[ODE] robotic simulation

[Max Lungarella]

hi there,

thanks for replying.

> When I set out to write a robot simulator (see
> http://www.natew.com/juice),

i tried "juice", it's pretty cool, and well designed. the only problem that i
have with it, is that i cannot export the models i realize. in other words, it
would be neat if i could construct something using juice, and be able to
import this something in one of my own programs. do you have plans do add
similar feature?

> Using ODE, you can created bodies and joints and connect them arbitrarily
> and everything just works.  With Dynamechs, my understanding is that any
> closed loops need to be handled as special cases.  In retrospect, I think
> that would probably be almost trivial to deal with.  If you think of the
> structure as a graph, where bodies are nodes and joints are edges, you
> would just create the Dynamechs objects by traversing the graph, and when
> you find a cycle in the graph (easily detectable), you create one of
> Dynamechs' "secondary" joints.

yep. the only problem, that i have with this approach, is that almost the
whole body is some sort of special case - read "hack" - and therefore less
intuitive to design. i tried to use dynamechs and i still don't grasp it
completely. ode is so easy to use and also aesthetically more pleasant ;)

> How detailed do you want the simulation to be?

my plan is to simulate a humanoid robot with a reduced number of degrees of
freedom, let's say 10. the simulation would have to be fairly accurate, since
i'd like to develop the control architecture in software and use this very
architecture for the control of a real robot in a second time step. the
modeling of the motors does not worry me as much as the modeling of the ground
reaction forces, since the feet of my biped robot are not hard, but kind of
soft and deformable.

cheers,
    max


--
Max Lungarella
Neuroscience Research Institute
Tsukuba AIST Central 2
Umezono 1-1-1, Tsukuba 305-8568
Japan
Tel +81-298-615369
Fax +81-298-615841
http://www.lungarella.com/max/