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  • 1.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Airborne wear particles from train traffic2010Konferansepaper (Fagfellevurdert)
  • 2.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olander, Lars
    A field investigation of the size and morphology and chemical composition of airborne particles in rail transport2010Konferansepaper (Fagfellevurdert)
  • 3.
    Abid, Muhammad
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.). Högskolan i Gävle, Sweden.
    Relationship between competitive priorities and global supply chain design: A conceptual frameworkManuskript (preprint) (Annet vitenskapelig)
  • 4.
    Abid, Muhammad
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.). Högskolan i Gävle, Sweden.
    Bengtsson, Lars
    Hellberg, Roland
    Dabhilkar, Mandar
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.).
    Factors affecting global supply chain design2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Due to the limited existing knowledge pertaining to the factors which govern localization of operations and capabilities in a global supply chain, the purpose of the paper is to find out which factors and how they jointly affect the design of global supply chains. The relevant literature is reviewed and a concept matrix is developed. Five companies were selected in order to illustrate the issues of global supply chain design. Among them, three companies are considered to have efficient supply chain and less complex products, while the two others are considered to have responsive supply chain and more complex products. The issues discussed with the selected companies cover global sourcing, challenges, technological advancement and issues related to management control. The study identifies about fifty factors that affect global supply chain design, and specifically how theses relate to design decisions on location of factories and production, supplier selection and development, distribution of products and organisation of interfaces along the supply chain. The discrepancies between theory and practice as well as the implications for further research are discussed.

  • 5.
    Aftab, Ahmad
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Mekatronik.
    Andersson, Kjell
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Khan, Suleman
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Mekatronik.
    A stiffness modeling methodology for simulation-driven design of haptic devices2014Inngår i: Engineering with Computers, ISSN 0177-0667, E-ISSN 1435-5663, Vol. 30, nr 1, s. 125-141Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Efficient development and engineering of high performing interactive devices, such as haptic robots for surgical training benefits from model-based and simulation-driven design. The complexity of the design space and the multi-domain and multi-physics character of the behavior of such a product ask for a systematic methodology for creating and validating compact and computationally efficient simulation models to be used in the design process. Modeling the quasi-static stiffness is an important first step before optimizing the mechanical structure, engineering the control system, and performing hardware in the loop tests. The stiffness depends not only on the stiffness of the links, but also on the contact stiffness in each joint. A fine-granular Finite element method (FEM) model, which is the most straightforward approach, cannot, due to the model size and simulation complexity, efficiently be used to address such tasks. In this work, a new methodology for creating an analytical and compact model of the quasi-static stiffness of a haptic device is proposed, which considers the stiffness of actuation systems, flexible links and passive joints. For the modeling of passive joints, a hertzian contact model is introduced for both spherical and universal joints, and a simply supported beam model for universal joints. The validation process is presented as a systematic guideline to evaluate the stiffness parameters both using parametric FEM modeling and physical experiments. Preloading has been used to consider the clearances and possible assembling errors during manufacturing. A modified JP Merlet kinematic structure is used to exemplify the modeling and validation methodology.

  • 6.
    Aftab, Ahmad
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Mekatronik.
    Khan, Suleman
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Mekatronik.
    Andersson, Kjell
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Kinematics and Dynamics of a novel 6-DoF TAU Haptic Device2011Inngår i: Proceedings of the 2011 IEEE International Conference on MechatronicsInternational Conference on Mechatronics, April 13-15, 2011, Istanbul, Turkey, IEEE conference proceedings, 2011, s. 719-724Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents the kinematics and dynamics modeling of a novel hybrid kinematic concept, i.e. the TAU haptic device. This new concept was obtained from the modification of TAU-2 structure proposed by Khan et al. First a kinematic model for inverse and forward kinematics was developed and analyzed. Then an algorithm to solve the close form inverse dynamics is presented using Lagrangian formulation. Numerical simulation was carried out to examine the validity of the approach and accuracy of the technique employed. A trigonometric helical trajectory of 5th order spline was developed in Cartesian space for each degree of freedom of the moving platform in order to verify and simulate the inverse dynamics; the motion of the platform is such that the tool centre point remains on this trajectory while its orientation is changing constantly in roll, pitch and yaw.

  • 7.
    Ahlsén, David
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Marina system.
    Fartygsprojektering och Flytande havsbaserad vindkraft2015Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Den här rapporten behandlar tre områden anknutna till den gemensamma sektorn marina system. Inledningsvis beskrivs sjöfartsnäringens olika delar däribland olika typer av gods och fartygstyper samt sjöfartens aktörer och reglerande organ. Sjöfarten diskuteras med hänsyn till miljö och visar att godstransport till havs är relativt energieffektivt, men att alla typer av gods inte kan motiveras ur ett hållbart perspektiv.

    En inledande fartygsprojektering genomförs för ett transportscenario där 5500 ton kiwifrukt ska transporteras från Nya Zeeland till länder kring Östersjön inom en tidsrymd som garanterar att frukten håller god kvalitet. Fartygstypen är ett kylfartyg dimensionerat att rymma lasten, minimera motstånd och uppfylla stabilitetskriterier från IMO. För att uppfylla transportscenariot är fartyget designat för en marschfart på 20 knop, med ett deplacement på 12500 ton, en längd på 138 m, 21 m i bredd och ett djupgående på 7.7 m.

    Avslutningsvis identifieras kriterier och förutsättningar för flytande havsbaserad vindkraft. Detta med syfte genomföra en inledande projektering av en vindkraftpark stor nog att Gotland kan täcka sin elkonsumtion med endast förnybara energikällor. Parken anläggs längs en ny kabelanslutning mellan Gotland och fastlandet utom synhåll från såväl Gotland, Öland och fastlandet. Området uppfyller krav på vindförhållanden och utgörs av 24 vindkraftverk med kapacitet på 5 MW vardera.

  • 8.
    Ahmad, Aftab
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Effective development of haptic devices using a model-based and simulation-driven design approach2014Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Virtual reality (VR)-based surgical simulators using haptic devices can increase the effectiveness of surgical training for surgeons when performing surgical procedures in hard tissues such as bones or teeth milling. The realism of virtual surgery through a surgical simulator depends largely on the precision and reliability of the haptic device, which reflects the interaction with the virtual model. The quality of perceptiveness (sensation, force/torque) depends on the design of the haptic device, which presents a complex design space due to its multi-criteria and conflicting character of functional and performance requirements. These requirements include high stiffness, large workspace, high manipulability, small inertia, low friction, high transparency, and cost constraints.

    This thesis proposes a design methodology to improve the realism of force/torque feedback from the VR-based surgical simulator while fulfilling end-user requirements.

    The main contributions of this thesis are:

    1. The development of a model-based and simulation-driven design methodology, where one starts from an abstract, top-level model that is extended via stepwise refinements and design space exploration into a detailed and integrated systems model that can be physically realized.

    2. A methodology for creating an analytical and compact model of the quasi-static stiffness of a haptic device, which considers the stiffness of actuation systems, flexible links and passive joints.

