//- Return current holding traction
Foam::scalar Foam::linearCohesiveLaw::traction(scalar delta) const
{
if (delta > deltaC().value())
{
return 0.0;
}
else if (delta < 0)
{
return sigmaMax().value();
}
return sigmaMax().value()*(1.0 - delta/deltaC().value());
}
//- Return current holding traction
Foam::scalar Foam::DugdaleCohesiveLaw::traction(scalar delta) const
{
if (delta > deltaC().value())
{
return 0.0;
}
else if (delta < 0)
{
return sigmaMax().value();
}
return sigmaMax().value();
}
bool IKTrajectoryHelper::computeIK(const double endEffectorTargetPosition[3],
const double endEffectorTargetOrientation[4],
const double endEffectorWorldPosition[3],
const double endEffectorWorldOrientation[4],
const double* q_current, int numQ,int endEffectorIndex,
double* q_new, int ikMethod, const double* linear_jacobian, const double* angular_jacobian, int jacobian_size, const double dampIk[6])
{
bool useAngularPart = (ikMethod==IK2_VEL_DLS_WITH_ORIENTATION || ikMethod==IK2_VEL_DLS_WITH_ORIENTATION_NULLSPACE) ? true : false;
Jacobian ikJacobian(useAngularPart,numQ);
ikJacobian.Reset();
bool UseJacobianTargets1 = false;
if ( UseJacobianTargets1 ) {
ikJacobian.SetJtargetActive();
}
else {
ikJacobian.SetJendActive();
}
VectorR3 targets;
targets.Set(endEffectorTargetPosition[0],endEffectorTargetPosition[1],endEffectorTargetPosition[2]);
ikJacobian.ComputeJacobian(&targets); // Set up Jacobian and deltaS vectors
// Set one end effector world position from Bullet
VectorRn deltaS(3);
for (int i = 0; i < 3; ++i)
{
deltaS.Set(i,dampIk[i]*(endEffectorTargetPosition[i]-endEffectorWorldPosition[i]));
}
// Set one end effector world orientation from Bullet
VectorRn deltaR(3);
if (useAngularPart)
{
btQuaternion startQ(endEffectorWorldOrientation[0],endEffectorWorldOrientation[1],endEffectorWorldOrientation[2],endEffectorWorldOrientation[3]);
btQuaternion endQ(endEffectorTargetOrientation[0],endEffectorTargetOrientation[1],endEffectorTargetOrientation[2],endEffectorTargetOrientation[3]);
btQuaternion deltaQ = endQ*startQ.inverse();
float angle = deltaQ.getAngle();
btVector3 axis = deltaQ.getAxis();
if (angle > PI) {
angle -= 2.0*PI;
}
else if (angle < -PI) {
angle += 2.0*PI;
}
float angleDot = angle;
btVector3 angularVel = angleDot*axis.normalize();
for (int i = 0; i < 3; ++i)
{
deltaR.Set(i,dampIk[i+3]*angularVel[i]);
}
}
{
if (useAngularPart)
{
VectorRn deltaC(6);
MatrixRmn completeJacobian(6,numQ);
for (int i = 0; i < 3; ++i)
{
deltaC.Set(i,deltaS[i]);
deltaC.Set(i+3,deltaR[i]);
for (int j = 0; j < numQ; ++j)
{
completeJacobian.Set(i,j,linear_jacobian[i*numQ+j]);
completeJacobian.Set(i+3,j,angular_jacobian[i*numQ+j]);
}
}
ikJacobian.SetDeltaS(deltaC);
ikJacobian.SetJendTrans(completeJacobian);
} else
{
VectorRn deltaC(3);
MatrixRmn completeJacobian(3,numQ);
for (int i = 0; i < 3; ++i)
{
deltaC.Set(i,deltaS[i]);
for (int j = 0; j < numQ; ++j)
{
completeJacobian.Set(i,j,linear_jacobian[i*numQ+j]);
}
}
ikJacobian.SetDeltaS(deltaC);
ikJacobian.SetJendTrans(completeJacobian);
}
}
// Calculate the change in theta values
switch (ikMethod) {
case IK2_JACOB_TRANS:
ikJacobian.CalcDeltaThetasTranspose(); // Jacobian transpose method
break;
case IK2_DLS:
case IK2_VEL_DLS:
case IK2_VEL_DLS_WITH_ORIENTATION:
//ikJacobian.CalcDeltaThetasDLS(); // Damped least squares method
assert(m_data->m_dampingCoeff.GetLength()==numQ);
ikJacobian.CalcDeltaThetasDLS2(m_data->m_dampingCoeff);
break;
case IK2_VEL_DLS_WITH_NULLSPACE:
case IK2_VEL_DLS_WITH_ORIENTATION_NULLSPACE:
assert(m_data->m_nullSpaceVelocity.GetLength()==numQ);
ikJacobian.CalcDeltaThetasDLSwithNullspace(m_data->m_nullSpaceVelocity);
break;
case IK2_DLS_SVD:
ikJacobian.CalcDeltaThetasDLSwithSVD();
break;
case IK2_PURE_PSEUDO:
ikJacobian.CalcDeltaThetasPseudoinverse(); // Pure pseudoinverse method
break;
case IK2_SDLS:
ikJacobian.CalcDeltaThetasSDLS(); // Selectively damped least squares method
break;
default:
ikJacobian.ZeroDeltaThetas();
break;
}
// Use for velocity IK, update theta dot
//ikJacobian.UpdateThetaDot();
// Use for position IK, incrementally update theta
//ikJacobian.UpdateThetas();
// Apply the change in the theta values
//ikJacobian.UpdatedSClampValue(&targets);
for (int i=0;i<numQ;i++)
{
// Use for velocity IK
q_new[i] = ikJacobian.dTheta[i] + q_current[i];
// Use for position IK
//q_new[i] = m_data->m_ikNodes[i]->GetTheta();
}
return true;
}