Now showing 1 - 5 of 5
  • Publication
    Generic management of availability in fail-operational automotive systems
    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
    Verifying & validating non-functional properties of automotive software architectures in early design stages
    ( 2013)
    Stante, Alexander
    ;
    Kamphausen, Benjamin
    ;
    Zeller, Marc
    ;
    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
    Context modeling for dynamic configuration of automotive functions
    ( 2013) ;
    Grigoleit, Florian
    ;
    Struss, Peter
    Current vehicles are usually equipped with an abundance of advanced driver assistant systems. Only a limited number of them can really be active permanently. This motivates our goal of providing the car with the means necessary to dynamically adapt the set of active functions to its current requirements. In this paper, we present a generic context modeling approach suitable for dynamic configuration of automotive functions. The demonstration of the feasibility of the proposed solution and evaluation of its effectiveness was based on a simulated prototypical system configuration. The simulations yielded to a significant reduction in average function activity of an exemplary car system. Depending on the provided context parameters, a reduction of up to 24% was achieved.
  • Publication
    Interface verification using executable reference models: An application in the automotive infotainment
    ( 2013) ;
    Pramsohler, Thomas
    ;
    Zeller, Marc
    ;
    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
    A multi-layered control architecture for self-management in adaptive automotive systems
    ( 2009)
    Zeller, Marc
    ;
    ; ;
    Knorr, Rudi
    In this paper we discuss the need of a novel control architecture for managing the growing complexity in modern vehicles and outline a multi-layered approach for self-management in adaptive automotive systems. With this multi-layered control architecture it is possible to react in an adequate and quick way to changes in the supervised technical system. Especially for complex distributed real-time systems with various different requirements and system objectives, like vehicles, this approach provides the necessary degree of flexibility and dependability. In a first evaluation of this control architecture in a realistic automotive scenario we show the advantages of the multi-layered approach compared to a traditional central control architecture.