liu.seSearch for publications in DiVA
Change search
Refine search result
12 1 - 50 of 94
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.
    Alexandersson, Johan
    et al.
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, Faculty of Science & Engineering.
    Nordin, Olle
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, Faculty of Science & Engineering.
    Implementation of CAN Communication Stack in AUTOSAR2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the automotive industry today, embedded systems have reached a level of complexity which is not maintainable with the traditional approach of design- ing automotive embedded systems. For this purpose, many of the worlds leading automotive manufacturers have formed an alliance to apprehend this problem. This has resulted in AUTOSAR, an open standardized architecture for automotive embedded systems, which strives for increased flexibility and safety regulations. This thesis will explore the possibilities of implementing a CAN Communication stack using the AUTOSAR architecture and its corresponding methodology. As a result of this thesis, a complete AUTOSAR CAN communication stack has been implemented, as well has a simulator application with the purpose of testing its functionality. 

  • 2.
    Andersson, Erik
    et al.
    Linköping University, Department of Electrical Engineering, Electronics System.
    Olsson, Christian
    Linköping University, Department of Electrical Engineering, Electronics System.
    Linearization of Power Amplifier using Digital Predistortion, Implementation on FPGA2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of this thesis is to linearize a power amplifier using digital predistortion. A power amplifier is a nonlinear system, meaning that when fed with a pure input signal the output will be distorted. The idea behind digital predistortion is to distort the signal before feeding it to the power amplifier. The combined distortions from the predistorter and the power amplifier will then ideally cancel each other. In this thesis, two different approaches are investigated and implemented on an FPGA. The first approach uses a nonlinear model that tries to cancel out the nonlinearities of the power amplifier. The second approach is model-free and instead makes use of a look-up table that maps the input to a distorted output. Both approaches are made adaptive so that the parameters are continuously updated using adaptive algorithms. First the two approaches are simulated and tested thoroughly with different parameters and with a power amplifier model extracted from the real amplifier. The results are shown satisfactory in the simulations, giving good linearization for both the model and the model-free technique. The two techniques are then implemented on an FPGA and tested on the power amplifier. Even though the results are not as well as in the simulations, the system gets more linear for both the approaches. The results vary widely due to different circumstances such as input frequency and power. Typically, the distortions can be attenuated with around 10 dB. When comparing the two techniques with each other, the model-free method shows slightly better results.

  • 3.
    Andersson, Isak
    et al.
    Linköping University, Department of Electrical Engineering, Electronics System. Linköping University, The Institute of Technology.
    Karlsson, Melki
    Linköping University, Department of Electrical Engineering, Electronics System. Linköping University, The Institute of Technology.
    Body Coupled Communication: Ändring av prototypkort2014Independent thesis Basic level (university diploma), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    Communication using the human body as a transmission medium, the capacitive coupling between the skin and sensor, has been an active research area for PAN (Personal Area Network) since Thomas Guthrie Zimmerman introduced the technique in 1995. The reason for this is to examine the benefits and uses of a communication method that does not emit RF signals and thus reduce the risk of unauthorized interception.

    This report describes a thesis that examines the possibility of elimination of USB to UART converter on Microchip BodyCom through software USB-stack and combine this with Body Coupled Communication functionality in a single microcontroller. Furthermore, studies on if the application code in Body Coupled Communication transmitters can be modified to extend functionality.

    It was given in the conditions that microcontrollers from Microchip should be used, furthermore, low price and low power consumption were important, especially for the transmitter. The method for achieving this has been the use of Microchip BodyCom development kit with USB Microchip low pin count development kit and Microchip USB firmware framework.

    The result was that the USB- to UART-converter could be integrated with Microchip BodyCom, using software USB-stack and a modified program code for BodyCom in a single microcontroller.

    Only your imagination sets the limits for Body Coupled Communication can be used for. For example, it would be possible to exchange electronic business cards by a handshake or open a locked door only by using the handle.

  • 4.
    Athalye, Akshay
    et al.
    Stony Brook University, USA.
    Savic, Vladimir
    Technical University of Madrid, Spain.
    Bolic, Miodrag
    University of Ottawa, Canada.
    Djuric, Petar M.
    Stony Brook University, USA.
    A Radio Frequency Identification System for accurate indoor localization2011In: Proc. of IEEE Intl. Conf. on Acoustics, Speech and Signal Processing (ICASSP), 2011, p. 1777-1780Conference paper (Refereed)
    Abstract [en]

    In this paper we present a novel Radio Frequency Identification (RFID) system for accurate indoor localization. The system is composed of a standard Ultra High Frequency (UHF), ISO-18006C compliant RFID reader, a large set of standard passive RFID tags whose locations are known, and a newly developed tag-like RFID component that is attached to the items that need to be localized. The new semi-passive component, referred to as sensatag (sense-a-tag), has a dual functionality wherein it can sense the communication between the reader and standard tags which are in its proximity, and also communicate with the reader like standard tags using backscatter modulation. Based on the information conveyed by the sensatags to the reader, localization algorithms based on binary sensor principles can be developed. We present results from real measurements that show the accuracy of the proposed system.

  • 5.
    Athalye, Akshay
    et al.
    Stony Brook University, USA.
    Savic, Vladimir
    Signal Processing Application Group, Universidad Politecnica de Madrid, Madrid, Spain.
    Bolic, Miodrag
    University of Ottawa, Canada.
    Djuric, Petar M.
    Stony Brook University, USA.
    Novel Semi-Passive RFID System for Indoor Localization2013In: IEEE Sensors Journal, ISSN 1530-437X, E-ISSN 1558-1748, Vol. 13, no 2, p. 528-537Article in journal (Refereed)
    Abstract [en]

    In this paper, we present a novel semi-passive radio-frequency identification (RFID) system for accurate indoor localization. The system is composed of a standard ultra high frequency (UHF) ISO-18000-6C compliant RFID reader, a set of standard passive RFID tags whose locations are known, and a newly developed tag-like RFID component, which is attached to the items that need to be localized. The new semi-passive component, referred to as sensatag (sense-a-tag), has a dual functionality: it can sense and decode communication between the reader and standard tags in its proximity, and can communicate with the reader like standard tags using backscatter modulation. Based on the information conveyed by the sensatags to the reader, localization algorithms based on binary sensor principles can be developed. We conduct a number of experiments in a laboratory to quantify the performance of our system, including two real applications, one finding the exact placement of items on shelves, and the other estimating the direction of item movement.

  • 6.
    Bengtsson, Tomas
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Testing and Logic Optimization Techniques for Systems on Chip2012Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Today it is possible to integrate more than one billion transistors onto a single chip. This has enabled implementation of complex functionality in hand held gadgets, but handling such complexity is far from trivial. The challenges of handling this complexity are mostly related to the design and testing of the digital components of these chips.

    A number of well-researched disciplines must be employed in the efficient design of large and complex chips. These include utilization of several abstraction levels, design of appropriate architectures, several different classes of optimization methods, and development of testing techniques. This thesis contributes mainly to the areas of design optimization and testing methods.

    In the area of testing this thesis contributes methods for testing of on-chip links connecting different clock domains. This includes testing for defects that introduce unacceptable delay, lead to excessive crosstalk and cause glitches, which can produce errors. We show how pure digital components can be used to detect such defects and how the tests can be scheduled efficiently.

    To manage increasing test complexity, another contribution proposes to raise theabstraction level of fault models from logic level to system level. A set of system level faultmodels for a NoC-switch is proposed and evaluated to demonstrate their potential.

    In the area of design optimization, this thesis focuses primarily on logic optimization. Two contributions for Boolean decomposition are presented. The first one is a fast heuristic algorithm that finds non-disjoint decompositions for Boolean functions. This algorithm operates on a Binary Decision Diagram. The other contribution is a fast algorithm for detecting whether a function is likely to benefit from optimization for architectures with a gate depth of three with an XOR-gate as the third gate.

  • 7.
    Bengtz, Gustaf
    Linköping University, Department of Electrical Engineering. Linköping University, The Institute of Technology.
    Analysis of new and alternative encryption algorithms and scrambling methods for digital-tv and implementation of a new scrambling algorithm (AES128) on FPGA.2014Independent thesis Advanced level (degree of Master (Two Years)), 300 HE creditsStudent thesis
    Abstract [en]

    This report adresses why the currently used scrambling standard CSA needs a replacement. Proposed replacements to CSA are analyzed to some extent, and an alternative replacement (AES128) is analyzed.

    One alternative being the CSA3, and the other being the CISSA algorithm. Both of the proposed algorithms use the AES algorithm as a base. The CSA3 combines AES128 with a secret cipher, the XRC, while CISSA uses the AES cipher in a feedback mode. The different utilizations makes CSA3 hardware friendly and CISSA software friendly.

    The implementation of the Advanced Encryption Standard (AES) is analyzed for a 128 bit key length based design, and a specific implementation is presented.

