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  • 51.
    Leitão, Paulo
    et al.
    Polytechnic Institute of Bragança, Campus Sta Apolónia, Apartado 1134, 5301-857 Bragança, Portugal .
    Ribeiro, Luis
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell Produktion. Linköpings universitet, Tekniska fakulteten.
    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 agents2016Inngår i: IECON 2016 - 42nd Annual Conference of the IEEE Industrial Electronics Society, Institute of Electrical and Electronics Engineers (IEEE), 2016, s. 6602-6607Konferansepaper (Fagfellevurdert)
    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.

  • 52.
    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 618502011Inngår i: 9th IEEE International Conference on Industrial Informatics (INDIN), 2011, IEEE , 2011, s. 193-198Konferansepaper (Fagfellevurdert)
    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.

  • 53.
    Liss, Jonathan
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Implementation of a VBR MPEG-stream receiver in an FPGA2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    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.

  • 54.
    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 Networks2006Inngår i: 2006 International Conference on Wireless Communications, Networking and Mobile Computing, Institute of Electrical and Electronics Engineers (IEEE), 2006, s. 1-4Konferansepaper (Fagfellevurdert)
    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.

  • 55.
    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 Packaging2012Inngår i: 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, s. 719-726Kapittel i bok, del av antologi (Annet vitenskapelig)
    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.

  • 56.
    Ljungqvist, Oskar
    Linköpings universitet, Institutionen för systemteknik, Reglerteknik. Linköpings universitet, Tekniska fakulteten.
    On motion planning and control for truck and trailer systems2019Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    During the last decades, improved sensor and hardware technologies as well as new methods and algorithms have made self-driving vehicles a realistic possibility in the near future. Thanks to this technology enhancement, many leading automotive and technology companies have turned their attention towards developing advanced driver assistance systems (ADAS) and self-driving vehicles. Autonomous vehicles are expected to have their first big impact in closed areas, such as mines, harbors and loading/offloading sites. In such areas, the legal requirements are less restrictive and the surrounding environment is more controlled and predictable compared to urban areas. Expected positive outcomes include increased productivity and safety, reduced emissions and the possibility to relieve the human from performing complex or dangerous tasks. Within these sites, different truck and trailer systems are used to transport materials. These systems are composed of several interconnected modules, and are thus large and highly unstable while reversing. This thesis addresses the problem of designing efficient motion planning and feedback control frameworks for such systems.

    First, a cascade controller for a reversing truck with a dolly-steered trailer is presented. The unstable modes of the system is stabilized around circular equilibrium configurations using a gain-scheduled linear quadratic (LQ) controller together with a higher-level pure pursuit controller to enable path following of piecewise linear reference paths. The cascade controller is then used within a rapidly-exploring random tree (RRT) framework and the complete motion planning and control framework is demonstrated on a small-scale test vehicle.

    Second, a path following controller for a reversing truck with a dolly-steered trailer is proposed for the case when the obtained motion plan is kinematically feasible. The control errors of the system are modeled in terms of their deviation from the nominal path and a stabilizing LQ controller with feedforward action is designed based on the linearization of the control error model. Stability of the closed-loop system is proven by combining global optimization, theory from linear differential inclusions and linear matrix inequality techniques.

    Third, a systematic framework is presented for analyzing stability of the closed-loop system consisting of a controlled vehicle and a feedback controller, executing a motion plan computed by a lattice planner. When this motion planner is considered, it is shown that the closed-loop system can be modeled as a nonlinear hybrid system. Based on this, a novel method is presented for analyzing the behavior of the tracking error, how to design the feedback controller and how to potentially impose constraints on the motion planner in order to guarantee that the tracking error is bounded and decays towards zero.

    Fourth, a complete motion planning and control solution for a truck with a dolly-steered trailer is presented. A lattice-based motion planner is proposed, where a novel parametrization of the vehicle’s state-space is proposed to improve online planning time. A time-symmetry result is established that enhance the numerical stability of the numerical optimal control solver used for generating the motion primitives. Moreover, a nonlinear observer for state estimation is developed which only utilizes information from sensors that are mounted on the truck, making the system independent of additional trailer sensors. The proposed framework is implemented on a full-scale truck with a dolly-steered trailer and results from a series of field experiments are presented.

    Delarbeid
    1. Path tracking and stabilization for a reversing general 2-trailer configuration using a cascaded control approach
    Åpne denne publikasjonen i ny fane eller vindu >>Path tracking and stabilization for a reversing general 2-trailer configuration using a cascaded control approach
    2016 (engelsk)Inngår i: Intelligent Vehicles Symposium (IV), 2016 IEEE, Institute of Electrical and Electronics Engineers (IEEE), 2016, s. 1156-1161Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    In this paper a cascaded approach for stabilizationand path tracking of a general 2-trailer vehicle configurationwith an off-axle hitching is presented. A low level LinearQuadratic controller is used for stabilization of the internalangles while a pure pursuit path tracking controller is used ona higher level to handle the path tracking. Piecewise linearityis the only requirement on the control reference which makesthe design of reference paths very general. A Graphical UserInterface is designed to make it easy for a user to design controlreferences for complex manoeuvres given some representationof the surroundings. The approach is demonstrated with challengingpath following scenarios both in simulation and on asmall scale test platform.

    sted, utgiver, år, opplag, sider
    Institute of Electrical and Electronics Engineers (IEEE), 2016
    Emneord
    cascade control, control system synthesis, graphical user interfaces, linear quadratic control, mobile robot, path planning, piecewise linear techniques
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-130950 (URN)10.1109/IVS.2016.7535535 (DOI)000390845600183 ()978-1-5090-1821-5 (ISBN)978-1-5090-1822-2 (ISBN)
    Konferanse
    2016 IEEE Intelligent Vehicles Symposium, Gothenburg, Sweden, June 19-22, 2016
    Prosjekter
    iQMatic
    Forskningsfinansiär
    VINNOVA
    Tilgjengelig fra: 2016-09-01 Laget: 2016-09-01 Sist oppdatert: 2019-01-17bibliografisk kontrollert
    2. Motion planning for a reversing general 2-trailer configuration using Closed-Loop RRT
    Åpne denne publikasjonen i ny fane eller vindu >>Motion planning for a reversing general 2-trailer configuration using Closed-Loop RRT
    2016 (engelsk)Inngår i: 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Institute of Electrical and Electronics Engineers (IEEE), 2016, s. 3690-3697Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    Reversing with a dolly steered trailer configura- tion is a hard task for any driver without extensive training. In this work we present a motion planning and control framework that can be used to automatically plan and execute complicated manoeuvres. The unstable dynamics of the reversing general 2- trailer configuration with off-axle hitching is first stabilised by an LQ-controller and then a pure pursuit path tracker is used on a higher level giving a cascaded controller that can track piecewise linear reference paths. This controller together with a kinematic model of the trailer configuration is then used for forward simulations within a Closed-Loop Rapidly Exploring Random Tree framework to generate motion plans that are not only kinematically feasible but also include the limitations of the controller’s tracking performance when reversing. The approach is evaluated over a series of Monte Carlo simulations on three different scenarios and impressive success rates are achieved. Finally the approach is successfully tested on a small scale test platform where the motion plan is calculated and then sent to the platform for execution. 

    sted, utgiver, år, opplag, sider
    Institute of Electrical and Electronics Engineers (IEEE), 2016
    Serie
    Intelligent Robots and Systems, E-ISSN 2153-0866 ; 2016
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-134035 (URN)10.1109/IROS.2016.7759544 (DOI)000391921703107 ()9781509037629 (ISBN)9781509037612 (ISBN)9781509037636 (ISBN)
    Konferanse
    2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Daejeon, South Korea, October 9-14, 2016
    Prosjekter
    iQMatic
    Merknad

    Funding agencies: FFI/VINNOVA

    Tilgjengelig fra: 2017-01-19 Laget: 2017-01-19 Sist oppdatert: 2019-01-17bibliografisk kontrollert
    3. Path following control for a reversing general 2-trailer system
    Åpne denne publikasjonen i ny fane eller vindu >>Path following control for a reversing general 2-trailer system
    2016 (engelsk)Inngår i: 2016 IEEE 55TH CONFERENCE ON DECISION AND CONTROL (CDC), IEEE , 2016, s. 2455-2461Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    In order to meet the requirements for autonomous systems in real world applications, reliable path following controllers have to be designed to execute planned paths despite the existence of disturbances and model errors. In this paper we propose a Linear Quadratic controller for stabilizing a 2-trailer system with possible off-axle hitching around preplanned paths in backward motion. The controller design is based on a kinematic model of a general 2-trailer system including the possibility for off-axle hitching. Closed-loop stability is proved around a set of paths, typically chosen to represent the possible output from the path planner, using theory from linear differential inclusions. Using convex optimization tools a single quadratic Lyapunov function is computed for the entire set of paths.

    sted, utgiver, år, opplag, sider
    IEEE, 2016
    Serie
    IEEE Conference on Decision and Control, ISSN 0743-1546
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-138327 (URN)10.1109/CDC.2016.7798630 (DOI)000400048102102 ()978-1-5090-1837-6 (ISBN)
    Konferanse
    55th IEEE Conference on Decision and Control (CDC)
    Tilgjengelig fra: 2017-06-13 Laget: 2017-06-13 Sist oppdatert: 2019-01-17
    4. On stability for state-lattice trajectory tracking control
    Åpne denne publikasjonen i ny fane eller vindu >>On stability for state-lattice trajectory tracking control
    2018 (engelsk)Inngår i: 2018 Annual American Control Conference (ACC), IEEE, 2018, s. 5868-5875Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    In order to guarantee that a self-driving vehicle is behaving as expected, stability of the closed-loop system needs to be rigorously analyzed. The key components for the lowest levels of control in self-driving vehicles are the controlled vehicle, the low-level controller and the local planner.The local planner that is considered in this work constructs a feasible trajectory by combining a finite number of precomputed motions. When this local planner is considered, we show that the closed-loop system can be modeled as a nonlinear hybrid system. Based on this, we propose a novel method for analyzing the behavior of the tracking error, how to design the low-level controller and how to potentially impose constraints on the local planner, in order to guarantee that the tracking error is bounded and decays towards zero. The proposed method is applied on a truck and trailer system and the results are illustrated in two simulation examples.

    sted, utgiver, år, opplag, sider
    IEEE, 2018
    Serie
    American Control Conference (ACC), E-ISSN 2378-5861
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-152455 (URN)10.23919/ACC.2018.8430822 (DOI)978-1-5386-5428-6 (ISBN)978-1-5386-5427-9 (ISBN)978-1-5386-5429-3 (ISBN)
    Konferanse
    2018 Annual American Control Conference (ACC) June 27–29, 2018. Wisconsin Center, Milwaukee, USA
    Tilgjengelig fra: 2018-11-01 Laget: 2018-11-01 Sist oppdatert: 2019-01-17
  • 57.
    Lofwenmark, Andreas
    et al.
    Saab Aeronaut, Linkoping, Sweden.
    Nadjm-Tehrani, Simin
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska fakulteten.
    Fault and timing analysis in critical multi-core systems: A survey with an avionics perspective2018Inngår i: Journal of systems architecture, ISSN 1383-7621, E-ISSN 1873-6165, Vol. 87, s. 1-11Artikkel, forskningsoversikt (Fagfellevurdert)
    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.

