Re: [simspark-devel] new problem of new server

[Jan M. <mu...@un...>]

Hi all,

Joschka Boedecker wrote:

>>> Could you please try to comment out the joint stops in the soccerbot.rsg
>>> file? I suspect them to have something to do with this problem.
>> Yes, it works after comment out the joint stops.
> 
> OK, thank you for the confirmation.

I made the following observation. I let the soccerbot try to do some 
squats, i.e. after the init command it only sent the fixed string
"(rle4 -0.5)(rle2_3 0.5 0)(lle4 -0.5)(lle2_3 0.5 0)". The movement 
*always* started with a little jump. Commenting out the (setHighStopDeg 
0 X) statements for rle4 and lle4 made this go away. Changing the 
allowed maxangle from 0 to 1 also made the jumping go away.  So the 
problem could be that the joints are already at a stop, when the 
movement starts.

>>> The joint stops were easy to implement, but I'm afraid that some ODE
>>> parameters might have to be adjusted to be able to use them in a stable
>>> way. If this is the case, I have to remove the joint stops again for
>>> now, since we don't have much time to find good parameters currently :-(
>> Well, doing is usually harder than thinking.
>> Maybe human referee can take this responsibility ;-)

This year the referees will probably have a lot of responsibilities, 
which usually means less volunteers.  :-(

> Yes, I think so, too. We'll have to have some kind of statement in the
> rules that forbids, e.g. using the feet as wheels, but it's difficult to
> formulate it to be "non-fuzzy".

I will add a section about using common sense to the rules, which states 
something like "even if this behavior does not violate the rules on the 
syntactic level, YOU and ME know it's wrong and therefore we are going 
to treat it as wrong".

> It seems certain, though, that we can not use joint stops reliably right
> now. I will comment out the joint stops for the final release.

:-(

Perhaps adding 1 degree to the max/min would be okay (see above).
Yuan could you test this?


Thanks,
Jan