  • 8.
    Boudjadar, Abdeldjalil
    et al.
    Computer Science, Aalborg University, Denmark.
    David, Alexandre
    Computer Science, Aalborg University, Denmark.
    Hyun Kim, Jin
    Computer Science, Aalborg University, Denmark.
    Larsen, Kim G.
    Computer Science, Aalborg University, Denmark.
    Mikučionis, Marius
    Computer Science, Aalborg University, Denmark.
    Nyman, Ulrik
    Computer Science, Aalborg University, Denmark.
    Skou, Arne
    Computer Science, Aalborg University, Denmark.
    Statistical and exact schedulability analysis of hierarchical scheduling systems2016In: Science of Computer Programming, ISSN 0167-6423, E-ISSN 1872-7964, Vol. 127, p. 103-130Article in journal (Refereed)
    Abstract [en]

    This paper contains two contributions: 1) A development methodology involving two techniques to enhance the resource utilization and 2) a new generic multi-core resource model for hierarchical scheduling systems.

    As the first contribution, we propose a two-stage development methodology relying on the adjustment of timing attributes in the detailed models during the design stage. We use a lightweight method (statistical model checking) for design exploration, easily assuring high confidence in the correctness of the models. Once a satisfactory design has been found, it can be proved schedulable using the computation costly method (symbolic model checking). In order to analyze a hierarchical scheduling system compositionally, we introduce the notion of a stochastic supplier modeling the supply of resources from each component to its child components in the hierarchy. We specifically investigate two different techniques to widen the set of provably schedulable systems: 1) a new supplier model; 2) restricting the potential task offsets.

    We also provide a way to estimate the minimum resource supply (budget) that a component is required to provide. In contrast to analytical methods, we prove non-schedulable cases via concrete counterexamples. By having richer and more detailed scheduling models this framework, has the potential to prove the schedulability of more systems.

    As the second contribution, we introduce a generic resource model for multi-core hierarchical scheduling systems, and show how it can be instantiated for classical resource models: Periodic Resource Models (PRM) and Explicit Deadline Periodic (EDP) resource models. The generic multi-core resource model is presented in the context of a compositional model-based approach for schedulability analysis of hierarchical scheduling systems.

    The multi-core framework presented in this paper is an extension of the single-core framework used for the analysis in the rest of the paper.

  • 9.
    Brischetto, Mathias
    Linköping University, Department of Electrical Engineering, Vehicular Systems.
    Improved Functionality for Driveability During Gear-Shift: A Predictive Model for Boost Pressure Drop2015Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Automated gear-shifts are critical procedures for the driveline as they are demanded to work as fast and accurate as possible. The torque control of a driveline is especially important for the driver’s feeling of driveability. In the case of gear-shifts and torque control in general, the boost pressure is key to achieve good response and thereby a fast gear-shift.

    An experimental study is carried out to investigate the phenomena of boost pressure drop during gear-shift and gather data for the modelling work. Results confirm the stated fact on the influence of boost pressure drop on gear-shift completion time and also indicate a clear linear dependence between initial boost pressure and the following pressure drop.

    A dynamic predictive model of the engine is developed with focus on implementation in a heavy duty truck, considering limitations computational complexity and calibration need between truck configurations. The resulting approach is based on a mean value modelling scheme that uses engine control system parameters and functions when possible. To be able to be predictive, a model for demanded torque and engine speed during the gear-shift is developed as reference inputs to the simulation. The simulation is based on a filling and emptying process throughout the engine dynamics, and yields final values of several engine variables such as boost pressure.

    The model is validated and later evaluated in comparison to measurements gathered in test vehicle experiments and in terms of robustness to input and model deviations. Computer simulations yield estimations of the boost pressure drop within acceptable limits. Consid- ering estimations used prior to this thesis the performance is good. Input deviations and modelling inaccuracies are found to inflict significant but not devastating deviations to the model output, possibly more over time with ageing of hardware taken into account.

    Final implementation in a heavy duty truck ecu is carried out with results indicating that the current implementation of the module is relatively computationally heavy. At the time of ending the thesis it is not possible to analyse its performance further, and it is suggested that the module is optimized in terms of computational efficiency. 

  • 10.
    Chan, Chun-Jung
    Linköping University, Department of Electrical Engineering.
    Investigation of NoGap: SIMD Datapath Implementation2011Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Nowadays, many ASIP systems with high computational capabilities are designed in order to fulfill the increasing demands of technical applications. However, the design of ASIP system usually takes many man hours. Therefore, a number of EDA tools are developed to ease the design effort, but they limit the design freedom due to their predefined design templates. Consequently, designers are forced to use lower level HDLs which offer high design flexibility but require substantial design hours. A novel design automation tool called NoGap was proposed to balance such issues. The NoGap system, which is especially used in ASIPs and accelerator design, effectively provides high design flexibility and saves design effort for designers.

    The efficiency and design ability of NoGap were investigated in this thesis work. NoGap was used to implement an eight-way SIMD datapath of an ASIP called Sleipnir, which was devised by the Division of Computer Engineering at Linköping University. For contrast, the manually crafted HDL implementation of the Sleipnir was taken. The critical path implementations, done by both design approaches, were synthesized to the Altera Strtix IV FPGA. The synthesize results showed that the NoGap design although used 1.358 times as many hardware units as the original HDL design. Their timing performance is comparable (HDL/NoGap-60.042/58.156Mhz).

    In this thesis, based on the design experience of SIMD datapath, valuable aspects were suggested to benefit the future users who will use NoGap to implement SIMD structures. In addition, the hidden bugs and insufficient features of NoGap were discovered, and the referable suggestions were provided in order to help the developers to improve the NoGap system.

  • 11.
    Cuello, Rosandra
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Providing Support for the Movidius Myriad1 Platform in the SkePU Skeleton Programming Framework2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Movidius Myriad1 Platform is a multicore embedded platform primed to offer high performance and power efficiency for computer vision applications in mobile devices. The challenges of programming multicore environments are well known and skeleton programming offers a high-level programming alternative for parallel computing, intended to hide the complexities of the system from the programmer. The SkePU Skeleton Programming Framework includes backend implementations for CPU and GPU systems and it has the capacity to support more platforms by extending its backend implementations. With this master thesis project we aim to extend the SkePU Skeleton Programming Framework to provide support for execution in the Movidius Myriad1 embedded platform. Our SkePU backend for Myriad1 consists on a set of macros and functions to compose the different elements of a Myriad1 application, data communication structures to exchange data between the host systems and Myriad1, and a helper script and auxiliary files to generate a Myriad1 application.Evaluation and testing demonstrate that our backend is usable, however further optimizations are needed to obtain good performance that would make it practical to use in real life applications, particularly when it comes to data communication. As part of this project, we have outlined some improvements that could be applied to obtain better performance overall in the future, addressing the issues found with the methods of data communication.

  • 12.
    Danielsson, Per-Erik
    Linköping University, Department of Electrical Engineering. Linköping University, The Institute of Technology.
    Implementations of the Convolution Operation1982Report (Other academic)
    Abstract [en]

    The first part of this article surveys a large number of implementations of the convolution operation (which is also known as the sum-of-products, the inner product) based on a systematic exploration of index permutations. First we assume a limited amount of parallelism in the form of an adder. Next, multipliers and RAM:s are utilized. The so called distributed arithmetic follows naturally from this approach.

    The second part brings in the concept of pipelining on the bitlevel to obtain high throughput convolvers adapted for VLSI-design (systolic arrays). The serial/parallel multiplier is analyzed in a way that unravels a vast amount new variations. Even more interesting, all these new variations can be carried over to serial/parallel convolvers. These novel devices can be implemented as linear structures of identical cells where the multipliers are embedded at equidistant intervals.

  • 13.
    Di Orio, Giovanni
    et al.
    Dept. of Electrotechnical Engineering CTS – UNINOVA, Portugal.
    Rocha, Andre
    Dept. of Electrotechnical Engineering CTS – UNINOVA, Portugal.
    Ribeiro, Luis
    Linköping University, Department of Management and Engineering, Manufacturing Engineering. Linköping University, Faculty of Science & Engineering.
    Barata, Jose
    Dept. of Electrotechnical Engineering CTS – UNINOVA, Portugal.
    The PRIME Semantic Language: Plug and Produce in Standard- based Manufacturing Production Systems2015In: Proceedings of the Flexible Automation and Intelligent Manufacturing Conference, 2015Conference paper (Other academic)
    Abstract [en]

    Nowadays manufacturing production systems are becoming more and more responsive in order to succeed in ahighly unstable environment. The capability of a production system to effectively and efficiently adapt and evolveto face the changing requirements – imposed by volatile and dynamic global markets – is a necessary conditionto enable manufacturing enterprises to be agile. Since the agility of a manufacturing enterprise is always limitedby the agility of its own building blocks than it needs to be spread over the whole enterprise including the operationand information technologies (OT/IT). Turning to production systems, one of the significant challenges isrepresented by the possibility to provide easy and rapid (re-)configuration of their internal components and/orprocesses. Innovative technologies and paradigms have been explored during the years that combined with theincreasing advancement in manufacturing technologies enable the implementation of the “plug and produce”paradigm. The “plug and produce” paradigm is the foundation of any agile production system, since to be agile itis inevitably required to reduce the installation and (re-)engineering activities time – changing/adapting the systemto new requirements – while promoting configuration rather than programming. Therefore, the “plug andproduce” paradigm is a necessary but not sufficient condition for implementing agile production systems. Modernproduction systems are typically known for their plethora of heterogeneous component/equipment. In this complexscenario, the implementation of the “plug and produce” paradigm implies the existence of a well-definedontological model to support components/equipment abstraction with the objective to allow interactions,collaboration and knowledge sharing between them. The PRIME semantic language specifies the semanticstructure for the knowledge models and overall system communication language.

