FMU4cpp is a GitHub template repository that allows you to easily create cross-platform FMUs compatible with FMI 2.0 & FMI 3.0 for Co-simulation using CMake and C++.
The framework generates the required modelDescription.xml and further packages
the necessary content into a ready-to-use FMU archive.
- Clone this repository using the "Use this template" button.
- Browse the example models from the examples branch.
- Implement your own model by inheriting from the provided
fmu_baseabstract class. - Create an FMU target by using the provided
generate_fmuCMake function. - Build. Models for your platform are located in a
modelsfolder within the build folder. - Upload your changes to GitHub to trigger cross-compilation and validation against fmusim.
- Download cross-compiled FMUs from the Actions tab.
You can also use FMU4cpp as a CMake FetchContent dependency in a pre-existing CMake project.
include(FetchContent) FetchContent_Declare( fmu4cpp GIT_REPOSITORY https://github.com/Ecos-platform/fmu4cpp.git GIT_TAG git_tag_commit_or_branch_to_use ) FetchContent_MakeAvailable(fmu4cpp)
Then, you can create your own FMU by inheriting from fmu4cpp::fmu_base and using the generate_fmu function.
#include <fmu4cpp/fmu_base.hpp> using namespace fmu4cpp; class BouncingBall : public fmu_base { public: FMU4CPP_CTOR(BouncingBall) { register_real( "height", &height) .setCausality(causality_t::OUTPUT) .setVariability(variability_t::CONTINUOUS)) .setInitial(initial_t::EXACT); register_real( "velocity", &velocity) .setCausality(causality_t::LOCAL) .setVariability(variability_t::CONTINUOUS); register_real( "gravity", &gravity) .setCausality(causality_t::PARAMETER) .setVariability(variability_t::FIXED); register_real( "bounceFactor", &bounceFactor) .setCausality(causality_t::PARAMETER) .setVariability(variability_t::FIXED); BouncingBall::reset(); } bool do_step(double dt) override { // Update velocity with gravity velocity += gravity * dt; // Update height with current velocity height += velocity * dt; // Check for bounce if (height <= 0.0f) { height = 0.0f; // Reset height to ground level velocity = -velocity * bounceFactor;// Reverse velocity and apply bounce factor } return true; } void reset() override { height = 10; velocity = 0; gravity = -9.81f; bounceFactor = 0.6f; } private: double height{}; // Current height of the ball double velocity{}; // Current velocity of the ball double gravity{}; // Acceleration due to gravity double bounceFactor{};// Factor to reduce velocity on bounce }; model_info fmu4cpp::get_model_info() { model_info info; info.modelName = "BouncingBall"; info.description = "A bouncing ball model"; return info; } FMU4CPP_INSTANTIATE(BouncingBall);
Cross-compilation (64-bit linux/windows) occurs automatically when you push your changes to GitHub.
Such easy, such wow.
- C++17 compiler
- CMake >= 3.15