    3. A robust design optimization approach to find the optimal numerical values for a set of design parameters to maximize the kinematic, dynamic and kinetostatic performances of a 6-degrees of freedom (DOF) haptic device, while minimizing its sensitivity to variations in manufacturing tolerances and cost, and also satisfying the allowed variations in the performance indices.

    4. A cost-effective approach for force/torque feedback control using force/torque estimated through a recursive least squares estimation.

    5. A model-based control strategy to increase transparency and fidelity of force/torque feedback from the device by compensating for the natural dynamics of the device, friction in joints, gravity of platform, and elastic deformations.

     

  • 9.
    Ahmad, Aftab
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Andersson, Kjell
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    A deterministic and probabilistic approach for robust optimal design of a 6-DOF haptic device2014Inngår i: Proceedings of the ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference--2013: Volume 3 B, 2013, ASME Press, 2014, s. V03BT03A032-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This work suggests a two-stage approach for robust optimal design of 6-DOF haptic devices based on a sequence of deterministic and probabilistic analyses with a multi-objective genetic algorithm and the Monte-Carlo method. The presented model-based design robust optimization approach consider simultaneously the kinematic, dynamic, and kinetostatic characteristics of the device in both a constant and a dexterous workspace in order to find a set of optimal design parameter values for structural configuration and dimensioning. Design evaluation is carried out based on local and global indices, like workspace volume, quasi-static torque requirements for the actuators, kinematic isotropy, dynamic isotropy, stiffness isotropy, and natural frequencies of the device. These indices were defined based on focused kinematic, dynamic, and stiffness models. A novel procedure to evaluate local indices at a singularity-free point in the dexterous workspace is presented. The deterministic optimization approach neglects the effects from variations of design variables, e.g. due to tolerances. A Monte-Carlo simulation was carried out to obtain the response variation of the design indices when independent design parameters are simultaneously regarded as uncertain variables. It has been observed that numerical evaluation of performance indices depends of the type of workspace used during optimization. To verify the effectiveness of the proposed procedure, the performance indices were evaluated and compared in constant orientation and in dexterous workspace.

  • 10.
    Ahmad, Aftab
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Andersson, Kjell
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    An approach to stiffness analysis methodology for haptic devices2011Inngår i: 2011 3rd International Congress on Ultra Modern Telecommunications and Control Systems and Workshops (ICUMT), IEEE conference proceedings, 2011, , s. 8s. 1-8Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this work a new methodology is proposed to model the static stiffness of a haptic device. This methodology can be used for other parallel, serial and hybrid manipulators. The stiffness model considers the stiffness of; actuation system; flexible links and passive joints. For the modeling of the passive joints a Hertzian contact model is introduced for both spherical and universal joints and a simply supported beam model for universal joints. For validation of the stiffness model a modified JP Merlet kinematic structure has been used as a test case. A parametric Ansys FEM model was developed for this test case and used to validate the resulting stiffness model. The findings in this paper can provide an additional index to use for multi-objective structural optimization to find an optimum compromise between a lightweight design and the stiffness performance for high precision motion within a larger workspace.

  • 11.
    Ahmad, Aftab
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Kjell, Andersson
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    A model-based and simulation-driven methodology for design of haptic devices2014Inngår i: Mechatronics (Oxford), ISSN 0957-4158, E-ISSN 1873-4006, Vol. 24, nr 7, s. 805-818Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    High precision and reliable haptic devices are highly complex products. The complexity that has to be carefully treated in the design process is largely due to the multi-criteria and conflicting character of the functional and performance requirements. These requirements include high stiffness, large work-space, high manipulability, small inertia, low friction, high transparency, as well as cost constraints. The requirements are a basis for creating and assessing design concepts. Concept evaluation relies to a large extent on a systematic usage of kinematic, dynamic, stiffness, friction, and control models. The design process can benefit from a model-based and simulation-driven approach, where one starts from an abstract top-level model that is extended via stepwise refinements and design space exploration into a detailed and integrated systems model that can be physically realized. Such an approach is presented, put in context of the V-model, and evaluated through a test case where a haptic device, based on a Stewart platform, is designed and realized. It can be concluded, based on simulation and experimental results that the performance of this deterministically optimized haptic device satisfies the stated user requirements. Experiences from this case indicate that the methodology is capable of supporting effective and efficient development of high performing haptic devices. However, more test cases are needed to further validate the presented methodology.

  • 12.
    Ahmad, Aftab
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Kjell, Andersson
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    An optimization approach towards a robust design of 6-DOF haptic devicesManuskript (preprint) (Annet vitenskapelig)
  • 13.
    Ahmad, Aftab
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Kjell, Andersson
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Model-based control strategy for 6-DOF haptic devicesManuskript (preprint) (Annet vitenskapelig)
  • 14.
    Ahmad, Aftab
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Kjell, Andersson
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Boegli, Max
    Evaluation of friction models for haptic devices2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this work different friction models are evaluated to determine how well these models are suited for performance simulation and control of a 6-DOF haptic device. The studied models include, Dahl model, LuGre model, Generalized Maxwell slip model (GMS), smooth Generalized Maxwell slip model (S-GMS) and Differential Algebraic Multistate (DAM) friction model. These models are evaluated both numerically and experimentally with an existing 6-DOF haptic device that is based on a Stewart platform. In order to evaluate how well these models compensate friction, a model-based feedback friction compensation strategy along with a PID controller were used for position fracking accuracy The accuracies of the friction compensation models are examined separately for both low-velocity and high-velocity motions of the system. To evaluate these models, we use criteria based on fidelity to predict realistic friction phenomena, easiness to implement, computational efficiency and easiness to estimate the model parameters. Experimental results show that friction compensated with GMS, S-GMS and DAA4 models give better accuracy in terms of standard deviation, Root Mean Squared Error, and maximum error between a reference and measured trajectory. Based on the criteria of fidelity, ease of implementation and ease to estimate model parameters, the S-GMS model, which represents a smooth transition between sliding and pre-sliding regime through an analytical set of differential equations, is suggested.

  • 15.
    Andersson, Kjell
    KTH, Tidigare Institutioner, Maskinkonstruktion.
    A REQUIREMENT-DRIVEN PRODUCT DEVELOPMENT PROCESS2004Inngår i: 7th Workshop on Product Structuring: Product platform Development / [ed] J. Malmqvist, 2004, s. 37-48Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Product development is often described as an iterative process of finding solutions that match specific requirements. The many dimensions of this process include time, organization, product-specific elements such as the level of abstraction and detail, and analysis to verify the product’s properties.

    Many types of software tools are used to generate and visualize the concept shape. These include CAD (computer-aided design) tools; tools to simulate and verify product properties, such as FE (finite element analysis) and MBS (multibody systems); and tools for handling product data such as PDM (product data management). This paper focus on the effective use of simulation software such as FE and MBS tools to support the process of verifying that a product meets the formulated requirements. The simulation software can be used for such things as selecting alternative solutions or as a final check or optimization of a solution concept. Its can be used even more effectively if it is supported by a framework for handling the information created during the verification process.