  • 14.
    Ehliar, Andreas
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, The Institute of Technology.
    Area Efficient Floating-Point Adder and Multiplier with IEEE-754 Compatible Semantics2014Conference paper (Refereed)
    Abstract [en]

    In this paper we describe an open source floating-point adder andmultiplier implemented using a 36-bit custom number format based onradix-16 and optimized for the 7-series FPGAs from Xilinx. Althoughthis number format is not identical to the single-precision IEEE-754format, the floating-point operators are designed in such a way thatthe numerical results for a given operation will be identical to theresult from an IEEE-754 compliant operator with support forround-to-nearest even, NaNs and Infs, and subnormalnumbers. The drawback of this number format is that the rounding stepis more involved than in a regular, radix-2 based operator. On theother hand, the use of a high radix means that the area costassociated with normalization and denormalization can be reduced,leading to a net area advantage for the custom number format, underthe assumption that support for subnormal numbers is required.

    The area of the floating-point adder in a Kintex-7 FPGA is 261 sliceLUTs and the area of the floating-point multiplier is 235 slice LUTsand 2 DSP48E blocks. The adder can operate at 319 MHz and themultiplier can operate at a frequency of 305 MHz.

  • 15.
    Ehliar, Andreas
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, The Institute of Technology.
    EBRAM - Extending the BlockRAMs in FPGAs to support caches and hash tables inan efficient manner2012Conference paper (Refereed)
    Abstract [en]

    In this paper we discuss how a typical Block RAM in an FPGA can be extended to enable the implementation of more efficient caches in FPGAs with very minor modifications to the existing Block RAM architectures. In addition, the modifications also allow other components, such as hash tables, to be implemented more efficiently.

  • 16.
    Ehliar, Andreas
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, The Institute of Technology.
    Optimizing Xilinx designs through primitive instantiation2010In: FPGAworld '10 Proceedings of the 7th FPGAworld Conference, New York: ACM , 2010, p. 20-27Conference paper (Refereed)
    Abstract [en]

    This paper is intended as a guideline for people who are interested in manual instantiation of FPGA primitives as a way of improving the performance of an FPGA design. The focus of the paper is on designs where slice primitives like flip-fops and lookup tables are instantiated. Guidelines on how to develop a design with manual instantiation are presented together with a case study of a high performance bitserial two's complement divider where a majority of the area is manually instantiated. This divider is capable of reaching a maximum frequency of 345 MHz in the fastest Virtex-4 while utilizing less than 150 LUTs thanks to the high amount of manual optimizations. An open source library containing modules intended to promote the structured development of modules with manually instantiated components is also presented.

  • 17.
    Ehliar, Andreas
    et al.
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, The Institute of Technology.
    Siverskog, Jacob
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, The Institute of Technology.
    Using Partial Reconfigurability to aid Debugging of FPGA Designs2011Conference paper (Refereed)
    Abstract [en]

    This paper discusses the use of partial reconfigurability in Xilinx FPGA designs in order to aid debugging. A debugging framework is proposed where the use of partial reconfigurability can allow for added flexibility by allowing a debugger to decide at run time what debugging module to use. This paper also presents an open source debugging tool which allows a user to read-out the contents of memory blocks in Xilinx designs without needing to use any JTAG adapter. This allows a user to debug an FPGA in situations which would otherwise be difficult, i.e. in the field.

  • 18.
    Engström, Adam
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Strömsparande arkitektur för inbyggnadslinux2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The objective of this work was to evaluate and implement a number of energy saving functions for a specific embedded system. The functions were then grouped into a number of energy levels with known properties in terms of functionality, energy consumption, and transition time between the levels.

    The embedded system consisted of an AT91 ARM9 processor, GSM/GPRS modem, display, Ethernet and other peripheral units. Some energy saving methods that were considered were suspend to RAM, suspend to disk, frequency scaling, and methods for saving energy in the modem, Ethernet, USB and display backlight. The functions were grouped into levels and an interface was specified for controlling the energy level.

    It proved possible to get known properties within the defined energy levels, even though the paritioning of functions into these levels proved to be sub-optimal in a typical application usage scenario because it was designed for mainly energy consumption, not usage.

    The final result is a number of energy saving functions grouped into levels, which are controllable via an application interface. Each of the levels have a known energy consumption in both loaded and un-loaded mode.

  • 19.
    Eriksson, Lars
    et al.
    Linköping University, Department of Electrical Engineering, Vehicular Systems. Linköping University, Faculty of Science & Engineering.
    Nezhadali, Vaheed
    Linköping University, Department of Electrical Engineering, Vehicular Systems. Linköping University, Faculty of Science & Engineering.
    Andersson, Conny
    Linköping University.
    Compressor Flow Extrapolation and Library Design for the Modelica Vehicle Propulsion Library - VehProLib2016In: SAE 2016 World Congress and Exhibition, SAE International , 2016, article id 2016-01-1037Conference paper (Refereed)
    Abstract [en]

    Modelbased systems engineering is becoming an important tool when meeting the challenges of developing the complex future vehicles that fulfill the customers and legislators ever increasing demands for reduced pollutants and fuel consumption. To be able to work systematically and efficiently it is desirable to have a library of components that can be adjusted and adapted to each new situation. Turbocharged engines are complex and the compressor model serves as an in-depth example of how a library can be designed, incorporating the basic physics and allowing fine tuning as more information becomes available. A major part of the paper is the summary and compilation of a set of rules of thumb for compressor map extrapolation. The considerations discussed are extrapolation to surge, extrapolation to restriction region, and extrapolation out to choking. Furthermore the compressor diameter is coupled to the maximum performance of the compressor such as maximum speed, mass flow, and pressure ratio. All this is a result of an analysis of a database of more than 300 compressors. The paper uses the compressor modeling to discuss how wishes for extendability and reuse of component performance influences the library design. A Modelica library named Vehicle Propulsion Library VehProLib has been developed to meet these goals by including basic components that give a starting point for modeling and at the same time allows reuse and extendablility.

  • 20.
    Faltpihl, Peter
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Ultrasonic sensing design and implementation for detecting and interacting with human beings in an AI system2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis covers the work performed to implement a Sonar sensor solution to detect human beings on a robotic lamp. A previously available solution was evaluated, but had to be redesigned due to faulty electronics. New hardware was developed, together with software to control this hardware. A software implementation of this new Sonar sensor system was also developed, on the robotic lamp itself.

    The nature of this thesis was very practical, so this report will focus on describing the different design stages that were performed, together with a wide discussion about future improvements and work, in order to achieve a robotic lamp that interacts with a human in an interesting manner.

  • 21.
    Fize, Florian
    Linköping University, Department of Computer and Information Science.
    From Theory to Implementation of Embedded Control Applications: A Case Study2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Control applications are used in almost all scientific domains and are subject to timing constraints. Moreover, different applications can run on the same platform which leads to even more complex timing behaviors. However, some of the timing issues are not always considered in the implementation of such applications, and this can make the system fail.

    In this thesis, the timing issues are considered, i.e., the problem of non-constant delay in the control of an inverted pendulum with a real-time kernel running on an ATmega328p micro-controller.

    The study shows that control performance is affected by this problem.

    In addition, the thesis, reports the adaptation of an existing real-time kernel based on an EDF (Earliest Deadline First) scheduling policy, to the architecture of the ATmega328p.

    Moreover, the new approach of a server-based kernel is implemented in this thesis, still on the same Atmel micro-controller.

  • 22.
    Fries, Jakob
    et al.
    Linköping University, Department of Electrical Engineering, Computer Engineering.
    Johansson, Simon
    Linköping University, Department of Electrical Engineering, Computer Engineering.
    A Modular 3D Graphics Accelerator for FPGA2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A modular and area-efficient 3D graphics accelerator for tile based rendering in FPGA systems has been designed and implemented. The accelerator supports a subset of OpenGL, with features such as mipmapping, multitexturing and blending. The accelerator consists of a software component for projection and clipping of triangles, as well as a hardware component for rasterization, coloring and video output. Trade-offs made between area, performance and functionality have been described and justified. In order to evaluate the functionality and performance of the accelerator, it has been tested with two different applications.

