liu.seSearch for publications in DiVA
Change search
Refine search result
12 1 - 50 of 82
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Amadori, Kristian
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Tarkian, Mehdi
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Krus, Petter
    Linköping University, Department of Management and Engineering, Fluid and Mechatronic Systems. Linköping University, The Institute of Technology.
    Flexible and Robust CAD Models for Design Automation2012In: Advanced Engineering Informatics, ISSN 1474-0346, E-ISSN 1873-5320, Vol. 26, no 2, p. 180-195Article in journal (Refereed)
    Abstract [en]

    This paper explores novel methodologies for enabling Multidisciplinary Design Optimization (MDO) of complex engineering products. To realize MDO, Knowledge Based Engineering (KBE) is adopted with the aim of achieving design reuse and automation. The aim of the on-going research at Linköping University is to shift from manual modelling of disposable geometries to Computer Aided Design (CAD) automation by introducing generic high-level geometry templates. Instead of repeatedly modelling similar instances of objects, engineers should be able to create more general models that can represent entire classes of objects. The proposed methodology enables utilization of commercial design tools, hence taking industrial feasibility into consideration. High Level CAD templates (HLCt) will be proposed and discussed as the building blocks of flexible and robust CAD models, which in turn enables high-fidelity geometry in the MDO loop. Quantification of the terms flexibility and robustness is also presented, providing a means to measure the quality of the geometry models. Finally, application examples are presented in which the outlined framework is evaluated. The applications have been chosen from three ongoing research projects aimed at automating the design of transport aircraft, industrial robots, and micro air vehicles.

  • 2.
    Andersson, Henric
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Carlsson, Magnus
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Towards Configuration Support for Collaborative Simulator Development: A Product Line Approach in Model Based Systems Engineering2011In: Proceedings of the 2011 20th IEEE International Workshops on Enabling Technologies, WETICE 2011: Infrastructure for Collaborative Enterprises, IEEE conference proceedings, 2011, p. 185-192Conference paper (Other academic)
    Abstract [en]

    In development and support of complex products such as power plants, automotive vehicles, or aircrafts, modeling and simulation has become an important activity as a basis for knowledge capture. Simulation is used in several steps of the product lifecycle; for evaluation of early design, for system verification, and for user training. With emerging techniques such as tools for high-level modeling, multi-core computing, and visualization, the number of useful models is growing. This paper focuses on reuse of multipurpose models and configuration support in a product line context. A configurator prototype system is presented. The simulator set created from validated models is considered to be a secondary product line. The product set which the simulation models represent is considered to be the primary product line. The Saab Gripen fighter aircraft, together with simulators in which the aircraft behavior, performance, and handling qualities are represented, is used to exemplify application. Integration principles of the systems for simulator configuration, Software Configuration Management, and Product Data Management (PDM) are studied. Preliminary results show that a configurator tool can be used, but there is need to map structures between the simulation and PDM domains.

  • 3.
    Andersson, Henric
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Herzog, Erik
    Saab Aeronautics, Linköping, Sweden.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Experience from Model and Software Reuse in Aircraft Simulator Product Line Engineering2013In: Information and Software Technology, ISSN 0950-5849, E-ISSN 1873-6025, Vol. 55, no 3, p. 595-606Article in journal (Refereed)
    Abstract [en]

    Context: "Reuse" and "Model Based Development" are two prominent trends for improving industrial development efficiency. Product lines are used to reduce the time to create product variants by reusing components. The model based approach provides the opportunity to enhance knowledge capture for a system in the early stages in order to be reused throughout its lifecycle. This paper describes how these two trends are combined to support development and support of a simulator product line for the SAAB 39 Gripen fighter aircraft.

    Objective: The work aims at improving the support (in terms of efficiency and quality) when creating simulation model configurations. The objective is to increase the level of reuse when combining and customizing models for usage in a range of development and training simulators.

    Method: The research has been conducted with an interactive approach using prototyping and demonstrations, and the evaluation is based on an iterative and a retrospective method.

    Results: A product line of simulator models for the SAAB 39 Gripen aircraft has been analyzed and defined in a Product Variant Master. A configurator system has been implemented for creation, integration, and customization of stringent simulator model configurations. The system is currently under incorporation in the standard development process at SAAB Aeronautics.

    Conclusion: The explicit and visual description of products and their variability through a configurator system enables better insights and a common understanding so that collaboration on possible product configurations improves and the potential of software reuse increases. The combination of application fields imposes constraints on how traditional tools and methods may be utilized. Solutions for Design Automation and Knowledge Based Engineering are available, but their application has limitations for Software Product Line engineering and the reuse of simulation models.

  • 4.
    Andersson, Henric
    et al.
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Weitman, Anders
    Saab Aerosystems, Sweden.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Simulink as a Core Tool in Development of Next Generation Gripen2008In: Proceedings of Nordic Matlab User Conference 2008, Stockholm, Sweden, 2008Conference paper (Other academic)
    Abstract [en]

    In the planning and concept study phases of the next generation Gripen fighter aircraft, methods and tools studies have been performed. Capabilities and limitations of the Simulink toolset have been evaluated to explore how it can support model based systems/software engineering. In this paper, three different approaches of Simulink usage for functional development are presented:

    1. The functional oriented systems modeling and simulation approach where the function is in focus; complete enough to be simulatable, but abstract from an implementation point of view.
    2. An implementation oriented specification approach that is based on a modeling framework with predefined system architecture, scheduling, data types and rules for discretization. The resulting embedded software is hand coded using the model as specification.
    3. Similar to approach two but here the embedded software is automatically generated using a high quality code generator.

    The driver for choosing approach is threefold; high quality, short development time and low cost. Some experiences based on these prerequisites are presented, mainly concerning the aspects of scalability, such as; model architecture, license model and project ramp-up challenges. The results are also compared to the existing SystemBuild based development environment. When introducing high-end engineering practices and tools such as Simulink in an organization developing safety-critical products, it is important to make sure that also basic management practices (e.g. Requirements-, Configuration- and Change Management) are thoroughly handled.

  • 5.
    Andersson, Torbjörn
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Warell, Anders
    Division of Industrial Design, Dept of Design Sciences, Lund University,.
    Holmlid, Stefan
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, The Institute of Technology.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Desirability in the development of In-Car Infotainment Systems2011In: Workshop: User Experience in Cars / [ed] David Wilfinger, 2011Conference paper (Other academic)
    Abstract [en]

    This paper describes a workflow for designing experiences whileinteracting with an advanced driver assistant system. Future driver assistancesystems that utilize sensors and Car2X-communication in order to detect threatsin the car environment can help the driver to avoid collisions. To increase theacceptance of such a system, the interaction between the driver and the systemshould be able to generate positive experiences. To generate those experiences,a story-based design workflow was used. Concepts created with this workflowshould be able to address specific psychological needs of the driver. Theimplementation of this workflow revealed different schemes of positiveexperiences during driver interaction in critical situations.