    This paper presents a proposal for an information framework that can support traceability and reuse of partial results created during the verification of a specific required attribute. This framework also facilitates study of the effects of changes in the specification on product properties. The framework is illustrated in a modeling and simulation scenario for a lifting unit on a wheel loader produced by Volvo CE. This scenario focus on modeling and simulation activities and how these can be supported in a question-and-answer driven process that investigates the behavior of the lifting unit. 

  • 16.
    Andersson, Kjell
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Modular simulation models as a key enabler for a question-answer driven verification process2006Inngår i: 1st Nordic Conference on Product Lifecycle Management: NordPLM'06, 2006, s. 99-110Konferansepaper (Fagfellevurdert)
  • 17.
    Andersson, Kjell
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Reality-driven virtual wheel loader operation2005Inngår i: Proceedings of Virtual Concept 2005, 2005Konferansepaper (Fagfellevurdert)
  • 18.
    Andersson, Ricky
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Marina system.
    Naval ArchitectureRICKY ANDERSSONrickya@kth.se0739-5332522015-06-2015Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    På allt senare tid har sjöfarten blivit allt mer eftertraktat och ett nödvändigt transportsätt för att frakta de saker som krävs och önskas av oss människor oavsett var på jorden man är. Det finns många olika sorters av fartyg desginade för olika ändamål som t.ex. roro-fartyg för frakt av fordon, containerfartyg för frakt av containers, bulkfartyg för frakt av olja, kol, malm, trä och passagerarfärjor för frakt och nöjesresor med människor.

    Två bulkfartyg har tagits fram för att klara av att frakta 235 000 ton järnmalm(pellets) och har en marschfart på 13,5 knop. Den låga farten gör att kostnaden för frakten kan hållas nere och ändå klara leveransmålet som är 450 000 ton pellets per månad från Narvik, Norge till New York City, USA. Fartyget har slankhetstalet 0,85, vilket nästan motsvarar en fyrkantig låda, allt för att få en stabil gång under färd. Fartyget har en längd på 333 meter och en bred på 57 meter. Motoreffekten för att driva fartyget är 17 000 kW inkluderat en säkerhetsmarginal med 15 % för extremt väder eller tidspress.

    Energibehovet i världen är stora och på grund av att de förnyelsebara energikällorna inte räcker till använder man sig av fossila bränslen. Att hitta olja och gas som är ett fossilt bränsle kräver mycket arbete, både i planering samt utrustning. En del av den olja och gas finns offshore och kräver fartyg för transportering och tömning från oljeriggarna men kan också användas för prospektering.

    Riskerna är dock väldigt stora i denna bransch och måste tas i största beaktning. Det är dyra investeringar i kampen om att hitta de naturtillgångar som finns kvar. Det har i dagsläget blivit aktuellt att undersöka och prospektera i arktiska områden som är helt outforskat, detta ställer givetvis ännu större krav på utrustning och riskerna ökar.

  • 19. Anton, Nicholas
    et al.
    Genrup, M.
    Fredriksson, C.
    Larsson, P. -I
    Erlandsson-Christiansen, Anders
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik.
    Exhaust volume dependency of turbocharger turbine design for a heavy duty otto cycle engine2017Inngår i: Proceedings of the ASME Turbo Expo: Turbomachinery Technical Conference and Exposition, GT 2017, ASME Press, 2017, Vol. 2C, artikkel-id V02CT44A015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This study is considering turbocharger turbine performance at "on-engine" conditions with respect to turbine design variables and exhaust manifold volume. The highly unsteady nature of the internal combustion engine will result in a very wide range of turbine operation, far from steady flow conditions. As most turbomachinery design work is conducted at steady state, the influence of the chosen turbine design variables on the crank-angle-resolved turbine performance will be of prime interest. In order to achieve high turbocharger efficiency with the greatest benefits for the engine, the turbine will need high efficiency at the energetic exhaust pressure pulse peak. The starting point for this paper is a target full load power curve for a heavy duty Otto-cycle engine, which will dictate an initial compressor and turbine match. Three radial turbine designs are investigated, differing with respect to efficiency characteristics, using a common compressor stage. The influence of the chosen turbine design variables considering a main contributor to unsteadiness, exhaust manifold volume, is evaluated using 1D engine simulation software. A discussion is held in conjunction with this regarding the efficiency potential of each turbine design and limitations of turbine types.

  • 20.
    Arun, Arora
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Järnvägsteknik.
    Passive Components in Active Suspension System2013Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The concept of active technology in rail vehicles has been studied theoretically and experimentally for several decades and has now reached the stage of implementation. Active Lateral Suspension (ALS) is the active technology that leads the development in active secondary suspensions if carbody tilting is disregarded.

    Active suspension systems may have an influence on running safety of the vehicle. The requirements to fulfil are related to forces between wheel and rail. The safety must be assured by the manufacturer by a safety assessment, which must be sent to the authorities before entering service. An important part of the assessment is to show that the active system, under all conditions, is part of a vehicle that runs safely on the track. The passive components in the vicinity of the active system have an important role in assuring that even a defective active system fulfils the required safety.

    This master thesis aims to set requirements on the passive suspension components for the failed ALS.

    The study has been conducted by varying various parameters of the vehicle with different running conditions and failure cases. The study highlights that the secondary lateral bumpstop is the most important parameter for the vehicle safety.

    With soft bumpstop (low stiffness) the vehicle runs within safe limits for all studied conditions, and the effect of varying other parameters, running conditions and failure cases, is marginal. For somewhat higher stiffness (medium bumpstop), the effect of other parameters plays a critical role in ensuring safe run. For hard bumpstop, the track shift forces are above the limit values, independently of the passive component settings.

    High vertical forces have been observed for certain cases with medium bumpstop, due to primary vertical bumpstop contact, which can be prevented by increasing the primary vertical damping or by increasing the vertical play. Reduction in track shift forces has been observed with the increase of primary vertical damping. The reason for the effect is not known and is proposed for further study.

  • 21.
    Asgher, Wasim
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Lättkonstruktioner.
    Effect of material grade on fatigue strength and residual stresses in high strength steel welds2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This thesis work is concerned with effect of material grade on fatigue strength of welded joints. Fatigue strength evaluation of welded joints in as welded and post weld treated condition was carried out with effective notch method. Results of peak stress method have also been compared with those of effective notch method for as welded joints. In addition, using the results of effective notch method, the effect of important weld and global geometry factors on notch stress concentration factor has been studied with 2-level design of experiment and a mathematical relation among stress concentration factor and the geometric factors has been proposed. Overall, thickness of the base plate and toe radius is found to be the most important factors determining fatigue strength of the joint.

    Welding induced residual stresses have also been predicted using 2D and 3D FEM analysis to see their effect on fatigue strength of the joints. Also, transversal residual stresses were measured using X-ray diffraction method to assess the accuracy of predicted results. Based on simulation results, effect of geometric factors on maximum value of transversal residual stress was also investigated.