  • 23.
    Frisk, Erik
    et al.
    Linköping University, Department of Electrical Engineering, Vehicular Systems. Linköping University, Faculty of Science & Engineering.
    Krysander, Mattias
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, Faculty of Science & Engineering.
    Jung, Daniel
    Linköping University, Department of Electrical Engineering, Vehicular Systems. Linköping University, Faculty of Science & Engineering.
    A Toolbox for Analysis and Design of Model Based Diagnosis Systems for Large Scale Models2017In: IFAC PAPERSONLINE, ELSEVIER SCIENCE BV , 2017, Vol. 50, no 1, p. 3287-3293Conference paper (Refereed)
    Abstract [en]

    To facilitate the use of advanced fault diagnosis analysis and design techniques to industrial sized systems, there is a need for computer support. This paper describes a Matlab toolbox and evaluates the software on a challenging industrial problem, air-path diagnosis in an automotive engine. The toolbox includes tools for analysis and design of model based diagnosis systems for large-scale differential algebraic models. The software package supports a complete tool-chain from modeling a system to generating C-code for residual generators. Major design steps supported by the tool are modeling, fault diagnosability analysis, sensor selection, residual generator analysis, test selection, and code generation. Structural methods based on efficient graph theoretical algorithms are used in several steps. In the automotive diagnosis example, a diagnosis system is generated and evaluated using measurement data, both in fault-free operation and with faults injected in the control-loop. The results clearly show the benefit of the toolbox in a model-based design of a diagnosis system. Latest version of the toolbox can be downloaded at faultdiagnosistoolbox.github.io. (C) 2017, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.

  • 24.
    Fritzson, Peter
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Model-based development of sustainable cyber-physical systems including requirement formalization using the OpenModelica Model-based Development Toolkit2016In: ACM PROCCEDINGS OF THE 10TH EUROPEAN CONFERENCE ON SOFTWARE ARCHITECTURE WORKSHOPS (ECSA-W), ASSOC COMPUTING MACHINERY , 2016Conference paper (Refereed)
    Abstract [en]

    Large-scale and increasingly software-defined systems in power and factory automation are very long-lived. Longevity requires sustainability-economically, environmentally and last but not least in terms of usability. Sustainability therefore requires continuous change. In this talk we look at handling requirements, models, and implementations in a model-driven formal way that lends itself to a more systematic change tracking than traditional software development approaches and languages, but that also crosses boundaries of software-controlled physical equipment models (so-called cyber-physical systems), distributed digital control (networked systems) and software services. The industry is currently seeing a rapid development of cyber-physical system products. The systems that are developed have increasing demands of sustainability, dependability and usability. Moreover, lead time and cost efficiency continue to be essential for industry competitiveness. Extensive use of modeling and simulation - Model-Based Systems Engineering (MBSE) tools - throughout the value chain and system life-cycle is one of the most important ways to effectively target these challenges. Simultaneously there is an increased interest in open source tools that allow more control of tool features and support, and increased cooperation and shared access to knowledge and innovations between organizations. In this talk we briefly present technology and open source tooling for MBSE based on the Modelica and UML standards, supported by tools such as OpenModelica and Papyrus respectively. Modelica is a modern, strongly typed, declarative, equation-based, and object-oriented language for modeling and simulation of complex cyber-physical systems, whereas UML is a wide-spread industrial standard for software modeling. We present the OpenModelica open source MBSE environment including the ModelicaML Eclipse plug-in integrating Modelica and UML, covering the development process starting from business processes, via requirements, to models, which can be compiled to simulations or to product code. An important question is whether a particular system design fulfills or violates requirements that are imposed on the system under development. We give examples of case studies starting with natural-language requirements and show briefly how they are translated into models. Then, designs and verification scenarios are modeled, and simulation models are composed and simulated automatically. The simulation results produced can then be used to draw conclusions on requirement fulfillment. Other features of the environment are meta modeling for efficient model transformations, the Functional Mockup Interface for general tool integration, model-based optimization, as well as generation of parallel code for multi-core architectures.

  • 25.
    Garro, Alfredo
    et al.
    Department of Informatics, Modeling, Electronics and Systems Engineering (DIMES), University of Calabria, Italy.
    Tundis, Andrea
    Department of Informatics, Modeling, Electronics and Systems Engineering (DIMES), University of Calabria, Italy.
    Bouskela, Daniel
    R&D Division, Electricité de France (EDF), France.
    Jardin, Audrey
    R&D Division, Electricité de France (EDF), France.
    Nguyen, Thuy
    R&D Division, Electricité de France (EDF), France.
    Otter, Martin
    Institute of System Dynamics and Control, DLR German Aerospace Center, Germany.
    Buffoni, Lena
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Fritzson, Peter
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Sjölund, Martin
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Schamai, Wladimir
    Airbus Group Innovations, Hamburg, Germany.
    Olsson, Hans
    Dassault Systèmes AB, Sweden.
    On formal cyber physical system properties modeling: a new temporal logic language and a Modelica-based solution2016In: 2016 IEEE International Symposium on Systems Engineering (ISSE), IEEE , 2016, p. 112-119Conference paper (Refereed)
    Abstract [en]

    Modeling and Simulation methods, tools and techniques aim at supporting the different phases of the lifecycle of modern systems, going from requirements analysis to system design and operation. However, their effective application requires investigating several aspects such as the formal modeling of system requirements and the binding and automated composition between heterogeneous models (e.g. requirements models, architectural models, behavioral models). In this context, the paper presents a new formal requirement modeling language based on temporal logic, called FORM-L, and a software library, based on the Modelica language, that implements the constructs provided by FORM-L so as to enable the visual modeling of system properties as well as their verification through simulation. The effectiveness of the proposal is shown on a real case study concerning an Intermediate Cooling System.

  • 26.
    Gorm Larsen, Peter
    et al.
    Aarhus University, Denmark.
    Fitzgerald, John
    Newcastle University, England.
    Woodcock, Jim
    University of York, England.
    Fritzson, Peter
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Brauer, Joerg
    Verified Syst Int, Germany.
    Kleijn, Christian
    Controllab Prod, Netherlands.
    Lecomte, Thierry
    Clearsy SAS, France.
    Pfeil, Markus
    TWT Science and Innovat, Germany.
    Green, Ole
    Agro Intelligence, Denmark.
    Basagiannis, Stylianos
    United Technology Research Centre, Ireland.
    Sadovykh, Andrey
    Softeam, France.
    Integrated Tool Chain for Model-based Design of Cyber-Physical Systems: The INTO-CPS Project2016In: 2016 2ND INTERNATIONAL WORKSHOP ON MODELLING, ANALYSIS, AND CONTROL OF COMPLEX CPS (CPS DATA), IEEE , 2016Conference paper (Refereed)
    Abstract [en]

    We describe INTO-CPS, a project that aims to realise the goal of integrated tool chains for the collaborative and multidisciplinary engineering of dependable Cyber-Physical Systems (CPSs). Challenges facing model-based CPS engineering are described, focussing on the semantic diversity of models, management of the large space of models and artefacts produced in CPS engineering, and the need to evaluate effectiveness in industrial settings. We outline the approach taken to each of these issues, particularly on the use of semantically integrated multi-models, links to architectural modelling, code generation and testing, and evaluation via industry-led studies. We describe progress on the development of a prototype tool chain from baseline tools, and discuss ongoing challenges and open research questions in this area.

  • 27.
    Gratorp, Eric
    Linköping University, Department of Electrical Engineering, Computer Vision. Linköping University, The Institute of Technology.
    Evaluation of online hardware video stabilization on a moving platform2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Recording a video sequence with a camera during movement often produces blurred results. This is mainly due to motion blur which is caused by rapid movement of objects in the scene or the camera during recording. By correcting for changes in the orientation of the camera, caused by e.g. uneven terrain, it is possible to minimize the motion blur and thus, produce a stabilized video.

    In order to do this, data gathered from a gyroscope and the camera itself can be used to measure the orientation of the camera. The raw data needs to be processed, synchronized and filtered to produce a robust estimate of the orientation. This estimate can then be used as input to some automatic control system in order to correct for changes in the orientation

    This thesis focuses on examining the possibility of such a stabilization. The actual stabilization is left for future work. An evaluation of the hardware as well as the implemented methods are done with emphasis on speed, which is crucial in real time computing.

