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  • 1. Aagaard, A.
    et al.
    Ritzén, Sofia
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development. KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    The critical aspects of co-creating and co-capturing sustainable value in service business models2019In: Creativity and Innovation Management, ISSN 0963-1690, E-ISSN 1467-8691Article in journal (Refereed)
    Abstract [en]

    Numerous researchers and practitioners emphasize the potential to create value through sustainable business models (SBMs). However, little attention has been paid to how sustainable value is proposed, created, delivered, and captured in the organization, and how customers perceive sustainable value in service. The aim of this paper is to explore this research gap empirically through a case study of sustainable value (co-)creation through SBMs of sustainable service innovations as experienced among two hotels' managers, employees and customers. The contributions of the study relate to the development of SBMs in service, where the value processes happen simultaneously and where the element value perception has to be added to the extant SBM literature, which is closely related to the creation and delivery of physical goods as in product-oriented industries. The study also contributes through the dual perspective (providers and customers) on sustainable value proposition, value creation and value capture. The findings reveal different key aspects in creating and capturing sustainable value through SBMs and sustainable service innovation. The managerial implications for creating and implementing SBM in service stress the need for employee engagement, customer involvement and targeted and personal communication educating internal and external sustainability ambassadors.

  • 2.
    Abdo, Nawar
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Modularization and evaluation of vehicle’s electrical system2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Modularization is a strategy used by many companies, to help them provide their customers with a high variety of customized products efficiently. This is done through the customization of different independent modules, which are connected by standardized interfaces that are shared throughoutthe entire module variety.

    Scania, being one of the large companies that provide modular products, has been successfully improving their modularization concepts for many years, and is one of the most iconic companies when it comes to modularization of buses, trucks and engines. But with the increasing need ofelectronics integrated in the vehicles, it is becoming more and more important to modularize the electrical system.

    There is currently an existing, modularized, product architecture for the electrical system, and Scania wants to know how well modularized it is, as there is no unified way that indicates what is considered to be the better solution.To analyze the current state of the electrical system, a systematic method of modularization was used, which would help answer three important questions: Are the modules well defined? Is there a way to systematically compare alternative solutions? What criteria are more important to focus on?

    Since there is no unified way of modularization, many modularization methods have been created, and each one has been optimized for a certain purpose.

    This project compares three different modularization methods and then uses one of the methods which is deemed to be the preferred method to help provide the answers that the company seeks when investigating the modularity of the electrical system.

    As the electrical system is very complex, and the project has limited amount of resources, it was decided to choose one of the control units as an example, which was the APS (air processing system).

    The literature study showed that the most rewarding method to use was the MFD (Module Function Deployment), as it provides more information about the product and what criteria the company should focus on. It was then decided to use the relevant steps in MFD to analyze the state of the APS as an example of how this method works.

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  • 3.
    Adamsson, Niklas
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Interdisciplinary integration in complex product development: managerial implications of embedding software in manufactured goods2007Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    Incorporating electronics and software systems into manufactured goods is becoming very common in manufacturing companies. New technical functions, increased flexibility, and compensation for mechanical design weaknesses are some key drivers of this technological change in our everyday products. The automotive industry exemplifies this trend, since approximately 80–90% of new functions in cars are based on electronics and software, and it is expected that at least a third of the total cost of a car will eventually be accounted for by electronics and software. However, one of the main downsides of this technological trend is the increasing number of quality issues related to these new technologies, something usually claimed to be a result of the increased product development complexity.

    Previous research into product development management has mainly concentrated on either physical products or software systems, but not concurrently on both. Additionally, much of the research has concentrated on issues of integrating marketing, R&D, and manufacturing in these companies, and has treated the engineering disciplines in R&D as a homogenous group. Motivated by this change in technology content and the lack of research into complex product development and especially into integration between engineering disciplines, the present work investigates how to increase operational performance in multidisciplinary engineering organizations. This work has especially focused on interdisciplinary integration and the feasibility of various so-called integration mechanisms, such as building common physical facilities, job rotation programs, the implementation and use of information and communications technology, and computer-aided engineering tools.

    Both qualitative and quantitative research has been performed, involving 11 different companies and over 300 respondents. Supported by the present findings, it is demonstrated that interdisciplinary integration is a crucial factor to consider, and it is concluded that certain integration mechanisms stand out as more important than others. Organizational structure, work procedures and methods, training, social systems, and computer-aided engineering were the five types of mechanisms that displayed the greatest potential for improvement.

    It is further concluded that the ability to successfully match the body of practices to current products is essential, since there is a high risk of current practices becoming out-dated with respect to the technology content. Furthermore, inadequate identification of or managerial ability to establish the currently most important interfaces complicate the choice of trade-offs between various technologies that are found to be essential to cope with the inherent dynamic complexity. The organizational powerbase is often re-positioned in the studied organizations, and the loss of decisive power can result in a demoralizing ignorance of newly established disciplines and their design practices. Additionally, rigid structures and counterproductive traditions can reduce the potential gains accruing from new boundary-spanning innovations, so organizational responsibilities and mandates must be declared unambiguously, in many cases differently from how they have been in the past.

    Based on these conclusions, it is suggested that managers in organizations like those studied must be able to do the following: cultivate software knowledge in all parts and levels of the product development organization; reassess their recruitment strategies; organize for interdisciplinary collaboration; articulate and communicate the technology fusion strategy to all disciplines; and realize and disseminate the fact that product launches do not only concern manufacturability.

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  • 4.
    Adamsson, Niklas
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Management of mechatronics engineering: reflections and propositions2005In: Proceedings of 12th International Product Development ManagementConference, vol. 1, 2005, Vol. 1(3), p. 35-48Conference paper (Refereed)
  • 5.
    Adamsson, Niklas
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Mechatronics engineering: New requirements on cross-functional integration2005Licentiate thesis, comprehensive summary (Other scientific)
    Abstract [en]

    Several industrial sectors experience an increased reliance on mechatronic systems as electronics and software are being embedded into the traditional mechanical systems of these industries. Important challenges within mechatronics engineering comes from management of multi-disciplinary development project teams and the highly complex scope of problems, which in turn require extensive coordination and integration, both in terms of technical and organisational matters.

