NAO Robot gravity effect

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motaz
Posts: 4
Joined: 13 Jun 2013, 05:50

NAO Robot gravity effect

Post by motaz »

Hi

I'm trying to control NAO robot using remote API calls.
In my simulation I'm trying to make a sitting pose under gravity effect, the problems occurs when I make the NAO sit on a cube shape followed by removing the cube shape from the scene. The NAO robot should fall under gravity effect, but actually I found it stuck in the sitting pose without falling.

you can see the problem's video demo using this link
http://www.youtube.com/watch?v=HqWMkURK ... re=mh_lolz


Willing to get suggestions
Last edited by motaz on 14 Jun 2013, 02:26, edited 1 time in total.

coppelia
Site Admin
Posts: 10339
Joined: 14 Dec 2012, 00:25

Re: NAO Robot gravity effect

Post by coppelia »

Hello,

Indeed, the first version of the NAO is quite approximate and should be improved for next release. It seems that the masses are not correctly located, or do not have the correct values. Here is the official document from Aldebaran.
As a quick guess, it seems that the position of the center of mass (COM) of the various elements is not exact. Try to invert the visible layers, then right-click in the view [popup --> view --> Visualize inertias]. It seems at least that the COM of the torso is located too high.

You can correct the position of the COM in the shapes dynamics dialog, the X, Y, Z items of (Position/orientation of inertia frame). Do not check Relative to World, since there is a bug in release 3.0.3

Cheers

motaz
Posts: 4
Joined: 13 Jun 2013, 05:50

Re: NAO Robot gravity effect

Post by motaz »

Appreciate your help
I will try to play with it

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