Recommended Time Limit of Forward Dynamics Simulation

[Stephanie Hachem]

Hello all,

In running forward dynamics simulations of the MoBL_ARMS human forearm model, I understand that simulations can become unstable after some time. I looked for forward dynamics examples provided in the OpenSim installation folder, and found that in toyLeg_example.cpp (attached), a very simple .osim model undergoes forward dynamics for 15 seconds (s). However, the MoBL_ARMS model is quite complicated, so I was wondering: might a person with experience in the conditions which cause a simulation to diverge/become unstable be able to provide some recommended upper limit of how long I should allow a simulation with that model to run? In particular, is 7 s fine? Is 15 s fine?

Thank you,

Stephanie

[Thomas Uchida]

how long I should allow a simulation with that model to run? In particular, is 7 s fine? Is 15 s fine?

Stability will depend on what the simulation is doing, not the amount of time it has run. Perhaps the model is operating beyond the range of motion for which it has been designed and validated?

[Stephanie Hachem]

Hi Mr. Uchida,

Thank you for the reply! I see, thank you for the information. I will keep that in mind.

Stephanie