, Larsson
    University of Skövde, School of Engineering Science.
    Mätningar av kantviksmaskin vid klämningsrörelse2019Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

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

  • 300.
    Mendoza, Ana Isabel
    et al.
    KTH-Royal Institute of Technology, Fibre and Polymer Technology, Stockholm, Sweden.
    Moriana, Rosana
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. KTH-Royal Institute of Technology, Fibre and Polymer Technology, Stockholm / SLU-Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Hillborg, Henrik
    ABB-Corporate Research, Power Technology, Västerås, Sweden.
    Strömberg, Emma
    KTH-Royal Institute of Technology, Fibre and Polymer Technology, Stockholm, Sweden.
    Super-hydrophobic zinc oxide/silicone rubber nanocomposite surfaces2019In: Surfaces and Interfaces, ISSN 2468-0230, Vol. 14, p. 146-157Article in journal (Refereed)
    Abstract [en]

    This study presents comparative assessments on hydrophilic and hydrophobic ZnO nanoparticles and their deposition methods on the surface hydrophobicity of silicone rubber (PDMS) and glass substrates. The influence on the surface hydrophobicity and wettability of all the variables regarding the deposition methodologies and the interaction of the nanoparticles with the substrates were within the scope of this study. The different surfaces created by spraying, dipping and drop-pipetting deposition methods were assessed by static contact angle measurements and contact angle hysteresis from advancing and receding angles, as well as by the calculation of the sliding angle and the surface energy parameters. An accurate methodology to determine the contact angle hysteresis was proposed to obtain repetitive and comparative results on all surfaces. All the measurements have been correlated with the morphology and topography of the different surfaces analysed by FE-SE microscopy. The spray-deposition of hydrophobic ZnO nanoparticles on PDMS resulted in super-hydrophobic surfaces, exhibiting hierarchical structures with micro-and nanometer features which, together with the low surface energy, promotes the Cassie-Baxter wetting behavior. This study provides the fundamental approach to select critically the most promising combination in terms of materials and deposition techniques to create silicone-based super-hydrophobic surfaces with potential to be applied in high voltage outdoor insulation applications.

3456789 251 - 300 of 468
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