  • 6.
    Björn, Johansson
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Ölvander, Johan
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Machine Design.
    Pettersson, Marcus
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Machine Design.
    Component Based Modelling And Optimization For Modular Robot Design2007In: ASME Design Automation Conferance,2007, Las Vegas: ASME , 2007, p. 911-920Conference paper (Refereed)
    Abstract [en]

    In this paper, an approach for modular design of industrial robots is presented. The approach is to introduce an objectoriented simulation model of the robot and combine this with a discrete optimization algorithm. The simulation model of the industrial robot is developed in Modelica, an object oriented modeling and simulation language, and simulated in the Dymola tool. The optimization algorithm used is a modification of the Complex method that has been developed in Matlab and connected to the simulation program. The optimization problem includes selecting components such as gearboxes and motors from a component catalogue and the objective function considers minimization of cost with constraints on gear box lifetime. Furthermore, the correctness of the model has been verified by comparison with an in-house simulation code with high accuracy.

  • 7.
    Carlsson, Magnus
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Andersson, Henric
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Gavel, Hampus
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Methodology for Development and Validation of Multipurpose Simulation Models2012In: 50th AIAA Aerospace Sciences Meeting Online Proceedings including the New Horizons Forum and Aerospace Exposition (2012), AIAA , 2012Conference paper (Refereed)
    Abstract [en]

    This paper describes a framework for development and validation of multipurpose simulation models. The presented methodology enables reuse of models in different applications with different purposes. The scope is simulation models representing physical environment, physical aircraft systems or subsystems, avionics equipment, and electronic hardware. The methodology has been developed by a small interdisciplinary team, with experience from Modeling and Simulation (M&S) of vehicle systems as well as development of simulators for verification and training. Special care has been taken to ensure usability of the workflow and method descriptions, mainly by means of 1) a user friendly format, easy to overview and update, 2) keeping the amount of text down, and 3) providing relevant examples, templates, and checklists. A simulation model of the Environmental Control System (ECS) of a military fighter aircraft, the Saab Gripen, is used as an example to guide the reader through the workflow of developing and validating multipurpose simulation models. The methods described in the paper can be used in both military and civil applications, and are not limited to the aircraft industry.

  • 8.
    Carlsson, Magnus
    et al.
    Saab Aeronautics, Linköping, Sweden.
    Gavel, Hampus
    Saab Aeronautics, Linköping, Sweden.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Evaluating Model Uncertainty Based on Probabilistic Analysis and Component Output Uncertainty Descriptions2012In: Proceedings of the ASME 2012 International Mechanical Engineering Congress & Exposition: IMECE2012-85236 / [ed] ASME, 2012Conference paper (Other academic)
    Abstract [en]

    To support early model validation, this paper describes a method utilizing information obtained from the common practice component level validation to assess uncertainties on model top level. Initiated in previous research, a generic output uncertainty description component, intended for power-port based simulation models of physical systems, has been implemented in Modelica. A set of model components has been extended with the generic output uncertainty description, and the concept of using component level output uncertainty to assess model top level uncertainty has been applied on a simulation model of a radar liquid cooling system. The focus of this paper is on investigating the applicability of combining the output uncertainty method with probabilistic techniques, not only to provide upper and lower bounds on model uncertaintiesbut also to accompany the uncertainties with estimated probabilities.It is shown that the method may result in a significant improvement in the conditions for conducting an assessment of model uncertainties. The primary use of the method, in combination with either deterministic or probabilistic techniques, is in the early development phases when system level measurement data are scarce. The method may also be used to point out which model components contribute most to the uncertainty on model top level. Such information can be used to concentrate physical testing activities to areas where it is needed most. In this context, the method supports the concept of Virtual Testing.

  • 9.
    Carlsson, Magnus
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Gavel, Hampus
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Utilizing Uncertainty Information in Early Model Validation2012In: AIAA Modeling and Simulation Technologies Conference / [ed] AIAA, 2012Conference paper (Other academic)
    Abstract [en]

    This paper proposes a pragmatic approach enabling early model validation activities with a limited availability of system level measurement data. The method utilizes information obtained from the common practice of component validation to assess uncertainties on model top level. Focusing on industrial applicability, the method makes use of information normally available to engineers developing simulation models of existing or not yet existing systems. This is in contrast to the traditional sensitivity analysis requiring the user to quantify component parameter uncertainties – a task which, according to the authors’ experience, may be far from intuitive. As the proposed method enables uncertainties to be defined for a component’s outputs (characteristics) rather than its inputs (parameters), it is hereby termed output uncertainty. The method is primarily intended for use in large-scale mathematical 1-D dynamic simulation models of physical systems with or without control software, typically described by Ordinary Differential Equations (ODE) or Differential Algebraic Equations (DAE).It is shown that the method may result in a significant reduction in the number of uncertain parameters that require consideration in a simulation model. The uncertainty quantification of these parameters also becomes more intuitive. Since this implies a substantial improvement in the conditions of conducting sensitivity analysis or optimization on large-scale simulation models, the method facilitates early model validation. In contrast to sensitivity analysis with respect to a model’s original component parameters, which only covers one aspect of model uncertainty, the output uncertainty method enables assessment also of other kinds of uncertainties, such as uncertainties in underlying equations or uncertainties due to model simplifications. To increase the relevance of the method, a simulation model of a radar liquid cooling system is used as an industrial application example.

  • 10.
    Carlsson, Magnus
    et al.
    Saab Aeronautics, Linköping, Sweden.
    Steinkellner, Sören
    Saab Aeronautics, Linköping, Sweden.
    Gavel, Hampus
    Saab Aeronautics, Linköping, Sweden.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Enabling Uncertainty Quantification of Large Aircraft System Simulation Models2013In: 4:th CEAS conference, 2013 / [ed] Tomas Melin, Petter Krus, Emil Vinterhav, Knut Övrebo, Linköping University Electronic Press , 2013Conference paper (Refereed)
    Abstract [en]

    A common viewpoint in both academia and industry is that that Verification, Validation and Uncertainty Quantification (VV&UQ) of simulation models are vital activities for a successful deployment of model-based system engineering. In the literature, there is no lack of advice regarding methods for VV&UQ. However, for industrial applications available methods for Uncertainty Quantification (UQ) often seem too detailed or tedious to even try. The consequence is that no UQ is performed, resulting in simulation models not being used to their full potential.

    In this paper, the effort required for UQ of a detailed aircraft vehicle system model is estimated. A number of methodological steps that aim to achieve a more feasible UQ are proposed. The paper is focused on 1‑D dynamic simulation models of physical systems with or without control software, typically described by Ordinary Differential Equations (ODEs) or Differential Algebraic Equations (DAEs). An application example of an aircraft vehicle system model is used for method evaluation.

  • 11.
    Eek, Magnus
    et al.
    Saab Aeronautics, Linköping, Sweden.
    Karlén, Johan
    Saab Aeronautics, Linköping, Sweden.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, Faculty of Science & Engineering.
    A Framework for Early and Approximate Uncertainty Quantification of Large System Simulation Models2015In: Proceedings of the 56th Conference on Simulation and Modelling (SIMS 56), October, 7-9, 2015, Linköping University, Sweden, Linköping: Linköping University Electronic Press, 2015, p. 91-104Conference paper (Refereed)
    Abstract [en]

    Uncertainty Quantification (UQ) is vital to ensure credibility in simulation results and to justify model-based design decisions – especially in early development phases when system level measurement data for traditional model validation purposes are scarce. Central UQ challenges in industrial applications are computational cost and availability of information and resources for uncertainty characterization. In an attempt to meet these challenges, this paper proposes a framework for early and approximate UQ intended for large simulation models of dynamical systems. A Modelica simulation model of an aircraft environmental control system including a liquid cooling circuit is used to evaluate the industrial applicability of the proposed framework.

