FMU stands for Functional Mockup Unit and FMI for Functional Mockup Interface. The latter is an industry standard for simulation model runtime coupling, and basically defines an API and a meta data description file and directory structure for model exchange: see FMI-Standard webpage for details.
When you want an efficient FMU slave, there's probably no way around a native C/C++ implementation. However, implementing the C interface functions, the data handling, input/output variable handling and advanced features like saving and restoring the FMU state is not so simple and straight-forward.
However, the process of setting up the FMU (core files, modelDescription.xml
, directory structure) is pretty similar for most projects and can be automated with a configurable code generator - hence this project.
This is not a Software Development Library/Toolkit for accessing/supporting the FMI interface. Look at the FMU SDK if you need something like that.
Actually, the code generated by FMI Code Generator hides most of the messy FMI C function interface (including most of the memory management related to instantiating/deleting slave instances, and the state storage stuff) from the typical (engineering) user. Also, the generated code is pretty small, easy to read and comprehend and works cross-platform without any library setup issues.
See description of Test scenario: Stateless P-controller for a step-by-step tutorial.
Creating the barebone of an FMU should be as simple as that:
- clone this repository
- run the Python program
scripts/main.py
orscripts/FMIGeneratorWizard.py
- give the relevant information (model name, list of input and output vars, parameters, integration states etc.)
Once the generator has finished, you have a directory structure with fully working FMU source code (including build system files) with matching modelDescription.xml
that you can build cross-platform with the provided CMake-based build system.
The generated directory structure contains build system files for CMake and Qt-qmake. With CMake, you can easily generate makefiles for various compilers and development environments. With the pro-files you can directly start developing with Qt Creator (even though the FMU code itself is plain C/C++ code without Qt dependencies).
You can now start to implement your FMU-specific logic (physics, mathematical functions) by opening the <FmuModelName>.cpp
file within the <FmuModelName>/src/
subdirectory. The places where your own code is usually placed are marked with TODO comments.
Test-compile the source code using the provided build system files.
The template directory structure contains a deployment script/batch file (either <FmuModelName>/build/deploy.sh
or <FmuModelName>/build/deploy.bat
).
You may want to adjust the deploy.sh
script to add copying of own resource files, if needed.
Deployment works as follows (for Linux/Unix/Mac):
# change into generated directory structure
cd <FmuModelName>/build
# build the FMU in release mode
./build.sh release
# deploy the FMU, e.g. package the FMU in the zipped directory structure
./deploy.sh
The script runs with Python 2.7 and 3.x.
Simply install the python packages and pyqt5.
Ubuntu 16.04 - Python 2.7
> sudo apt get install cmake built-essential qt5-default qt5-qmake qtcreator python-pyqt5 pyqt5-dev-tools
The package pyqt5-dev-tools
contains the scripts pyuic5
and pyrcc5
needed for development of the FMIGenerator itself.
Ubuntu 16.04 - Python 3
> sudo apt get install cmake built-essential qt5-default qt5-qmake qtcreator python3 python3-pyqt5 pyqt5-dev-tools
Use homebrew and/or macports to install python and pyqt5 (or alternatively pip).
Things are bit more complicated for Windows. While the code can be compiled (thanks to the CMake build system) using quite a few build chains available on windows, the batch
-scripts are currently expecting a standard Visual Studio 2015 installation (c:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat
) and 7zip must be installed with 7za
in the PATH. Also, cmake
must be in in the PATH.
If your setup differs from that, edit the files build_VC_x64.bat
and deploy.bat
in directory data/FMI_template/build
.
The FMICodeGenerator is provided under a BSD 3-Clause License.
bin - batch/shell scripts to simplify/automate FMU generation
data - resources and template files
doc - documentation, also includes examples
examples - example directory structures (this is what the FMI generator should produce)
scripts - the actual python scripts
scripts/third_party - external library and scripts
third_party - external tools like the compliance checker