  • 28.
    Gunhardson, Erica
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Indoor Positioning Using Angle of Departure Information2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    I detta examensarbete undersöks möjligheten att kunna använda en positioneringsmetod som inte enbart förlitar sig på den uppmätta signalstyrkan. Istället används en metod som bestämmer från vilken vinkel en signal uppkommer ifrån. Den här tekniken kallas för direction-finding. När informationen om signalens vinkel fastställts används den i ett positioningsfilter som uppskattar positionen. Två tillvägagångssätt har använts i den här rapporten, ett där enbart vinkeln används och ett där både signalstyrka och vinkel används.

  • 29.
    Gustafsson, Robin
    et al.
    Linköping University, Department of Computer and Information Science.
    Blomqvist, Niklas
    Linköping University, Department of Computer and Information Science.
    Options handling using external devices in forklift trucks2016Independent thesis Basic level (university diploma), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    Unique customizations (options) of features in forklifts are often requested by customers. When new options are created or existing options have to be modified in the main software the complexity increases, the firmware revision pool gets large and with the increasing code size the memory limit is threatened.

    This affects the software development since the frequent modification of the option handler software is very resource consuming. Therefore it is desirable to have a highly modular system for the option handler to simplify the development process. Although the market value of this improvement is negligible the possible long term savings is the desirable effect.

    This thesis explores the possibility of migrating the option handling software to a dedicated hardware module. This helps the development process by increasing the modularity of the system architecture and thus reducing the development scope. The tools and the approach to accomplish this option handler is analyzed. A system model of the resulting approach is designed and a prototype is developed to validate the result.

  • 30.
    Högberg, Marcus
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    A Cross-platform Picture Transfer Protocol for Linux-based Camera2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Universal Serial Bus, USB, is widely used for connecting peripheral devices to a computer. Through the years devices that use USB has evolved and more and more complicated communication protocols have been developed using the USB standard. There are many different ways to set up communication between a USB device and a host computer. The USB standard does not include any security and this poses risks when designing communication over such a connection.

    This thesis investigates how a USB-based picture transfer protocol can be designed between a small camera running embedded Linux and a host computer. The USB functionality in Windows and Mac OS/X operating systems are investigated. Solutions to create a secure USB communication are also investigated. One of three the methods of creating a USB connection with a USB device running embedded Linux are chosen based on the investigations. A protocol is then designed and an implementation developed. The protocol designed in the thesis uses existing USB functionality in the host computer operating systems Windows and Mac OS/X.

    The designed protocol is evaluated for performance and security. The evaluation is made on an evaluation platform for the camera. The transfer speed of the protocol is measured to around 18 MB/s in an ideal environment. The designed protocol could be improved by using one of the security methods found in the investigations.

  • 31.
    Johansson, Cristina
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, Faculty of Science & Engineering.
    Multiobjective Optimization for Safety and Reliability Trade-off: Applications on Early Phases of Aircraft Systems Design2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    A strategic issue for any industrial company is to conceive safe and reliable systems while performing all systems’ intended functions at a minimum cost. System safety and reliability are fundamental to system design and involve a quantitative assessment prior to system development. Aircraft design is a multifaceted process that involves several different disciplines, system safety and reliability among them, to obtain o holistic approach of a complex product. During the last decades, the idea of trade-off between safety or reliability goals against other characteristics has become more prominent. Furthermore, while predictions of system performance can be made in early design phases with credible precision, within reasonable tolerances, reliability and system safety are seldom predicted with high accuracy and confidence. Making the right design decisions in the early design phase is vital to the success of a project. Nowadays, it is essential within the design of new products, to increase awareness (knowledge) early in the design phases and keep the design decisions (freedom) open as long as possible, and with that also keep down the allocated costs.

    This thesis presents MOSART (Multiobjective Optimization for Safety and Reliability Trade-off), a method promoting a systematic approach regarding trade-offs between system safety and reliability goals against other contradictory targets, such as weight and cost, in early design phases.

    A theoretical framework and context are presented in the first part of the thesis, including system safety and reliability methods and optimization techniques. The second and third parts are dedicated to contributions and papers, where seven papers are included. These papers approach different aspects of MOSART, from the basic idea to the implementation and usage of the method in the conceptual phase of aircraft systems design. Several aspects regarding the choice of system safety and reliability methods in early design phases are also included in the papers, e.g. evaluation of applicability of reliability methods in early design phases, considerations around the usage of these methods within the MOSART framework and a proposal of a guideline for how to choose the right reliability method. All the examples used in the papers are chosen from basic aircraft sub-systems.

    List of papers
    1. On the Usage of Reliability Methods in Early Design Phases
    Open this publication in new window or tab >>On the Usage of Reliability Methods in Early Design Phases
    2012 (English)In: 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, Published 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.

    Place, publisher, year, edition, pages
    Curran Associates, Inc., 2012
    Keywords
    System Reliability, Markov Analysis, Reliability Block Diagram, Fault Tree
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-94350 (URN)978-1-62276-436-5 (ISBN)
    Conference
    11th International Probabilistic Safety Assessment and Management Conference and the Annual European Safety and Reliability Conference 2012 (PSAM11 ESREL 2012), 25-29 June, Helsinki, Finland
    Available from: 2013-06-25 Created: 2013-06-25 Last updated: 2017-02-20Bibliographically approved
    2. Choosing the reliability approach: A guideline for selecting the appropriate reliability method in the design process
    Open this publication in new window or tab >>Choosing the reliability approach: A guideline for selecting the appropriate reliability method in the design process
    2013 (English)In: 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, Published 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.

    Place, publisher, year, edition, pages
    Loughborough: Loughborough University, UK, 2013
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-94352 (URN)9781907382611 (ISBN)
    Conference
    The 20th Advances in Risk and Reliability Technology Symposium, 21st – 23rd May 2013, Burleigh Court Conference Centre, Loughborough, Leicestershire, UK
    Available from: 2013-06-25 Created: 2013-06-25 Last updated: 2017-02-20Bibliographically approved
    3. Cost optimization with focus on reliability and system safety
    Open this publication in new window or tab >>Cost optimization with focus on reliability and system safety
    2013 (English)In: 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, Published 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.

    Place, publisher, year, edition, pages
    CRC Press, 2013
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-94353 (URN)10.1201/b15938-413 (DOI)9781138001237 (ISBN)9781315815596 (ISBN)
    Conference
    ESREL2013, 29 Sep-02 October, Amsterdam, Holland
    Available from: 2013-06-25 Created: 2013-06-25 Last updated: 2017-02-20Bibliographically approved
    4. An Industrial Implementation of an Optimization Based Method for Balancing Safety, Reliability and Weight of Aircraft Systems
    Open this publication in new window or tab >>An Industrial Implementation of an Optimization Based Method for Balancing Safety, Reliability and Weight of Aircraft Systems
    Show others...
    2017 (English)In: Risk, Reliability and Safety: Innovating Theory and Practice: Proceedings of ESREL 2016 (Glasgow, Scotland, 25-29 September 2016) / [ed] Lesley Walls, Matthew Revie and Tim Bedford, CRC Press, 2017, p. 1707-1713Conference paper, Published paper (Refereed)
    Abstract [en]

    The aim of this paper is to show how a method able of trade-offs such as system safety, reliability, weight and cost can be practically implemented in industry (SAAB Aeronautics). The scope is to facilitate the decision-making on the optimal design in early design phases. The method consists of several steps guiding the user to model each objective, verify and validate the models, perform optimization and finally visualize and select the results. Within the practical implementation of this method, several challenges are addressed and solved. For example, one challenge is to implement the trade-off method using the existing programs. Another challenge is the user friendliness of the implementation. In order to solve these challenges, the analysis is started and performed in Matlab. A Graphical User Interface guides the user to select the analysis to perform, budgets/requirements for each objective and parameters with influence on end-result. Data regarding the safety and reliability objectives, exported from Reliability Workbench program to Excel, is imported to Matlab, where the analysis is performed. The results are extracted into an Excel file, where the user can work further on visualization and selection. Two small examples are used to demonstrate this practical implementation of the trade-off method. Lessons learned are presented, strengths, limitations and development potential.

    Place, publisher, year, edition, pages
    CRC Press, 2017
    National Category
    Computer Systems Embedded Systems Software Engineering
    Identifiers
    urn:nbn:se:liu:diva-134590 (URN)000414164700242 ()9781138029972 (ISBN)9781315374987 (ISBN)
    Conference
    ESREL 2016, Glasgow, Scotland, 25-29 September 2016
    Note

    Funding agencies:The implementation presented in this paper is part of a research funded by Saab Aeronautics and the National Aviation Engineering Research Program (NFFP), jointly driven by the Swedish Armed Forces, the Swedish Defense Materiel Administration (FMV), and the Swedish Governmental Agency for Innovation Systems (VINNOVA).