  • 22.
    Ashwear, Nasseradeen
    KTH, Skolan för teknikvetenskap (SCI), Mekanik, Strukturmekanik.
    Vibration Frequencies as Status Indicators for Tensegrity Structures2014Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

     Applications of vibration structural health monitoring (VHM) techniques are increasing rapidly. This is because of the advances in sensors and instrumentation during the last decades. VHM uses the vibration properties to evaluate many civil structures during the design steps, building steps and service life.

    The stiffness and frequencies of tensegrity structures are primarily related to the level of pre-stress. The present work investigates the possibilities to use this relation in designing, constructing and evaluating the tensegrity structures.

    The first part of the  present work studies the improvement of current models for resonance frequency simulation of tensegrities by introducing the bending behaviour of all components, and by a one-way coupling between the axial force and the stiffness. From this, both local and global vibration modes are obtained. The resonance frequencies are seen as non-linearly dependent on the pre-stress level in the structure, thereby giving a basis for diagnosis of structural conditions from measured frequencies. The new aspects of tensegrity simulations are shown for simple, plane structures but the basic methods are easily used also for more complex structures.

    In the second part, the environmental temperature effects on vibration properties of tensegrity structures have been investigated, considering primarily seasonal temperature differences (uniform temperature differences). Changes in dynamic characteristics due to temperature variations were compared with the changes due to decreasing pre-tension in one of the cables. In general, it is shown that the change in structural frequencies made by temperature changes could be equivalent to the change made by damage (slacking). Different combinations of materials used and boundary conditions are also investigated. These are shown to have a significant impact on the pre-stress level and the natural frequencies of the tensegrity structures when the environment temperature is changed.

  • 23.
    Astner, Josephine
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Initiating an Internet of Things Ecosystem inPractice: A qualitative study carried out at IBM Sweden2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The Internet of Things (IoT) concludes a network of physical objects equipped withdigital technologies to interact with people and other objects. IoT brings challenges,one way for organisations to address these challenges is by business ecosystems accordingto the analogy of natures ecosystem. This study defines an IoT oriented businessecosystem as an IoT ecosystem, because of the definitions used in the market varies.The purpose of this study was to investigate the critical factors for a working IoTecosystem, as well as propose how these factors can be applied in practice, since thisis absent in the market. A customized research design was conducted for this studyto manage the 17 semi-structured interviews at IBM. The interviews were divided initerations with di↵erent themes, where the result of each iteration was the base forthe decision of the next iteration theme. The result of this study reflected severalcritical perspectives of how to create an IoT ecosystem with partnership, end-userand scalability were recurrent. The conclusion of this were six critical factors of howan organisation can initiate an IoT ecosystem anchored with a product, as well as atool of how to apply these factors in practice.

  • 24.
    Bauner, David
    et al.
    KTH, Tidigare Institutioner, Industriell ekonomi och organisation.
    Laestadius, Staffan
    KTH, Tidigare Institutioner, Industriell ekonomi och organisation.
    The Introduction of the Automotive Catalytic Converter in Chile2003Inngår i: Journal of Transport Economics and Policy, ISSN 0022-5258, E-ISSN 1754-5951, Vol. 37, nr 2, s. 157-199Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The regional Special Commission for Decontamination of Chile's capital, Santiago, was formed in 1990. The issue of regulating passenger car emissions was one of the first initiatives on the commission's agenda, empowering a group of consultants and administrators to set up a structure for the transition in legal, economic, and commercial terms. In April 1992 the first car with a catalytic converter was sold as unleaded petrol became available, and from 1 September the same year a decree required every new car in the capital regions to be equipped with a catalytic converter. Chile thus introduced the automotive catalytic converter in little more than a year. It is argued that the critical factors for this process were the effective and efficient adoption and adaptation of foreign technology, policy, and market space, Chile's common understanding of the need to reduce emissions, and prevalent strong economic growth permitting widespread car ownership and renewal.

  • 25.
    Behere, Sagar
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Inbyggda styrsystem.
    Scoop Technical Report: Year 20112011Rapport (Annet vitenskapelig)
    Abstract [en]

    This report deals with the technical solution that was implemented for the Grand Cooperative Driving Challenge (GCDC) 2011. The GCDC involved developing a system to drive a vehicle autonomously in specific situations. Some reflections on the design process are also included. The goal of the report is to make the user understand the technical solution and the motivations behind the design choices made.

  • 26.
    Behere, Sagar
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Inbyggda styrsystem.
    Liljeqvist, Björn
    EIS by Semcon.
    Towards Autonomous Architetures: An Automotive Perspective2012Rapport (Annet vitenskapelig)
    Abstract [en]

    The use of embedded computers in modern automobiles is enabling increasingly autonomous features. Electronic power train management and applications in active safety, cooperative driving and navigation show an underlying trend of the transfer of responsibilities from the human driver to a vehicle's (semi-)autonomous subsystems. The logical culmination ofthis trend would be a completely autonomous vehicle. How should existing vehicle architectures be evolved to sustain the development and growth of autonomous functions? We explore the principal problems with existing architectures, caused due to ad hoc addition of (semi-) autonomous features and argue that it is time to rethink automotive architectures from an autonomous systems perspective. We introduce a pattern that can help architects and designers to think in terms of autonomy and suggest where the application of autonomous systems thinking should begin, in the context of architecture development.

  • 27. Bengtsson, Lars
    et al.
    Dabhilkar, Mandar
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.), Industriell ekonomi och organisation (Avd.).
    Manufacturing outsourcing and its effect on plant performance-lessons for KIBS outsourcing2009Inngår i: Journal of evolutionary economics, ISSN 0936-9937, E-ISSN 1432-1386, Vol. 19, nr 2, s. 231-257Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Despite the proclaimed advantages and popularity of outsourcing manufacturing and knowledge-intensive business services, there are few and mainly contradictory studies of its short- and long-term effects. The main purpose of this paper is to analyze the way in which outsourcing manufacturing and design work relates to performance at plant level. The study is based on a large-scale survey among a representative sample of Swedish engineering plants. The results show no significant effects from outsourcing manufacturing on plant operating performance. The paper further shows that investments in technological and organizational capabilities explain the improvements of performance to a significantly higher extent than does outsourcing. The problems of additional costs and managing dependencies when applying partial outsourcing and separating interdependent key processes provide important insights to the analysis on the effects of outsourcing knowledge-intensive business services (KIBS).

  • 28.
    Bergseth, Ellen
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    On tribological design in gear tooth contacts2012Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The correct tribological design will have a considerable effect on a gear’s service life and efficiency. The purpose of this thesis is to clarify the impact of variation in the gear tooth flank tribological system on the gear contact load capacity – to increase the understanding of how surface topography and lubricant interact.

    In this thesis the variation in surface topography inherent in the manufacturing method has been shown, by experimental work and computer simulations, to be an important factor for the contact condition in the early life of gears. Surface analysis revealed that the formation and composition of surface boundary layers depends strongly on the chemical composition of the lubricant, but also on pre-existing surface boundary layers. Additionally, surface boundary layers play a major role in frictional behaviour, wear and in allowing the lubricant to react properly with the surfaces.