  • 58.
    Lundahl, Kristoffer
    et al.
    Linköpings universitet, Institutionen för systemteknik. Linköpings universitet, Tekniska högskolan.
    Åslund, Jan
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Nielsen, Lars
    Linköpings universitet, Institutionen för systemteknik. Linköpings universitet, Tekniska högskolan.
    Investigating Vehicle Model Detail for Close to Limit Maneuvers Aiming at Optimal Control2011Konferansepaper (Annet vitenskapelig)
    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.

  • 59.
    Lundqvist, Erik
    Linköpings universitet, Institutionen för datavetenskap.
    Design Patterns for Service-Based Fault Tolerant Mechatronic Systems2011Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    In this Master thesis a new framework for achieving fault tolerance in mechatronic systems is studied. The framework is called service-based fault tolerant control and has the advantage of being completely decentralized and modular and therefore scales very well to large system sizes.

    First, a method is presented for designing the signal-flow architecture of mechatronic systems of real-life size and complexity. The result is a small set of generic building blocks in the form of design patterns, a concept that has gained widespread popularity in the field of software architecture.

    Best practises are then established for how each of the design patterns can be extended to support fault tolerance through diagnosis and reconfiguration according to the service-based framework. These extended design patterns can be used either to aid in the construction of new and more complex mechatronic systems or as a methodology for applying service-based fault tolerant control on large existing systems.

    The presented methods for designing and modelling large-scale mechatronic systems have the advantages of being applicable to a large class of mechatronic systems, being easy to apply without expert knowledge, as well as having the potential for being automated in the future.

    Finally, a case-study demonstrates how the new methods can be used to construct a fault tolerance architecture for a real-life automotive system currently used by Scania CV AB. As a part of this study a mathematical model for the system was also constructed and implemented. The model can be used for analysis during the development phase as well as troubleshooting in a repair workshop.

  • 60.
    Ländell, Karl-Rikard
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Wiksten Färnström, Axel
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    FPGA Implementation of a UPnP Media Renderer2011Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Actiwave AB delivers audio solutions for active speakers. One of the features is that audio can be streamed to the speakers over a local network connection. The module that provides this functionality is expensive. This thesis investigates if this can instead be achieved by taking advantage of the Spartan-6 FPGA on their platform, using part of it as a MicroBlaze soft processor on which a rendering device can be implemented. The thesis discusses design decisions such as selection and integration of operating system, UPnP framework and media decoder. A fully functional prototype application for a desktop computer was implemented, with the intention of porting it to the FPGA platform. There turned out to be too many compability issues though, so instead, a simpler renderer was implemented on the FPGA. Mp3 music files were successfully streamed to and decoded on the soft processor, but without fulfilling real-time constraints. The conclusion is that it is reasonable to implement a UPnP Media Renderer on the FPGA. Decoding in real-time can be an issue due to insufficient performance of the soft processor, but several possible solutions exist.

  • 61.
    Maghazeh, Arian
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska fakulteten.
    System-Level Design of GPU-Based Embedded Systems2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Modern embedded systems deploy several hardware accelerators, in a heterogeneous manner, to deliver high-performance computing. Among such devices, graphics processing units (GPUs) have earned a prominent position by virtue of their immense computing power. However, a system design that relies on sheer throughput of GPUs is often incapable of satisfying the strict power- and time-related constraints faced by the embedded systems.

    This thesis presents several system-level software techniques to optimize the design of GPU-based embedded systems under various graphics and non-graphics applications. As compared to the conventional application-level optimizations, the system-wide view of our proposed techniques brings about several advantages: First, it allows for fully incorporating the limitations and requirements of the various system parts in the design process. Second, it can unveil optimization opportunities through exposing the information flow between the processing components. Third, the techniques are generally applicable to a wide range of applications with similar characteristics. In addition, multiple system-level techniques can be combined together or with application-level techniques to further improve the performance.

    We begin by studying some of the unique attributes of GPU-based embedded systems and discussing several factors that distinguish the design of these systems from that of the conventional high-end GPU-based systems. We then proceed to develop two techniques that address an important challenge in the design of GPU-based embedded systems from different perspectives. The challenge arises from the fact that GPUs require a large amount of workload to be present at runtime in order to deliver a high throughput. However, for some embedded applications, collecting large batches of input data requires an unacceptable waiting time, prompting a trade-off between throughput and latency. We also develop an optimization technique for GPU-based applications to address the memory bottleneck issue by utilizing the GPU L2 cache to shorten data access time. Moreover, in the area of graphics applications, and in particular with a focus on mobile games, we propose a power management scheme to reduce the GPU power consumption by dynamically adjusting the display resolution, while considering the user's visual perception at various resolutions. We also discuss the collective impact of the proposed techniques in tackling the design challenges of emerging complex systems.

    The proposed techniques are assessed by real-life experimentations on GPU-based hardware platforms, which demonstrate the superior performance of our approaches as compared to the state-of-the-art techniques.

    Delarbeid
    1. General Purpose Computing on Low-Power Embedded GPUs: Has It Come of Age?
    Åpne denne publikasjonen i ny fane eller vindu >>General Purpose Computing on Low-Power Embedded GPUs: Has It Come of Age?
    2013 (engelsk)Inngår i: 13th International Conference on Embedded Computer Systems: Architectures, Modeling, and Simulation (SAMOS 2013), Samos, Greece, July 15-18, 2013., IEEE Press, 2013Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    In this paper we evaluate the promise held by low power GPUs for non-graphic workloads that arise in embedded systems. Towards this, we map and implement 5 benchmarks, that find utility in very different application domains, to an embedded GPU. Our results show that apart from accelerated performance, embedded GPUs are promising also because of their energy efficiency which is an important design goal for battery-driven mobile devices. We show that adopting the same optimization strategies as those used for programming high-end GPUs might lead to worse performance on embedded GPUs. This is due to restricted features of embedded GPUs, such as, limited or no user-defined memory, small instruction-set, limited number of registers, among others. We propose techniques to overcome such challenges, e.g., by distributing the workload between GPUs and multi-core CPUs, similar to the spirit of heterogeneous computation.

    sted, utgiver, år, opplag, sider
    IEEE Press, 2013
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-92626 (URN)10.1109/SAMOS.2013.6621099 (DOI)000332458100004 ()
    Konferanse
    SAMOS'13
    Tilgjengelig fra: 2013-05-14 Laget: 2013-05-14 Sist oppdatert: 2018-12-07
    2. Saving Energy without Defying Deadlines on Mobile GPU-based Heterogeneous Systems
    Åpne denne publikasjonen i ny fane eller vindu >>Saving Energy without Defying Deadlines on Mobile GPU-based Heterogeneous Systems
    Vise andre…
    2014 (engelsk)Inngår i: 2014 International Conference on Hardware/Software Codesign and System Synthesis, Association for Computing Machinery (ACM), 2014Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    With the advent of low-power programmable compute cores based on GPUs, GPU-equipped heterogeneous platforms are becoming common in a wide spectrum of industries including safety-critical domains like the automotive industry. While the suitability of GPUs for throughput oriented applications is well-accepted, their applicability for real-time applications remains an open issue. Moreover, in mobile/embedded systems, energy-efficient computing is a major concern and yet, there has been no systematic study on the energy savings that GPUs may potentially provide. In this paper, we propose an approach to utilize both the GPU and the CPU in a heterogeneous fashion to meet the deadlines of a real-time application while ensuring that we maximize the energy savings. We note that GPUs are inherently built to maximize the throughput and this poses a major challenge when deadlines must be satisfied. The problem becomes more acute when we consider the fact that GPUs are more energy efficient than CPUs and thus, a naive approach that is based on maximizing GPU utilization might easily lead to infeasible solutions from a deadline perspective.

    sted, utgiver, år, opplag, sider
    Association for Computing Machinery (ACM), 2014
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-112689 (URN)10.1145/2656075.2656097 (DOI)978-1-4503-3051-0 (ISBN)
    Konferanse
    International Conference on Hardware/Software Codesign and System Synthesis (CODES+ISSS 2014), New Delhi, India, October 12-17, 2014
    Tilgjengelig fra: 2014-12-08 Laget: 2014-12-08 Sist oppdatert: 2018-12-07bibliografisk kontrollert
    3. Perception-aware power management for mobile games via dynamic resolution scaling
    Åpne denne publikasjonen i ny fane eller vindu >>Perception-aware power management for mobile games via dynamic resolution scaling
    Vise andre…
    2015 (engelsk)Inngår i: 2015 IEEE/ACM INTERNATIONAL CONFERENCE ON COMPUTER-AIDED DESIGN (ICCAD), IEEE , 2015, s. 613-620Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    Modern mobile devices provide ultra-high resolutions in their display panels. This imposes ever increasing workload on the GPU leading to high power consumption and shortened battery life. In this paper, we first show that resolution scaling leads to significant power savings. Second, we propose a perception-aware adaptive scheme that sets the resolution during game play. We exploit the fact that game players are often willing to trade quality for longer battery life. Our scheme uses decision theory, where the predicted user perception is combined with a novel asymmetric loss function that encodes users' alterations in their willingness to save power.

    sted, utgiver, år, opplag, sider
    IEEE, 2015
    Serie
    ICCAD-IEEE ACM International Conference on Computer-Aided Design, ISSN 1933-7760
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-124543 (URN)10.1109/ICCAD.2015.7372626 (DOI)000368929600084 ()978-1-4673-8388-2 (ISBN)
    Konferanse
    Computer-Aided Design (ICCAD), 2015 IEEE/ACM International Conference on 2-6 Nov. 2015 Austin, TX
    Tilgjengelig fra: 2016-02-02 Laget: 2016-02-02 Sist oppdatert: 2018-12-07
    4. Latency-Aware Packet Processing on CPU-GPU Heterogeneous Systems
    Åpne denne publikasjonen i ny fane eller vindu >>Latency-Aware Packet Processing on CPU-GPU Heterogeneous Systems
    Vise andre…
    2017 (engelsk)Inngår i: DAC '17 Proceedings of the 54th Annual Design Automation Conference 2017, New York, NY, USA: Association for Computing Machinery (ACM), 2017Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    In response to the tremendous growth of the Internet, towards what we call the Internet of Things (IoT), there is a need to move from costly, high-time-to-market specific-purpose hardware to flexible, low-time-to-market general-purpose devices for packet processing. Among several such devices, GPUs have attracted attention in the past, mainly because the high computing demand of packet processing applications can, potentially, be satisfied by these throughput-oriented machines. However, another important aspect of such applications is the packet latency which, if not handled carefully, will overshadow the throughput benefits. Unfortunately, until now, this aspect has been mostly ignored. To address this issue, we propose a method that considers the variable bit rate of the traffic and, depending on the current rate, minimizes the latency, while meeting the rate demand. We propose a persistent kernel based software architecture to overcome the challenges inherent in GPU implementation like kernel invocation overhead, CPU-GPU communication and memory access overhead. We have chosen packet classification as the packet processing application to demonstrate our technique. Using the proposed approach, we are able to reduce the packet latency on average by a factor of 3.5, compared to the state-of-the-art solutions, without any packet drop.

    sted, utgiver, år, opplag, sider
    New York, NY, USA: Association for Computing Machinery (ACM), 2017
    Serie
    Design Automation Conference DAC, ISSN 0738-100X
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-141212 (URN)10.1145/3061639.3062269 (DOI)000424895400129 ()2-s2.0-85023612665 (Scopus ID)978-1-4503-4927-7 (ISBN)
    Konferanse
    54th ACM/EDAC/IEEE Design Automation Conference (DAC), Austin, TX, USA, June 18-22, 2017
    Tilgjengelig fra: 2017-09-27 Laget: 2017-09-27 Sist oppdatert: 2018-12-07bibliografisk kontrollert
  • 62.
    Manjunath, Adithya
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska högskolan.
    WCDMA RUE Verification Method2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Exchange of information in the present world has witnessed a significant progress owing to modern telecommunication technologies, advanced gadgets and powerful computers. Wireless networks are the most popular choice for the obvious reason of connecting people on the move. Cellular technology provides a wide area connectivity and potential of generating higher revenues to the service provider. Universal Mobile Telecommunication System (UMTS) is a 3rd Generation (3G) technology that offers a high speed data access besides conventional voice service. 3rd Generation Partnership Project (3GPP) committee defines the standards for UMTS technology. UMTS uses Wideband Code Division Multiple Access (WCDMA) for radio transmission.