    Available from: 2017-02-20 Created: 2017-02-20 Last updated: 2018-01-13Bibliographically approved
    5. How to use an Optimization-based Method Capable of Balancing Safety, Reliability, and Weight in an Aircraft Design Process
    Open this publication in new window or tab >>How to use an Optimization-based Method Capable of Balancing Safety, Reliability, and Weight in an Aircraft Design Process
    2017 (English)In: Nuclear engineering and technology : an international journal of the Korean Nuclear Society, ISSN 1738-5733, E-ISSN 2234-358X, Vol. 49, p. 404-410Article in journal (Refereed) Published
    Abstract [en]

    In order to help decision-makers in the early design phase to improve and make more cost-efficient system safety and reliability baselines of aircraft design concepts, a method (Multi-objective Optimization for Safety and Reliability Trade-off) that is able to handle trade-offs such as system safety, system reliability, and other characteristics, for instance weight and cost, is used. Multi-objective Optimization for Safety and Reliability Trade-off has been developed and implemented at SAAB Aeronautics. The aim of this paper is to demonstrate how the implemented method might work to aid the selection of optimal design alternatives. The method is a three-step method: step 1 involves the modelling of each considered target, step 2 is optimization, and step 3 is the visualization and selection of results (results processing). The analysis is performed within Architecture Design and Preliminary Design steps, according to the company’s Product Development Process. The lessons learned regarding the use of the implemented trade-off method in the three cases are presented. The results are a handful of solutions, a basis to aid in the selection of a design alternative. While the implementation of the trade-off method is performed for companies, there is nothing to prevent adapting this method, with minimal modifications, for use in other industrial applications.

    Place, publisher, year, edition, pages
    Elsevier, 2017
    Keywords
    Aircraft Design, Early Design Phases, MOSART, Safety, Reliability, Trade-off
    National Category
    Production Engineering, Human Work Science and Ergonomics Embedded Systems Computer Sciences Computer Systems Reliability and Maintenance
    Identifiers
    urn:nbn:se:liu:diva-134591 (URN)10.1016/j.net.2017.01.006 (DOI)000401102000015 ()
    Note

    Funding agencies: MOSART - Saab Aeronautics and the National Aviation Engineering Research Program [NFFP6 2013-01223]; Swedish Armed Forces; Swedish Defense Materiel Administration; Swedish Governmental Agency for Innovation Systems

    Available from: 2017-02-20 Created: 2017-02-20 Last updated: 2018-01-13Bibliographically approved
  • 32.
    Johansson, Cristina
    et al.
    Mendeley, Br€oderna Ugglasgatan, SE-582 54 Linköping, Sweden.
    Derelöv, Micael
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, Faculty of Science & Engineering.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, Faculty of Science & Engineering.
    How to use an Optimization-based Method Capable of Balancing Safety, Reliability, and Weight in an Aircraft Design Process2017In: Nuclear engineering and technology : an international journal of the Korean Nuclear Society, ISSN 1738-5733, E-ISSN 2234-358X, Vol. 49, p. 404-410Article in journal (Refereed)
    Abstract [en]

    In order to help decision-makers in the early design phase to improve and make more cost-efficient system safety and reliability baselines of aircraft design concepts, a method (Multi-objective Optimization for Safety and Reliability Trade-off) that is able to handle trade-offs such as system safety, system reliability, and other characteristics, for instance weight and cost, is used. Multi-objective Optimization for Safety and Reliability Trade-off has been developed and implemented at SAAB Aeronautics. The aim of this paper is to demonstrate how the implemented method might work to aid the selection of optimal design alternatives. The method is a three-step method: step 1 involves the modelling of each considered target, step 2 is optimization, and step 3 is the visualization and selection of results (results processing). The analysis is performed within Architecture Design and Preliminary Design steps, according to the company’s Product Development Process. The lessons learned regarding the use of the implemented trade-off method in the three cases are presented. The results are a handful of solutions, a basis to aid in the selection of a design alternative. While the implementation of the trade-off method is performed for companies, there is nothing to prevent adapting this method, with minimal modifications, for use in other industrial applications.

  • 33.
    Johansson, Cristina
    et al.
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, Faculty of Science & Engineering.
    Derelöv, Micael
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, Faculty of Science & Engineering.
    Ölvander, Johan
    Linköping University, Department of Management and Engineering, Machine Design. Linköping University, Faculty of Science & Engineering.
    Bergström, B.
    SAAB Aeronautics, Linköping, Sweden.
    Nilsson-Sundén, H.
    SAAB Aeronautics, Linköping, Sweden.
    An Industrial Implementation of an Optimization Based Method for Balancing Safety, Reliability and Weight of Aircraft Systems2017In: Risk, Reliability and Safety: Innovating Theory and Practice: Proceedings of ESREL 2016 (Glasgow, Scotland, 25-29 September 2016) / [ed] Lesley Walls, Matthew Revie and Tim Bedford, CRC Press, 2017, p. 1707-1713Conference paper (Refereed)
    Abstract [en]

    The aim of this paper is to show how a method able of trade-offs such as system safety, reliability, weight and cost can be practically implemented in industry (SAAB Aeronautics). The scope is to facilitate the decision-making on the optimal design in early design phases. The method consists of several steps guiding the user to model each objective, verify and validate the models, perform optimization and finally visualize and select the results. Within the practical implementation of this method, several challenges are addressed and solved. For example, one challenge is to implement the trade-off method using the existing programs. Another challenge is the user friendliness of the implementation. In order to solve these challenges, the analysis is started and performed in Matlab. A Graphical User Interface guides the user to select the analysis to perform, budgets/requirements for each objective and parameters with influence on end-result. Data regarding the safety and reliability objectives, exported from Reliability Workbench program to Excel, is imported to Matlab, where the analysis is performed. The results are extracted into an Excel file, where the user can work further on visualization and selection. Two small examples are used to demonstrate this practical implementation of the trade-off method. Lessons learned are presented, strengths, limitations and development potential.

  • 34.
    Johansson, Henrik
    Linköping University, Department of Electrical Engineering, Vehicular Systems. Linköping University, The Institute of Technology.
    Evaluation of Communication Interfaces for ElectronicControl Units in Heavy-duty Vehicles2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The number of electronic control units in heavy-duty vehicles has grown dramatically overthe last few decades. This has led to the use of communication buses to reduce the complexityand weight of the networks. There are reasons to believe that the de facto standardcommunication interface in the automotive industry, the Controller Area Network, is obsoletein some areas. Hence an evaluation of available communication interfaces is needed.This study focuses on lower levels of the Open Systems Interconnect (osi) model. Initially atheoretical study is presented in order to give an overview of automotive embedded systemsin general and different communication interfaces in particular. Ethernet and FlexRay areidentified as two interfaces of interest for future use in Scanias vehicles. The former is new inautomotive applications but is believed to become popular over the years to come. A possibleuse of this interface could be as a backbone to take the load off other interfaces. The use ofFlexRay in Scanias vehicles is limited because of the modular system used and the staticscheduling needed. It could however be used between mandatory ecus where the nodes andthe messages are all known beforehand.The report also contains the result from emission measurements on a number of interfacesperformed using a stripline antenna in a shielded enclosure. Strong conclusions can not bedrawn since it’s hard to tell what the transceivers, circuit boards and interfaces contributedto in the spectra with the method used. The FlexRay hardware is worse than for the otherinterfaces. Similarities can be seen between low-speed and high-speed can but it could becharacteristics of the transceivers used rather than the interface itself.

  • 35.
    Kamula, Juha
    et al.
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, The Institute of Technology.
    Hansson, Rikard
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, The Institute of Technology.
    Rugged Portable Communication System2013Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Todays modern warfare puts high demands on military equipment. Where soldiers are concerned, types of communication equipment such as radios, displays and headsets play a central role. A modern soldier is often required to maintain communication links with other military units. These units can, for example, consist of platoon commanders, headquarters and other soldiers. If the soldier needs to make a report to several units, the message needs to be sent to several radio networks that are connected to these separate units. This multiplicity in turn requires several items of radio equipment connected to the radio network frequencies. Considering all the communication equipment that is used by a modern soldier, the parallel data flow and all the weight a soldier needs to carry, can get quite extensive. 

    \noindentAt Saab AB it has been proven that a combination of powerful embedded hardware platforms and cross platform software fulfills the communication needs. However, the weight issue still remains as these embedded platforms are quite bulky and hard to carry. In order to increase the portability, a tailored Android application for smaller low-power embedded hardware platform has been developed at Saab AB. Saab AB has also developed a portable analogue interconnection unit for connecting three radios and a headset, the SKE (Sammankopplingsenhet).

    \noindentSaab AB intends to develop a new product for soldiers, the RPCS (Rugged Portable Communication System), with capacities of running the Android application and combining the audio processing functionality of the SKE. This thesis focuses on developing a hardware platform prototype for the RPCS using Beagleboard. The SKE audio processing functionality is developed as a software application running on the Beagleboard.

