system accelerations vector:

[Musa Audu]

We have a system with three degrees-of-freedom and we set out to solve for the accelerations
given the position, velocity and torque values. Our code looks like the following:

Code: Select all

	const ForceSet& fSet = model.getForceSet();
	for (i = 0; i < numActuators; i++)
	{
		ScalarActuator* act = dynamic_cast<ScalarActuator*>(&fSet.get(i));
		if (act) 
			act->setOverrideActuation(state, -jTorques[i]);
	}

	model.getMultibodySystem().realize(state, SimTK::Stage::Acceleration);
	SimTK::Vector udot = model.getMatterSubsystem().getUDot(state);

	for (i = 0; i < numActuators; i++)
		xDot[i] = udot[i];

With this code, however, we realize that the accelerations returned remain
insensitive to the applied joint torques. Can someone let us know what is
wrong with the code?

[Nicos Haralabidis]

Hey Musa,

I think before:

Code: Select all

act->setOverrideActuation(state, -jTorques[i]);

you need to include:

Code: Select all

act->overrideActuation(state,1);

Hopefully that works!

Nicos

[Musa Audu]

Hi Nicos,
That works perfectly. Thank you very much.