Dr. rer. nat.

Weiß, Gereon

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  • Publication
    Towards integrating undependable self-adaptive systems in safety-critical environments
    ( 2018)
    Weiß, Gereon
    ;
    Schleiß, Philipp
    ;
    Schneider, Daniel
    ;
    Trapp, Mario
    Modern cyber-physical systems (CPS) integrate more and more powerful computing power to master novel applications and adapt to changing situations. A striking example is the recent progression in the automotive market towards autonomous driving. Powerful artificial intelligent algorithms must be executed on high performant parallelized platforms. However, this cannot be employed in a safe way, as the platforms stemming from the consumer electronics (CE) world still lack required dependability and safety mechanisms. In this paper, we present a concept to integrate undependable self-adaptive subsystems into safety-critical environments. For this, we introduce self-adaptation envelopes which manage undependable system parts and integrate within a dependable system. We evaluate our approach by a comprehensive case study of autonomous driving. Thereby, we show that the potential failures of the AUTOSAR Adaptive platform as exemplary undependable system can be handled by our concept. In overall, we outline a way of integrating inherently undependable adaptive systems into safety-critical CPS.
  • Publication
    Generic management of availability in fail-operational automotive systems
    ( 2017)
    Schleiß, Philipp
    ;
    Drabek, Christian
    ;
    Weiß, Gereon
    ;
    Bauer, Bernhard
    The availability of functionality is a crucial aspect of mission- and safety-critical systems. This is for instance demonstrated by the pursuit to automate road transportation. Here, the driver is not obligated to be part of the control loop, thereby requiring the underlying system to remain operational even after a critical component failure. Advances in the field of mixed-criticality research have allowed to address this topic of fail-operational system behaviour more efficiently. For instance, general purpose computing platforms may relinquish the need for dedicated backup units, as their purpose can be redefined at runtime. Based on this, a deterministic and resource-efficient reconfiguration mechanism is developed, in order to address safety concerns with respect to availability in a generic manner. To find a configuration for this mechanism that can ensure all availability-related safety properties, a design-time method to automatically generate schedules for different modes of operations from declaratively defined requirements is established. To cope with the inherent computational complexity, heuristics are developed to effectively narrow the problem space. Subsequently, this method's applicability and scalability are respectively evaluated qualitatively within an automotive case study and quantitatively by means of a tool performance analysis.
  • Publication
    Adaptive Software für sicherheitskritische Funktionen in Batterie-elektrischen Fahrzeugen
    ( 2016)
    Rosenthal, Thorsten
    ;
    Feismann, Timo
    ;
    Schleiß, Philipp
    ;
    Weiß, Gereon
    ;
    Klein, Cornel
    Der Einzug von immer mehr Assistenz- und (teil-) autonomen Systemen in heutige und insbesondere in zukünftige Fahrzeuge verlangt höhere Sicherheitsanforderungen bis hin zu fehlertoleranten Systemen. Eine adaptive Software-Architektur für sicherheitskritische Funktionen hilft diese Fehlertoleranz in einem Fahrzeug robust, kostengünstig und auch energieeffizient umzusetzen. Diese Software bedient sich dabei der ohnehin vorhandenen Steuergeräte im Fahrzeug und ermöglicht dadurch eine Redundanz ohne die Einbringung von zusätzlichen Steuergeräten. Durch die Konformität zu AUTOSAR ist das Konzept universell auf jeder automotive-tauglichen Hardware realisierbar.
  • Publication
    Towards flexible and dependable E/E-architectures for future vehicles
    ( 2016)
    Weiß, Gereon
    ;
    Schleiß, Philipp
    ;
    Drabek, Christian
    Future vehicles are expected to evolve towards enabling fully electric and autonomous driving. However, technically this evolution requires fundamental changes of traditional automotive engineering principles. Specifically, challenges arise for the Electric/Electronic (E/E) vehicle architectures as underlying basis for almost all car functionalities. Higher demands on vehicle system's flexibility and dependability have to be incorporated. We present a novel approach for such future E/E-architectures which considers these requirements as first principles by exploiting runtime adaptation capabilities. Based on use cases, a generic hardware and software architecture is presented which enables technology-independent realization of the provided concepts. Additionally, the incorporated generic failure management and design support are introduced. The approach has been evaluated in different prototype demonstrators, including an e-vehicle prototype compromising enhanced driving functionality. Thereby, the advantages of the concepts for future vehicle E/E-architectural development could be highlighted.
  • Publication
    Adaptive Software-Architekturen für automatisierte Systeme
    ( 2016)
    Weiß, Gereon
    ;
    Schleiß, Philipp
    Die zunehmende Automatisierung von Systemen erfordert neue Ansätze zur Steigerung deren Verlässlichkeit und Flexibilität. In zukünftig hochautomatisierten Fahrzeugen kann der Fahrer die Kontrolle über das Fahrzeug vollständig abgeben und muss erst nach 10 Sekunden wieder übernehmen können. Hierfür müssen die hochautomatisierten Fahrfunktionen auch im Fehlerfall weiter funktionieren, d.h. fail-operational sein. Der Beitrag stellt ein neues Konzept und Lösung für zukünftige adaptive Fahrzeugsoftware-Architekturen vor. Dies ermöglicht kosteneffizient, die Ausfallsicherheit in eingebetteten, sicherheitskritischen Systemen zu realisieren. Es werden die grundsätzlichen Herausforderungen, neuen Mechanismen und die Integration in die heutige Entwicklung (u.a. mit AUTOSAR) dargestellt. Das Konzept wurde unter anderem in einem E-Fahrzeug implementiert und evaluiert.
  • Publication
    A safe generic adaptation mechanism for smart cars
    ( 2015)
    Ruiz, Alejandra
    ;
    Juez, Garazi
    ;
    Schleiß, Philipp
    ;
    Weiß, Gereon
    Today's vehicles are evolving towards smart cars, which will be able to drive autonomously and adapt to changing contexts. Incorporating self-adaptation in these cyber-physical systems (CPS) promises great benefits, like cheaper software based redundancy or optimised resource utilisation. As promising as these advantages are, a respective proportion of a vehicle's functionality poses as safety hazards when confronted with faultand failure situations. Consequently, a system's safety has to been sured with respect to the availability of multiple software applications, thus often resulting in redundant hardware resources, such as dedicated backup control units. To benefit from self-adaptation by means of creating efficient and safe systems, this work introduces a safety concept in form of a generic adaptation mechanism (GAM). In detail, this generic adaptation mechanism is introduced and analysed with respect to generally known and newly created safety hazards, in order to determine a minimal set of system properties and architectural limitations required to safely perform adaptation. Moreover, the approach is applied to the ICT architecture of a smart e-car, thereby highlighting the soundness, general applicability, and advantages of this safety concept and forming the foundation for the currently ongoing implementation of the GAM within a real prototype vehicle.