    The concept of cross-functional integration in product development research has in previous research mainly addressed integration of the functions marketing, R&D, and manufacturing, and whereas the present thesis is delimited to include only the R&D organization and the functions and engineering disciplines within such an organization.

    The purpose with thesis has been to investigate mechatronics engineering in order to understand and explain how co-operation, integration, and knowledge sharing between engineering disciplines can be supported.

    This research has been realized by empirical studies in mechatronic development settings in engineering companies, but also by taking part in industrial and academic research projects that develop and study computer-aided mechatronics engineering.

    Findings presented in this thesis show that mechatronics is a matter of integration at three organizational levels where the most substantial needs are found to be at the team-level and the individual level. Furthermore, it is identified that to be able to succeed in mechatronics engineering, managers and engineers must look beyond disciplinary needs. Subsequently, both teamwork and competence management become key issues for management of mechatronics engineering. Finally, computer-supported and model-based development of mechatronics show great potential for successful integration of engineering disciplines, even though such technological aids are still rather immature and needs further research and development. A tentative analysis model of organizational integration for mechatronics engineering is also presented and discussed in this thesis.

    Based on the presented findings, it is concluded that companies incorporating electronics and software in their mechanical products must effectively manage software and electronics development of these embedded systems. Despite the focus on cross-functional integration in engineering companies, this thesis shows examples of inadequate integration of software and electronics engineering with mechanical integration in organisations dominated by the latter.

    Future research studies are needed to investigate the relation between factors influencing the need for organizational integration and potential integration mechanisms. To further understand mechatronics engineering it is important to look deeper into research issues such as changed conditions for the engineering profession implied by multidisciplinary settings, social systems supporting integration of disciplines, changed work conditions due to implementation of technological aids for model-based system development, relationship between product and organizational complexity, organizational designs supporting integration of engineering disciplines, and cross-disciplinary training of highly specialized engineers.

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    FULLTEXT01
  • 6.
    Adamsson, Niklas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Malvius, Diana
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Formal and informal roles in complex product development2005In: 2005 IEEE International Engineering Management Conference, Vols 1 and 2, 2005, p. 559-563Conference paper (Refereed)
    Abstract [en]

    This paper illustrates the importance of well-articulated and demarcated roles in complex product development settings. In order to support interdisciplinary knowledge and information sharing formally assigned roles in an organization can be an effective facilitator. It is argued that without comprehensive technical knowledge it is difficult for individuals to identify the relevance and distinctiveness of technical and administrative information.

  • 7.
    Adamsson, Niklas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Zika-Viktorsson, Annika
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Challenges and outlooks for software and electrical engineering in traditional mechanical engineering companies: an investigation into workforce implications2006Article in journal (Other academic)
  • 8.
    Adamsson, Niklas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Zika-Viktorsson, Annika
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Multidisciplinary product development: - a case study of mechatronics enineeringArticle in journal (Other academic)
  • 9.
    Adamsson, Niklas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Zika-Viktorsson, Annika
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    The relative effectiveness of different mechanisms for integrating engineering disciplines in complex product development2007Article in journal (Other academic)
  • 10.
    Adamsson, Niklas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Zika-Viktorsson, Annika
    Understanding the importance of interdisciplinary integration in complex product development2007Report (Other academic)
  • 11.
    Afsharian, Reza
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Theodoropoulos, Antonios
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Modular friction test rig for measuring torque and tension in threaded fasteners2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This report describes the development of a modular friction test rig for threaded fasteners. This device can measure the shank torque and the clamp force during the tightening of threaded bolts, with a size of M3-M14 and clamp length of 30-160mm. The design allows the use of several load and torque cells and the range is up to 100kN clamp load and 200Nm applied torque. The test rig will be used for research purposes by Atlas Copco to determine the frictional characteristics in tightening and will allow the experiments on bolts with several materials, coatings and surface finishes. This report concludes to a design proposal evaluated with analytical methods and a prototype 3D model that demonstrate the working principle of the test rig. The measurements are taken from custom-made sensors that are developed with high standards, are easily interchangeable and can be calibrated individually. In addition, a device is developed to allow the user to change the stiffness of the joint. Finally, a future recommendation is made to allow the measurement of the under-head torque. This proposal is a breakthrough compared to other test rigs, and will assist in verifying the friction measurements and having high precision results.

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  • 12.
    Aftab, Ahmad
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Andersson, Kjell
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Khan, Suleman
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    A stiffness modeling methodology for simulation-driven design of haptic devices2014In: Engineering with Computers, ISSN 0177-0667, E-ISSN 1435-5663, Vol. 30, no 1, p. 125-141Article in journal (Refereed)
    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.

  • 13.
    Aftab, Ahmad
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Khan, Suleman
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Andersson, Kjell
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Kinematics and Dynamics of a novel 6-DoF TAU Haptic Device2011In: Proceedings of the 2011 IEEE International Conference on MechatronicsInternational Conference on Mechatronics, April 13-15, 2011, Istanbul, Turkey, IEEE conference proceedings, 2011, p. 719-724Conference paper (Refereed)
    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.

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  • 14.
    Agrell, Fredrik
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Control of HCCI by aid of Variable Valve Timings with Specialization in Usage of a Non-Linear Quasi-Static Compensation2006Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    This doctoral thesis is about controlling the combustion timing of the combustion concept Homogeneous Charge Compression Ignition, HCCI, by means of variable valve timings.

    The HCCI research usually is regarded to have started in Japan during the later part of the 1970´s. The world of HCCI has since grown and HCCI is of today researched worldwide. Of particular interest from a Swedish point of view is that Lund Institute of Technology has emerged as one of the world leading HCCI laboratories.