  • 36.
    Karlsson, Sara
    Linköping University, Department of Electrical Engineering, Electronics System. Linköping University, The Institute of Technology.
    Micro NPU for Baseband Interconnect2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The aim of this work is to investigate the possibility to implement a configurable NPU (Network Processing Unit) in the next generation of Ericsson’s EMCAs (Ericsson Multi Core Architecture). The NPU is constructed so that it can be configured for either Ethernet or xIO-s, as either a transmitter or a receiver. The motive for doing the work is that many protocols have similar functions and there could be possible advantages to have a configurable protocol choice in future hardware.

    A model of a NPU will be created in SystemC using the TLM 2.0 interface. The model will be analyzed to evaluate its complexity regarding a possible modification to also make it configurable for CPRI.

    The result that is presented is that it would be possible to implement a configurable NPU in the future EMCAs. The result is based on the conclusion that the protocols use many similar functions and most of the blocks could be made configurable for use with different protocols. Configurable blocks would benefit a configurable NPU as it would require fewer resources than separate blocks for each protocol.

  • 37.
    Keskisärkkä, Robin
    et al.
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Science & Engineering.
    Blomqvist, Eva
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Science & Engineering.
    Supporting Real-Time Monitoring in Criminal Investigations2015In: SEMANTIC WEB: ESWC 2015 SATELLITE EVENTS, SPRINGER INT PUBLISHING AG , 2015, Vol. 9341, p. 82-86Conference paper (Refereed)
    Abstract [en]

    Being able to analyze information collected from streams of data, generated by different types of sensors, is becoming increasingly important in many domains. This paper presents an approach for creating a decoupled semantically enabled event processing system, which leverages existing Semantic Web technologies. By implementing the actor model, we show how we can create flexible and robust event processing systems, which can leverage different technologies in the same general workflow. We argue that in this context RSP systems can be viewed as generic systems for creating semantically enabled event processing agents. In the demonstration scenario we show how real-time monitoring can be used to support criminal intelligence analysis, and describe how the actor model can be leveraged further to support scalability.

  • 38.
    Kim, Jin-Hyun
    et al.
    INRIA/IRISA, France.
    Legay, Axel
    INRIA/IRISA, France.
    Traonouez, Louis-Marie
    INRIA/IRISA, France.
    Boudjadar, Abdeldjalil
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Nyman, Ulrik
    Aalborg University, Denmark.
    Larsen, Kim G.
    Aalborg University, Denmark.
    Lee, Insup
    University of Pennsylvania.
    Choi, Jin-Young
    Korea University, S. Korea.
    Optimizing the Resource Requirements of Hierarchical Scheduling Systems2016In: SIGBED Review, ISSN 1551-3688, Vol. 13, no 3, p. 41-48Article in journal (Other academic)
    Abstract [en]

    Compositional reasoning on hierarchical scheduling systems is a well-founded formal method that can construct schedulable and optimal system configurations in a compositional way. However, a compositional framework formulates the resource requirement of a component, called an interface, by assuming that a resource is always supplied by the parent components in the most pessimistic way. For this reason, the component interface demands more resources than the amount of resources that are really sufficient to satisfy sub-components. We provide two new supply bound functions which provides tighter bounds on the resource requirements of individual components. The tighter bounds are calculated by using more information about the scheduling system.

    We evaluate our new tighter bounds by using a model-based schedulability framework for hierarchical scheduling systems realized as Uppaal models. The timed models are checked using model checking tools Uppaal and Uppaal SMC, and we compare our results with the state of the art tool CARTS.

  • 39.
    Kini, Anup
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Hardware implementation of a Partial Dynamic Reconfiguration Controller2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Partial Dynamic Reconfiguration (PDR) of Field Programmable Gate Arrays (FPGAs) wasintroduced to overcome the need for more resources on the FPGA fabric. This enabled parts of thedevice to be reconfigured at runtime, while the rest of the system continued to function without anyinterruptions. Therefore, PDR could change the functionality and efficiency of the system in order toaccommodate more hardware modules, save power and fabric area. Typically, PDR involves the designof modules that are independent of each other so that they can be loaded on the same fabric area(reconfigurable region) one after the other.

    This thesis will introduce a framework that enables designers to use PDR in their applications,without having to go into the details of the reconfiguration process. It provides an elegant interface,based on standalone IP modules and an API, which can be used to load modules on to the FPGA fabricat runtime with very little overhead to the main processor. The framework will copy the partial bitfiles from the configuration memory and reconfigure the FPGA while the application continues toexecute useful computations. It will notify the application with an interrupt after completion of thereconfiguration process so that the application can switch context between hardware and softwaremodules.

    We validate our controller by using simple test cases that perform FPGA configurationprefetching. However, the framework presented in this thesis can be used as a foundation for manysystem optimizations targeted at dynamically reconfigurable platforms.

  • 40.
    Kleback, Oskar
    Linköping University, Department of Electrical Engineering, Computer Engineering.
    Study on Low Voltage Power Electronics Used for Actuator Control2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The aim of this thesis is to understand the current implementation, how different hardware and output frequency affects the hydraulic actuators in the current platform and Then an improve the controller should be presented. This needs to be both faster then the current controller and should not use more CPU recurses then necessary. With the understanding of current controller, three new regulators where implemented and tested. One uses a PI regulator and the other two uses an adaptive algorithm to generate the control signal. All where faster than the current one and the PI-implementation uses the lowest amount of CPU recurses, on the other hand this needs to be calibrated for the different hardware and output frequency’s. ThetwoadaptivecontrollersrequiresahigheramountofCPUrecurses, instead it requires less calibration to work.

  • 41.
    Källström, Petter
    et al.
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, Faculty of Science & Engineering.
    Gustafsson, Oscar
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, Faculty of Science & Engineering.
    Fast and Area Efficient Adder for Wide Data in Recent Xilinx FPGAs2016In: 26th International Conference on Field-Programmable Logic and Applications, Lausanne: IEEE , 2016, p. 338-341Conference paper (Refereed)
    Abstract [en]

    Most modern FPGAs have very optimised carry logic for efficient implementations of ripple carry adders (RCA). Some FPGAs also have a six input look up table (LUT) per cell, whereof two inputs are used during normal addition. In this paper we present an architecture that compresses the carry chain length to N/2 in recent Xilinx FPGA, by utilising the LUTs better. This carry compression was implemented by letting some cells calculate the carry chain in two bits per cell, while some others calculate the summary output bits. In total the proposed design uses no more hardware than the normal adder. The result shows that the proposed adder is faster than a normal adder for word length larger than 64 bits in Virtex-6 FPGAs.

  • 42.
    Lantz, Fredrik
    et al.
    Linköping University, Department of Electrical Engineering, Integrated Circuits and Systems.
    Johansson, Pontus
    Linköping University, Department of Electrical Engineering, Integrated Circuits and Systems.
    Using Harvested Energy to Power a Wireless System and Measure Vibrations2016Independent thesis Basic level (university diploma), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    The work described in this paper aims to test whether or not it is possible to power a system on energy harvested from vibrations and use that energy to measure how much it vibrates. The goal has been to produce a prototype system that uses that technique to discover damages on drones in an early stage. The reader will get to experience everything from design to testing of the system. The reader will also get an insight in which problems occurred during the project, how they have been handled and which conclusions have been made.The system could be applied in a variety of different situations to detect damages and which could prevent the damages from leading to severe problems.

  • 43.
    Lehtojärvi, Jonas
    Linköping University, Department of Electrical Engineering, Electronics System. Linköping University, The Institute of Technology.
    En lågeffektsmodul för markfuktsmätning med fokus på ZigBee2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna rapport presenterar ett examensarbete som gått ut på att bygga en prototyp av ett trådlöst sensornätverk vars funktion är att mäta fuktighet och lagra värdena på ett minneskort. Detta utförs för att man förhoppningsvis kan bli varnad för en eventuellt inkommande torka. Prototypen som utvecklats består av en huvudenhet och en sensorenhet. Det är möjligt att koppla upp flera sensorenheter till detta system och slutligen kommer det vara flertalet sensorenheter uppkopplade mot varje huvudenhet. Kommunikationssättet som används för kontakt med omvärlden är Bluetooth och det förutsätter att en person har möjligheten att åka till alla stationer och samla upp den data som lagrats. För utvecklandet av prototypen har ett kopplingsdäck och ett STK-500 använts vilket har begränsat val av mikrokontroller till en mikrokontroller från Atmel. Den mikrokontroller som används är en ATMega328. Kommunikationen mellan enheterna sker via ZigBee. Detta trådlösa sensornätverk gör en mätning av markfukt en gång om dagen och lagrar mätvärden på ett minneskort. När man via det grafiska gränssnittet på  datorn väljer att ladda ner mätvärdena skrivs de in i en fil på datorn och raderas från det minneskort som sitter i huvudenheten. Prototypen kommer utvecklas och om slutliga resultatet visar sig fungera som förväntat även installeras i flodområdet Limpopo i nordliga Sydafrika som projektet inriktar sig mot.

