Rotational Inertia Calculation

masterscience91 — Mon, 12 Jul 2021 22:55:18 GMT

I have a robot assembly, which uses multiple rotary actuators in series. For these actuators, I need to calculate rotational Inertia(or mass moment of inertia) sequentially about multiple axes.

While calculating innertias moving sets subassemblies to align with the main assembly's origin (and sometimes suppressing multiple other subassemblies) in order to calculate is inertia becomes tedious when scaled up to larger robot assemblies.

In the picture below, you can see the highlighted 'assembly origin axes'(forming a small 3d cross) in the browser along with the rotary actuator axes (in series). I want to be able to calculate the torque required to drive the assembly for each of the rotary actuators, hence I need the rotary inertia of the attached components about the actuator's rotational axis(Kg*m^2).

Is there a way to sequentially select parts and calculate the rotational inertia of the selected parts with respect to a selected axis?

For example, I want to calculate the rotational Inertia of the (Leg_Adpater+Hip_Yaw+Thigh) about Axis_2 and the rotational Inertia of (Hip_Yaw+Thigh) about Axis_1 within the same assembly.

Is there an feature/plugin for this?

Best Regards,

RKJ

Re: Rotational Inertia Calculation

johnsonshiue — Tue, 13 Jul 2021 23:01:26 GMT

Hi! I am not aware of a tool or a workflow in Inventor evaluating mass prop for selected components. But, I think Fusion 360 does allow that. Please feel free to try it there.

Many thanks!

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Rotational Inertia Calculation

Re: Rotational Inertia Calculation