Hi Stefan, Look at ChExternalDynamics<https://api.projectchrono.org/classchrono_1_1_ch_external_dynamics.html>. I implemented that class precisely for this type of use. See demo_MBS_external_dynamics.cpp<https://github.com/projectchrono/chrono/blob/main/src/demos/mbs/demo_MBS_external_dynamics.cpp> for an example of using this mechanism to integrate the van der Pol ODE system. Currently, ChExternalDynamics only supports 1st order ODEs which you would specify by providing a class derived from ChExternalDynamics and implementing the necessary virtual methods (to provide the RHS, initial conditions, and optionally the Jacobian). In the near future, I intend to extend it to also support DAEs (index-3 to begin with).
The recent FMI module in Chrono also relies on this mechanism to importing a model exchange FMU (note that the FMI standard only supports model exchange FMUs with dynamics described by ODEs). See the fmi_modex<https://github.com/projectchrono/chrono/tree/main/src/demos/fmi/fmi_modex> demo for an illustration of building a model exchange FMU (also for the van der Pol problem) and integrating it within a Chrono system. Best, Radu From: [email protected] <[email protected]> On Behalf Of Stefan Oberpeilsteiner Sent: Tuesday, September 3, 2024 3:58 PM To: ProjectChrono <[email protected]> Subject: [chrono] Add ODE in project:chrono Hi, I am playing around with project:chrono and was wondering if there is a way to add ODEs (tyre modelling, hydraulic systems, etc) to project:chrono and solve them within the dynamics solver. Kind regards, Stefan -- You received this message because you are subscribed to the Google Groups "ProjectChrono" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]<mailto:[email protected]>. To view this discussion on the web visit https://groups.google.com/d/msgid/projectchrono/1a77eb60-77cb-426b-a71c-51c658f3fc4en%40googlegroups.com<https://urldefense.com/v3/__https:/groups.google.com/d/msgid/projectchrono/1a77eb60-77cb-426b-a71c-51c658f3fc4en*40googlegroups.com?utm_medium=email&utm_source=footer__;JQ!!Mak6IKo!OK9RasNpxrkqvsFikYuCJluoM8cvhPa7XZxDpgkTCP7b4zI71RF46Fyx5vNoe71YrVQT9rLm75pSQ3CFYFDs801RaQ$>. -- You received this message because you are subscribed to the Google Groups "ProjectChrono" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/projectchrono/CH3PPF46CDC218550DEAD64FCA38CFBEE54A7932%40CH3PPF46CDC2185.namprd06.prod.outlook.com.