  • 12.
    Eek, Magnus
    et al.
    Saab Aeronautics, Linköping, Sweden.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Linköping, Sweden.
    Gavel, Hampus
    Saab Aeronautics, Linköping, Sweden.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Study of Industrially Applied Methods for Verification, Validation & Uncertainty Quantification of Simulator Models2015In: International Journal of Modeling, Simulation, and Scientific Computing, ISSN 1793-9623, E-ISSN 1793-9615, Vol. 6, no 2, article id 1550014Article in journal (Refereed)
    Abstract [en]

    To better utilize the potential of system simulation models and simulators, industrially applicable methods for Verification, Validation and Uncertainty Quantification(VV&UQ) are crucial. This paper presents an exploratory case study of VV&UQ techniquesapplied on models integrated in aircraft system simulators at Saab Aeronauticsand in driving simulators at the Swedish National Road and Transport Research Institute(VTI). Results show that a large number of Verification and Validation (V&V)techniques are applied, some of which are promising for further development and use insimulator credibility assessment. Regarding the application of UQ, a large gap betweenacademia and this part of industry has been identified, and simplified methods areneeded. The applicability of the NASA Credibility Assessment Scale (CAS) at the studied organizations is also evaluated and it can be concluded that the CAS is consideredto be a usable tool for achieving a uniform level of V&V for all models included in asimulator, although its implementation at the studied organizations requires tailoringand coordination.

  • 13.
    Ericson, Liselott
    et al.
    Linköping University, Department of Management and Engineering, Fluid and Mechatronic Systems. Linköping University, The Institute of Technology.
    Johansson, Andreas
    Linköping University, Department of Management and Engineering, Fluid and Mechatronic Systems. Linköping University, The Institute of Technology.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Palmberg, Jan-Ove
    Linköping University, Department of Management and Engineering, Fluid and Mechatronic Systems. Linköping University, The Institute of Technology.
    Optimisation of Structure Borne Noise and Fluid Borne Noise from Fluid Power Pumps and Motors2009In: Proc. of the 11th Scandinavian Fluid Power Conference, 2009Conference paper (Other academic)
    Abstract [en]

    Structure borne noise in a machine rises from piston force and bending moments among others. This noise arises directly from the pump shell. In this study, a transfer function methodology is employed for mapping simulated internal pump dynamics, such as piston forces and bending moments, on to structure borne noise. Using these transfer functions, it is possible to predict how, for instance, changed valve plate timing affects simulated piston forces and bending moments and in turn how that will affect audible noise. Hence, it is possible to design an objective function that directly reflects audible noise. The transfer functions are experimentally obtained and are valid for a specific machine shell and to some minor extent the room’s acoustical properties. Also, fluid borne noise is important to consider when designing a quiet machine. Fluid borne noise arises mainly from flow pulsation created inside the machine.

    Simulation of the internal pump dynamics, and optimisations, are carried out using a pump model developed in the simulation tool HOPSAN. The design application is a hydraulic machine of bent axis type with seven pistons. The theory outlined and the method proposed in the paper can also be applied to other types of hydraulic machines. The paper shows how both structure borne noise and fluid borne noise can be considered using multi-objective optimisation. The paper shows how different noise reduction features affect the sound pressure level and the flow pulsation. The paper also compare the pump and motor case.

  • 14.
    Ericson, Liselott
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Fluid and Mechanical Engineering Systems .
    Ölvander, Johan
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Machine Design.
    Palmberg, Jan-Ove
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Fluid and Mechanical Engineering Systems.
    En effektiv metod för att reducera flödespulsationer från variabla hydraulmaskiner2007In: Hydraulikdagar 07,2007, Linköping: Linköpings universitet , 2007Conference paper (Other academic)
    Abstract [sv]

     Den här presentationen behandlar en metod som effektivt reducerar flödespulsationer i variabla hydraulmaskiner, genom att förskjuta dödpunktens läge. Det realiseras genom att införa en fast inklinationsvinkel vinkelrätt mot den normala deplacementsvinkeln. Genom att förskjutningsvinkeln ändrar kolvarnas dödpunkt kommer förkompressionen och efterexpansionen att variera när deplacementet ändras. Tidigare arbeten visar, både teoretiskt och experimentellt, fördelarna med förskjutningsvinkeln för pumpar men inga utförligare utredningar för maskiner som arbetar både som motor och pump.

  • 15.
    Ericson, Liselott
    et al.
    Linköping University, Department of Management and Engineering, Fluid and Mechanical Engineering Systems. Linköping University, The Institute of Technology.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Palmberg, Jan-Ove
    Linköping University, Department of Management and Engineering, Fluid and Mechanical Engineering Systems. Linköping University, The Institute of Technology.
    Flow pulsation reduction for variable displacement motors using cross-angle2007In: Power Transmission and Motion Control (PTMC 2007) / [ed] D. N. Johnston, and A. Plummer, Essex: Hadleys Ltd , 2007, p. 103-116Conference paper (Refereed)
    Abstract [en]

    This paper considers using the cross-angle in variable displacement hydraulic machines. The cross-angle is a fixed displacement angle around the axis perpendicular to the normal displacement direction. The cross-angle changes the angles to the pistons top and bottom dead centres as a function of the fraction of displacement in such a way that the valve plate timing is varied and different pre-compression and decompression angles are obtained. A non-gradient optimisation technique, the Complex method, is used together with a comprehensive simulation model in order to find the optimal cross-angle for a variable displacement hydraulic motor. The paper shows that the cross-angle can be used to reduce noise in variable displacement motors. One issue that makes the motor application more difficult is the increased dependence between outlet and inlet flow ripple which is not found in pump applications. Furthermore, the paper discusses how to use the cross-angle for machines which can work both as a motor and a pump.

