[ODE] SOS - urgent help needed

[Neelam C]

Hi,

I am working on similar problem (dog). 

> 1. The dog perfektly stand on the ground, but as soon as it falls , it sinks 
> into the bottom half.
> Maybe some code extracts can help.
> nearCallBall does the following with each contact point:
>  contact[i].surface.mode = dContactSlip1 | dContactSlip2 | dContactSoftERP | 
> dContactSoftCFM | dContactApprox1;
>  contact[i].surface.mu = dInfinity;
>  contact[i].surface.mu2 = dInfinity;
>  contact[i].surface.slip1 = 0.4;
>  contact[i].surface.slip2 = 0.4;
>  contact[i].surface.soft_erp = 0.2;
>  contact[i].surface.soft_cfm = 0.2;
> for me this seems correct and it works perfectly for the feet, but 
> unfortunately and strange enough only for them

Have you tried changing cfm value? 
For me the following works:
 contact[i].surface.mode =  dContactSoftCFM;

 contact[i].surface.mode =  dContactBounce;

 contact[i].surface.mu = 100; //dInfinity;

 
contact[i].surface.soft_cfm = WORLD_CFM; // = 1.0e-5

 contact[i].surface.bounce = 0.04;
 
> 2.The real robot dog has a servo motor in hips and shoulders. I simulated that
> with a ball joint and an angularmotor, but I did not find a way toset the
> motor 
> to a certain angle. Some one told me it would be as simple as: 
>           AddMotorForce(desired angle - actual angle),
> but I did not find a way to realize this.

I used two hinge joints to represent shoulder and used "Stop and motor
parameters" (section 7.5 in user guide) - dJointSetHingeParam (FMax and Vel) to
get the desired angle and it is working for me.

double pValue=5, dValue=0.1;
//J3 = desired angle;
actualKneeAngle = dJointGetHingeAngle(kJoint.jointID);
jointError = (double)J3 - (double)actualKneeAngle;
jointRate = dJointGetHingeAngleRate(kJoint.jointID);
maxForce = 1900.0;
needVelocity = (pValue*jointError - dValue*jointRate);
dJointSetHingeParam(kJoint.jointID, 	dParamFMax,		maxForce);
dJointSetHingeParam(kJoint.jointID, 	dParamVel, 		needVelocity);


Regards,
Neelam

=====
________________________
Neelam C

http://www.geocities.com/tina_vipul/homepage.html


		
__________________________________ 
Do you Yahoo!? 
Check out the new Yahoo! Front Page. 
www.yahoo.com