    A cellular network infrastructure houses an access point termed as base station to enable radio connectivity to the mobile devices. The base station hardware requires validation to determine its performance and limitation. Specialized hardware is used by Ericsson for testing baseband processing of base station which can emulate multiple mobile terminals. This hardware resembles a Real-time User Equipment (RUE) which is capable of simulating different scenarios of wireless transmission and modes of mobile devices. This test infrastructure encapsulates Digital Signal Processors (DSPs), Field-Programmable Gate Arrays (FPGAs) and other components. One FPGA is used for generating the data needed for transmission to the base station. FPGA performs the physical layer chip rate processing where all the information carrying data and control signals are represented in radio frames. The purpose of this thesis is formal verification of this FPGA based on Hardware Description Language (HDL) simulator.

    Specman is a Cadence tool used to create test benches for verifying FPGA and executes the test cases along with a HDL simulator. It provides a standard for defining, compiling and executing a test environment developed in e language. This project uses Specman based verification of the uplink chip rate processing of the FPGA which includes many unit level signal processing blocks. The test bench autonomously generates the necessary inputs, predicts the output using a reference model, monitors the outputs and compares it with predicted output. The sequence of generation of inputs is designed to simulate specific cases defined in 3GPP specification. The device timing, control and configuration information needed is precisely included in test environment. The test results are summarized with coverage information on different combination of inputs tested or occurrence of certain events.

  • 63.
    Meher, Pramod Kumar
    et al.
    Independent Hardware Consultant.
    Chang, Chip-Hong
    Nanyang Technological University, Singapore, Singapore.
    Gustafsson, Oscar
    Linköpings universitet, Institutionen för systemteknik, Datorteknik. Linköpings universitet, Tekniska fakulteten.
    Vinod, A.P.
    Nanyang Technological University, Singapore, Singapore.
    Faust, Mattias
    mfnet gmbh, Switzerland.
    Shift‐Add Circuits for Constant Multiplications2017Inngår i: Arithmetic Circuits for DSP Applications / [ed] Pramod Kumar Meher, Thanos Stouraitis, John Wiley & Sons, 2017, s. 33-76Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    The optimization of shift‐and‐add network for constant multiplications is found to have great potential for reducing the area, delay, and power consumption of implementation of multiplications in several computation‐intensive applications not only in dedicated hardware but also in programmable computing systems. To simplify the shift‐and‐add network in single constant multiplication (SCM) circuits, this chapter discusses three design approaches, including direct simplification from a given number representation, simplification by redundant signed digit (SD) representation, and simplification by adder graph. Examples of the multiple constant multiplication (MCM) methods are constant matrix multiplication, discrete cosine transform (DCT) or fast Fourier transform (FFT), and polyphase finite impulse response (FIR) filters and filter banks. The given constant multiplication methods can be used for matrix multiplications and inner‐product; and can be applied easily to image/video processing and graphics applications. The chapter further discusses some of the shortcomings in the current research on constant multiplications, and possible scopes of improvement.

  • 64.
    Murugesan, Somasekar
    Linköpings universitet, Institutionen för systemteknik, Datorteknik. Linköpings universitet, Tekniska högskolan.
    Benchmarking of Sleipnir DSP Processor, ePUMA Platform2011Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Choosing a right processor for an embedded application, or designing a new pro-cessor requires us to know how it stacks up against the competition, or sellinga processor requires a credible communication about its performance to the cus-tomers, which means benchmarking of a processor is very important. They arerecognized world wide by processor vendors and customers alike as the fact-basedway to evaluate and communicate embedded processor performance. In this the-sis, the benchmarking of ePUMA multiprocessor developed by the Division ofComputer Engineering, ISY, Linköping University, Sweden will be described indetails. A number of typical digital signal processing algorithms are chosen asbenchmarks. These benchmarks have been implemented in assembly code withtheir performance measured in terms of clock cycles and root mean square errorwhen compared with result computed using double precision. The ePUMA multi-processor platform which comprises of the Sleipnir DSP processor and Senior DSPprocessor was used to implement the DSP algorithms. Matlab inbuilt models wereused as reference to compare with the assembly implementation to derive the rootmean square error values of different algorithms. The execution time for differentDSP algorithms ranged from 51 to 6148 clock cycles and the root mean squareerror values varies between 0.0003 to 0.11.

  • 65.
    Nilsson, Mattias
    Linköpings universitet, Institutionen för systemteknik, Datorseende. Linköpings universitet, Tekniska högskolan.
    Evaluation of Computer Vision Algorithms Optimized for Embedded GPU:s.2014Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The interest of using GPU:s as general processing units for heavy computations (GPGPU) has increased in the last couple of years. Manufacturers such as Nvidia and AMD make GPU:s powerful enough to outrun CPU:s in one order of magnitude, for suitable algorithms. For embedded systems, GPU:s are not as popular yet. The embedded GPU:s available on the market have often not been able to justify hardware changes from the current systems (CPU:s and FPGA:s) to systems using embedded GPU:s. They have been too hard to get, too energy consuming and not suitable for some algorithms. At SICK IVP, advanced computer vision algorithms run on FPGA:s. This master thesis optimizes two such algorithms for embedded GPU:s and evaluates the result. It also evaluates the status of the embedded GPU:s on the market today. The results indicates that embedded GPU:s perform well enough to run the evaluatedd algorithms as fast as needed. The implementations are also easy to understand compared to implementations for FPGA:s which are competing hardware.

  • 66.
    Nilsson, Sara
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska fakulteten.
    Buffoni, Lena
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska fakulteten.
    Sandahl, Kristian
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska fakulteten.
    Johansson, Hanna
    Linköpings universitet, Institutionen för datavetenskap, Interaktiva och kognitiva system. Linköpings universitet, Tekniska fakulteten.
    Tahir Sheikh, Bilal
    Empirical Study of Requirements Engineering in Cross Domain Development2018Inngår i: DS 92: Proceedings of the DESIGN 2018 15th International Design Conference / [ed] Dorian Marjanović, Mario Štorga, Stanko Škec, Nenad Bojčetić and Neven Pavković, Glasgow: The Design Society , 2018, Vol. 92, s. 857-868Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Shortened time-to-market cycles and increasingly complex systems are just some of the challenges faced by industry. The requirement engineering process needs to adapt to these challenges in order to guarantee that the end product fulfils the customer expectations as well as the necessary safety norms. The goal of this paper is to investigate the way engineers work in practice with the requirement engeneering processes at different stages of the development, with a particular focus on the use of requirements in cross domain development and to compare this to the existing theory in the domain.

  • 67.
    Norin, Niklas
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    The Telecommuting Software Developer2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This thesis designs, and partially implements, an architecture for running an embedded Linux application on a regular PC, without access to the target device. This thesis shows how a standard Linux User space filesystem, in the right environment, can be used to emulate the most common User space GPIO interface in Linux, SysFS. Furthermore, this thesis sets up a template for how this architecture can be used to run both the embedded application and an application emulating the connected hardware.

  • 68.
    Ocklind, Henrik
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Driver Circuit for an Ultrasonic Motor2013Independent thesis Advanced level (degree of Master (One Year)), 20 poäng / 30 hpOppgave
    Abstract [en]

    To make a camera more user friendly or let it operate without an user the camera objective needs to be able to put thecamera lens in focus. This functionality requires a motor of some sort, due to its many benefits the ultrasonic motor is apreferred choice. The motor requires a driving circuit to produce the appropriate signals and this is what this thesis is about.Themain difficulty that needs to be considered is the fact that the ultrasonic motor is highly non-linear.This paper will give a brief walk through of how the ultrasonic motor works,its pros and cons and how to control it. How thedriving circuit is designed and what role the various components fills. The regulator is implemented in C-code and runs on amicro processor while the actual signal generation is done on a CPLD. The report ends with a few suggestions of how toimprove the system should the presented solution not perform at a satisfactory level.

  • 69.
    Olsson, Joel
    et al.
    Linköpings universitet, Institutionen för systemteknik.
    Asante, Junior
    Linköpings universitet, Institutionen för systemteknik, Elektroniska Kretsar och System.
    Using Node-Red to Connect Patient, Staff and Medical Equipment2016Independent thesis Basic level (university diploma), 10,5 poäng / 16 hpOppgave
    Abstract [en]

    The emergency departments in Region Östergötland use pen and paper to a large extent when recording emergency care procedures and measurements. During treatment the patient should be the main focus. Because of this, recording of measurements done could be delayed or in worst case forgotten during stressful situations.

    The proposal of this project is the development of a prototype that tries to make the administrative work a passive procedure rather than an active one. The system developed uses a Raspberry Pi, along with Node-Red, which connects predefined patient data and medical records, with the clinical staff tending the patient. All these connections are initiated by mainly using RFID technology.

    The conclusion made with the developed system is that it should unload the staff with the recording of data and that it helps make a data logging a more passive work than today’s used methods. Along with a process that is easier to operate, the time spent on administrative work could be reduced with the proposed system.