    The idea with HCCI is to combine the Otto and Diesel engine. As in an Otto engine the charge is premixed but as in a Diesel engine the operation is unthrottled and the compression heat causes the ignition. The combustion that follows the ignition takes place homogeneously and overall lean. The result is ultra low NOx and particulate emissions combined with high total efficiency. A difficulty with the HCCI-concept is that it only works in a narrow area and that there is no direct way to control the Start Of Combustion, SOC. Out of this follows that timing/phasing of the combustion is one of the main difficulties with HCCI combustion concepts. This is particularly emphasized during transient operation and calls for feedback control of the combustion timing.

    This work investigates one method, the variable valve timing, to achieve feedback control of the combustion phasing. From the work it can be concluded that the variable valve timing can control the combustion phasing during engine transients. In order to improve the performance a non-linear compensation from ignition delay to valve timings has been suggested, incorporated in a control structure and tested in engine test. The engine test has been performed in a single cylinder engine based on a Scania truck engine. The speed range from 500 to 1750 rpm and the load range 1.26 and 10.5 bar of netIMEP has been covered with fair transient performance.

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  • 15.
    Agrell, Fredrik
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Ångström, Hans-Erik
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Eriksson, Bengt
    Wikander, Jan
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Linderyd, Johan
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Control of HCCI During Engine Transients by aid of Variable Valve Timings Through the use of Model Based Non-Linear Compensation2005In: SAE transactions, ISSN 0096-736X, Vol. 114, no 3, p. 296-310Article in journal (Refereed)
    Abstract [en]

    One of the main challenges with the Homogeneous Charge Compression Ignition, HCCI, combustion system is to control the Start Of Combustion, SOC, for varying load and external conditions. A method to achieve this on a cycle-by-cycle basis is to vary the valve timing based on a feedback signal from the SOC of previous cycles. The control can be achieved with two basic valve-timing strategies named the Overlap- and the IVC-method. The Overlap-method works by trapping of residuals while the IVC-method affects the effective compression ratio. In an earlier paper it has been shown that if the two methods are incorporated into one controller, SOC can be controlled in a relatively large operating window although the transient performance was not sufficient. The reason is that the simple PI-controller cannot be made fast enough to cope with the transients without magnifying the cycle-to-cycle variations of the combustion into instability. In this work a model based control system that features a non-linear compensation, based on the inverse of the non-linear function from valve timings to ignition delay, is suggested and evaluated. The results show good transient performance. Control performance from engine tests is reported. A combined engine and control simulation system is used for the development of the control strategies. The simulations are accomplished with a commercial cycle simulation code linked with a commercial control simulation code. The simulations are iteratively verified against engine test data. Engine tests are conducted on a single cylinder engine equipped with a hydraulic valve system.

  • 16.
    Agrell, Fredrik
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Ångström, Hans-Erik
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Eriksson, Bengt
    Wikander, Jan
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Linderyd, Johan
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Practical Modeling of HCCI for Combustion Timing Control and Results from Engine Test2005In: KTH Internal Combustion Engine Report MFM, Vol. 162Article, review/survey (Refereed)
  • 17.
    Agrell, Fredrik
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Ångström, Hans-Erik
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Eriksson, Bengt
    Wikander, Jan
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Linderyd, Johan
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Transient Control of HCCI Combustion by aid of Variable Valve Timing Through the use of a Engine State Corrected CA50-Controller Combined with an In-Cylinder State Estimator Estimating Lambda2005Conference paper (Refereed)
    Abstract [en]

    One of the main challenges with the Homogeneous Charge Compression Ignition, HCCI, combustion system is to control the Start Of Combustion, SOC, for varying load and external conditions. A method to achieve this on a cycle-by-cycle basis is to vary the valve timing based on a feedback signal from the SOC of previous cycles. The control can be achieved with two basic valve-timing strategies named the Overlap- and the IVC-method. The Overlap-method works by trapping of residuals while the IVC-method affects the effective compression ratio

  • 18.
    Ahmad, Aftab
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Effective development of haptic devices using a model-based and simulation-driven design approach2014Doctoral thesis, comprehensive summary (Other academic)
    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.

     

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    Thesis
  • 19.
    Ahmad, Aftab
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Andersson, Kjell
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    An approach to stiffness analysis methodology for haptic devices2011In: 2011 3rd International Congress on Ultra Modern Telecommunications and Control Systems and Workshops (ICUMT), IEEE conference proceedings, 2011, , p. 8p. 1-8Conference paper (Refereed)
    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.

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  • 20.
    Ahmad, Aftab
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Kjell, Andersson
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    A model-based and simulation-driven methodology for design of haptic devices2014In: Mechatronics (Oxford), ISSN 0957-4158, E-ISSN 1873-4006, Vol. 24, no 7, p. 805-818Article in journal (Refereed)
    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.

  • 21.
    Ahmad, Aftab
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Kjell, Andersson
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    An optimization approach towards a robust design of 6-DOF haptic devicesManuscript (preprint) (Other academic)
  • 22.
    Ahmad, Aftab
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Kjell, Andersson
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Model-based control strategy for 6-DOF haptic devicesManuscript (preprint) (Other academic)
  • 23.
    Ahmad, Aftab
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Kjell, Andersson
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Boegli, Max
    Evaluation of friction models for haptic devices2013Conference paper (Refereed)
    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.

  • 24.
    Alemani, Mattia
    et al.
    KTH.
    Wahlström, Jens
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.). KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements. KTH, School of Industrial Engineering and Management (ITM), Applied Mechanical Engineering (KTH Södertälje). KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Tribologi.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Tribologi.
    On the influence of car brake system parameters on particulate matter emissions2018In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 396, p. 67-74Article in journal (Refereed)
    Abstract [en]

    The influence of car brake system parameters on particulate matter emissions was investigated using a pin-on-disc tribometer. Samples from a low-steel friction material and a cast iron disc were tested for different sliding velocities, nominal contact pressures and frictional powers. Disc temperatures were also measured. Their impact on total concentration, size distribution, particle coefficient and transition temperature was analysed. Results show that frictional power is the most significant brake system parameter. However, temperature, as a response parameter, is the most influential, inducing a shift towards the ultrafine particulate fraction and raising emissions. A transition temperature, independent of the system parameters, was identified.