  • 16.
    Ericson, Liselott
    et al.
    Linköping University, Department of Management and Engineering, Fluid and Mechanical Engineering Systems. Linköping University, The Institute of Technology.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Palmberg, Jan-Ove
    Linköping University, Department of Management and Engineering, Fluid and Mechanical Engineering Systems. Linköping University, The Institute of Technology.
    On optimal design of hydrostatic machines2008In: Proceedings of the 6th International Fluid Power Conference, IFK, Vol WS, 2008, p. 273-286Conference paper (Refereed)
    Abstract [en]

    Noise is a well known challenge for hydraulic systems and hydrostatic machines is one of the largest noise contributors in a hydraulic system. The noise from the machine originates from flow pulsations in the discharge and suction ports, as well as pulsations in piston forces and bending moments. To the design a quite hydraulic machine is a difficult task where many different objectives need to be considered. This paper presents a generic method for how optimization based on simulation models could be used to design quieter hydraulic machines. In order to stay competitive on a global market an efficient product development process is essential for all manufacturing industries. By using simulation-s tools in the design process, the product can be analysed before the actual product is manufactured. Furthermore, in order to find an optimal design of the machine with respect to noise, a comprehensive dynamic simulation model is needed. The model contains all important noise contributors. In the paper, the simulation models are used together with a non-gradient optimization method in order to find the best possible design. A vital part when using optimization to support design is always to formulate the objective function. As mentioned above, noise is generated from different sources and all these sources need to be considered when the objective function is formulated. For example a design that minimizes flow pulsations in the suction port will surely perform badly in some other objective. Therefore noise minimization could be looked upon as a typical multi-objective optimization problem. It is also not evident how the different objective should be ranked because the observed noise level is strongly depending on the system in which the machine is to be used. The paper also considers whether the objective function should be formulated in time or frequency domain. Traditionally, simulation of machine performance is conducted in the time domain, but the human ear hears noise in the frequency domain and perceives high and low frequencies differently. Furthermore, transformation from piston forces into emitted noise is much higher at high-frequency content than low-frequency content. This makes it natural to formulate the objective function in frequency domain, which raises the question of how the different harmonic should be ranked. In the paper a number of different approaches to formulate the objective function is presented and evaluated. The objectives considered are flow pulsation in both discharge and suction ports, as well as pulsation in piston forces and bending moments. Furthermore, the objectives are studied in both time and frequency domain. The design application is a variable hydraulic machine of bent axis type with nine pistons, which is operated both as a pump and a motor. However, the methods presented in the paper could be applied to other types of hydraulic machines as well. 

  • 17.
    Ericson, Liselott
    et al.
    Linköping University, Department of Management and Engineering, Fluid and Mechanical Engineering Systems . Linköping University, The Institute of Technology.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Palmberg, Jan-Ove
    Linköping University, Department of Management and Engineering, Fluid and Mechanical Engineering Systems . Linköping University, The Institute of Technology.
    Johansson, Andreas
    Pump and motor division Parker Hannifin AB.
    Prediction and Optimisation of Audible Noise from Fluid Power Machines2009In: The Seventh International Conference on Fluid Power Transmission and Control, Hangzhou, Beijing: Beijing World Publishing Corporation , 2009, p. 911-918Conference paper (Refereed)
    Abstract [en]

    In this study, a transfer function methodology is employed for mapping simulated internal pump dynamics, such as piston forces and bending moments, on to audible noise. Using these transfer functions, it is possible to predict how, for instance, changed valve plate timing affects simulated piston forces and bending moments and in turn how that will affect audible noise. Hence, it is possible to design an objective function that directly reflects audible noise. The transfer functions are experimentally obtained and are valid for a specific machine shell and to some minor extent the room’s acoustical properties. Simulation of the internal pump dynamics, and optimisations, are carried out using a pump model developed in the simulation tool HOPSAN. The design application is a fixed hydraulic machine of bent axis type with seven pistons. The theory outlined and the method proposed in the paper can also be applied to other types of hydraulic machines. The paper shows how different noise reduction features affect the sound pressure level and also motor mode compared to pump mode.

  • 18.
    Feng, Xiaolong
    et al.
    ABB Corporate Research, Västerås, Sweden.
    Holmgren, Bo
    ABB Corporate Research, Västerås, Sweden.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Evaluation and Optimization of Industrial Robot Families Using Different Kinematic Measures2010In: ASME 2009 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference: Volume 7: 33rd Mechanisms and Robotics Conference, Parts A and B, The American Society of Mechanical Engineers (ASME) , 2010, Vol. 7, no PART B, p. 1047-1057Conference paper (Refereed)
    Abstract [en]

    In this paper, overall manipulability measure and stroke of workspace are proposed and evaluated as design criteria for optimal kinematics design of a family of industrial robots. The object of study is a 6 degree of freedom serial robot manipulator where individual family members (robots) share arms from a common platform. The paper presents a formal mathematical framework where the product family design problem is stated as an optimization problem and where optimization is used to find an optimal product family. The paper illustrates how the proposed kinematic design criteria may be used to support the optimal kinematics design of a family of industrial robots, and it also visualizes the tradeoff between the size of the common platform and the kinematics performance of individual robots. Copyright © 2009 by ASME.

  • 19.
    Feng, Xiaolong
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Machine Design.
    Sander- Tavalley, S.
    Ölvander, Johan
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Machine Design.
    Cycle-based Robot Drive Train Optimization Utilizing SVD Analysis2008In: ASME Design Automation Conference,2007, Las Vegas: ASME , 2008, p. 903-910Conference paper (Refereed)
    Abstract [en]

    Designing a drive train for an industrial robot is a demanding task where a set of design variables need to be determined so that optimal performance is obtained for a wide range of different duty cycles. The paper presents a method where singular value decomposition (SVD) is used to reduce the design variable set. The application is a six degree of freedom serial manipulator, with nine drive train parameters for each axis and the objective is to minimize the cycle time on 122 representative design cycles without decreasing the expected lifetime of the robot. The optimization is based on a simulation model of the robot and conducted on a reduced set of the initial duty cycles and with the design variables suggested by the SVD analysis. The obtained design reduces the cycle time with 1.6% on the original design cycles without decreasing the life time of the robot.

  • 20.
    Feng, Xiaolong
    et al.
    ABB Corporate Research, Västerås, Sweden.
    Wäppling, Daniel
    ABB Robotics, Västerås, Sweden.
    Andersson, Hans
    ABB Corporate Research, Västerås, Sweden.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Tarkian, Mehdi
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Multi-Objective Optimization in Industrial Robotic Cell Design2010In: ASME 2010 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference: Volume 1: 36th Design Automation Conference, Parts A and B, The American Society of Mechanical Engineers (ASME) , 2010, Vol. 1, p. 815-823Conference paper (Refereed)
    Abstract [en]

    It has become a common practice to conduct simulation-based design of industrial robotic cells, where Mechatronic system model of an industrial robot is used to accurately predict robot performance characteristics like cycle time, critical component lifetime, and energy efficiency. However, current robot programming systems do not usually provide functionality for finding the optimal design of robotic cells. Robot cell designers therefore still face significant challenge to manually search in design space for achieving optimal robot cell design in consideration of productivity measured by the cycle time, lifetime, and energy efficiency. In addition, robot cell designers experience even more challenge to consider the trade-offs between cycle time and lifetime as well as cycle time and energy efficiency. In this work, utilization of multi-objective optimization to optimal design of the work cell of an industrial robot is investigated. Solution space and Pareto front are obtained and used to demonstrate the trade-offs between cycle-time and critical component lifetime as well as cycle-time and energy efficiency of an industrial robot. Two types of multi-objective optimization have been investigated and benchmarked using optimal design problem of robotic work cells: 1) single-objective optimization constructed using Weighted Compromise Programming (WCP) of multiple objectives and 2) Pareto front optimization using multi-objective generic algorithm (MOGA-II). Of the industrial robotics significance, a combined design optimization problem is investigated, where design space consisting of design variables defining robot task placement and robot drive-train are simultaneously searched. Optimization efficiency and interesting trade-offs have been explored and successful results demonstrated.