    Paper A presents the current ISO 6336 calculation of surface durability. A robust design approach was used to investigate the extent to which the current standard for calculation of surface durability allows for manufacturing variations and the choice of lubricant.

    Paper B investigates the extent to which a logarithmical profile modification can increase gear contact pressure robustness compared to traditional lead profiles for gears.

    Paper C compares different gear manufacturing methods and their as-manufactured (fresh unworn) surface topographies, using measured surface topographies as input to a contact simulation program.

    Paper D examines surface boundary layer formation and the corresponding wear in relation to different anti-wear additives in an environmentally adapted base oil.

    Papers E and F make use of specimens with surface topographies imitating two gear manufacturing methods (grinding and superfinishing) to be used in a twin-disc and barrel-on-disc machine respectively. The contacts are analysed by friction measurements and simulations combined with methods for surface analysis.

  • 29.
    Bergseth, Ellen
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Sosa, Mario
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Andersson, Martin
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Investigation of pitting resistance in ultra clean IQ-Steel vs commonly used conventional steel; 158Q vs 16MnCr5: Back-to-back pitting tests2015Rapport (Annet vitenskapelig)
    Abstract [en]

    KTH Machine Design has conducted pitting tests on gears made out of two different types of steel in a standard back-to-back pitting test rig (FZG). The tested gears were produced from Ovako’s IQ-Steel in grade 158Q and compared to the behaviour of a reference steel, commonly used conventional steel in grade 16MnCr5 (reference steel, RS). The test method is a mechanical test procedure generally used to determine the pitting load capacity of gear transmission lubricants, but in this study the purpose was to compare the pitting load capacity of the two steel types. The report is based on the test procedure described in FVA – Information sheet Research Project No. 371 (Practice Relevant Pitting Test) with minor changes. Time to failure and photographs of the fatigue damages are presented in this report. One gear tooth from each steel type was analysed using SEM. The results, which are based on six tests in total (three gear pairs IQ-Steel and three RS-steel), indicate that the IQ-Steel has better surface durability than the reference steel. To better understand the mechanisms involved, further tests are suggested.

  • 30. Bergsjö, D.
    et al.
    Vielhaber, M.
    Malvius, Diana
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Burr, H.
    Malmqvist, J.
    Product lifecycle management for cross-x engineering design2007Inngår i: Proceedings of ICED 2007, the 16th International Conference on Engineering Design, 2007Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper deal with the urgent problem to create integrated PLM solutions in today's European automotive industry. Two European automotive companies have been used as case companies in order to carry out these studies. Configuration management and engineering change management are two information management processes that span throughout the extended company, through engineering domains and through the product lifecycle. This makes them ideal as study objects to create new methods, and to enable PLM for cross-x engineering design. Several guidelines regarding IT system architectures for cross-x PLM are presented, e.g.: modularity, central coordination, standard communication, minimum process redundancy, and general modelling constructs.

  • 31.
    Bergsten, Andreas
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.), Industriell ekonomi och organisation (Avd.).
    Fackets kulturkris: metaforer som organixationsterapi2009Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    Union representatives today have constantly to discuss and redefine their roles, as established patterns of negotiation and decision-making changes. The Swedish model of collective bargaining and corporatist representation in government has slowly been weakened and unions seek new ways of serving the interests of their members. This study focuses on disagreements and uncertainties in groups of white-collar union representatives concerning purposes and roles.

    The dialogue seminar method, developed at the Royal Institute of Technology, is a tool for practitioners to examine the tacit knowledge that informs their work. Ideas from Ludwig Wittgenstein's later philosophy concerning rule-following and language games figures prominently in the development of this method. In four dialogue seminar series, union representatives from the Swedish white-collar union Sif (Unionen from 2008) have explored their present situation and future challenges. The lack of a common understanding in these seminars is traced to the wider organizational culture and trends in public opinion. A cultural crisis in the union is understood in Wittgenstein's terms of  'captivating pictures' – patterns of thought that remain unchallenged.

    How such pictures captivate and dictate our thinking by way of implicit analogy is further discussed in this study. Elements from psychoanalytic theory are introduced to outline a theory of organizational development based on our innate capacity for analogical thinking. Criticizing a certain naïve rationalism in current mainstream management models, a deliberate use and critique of metaphors is suggested as an organizational therapy for practitioners thus captivated. This draws attention to a vital potential in the use of dialogue, unexploited in organizational practice.

  • 32.
    Berlin, Daniel
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.), Hållbarhet och industriell dynamik.
    Engwall, Mats
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.), Industriell Management.
    Organizing ERS Projects: Implications for Demonstrations and Deployments: A Comparative Stakeholder Analysis of the Swedish ERS-Projects eRoadArlanda and eHighway E162018Rapport (Annet vitenskapelig)
    Abstract [en]

    The electric road system (ERS) receives increasing attention as a potential solution to cope with the transition to environmentally friendly heavy road transport. Moving from the initial technology development phase to the technology demonstration phase has motivated the creation of demonstration projects. Thus, ERS-project organizations have evolved.

    This report makes an inquiry into the organizing of ERS-projects. It is based on a comparative analysis of the two ongoing demonstration projects in Sweden; eRoadArlanda and eHighway E16. The study addresses what implications the current ERS demonstration projects can provide through a stakeholder assessment.

    The outcome of the study is 11 implications for the organizing of ERS demonstration and deployment projects. These are divided among the six perspectives: project leadership, electric road vehicle, electric infrastructure, funding, verification, and interest vs power.

  • 33.
    Biasetti, Jacopo
    KTH, Skolan för teknikvetenskap (SCI), Hållfasthetslära (Inst.), Biomekanik.
    Physics of blood flow in arteries and its relation to intra-luminal thrombus and atherosclerosis2013Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Vascular pathologies such as Abdominal Aortic Aneurysm (AAA) and atherosclerosis are complex vascular diseases involving biological, mechanical, and fluid-dynamical factors. This thesis follows a multidisciplinary approach and presents an integrated fluid-chemical theory of ILT growth and analyzes the shear-induced migration of red blood cells (RBCs) in large arteries with respect to hypoxia and its possible role in atherosclerosis. The concept of Vortical Structures (VSs) is employed, with which a theory of uid-chemically-driven ILT growth is formulated. The theory proposes that VSs play an important role in convecting and activating platelets in the aneurysmatic bulge. In particular, platelets are convected toward the distal aneurysm region inside vortex cores and are activated via a combination of high residence times and relatively high shear stress at the vortex boundary. After vortex breakup, platelets are free to adhere to the thrombogenic wall surface. VSs also convect thrombin, a potent procoagulant enzyme, captured in their core, through the aneurysmatic lumen and force its accumulation in the distal portion of the AAA. This framework is in line with the clinical observation that the thickest ILT is usually seen in the distal AAA region. The investigation of the fluid-dynamics in arteries led to the study of the shear-induced migration of RBCs in large vessels such as the abdominal aorta and the carotid artery. Marked RBCs migration is observed in the region of the carotid sinus and in the iliac arteries, regions prone to atherogenesis. This leads to the hypothesis that oxyhemoglobin availability can decrease in the near-wall region thus contributing to wall hypoxia, a factor implicated in atherosclerosis. The thesis proposes a new potential mechanism of ILT growth, driven by fluid and chemical stimuli, which can be used to study ILT progression over physiologically relevant timeframes and be used as a framework to test new hypotheses; the thesis also provides new insights on the oxyhemoglobin availability in the near-wall region with direct inuence on atherosclerosis.