  • 25.
    Amann, Daniel
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Kihlander, Ingrid
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.). KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Magnusson, Mats
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development. KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Product Innovation Technology.
    Affordability Aspects in the Development of Defence Equipment: Case Studies of Concept Generation in the Defence Industry2020In: Defence and Peace Economics, ISSN 1024-2694, E-ISSN 1476-8267Article in journal (Refereed)
    Abstract [en]

    Cost escalation for many complex defence equipment is arguably not sustainable. Customer driven requirements have led to an exponential increase in costs by pushing frontiers of technology to support primarily incremental improvements of traditional equipment concepts. Accordingly, affordability has become a more discussed subject in defence acquisition. This paper addresses the process of generating complex defence equipment concepts. The purpose is to explore how affordability is managed in that process and to identify possible leads to how an unsustainable cost escalation for this type of equipment can be curbed. This is done by studying two cases of concept generation of future combat air equipment systems from a company process perspective. This applied micro perspective on cost escalation showed that none of the concepts generated in these two cases were assessed to curb the cost escalation. Further, the innovation model for the generated concepts, with only one notable exception, was incremental. Nevertheless, the empirical observations from these two cases offer leads on how to potentially foster a more innovative and affordability-oriented concept generation process for future defence equipment, as well as indicating avenues for future research.

  • 26.
    Amann, Daniel
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development. Department of Military Studies, Swedish Defence University.
    Kihlander, Ingrid
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.). KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Magnusson, Mats
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development. KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Product Innovation Technology.
    Affordability Management And Its Influence On Concept Development2018Conference paper (Refereed)
  • 27.
    Amann, Daniel
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Kihlander, Ingrid
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.). KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Magnusson, Mats
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development. KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Product Innovation Technology.
    DISRUPTIVE INNOVATION BARRIERS: EXPLORING VALUE NETWORK INERTIA IN COMPLEX LOW-VOLUME PRODUCTS2019Conference paper (Refereed)
  • 28.
    Amann, Daniel
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development. Department of Military Studies, Swedish Defence University, Stockholm, Sweden.
    Kihlander, Ingrid
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.). KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development. RISE Research Institutes of Sweden.
    Magnusson, Mats
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development. KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Product Innovation Technology.
    Managing affordability in concept development of complex product systems (CoPS)2021In: Technology Analysis & Strategic Management, ISSN 0953-7325, E-ISSN 1465-3990Article in journal (Refereed)
    Abstract [en]

    This study originates in a recognised unsustainable cost escalation for complex defence equipment. In order to understand how such cost escalation for complex product systems (CoPS) can be avoided, this study comparatively explores four different industrial sectors – energy, transportation, healthcare and defence – with and without intergenerational increasing costs, represented by four international companies. The results, collected from studying the development of one of each company’s products, reveal some characteristic differences in market factors between those sectors and companies having problems with intergenerational escalating costs and customer affordability, as compared to other sectors and companies. It is suggested that dependent on market characteristics, it might be necessary to actively manage affordability when CoPS are developed. Efforts made by the companies to make products more affordable were identified, and several factors enabling and disabling the development of less costly products without compromising customer needs were explored. Further, the implications of affordability management in a CoPS setting are elaborated on.

  • 29.
    Andersson, Kjell
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Evaluation of a model based learning approach for engineering design2015In: INTERNATIONAL DESIGN ENGINEERING TECHNICAL CONFERENCES AND COMPUTERS AND INFORMATION IN ENGINEERING CONFERENCE, 2015, VOL 3, 2015, article id UNSP V003T04A013Conference paper (Refereed)
    Abstract [en]

    Project-based education in combination with problem based learning has been very successful, and has contributed to the popularity of engineering design education among students at technical universities. The close connection to industrial problems by the use of industry-connected projects has boosted this popularity still further and to get an insight of future working environments after graduation is very inspiring for the students.

    The curriculum of the Machine Design capstone course at KTH Department of Machine Design covers the whole process from idea generation to manufacturing and testing a final prototype. A major part of the course consists of project work where students develop a product prototype in close cooperation with an industrial partner or with a research project at the department. This means that a major part of the course uses project-based learning as a teaching strategy. In addition, a model-based design methodology is introduced which enables the students to evaluate and "experience" many different behaviors of the product using digital models in a virtual environment. In this way, students can see that many undesirable concepts and flaws can be avoided even before a prototype is manufactured.

    This paper evaluates the use and learning outcome of model-based design in a capstone course in the Engineering Design MSc program at KTH Department of Machine Design. The approach has been used during a period of three years and the effect on the students' learning has been evaluated by a questionnaire after each course. I this paper we compare the results of these questionnaires and discuss implications and general conclusions about this learning approach.

  • 30.
    Andersson, Kjell
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Bhandari, Kaviresh
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Chamoun, S.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Engel, Katrin
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Design and evaluation of a concept for storing thermal energy2012In: NordDesign 2012 - Proceedings of the 9th NordDesign Conference, Center for Industrial Production, Aalborg University and Design Society, University of Strathclyde , 2012Conference paper (Refereed)
    Abstract [en]

    Thermal energy storage technology is a promising power source for peak-power requirements in automotive applications as well as for small-scale combined heat-and-power generation. This paper reports project work made in the MF2004 Machine Design advanced course at KTH and describes the design, realization and experimental testing of a concept for storage of thermal energy. The test results were compared to the theoretical model described in the patent application of a steam buffer [1] as developed by RANOTOR AB [2] in Sigtuna, Sweden. The experimental results proved to be in correspondence with the predicted behaviour, which indicates proof of concept.