  • 21.
    Gavel, Hampus
    et al.
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Andersson (Ölvander), Johan
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Johansson (Lundén), Björn
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    An Algorithmic Morphology Matrix for Aircraft Fuel System Design2006In: 25th Congress of the International Council of the Aeronautical Sciences, Hamburg, Germany, 2006, no ICAS-2006-9.2.2Conference paper (Refereed)
  • 22.
    Gavel, Hampus
    et al.
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Krus, Petter
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Andersson (Ölvander), Johan
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Johansson (Lundén), Björn
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Probabilistic design in the conceptual phase of an aircraft fuel system2005In: 7th AIAA Non-Deterministic Design Forum, Austin, USA, 2005, no AIAA-2005-2219Conference paper (Refereed)
  • 23.
    Gavel, Hampus
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology. Saab Aerospace, Sweden.
    Lantto, Birgitta
    Saab Aerospace, Sweden.
    Ellström, Hans
    Saab Aerospace, Sweden.
    Jareland, Martin
    Saab Aerospace, Sweden.
    Steinkellner, Sören
    Linköping University, Department of Management and Engineering. Linköping University, The Institute of Technology.
    Krus, Petter
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Andersson (Ölvander), Johan
    Linköping University, Department of Management and Engineering. Linköping University, The Institute of Technology.
    Strategy for Modeling of large A/C fluid systems2004In: World Aviation Congress and Display, WAC-04, SAE Technical Paper 2004-01-3093, 2004, p. 1495-1506Conference paper (Refereed)
    Abstract [en]

    There is an ongoing trend in the European Military a/c industry towards cooperation between nations when purchasing and between manufacturers when developing and producing a/c. Different manufacturers at different locations develop different parts or sub-systems. When using this approach a vital part of a fast and precise system evaluation is the use of simulation models. In order to stay competitive it is not only sufficient to be able to build large simulation models but also to do it fast.

    This paper describes the conclusions regarding a modelling strategy of large fluid systems drawn from the building of a simulation model of the JAS 39 Gripen fuel system. An overall process is suggested into which the activities of building a model are fitted. This is however not the main objective; it is more important to identify the different issues and activities at the engineering level. If these are properly dealt with, the model development time will be reduced, if not, the wrong model may be designed. "Wrong" here means a model that does not do the job, or solves a problem other than the one intended by the stakeholder.

  • 24.
    Gavel, Hampus
    et al.
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Ölvander Andersson, Johan
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Johansson Lundén, Björn
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Krus, Petter
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Aircraft fuel system synthesis aided by interactive morphology and optimization2007In: 45th AIAA Aerospace Sciences Meeting and Exhibit, Reno, USA, Reno,USA: AIAA , 2007, no AIAA-2007-0653Conference paper (Refereed)
  • 25.
    Gavel, Hampus
    et al.
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Ölvander (Andersson), Johan
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Krus, Petter
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Optimal Conceptual Design of Aircraft Fuel Transfer Systems2006In: Journal of Aircraft, ISSN 0021-8669, Vol. 43, no 5, p. 1334-1340Article in journal (Refereed)
    Abstract [en]

     

    This paper describes early considerations that have to be made when designing an aircraft fuel system. Emphasis is placed on illustrating the impact of top-level aircraft requirements on low-level practicalities such as fuel system design. Choosing between concepts is one of the most critical parts of any design process. Different concepts have different advantages, and the concept that is the best choice is often dependent on the top-level requirements. This paper shows how optimization has been used successfully at Saab Aerospace as a tool that supports concept selection. The example studied is the design of a fuel transfer system for a ventral drop tank and the optimization results in different conceptual designs depending on the top-level requirements.

     

  • 26.
    Gavel, Hampus
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    A quantified and interactive relationship matrix applied to aircraft fuel system conceptual design2010In: International Review of Aerospace Engineering (IREASE), ISSN 1973-7459, E-ISSN 1973-7440, Vol. 3, no 1, p. 9-18Article in journal (Refereed)
    Abstract [en]

    This paper describes how the House of Quality matrix has been quantified for use in conceptual design. The House of Quality matrix is used for visualizing the relationships between subsystem design parameters and top-level requirements. The idea is then to insert quantified values of the subsystems’ characteristics as coupling elements, thus visualizing both the requirements-subsystems relationship and system performance. Here, a spreadsheet program (MS Excel) with a built-in modeling/solver tool has been used to model the subsystems. This makes the matrix interactive, thus facilitating trade studies between requirements and system design. By adding probabilistic analysis it is possible to explore the entire range of system behavior early on, rather than just focusing on one or more worst case scenarios as has previously often been the case, and thus promoting the selection of more optimal solutions. The quantitative approach also opens up for mathematically formal optimization which has been exploited by deriving Pareto fronts for visualization of conflicting objectives, one such objective being. The design application used as illustrative example is conceptual design of an aircraft fuel system.

  • 27.
    Gavel, Hampus
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Machine Design .
    Ölvander, Johan
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Machine Design .
    Krus, Petter
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Machine Design .
    A quantified relationship matrix aided by optimization and probabilistic design2008In: 26th Congress of the International Council of the Aeronautical Sciences,2008, Anchorage: ICAS , 2008Conference paper (Refereed)
  • 28.
    Gopinath, Varun
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, Faculty of Science & Engineering.
    Johansen, Kerstin
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, Faculty of Science & Engineering.
    Andersson (Ölvander), Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, Faculty of Science & Engineering.
    Risk Assessment for Collaborative Operation: A Case Study on Hand-Guided Industrial Robots2018In: Risk Assessment / [ed] Valentina Svalova, InTech, 2018Chapter in book (Refereed)
    Abstract [en]

    Risk assessment is a systematic and iterative process, which involves risk analysis, where probable hazards are identified, and then corresponding risks are evaluated along with solutions to mitigate the effect of these risks. In this article, the outcome of a risk assessment process will be detailed, where a large industrial robot is used as an intelligent and flexible lifting tool that can aid operators in assembly tasks. The realization of a collaborative assembly station has several benefits, such as increased productivity and improved ergonomic work environment. The article will detail the design of the layout of a collaborative assembly workstation, which takes into account the safety and productivity concerns of automotive assembly plants. The hazards associated with hand-guided collaborative operations will also be presented.

  • 29.
    Gopinath, Varun
    et al.
    Linköping University, Department of Management and Engineering, Machine Design.
    Tarkian, Mehdi
    Linköping University, Department of Management and Engineering, Machine Design.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design.
    Gaziza, William
    TEMPLATE DRIVEN CONCEPTUAL DESIGN OF HIGH SPEED TRAINS2014In: Proceedings of the ASME 2014 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference: 40th Design Automation Conference, Buffalo, New York, USA, 2014, Vol. 2AConference paper (Refereed)
  • 30.
    Hallberg, Peter
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Hands-On Assessment During Computer Aided Engineering Education2013In: ASME 2012 International Mechanical Engineering Congress and Exposition: Volume 5, The American Society of Mechanical Engineers (ASME) , 2013, Vol. 5, p. 121-130Conference paper (Refereed)
    Abstract [en]

    This contribution discusses aspects and benefits from involving physical representations when teaching engineering design and Computer Aided Engineering at Linköping University, Sweden.

