Dr. rer. nat.

Weiß, Gereon

Filters

8 6
Reset filters

Settings
Now showing 1 - 10 of 14
  • Publication
    Planetares Zusammenspiel
    ( 2014)
    Zeller, Marc
    ;
    Weiß, Gereon
    Die zunehmende Anzahl an Funktionen in vernetzten eingebetteten Systemen erhöht auch die Komplexität der Software kontinuierlich. Die Modularisierung der Funktionen in einzelne Softwarekomponenten und standardisierte Softwarearchitekturen sollen dem entgegenwirken. Dabei ist es wichtig, die Softwareschnittstellen frühzeitig im Entwicklungsprozess zu definieren und abzusichern, um die Qualität und Fehlerfreiheit des Systems zu gewährleisten.
  • Publication
    Memory concepts for enabling adaptivity in distributed embedded systems
    ( 2014)
    Schleiß, Philipp
    ;
    Zeller, Marc
    ;
    Weiß, Gereon
    Establishing cost and resource efficient dependability through means of adaptivity in safety-critical distributed embedded systems is a strenuous endeavour, as the varying requirements on resilience, control and efficiency across domains prohibits a single solution to suit all needs. To assist the process of determining a safe and efficient system architecture with satisfactory precision, this work exemplifies the importance of differentiation by only addressing distributed embedded systems that perform multiple functions with alternating levels of criticality. Further, they do not require full fail-operational behaviour, thus allowing to sacrifice less important functions in the pursuit of preserving safety. Herein, a dynamic instantiation and graceful degradation strategy is developed to subsequently study its effect on cost when implemented in conjunction with execute-in-place (NOR-flash) or block-addressable (NAND-flash) memory concepts. Even though NOR-flash is generally considered to be a better candidate for such systems, this qualitative research produces evidence that NAND-flash memory concepts are likely to financially outperform traditional architectures when considering adaptivity.
  • Publication
    SafeAdapt - safe adaptive software for fully electric vehicles
    ( 2014)
    Schleiß, Philipp
    ;
    Zeller, Marc
    ;
    Weiß, Gereon
    ;
    Eilers, Dirk
    The promising advent of Fully Electric Vehicles (FEVs) also induces a shift towards fully electronic control of existing and new vehicle functions. Hereby, critical functions, such as Brake- and Steer-by-Wire, require sophisticated redundancy solutions to ensure safety. As a result, the overall electric/electronic (E/E) architecture of a vehicle is becoming even more complex and costly. To address the need for safety, reliability and cost efficiency in future FEVs, the development of a novel adaptive architecture to manage complexity through generic, adaptive, and system-wide fault handling is essential. Moreover, to enable this transition, design simplicity, cost efficiency, and energy consumption are especially important elements. Consequently, the SafeAdapt project seeks a holistic approach by comprising the methods, tools, and building blocks needed to design, develop and certify such safety-critical systems for the e-vehicle domain. In detail, a platform core encapsulating the basic adaptation mechanisms for relocating and updating functionalities is developed on basis of AUTOSAR. It serves as foundation for an interoperable and standardised solution for adaptation and fault handling in upcoming automotive networked control systems. In particular, emphasis is laid on functional safety with respect to the ISO26262 standard, wherefore an integrated approach ranging from tool chain support, reference architectures, modelling of system design and networking, up to early validation and verification is derived. To realistically validate these adaptation and redundancy concepts, an e-vehicle prototype with different and partly redundant applications is being developed. Moreover, the presented work outlines the motivation and challenges of future E/E architectures and contributes a technical strategy to overcome those hindrances.
  • Publication
    Towards runtime adaptation in AUTOSAR
    ( 2013)
    Zeller, Marc
    ;
    Prehofer, Christian
    ;
    Krefft, Daniel
    ;
    Weiß, Gereon
    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
    Verifying & validating non-functional properties of automotive software architectures in early design stages
    ( 2013)
    Stante, Alexander
    ;
    Kamphausen, Benjamin
    ;
    Zeller, Marc
    ;
    Weiß, Gereon
    An increasing number of functions in modern automobiles are software-based. A modern automotive architecture contains up to 100 electronic control units (ECU) that communicate with one another to ensure proper vehicle functionality. The requirements and the set of provided functionalities of automotive embedded systems are growing, the complexity of these systems is continuously increasing as well. Early verification of automotive software architectures is necessary to prevent failures and to save costs during the design. Considering solely functional properties of the software for networked embedded systems is insufficient to satisfy the quality requirements in the automotive domain. To produce robust software-based embedded systems in a cost-efficient way, an early verification of non-functional properties is inevitable. Based on a specific simulation framework, written in SystemC, the open tool-chain framework ERNEST provides flexible mechanisms to verify non-functional properties of component-based software systems in early design stages. ERNEST can be integrated easily into a model-based design flow and is based on the open-source development platform Eclipse. Thus, it states an extensible tool platform for verifying non-functional properties, which can easily be enhanced by various analysis techniques.
