Generation of functional mock-up units for co-simulation from simulink®, using explicit computational semantics: work in progress paper

As the complexity of Software-Intensive and Cyber-Physical Systems increases, multiple formalisms are used to model different parts of a system. Rather than building simulators for these combinations of multiple formalisms, co-simulation is often used to orchestrate multiple simulations. One emerging industry standard in this field is the Functional Mock-up Interface (FMI). This standard defines the interface implemented by Functional Mock-up Units (FMUs). An FMU is encoded as a zip-file containing model variable types and values in XML-format as well as the model's equations in C C-code. The C encoding allows one to distribute IP in binary form. Solvers are typically coded instead of explicitly modeled. However, this does not allow straightforward analysis or detection of for example algebraic loops and optimization possibilities. Explicitly modeling the solvers helps overcome these limitations, since this allows for the use of model-driven engineering techniques, such as model transformations. This paper presents a method to generate FMUs from Causal Block Diagram models, more specific Simulink® models, with explicitly modeled ODE solvers. The execution performance is compared between FMUs with explicitly modeled solvers and FMUs with coded solvers. We conclude that modeling the solver has a significant positive impact on the run-time efficiency of the generated FMUs.