  • 31.
    Andersson, Kjell
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Hagnestål, Anders
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM).
    A flexible chain proposal for winch based point absorbers2018In: Proceedings of the ASME 2018 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference IDETC/CIE 2018: August 26-29, 2018, Quebec City, Quebec, Canada, 2018Conference paper (Refereed)
    Abstract [en]

    Ocean wave power is a promising renewable energy source for future energy production. It has however been difficult to find a cost-effective solution to convert the wave energy into electricity. The harsh marine environment and the fact that wave power is delivered with high forces at low speeds makes design of durable mechanical structures and efficient energy conversion challenging. The dimensioning forces strongly depend on the wave power concept, the Wave Energy Converter (WEC) implementation and the actual Power TakeOff (PTO) system. A WEC using a winch as a Power Take-Off system, i.e. a Winch Based Point Absorber (WBPA), could potentially accomplish a low Levelized Cost Of Energy (LCOE) if akey component - a low-cost, durable and efficient winch that can deal with high loads - can be developed. A key problem for achieving a durable winch is to find a force transmitting solution that can deal with these high loads and handle up to 80 million cycles. In this article we propose a design solution for a force transmitting chain in a WBPA system where elastomeric bearings are used as a means to achieve the relative motion between the links in the chain. With this solution no sliding is present and the angular motion is achieved as a deformation in the elastomeric bearing when the chain is winded on a drum. The link was designed primarily to minimize the number of joints in the chain: Thereby the maximum allowed relative angle between the links when rolled up over the drum should be as large as possible within practical limits. The angle is to be handled by the elastomeric bearing. A detailed strength analysis of the link has been performed as well as topology optimization to increase the strength to weight ratio. A test rig for a first proof of concept testing has been developed and the first preliminary test results indicate that this concept with using elastomeric bearings can be a potential solution for a durable chain and should be analyzed further for fatigue conditions and under water operations. 

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  • 32.
    Andersson, Kjell
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Hagnestål, Anders
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Electric Power and Energy Systems.
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Design of a flexible chain for winch based point absorbers2018In: Proceedings of NordDesign: Design in the Era of Digitalization, NordDesign 2018, 2018Conference paper (Refereed)
  • 33.
    Andersson, Kjell
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    Reality-driven virtual wheel loader operation2005In: Proceedings of Virtual Concept 2005, 2005Conference paper (Refereed)
  • 34.
    Andersson, Martin
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Sosa, Mario
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    The effect of running-in on the efficiency of superfinished gears2016In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 93, p. 71-77Article in journal (Refereed)
    Abstract [en]

    Reduced gear contact losses are necessary to keep operating temperatures, as well as fuel consumption low. In this work, an FZG gear test rig was used to investigate the effect of running-in on superfinished gears with respect to efficiency. This was compared to ground gears where a higher contact pressure yielded higher efficiency. No difference was found between the two running-in procedures when analysing superfinished gears. The effect of running-in on gears decreased when the initial surface roughness was reduced, which initially had an Ra, Rz and Rpk value of 0.08, 0.75 and 0.08 μm respectively. Superfinished gears showed an overall higher efficiency; however, a distinctly lower efficiency was present below 2 m/s when compared to ground gears.

  • 35.
    Asplund, Fredrik
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics. KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.). KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Embedded Control Systems.
    Grimheden, Martin
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics. KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Reinforcing Learning in an Engineering Master’s Degree Program: The Relevance of Research Training2019In: International journal of engineering education, ISSN 0949-149X, Vol. 35, no 2, p. 598-616Article in journal (Refereed)
    Abstract [en]

    Master students at our institute were graduating without acceptable research proficiency. We intervened by shifting our research training from teaching-centred to student-centred, and from research-related subject content to research-related processes. We performed a mixed methods study aimed to confirm there was improved research proficiency without a negative trade-off for our students’ engineering skills. Results indicated improvements to research proficiency, which our students were able to transfer to engineering-related learning activities to increase their ability to achieve engineering synthesis. This outcome was potentially supported by our courses including several perspectives on scientific knowledge production. This implies that research training, rather than having a negative effect on engineering skills, can be helpful in learning diametrically opposing aspects of thinking required by current engineering. As engineering education evolves towards more cross-disciplinary cooperation, this implies the need to pursue the increased opportunities for students to learn about different perspectives on knowledge production.

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  • 36.
    Asplund, Fredrik
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Ulfvengren, Pernilla
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Management & Technology.
    Work functions shaping the ability to innovate: insights from the case of the safety engineer2019In: Cognition, Technology & Work, ISSN 1435-5558, E-ISSN 1435-5566Article in journal (Refereed)
    Abstract [en]

    To perform as intended, firms are divided into work functions that contribute to the behaviour-shaping constraints under which individuals build their skills, knowledge and networks. These in turn provide a specialized perspective on organisational structure and culture. In a mixed methods study involving interviews and statistical analyses, we investigate whether a work function can thereby affect individuals’ innovation foci and efficacy. Safety engineers, central to firms developing Cyber-Physical Systems (CPS), are shown to play a significant role in identifying and supporting viable innovation related to organisational aspects. Results indicate that safety engineers could use the firm’s collaborative innovation process to facilitate organisational learning, helping different work functions come together to construct working practices aligned with the organisational values of the firm. This is explained by their understanding of safety culture—a specialized understanding of organisational culture and complexity provided by their work function. We conclude that work functions that provide their members with a perspective well aligned with their firm’s organisational values can instil the ability to identify and support organisational innovation. This suggests that safety engineers in CPS domains could be effective in a mediatory role, facilitating innovative changes to organisational structures and processes when introducing and operating safety management systems. Stronger aspects of organisational liaising and systems thinking could reinforce this ability—the former by a wider scope and motivation leading to an increased skill in communicating with dissimilar individuals, and the latter by providing the skills and tools needed to analyse the politics of complex organisations.

