Reproducing Solo12 Inertia Parameters


I’m trying to reproduce the measurements for the inertia parameters of the Solo12 (link to Github) and seem to be getting different values using Solidworks.

Here’s a picture of the calculation for the body where I’m including the robot’s base and the four hip AA modules, but the values differ compared to the .pdf (mass is 0.93 kg vs 1.02 kg):

I’m not very experienced with Solidworks, so I might be doing something obviously wrong here!
In any case, what is the process that was used to generate the values on Github?

Thanks very much,

that’s true - you’re not doing anything wrong.
The cad assembly that is available on GitHub was used to design and 3d print the robot.

Later in the building process I measured the weight of all the subassemblies and corrected the discrepancies between the model and real parts in a separate cad model.

Especially the total weight of all the wires and connectors on the robot was unknown during the design process. So after wiring the robot I compared the weight data and determined that the combined weight of all the wires and connectors for our Solo12 robot is around 210g.

I accounted for that by adding a box with the additional weight to the base of the robot and calculated the inertia parameters in Solidworks.

The weight of the base with the hip aa modules is around 1,25kg when accounting for the weight of all the wires and connectors on the robot.

Best. Felix

Thanks very much Felix, that makes sense!