    The paper presents a syllabus for a comprehensive introductory CAD course. The course is populated by some 300 students on the Mechanical Engineering Master’s and Bachelor’s programs, as well as the Design and Product Development Master’s program. Assessment is made via a project where the students are assigned to model and optimize a small catapult. The catapult is then produced, using cheap materials, by the hands of the students who modeled it. Finally, the catapult is validated by entering a contest, where it is judged in respect of accuracy, weight, and cost. The catapult assignment is constructed in such a way that the students are forced to seek individual ways of applying their newly acquired knowledge of the CAD tool. Some 100 catapults are produced but the material cost for each catapult is only about €4.

    The low-cost nature of the catapults originates from research conducted at the Division of Machine Design at Linköping University, where the concept of Low-cost Demonstrators for enhancement of the conceptual design phase has been developed over the past decade. The results from this research point towards several benefits from using physical representations alongside the common digital tools during the early stages of the product development process. Furthermore, evaluation of parameters such as the students’ performance and their own opinions of the course show notable enhancement compared to previous courses.

  • 31.
    Johansson, Andreas
    et al.
    Parker Hannifin, Sweden.
    Ölvander, Johan
    Linköping University, Department of Mechanical Engineering. Linköping University, The Institute of Technology.
    Palmberg, Jan-Ove
    Linköping University, Department of Mechanical Engineering. Linköping University, The Institute of Technology.
    Experimental verification of cross-angle for noise reduction in hydraulic piston pumps2007In: Proceedings of the Institution of mechanical engineers. Part I, journal of systems and control engineering, ISSN 0959-6518, E-ISSN 2041-3041, Vol. 221, no 3, p. 321-330Article in journal (Refereed)
    Abstract [en]

    One of the most important drawbacks with hydraulic systems is noise and vibration, which mainly originate from the hydrostatic pump. A great number of noise-reducing design features have been developed, but they are all, to a greater or lesser extent, sensitive to variations in operational conditions. The present paper is concerned with optimal design and experimental verification of the cross-angle in an axial piston pump. The cross-angle is a small fixed incline of the swash plate in the direction that is perpendicular to the traditional displacement direction. It enables effective noise reduction throughout the whole range of displacement angles.

    Simulation-based optimization is used to design a pump with optimal cross-angle and a matching valve plate. The design is manufactured and experimentally evaluated. Source flow measurements using the two-microphone method show good agreement between simulation and experiments, which verifies the applicability of the simulation model used. The benefits from using the cross-angle are then verified by comparing it with a pump with a traditional swash plate design, i.e. without the cross-angle. Both source flow measurements and sound level measurements in an anechoic chamber show good improvements from using the cross-angle.

  • 32.
    Johansson, Cristina
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology. Saab Aeronautics, Linköping, Sweden.
    Persson, Per
    Saab Aeronautics, Linköping, Sweden.
    Derelöv, Michael
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Choosing the reliability approach: A guideline for selecting the appropriate reliability method in the design process2013In: Proceedings of the 20th Advances in Risk and Reliability Technology Symposium 21–23 May 2013 / [ed] Lisa Jackson and John Andrews, Loughborough: Loughborough University, UK , 2013, p. 366-378Conference paper (Other academic)
    Abstract [en]

    The main objective of a reliability study should always be to provide information as a basis for decisions, e.g. concept choice, design requirements, investment, choice of suppliers, design changes or guaranty claims. The choice of reliability method depends on the time allocated for the reliability study, the design stage, the problem at hand and the competence and resources available.

    During a reliability study the engineer focuses on providing a graphical means of evaluating the relationships between different parts of the system, gathering or assessing the reliability data for the components and interpreting the results of the analyses. Even though the commercial software tools available claim to provide answers to most reliability questions, choosing which method is best suited is not an easy task. Often several methods can be applied and none of them will fit the purpose perfectly.

    This paper presents a guideline for choosing the best suited reliability method in early design phases from two aspects: objective and system characteristics. The methods studied are the most common methods available in commercial software tools: Reliability Block Diagram (RBD), Fault Tree (FT), Event Tree (ET), Markov Analysis (MA) and Stochastic Petri Network (SPN). The guideline considers two aspects: the characteristics of the system studied and the scope of the analysis. The applicability of each of the five chosen methods is assessed for all possible combinations of system characteristics and objective. A study has been made at Saab Aeronautics to evaluate the practical use of the analysed methods and how this guideline can improve the selection of appropriate reliability methods in early design phases.

  • 33.
    Johansson, Cristina
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology. Saab Aeronautics, Linköping, Sweden.
    Persson, Per
    Saab Aeronautics, Linköping, Sweden.
    Derelöv, Michael
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Cost optimization with focus on reliability and system safety2013In: Safety, Reliability and Risk AnalysisBeyond the Horizon / [ed] R. D. J. M. Steenbergen , P. H. A. J. M. van Gelder , S. Miraglia and A. C. W. M. Ton. Vrouwenvelder, CRC Press, 2013, p. 2723-2730Conference paper (Refereed)
    Abstract [en]

    When developing a safety critical system, there are many aspects that need to be balanced against each other in order to reach an optimal design such as safety requirements, reliability goal, performance specifications and budget constraints. In an early design stage, it is vital to be able to screen the design space for a set of promising design alternatives for further studies. This paper proposes an approach capable of investigating the trade-offs described above, combining the techniques for system safety and reliability analysis with optimization methods. Markov analysis is employed for modeling the system safety and reliability characteristics and a Genetic Algorithm is used for optimization. The proposed method is applied to the design of an electric supply system for an aircraft, involving selection of components from different suppliers. First a model is built for each objective, i.e. cost, safety, and reliability. The models are validated and optimization is performed. The obtained result is the selection of suppliers for each component in the system in order to achieve a balance between system safety, reliability, and other design objectives.

  • 34.
    Johansson, Cristina
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology. Saab Aeronautics, Linköping, Sweden.
    Persson, Per
    Saab Aeronautics, Linköping, Sweden.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    On the Usage of Reliability Methods in Early Design Phases2012In: Proceedings of the 11th International Probabilistic Safety Assessment and Management Conference and the Annual European Safety and Reliability Conference 2012 (PSAM11 ESREL 2012), Curran Associates, Inc., 2012, p. 769-778Conference paper (Refereed)
    Abstract [en]

    One important challenge in the early phases of product development is to apply reliability methods for estimating the safety and reliability of the system when information about the chosen equipment and components is limited. For systems consisting of units with several degraded states, and not only “up” and “down”, the results from reliability and system safety analysis are often difficult to interpret and use. The main contribution of this paper is to evaluate the applicability of different reliability methods for analyzing an overall system concept in early development stages. Furthermore, the paper constitutes the first step of a methodology intended to address the issues outlined above from a practical point of view. In the paper, two static methods, Reliability Block Diagram and Fault Tree Analysis, and one dynamic method, Markov Analysis, have been applied to conceptual design of an aircraft electrical system. These three methods have been evaluated regarding usefulness, modeling possibilities and applicability in the conceptual design. Each method is, from a practical point of view, dependent on the limitations of the software that is used. In order to overcome this issue the calculations and partly the modeling have been performed in three different software tools.

