Varying inertial properties but constant kinematics

[MaximilianDio]

Hi there.

I would like to optimize dynamic properties like mass, center of gravity, inertia etc., however, the kinematics and therefore the joint frames do not change. Is there a way to update the model inertial properties without building the complete model, running kinematics etc.

kind regards
Max

[jcarpent]

You can change the inertia property of the model manually.
For instance, model.inerias[joint_id].mass = 2. will set the Inertia quantity supported by joint_id to the value 2.

[MaximilianDio]

Ok that is helpful but also the center of mass?

Lets say I have a joint, and a mass is attached to it at an offset of r = [rx,ry,rz] in the joints coordinate frame, I could adjust the inertia matrix using Huygen-Steiner but I would still need to change the COM

[MaximilianDio]

Ah ok I see I can alter all the quantities that is perfect!

[jcarpent]

Yes, every quantity can be changed.