Real-Time Systems

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Real-Time Systems – The term real time is one of the most misused terms in computer science and is commonly considered in various context, for example, real-time games, real-time video streaming, real-time communication. In fact, real-time systems are not characterized by being considerably fast but by their connection to the real world and its real time. The goal of real-time systems is to provide results of functions within deadlines. Depending on the point of view, real-time systems are usually embedded systems or cyber-physical systems, when emphasizing the aspect of controlling physical objects. The research field of real-time systems spans from system-software topics (such as real-time operating systems) to the resource analysis of real-time systems. Regarding the analysis of real-time systems, the research field addresses the determination of the worst-case execution-time bounds in order to meet timeliness.

Projects:

Watwa: Whole-System Optimality Analysis and Tailoring of Worst-Case–Constrained Applications

Energy-constrained real-time systems, such as implantable medical devices, are prevalent in modern life. These systems demand its software to fulfill both properties of safe and energy-efficient task executions. Regarding safety, these systems must execute their tasks within execution-time and energy bounds since resource-budget violations potentially cause danger to life. In order to guarantee the system's safe execution with the given time and energy resources, static program-code analysis tools…

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SPP 2378 ResPECT: Resilient Power-Constrained Embedded Communication Terminals

Within the wide subject of resilience in networked worlds ResPECT focuses on a core element of all networked systems: sensor- and actuator-nodes in cyber-physical systems. Communication up to today is understood and implemented as an auxiliary functionality of embedded systems. The system itself is disruption-tolerant and able to handle power failures or in a limited scope even hardware problems, but the communication isn't part of the overall design. In the best case it can make use of the underlying…

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maRE: Migration-Aware Multi-Core Real-Time Executive

This research proposal investigates the predictability of task migration in multi-core real-time systems. Therefore, we propose , a migration- aware real-time executive where migration decisions are no longer based on generic performance parameters but systematically deduced on application-specific knowledge of the real-time tasks. These so-called migration hints relate to temporal and spatial aspects of real-time tasks; they mark potential migration points in their non- sequential (multi-threaded)…

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ARTE: Softwareinfrastruktur betriebsmittelbeschränkter vernetzter Systeme (Phase 2)

Im Kontext der Gesamtvision der Forschergruppe BATS ist es das Ziel des Teilprojekts ARTE (adaptive run-time environment, TP 2) eine flexible Systemsoftwareunterstützung zu entwickeln. Diese soll es ermöglichen, für die Verhaltensbeobachtungen von Fledermäusen (TP 1) verteilte Datenstromanfragen (TP 3) auf einem heterogenen Sensornetzwerk (TP 4), bestehend aus stationären (TP 5) und mobilen (TP 7) Sensornetzwerkknoten, zu etablieren. Eine besondere Herausforderung stellen hierbei die knappen Ressourcen dar, im speziellen Speicher und Energie, sowie die wechselhafte Konnektivität der nur 2 g schweren mobilen Knoten. In Anbetracht dieser vielfältigen und teilweise konfligierenden Anforderungen soll ARTE in Form einer hochkonfigurierbaren Softwareproduktlinie realisiert werden. Ziel ist es, sowohl die unterschiedlichen funktionalen Anforderungen zwischen mobilen und stationären Knoten zu unterstützen, als auch wichtige nichtfunktionale Eigenschaften, wie niedriger Speicherverbrauch und Energieeffizienz. Entsprechend soll schon bei der Entwicklung von ARTE der Konfigurationsraum werkzeuggestützt und gezielt auf nichtfunktionale Eigenschaften untersucht werden, um gemäß der Anforderungen an das Projekt später im Einsatz eine optimierte Auswahl von Implementierungsartefakten zu bieten. Dabei ist explizit die dynamische Anpassbarkeit von Anwendungs- wie auch von Systemfunktionen zu berücksichtigen. Auf funktionaler Ebene wird ARTE Systemdienste in Gestalt einer Middleware bereitstellen, die Anpassung und Erweiterung zur Laufzeit unterstützt und auf Datenstromverarbeitung zugeschnitten ist, um eine ressourceneffiziente und flexible Ausführung von Datenstromanfragen zu ermöglichen.

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I4Copter: Platform for evaluation and education of embedded and safety-critical system software

The project originally started in the context of the CoSa project, where it is intended to be deployed as a creditable demonstrator for safety-critical mission scenarios. During the development of the I4Copter prototype, it turned out to be more of a challenge than initially expected, both in terms of complexity and applicability. The software required for flight control, navigation and communication is a comprehensive and demanding application for the underlying system software. That is why it…

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ARES: Adaptive Responsive Embedded Systems (ESI 2)

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AORTA: Aspect-Oriented Real-Time Architecture (Phase 1)

Das Projekt Real-Time Systems Compiler (RTSC) entwickelt einen Betriebssystem-gewahren übersetzer, welcher eine implementierungsagnostische Manipulation der Echtzeitsystemarchitektur von gegebenen Echtzeitanwendungen ermöglicht. Eine derartige Transformation der Architektur ermöglicht beispielsweise die überführung eines ereignisgesteuerten in ein zeitgesteuertes Echtzeitsystem. Letztere lassen sich beispielsweise wesentlich einfacher hinsichtlicher ihrer Sicherheit und Zuverlässigkeit verifizieren sind jedoch auch typischerweise mit signifikant höheren Entwicklungskosten verbunden. Die praktischen Vorteile einer automatsierten überführung mittels des RTSCs liegen entsprechend auf der Hand.

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AORTA: Aspect-Oriented Real-Time Architectures (Phase 2)

The goal of the AORTA project is to enhance the predictability of dynamic mixed-criticality real time systems by extracting critical paths. These paths are to be transformed into their static equivalents and to be executed in a time-triggered fashion at run-time. In comparison to event triggered processes, time-triggered execution tends to underuse resources. Therefore the optimistic execution model of mixed-criticality real-time systems will be retained. Only in case of an emergency the real-time…

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QRONOS: Quality-aware Co-Design of Responsive Real-Time Control Systems

A key design goal of safety-critical control systems is the verifiable compliance with a specific quality objective in the sense of the quality of control. Corresponding to these requirements, the underlying real- time operating system has to provide resources and a certain quality of service. However, the relationship between real-time performance and quality of control is nontrivial: First of all, execution load varies considerably with environmental situation and disturbance. Vice versa, the…

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LARN: Latency and Resilience-aware Networking

The poject develops transport channels for cyber-physical networks. Such channels need to be latency- and resilience-aware; i.e. the latency as seen by the application must be predictable and in certain limits, e.g. by balancing latency and resilience, be guaranteed. This is only possible by an innovative transport protocol stack and an appropriate fundament of operating system and low level networking support. Thereto the current proposal unites the disciplines Operating Systems / Real-Time Processing…

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e.LARN: Energy-, Latency- and Resilience-aware Networking

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