    Two iterations have been performed for Markov Analysis, and the results are used to evaluate the method regarding applicability and possibilities of modeling the system and to find out what results can be gained by extending the model.

  • 35.
    Krus, Petter
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Machine Design.
    Ölvander, Johan
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Machine Design .
    An Information Theoretical Perspective on Design Optimizartion2004In: 2004 DETC:Design Engineering Technical Conference,2004, 2004Conference paper (Refereed)
  • 36.
    Krus, Petter
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Machine Design.
    Ölvander, Johan
    Linköping University, Department of Mechanical Engineering.
    Optimizing Optimization for Design Optimization2003In: Design Engineering Technical Conferences and Computers and Information in Engineering Conference,2003, New York: ASME Press , 2003Conference paper (Refereed)
    Abstract [en]

    Design optimization is becoming and increasingly important tool for design. In order to have an impact on the product development process it must permeate all levels of the design in such a way that a holistic view is maintained through all stages of the design. One important area is in the case of optimization based on simulation, which generally requires non-gradient methods and as a consequence direct-search methods is a natural choice. The idea in this paper is to use the design optimization approach in the optimization algorithm itself in order to produce an efficient and robust optimization algorithm. The result is a single performance index to measure the effectiveness of an optimization algorithm, and the COMPLEX-RF optimization algorithm, with optimized parameters.

  • 37.
    Krus, Petter
    et al.
    Linköping University, Department of Management and Engineering, Fluid and Mechatronic Systems. Linköping University, The Institute of Technology.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Performance index and meta-optimization of a direct search optimization method2013In: Engineering optimization (Print), ISSN 0305-215X, E-ISSN 1029-0273, Vol. 45, no 10, p. 1167-1185Article in journal (Refereed)
    Abstract [en]

    Design optimization is becoming an increasingly important tool for design, often using simulation as part of the evaluation of the objective function. A measure of the efficiency of an optimization algorithm is of great importance when comparing methods. The main contribution of this article is the introduction of a singular performance criterion, the entropy rate index based on Shannon's information theory, taking both reliability and rate of convergence into account. It can also be used to characterize the difficulty of different optimization problems. Such a performance criterion can also be used for optimization of the optimization algorithms itself. In this article the Complex-RF optimization method is described and its performance evaluated and optimized using the established performance criterion. Finally, in order to be able to predict the resources needed for optimization an objective function temperament factor is defined that indicates the degree of difficulty of the objective function.

  • 38.
    Krus, Petter
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Machine Design.
    Ölvander, Johan
    Linköping University, Department of Mechanical Engineering.
    Simulation Based Optimisation for Aircraft Systems2004In: SAE Transactions Journal of Aerospace, Vol. 2003, p. 445-453Article in journal (Refereed)
    Abstract [en]

    Modelling and simulation is of crucial importance for system design and optimisation. In aeronautics, simulation has been strong in the area of flight dynamics and control. Modelling and simulation of basic aircraft systems such as hydraulic systems also has a long tradition, and the rapid increase in computational power has now come to a point where complete modelling and simulation of all the sub systems in an aircraft is possible. There are several levels of design from requirement analysis and system architecture down to detail design, and there is a clear danger that systems engineering activities are performed only at the top level of a design. In order to have an impact on the product development process it must permeate all levels of the design in such a way that a holistic view is maintained through all stages of the design. This can be achieved if all design teams can work towards a common system model where the subsystem designs can be tested in an environment where the interaction with other sub-system and the whole aircraft can be studied. In this paper it is discussed how the actuation system control surfaces can be simulated and optimised using a flight dynamics model of the aircraft coupled to a model of the actuation system. In this way the system can be optimised for certain flight condition by "test flying- the system. The distributed modelling approach used, makes it possible to simulate this system much faster than real time on a 650 MHz PC. This means that even system optimisation can be performed in reasonable time.

  • 39.
    Krus, Petter
    et al.
    Linköping University, Department of Management and Engineering, Fluid and Mechatronic Systems. Linköping University, Faculty of Science & Engineering.
    Ölvander, johan
    Linköping University, Department of Management and Engineering, Fluid and Mechatronic Systems. Linköping University, Faculty of Science & Engineering.
    Rydberg, Karl-Erik
    Linköping University, Department of Management and Engineering, Fluid and Mechatronic Systems. Linköping University, Faculty of Science & Engineering.
    Drive Train Concept Selection for Industrial Robots2011Conference paper (Other academic)
  • 40.
    Lundén Johansson, Björn
    et al.
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Pettersson, Marcus
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Ölvander (Andersson), Johan
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    A Component Based Optimization Approach for Robot Modular Design2007In: Proceedings of DETC'2007 ASME Design Automation Conference, September, Las Vegas, Nevada, USA, 2007Conference paper (Other academic)
  • 41.
    Mandl, Clemens
    et al.
    University of Applied Sciences Technikum Wien, Vienna, Austria.
    Feng, Xiaolong
    ABB Corporate Research, Västerås, Sweden.
    Ölvander, Johan
    Linköping University, Department of Mechanical Engineering, Machine Design. Linköping University, The Institute of Technology.
    Automated Design of an Industrial Robot Family2009In: ASME 2009 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference: Volume 5: 35th Design Automation Conference, Parts A and B, New York, NY, USA: American Society of Mechanical Engineers, ASME , 2009, p. 927-939Conference paper (Refereed)
    Abstract [en]

    In this work, a methodology and an integrated tool framework has been developed for automated design of an industrial robot family consisting of four robot members. For each robot, performance requirements concerning payloads, reaches, and time performances are specified. A 3D design tool, namely Solid Works, has been integrated with robot kinematics and dynamics simulation tools for simultaneous kinematics and dynamics design. A motor library comprising both geometric data and physical data has also been integrated in the tool framework. The automated design of the robot family has been formulated as a multi-objective and mixed variable design optimization problem. The arm modules are treated as continuous design variables while the motors are treated as discrete variables. Due to the characteristics of this mixed variable design optimization problem a genetic algorithm (GA) has been used. This work has successfully demonstrated the feasibility for achieving automatic design of an industrial robot family.

  • 42.
    Papageorgiou, Athanasios
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, Faculty of Science & Engineering.
    Tarkian, Mehdi
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, Faculty of Science & Engineering.
    Amadori, Kristian
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, Faculty of Science & Engineering.
    Andersson (Ölvander), Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, Faculty of Science & Engineering.
    Multidisciplinary Optimization of Unmanned Aircraft Considering Radar Signature, Sensors, and Trajectory Constraints2018In: Journal of Aircraft, ISSN 0021-8669, E-ISSN 1533-3868, Vol. 55, no 4, p. 1629-1640Article in journal (Refereed)
    Abstract [en]

    This paper presents a multidisciplinary design optimization framework applied to the development of unmanned aerial vehicles with a focus on radar signature and sensor performance requirements while simultaneously considering the flight trajectory. The primary emphasis herein is on the integration and development of analysis models for the calculation of the radar cross section and sensor detection probability, whereas traditional aeronautical disciplines such as aerodynamics and mission simulation are also taken into account in order to ensure a flyable concept. Furthermore, this work explores the effect of implementing trajectory constraints as a supplementary input to the multidisciplinary design optimization process and presents a method that enables the optimization of the aircraft under a three-dimensional flight scenario. To cope with the additional computational cost of the high-fidelity radar cross section and sensor calculations, the use of metamodels is also investigated and an efficient development methodology that can provide high-accuracy approximations for this particular problem is proposed. Overall, the operation and performance of the framework are evaluated against five surveillance scenarios, and the obtained results show that the implementation of trajectory constraints in the optimization has the potential to yield better designs by 12–25% when compared to the more “traditional” problem formulations.