  • 34.
    Biasetti, Jacopo
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Hållfasthetslära (Inst.), Biomekanik.
    Spazzini, Pier Giorgio
    Mechanics Division, National Institute of Metrological Research (INRiM), Turin, Italy.
    Gasser, T. Christian
    KTH, Skolan för teknikvetenskap (SCI), Hållfasthetslära (Inst.), Biomekanik.
    Shear-induced migration of red blood cells in the abdominal aorta and thecarotid bifurcation: considerations on oxygen transport2013Rapport (Annet vitenskapelig)
    Abstract [en]

    Shear-induced migration of red blood cells (RBCs) is a well known phenomenon characterizing blood flow in the small vessels (micron to mm size) of the cardiovascular system. In large vessels, like the abdominal aorta and the carotid artery (mm to cm size), the extent of this migration has not been fully elucidated. RBCs migration exerts its influence primarily on platelet concentration, oxygen transport and oxygen availability at the luminal surface; this being of primary importance in, for example, intra-luminal thrombus (ILT) growth, atherosclerosis and intima hyperplasia. Phillips’ shear-induced particle migration model coupled to the Quemada viscosity model was employed to simulate the macroscopic behavior of RBCs in four patient-specific geometries: a normal abdominal aorta, an abdominal aortic aneurysm (AAA), a normal carotid bifurcation and a stenotic carotid bifurcation. Simulations show a migration of RBCs from the near wall region with a lowering of wall hematocrit (volume fraction of RBCs) on the posterior side of the normal aorta and in the iliac arteries. A marked migration is observed on the outer wall of the carotid sinus, the inner curvature wall of the common carotid artery and in the carotid stenosis. No significant migration is observed in the AAA. The spatial and temporal patterns of wall hematocrit are correlated with the near-wall shear layer and with the secondary flow induced by the vessel curvature. The results reinforce data in literature showing a decrease in oxygen partial pressure on the inner curvature wall of the carotid sinus and, more in general, on the inner curvature wall. The lowering of wall hematocrit is postulated to induce a decrease in oxygen availability at the luminal surface through a diminished concentration of oxyhemoglobin, hence contributing, with the lowered oxygen partial pressure, to local hypoxia.

  • 35.
    Biasetti, Jacopo
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Hållfasthetslära (Inst.), Biomekanik.
    Spazzini, Pier Giorgio
    Mechanics Division, National Institute of Metrological Research, Turin, Italy.
    Swedenborg, Jesper
    Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.
    Gasser, T. Christian
    KTH, Skolan för teknikvetenskap (SCI), Hållfasthetslära (Inst.), Biomekanik.
    An Integrated Fluid-Chemical Model Toward Modeling the Formation of Intra-Luminal Thrombus in Abdominal Aortic Aneurysms2012Inngår i: Frontiers in Physiology, ISSN 1664-042X, E-ISSN 1664-042X, Vol. 3, nr 266Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Abdominal Aortic Aneurysms (AAAs) are frequently characterized by the presence of an Intra-Luminal Thrombus (ILT) known to influence their evolution biochemically and biomechanically. The ILT progression mechanism is still unclear and little is known regarding the impact of the chemical species transported by blood flow on this mechanism. Chemical agonists and antagonists of platelets activation, aggregation, and adhesion and the proteins involved in the coagulation cascade (CC) may play an important role in ILT development. Starting from this assumption, the evolution of chemical species involved in the CC, their relation to coherent vortical structures (VSs) and their possible effect on ILT evolution have been studied. To this end a fluid-chemical model that simulates the CC through a series of convection-diffusion-reaction (CDR) equations has been developed. The model involves plasma-phase and surface-bound enzymes and zymogens, and includes both plasma-phase and membrane-phase reactions. Blood is modeled as a non-Newtonian incompressible fluid. VSs convect thrombin in the domain and lead to the high concentration observed in the distal portion of the AAA. This finding is in line with the clinical observations showing that the thickest ILT is usually seen in the distal AAA region. The proposed model, due to its ability to couple the fluid and chemical domains, provides an integrated mechanochemical picture that potentially could help unveil mechanisms of ILT formation and development.

  • 36.
    Binder, Christian
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik. Scania CV AB.
    Experiments on Heat Transfer During Diesel Combustion Using Optical Methods2019Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Transportation is a crucial part of modern societies. This includes their economies. Trade and the transportation of goods have a great influence on prosperity. Nevertheless, the transportation sector with road transport in particular is heavily dependent on fossil fuels and emits a significant amount of greenhouse gases. One approach to mitigate the negative environmental impact of road transport is to increase the efficiency of its most common propulsion system, that is the internal combustion engine. Due to its dominant role in the road freight transportation sector, this thesis directs its attention to heavy-duty diesel engines. In-cylinder heat losses are one of the main factors that reduce engine efficiency. Therefore, the objective of this thesis is to gain a better understanding of the processes that influence in-cylinder heat losses by resolving them in time and space using optical methods. In diesel engines, most of the in-cylinder heat losses are transferred to the piston. As a result, this thesis focuses specifically on that component.

    In this research project, the task to determine in-cylinder heat losses to the piston in heavy-duty diesel engines is divided into two parts. The most important part consists of fast surface temperature measurements on the piston using phosphor thermometry. The heat transfer coefficient inside the piston cooling gallery defines an additional steady-state boundary condition.

    The work presented in this thesis includes therefore efforts to improve in-cylinder surface temperature measurements and an assessment of their accuracy and precision. Furthermore, it comprises of experimental results from measurements on steel pistons and a piston with an insulating thermal barrier coating. Results reveal spatial differences of the heat transfer during diesel combustion. Measurements at the impingement point indicate a strong influence of flame impingement on local heat transfer. A correlation is detected between heat transfer and cycle-to-cycle variations of flame impingement.

    The thesis also reports efforts to determine the heat transfer coefficient inside the piston cooling gallery. Using an infrared camera a method is presented to spatially resolve convective heat transfer inside this cooling channel.

  • 37.
    Binder, Christian
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik. Scania CV AB.
    Henrik, Feuk
    Lund University.
    Richter, Mattias
    Lund University.
    Phosphor Thermometry for In-Cylinder Surface Temperature Measurements in Diesel Engines2019Inngår i: Measurement science and technology, ISSN 0957-0233, E-ISSN 1361-6501Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    Surface temperature measurements in technically relevant applications can be very  hallenging and yet of great importance. Phosphor thermometry is a temperature measurement technique that has previously been employed in technically relevant applications to obtain surface temperature. The technique is based on temperature-dependent changes in a phosphor’s luminescence. To improve the accuracy and precision of temperature measurements with this technique, the present study considers, by way of example, the impact of conditions inside the cylinder of a diesel engine on decay time based phosphor thermometry. After an initial, general assessment of the effect of prevailing measurement conditions, this research investigates errors caused by soot luminosity, extinction, signal trapping and changes of phosphors’ luminescence properties due to exposure to the harsh environment. Furthermore, preferable properties of phosphors which are suitable for in-cylinder temperature measurements are discussed. 16 phosphors are evaluated, including four which – to the authors’ knowledge –have previously not been used in thermometry. Results indicate that errors due to photocathode bleaching, extinction, signal trapping and changes of luminescence properties may cause an erroneous temperature evaluation with temperature errors in the order of serval tens of Kelvin.

  • 38.
    Birkie, Seyoum Eshetu
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Hållbar produktionsutveckling (ML).
    Bellgran, Monica
    KTH, Skolan för industriell teknik och management (ITM), Hållbar produktionsutveckling (ML).
    Feldmann, Andreas
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.).
    Managing manufacturing footprint decisions for better sustainability2019Konferansepaper (Fagfellevurdert)
  • 39. Björklund, Glenn
    et al.
    Swarén, Mikael
    KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Låt underlaget bestämma löpsteget2014Inngår i: Svensk Idrottsforskning: Organ för Centrum för Idrottsforskning, ISSN 1103-4629, nr 4, s. 8-11Artikkel i tidsskrift (Annet vitenskapelig)
  • 40.
    Brodin, Felix
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Marina system.
    Kandidatexamensarbete Marina system KTH 20152015Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Denna rapport innehåller både en fartygsprojektering och en undersökning huruvida man med hjälp av kraftdrakar kan minska bränsleförbrukningen på oceangående motortrålare. Fartygsprojekteringen gäller ett RoRo-fartyg som ska frakta 300 lastbilar, inklusive passagerare och trailers varje vecka till Åbo respektive till Oxelösund, medan den sistnämnda undersökningen är gjord på en Diesel Duck 462 - en typ av fritidsbåt för helt andra ändamål. Syftena med dessa undersökningar skiljer sig så pass mycket att de tilldelas varsina separata abstrakt.

    I fartygsprojekteringen ingår utöver ett designförslag på själva fartyget även ett designförslag på en tillhörande propeller. De två metoderna som tillämpas för denna propellermodellering förklaras separat i ett Propellerappendix i bilaga 3, där även tillhörande Matlab-koder återfinnes. Som bilaga finns även en kort essä om sjöfart i stort – se bilaga 6.

  • 41.
    Börjeson, Simon
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Marina system.
    Ghawi, Philippe
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Marina system.
    Energieffektiv Linjesjöfart Till Och Från Gotland2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [sv]

    The ferry traffic to Gotland is essential for the island’s ability to live and develop. Yearly, it transports 1,6 million passengers, 500 000 personal vehicles and 750 000 lane meters of freight with four Ro-Pax ferries. The traffic is controlled and subsidized by the Swedish government since 1971 in order to guarantee the inhabitants and industry of Gotland a satisfactory transportation service. As a consequence of the past decades increased traffic quality, mainly due to a decrease in crossing times, the traffic’s environmental impact and costs has also increased.

    The Master Thesis proposes a new energy efficient traffic arrangement that satisfies the users’ preferences in the same extent as today. The report presents the proposed traffic arrangement’s resulting energy demand and approximate costs, its ships, their routes, speeds and daily capacity. The report also presents the self-developed methodology which is used to evaluate and hence generate the final traffic arrangement. The methodology is called E-fleet in its programmed format.

    The Master Thesis, Energy Efficient Ferry Traffic to and from Gotland, shows that the Gotland Ferry Traffic can, with conventional technology, operate with 49 % less carbon dioxide emissions and with 200 million kronor less in fuel costs than today, without decreasing the traffic quality. The economical and environmental savings are achieved through a well planned traffic with suitable tonnage on appropriate routes.

  • 42.
    Börjesson, Fredrik
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.). odular Management USA, Inc., Bloomington, MN, United States .
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Modularization of novel machines: motives, means and opportunities2010Inngår i: Proceedings of NordDesign 2010, the 8th International NordDesign Conference: Chalmers University of Technology,Gothenburg, Sweden, August 25-27, 2010, 2010, s. 435-444Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Modularization approaches are often used to restructure mature products with known technical content, but not to assist new development of products with a high innovation content or soft interactive requirements. This paper investigates if various clustering techniques can be used to identify module candidates in matrix representations of evolving product properties, including interactive properties, and component architectures. The proposed approach is tested on the hybrid drive train of a novel forwarder. Forwarders are used in the forestry industry to transport logs from the felling area to a landing area close to a road accessible by trucks. Continuous efficiency improvements, new emission requirements, and the need to configure machine for different applications stresses the need for a modular product architecture.

  • 43.
    Carlqvist, Per
    et al.
    Micronic Laser Systems AB, Sweden .
    Brattström, Patrik
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Mekatronik.
    During, Carl
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Mekatronik.
    Optimization of Active Vibration Control of a Laser Pattern Generator in Micro Lithography2010Inngår i: Proceedings of the 10th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2010, euspen , 2010, Vol. 1, s. 491-494Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The extreme precision requirements in semiconductor manufacturing drive the need for an active vibration isolation system in a laser pattern generator. Optimization has been performed and evaluated in a model using a high level programming tool [1]. The areas of optimization were 1) Decoupling strategies for decentralized control and 2) Improved feed forward control. Only a limited description of the model itself is given here. More about the model is presented in [2] and [3].

  • 44. Carlqvist, Per
    et al.
    Ivone, Davide
    Politechnico di Milano, Italy .
    During, Carl
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Mekatronik.
    Wikander, Jan
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Mekatronik.
    Benchmark of High Level Programming: Pilot Case Vibration Control2009Inngår i: Proceedings of the 9th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2009 / [ed] H. Van Brussel, E. Brinksmeier, H. Spaan, T. Burke, 2009, Vol. 1, s. 361-364Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The advancement of technology of laser pattern generators needs to meet demands of the rapid product development pace in the display and semiconductor markets. A hypothesis is that efficiency in the development process of complex systems can be improved by introducing a higher level programming approach. This will make a model and simulation based development (MBD) strategy more easy to adapt leading to 1) higher technical performance at shorter development time from idea to product introduction phase, 2) lower cost of goods, 3) shorter production-, installations- & upgrade time and 4) possibility of very efficient field support & service, etc. The success of an MBD approach is dependent on the simulation software capability to express the behavior of a real system. Consequently, as a first step towards an MBD approach, the investigation covers a pilot-study where results from simulations are compared to an existing controlled system.

  • 45.
    Carlsson, Carl-Anders
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Marina system.
    Naval Architecture Kandidatexamensarbete2015Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Sjofart

    This chapter is an essay that describes the role of shipping from a historical point of view as well as the impact of shipping on society.

    Fartygsprojektering

    This chapter is a projection of a ship that can transport 120 000 tonnes of crude oil from Venezuela to Seattle in the United states. The result of this projection is two ship that is 265 meters long and 40 meters wide that transport 80 000 tonnes of oil to Seattle before returning to Venezuela. This journey will take 40 days with a speed of 13 knots. The ship fufillls all regulations that it needs to fufilll.