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  • 37. Athanassiou, N.
    et al.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Wahlström, J.
    Dizdar, Senad
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Simulation of thermal and mechanical performance of laser cladded disc brake rotors2022In: Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology, ISSN 1350-6501, E-ISSN 2041-305X, Vol. 236, no 1, p. 3-14Article in journal (Refereed)
    Abstract [en]

    Disc brakes wear during braking events and release airborne particulates. These particle emissions are currently one of the highest contributors to non-exhaust particle emissions and introduce health hazards as well as environmental contamination. To reduce this problem, wear and corrosion-resistant disc coatings have been implemented on grey cast iron brake disc rotors by using various deposition techniques such as thermal spraying and overlay welding. High thermal gradients during braking introduce risks of flaking off and cracking of thermally sprayed coatings with adhesive bonding to the substrate. Overlay welding by laser cladding offers metallurgical bonding of the coating to the substrate and other benefits that motivate laser cladding as a candidate for the coating of the grey cast iron brake discs. This study aims to investigate the effect of laser cladding on the thermal and thermo-structural performance of the coated grey cast iron brake discs. Therefore, thermal and thermo-stress analysis with COMSOL Multiphysics 5.6 software is performed on braking events of grey cast iron brake discs as non-coated – reference and laser cladding coated with stainless steel welding consumables. The Results demonstrated that surface temperatures were more localised, overall higher in the laser cladded coating with over three times the stresses attained of reference grey cast iron discs. The output of the simulations has been compared by tests found in the literature. Laser cladding presented higher reliability and braking performance, nonetheless requiring the evaluation of its thermal impact on other system components. 

  • 38.
    Bagchi, Satyajit
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Mahmood Reza, Khabbazi
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Onori, Mauro
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Wikander, Jan
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics. KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Application of ZUPT-Aided INS to Indoor Localization of Tightening Tools2018In: Procedia Manufacturing, Elsevier B.V. , 2018, p. 565-569Conference paper (Refereed)
    Abstract [en]

    This paper presents the application of zero velocity detectors in the field of indoor positioning for industrial tightening tools particularly in tandem with an extended Kalman filter to achieve reliable estimates in position. Inertial measurement units are promising devices to use in positioning systems. Data has been collected from IMU while moving in a predefined trajectory on a tightening test rig and post-processed in MATLAB using the implemented algorithms and the results are presented. They indicate that the error accumulation can be effectively controlled to 25 cm/min for the commercial grade IMU and 15 cm/min for the navigation grade IMU. 

  • 39.
    Becker, Matthias
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Electronics and Embedded systems, Electronic and embedded systems.
    Lu, Zhonghai
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Electronics and Embedded systems, Electronic and embedded systems.
    Chen, DeJiu
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics. KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    An adaptive resource provisioning scheme for industrial SDN networks2019In: IEEE International Conference on Industrial Informatics (INDIN), Institute of Electrical and Electronics Engineers Inc. , 2019, p. 877-880Conference paper (Refereed)
    Abstract [en]

    Many industrial domains face the challenge of ever growing networks, driven for example by Internet-of-Things and Industry 4.0. This typically comes together with increased network configuration and management efforts. In addition to the increasing network size, these domains typically are subject to adaptive load situations that pose an additional challenge on the network infrastructure.Software defined networking (SDN) is a promising networking paradigm that reduces configuration complexity and management effort in Ethernet networks. In this work, we investigate SDN in context of adaptive scenarios with QoS constraints. Our approach applies monitoring of several thresholds which automatically trigger redistribution of resources via the central SDN controller. This setup leads to an agile system that can dynamically react to load changes while the infrastructure is not overprovisioned. The approach is implemented in a low-level simulation environment where we demonstrate the benefits of the approach using a case study.

  • 40.
    Becker, Matthias
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Electronics and Embedded systems, Electronic and embedded systems.
    Lu, Zhonghai
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Electronics and Embedded systems, Electronic and embedded systems.
    Chen, DeJiu
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.). KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Towards QoS-Aware Service-Oriented Communication in E/E Automotive Architectures2018In: Proceedings of the 44th Annual Conference of the IEEE Industrial Electronics Society (IECON), Institute of Electrical and Electronics Engineers (IEEE), 2018, p. 4096-4101, article id 8591521Conference paper (Refereed)
    Abstract [en]

    With the raise of increasingly advanced driving assistance systems in modern cars, execution platforms that build on the principle of service-oriented architectures are being proposed. Alongside, service oriented communication is used to provide the required adaptive communication infrastructure on top of automotive Ethernet networks. A middleware is proposed that enables QoS aware service-oriented communication between software components, where the prescribed behavior of each software component is defined by Assume/Guarantee (A-G) contracts. To enable the use of COTS components, that are often not sufficiently verified for the use in automotive systems, the middleware monitors the communication behavior of components and verifies it against the components A/G contract. A violation of the allowed communication behavior then triggers adaption processes in the system while the impact on other communication is minimized. The applicability of the approach is demonstrated by a case study that utilizes a prototype implementation of the proposed approach.

  • 41.
    Bejefalk, Thomas
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development. KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Att konstruera för tillverkning: En arbetsmodell för ett enstyckskonstruerande företag2010Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    DynaMate AB, the owner of DynaMate Industrial Services AB (DIS), is a free-standing whollyownedaffiliate company of Scania CV AB. The company started its business in 1993 initially as asupport and maintenance department within and for Scania solely. During the first six-months of2001 DynaMate’s business was re-formed to also offer its service and production support to otherclients besides Scania. Therefore, in 2009 DynaMate Industrial Services AB was established. Thiscompany offer complete industrial solutions with special skills in the automation, electrical andmechanical areas.In the management of Scania, DynaMates missions has often depended on single designers, playingthe role as both project leader and project member as well as project performer and finisher. As aeffect of this working procedure many crucial decisions have been only verbal and informal, whereimportant task documentation and possible drawings rectifications has been inadequate. The factthat DIS now, continuously increasing in extent, is aiming to other clients than just Scania, a morestandardized working procedure is required. This is important to be able to decrease time from ideato complete solution, and still provide customers with high quality products.The primary task with this project was therefore to develop a working model proposal forimproving designers’ every-day work at DIS, concerning reduced lead time for one-productmanufacturing.This Master Thesis was performed with the support from litterature within associated research area,followed by the formation of a interview questionnaire. All interviews were performed within DISdepartment of mechanical design and with external manufacturing companies.The compiled result indicated several areas that a designer must be aware of when designing formanufacturing. Manufacturers pointed out that the most common defects with constructiondelivered drawings are missing measurements, as well as superflously tolerances, radius’ andchamfers. These factors are all contributing to increased lead time and product complexity.The proposed new working model presented in this Master Thesis is a phase-divided sequentialprocess, where both the customer and manufacturer will be more involved than today. This toensure that the manufacturer will be given complete data from the designer, and that the finalproduct will obtain customer satisfaction.