  • 44.
    Leitão, Paulo
    et al.
    Polytechnic Institute of Bragança, Campus Sta Apolónia, Apartado 1134, 5301-857 Bragança, Portugal .
    Ribeiro, Luis
    Linköping University, Department of Management and Engineering, Manufacturing Engineering. Linköping University, Faculty of Science & Engineering.
    Barata, José
    New University of Lisbon, Faculties of Science and Technology, Caparica, Portugal.
    Vogel-Heuser, Birgit
    Technische Universität München, Germany.
    Summer school on intelligent agents in automation: Hands-on educational experience on deploying industrial agents2016In: IECON 2016 - 42nd Annual Conference of the IEEE Industrial Electronics Society, Institute of Electrical and Electronics Engineers (IEEE), 2016, p. 6602-6607Conference paper (Refereed)
    Abstract [en]

    Cyber-physical systems constitutes a framework to develop intelligent, distributed, resilient, collaborative and cooperative systems, promoting the fusion of computational entities and physical devices. Agent technology plays a crucial role to develop this kind of systems by offering a decentralized, distributed, modular, robust and reconfigurable control structure. This paper describes the implementation of a summer school aiming to enhance the participants’ knowledge in the field of multi-agent systems applied to industrial environments, being able to gain the necessary theoretical and practical skills to develop real industrial agent based applications. This is accomplished in an international framework where individual knowledge and experiences are shared in a complementary level.

  • 45.
    Lima, José
    et al.
    Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa 2 Intituto de Engenharia e Geociências, Universidade Federal do Oeste do Pará, Brasil.
    Lima, Celson
    Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa 2 Intituto de Engenharia e Geociências, Universidade Federal do Oeste do Pará, Brasil.
    Gomes, Vasco
    Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa 2 Intituto de Engenharia e Geociências, Universidade Federal do Oeste do Pará, Brasil.
    Martins, João F
    Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa 2 Intituto de Engenharia e Geociências, Universidade Federal do Oeste do Pará, Brasil.
    Barata, José
    Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa 2 Intituto de Engenharia e Geociências, Universidade Federal do Oeste do Pará, Brasil.
    Ribeiro, Luis
    Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa 2 Intituto de Engenharia e Geociências, Universidade Federal do Oeste do Pará, Brasil.
    Cândido, Gonçalo
    Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa 2 Intituto de Engenharia e Geociências, Universidade Federal do Oeste do Pará, Brasil.
    Dpws as specific communication service mapping for iec 618502011In: 9th IEEE International Conference on Industrial Informatics (INDIN), 2011, IEEE , 2011, p. 193-198Conference paper (Refereed)
    Abstract [en]

    The present article describes the development of a standard-based software infrastructure, supported by the Service Oriented Architecture paradigm, for the management of complex distributed energy systems where efficient energy production, distribution and consumption are considered. The work has been developed on the context of the NEMO&CODED project (NEMO) and focuses on NEMO's architectural aim to enable seamless device integration, with plug and play features and vendor independent concepts, using the IEC 61850 ACSI model and services and adopting DPWS as Specific Communication Service Mapping.

  • 46.
    Liss, Jonathan
    Linköping University, Department of Electrical Engineering, Electronics System. Linköping University, The Institute of Technology.
    Implementation of a VBR MPEG-stream receiver in an FPGA2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Nowdays, the transmission of digital TV-signals tends to move towards more untraditional medias, such as TCP/IP networks.

    This thesis focused on the problems involved in receiving MPEG transport streams of variable bitrate from a TCP/IP connection, such as jitter and clock synchronization. A suggestion for recovering the transport stream is presented along with a implementation for an Xilinx FPGA targeted for a head end device. The implementation was written in a mix of VHDL and Verilog.

  • 47.
    Liu, Yang
    et al.
    Faculty of Technology, University of Vaasa, Vaasa, Finland.
    Jantti, Riku
    Faculty of Technology, University of Vaasa, Vaasa, Finland.
    A Study Towards Enhanced Reliability Performance of Remote Control and Monitoring Application Over Commercial Wireless Communication Networks2006In: 2006 International Conference on Wireless Communications, Networking and Mobile Computing, Institute of Electrical and Electronics Engineers (IEEE), 2006, p. 1-4Conference paper (Refereed)
    Abstract [en]

    Remote control and monitoring systems provide many useful operating advantages in industrial automation and demand highly reliable and secure communication means. Their widespread use is, however, limited because of the high cost of current communications in use making them economically infeasible. Hence, there is a need to develop new low cost communication and control concepts by making such solutions economically feasible. In this paper, we present a scheme for implementing reliable wireless communication links for application of remote control and monitoring system based on current available commercial wireless communication networks, e.g. GPRS/EDGE/UMTS. The reliability enhancement over wireless networks has been proposed and its performance has been studied. This paper examines the proposed solution by means of both analytical and numerical evaluation, and has shown that the demanded reliability performance can be met by using only commercial wireless communication networks.

  • 48.
    Liu, Yang
    et al.
    Department of Information Technology, Vaasa University of Applied Sciences, Vaasa, Finland / School of Electrical and Electronic Engineering, Hubei University of Technology, Wuhan, China.
    Vo, Thanh Vinh
    Department of Information Technology, Vaasa University of Applied Sciences, Vaasa, Finland.
    A Fast Machine Vision for Automated Packaging2012In: Electrical, Information Engineering and Mechatronics 2011: Proceedings of the 2011 International Conference on Electrical, Information Engineering and Mechatronics (EIEM 2011) / [ed] Wang, Xudong; Wang, Fuzhong; Zhong, Shaobo, Springer, 2012, p. 719-726Chapter in book (Other academic)
    Abstract [en]

    This paper introduces a fast, simple, cheap but accurate and reliable vision system designed for the automated packaging robot application, which is to replace manual product packaging. The objective is to develop a vision system and algorithm for such application and achieve pattern tracking in nearly real-time with a normal entry-level computer. This paper describes in detail the implementation of the proposed vision system including image processing and pattern recognition. The application uses only a simple gray scale image of product as sample pattern to track the product in the scene at real-time speed, which has come near to replace human eyes. The proposed machine vision has been implemented and equipped on a real ABB robot arm with other related hardware/software to achieve automated packaging. The performance has been evaluated as a success in both timing and precision. Its stability and reliability are also proved under laboratory testing environment.

  • 49.
    Lofwenmark, Andreas
    et al.
    Saab Aeronaut, Linkoping, Sweden.
    Nadjm-Tehrani, Simin
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Fault and timing analysis in critical multi-core systems: A survey with an avionics perspective2018In: Journal of systems architecture, ISSN 1383-7621, E-ISSN 1873-6165, Vol. 87, p. 1-11Article, review/survey (Refereed)
    Abstract [en]

    With more functionality added to future safety-critical avionics systems, new platforms are required to offer the computational capacity needed. Multi-core processors offer a potential that is promising, but they also suffer from two issues that are only recently being addressed in the safety-critical contexts: lack of methods for assuring timing determinism, and higher sensitivity to permanent and transient faults due to shrinking transistor sizes. This paper reviews major contributions that assess the impact of fault tolerance on worst-case execution time of processes running on a multi-core platform. We consider the classic approach for analyzing the impact of faults in such systems, namely fault injection. The review therefore explores the area in which timing effects are studied when fault injection methods are used. We conclude that there are few works that address the intricate timing effects that appear when inter-core interferences due to simultaneous accesses of shared resources are combined with fault tolerance techniques. We assess the applicability of the methods to currently available multi-core processors used in avionics. Dark spots on the research map of the integration problem of hardware reliability and timing predictability for multi-core avionics systems are identified.

  • 50.
    Lundahl, Kristoffer
    et al.
    Linköping University, Department of Electrical Engineering. Linköping University, The Institute of Technology.
    Åslund, Jan
    Linköping University, Department of Electrical Engineering, Vehicular Systems. Linköping University, The Institute of Technology.
    Nielsen, Lars
    Linköping University, Department of Electrical Engineering. Linköping University, The Institute of Technology.
    Investigating Vehicle Model Detail for Close to Limit Maneuvers Aiming at Optimal Control2011Conference paper (Other academic)
    Abstract [en]

    In advanced road vehicle safety systems it is imperative to have a model describing the vehicle motions and behaviors with sufficient precision. Often a model incorporating a higher level of complexity generates more accurate data, with the disadvantage of demanding additional calculation power. This study will therefore focus on investigating how models of different detail level represents the vehicle behavior, for maneuvers going from moderate to more aggressive. The characteristics in particular investigated are tire saturation, tire force lag and the effect of load transfers. A vehicle testbed has also been developed, making model validations towards experimental data available.

12 1 - 50 of 94
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