Modeling Methodology for Reconfigurable Distributed Systems using Transformations from GR-UML to GR-TNCES and IEC 61499

Abstract

As today's reconfigurable distributed control systems become more and more complex, the modelling of its controlling applications becomes more difficult. The Unified Modelling Language (UML) is considered as a standard language for modelling software and systems. However, UML does not provide formal semantics that allow correctness verification. It also has no semantics to design probabilistic scenarios running under energy and memory constraints. Moreover, despite its numerous assets when used to model Distributed Control Systems (DCS), UML still do not allow the simulation of models in some DCS hardware platforms. To overcome these limitations, we propose in this paper a new UML profile called GR-UML (Generalized Reconfigurable-UML) to model the mentioned features. Then, we introduce a modeling methodology that allows to use GR-UML, formal verification, and models deployment according to the IEC 61499 DCS standard. The paper presents also the rules responsible for automatic transformation of GR-UML to GR-TNCES (a Petri net formalism used for formal verification) and to function blocks (the elementary unit of the IEC 61499 standard). These transformations are implemented in a software tool. The contributions of the paper are proved using an example of microgrid control application example.