ecos-platform / ecos

A simple, fast and easy to use co-simulation engine

Ecos

Ecos is a co-simulation engine.

Ecos (Easy co-simulation) is a fast, efficient and very easy to use co-simulation engine written in modern C++.

Ecos provides the following features:

• FMI for Co-simulation version 1.0 & 2.0
• SSP version 1.0
• Optional sandboxed/remote model execution
• Post-simulation plotting using matplotlib
• Command-line-interface (CLI)
• Simplified Python and C interface

Building

Ecos relies on vcpkg to handle dependencies.

Once installed, please add the entry VCPKG_ROOT to PATH pointing your /vcpkg folder. Alternatively, call CMake with -DCMAKE_TOOLCHAIN_FILE=[path to vcpkg]/scripts/buildsystems/vcpkg.cmake.

Example:

//windows
cmake . -A x64 -B build -DCMAKE_TOOLCHAIN_FILE="C:/vcpkg/scripts/buildsystems/vcpkg.cmake" -DECOS_BUILD_EXAMPLES=ON -DECOS_BUILD_TESTS=ON -DCMAKE_BUILD_TYPE=Release
cmake --build build --config Release

//linux
cmake . -B build -DCMAKE_TOOLCHAIN_FILE="/home/user/vcpkg/scripts/buildsystems/vcpkg.cmake" -DECOS_BUILD_EXAMPLES=ON -DECOS_BUILD_TESTS=ON -DCMAKE_BUILD_TYPE=Release
cmake --build build

Notes on static linking and vcpkg (windows)

In order to produce executables with no DLL dependencies on windows, you need to call CMake with -DVCPKG_TARGET_TRIPLET=x64-windows-static-md

Example

using namespace ecos;

int main() {
    
    simulation_structure ss;

    // add models
    ss.add_model("chassis", "chassis.fmu");
    ss.add_model("ground", "ground.fmu");
    ss.add_model("wheel", "wheel.fmu");
    
    //make connections
    ss.make_connection<double>("chassis::p.e", "wheel.p1::e");
    ss.make_connection<double>("wheel::p1.f", "chassis.p::f");
    ss.make_connection<double>("wheel::p.e", "ground.p::e");
    ss.make_connection<double>("ground::p.f", "wheel.p::f");
    
    // setup initialValues
    std::map<variable_identifier, scalar_value> map;
    map["chassis::C.mChassis"] = 4000.0;
    ss.add_parameter_set("initialValues", map);
    
    auto sim = ss.load(std::make_unique<fixed_step_algorithm>(1.0 / 100), "initialValues");
    
    sim->init();
    sim->step_until(10);
    
    sim->terminate();
}

SSP example

using namespace ecos;

int main() {
    
    auto ss = load_ssp("quarter-truck.ssp");

    // use a fixed-step algorithm and apply parameterset from SSP file
    auto sim = ss->load(std::make_unique<fixed_step_algorithm>(1.0 / 100), "initialValues");
    
    // setup csv logging
    csv_config config;
    config.register_variable("chassis::zChassis"); // logs a single variable
    
    auto csvWriter = std::make_unique<csv_writer>("data.csv", config);
    csvWriter->enable_plotting("ChartConfig.xml"); // enable post-simulation plotting
    sim->add_listener(std::move(csvWriter));
    
    sim->init();
    sim->step_until(10);
    
    sim->terminate();
}

Command line interface

Options:
  -h [ --help ]                 Print this help message and quits.
  -v [ --version ]              Print program version.
  -i [ --interactive ]          Make execution interactive.
  -l [ --logLevel ] arg (=info) Specify log level [trace,debug,info,warn,err,of
                                f].
  --path arg                    Location of the fmu/ssp to simulate.
  --stopTime arg (=1)           Simulation end.
  --startTime arg (=0)          Simulation start.
  --stepSize arg                Simulation stepSize.
  --rtf arg (=-1)               Target real time factor (non-positive number ->
                                inf).
  --noLog                       Disable CSV logging.
  --noParallel                  Run single-threaded.
  --logConfig arg               Path to logging configuration.
  --chartConfig arg             Path to chart configuration.
  --scenarioConfig arg          Path to scenario configuration.

Python interface

To use the python interface, simply clone the project and run:

pip install ./ecospy

See here for an example.

Note: if using an old pip version, append --use-feature=in-tree-build if you get an error about ../version.txt

---

Compile-time requirements

• Windows (10 >=) or Ubuntu (20.04 >=)
• C++17 compiler (MSVC >= 16 || gcc9 >=)
• CMake >= 3.17
• Vcpkg

Additional Linux requirements

sudo apt install libtbb-dev

Run-time requirements

• Python3 (required for plotting)
  • matplotlib
  • pandas

---

Want to build FMUs in C++? Check out FMU4cpp
Want to build FMUs in Kotlin/Java? Check out FMU4j
Want to build FMUs in Python? Check out PythonFMU
SSP generation made easy? Check out SSPgen

ecos's Issues

Get listed on the FMI tools page

We would like to encourage you to get your tool listed on the FMI tools page https://fmi-standard.org/tools/, see https://github.com/modelica/fmi-standard.org/blob/main/CONTRIBUTING.md#updating-the-tools-list for more information

Docker request and more example for Command line interface

Hi,
Do you have any docker version of ecos, it will be really helpful, since I have some issues to setup it,

Moreover, I have not found any example of Command line interface, could you please provide more,
Regards
T