Too large values for explicit joint damping can cause models to fly apart

Issue #2554 new
Shane Loretz
created an issue

The <damping> tag applies a force depending on the velocity of the joint. If this value is too large the force will result in a new velocity that's greater than the previous timestep in the opposite direction, which oscillates until the model flies apart.

It would be nice if explicit damping would cap the force applied to the amount needed to stop joint movement, though I'm not sure how feasible getting that number is.

Comments (4)

  1. Tully Foote

    For a given damping force you can make the step size smaller and consequently the force will not saturate as quickly and cause the oscillation. But that only changes the range of problematic damping forces. And a smaller step size has significant performance implications and there will still be a critical damping force that will cause these oscillations.

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