Semantic adaptation for FMI co-simulation with hierarchical simulators

Abstract

Model-based design can shorten the development time of complex systems by the use of simulation techniques. However, it can be hard to simulate the system as a whole if it is developed in a concurrent fashion by multiple and specialized teams. Co-simulation, with the support of the Functional Mockup Interface (FMI) Standard, is proposed as a way to promote tool interoperability while protecting the intellectual property of subsystems. The standard allows uniform communication between subsystem simulators, but does not state how the inputs and outputs should be interpreted, nor how the subsystems should interact correctly. Semantic adaptations can be quickly made to correct the interactions with subsystem simulators that were produced with different assumptions, and avoid changing those subsystems, their simulators, or the orchestration algorithm that computes the co-simulation. In this work, we explore how to describe common adaptations and what their meaning is in the context of FMI co-simulation. The result is a sound language that enables the implementation of adaptations with minimal effort. A distinct feature is that it describes adaptations for groups of interconnected subsystem simulators in the same way as for a single simulator, and the implementation is itself a simulator, thanks to a sound definition of hierarchical co-simulation. This work paves the way for research into the correct combination and interfacing of different adaptations.

Reconciling interoperability with efficient Verification and Validation within open source simulation environments

“…The Functional Mock-up Interface (FMI) is a widely used standard for model-based design and analysis of Cyber-Physical Systems (CPSs). In the literature we find many examples in different fields (see, e.g., [46,47,48,49]). Both Co-Simulation (CS) and Model Exchange (ME) paradigms are crucial to handle large-scale systems (see, e.g., [50,51]).…”

Seismic Hybrid Testing using FMI-based Co-Simulation

“…Coupling -Denotes the strategy that the orchestrator uses, in order to ensure that physical laws are respected. While it is common to mix the Orchestrator and Coupling together as one concept, as we will show later, the distinction is useful because the Orchestrator is generic and can be applied to many different simulation scenarios (e.g., consider the Jacobi and Gauss-Seidel schemes (Kübler and Schiehlen 2000; Bastian et al 2011)), but the Coupling is often specifically designed for a particular simulation scenario (e.g., the coupling can be implemented as a semantic adaptation (Gomes, Meyers et al 2018), or automatically generated from hints (Gomes, Oakes et al 2019;Oakes et al 2021)).…”

A Model based Toolchain for the Cosimulation of Cyber-physical Systems with FMI

“…This can lead to many revisions and iterations on the models while trying to interoperate them with the other models, and potentially generate a lot of input/output ports to cover all possible scenarios. Adaptation approaches (Gomes et al, 2018a) allow the reuse of existing models or FMUs by wrapping them in a simulation unit adapted to a particular cosimulation.…”