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

[Joschka B. <jbo...@un...>]

Hi Yuan,

On Tue, 2007-06-19 at 15:52 +0800, Yuan Xu wrote:
> Hi Joschka,
> 
> Also about the joint angle restriction,
> it seems that when the joint angle is out of range, ODE will apply a
> force to restrict it,
> but the motor is still working, then resulting the joint angle
> concussion, at last the whole robot disjointed.

:-(

> After restricting the desired joint angle in our agent (i.e. the robot
> should not try to turn an angle out of the range),
> the simulation became stable.
> However, if a robot missing the restriction itself, the simulation may
> interrupted by it...
> I think we can set the motor velocity to zero while the joint is out of range.

This sounds reasonable (actually, I remember now that we implemented
something similar in our HOAP-2 robots to protect them ;-) ). This
should not be too hard to implement, since HingeEffector and
UniversalJointEffector both have a reference to their respective Joint
as a member variable. Using this, we can easily get all the information
like current joint angle, and joint stops :-) Would you like to try?

Thanks for all your efforts,
Joschka