  • 70.
    Park, Taeju
    et al.
    Univ Michigan, MI 48109 USA.
    Samii, Soheil
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska fakulteten. Gen Motors RandD, MI USA.
    Shin, Kang G.
    Univ Michigan, MI 48109 USA.
    Design Optimization of Frame Preemption in Real-Time Switched Ethernet2019Inngår i: 2019 DESIGN, AUTOMATION and TEST IN EUROPE CONFERENCE and EXHIBITION (DATE), IEEE , 2019, s. 420-425Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Switched Ethernet has been, and will also be increasingly common in current and future real-time and embedded systems. The IEEE 802.1 working group has recently developed standards and technologies, commonly referred to as Time-Sensitive Networking (TSN), to enhance switched Ethernet with timeliness and dependability. We address, for the first time, the synthesis problem for the TSN frame preemption standards IEEE 802.3br-2016 and 802.1Qbu-2016 by introducing two new configuration parameters: flow to queue and queue to Express/Preemptable MAC interface assignments. We present an optimization framework to determine these configuration parameters with reliability as the optimization goal. Our proposed framework is shown to outperform commonly used priority-assignment as well as intuitive approaches.

  • 71.
    Patriksson, Alfred
    Linköpings universitet, Institutionen för systemteknik, Datorteknik.
    Radio signal DOA estimation: Implementing radar signal direction estimation on an FPGA.2019Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This master’s thesis covers the design and implementation of a monopulse directionof arrival (DOA) estimation algorithm on an FPGA. The goal is to implement a complete system that is capable of estimating the bearing of an incident signal. In order to determine the estimate quality both a theoretical and practical noise analysis of the signal chain is performed.

    Special focus is placed on the statistical properties of the transformation from I/Q-demodulated signals with correlated noise to a polar representation. The pros and cons for three different methods of calculating received signal phasors are also covered.The system is limited to two receiving channels which constrains this report to a 2D analysis. In addition the used hardware is limited to C-band signals. We show that an FPGA implementation of monopulse techniques is definitely viable and that an SNR higher than ten dB allows for a gaussian approximation of the polar representationof an I/Q signal.

  • 72.
    Persson, Anders
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska högskolan.
    A TDMA Module for Waterborne Communication with Focus on Clock Synchronization2014Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    This bachelor thesis has been carried out at the company Didamus which is located in Mjärdevi, Linköping. The company is currently developing a dive-console which aims to take the scuba diving experience to a whole new level and also to make scuba diving more secure.

    An assembly of scuba divers that can communicate with each other during a dive session might be the difference between life and death. Many seas around the world have muddy water which means poor visibility. In each situation a computer providing a scuba diver with information about others connected to the network, hazardous accidents can possibly be avoided. 

    The network itself consist of 10 nodes that need a network protocol which provides stability and reliability for every participant. The nodes themselves have a distributed responsibility to make the network reliable. The type of network implemented was a regular Time Division Multiple Access (TDMA) network where different nodes were given permission to access the medium in different instances of time. A global reference of time is always needed in a TDMA network to make it function properly. In a typical TDMA network a GPS-service gives each and every node information about the global time.  Unfortunately, GPS-services do not work well in water so a Master-Slave method was used instead. The master provides the rest of the nodes in the network with a global time reference. After a successful reception of a global time reference, the slave will be granted access to the network.

    The communication between the nodes is based on ultrasonic waves propagating in the water. The velocity of ultrasonic waves in water is only 1500 meters per second, explained in Discovery of Sound in the Sea by University of Rhode Island, which is a relatively slow signal speed. With the slow velocity taken into account an efficient TDMA protocol was developed, to perform communication under water. 

  • 73.
    Pettersson, Tobias
    Linköpings universitet, Institutionen för systemteknik, Datorteknik. Linköpings universitet, Tekniska högskolan.
    Synchronization of flywheel position between autonomous devices2012Independent thesis Advanced level (degree of Master (One Year)), 20 poäng / 30 hpOppgave
    Abstract [en]

    More computing power will be required in Scania’s future engine control units. Calculations is therefore needed to be performed on new hardware such as an FPGA. One problem that arises is synchronization of flywheelposition. This master thesis examines the opportunities existing Scania hardware has to perform synchronization of flywheel position. Different concepts for synchronization have been developed and compared with each other. One of the concepts have been implemented and made possible witha PCB-adapter. The results show that synchronization is possible within given real-time requirements. Finally, an analysis to series production has been made. It show the challenges that an FPGA will face when integrated into a future engine control unit.

  • 74.
    Ribeiro, Luis
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell Produktion. Linköpings universitet, Tekniska fakulteten.
    The design, deployment, and assessment of industrial agent systems2015Inngår i: Industrial Agents: Emerging Applications of Software Agents in Industry / [ed] Paulo Leitao and Stamatis Karnouskos, Amsterdam, Netherlands: Elsevier, 2015, 1st ed., s. 45-63Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    Agent based systems have been explored, if not practically, at least conceptually, in a wide range of domains. The notion of agent has taken, also, many shapes and meanings according to the application area. These have ranged from pure computational applications, such as UNIX daemons, Internet crawlers, optimization algorithms, etc; to embodied agents as in mobile robotics. The notion of cyber-physical system has been very recently coined to denote the next generation of embedded systems. Unlike an embedded system, a cyber-physical system is designed from scratch to promote the symbiosis and fusion between a physical element, its controller, and its abstract or logical representation/existence. To an enormous extent the concept echoes the idea of embodiment (Pfeifer, Lungarella & Iida 2007), whereby the body shapes the cognitive abilities of its control gear, and self-organization (Holland & Melhuish 1999), in the sense that a resilient whole results from the collective interactions of many parts. Some rather similar principles have been the basis for Holonic Manufacturing Systems (HMS) (Bussmann & Mcfarlane 1999), Bionic Manufacturing Systems (BMS) (Ueda 1992), Evolvable Assembly Systems (EAS) (Onori 2002) and an overwhelming number of industrial agent based architectures that have followed them (Van Brussel et al. 1998; Leitao, Colombo & Restivo 2005; Barata 2003; Lastra 2004; Shen et al. 2006; Marik & Lazansky 2007; Vrba et al. 2011; Leitão 2009; Monostori, Váncza & Kumara 2006).

    It is therefore safe to assert that industrial agent systems are a preceding, probably more restricted, case of cyber-physical systems.

    Although each application area has its specific challenges arguably, the design, deployment and assessment of industrial agent systems are particularly complex. Given the multidisciplinary nature of today's industrial systems, their cyber-physical realization entails challenges that range from pure computer science and embedded controller design to production optimization and sustainability.

    The main challenges comprising the design, deployment and assessment of industrial agent-based systems are therefore examined.

    Multiagent Systems (MAS) have been widely known as the base for inherent robust and available systems and there are many characteristics (Wooldridge & Jennings 1994; Wooldridge & Jennings 1995) such as autonomy, social-ability, proactive response, reactivity, self-organization, etc; which have been identified as core ingredients for the MAS reliability.

    However, to call "agent" to a software abstraction and create a system based on these abstractions is not a guarantee that the system will exhibit the expected characteristics. Unfortunately this misconception is quite common.

    There have been significant international and industrial efforts in addressing the different design, deployment and assessment challenges. The reader is naturally referred to the contents of this book to learn about the latest results and technical details. Previous international projects are not limited to but include: SIRENA - early development of a devices profiles for web services (DPWS) stack (Jammes & Smit 2005; Bohn, Bobek & Golatowski 2006) and subsequent project SODA - focusing on the development of a service based ecosystem using DPWS, Inlife - focusing in service oriented diagnosis of distributed intelligent systems (Barata, Ribeiro & Colombo 2007), SOCRADES - investigating the creation of new methodologies, technologies and tools for the modelling, design, implementation and operation of networked hardware/software systems embedded in smart physical objects (De Souza et al. 2008), AESOP - tackling web service-oriented process monitoring and control (Karnouskos et al. 2010), GRACE - exploring process and quality control integration using a MAS framework (Stroppa et al. 2012) and IDEAS - focusing in instant deployment of agentified components (Ribeiro et al. 2011a).      

    The subsequent details are therefore organized to first highlight the commonest structural arrangements considered in current agent architectures and more specifically on bringing some context on their potential applications and limitations. Secondly, since emerging architectures are increasingly inspired by concepts and methods from the complexity sciences, the gaps between them and the concrete instantiation of industrial MAS are discussed. The presentation of the design challenges and opportunities follows as well as the conventional deployment approaches. Finally, the impact of MAS design is discussed from a system validation perspective.

  • 75.
    Ribeiro, Luis
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell Produktion. Linköpings universitet, Tekniska fakulteten.
    Barata, Jose
    Uninova - CTS, Departamento de Engenharia Electrotécnica, Faculdade de Ciências e Tecnologia, Portugal.
    Onori, Mauro
    KTH, Royal Institute of Technology, Stockholm, Sweden.
    Hoos, Johannes
    Festo AG & Co. KG, Esslingen, Germany.
    Industrial Agents for the Fast Deployment of Evolvable Assembly Systems2015Inngår i: Industrial Agents: Emerging Applications of Software Agents in Industry / [ed] Paulo Leitao and Stamatis Karnouskos, Amsterdam, Netherlands: Elsevier, 2015, 1st ed., s. 301-321Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    The current manufacturing scenario is characterized by high market unpredictability. Agility is therefore a central challenge for modern companies that need to understand and be proactive towards their product offer in respect to “what is offered, when it is offered, where, how and by whom” (Brown & Bessant 2003).

    The “what” and the “when” are particularly relevant to the research in emerging paradigms as they account for variety, customization and volume; and timing, speed and seasonality (Brown & Bessant 2003).

    In this scenario, several design approaches and models have been proposed in the last decade to enable re-configurability and subsequently enhance the companies’ ability to adjust their offer in nature and time.

    From a paradigmatic point of view research has concentrated on the organizational structure of the shop-floor and the associated controls aspects. Concepts like Reconfigurable Manufacturing Systems (RMS) (Koren & Shpitalni 2010) and Fractal Factories (FF) (Montreuil 1999) support the physical construction of production systems by regulating their layout and making a few assumptions on their logical organization. On the other hand, concepts like Bionic Manufacturing Systems (BMS)(Ueda 1992), Holonic Manufacturing Systems (HMS)(Van Brussel et al. 1998), Evolvable Assembly Systems (Ribeiro et al. 2010) essentially provide the theoretical guidelines for the logical/computational organization of the system (see (Tharumarajah 1996) for a comparison between BMS, HMS and FF and (Setchi & Lagos 2004) for the rationale supporting the shift from Dedicated Lines to Flexible Manufacturing System and finally RMS).

    While these paradigms provide the conceptual framework and the main design guidelines their actual interpretation and implementation has led to a wider set of architectures (Monostori, Váncza & Kumara 2006; Leitão 2009; Parunak 2000; Pěchouček & Mařík 2008).

    These architectures align the high-level principles with the technological offer and limitations while seeking to address the re-configurability requirements of (Mehrabi, Ulsoy & Koren 2000; Rösiö & Säfsten 2013):

    • module mobility – modules are easy and quick to move and install;
    • “diagnosability” – it is quick to identify the sources of quality and reliability problems;
    • “integrability” – modules are easy to integrate into the rest of the system.
    • “convertibility” – it is easy and quick to switch between existing products and it is easy to adapt the system to future products;
    • scalability – it is easy to enlarge and downsize the production system;
    • “automatibility” – a dynamic level of automation is enabled;
    • modularity – all system elements are designed to be modular;
    • customization – the capability and flexibility of the production system is designed according to the products to be produced in the system.

