Project: Jibo Dimensions - Meshes

Course Support URDF for Robot Modeling
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@staff I am doing the Jibo project from scratch. However I need their parts dimensions (base-waist-body-head) to start setting the inertias, geometry and collsions… I have accessed the site https://www.jibo.com/ and did not find the dimensions…I also tried to understand the meshes file, reading them, but I could not extract their dimensions from these files (there are a lot of values in “matrix” variable, but I don’t know what these values exactly means and if they have some relation with the dimensions)…
So what is the suggestion you can give me to find the dimensions of this robot?
I have watched the videos of it in site and instagram…and estimated the real values…for example. I assigned: 0,05 meters for the base - 0.07 meters for the waist - 0.12 meters for the body and 0,26 meter for the head [LENGTH). For radius I have used 0,15 - 0,16 - 0,17 - 0,20 meters respectivally. I assigne mass values as TOTAL = 12 kg…being for base and waist = 2 kg, for body = 3kg and for head = 5 kg. My doubt is…these values are near the reality…the Jimbo real size, however I have realized that the values used for the other robots (Gurdy, Mira, etc) are verly low…the mass value are 0.01 and the links height and radius also very low…0.05 or 0.008 for example…So I am confused…which is the scale the URDF uses? They use these measures in which unit (Kg/ meters/ grams/ centimeters/ inchs???) and the inertia calculator.py provided by the course is based on which measurement units?
Well…it is working…properly I think https://github.com/marcusvinicius178/marcus_ws/tree/master/jibo_robot_description%20(1)
now I need to execute the tasks…

Thanks in advance

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Hi,

So to create a robot simulation theer mainly two ways:

  1. Have all the physical data form the real robot and benchamrk it based on that.
  2. If ou dont have access to that, which is most of the times, you have to guess and iterate until the robot behaves as the real robot. The values in mira and gurdy are besed on what it works, not the real thing. Basically because Gurdy doesnt really resemble the robot that inspired it and mira there is no data abou it. So jibo is the same thing. Just place reasonable values of mas ( its in Kilograms) and calculate the inertias based on its basic geometry. There are other better methods but this is the fatsets and simplest.

In the future we might create an advanced course on robot creation tools.

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