  • 43.
    Persson, Johan
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Feng, X.
    ABB Corporate ResearchVästerås, Sweden.
    Wappling, D.
    ABB Corporate ResearchVästerås, Sweden.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Multi-disciplinary and multi-objective optimization of a hydro-pneumatic balancing cylinder for an industrial robot2014In: ASME 2014 12th Biennial Conference on Engineering Systems Design and Analysis, ESDA 2014, Web Portal ASME (American Society of Mechanical Engineers) , 2014, Vol. 3Conference paper (Refereed)
    Abstract [en]

    This article presents an optimization framework that is used to optimize a hydro-pneumatic balancing cylinder for industrial robots. A balancing cylinder is a device that is used to balance the gravitational torque of one of the main axes of a high-loaded serial industrial robot. The design of components for an industrial robot is multi-disciplinary, since disciplines such as multibody dynamics, drive train design and robot control are needed. The design process is also multi-objective since the functionality of the balancing cylinder should be optimal, while its size and cost should be minimal. The article therefore also contains a discussion about multi-disciplinary and multi-objective optimization of complex products.

  • 44.
    Persson, Johan
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Feng, Xiaolong
    ABB Corporate Research Västerås, Sweden.
    Wappling, Daniel
    ABB Corporate Research Västerås, Sweden.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    A Framework for Multidisciplinary Optimization ofa Balancing Mechanism for an Industrial Robot2015In: Journal of Robotics, ISSN 1687-9600, E-ISSN 1687-9619, p. 1-8, article id 389769Article in journal (Other academic)
    Abstract [en]

    The paper presents a framework that can be used to design and optimize a balancing mechanism for an industrial robot. The framework has the capability to optimize three different concepts - a mechanical, a pneumatic and a hydro-pneumatic. Several disciplines are included in the framework, such as dynamic and static analyses of the robot performance. Optimization is performed for each concept and the obtained optimal designs are all better then the reference design. This means that the framework can be used both as a tool to optimize the balancing mechanism and also to support concept selection.

  • 45.
    Persson, Johan
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    A Modified Complex Algorithm Applied to Robust Design Optimization2011In: 13th AIAA Non-Deterministic Approaches Conference, 2011, p. 2011-2095Conference paper (Refereed)
    Abstract [en]

    Today there is a desire to perform optimizations in order to receive optimal system properties. However, for computationally expensive simulation models, an optimization maybe too tedious to be motivated. This paper proposes a modification of the Complexoptimization algorithm to enable the creation and usage of local meta-models during theoptimization. Its performance is demonstrated for a few analytical problems and a reliabilitybased design optimization is conducted for an aircraft example.

  • 46.
    Persson, Johan
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Comparison of Different Uses of Metamodels for Robust Design Optimization2013Conference paper (Other academic)
    Abstract [en]

    This paper compares different approaches for using kriging metamodels for robust design optimization, with the aim of improving the knowledge of the performance of the approaches. A popular approach is to first fit a metamodel to the original model and then perform the robust design optimization on the metamodel. However, it is also possible to create metamodels during the optimization. Additionally, the metamodel need not necessarily reanimate the original model; it may also model the mean value, variance or the actual objective function. The comparisons are made with two analytical functions and a dynamic simulation model of an aircraft system as an engineering application. In the comparisons, it is seen that creating a global metamodel before the optimization begins slightly outperforms the other approaches that involve metamodels.

  • 47.
    Persson, Johan
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Comparison of Sampling Methods for a Dynamic Pressure Regulator2011In: 49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, AIAA American Institute of Aeronautics and Astronautics , 2011Conference paper (Refereed)
    Abstract [en]

    Concepts for complex products are often developed using computer models, introducinguncertainties both in design and model accuracy. There exist several methods forapproximating these uncertainties and this paper presents and compares some of them. Thefocus is on sampling based methods including or excluding response surfaces, and they arecompared by accuracy and computation time, using a Monte Carlo sampling as reference.The application is a simplified system model of a dynamic pressure regulator that controlsthe air supply in the environmental control system of an aircraft.

  • 48.
    Persson, Johan
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Comparisons of Different Methods for Robust Optimization in Engineering DesignManuscript (preprint) (Other academic)
    Abstract [en]

    This paper compares the performance of five methods for robust design optimization of computationally demanding models including one novel method. The comparison is made using several mathematical functions and two engineering problems. The performance metrics are the mean value and standard deviation of the optimum as well as an index that weights together the required number of simulations of the original model and the chance of finding the optimum. The result of the comparison shows that sequential robust optimization is the most effective method.

  • 49.
    Persson, Johan
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, The Institute of Technology.
    Optimization of the Complex-RFM Optimization Algorithm2015In: Optimization and Engineering, ISSN 1389-4420, E-ISSN 1573-2924, Vol. 16, no 1, p. 27-48Article in journal (Refereed)
    Abstract [en]

    This paper presents and compares different modifications made to the Complex-RF optimization algorithm with the aim of improving its performance for computationally expensive models. The modifications reduces the required number of objective function evaluations by creating and using surrogate models of the objective function iteratively during the optimization process. The chosen surrogate model type is a second order response surface. The performance of the modified algorithm is compared with a number of existing algorithms and demonstrated for a few analytical and engineering problems.

  • 50.
    Pettersson, Marcus
    et al.
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Andersson (Ölvander), Johan
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Krus, Petter
    Linköping University, Department of Management and Engineering, Machine Design . Linköping University, The Institute of Technology.
    Methods for Discrete Design Optimization2005In: Proceedings of ASME 31st Design Automation Conference, September 24-28, Long Beach, USA, 2005Conference paper (Other academic)
    Abstract [en]

    One area in design optimization is component based design where the designer has to choose between many different discrete alternatives. These types of problems have discrete character and in order to admit optimization an interpolation between the alternatives is often performed. However, in this paper a modified version of the non-gradient algorithm the Complex method is developed where no interpolation between alternatives is needed. Furthermore, the optimization algorithm itself is optimized using a performance metric that measures the effectiveness of the algorithm. In this way the optimal performance of the proposed discrete Complex method has been identified. Another important area in design optimization is the case of optimization based on simulations. For such problems no gradient information is available, hence non-gradient methods are therefore a natural choice. The application for this paper is the design of an industrial robot where the system performance is evaluated using comprehensive simulation models. The objective is to maximize performance with constraints on lifetime and cost, and the design variables are discrete choices of gear boxes for the different axes.

12 1 - 50 of 82
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf