FMI 2.0 export

daedalus fmu exports a model as a Functional Mock-up Unit for FMI 2.0, so it runs in any FMI importer: Simulink, Dymola, OpenModelica, FMPy, Silver, or your own co-simulation master. One FMU carries both interfaces:

• Co-Simulation. The FMU steps itself with the model's own BDF or Dopri5 solver and event handling, inside fmi2DoStep.
• Model Exchange. The importer integrates; the FMU exposes the states, their derivatives and one event indicator per relation.

#Exporting

cargo build --release -p daedalus-cli -p daedalus-fmi
./target/release/daedalus fmu library/Daedalus -m Daedalus.Examples.TorqueConverter.StallTest -o StallTest.fmu

FMU Daedalus_Examples_TorqueConverter_StallTest: 552 variables, 2 states, 2 event indicators, 0 inputs, 0 outputs
wrote StallTest.fmu

The archive holds:

The runtime is the same library for every model; only model.bin changes. daedalus fmu finds it next to the daedalus executable, or through --fmi-lib or DAEDALUS_FMI_LIB. The release archives ship it next to the CLI.

#Validated with FMPy

CI exports StallTest.fmu on every pull request, validates modelDescription.xml with FMPy, runs the FMU both as Co-Simulation and as Model Exchange (with FMPy's CVode), and compares both runs with daedalus simulate:

./target/release/daedalus simulate library/Daedalus -m Daedalus.Examples.TorqueConverter.StallTest \
    -o ref.csv --vars rpm_engine,rpm_stall_theory
python3 tools/fmu_check.py StallTest.fmu ref.csv rpm_engine,rpm_stall_theory

fmpy validate StallTest.fmu: no problems found
CS: 1001 rows to t = 4.0
  CS  rpm_engine: max deviation 4.97e-06 of its range (final 2160.538718 vs 2160.538639)
  CS  rpm_stall_theory: max deviation 8.78e-07 of its range (final 2160.538718 vs 2160.538705)
ME: 1001 rows to t = 4.0
  ME  rpm_engine: max deviation 3.28e-06 of its range (final 2160.538718 vs 2160.538639)
  ME  rpm_stall_theory: max deviation 8.90e-07 of its range (final 2160.538718 vs 2160.538705)
OK

#Using the FMU from Python

from fmpy import simulate_fmu

res = simulate_fmu("StallTest.fmu", fmi_type="CoSimulation",
                   stop_time=4, output=["rpm_engine"])
print(res["rpm_engine"][-1])   # 2160.5

Parameters are set the usual way, with start_values={"engine.J": 0.3}.

#Limits

• The binaries are built for linux64; Windows and macOS FMUs need daedalus-fmi built on those platforms.
• FMU state get/set (fmi2GetFMUstate) and directional derivatives are not provided yet.
• In Model Exchange, a jump in a time table without an event can stall an importer's integrator; time events for table breakpoints are planned.

FMI 3.0 and FMU import are on the Roadmap.