    Instant deployment, as addressed in the present chapter directly addresses mobility, “integrability”, “convertibility”, scalability and customization. Mechatronic modularity is a prerequisite and is enforced by the proposed architecture and the considered modular design. “Diagnosability” was not specifically tackled.

    In this context, the chapter analyses the agent-based architecture related with the Instantly Deployable Evolvable Assembly System (IDEAS) project that is inspired by the Evolvable Assembly System (EAS) paradigm (Ribeiro et al. 2010) as a mechanism to enable fast deployment of mechatronic modules. EAS advocates the use of process-oriented modules and envisions the production system as a collection of processes and the associated interacting agents.

    The architecture and the related test cases are used to draw the main lessons learned in respect to technological and conceptual implications.

    In this context, the remainder of this text is organized as follows: section 1.1 discusses the main deployment challenges, section 1.2 details the reference architecture and associated concepts, section 1.3 presents the principal implementation decisions, section 1.4 features the main lessons learned, sections 1.5 discusses the benefits of the proposed approach and finally section 1.6 reflects on the main conclusions.

  • 76.
    Ribeiro, Luis
    et al.
    CTS, Uninova, Dep. de Eng. Electrotécnica , Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
    Barata, José
    CTS, Uninova, Dep. de Eng. Electrotécnica , Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
    Pimentão, João
    CTS, Uninova, Dep. de Eng. Electrotécnica , Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
    Where evolvable production systems meet complexity science2011Inngår i: Proceedings ISAM 2011. IEEE International Symposium on Assembly and Manufacturing (ISAM), 25-27 May, Tampere, Finland, IEEE , 2011, s. 1-6Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Modern control approaches are either designated as complex or tackle complex systems. The concept of Evolvable Production System (EPS) entails an iterative system design/control loop that supports system Adaptation and Evolution. Both concepts are borrowed from natural systems and, if properly instantiated and explored for the sake of production systems, may come to include a set of self-organizing and emergent process. One of the main challenges in EPS research is to frame these developing natural concepts and set them in a Mechatronic Agent-based framework. Such an approach also brings into the equation the possibility to handle and, potentially, exploit emergent behaviour. Inevitably, the coping of dynamically evolving setups with unforecasted behaviours raises the complexity issue quite substantially, hence the need to begin to analyse the EPS systems as Complex Systems. This paper provides an introduction to the context of Complex Systems, in particular about the self-organization and emergence components, and, from this integration, details how the bridging of the technological and functional challenges is being adopted within EPS. The work is based on assembly systems built within the framework of several European projects, including EUPASS, IPROMS and IDEAS. Finally, the article will provide with an initial evaluation and critical review of the complexity approach.

  • 77.
    Ribeiro, Luis
    et al.
    Faculty of Sciences and Technology, Universidade Nova de Lisboa, Portugal.
    Barata, José
    Faculty of Sciences and Technology, Universidade Nova de Lisboa, Portugal.
    Silverio, Nelson
    Faculty of Sciences and Technology, Universidade Nova de Lisboa, Portugal.
    Maintenance management and operational support as services in reconfigurable manufacturing systems2009Inngår i: Information Control Problems in Manufacturing / [ed] Natalia Bakhtadze and Alexandre Dolgui, 2009, Vol. 13, s. 1778-1783Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Emergent architectures and paradigms targeting reconfigurable manufacturing systems increasingly rely in intelligent models to maximize the robustness and responsiveness of modern installations. Although intelligent behaviour significantly minimizes the occurrence of faults and breakdowns it does not exclude them nor can prevent equipment’s normal wear. Adequate maintenance is fundamental to extend equipments’ life cycle. It is of major importance the ability of each intelligent device to take an active role in maintenance support. This paper proposes a maintenance architecture supporting maintenance teams’ management and offering contextualized operational support. All the functionalities hosted by the architecture are offered to the remaining system as network services. Any intelligent module, implementing the services’ interface, can report diagnostic, prognostic and maintenance recommendations that enable the core of the platform to decide on the best course of action.

  • 78.
    Ringenson, Josefin
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system.
    Efficiency of CNN on Heterogeneous Processing Devices2019Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    In the development of advanced driver assistance systems, computer vision problemsneed to be optimized to run efficiently on embedded platforms. Convolutional neural network(CNN) accelerators have proven to be very efficient for embedded camera platforms,such as the ones used for automotive vision systems. Therefore, the focus of this thesisis to evaluate the efficiency of a CNN on a future embedded heterogeneous processingdevice.

    The memory size in an embedded system is often very limited, and it is necessary todivide the input into multiple tiles. In addition, there are power and speed constraintsthat needs to be met to be able to use a computer vision system in a car. To increaseefficiency and optimize the memory usage, different methods for CNN layer fusion areproposed and evaluated for a variety of tile sizes.

    Several different layer fusion methods and input tile sizes are chosen as optimal solutions,depending on the depth of the layers in the CNN. The solutions investigated inthe thesis are most efficient for deep CNN layers, where the number of channels is high.

  • 79.
    Rosenvik, Niclas
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska fakulteten.
    Study of the Time Triggered Ethernet Dataflow2015Independent thesis Basic level (degree of Bachelor), 10,5 poäng / 16 hpOppgave
    Abstract [en]

    In recent years Ethernet has cought the attention of the real-time community. the main reason for this is that it has a high data troughput, 10Mbit/s and higher, and good EMI characteristics. As a protocol that might be used in real-time anvironments such as control systems for cars etc, it seems to fulfil the rquirements. TTEthernet is a TDMA extention to normal Ethnernet, designed to meet the hard deadlines required by real-time networks. This thesis describes how TTEthernet handles frames and the mathematical formulas to calculate shuffle delay of frames in such a network. Open problems related to TTEthernet are also discussed.

  • 80.
    Rudol, Piotr
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Artificiell intelligens och integrerade datorsystem. Linköpings universitet, Tekniska fakulteten.
    Doherty, Patrick
    Linköpings universitet, Institutionen för datavetenskap, Artificiell intelligens och integrerade datorsystem. Linköpings universitet, Tekniska fakulteten.
    Bridging Reactive and Control Architectural Layers for Cooperative Missions Using VTOL Platforms2017Inngår i: 2017 25TH INTERNATIONAL CONFERENCE ON SYSTEMS ENGINEERING (ICSENG), IEEE , 2017, s. 21-32Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper we address the issue of connecting abstract task definitions at a mission level with control functionalities for the purpose of performing autonomous robotic missions using multiple heterogenous platforms. The heterogeneity is handled by the use of a common vocabulary which consists of parametrized tasks such as fly-to, take-off, scan-area, or land. Each of the platforms participating in a mission supports a subset of the tasks by providing their platform-specific implementations. This paper presents a detailed description of an approach for implementing such platform-specific tasks. It is achieved using a flight-command based interface with setpoint generation abstraction layer for vertical take-off and landing platforms. We show that by using this highly expressive and easily parametrizable way of specifying and executing flight behaviors it is straightforward to implement a wide range of tasks. We describe the method in the context of a previously described robotics architecture which includes mission delegation and execution system based on a task specification language. We present results of an experimental flight using the proposed method.

  • 81.
    Sandstedt, Adam
    Linköpings universitet, Institutionen för systemteknik, Datorteknik. Linköpings universitet, Tekniska högskolan.
    Implementation and analysis of a virtual platform based on an embedded system2014Independent thesis Advanced level (degree of Master (Two Years)), 300 hpOppgave
    Abstract [en]

    The complexity among embedded systems has increased dramatically in recent years. During the same time has the capacity of the hardware grown to astonishing levels. These factors have contributed to that software has taken a leading role and time-consuming role in embedded system development.Compared with regular software development, embedded development is often more restrained by factors such as hardware performance and testing capability. A solution to some of these problem has been proposed and that is a concept called virtual platforms. By emulating the hardware in a software environment, it is possible to avoid some of the problems associated with embedded software development. For example is it possible to execute a system faster than in reality and to provide a more controllable testing environment. This thesis presents a case study of an application specific virtual platform. The platform is based on already existing embedded system that is located in an industrial control system.  The virtual platform is able to execute unmodified application code at a speed twice of the real system, without causing any software faults. The simulation can also be simulated at even higher speed if some accuracy losses are regarded as acceptable.The thesis presents some tools and methods that can be used to model hardware on a functional level in an software environment. The thesis also investigates the accuracy of the virtual platform by comparing it with measurements from the physical system. In this case are the measurements mainly focused of the data transactions in a controller area network bus (CAN).

  • 82.
    Sandvik, Fredrik
    et al.
    Linköpings universitet, Institutionen för systemteknik, Datorteknik. Linköpings universitet, Tekniska fakulteten.
    Tingstam, Olle
    Linköpings universitet, Institutionen för systemteknik, Datorteknik. Linköpings universitet, Tekniska fakulteten.
    Design and Prototyping of a Scalable Contactor Platform Adapted to State-of-the-Art Functions2015Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    The goal of the thesis is to investigate and propose a new design for a contactor platform, both in terms of hardware and embedded software, which incorporates support to implement new state-of-the-art functions. The platform must support a wide range of contactors from basic ones with only core functions to advanced contactors using modern microcontrollers to provide efficient, quick and reliable operation.

     

    Further, a significant focus of the thesis is on the interaction between electrical engineering and computer engineering. The electronics needs to interact seamlessly with a microcontroller running a versatile software to provide industry-leading performance. To achieve this, the software and hardware is evaluated with focus to develop an optimal platform.

     

    The proposed embedded software uses development techniques rarely used in embedded applications such as UML code generation, compile-time initiation of objects and an object-oriented design, while maintaining the performance of traditional embedded programming. The thesis also provides suggestions to hardware changes to further improve to the contactor’s operation.

  • 83.
    Savic, Vladimir
    et al.
    Technical University of Madrid, Spain.
    Athalye, Akshay
    Stony Brook University, USA.
    Bolic, Miodrag
    University of Ottawa, Canada.
    Djuric, Petar M.
    Stony Brook University, USA.
    Particle filtering for indoor RFID tag tracking2011Inngår i: Proc. of IEEE Statistical Signal Processing Workshop (SSP), 2011, s. 193-196Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, we propose a particle filtering (PF) method for indoor tracking using radio frequency identification (RFID) based on aggregated binary measurements. We use an Ultra High Frequency (UHF) RFID system that is composed of a standard RFID reader, a large set of standard passive tags whose locations are known, and a newly designed, special semi-passive tag attached to an object that is tracked. This semi-passive tag has the dual ability to sense the backscatter communication between the reader and other passive tags which are in its proximity and to communicate this sensed information to the reader using backscatter modulation. We refer to this tag as a sense-a-tag (ST). Thus, the ST can provide the reader with information that can be used to determine the kinematic parameters of the object on which the ST is attached. We demonstrate the performance of the method with data obtained in a laboratory environment.

