The core features of Otfmi are:
load an FMU in an OpenTURNS object
set some initial values to ease initialisation
simulate the model, for a single set of input values or a sample
retrieve and store the simulation results.
About FMI, OpenTURNS and PyFMI¶
The functional mock-up interface (FMI) standard specifies a multipurpose interfaces to 0D/1D physical models. It is currently supported by many softwares, such as OpenModelica, Dymola, Amesim, Ansys, Simulink, etc.
The need for Otfmi¶
Using Python to easily perform computer experiments on 0D/1D models is seducing. Yet the tool chain, from the physical model to OpenTURNS, was incomplete. PyFMI objects, close to the FMUs methods, were to be adapted for an easier use with OpenTURNS’ methods.
Otfmi is developed by Phimeca, on the demand of EDF Prisme department, to meet this need of compatibility between PyFMI objects and OpenTURNS.
input, parameter, or input variable?
In the FMI standard (see table 18):
a FMU parameter remains constant during simulation (a single value).
a FMU input evolves during simulation (time-dependent values).
In OpenTURNS, the terms input and parameter are synonym and designate a variable in input of a probabilistic model. To reconcile the two worlds, we employ in Otfmi the terms of parameter and input in the sense of FMI. We call the input variables of a probabilistic model variables, or input variables.
FMI : ME or CS?
The FMI standard defines 2 kinds of FMUs : ModelExchange (ME) or CoSimulation (CS). The CoSimulation FMUs embed the numerical solver of their generation tool whereas the ModelExchange FMUs simulate with the solver of their host tool.
This package is licensed under the LGPL3.