  • Publication
    Modellbasierte Absicherung von GENIVI-Schnittstellen
    ( 2013)
    Meyer, Daniel
    ;
    Drabek, Christian
    ;
    Weiß, Gereon
    ;
    Zeller, Marc
    Da in Multi-Vendor-Plattformen wie GENIVI einzelne Komponenten von unterschiedlichen Zulieferern stammen können, müssen die Schnittstellen bereits frühzeitig im Entwurfsprozess definiert und abgesichert werden. Dazu wird ein modellbasierter Ansatz vorgestellt, der eine Modellierung, Simulation und Überprüfung der Komponenten-Schnittstellen ermöglicht.
  • Publication
    Interface verification using executable reference models: An application in the automotive infotainment
    ( 2013)
    Drabek, Christian
    ;
    Pramsohler, Thomas
    ;
    Zeller, Marc
    ;
    Weiß, Gereon
    Modern in-vehicle infotainment systems comprise highly interactive software components. The verification of the interfaces of such components poses a major challenge for developers. In this work, we present an approach for model-based verification of distributed infotainment components. We define a layered reference model which specifies the interaction between two components at syntactical and behavioral level. The layers abstract from the used middleware so developers may focus on the components' actual interface behavior. Additionally, we define a model execution framework which enables the reuse of the reference model for verification of interface implementations. We demonstrate the applicability of the approach using an industrial case study. Our approach aims at reducing errors in the communication behavior and increasing the overall product quality.
  • Publication
    Towards runtime adaptation in AUTOSAR
    ( 2013)
    Zeller, Marc
    ;
    Prehofer, Christian
    ;
    Krefft, Daniel
    ;
    Weiß, Gereon
    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
    ERNEST - framework for the early verification and validation of networked embedded systems
    ( 2013)
    Kamphausen, Benjamin
    ;
    Stante, Alexander
    ;
    Zeller, Marc
    ;
    Weiß, Gereon
    Since the requirements and the set of provided functionalities of networked embedded systems are growing, the complexity of these systems is continuously increasing as well. Early verification of embedded systems is necessary to prevent failures and to save costs during the design. Considering solely functional properties of the software for networked embedded systems is insufficient to satisfy the quality requirements in most of their application domains. To produce robust software-based embedded systems in a cost-efficient way, an early verification of non-functional properties is inevitable. ERNEST is an open tool-chain framework to enable the early verification of component-based software in the area of networked embedded systems. Based on a specific simulation framework, written in SystemC, ERNEST provides flexible mechanisms to verify non-functional properties in early design stages. ERNEST can be integrated easily into a model-based design flow and is based on the open-source development platform Eclipse. Thus, it states an extensible tool platform for verifying non-functional properties, which can easily be enhanced by various analysis techniques. To analyze and verify a networked embedded system, the modeled hardware, software and communication behavior is simulated as accurate as needed. The results of these simulations can be used in third-party tools or re-integrated into the initial model. Thus, an iterative model-driven development exploiting early prototyping is possible.
  • Publication
    Modellbasierte Validierung von Infotainment-Funktionen im Auto
    ( 2012)
    Paulic, A.
    ;
    Zeller, Marc
    ;
    Weiß, Gereon
    ;
    Eilers, Dirk
    Bei der Kaufentscheidung für ein Auto werden Infotainment- und Multimedia-Anwendungen immer wichtiger. Die Netzwektechnologie Media Oriented Systems Transport (MOST) ist derzeit Standard für automobile Infotainment-Systeme und ermöglicht anspruchsvolles Infotainment im Auto. Die zunehmende Komplexität und Interaktion dieser Funktionen ist eine große Herausforderung bei der Entwicklung. Die Qualität der Systeme muss bei stetig zunehmender Funktionalität gewährleistet sein, zudem soll die Entwicklung immer günstiger werden. Hierzu wird modellbasierte Softwareentwicklung bereits erfolgreich eingesetzt. In dieser Arbeit haben wir neue Konzepte zur modellbasierten Validierung von Infotainment-Funktionen entwickelt und umgesetzt. Dabei wurden sog. Referenzmodelle als ausführbare Spezifikationen eingeführt und zur Validierung wiederverwendet.