  • 84.
    Schneider, Frank E.
    et al.
    Fraunhofer-Institut FKIE, Germany.
    Gaspers, Bastian
    Fraunhofer-Institut FKIE, Germany.
    Peräjärvi, Kari
    STUK-Radiation and Nuclear Safety Authority, Finland.
    Gårdestig, Magnus
    Linköpings universitet, Institutionen för medicin och hälsa. Linköpings universitet, Medicinska fakulteten.
    Possible scenarios for radiation measurementsand sampling using unmanned systems: ERNCIP thematic group Radiological and nuclear threatsto critical infrastructure Task 3 deliverable 22015Rapport (Annet vitenskapelig)
    Abstract [en]

    There is significant potential for the use of unmanned remote control vehicles in sampling andmeasuring radiological events. No attempt to standardise sampling and measurement methods usingthese types of vehicles has been made so far. Common standards would simplify the use of remotecontrol vehicles in an emergency scenario and would thus be very valuable in critical infrastructureprotection. The main advantage of using unmanned systems in radiological events is the protection ofthe involved human personnel.This document focuses on possible scenarios for remote control radiation measurements and samplingusing unmanned systems. We identified scenarios that can be separated in two categories. First, thereare prevention scenarios where unmanned systems can be used to prevent incidents involvingradioactive material and deterrence. Second, there are response scenarios where unmanned systemscan be used to gather information after incidents with radioactive material have occurred. We furthercondensed three main tasks (spatial mapping, search of sources and sampling) for unmanned systemsin the identified scenarios.In addition, this report summarises possible standards for unmanned systems. A very widelyrecognised standard collection of software frameworks for robot software development is the robotoperating system. Further important standards concerning communication with robots and control ofunmanned systems are battle management language, interoperability profile and joint architecture forunmanned systems.

  • 85.
    Shah, Ghafoor
    et al.
    Linköpings universitet, Institutionen för datavetenskap, ESLAB - Laboratoriet för inbyggda system.
    Arslan, Saad
    Linköpings universitet, Institutionen för datavetenskap, ESLAB - Laboratoriet för inbyggda system.
    Design of an in-field Embedded Test Controller2011Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Electronic systems installed in their operation environments often require regular testing. The nanometer transistor size in new IC design technologies makes the electronic systems more vulnerable to defects. Due to certain reasons like wear out or over heating and difficulty to access systems in remote areas, in-field testing is vital. For in-field testing, embedded test controllers are more effective in terms of maintenance cost than external testers. For in-field testing, fault coverage, high memory requirements, test application time, flexibility and diagnosis are the main challenges.

    In this thesis, an Embedded Test Controller (ETC) is designed and implemented which provides flexible in-field testing and diagnostic capability with high fault coverage. The ETC has relatively low memory requirements for storing deterministic test data as compared to storing complete test vectors. The test patterns used by the ETC are stored separately for each component of the device under test, in system memory. The test patterns for each component are concatenated during test application according to a flexible test command. To address test application time (which corresponds to down time of the system), two different versions of the ETC are designed and implemented. These versions provide a trade off between test application time and hardware overhead. Hence, a system integrator can select which version to use depending on the cost factors at hand. The ETC can make use of an embedded CPU in the Device Under Test (DUT), for performing test on the DUT. For DUTs where no embedded CPU is available, there is the additional cost of a test specific CPU for the ETC. To access the DUT during the test application, the IEEE 1149.1 (JTAG) interface is used. The ETC generates test result that provides information of failing ICs and patterns.

    The designed and implemented versions of the ETC are validated through experimentations. An FPGA platform is used for experimental validation of the ETC versions. A set of tools are developed for automating the experimental setup. Performance and hardware cost of the ETC versions are evaluated using the ITC'02 benchmarks.

  • 86.
    Solis Marcos, Ignacio
    et al.
    Statens väg- och transportforskningsinstitut, Trafikanttillstånd, TIL.
    Galvao-Carmona, Alejandro
    Universidad Loyola Andalucía, Universidad Autónoma de Chile.
    Kircher, Katja
    Statens väg- och transportforskningsinstitut, Trafikanttillstånd, TIL.
    Reduced Attention Allocation during Short Periods of Partially Automated Driving: An Event-Related Potentials Study2017Inngår i: Frontiers in Human Neuroscience, ISSN 1662-5161, E-ISSN 1662-5161, Vol. 11, artikkel-id 537Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Research on partially automated driving has revealed relevant problems with driving performance, particularly when drivers' intervention is required (e.g., take-over when automation fails). Mental fatigue has commonly been proposed to explain these effects after prolonged automated drives. However, performance problems have also been reported after just a few minutes of automated driving, indicating that other factors may also be involved. We hypothesize that, besides mental fatigue, an underload effect of partial automation may also affect driver attention.

    In this study, such potential effect was investigated during short periods of partially automated and manual driving and at different speeds. Subjective measures of mental demand and vigilance and performance to a secondary task (an auditory oddball task) were used to assess driver attention. Additionally, modulations of some specific attention-related event-related potentials (ERPs, N1 and P3 components) were investigated. The mental fatigue effects associated with the time on task were also evaluated by using the same measurements.

    Twenty participants drove in a fixed-base simulator while performing an auditory oddball task that elicited the ERPs. Six conditions were presented (5-6 min each) combining three speed levels (low, comfortable and high) and two automation levels (manual and partially automated). The results showed that, when driving partially automated, scores in subjective mental demand and P3 amplitudes were lower than in the manual conditions. Similarly, P3 amplitude and self-reported vigilance levels decreased with the time on task. Based on previous studies, these findings might reflect a reduction in drivers' attention resource allocation, presumably due to the underload effects of partial automation and to the mental fatigue associated with the time on task. Particularly, such underload effects on attention could explain the performance decrements after short periods of automated driving reported in other studies. However, further studies are needed to investigate this relationship in partial automation and in other automation levels.

  • 87.
    Soudris, Dimitrios
    et al.
    Natl Tech Univ Athens, Greece.
    Papadopoulos, Lazaros
    Natl Tech Univ Athens, Greece.
    Kessler, Christoph
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska fakulteten.
    Kehagias, Dionysios D.
    CERTH, Greece.
    Papadopoulos, Athanasios
    CERTH, Greece.
    Seferlis, Panos
    CERTH, Greece.
    Chatzigeorgiou, Alexander
    CERTH, Greece.
    Ampatzoglou, Apostolos
    CERTH, Greece.
    Thibault, Samuel
    Inria Bordeaux, France.
    Namyst, Raymond
    Inria Bordeaux, France.
    Pleiter, Dirk
    Forschungszentrum Julich, Germany.
    Gaydadjiev, Georgi
    Maxeler Technol Ltd, England.
    Becker, Tobias
    Maxeler Technol Ltd, England.
    Haefele, Matthieu
    Univ Paris Sud, France.
    EXA2PRO programming environment: Architecture and Applications2018Inngår i: 2018 INTERNATIONAL CONFERENCE ON EMBEDDED COMPUTER SYSTEMS: ARCHITECTURES, MODELING, AND SIMULATION (SAMOS XVIII), ASSOC COMPUTING MACHINERY , 2018, s. 202-209Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The EXA2PRO programming environment will integrate a set of tools and methodologies that will allow to systematically address many exascale computing challenges, including performance, performance portability, programmability, abstraction and reusability, fault tolerance and technical debt. The EXA2PRO tool-chain will enable the efficient deployment of applications in exascale computing systems, by integrating high-level software abstractions that offer performance portability and efficient exploitation of exascale systems heterogeneity, tools for efficient memory management, optimizations based on trade-offs between various metrics and fault-tolerance support. Hence, by addressing various aspects of productivity challenges, EXA2PRO is expected to have significant impact in the transition to exascale computing, as well as impact from the perspective of applications. The evaluation will be based on 4 applications from 4 different domains that will be deployed in JUELICH supercomputing center. The EXA2PRO will generate exploitable results in the form of a tool-chain that support diverse exascale heterogeneous supercomputing centers and concrete improvements in various exascale computing challenges.

  • 88.
    Staack, Ingo
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska fakulteten.
    Aircraft Systems Conceptual Design: An object-oriented approach from <element> to <aircraft>2016Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    Aircraft Conceptual Design (ACD) is facing new challenges on the way to enhanced fidelity level required of the nowadays complex system design. Namely the integration of models and simulations of different fidelity levels to enhance the analysis capability while maintaining a streamlined, transparent, and low cost working process is required.

    In this thesis, the use of object-oriented Knowledge-Based Engineering (KBE) methods to enable an early integration of simulation models within the ACD phase are presented. Careful investigations of modelling and simulation approaches of multi-domain systems are carried out before, and their use in the ACD phase is examined regarding the efficiency between spend effort and result in accuracy. Enabling the named topics, a central, parametric information model approach is presented. By the extended use of XML, XSD and XSLT, domain-specific models can be translated from this dataset, supporting a direct CAD and automated simulations integration.

    Modelling systems as graph networks is a simple approach for unified modelling within the conceptual design stage. Based on this theory, the similarity of different modelling approaches like Dependency Structure Matrix (DSM), MDDSM, or Channel-Agency Networks is shown. Using object-oriented programming, all these and more aspects such as e.g. Fault Tree Analysis (FTA) can be globally handled as one graph set.

    Based on the outcomes of the theoretical part, the development of a ACD framework is described. Backed by a central XML-based namespace, this framework integrates a complete CAD environment to ensure an appropriate environment for the geometric domain modelling. Furthermore, the use of KBE for automated simulation model integration is exemplified by a whole aircraft simulation including the hydraulic aircraft flight control system (FCS).

  • 89.
    Ståhl, Johan
    Linköpings universitet, Institutionen för systemteknik, Datorteknik. Linköpings universitet, Tekniska fakulteten.
    Kollisionsdetekteringssystem för autonom robot2015Independent thesis Basic level (degree of Bachelor), 10,5 poäng / 16 hpOppgave
    Abstract [sv]

    Examensarbetet har utförts på företaget Husqvarna AB vid avdelning Concept & Features electric products (EN-NEP). Uppdraget var att utvärdera en alternativ kollisionsmetod till deras robotgräsklippare. Metoden som utvärderats går ut på att detektera kollision med hjälp av samplad data från en accelerometer samt samplad strömnivå från de bägge drivhjulens motorer.

    Den metod som används för att detektera kollision på nuvarande robotar fungerar väl men kräver att robotens kaross och chassi rör sig ifrån varandra för att krock skall detekteras. För att kunna reducera antalet komponenter och priset på roboten är andra metoder intressanta att utvärdera för uppdragsgivaren.

    En algoritm har designats i simulationsmiljö som sedan testats på ”riktigt” genom implementation i en Raspberry Pi som kommunicerar med robotgräsklipparen. Om den implementerade algoritmen detekterat krock på den samplade datan skickas ett meddelande till roboten att utföra sitt inbyggda krockmönster.

    Resultatet som erhölls var ett fungerande system med stor potential. Med fortsatt arbete skulle metoden kunna bli en framtida ersättare alternativt ett komplement till nuvarande metod.