    Fordjupning

    This chapter focuses on a request for information issued by Stockholm county council concerning public transport on water. The routes covered in this report are those planned for Malaren. These routes are at the time for writing of this report non existing. From this RFI, the authors of this chapter have developed three different ships, two catamarans and one single hull vessel, that carry between 70 and 150 persons. The catamarans have the dimensions of 10 x 25 meters with four or six doors each. The doors are 2,5 meters wide, which allow for fast embarkment and disembarkment. The single hull vessel is 20 x 6 meters and has only one door. The catamarans are partially driven by electricity, which is in line with Stockholm county council's vision of a vehicle fleet driven by 90% renewable fuels. To accommodate these ships in port, a pier concept has also been conceived. This pier is a floating one, with automatic gang planks which hold theship in place, when in port.

  • 46.
    Cederlund, Birger
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Marina system.
    Product Development; Water-cleaning Device for the Boat Wash, Miniwash2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Antifouling paints are a big enemy to the marine ecosystem.  Many tons of copper,  zinc  and  other  harmful  substances  are  released  into  the  environment each year, in Sweden alone. 

    This study concentrates on the mechanical antifouling method, using boat washes instead, which is a more sustainable alternative. It comes with reduced fuel consumption, increased speed, and moreover, no need for grinding and painting the hull each year. 

    As long as paint residues remain on hulls, but the boat washes are used instead of new paint, it is desired to collect what is scraped of the hulls. By collecting paint flakes and particles accumulated in organic material, the environmental impact is reduced further.  The scope of this Master’s thesis is to design a collection device for the portable boat wash Miniwash. 

    A collection device with a cleaning system was developed using the pump effect from the brushes along with an extra pump to press the contaminated water through a bag filter taking most of the particles. One can expect as much as 70% of   the   harmful   particles   can   be   taken   care   of,   according   to   the   filter manufacturer, based on given conditions and filter bag pore sizes. By always having a  flow of 8  cubic meters per hour through the cleaning system, it  is assumed  that  not  much  of  the  cleaning  water  will  escape,  not  passing  through The bag filter.

  • 47.
    CHAKKALAKKAL, JOSEPH JUNIOR
    KTH, Skolan för industriell teknik och management (ITM), Industriell produktion, Maskin- och processteknologi.
    Design of a weight optimized casted ADI component using topology and shape optimization2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Structural Optimization techniques are widely used in product development process in ‘modern industry’ to generate optimal designs with only sufficient material to serve the purpose of the component. In conventional design problems, the design process usually generates overdesigned components with excess material and weight. This will in turn increase the life time cost of machines, both in terms material wastage and expense of usage. The thesis “Design of a weight optimized casted ADI component using topology and shape optimization” deals with redesigning a component from a welded steel plate structure into a castable design for reduced manufacturing cost and weight reduction. The component “Drill Steel Support” mounted in front of the drilling boom of a Face Drilling Machine is redesigned during this work. The main objective of the thesis is to provide an alternative design with lower weight that can be mounted on the existing machine layout without any changes in the mounting interfaces. This thesis report covers in detail procedure followed for attaining the weight reduction of the “Drill Steel Support” and presents the results and methodology which is based on both topology and shape optimization.

  • 48. Chen, Li
    et al.
    Song, Zhijie
    Feng, Lei
    Design and Manufacturing Integration Laboratory, Department of Mechanical and Industrial Engineering, The University of Toronto, 5 King's College Road, Toronto, Ont., Canada M5S 3G8.
    Internet-Enabled Real-Time Collaborative Assembly Modeling via An e-Assembly System: Status and Promise2004Inngår i: Computer-Aided Design, ISSN 0010-4485, E-ISSN 1879-2685, Vol. 36, nr 9, s. 835-847Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Collaborative CAD systems enabling collaboration in computer-aided design processes among distributed designers are gaining more and more attention. Yet, such systems, especially in support of collaborative assembly modeling, are hardly achievable. Targeting this gap, this paper addresses an Internet-enabled real-time collaborative assembly modeling system, named e-Assembly. This emerging system allows a group of geographically dispersed designers to jointly build an assembly model in real time over the Internet. In particular, this paper proposes a new assembly representation, called Collaborative Assembly Representation, for Internet-based collaborative assembly modeling. Also, collaborative assembly constraint satisfaction is addressed based on three coordination rules embedded in e-Assembly. Furthermore, the system architecture and realization of e-Assembly are provided. Finally, a prototypic implementation of e-Assembly is presented for demonstration and discussion.

  • 49.
    Clausi, Donato
    et al.
    KULeuven.
    Gradin, Henrik
    KTH, Skolan för elektro- och systemteknik (EES), Mikrosystemteknik (Bytt namn 20121201).
    Peirs, Jan
    KULeuven.
    Braun, Stefan
    Silex Microsystems AB, Järfälla, Sweden.
    Donose, Radu
    KULeuven.
    Stemme, Göran
    KTH, Skolan för elektro- och systemteknik (EES), Mikrosystemteknik (Bytt namn 20121201).
    van der Wijngaart, Wouter
    KTH, Skolan för elektro- och systemteknik (EES), Mikrosystemteknik (Bytt namn 20121201).
    Reynaerts, Dominiek
    KULeuven.
    Reliability of Silicon Spring-biased SMA Microactuators2012Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    This paper reports on the performance of Joule-heated shape memory alloy (SMA) microactuators on silicon MEMS.The actuators consist of pre-strained SMA wires connected to micromachined silicon structures by electroplatedfixtures. Response of the actuators upon long term cycling by electrical heating is evaluated. Measurements on a 4.5x 1.6 mm2 footprint device demonstrated excellent stability of the actuator, without any loss of performance over150·103 cycles. These actuators are potentially suited for industrial applications with stringent demands on actuationperformance, reliability, and cost.

  • 50.
    CLEMEDTSON, JOSEFIN
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    PÄÄJÄRVI, EMELIE
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    To Plant and Grow Innovation: Steering Support for Innovation Processes in Medium Sized Companies2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Being innovative and environmentally sustainable can help companies to achieve success. Depending on the size of the company it can be achieved in different ways. When conducting innovation projects, the level of formal steering support might differ, especially if sustainability wants to be achieved. This thesis aims to answer the question how the need of ensuring the firm’s vision of being environmentally sustainable and use it as a marketing advantage affect the need of formal steering support in innovation projects in medium sized enterprises. Until today research have not addressed this question in a sufficient manner whereas focus has been on “SME’s” (Small and Medium sized Enterprises), small or large companies. Large companies need rather formal processes while smaller companies can be more informal and flexible. This thesis takes the perspective of the medium sized company and investigates their specific needs. A variety of innovation projects have been studied at a medium sized company and insights from it has been combined with literature on innovation processes to find the right balance of formality. The conclusion being drawn is that formality is needed especially in the beginning and in the end of an innovation project for a medium sized company if sustainability wants to be achieved and used as a marketing advantage.

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