Now showing 1 - 4 of 4
  • Publication
    Verification of network end-to-end latencies for adaptive ethernet-based cyber-physical systems
    ( 2018)
    Manderscheid, Martin
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    Knorr, Rudi
    As Cyber-Physical Systems (CPS) are evolving towards flexible and smart systems, their dependable communication becomes a decisive factor. In order to still guarantee a predictive and real-time behavior, verifying the network performance of such adaptive systems is vital. Therefore, the performance-verification has to consider the runtime variability while scaling for larger number of applications and networks in CPS. We introduce a novel performance-verification approach with integrated variability enabling the analysis of adaptive Ethernet-based CPS. It incorporates a formal model capturing all relevant characteristics for deriving safe communication bounds. Its soundness has been evaluated in an extensive automotive case study and several changing test setups targeting scalability. The results show that this integrated variability approach is superior to a common static analysis and previously utilized heuristic. In direct comparison it outperforms static analysis by up to 95 percent within the evaluated automotive system. Moreover, the results show that it scales well and provides a profound basis for analyzing larger adaptive networked systems.
  • Publication
    Pattern-based approach for designing fail-operational safety-critical embedded systems
    ( 2015)
    Penha, Dulcineia
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    Stante, Alexander
    To deal with fail-operational (FO) requirements intoday's safety-critical networked embedded systems (SCNES), engineers have to resort to concepts such as redundancy, monitoring, and special shutdown procedures. Hardware-based redundancy approaches are not applicable to many embedded systems domains (e.g., automotive systems), because of prohibitive costs. In this scenario, adaptability concepts can be used to fulfill these FO requirements while enabling optimized resource utilization. However, the applicability of such concepts highly depends on the support for the engineering during system development. We propose an approach to cope with the challenges of fail-operational behavior of SCNES in which engineers are supported by design concepts for realizing safety, reliability, and adaptability requirements through the use of architectural patterns. The approach allows expressing FO concepts at the software architecture level. This lowers the effort for developing SCNES by utilizing generic patterns for genera land reoccurring mechanisms.
  • Publication
    Towards runtime adaptation in AUTOSAR
    ( 2013)
    Zeller, Marc
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    Prehofer, Christian
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    Krefft, Daniel
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    In many industrial application domains networked embedded systems realize safety-critical applications. In such systems, adapting the software distribution at runtime can be used to optimize system configurations, to add new features or to handle failure cases. The main objective of this paper is to devise a flexible and efficient solution for runtime adaptation in AUTOSAR, which requires minimal changes to the current architecture. We elaborate the main challenges for extending AUTOSAR and argue that small changes in the architecture and design process are feasible and effective for this purpose. Our work is validated by a proof of concept implementation.
  • Publication
    Towards runtime adaptation in AUTOSAR
    ( 2013)
    Zeller, Marc
    ;
    Prehofer, Christian
    ;
    Krefft, Daniel
    ;
    In many industrial application domains networked embedded systems realize safety-critical applications. In such systems, adapting the software distribution at runtime can be used to optimize system configurations, to add new features or to handle failure cases. The main objective of this paper is to devise a flexible and efficient solution for runtime adaptation in AUTOSAR, which requires minimal changes to the current architecture. We elaborate the main challenges for extending AUTOSAR and argue that small changes in the architecture and design process are feasible and effective for this purpose. Our work is validated by a proof of concept implementation.