Conference article

A Library for Synchronous Control Systems in Modelica

Martin Otter
DLR Institute of System Dynamics and Control, Wessling, Germany

Bernhard Thiele
DLR Institute of System Dynamics and Control, Wessling, Germany

Hilding Elmqvist
Dassault Systèmes AB, Ideon Science Park, Lund, Sweden

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Published in: Proceedings of the 9th International MODELICA Conference; September 3-5; 2012; Munich; Germany

Linköping Electronic Conference Proceedings 76:2, p. 27-36

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Published: 2012-11-19

ISBN: 978-91-7519-826-2

ISSN: 1650-3686 (print), 1650-3740 (online)


Based on the synchronous language elements introduced in Modelica 3.3; a library is described to utilize the new features in a convenient way for graphical model definition of sampled data systems. The library has elements to define periodic; non-periodic and event clocks that trigger elements to sample; sub-sample or super-sample partitions synchronously. Optionally; quantization effects; computational delay or noise can be simulated. Continuous-time equations can be automatically discretized and utilized in a sampled data system. This is demonstrated by utilizing the inverse of a nonlinear plant model in the feed forward path of a discrete controller of a mixing unit.


Synchronous models; sampled data systems; periodic systems; inverse systems


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