Engineering of real-time systems with an experiment in hybrid control

Anders P. Ravn, Thomas Juul Eriksen, Michael Holdgaard, Hans Rischel

    Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review

    Abstract

    The core of this paper reports on development ofa multithreaded, multiprocessor program for an embedded system.It covers all phases of the development fromrequirements through successively refined designs with formal verification to implementation. The program controls an experimentalhydraulically powered manipulator with two links. The architecture uses local control for each of the links, and has a mode switched control algorithm which detects and reactson changes in model parameters due to variations in the forcesacting on the link. The result shows that it is feasible to check a design against realistic top level requirements with specific assumptions about th control and mode detection algorithms. The design is detailed to an architecture that isolate these and other algorithms suppliedby control engineers, thus providing a precise interface descriptionwith a potential for reuse. Specifications of requirements and designs are expressed in duration calculus,a real-time interval logic, which is also used in verification. Theimplementation is done in occam for a network of four transputer's.Low level timing constraints are checked manually by calculating path lengths.
    Original languageEnglish
    Title of host publicationEmbedded Systems
    Place of PublicationBerlin
    PublisherSpringer
    Publication date1998
    Pages316-352
    Publication statusPublished - 1998

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