  • 90.
    Sun, Huibin
    et al.
    Key Laboratory of Contemporary Design and Integrated Manufacturing Technology, Ministry of Education, Northwestern Polytechnical University, Xian, China.
    Wang, Zhan
    Key Laboratory of Contemporary Design and Integrated Manufacturing Technology, Ministry of Education, Northwestern Polytechnical University, Xian, China.
    Zhang, Yingfeng
    Key Laboratory of Contemporary Design and Integrated Manufacturing Technology, Ministry of Education, Northwestern Polytechnical University, Xian, China.
    Chang, Zhiyong
    Key Laboratory of Contemporary Design and Integrated Manufacturing Technology, Ministry of Education, Northwestern Polytechnical University, Xian, China.
    Mo, Rong
    Key Laboratory of Contemporary Design and Integrated Manufacturing Technology, Ministry of Education, Northwestern Polytechnical University, Xian, China.
    Liu, Yang
    Department of Production, University of Vaasa, Vaasa, Finland.
    Evaluation method of product–service performance2012Inngår i: International journal of computer integrated manufacturing (Print), ISSN 0951-192X, E-ISSN 1362-3052, Vol. 25, nr 2, s. 150-157Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In order to analyse product–service performance (PSP) during product–service systems’ (PSSs) running time, a PSP evaluation method is proposed. Interrelationship between a PSS’s provider and accepter is defined as product–service relationship (PSR). Concepts of product–service network and product–service chain are put forward to describe interrelationship among PSRs from different perspectives. The concept of PSP is proposed to evaluate interrelationship among PSR. Detailed evaluation indexes are designed to measure the five factors of PSP, including time, quality, cost, stability and reliability. A case study is provided to test the validity and efficiency of the evaluation model of PSP. The analysis results show that the evaluation model can make good efforts in benefiting product–service platform’s running, monitoring and optimising.

  • 91.
    Tallhage, Jonas
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Construction of a Low-Noise Amplifier Chain With Programmable Gain and Offset2013Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    A low-noise, variable gain amplier chain was constructed for interfa-cing a sensor to an ADC. During the course of the work two dierent methods -switched-capacitor circuits and chopping circuits - for dealing with 1/f noise wereinvestigated during the course of the work. The resulting circuit did not quitemeet the performance required by the specication, some possible improvementsare suggested.

  • 92.
    Taxén, Lars
    et al.
    Linköpings universitet, Institutionen för datavetenskap. Linköpings universitet, Tekniska högskolan.
    Olow, Peter
    KnowIT.
    On the Integration of Project Planning, System Anatomy, and System Architecture2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, we propose to conceptualize projects as an integration of three views: the planning, the system anatomy, and the architectural ones. The system anatomy is the core in the Integration Driven Development approach, which has been successfully employed in a number of complex projects in the telecom industry. An illustration showing the integrated view is proposed as an instrument for managing the project. We discuss what effects on planning and risk management can be expected from applying this method, and analyze our results from a theoretical perspective called the Activity Domain Theory. Our findings are two: an amelioration of the Integration Driven Development approach with architectural aspects, and a positioning of the Activity Domain Theory with respect to the relevance versus rigor discourse in the project management discipline

  • 93.
    Taxén, Lars
    et al.
    Ericsson, Stockholm, Sweden .
    Östman, Fredrik
    Ericsson, Stockholm, Sweden .
    Hardware/Software Co-verification of a Telephone Exchange: A Case Study1995Inngår i: Codesign: computer aided software/hardware engineering / [ed] J. Rozenblit and K. Buchenrieder, Piscataway: IEEE Press, 1995, s. 414-424Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

     Large hardware/software systems can be modeled in C and VHDL and functionally completely verified early in the design process. This means that errors can be detected early and that continuous modeling and coverification can be done during the entire design process. The models will act as a contract between software and hardware design departments, and thus contribute to the quality of the design

  • 94.
    Thorarensen, Sebastian
    et al.
    Linköpings universitet, Institutionen för datavetenskap. Linköpings universitet, Tekniska fakulteten.
    Cuello, Rosandra
    Linköpings universitet, Institutionen för datavetenskap. Linköpings universitet, Tekniska fakulteten.
    Kessler, Christoph
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska fakulteten.
    Li, Lu
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska fakulteten.
    Barry, Brendan
    Movidius Ltd, Ireland.
    Efficient Execution of SkePU Skeleton Programs on the Low-power Multicore Processor Myriad22016Inngår i: 2016 24TH EUROMICRO INTERNATIONAL CONFERENCE ON PARALLEL, DISTRIBUTED, AND NETWORK-BASED PROCESSING (PDP), IEEE , 2016, s. 398-402Konferansepaper (Fagfellevurdert)
    Abstract [en]

    SkePU is a state-of-the-art skeleton programming library for high-level portable programming and efficient execution on heterogeneous parallel computer systems, with a publically available implementation for general-purpose multicore CPU and multi-GPU systems. This paper presents the design, implementation and evaluation of a new back-end of the SkePU skeleton programming library for the new low-power multicore processor Myriad2 by Movidius Ltd. This enables seamless code portability of SkePU applications across both HPC and embedded (Myriad2) parallel computing systems, with decent performance, on these architecturally very diverse types of execution platforms.

  • 95.
    Tideman, Erik
    Linköpings universitet, Institutionen för datavetenskap.
    Control System for Active Camouflage2015Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Implementation of a control system for an active camouflage system based on thermal elements and LED technology.

  • 96.
    Torggler, Manfred
    et al.
    Fernuniv, Germany.
    Keller, Joerg
    Fernuniv, Germany.
    Kessler, Christoph
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska fakulteten.
    Asymmetric Crown Scheduling2017Inngår i: 2017 25TH EUROMICRO INTERNATIONAL CONFERENCE ON PARALLEL, DISTRIBUTED AND NETWORK-BASED PROCESSING (PDP 2017), IEEE , 2017, s. 421-425Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Streaming applications are often used for embedded and high-performance multi and manycore processors. Achieving high throughput without wasting energy can be achieved by static scheduling of parallelizable tasks with frequency scaling. We present asymmetric crown scheduling, which improves on the static crown scheduling approach by allowing flexible split ratios when subdividing processor groups. We formulate the scheduler as an integer linear program and evaluate it with synthetic task sets. The results demonstrate that a small number of split ratios improves energy efficiency of crown schedules by up to 12% with slightly higher scheduling time.

  • 97.
    Tosteberg, Joakim
    et al.
    Linköpings universitet, Institutionen för systemteknik, Datorteknik. Linköpings universitet, Tekniska högskolan.
    Axelsson, Thomas
    Linköpings universitet, Institutionen för systemteknik, Datorteknik. Linköpings universitet, Tekniska högskolan.
    Development of a Wireless Video Transfer System for Remote Control of a Lightweight UAV2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    A team of developers from Epsilon AB has developed a lightweight remote controlledquadcopter named Crazyflie. The team wants to allow a pilot to navigate thequadcopter using video from an on-board camera as the only guidance. The masterthesis evaluates the feasibility of mounting a camera module on the quadcopter andstreaming images from the camera to a computer, using the existing quadcopterradio link. Using theoretical calculations and measurements, a set of requirementsthat must be fulfilled for such a system are identified. Using the requirementsas a basis, various camera products are investigated and the findings presented.A design to fulfill the requirements, using the found products, is proposed. Theproposed design is then implemented and evaluated.

    It is found that the Crazyflie system has the resources necessary to transferan image stream with the quality required for navigation. Furthermore, theimplementation is found to provide the required functionality. From the evaluationseveral key factors of the design that can be changed to further improve theperformance of an implementation are identified. Ideas for future work andimprovements are proposed and possible alternative approaches are presented.

  • 98.
    Turner, Anthony
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska fakulteten.
    The paper potentiostat2015Inngår i: 4th International Conference on Bio-Sensing Technology, 10-13 May 2015, Lisbon, Portugal., Elsevier, 2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This presentation will focus on meeting current challenges in decentralised diagnostics by using amperometric and votammetric systems printed on paper or plastic substrates to deliver inexpensive instruments for a wide range of electroanalytical applications. This approach combines the sophistication of advanced electrochemical biosensors with a simple manufacturing technique to create a use-and-throw instrument. The system is manufactured under ambient conditions. All interconnections are printed and an anisotropic conductive glue is used for interconnection between the chip and conductors. A screen-printed manganese dioxide battery and a vertical electrochromic display are incorporated in the instrument. The display is paper-like in the sense that it works in reflective mode, that is, no backlight is used to light up the pixels. This integrated biosensing platform forms a workhorse in our hands for a variety of diagnostic systems including enzyme electrodes for multi-parametric diabetes monitoring and for the management of chronic kidney disease, electrochemical sensors for enzymes such as G6-P or amylase (a marker for stress), label-free affinity sensors for cancer markers and heart disease, aptasensors for cancer cells, DNA Sensors and robust devices based on imprinted and smart polymers. Using these technologies, we envision over-the-counter paper instruments for self-diagnosis of common diseases such as diabetes, kidney disease and urinary tract infection; inexpensive devices for use by caregivers or paramedics such as the ”Stressometer” or heart attack indicators; home kits to support people after transplant surgery or cancer treatment, smart cartons for pharmaceuticals; pocket tests for allergens, food toxicity, drinking water etc. and strips or patches that communicate with mobile telecommunications. Realisation of these paradigm-changing new products requires the effective harnessing of emerging technology, inspired vision from clinical partners or others “users” and leading-edge engineering to design and produce functional systems in appropriate volumes at the right cost.

  • 99.
    Uebel, Karl
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska fakulteten.
    Conceptual Design of Complex Hydromechanical Transmissions2017Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    This thesis explores the conceptual design process of complex hydromechanical transmissions for mobile working machines. Efficient methods for design optimisation and controller development are presented to support the final concept selection.

    In the endeavour to develop new fuel-efficient driveline solutions for construction machines and off-road equipment new complex hydromechanical transmission concepts are being investigated. This pursuit is driven by stricter emission legislation, high fuel prices and a desire for a greener image both for customers and manufacturers. The trend towards more complex transmission architectures increases the need for more sophisticated product development methods. Complex multiple-mode transmissions are difficult to design and prototype and can be realised in a great number of architectures. By introducing a secondary energy storage in the machine the design space expands further for both hardware and software. There is accordingly a need for more reliable concept assessment in early design stages and the possibility to support concurrent engineering throughout the development process.

    Previous research on the design and development of hydromechanical transmissions has been limited to analysis of fixed concept designs or design optimization using very simple performance indicators. Existing methodologies for electrified on-road vehicles are not suitable for off-road working machines with hydromechanical transmissions and hydraulic energy storage.

    The proposed conceptual design process uses detailed quasi-static simulation models and targets to optimise the fuel efficiency of the specific machine specifications and operations. It is also shown how high-speed dynamic simulations can be used for controller development and hardware-in-the-loop simulations to support an efficient product design process. The methods are demonstrated for typical use cases targeting new transmission development for construction machines. Software control development is also treated using control optimisation and real-time simulation. Finally a novel hybrid hydromechanical motion system is presented for which an efficient design process is crucial to its end performance.

