Inertia matrix seems wrong

[triccyx]

Not easy to understand but at least it seems to have too much null cells.
Is it a precision problem?

[triccyx]

Also if the CM of .urdf file is the same as the one in .mo file, inertia martix should be the same in both case

[traversaro]

@triccyx Can you check with the example provided in the readme: https://github.com/robotology-playground/sdf-modelica#example-usage ? In that case, the inertia values of 0.01 seem to be correctly converted from urdf to Modelica.

[triccyx]

URDF <inertia ixx="5.1392929e-06" ixy="4.4959551e-07" ixz="-2.2106268e-06" iyy="1.0381641e-05" iyz="3.5075043e-07" izz="9.5451504e-06"/> MODELICA TRANSLATED I_11 = 0.000005, I_22 = 0.000010, I_33 = 0.000010, I_21 = 0.000000, I_32 = 0.000000, I_31 = -0.000002) It is for sure a precision issue look at ixy and I_21 But I don't know if this is relevant to my problems

…

On Fri, 8 Jun 2018 at 18:06, Silvio Traversaro ***@***.***> wrote: @triccyx <https://github.com/triccyx> Can you check with the example provided in the readme: https://github.com/robotology-playground/sdf-modelica#example-usage ? In that case, the inertia values of 0.01 seem to be correctly converted from urdf to Modelica. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#9 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AIsv-2MczdQaPSmGr2bMuvs_a06chgzOks5t6qCRgaJpZM4Ugiz_> .

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[traversaro]

Good catch. I think the problem is in numbers expressed with the scientific notation, however the error is minimal, so if you had strange results I do not think this is the problem.
I will be working on it.

[triccyx]

Same problem in CM vector position from frame_a in Modelica.Mechanics.MultiBody.Parts.Body

[traversaro]

Removing my assignment, if anyone wants to work feel free to do so.