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  • 42.
    Bergman, Anton
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Eriksson, Robin
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Grahn, Lars-Fredrik
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Self-levelling Platform Concept for a Winch-based, Single Point Absorbing, Wave Energy Converter2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report covers a bachelor thesis project to design a concept for a levelling system to a point absorbing wave energy converter that uses a winch with a chain, which has restricted capabilities to bending and thus requires a system which compensates for this. First of all, a literature study was made to see if there were any technologies that could be used, and also a wide search for information about the wave conditions in the Baltic sea were performed to find what requirements would be necessary for the concept to be able to withstand the conditions faced there. Following this, several brainstorming sessions were had to get ideas for different types of constructions that could solve the problem. After multiple ideas had been conceptualized, they were rated in a Pugh matrix with five different criteria which were: 1. mechanical complexity 2. complexity of required motion control 3. complexity of the structure 4. amount of potential critical weak points 5. mass of the system and lastly 6. how symmetrical it could be made. The concept that was deemed most viable out of all them is a cradle that holds the winch-drum and is controlled by a motor to compensate for one angular shift, and this is paired with a mooring system that limits the yawing motion of the entire buoy and thus removes the need for the compensation of that angle. This concept was then modelled in Solid Edge and following this; a stress analysis was made to determine the forces that would act upon the system. These were then used to determine whether the system would live up to the requirements or not with fatigue calculations. Lastly a list of recommended future work is presented.

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  • 43.
    Bergseth, Ellen
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Influence of surface topography and lubricant design in gear contactsLicentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The purpose of this thesis was to study the influence of manufacturing variations on gear performance. The manufacturing variations inherent in different manufacturing methods were studied to include the effect of real surfaces. Real surfaces have surface irregularities at least on some scale, which can significantly influence how loads are transmitted at the gear contact. To some extent, the lubricant design can help to prevent contact that could lead to tooth failures by forming a protective surface boundary layer. An experimental study was used to consider the compositions of these layers with a surface analysis method.

    In Paper A a robust design approach was used to find out to what extent the current standard for calculation of surface durability treats manufacturing variations and the choice of lubricant. The results show that the simplest calculation method used is not enough to predict the effect of these on surface durability. Additionally, the standard quality levels are poorly incorporated in the standard calculating procedures for surface durability, and the quality of the gear tooth is restricted to include only a few parameters.

    In Paper B a pin-on-disc machine was used to evaluate the tribofilm formation by the additives and the corresponding wear occurring in the boundary lubrication regime in environmentally adapted lubricants. Studies of the additive and base fluid interaction were carried out using glow discharge-optical emission spectroscopy. It was found that the chemically reacted surface boundary layers played an important role in terms of wear. More specifically, the oxide layer thickness had significant influence on wear. The findings also demonstrate the complexity of lubrication design formulations coupled to these layers. For example, it was found that the pre-existing surface boundary layer (before any lubricant had been added) played an important role in allowing the lubricant to react properly with the surfaces.

    The aim of Paper C was to contribute to the knowledge of how different surface topographies, tied to manufacturing methods, influence the early life contact conditions in gears. Topographical measurements of differently manufactured tooth flanks were used as data input to a contact analysis program. The variation in surface topography inherent in the manufacturing method was found to have a strong influence on the contact area ratio.

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  • 44.
    Bergseth, Ellen
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements. KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Tribologi.
    Henriksson, Mats
    Scania CV.
    Broukhiyan, Parsa
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Sugutur, Lohith
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Nordin, Erland
    Scania CV.
    EFFECTS OF THRUST WASHER BEARING SURFACE CHARACTERISTICS ON PLANETARY GEAR TRAIN WEAR2017Conference paper (Refereed)
  • 45.
    Bergseth, Ellen
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements. KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Tribologi.
    Söderberg, Anders
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements. KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Tribologi.
    Zhu, Yi
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements. KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Tribologi.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Study of surface roughness and surface orientation on friction in rolling/sliding contacts: barrel-on-disc versus twin-disc2017Conference paper (Refereed)
    Abstract [en]

    Gears are one of the most important means of mechanical power transmission. Even though the efficiency is high for a gear pair today, further decrease in friction can contribute to lower the fuel consumption. A barrel-on-disc machine (same setup as ball-on-disc) to simulate a rolling/sliding gear contact was used to study the impact of manufacturing method, grinding and superfinishing, on friction. To evaluate the extent to which friction and wear can be diminished by reducing surface roughness and changing surface orientation. Measurement results showed that the change of lubricant had an impact on friction in the mixed to boundary lubrication regimes similar to that of the change of main surface orientation. The results were compared with those from a parallel study involving a twin-disc machine, also used to simulate rolling/sliding contacts (see Figure). Measurements and simulations showed that the barrel-on-disc and twin-disc setups reflected the same friction trends. However, the friction coefficient using the barrel-on-disc setup was almost twice as large as that found using the twin-disc machine. The wear mechanisms also differed: micropits occurred on discs used in the twin-disc set-up whereas normal or no wear was found on the barrel-on-disc specimens. The difference in contact geometry is believed to be the main reason for the higher friction level in the barrel-on-disc machine. A computer contact analysis was used to clarify the differences using perfectly smooth and computer-generated textured surfaces.