    Delarbeid
    1. Design Optimization of Complex Hydromechanical Transmissions
    Åpne denne publikasjonen i ny fane eller vindu >>Design Optimization of Complex Hydromechanical Transmissions
    2013 (engelsk)Inngår i: Journal of mechanical design (1990), ISSN 1050-0472, E-ISSN 1528-9001, Vol. 135, nr 9, s. 091005-1-091005-9Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Demands for higher fuel efficiency for off-highway applications motivate manufacturers to replace existing drive transmissions with more complex, high-efficiency transmissions. Increased intelligence and more advanced architectures are, however, more difficult to design and prototype. This leads to longer product development processes and a greater need for early product evaluation. The great variety of existing concepts also requires a methodology to support the choice of architecture. This paper proposes a design methodology for complex hydromechanical transmissions based on optimization. The main objective is to maximize energy efficiency and adapt the design to suit the typical operating behavior of the application. The methodology is also implemented on a multiple mode transmission concept sui for a heavy wheel loader application. It is shown that the design of the gearbox heavily influences the energy consumption and the necessity to use optimization when designing the gearbox.

    sted, utgiver, år, opplag, sider
    ASME Press, 2013
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-99379 (URN)10.1115/1.4024732 (DOI)000326172400006 ()
    Tilgjengelig fra: 2013-10-17 Laget: 2013-10-17 Sist oppdatert: 2017-12-06bibliografisk kontrollert
    2. Optimisation and Concept Sensitivity of Continuously Variable Hydromechanical Transmissions
    Åpne denne publikasjonen i ny fane eller vindu >>Optimisation and Concept Sensitivity of Continuously Variable Hydromechanical Transmissions
    2013 (engelsk)Konferansepaper, Oral presentation only (Annet vitenskapelig)
    Abstract [en]

    Demands for better fuel efficiency for mobile working machines motivate the manufacturers to replace existing drive transmissions with more complex, high-efficiency transmissions. Hydromechanical power-split transmissions can offer high energy efficiency throughout the speed range and allows a decoupling of the speed of the combustion engine and the vehicle speed. This paper deals with the design of complex hydromechanical power-split transmissions and suggests an optimisation-based design methodology to minimise the energy consumption and manufacturing cost of the gearbox. The methodology is applied to a multiple mode power-split transmission which is designed to suit the requirements and typical operating behaviour of a heavy wheel loader. It is shown how important the design of the transmission is to its characteristics and how manufacturing costs can be weighed against energy efficiency.

    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-99380 (URN)
    Konferanse
    8th International Conference on Fluid Power Trans- mission and Control, April 9-11, Hangzhou, China
    Tilgjengelig fra: 2013-10-17 Laget: 2013-10-17 Sist oppdatert: 2017-11-09bibliografisk kontrollert
    3. Modular Design of Hydromechanical Transmissions for Mobile Working Machines
    Åpne denne publikasjonen i ny fane eller vindu >>Modular Design of Hydromechanical Transmissions for Mobile Working Machines
    2013 (engelsk)Inngår i: Proceedings of the 13th Scandinavian International Conference on Fluid Power,(SICFP2013), June 3-5, 2013, Linköping, Sweden, Linköping: Linköping University Electronic Press, 2013, s. 113-119Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    This paper demonstrates an optimisation-based method to design modular gearboxes scalable for a range of applications. The design is adapted to the typical operating behaviours of the reference vehicles and considers the manufacturing costs of the gearboxes. Hydromechanical continuously variable transmissions (CVTs) are today strong candidates to replace drive line transmissions based on fuel-thirsty torque converters in many mobile working machines. The advantages include wide range of torque/speed ratios, high energy efficiency throughout the speed range and decoupling of the engine speed and the vehicle speed. Advanced multiple mode CVTs, however, are difficult to evaluate early in the product development process due to the complex architectures and the great variety of possible concepts. There is consequently an increased need for methods to design, compare and evaluate the transmission concepts. To decrease the development and manufacturing costs, there is also a need for scalable transmission concepts that can be used in several applications of different classes. The results show the proficiency of the methodology compared to a manual design process and that the energy efficiency of the transmissions are heavy coupled to the designs.

    sted, utgiver, år, opplag, sider
    Linköping: Linköping University Electronic Press, 2013
    Serie
    Linköping Electronic Conference Proceedings, ISSN 1650-3686, E-ISSN 1650-3740 ; 92
    Emneord
    Hydromechanical transmissions, Power-split, Design optimisation
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-99381 (URN)10.3384/ecp1392a12 (DOI)978-91-7519-572-8 (ISBN)
    Konferanse
    Proceedings of the 13th Scandinavian International Conference on Fluid Power, (SICFP2013), June 3-5, 2013, Linköping, Sweden
    Tilgjengelig fra: 2013-10-17 Laget: 2013-10-17 Sist oppdatert: 2019-01-24bibliografisk kontrollert
    4. Simulation Aided Design and Testing of Hydromechanical Transmissions
    Åpne denne publikasjonen i ny fane eller vindu >>Simulation Aided Design and Testing of Hydromechanical Transmissions
    2014 (engelsk)Inngår i: The 9th JFPS International Symposium on Fluid Power, Matsue, 2014, 2014Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    This paper demonstrates the use of high-speed simulation in transmission conceptual design and presents a transmission test bed for hardware-in-the-loop simulations of hydromechanical transmission concepts. Complex transmissions, such as multiple-mode hydromechanical transmissions and hydraulic hybrid transmissions, present new difficulties and costs in the development process. There is today a greater demand for more efficient product development and more work has shifted towards simulation. The Hopsan simulation package allows robust, high-speed simulations suitable for both offline and hardware-in-the-loop simulation. New simulation models for hydromechanical transmissions are developed and used to simulate a known two-mode transmission concept. The same concept is also tested in hardware-in-the-loop simulations in the proposed transmission test bed. Results show good agreement with the hardware tests and highlight the proficiency of the simulation tools.

    Emneord
    Hydromechanical Transmission, Hardware-in-the-loop, Hopsan
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-126561 (URN)4-931070-10-8 (ISBN)
    Konferanse
    the 9th JFPS International Symposium on Fluid Power in Matsue, Shimane Japan, on October 28-31, 2014
    Tilgjengelig fra: 2016-03-30 Laget: 2016-03-30 Sist oppdatert: 2018-03-21
    5. Mode Shifting in Hybrid Hydromechanical Transmissions
    Åpne denne publikasjonen i ny fane eller vindu >>Mode Shifting in Hybrid Hydromechanical Transmissions
    2015 (engelsk)Inngår i: ASME/BATH 2015 Symposium on Fluid Power and Motion Control, ASME Press, 2015, s. 13-Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    Demands for low cost sustainable solutions have increased the use of and interest in complex hydromechanical transmissions for heavy off-road vehicles. In transmissions with multiplemodes, an important condition is to maintain the tractive force during the mode shifting event. For hybrid hydromechanical transmissions, with a direct connection to a hydraulic accumulator, the impressed system pressure caused by the hydraulic accumulator has not yet been observed to interfere with this condition. In this paper, a black box model approach is used to modify the hydraulic system after obtaining knowledge regarding how it is affected by a mode shift. A comparative study is carried out where a full vehicle model of a mobile working machine is simulated with two different hydraulic systems. The results show that different system solutions imply different demands on the included components, and that the mode shifting event is not a negligible factor in heavy hydraulic hybrid vehicles.

    sted, utgiver, år, opplag, sider
    ASME Press, 2015
    Emneord
    Mode shifting, hydromechanical transmissions, fluid power, heavy construction machinery
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-126556 (URN)10.1115/FPMC2015-9583 (DOI)000373970500045 ()978-0-7918-5723-6 (ISBN)
    Konferanse
    ASME/BATH 2015 Symposium on Fluid Power and Motion Control, Chicago, Illinois, USA, October 12–14, 2015
    Prosjekter
    Research on Hydromechanical Transmissions and Hybrid Motion systems, RHYTHM
    Forskningsfinansiär
    Swedish Energy Agency, P39367-1
    Tilgjengelig fra: 2016-03-30 Laget: 2016-03-30 Sist oppdatert: 2019-08-21
    6. A novel hydromechanical hybrid motion system for construction machines
    Åpne denne publikasjonen i ny fane eller vindu >>A novel hydromechanical hybrid motion system for construction machines
    2017 (engelsk)Inngår i: International Journal of Fluid Power, ISSN 1439-9776, Vol. 18, nr 1, s. 17-28Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    This paper deals with a novel type of hybrid motion system for construction machines based on a common pressure rail shared between a hydromechanical power-split transmission and secondary controlled work hydraulics. A construction machine with driveline and work functions is a complex coupled motion system and the design of an effective hybrid system needs to take both subsystems into account. Studies on energy efficient hybrid systems for construction machines have hitherto principally focused on one subsystem at a time - work hydraulics or driveline. The paper demonstrates a use case with a specific transmission concept proposal for a medium-sized wheel loader. The system is modelled and simulated using an optimal energy management strategy based on dynamic programming. The results show the benefits of a throttle-free bidirectional link between the machine's subsystems and the energy storage, while taking advantage of the complex power flows of the power-split transmission.

    sted, utgiver, år, opplag, sider
    Abingdon, UK: Taylor & Francis, 2017
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-142329 (URN)10.1080/14399776.2016.1210423 (DOI)
    Tilgjengelig fra: 2017-10-26 Laget: 2017-10-26 Sist oppdatert: 2017-11-09bibliografisk kontrollert
  • 100.
    Unnikrishnan, Vishnu
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniska Kretsar och System. Linköpings universitet, Tekniska fakulteten.
    Vesterbacka, Mark
    Linköpings universitet, Institutionen för systemteknik, Elektroniska Kretsar och System. Linköpings universitet, Tekniska fakulteten.
    Mitigation of Sampling Errors in VCO-Based ADCs2017Inngår i: IEEE Transactions on Circuits and Systems Part 1: Regular Papers, ISSN 1549-8328, E-ISSN 1558-0806, Vol. 64, nr 7, s. 1730-1739Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Voltage-controlled-oscillator-based analog-to-digital converter (ADC) is a scaling-friendly architecture to build ADCs in fine-feature complimentary metal-oxide-semiconductor processes. Lending itself to an implementation with digital components, such a converter enables design automation with existing digital CAD hence reducing design and porting costs compared with a custom design flow. However, robust architectures and circuit techniques that reduce the dependence of performance on component accuracy are required to achieve good performance while designing converters with low accuracy components like standard cells in deeply-scaled processes. This paper investigates errors resulting from the sampling of a fast switching multi-phase ring oscillator output. A scheme employing ones-counters is proposed to encode the sampled ring oscillator code into a binary representation, which is resilient to a class of sampling induced errors modeled by the temporal reordering of the transitions in the ring. In addition to correcting errors caused by deterministic reordering, proposed encoding suppresses conversion errors in the presence of arbitrary reordering patterns that may result from automatic place-and-route in wire-delay dominated processes. The error suppression capability of the encoding is demonstrated using MATLAB simulation. The proposed encoder reduces the error caused by the random reordering of six subsequent bits in the sampled signal from 31 to 2 LSBs for a 31-stage oscillator.

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