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Multibody closed loop initialization

Multibody closed loop initialization

Hi all,

I am trying to correctly initialize a stewart platform model. If I use the UPS analytical joint to model the legs, everything goes fine. When I replace the legs model with standard joints, i get the error of many possible postures. My understanding is that this should not occur as long as the model starting values are properly initialized.

I have done the following:
-Solved inverse kinematic analytically
-Each leg has the universal joint starting angle (guess value) set to the value needed to have the platform in its inital position
-Each leg has the lenght of prismatic joint set to the length needed to have the platform in its initial position
-Platform body start position has been fixed (I have to add manually the each keyword in the text view, because OMEdit does not work properly)

I have checked that the guess value are correct: if I do not close the legs loops, and create each leg alone with a dummy mass at the end, when I run the model and visualize it, the legs are in the correct positions/orientations.

So I would like to know how I should correctly initialize the full model.
Thanks in advance

Edited by: Emanuele83 - Dec-06-20 11:03:12
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