  • 46.
    Bergseth, Ellen
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Zhu, Yi
    Zhejiang Univ, Zheda Rd 38, Hangzhou 310027, Peoples R China..
    Söderberg, Anders
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Study of Surface Roughness on Friction in Rolling/Sliding Contacts: Ball-on-Disc Versus Twin-Disc2020In: Tribology letters, ISSN 1023-8883, E-ISSN 1573-2711, Vol. 68, no 2, article id 69Article in journal (Refereed)
    Abstract [en]

    Although the efficiency of a gear pair is currently high, a better understanding of surface/lubricant contribution on efficiency is critical. Electrified drivelines will, for example, impose higher speed and alternate loading, and it is expected that these new conditions will, to a greater extent, rely on the surface/lubricant characteristics. Phenomena taking place in the gear contact is often measured using ball-on-disc and twin-disc tribometers. In this study, these two test set-ups were compared in order to assess differences in the behaviour of surface/lubricant interactions. Results showed that ball-on-disc and twin-disc set-ups reflect the same friction trends. However, the friction results differed by a factor of roughly two, even though the tribometers were set-up to run at the same contact pressure. The wear mechanisms also differed: micropits occurred on discs used in the twin-disc set-up, whereas normal or no wear was found on the ball-on-disc specimens. The contact conditions for the two test set-ups were also analysed using a numerical model. The comparison of these two machines may aid gear designers in selecting the proper experimental set-up for their purpose.

  • 47. Bergsjö, D.
    et al.
    Vielhaber, M.
    Malvius, Diana
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Burr, H.
    Malmqvist, J.
    Product lifecycle management for cross-x engineering design2007In: Proceedings of ICED 2007, the 16th International Conference on Engineering Design, 2007Conference paper (Refereed)
    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.

  • 48. Bergsjö, Dag
    et al.
    Malvius, Diana
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Use of Information Management Systems from Designers' Perspective2006In: PROCEEDINGS OF NORDDESIGN 2006 CONFERENCE, REYKJAVIK: UNIV ICELAND, FAC ENGINEERING, , 2006, p. 179-190Conference paper (Refereed)
    Abstract [en]

    In product development research, studies that aim at identifying best practice methods and processes are often conducted. However, it is also essential to learn about causes for bad practice and to gain understanding about how to avoid it. In complex product development, design engineers have to meet the challenges of increased product functionality but their needs for multidisciplinary integration of information are not sufficiently met by existing information management systems. This prevents the design engineers from working at their full capacity and inhibits the possibilities to get support for innovative and value-adding work. This paper aims at identifying reasons for non value-adding work that is linked to inefficient information support, and especially to the use of information management systems. It can be concluded that designers have difficulties to acknowledge positive effects such as better product quality or lower costs that are connected to the use of information management systems. It is argued that one potential means for improved information integration is by managing a trade-off between standardised and customised IT tools and systems.

  • 49.
    Bergstedt, Edwin
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Holmberg, Anders
    Uppsala.
    Lindholm, Per
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Influence of the DIN 3962 Quality Class on the Efficiency in Honed Powder Metal and Wrought Steel Gears2020In: Tribology Transactions, ISSN 1040-2004, E-ISSN 1547-397X, Vol. 63, no 6, p. 1076-1084Article in journal (Refereed)
    Abstract [en]

    To increase the efficiency of a gearbox, research on gear mesh loss is of importance. Britton et al. concluded that the surface finishing method affects the gear mesh efficiency. The efficiency benefits of superfinishing a surface and reducing the surface roughness have been reported by Kahraman. A novel method for calculating the bearing loss torque was proposed by Tu et al. Andersson et al. found that the efficiency can vary between 2 and 5% during repeated efficiency tests due to variations in the assembly process. This work investigates how the honing surface finishing process and DIN 3962 quality class affect the gear mesh efficiency by performing tests in an FZG back-to-back test rig. Two materials, a powder metal and a wrought steel, were tested. All gears were finished using a honing process and sorted according the measured quality class. Powder metal gears of class 6, 7, 8, and ≥9 and wrought steel gears of class 6, 7, and ≥9 were tested. The efficiency were calculated from measuring the torque required to maintain a constant velocity of the FZG test rig. The results from the efficiency tests showed no significant difference in efficiency between the wrought steel and powder metal steel gears. In addition, no obvious correlation between the DIN 3962 quality class and the gear mesh efficiency could be found. When examining the wrought steel material it was found that the reproducibility of the efficiency was comparable to the assembly error of the test rig, despite the variation in quality class.

  • 50.
    Bergstedt, Edwin
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Lin, Jiachun
    Beijing Univ Technol, Dept Instrument Sci & Technol, Fac Mat & Mfg, Beijing, Peoples R China..
    Andersson, Michael
    Hoganas AB, R&D, SE-26383 Hoganas, Sweden..
    Bergseth, Ellen
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Gear micropitting initiation of ground and superfinished gears: Wrought versus pressed and sintered steel2021In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 160, article id 107062Article in journal (Refereed)
    Abstract [en]

    This paper investigates the resistance of micropitting on two materials, using an FZG back-to-back test rig with CPT gears. The materials are wrought steel (16MnCr5) and a commercial powder metallurgical material (AstaloyTM Mo). Two finishing methods were studied: grinding and superfinishing. Experimental results show that the superfinishing prevented micropitting, but led to premature failure due to cracks in the root caused by tip-to-root interference. Micropitting was initiated at a higher load stage for the powder metallurgical steel compared to the ground wrought steel. The failure mechanisms were similar between materials with the same surface finish. The powder metallurgical steel showed subsurface initiated fatigue compared to the wrought ground steel having surface-initiated fatigue. Testing new finishing methods and materials, one has to be aware of the influence of the gear micro geometry.

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