Are quaternions and angular velocities in body-fixed frame?

Discussion in 'Simulation' started by Robert, May 20, 2020.

  1. Title pretty much says it all.

    If I have a model with a freejoint, which has some rotation around all axes, and I prescribe some angular velocity Ω on this joint, will this velocity be in inertial frame or body-fixed frame?

    So, looking at the image below, does angular velocity in the freejoint (1,0,0) spin around X_I or X_v?

    Last edited: May 25, 2020
  2. Nevermind, it's body-fixed. This was easily tested with a simulation of a floating body and setting an initial orientation and angular velocity.

    And body-fixed orientations and velocities is the only thing that makes sense for a developper.