//
// SOLVER INTERFACE (OLD)
//
public override void ConstraintsFbLoadForces(double factor = 1)
{
// compute instant torque
double mT = m_func.Get_y(this.GetChTime());
ChFrame <double> aframe1 = ChFrame <double> .BitShiftRight(this.frame1, (this.Body1));
ChFrame <double> aframe2 = ChFrame <double> .BitShiftRight(this.frame2, (this.Body2));
ChVector m_abs_torque = aframe2.GetA().Matr_x_Vect(new ChVector(0, 0, mT));
Body2.Variables().Get_fb().matrix.PasteSumVector(Body2.TransformDirectionParentToLocal(m_abs_torque) * -factor, 3, 0);
Body1.Variables().Get_fb().matrix.PasteSumVector(Body1.TransformDirectionParentToLocal(m_abs_torque) * factor, 3, 0);
}
/// Initialize this joint by specifying the two bodies to be connected and the
/// joint frames on each body. If local = true, it is assumed that these quantities
/// are specified in the local body frames. Otherwise, it is assumed that they are
/// specified in the absolute frame.
public void Initialize(ChBodyFrame body1, //< first body frame
ChBodyFrame body2, //< second body frame
bool local, //< true if data given in body local frames
ChFrame <double> frame1, //< joint frame on body 1
ChFrame <double> frame2 //< joint frame on body 2
)
{
Body1 = body1;
Body2 = body2;
m_cnstr_x.SetVariables(Body1.Variables(), Body2.Variables());
m_cnstr_y.SetVariables(Body1.Variables(), Body2.Variables());
m_cnstr_z.SetVariables(Body1.Variables(), Body2.Variables());
m_cnstr_dot.SetVariables(Body1.Variables(), Body2.Variables());
ChFrame <double> frame1_abs;
ChFrame <double> frame2_abs;
if (local)
{
m_frame1 = frame1;
m_frame2 = frame2;
frame1_abs = ChFrame <double> .BitShiftRight(frame1, Body1);
frame2_abs = ChFrame <double> .BitShiftRight(frame2, Body2);
}
else
{
((ChFrame <double>)Body1).TransformParentToLocal(frame1, m_frame1);
((ChFrame <double>)Body2).TransformParentToLocal(frame2, m_frame2);
frame1_abs = frame1;
frame2_abs = frame2;
}
m_u1_tilde.Set_X_matrix(m_frame1.GetA().Get_A_Xaxis());
m_v2_tilde.Set_X_matrix(m_frame2.GetA().Get_A_Yaxis());
m_C.matrix.SetElement(0, 0, frame2_abs.coord.pos.x - frame1_abs.coord.pos.x);
m_C.matrix.SetElement(1, 0, frame2_abs.coord.pos.y - frame1_abs.coord.pos.y);
m_C.matrix.SetElement(2, 0, frame2_abs.coord.pos.z - frame1_abs.coord.pos.z);
m_C.matrix.SetElement(3, 0, ChVector.Vdot(frame1_abs.GetA().Get_A_Xaxis(), frame2_abs.GetA().Get_A_Yaxis()));
}
//
// STATE FUNCTIONS
//
public override void IntLoadResidual_F(int off, ref ChVectorDynamic <double> R, double c)
{
// compute instant torque
double mT = m_func.Get_y(this.GetChTime());
ChFrame <double> aframe1 = ChFrame <double> .BitShiftRight(this.frame1, (this.Body1));
ChFrame <double> aframe2 = ChFrame <double> .BitShiftRight(this.frame2, (this.Body2));
ChVector m_abs_torque = aframe2.GetA().Matr_x_Vect(new ChVector(0, 0, mT));
if (Body2.Variables().IsActive())
{
R.matrix.PasteSumVector(Body2.TransformDirectionParentToLocal(m_abs_torque) * -c, Body2.Variables().GetOffset() + 3,
0);
}
if (Body1.Variables().IsActive())
{
R.matrix.PasteSumVector(Body1.TransformDirectionParentToLocal(m_abs_torque) * c, Body1.Variables().GetOffset() + 3,
0);
}
}
public override void update(double mytime, bool update_assets)
{
// Inherit parent class:
base.update(mytime, update_assets);
// Override the rotational jacobian [Cq] and the rotational residual C,
// by assuming an additional hidden frame that rotates about frame2:
if (this.Body1 != null && this.Body2 != null)
{
ChFrame <double> aframe1 = ChFrame <double> .BitShiftRight(this.frame1, (this.Body1));
ChFrame <double> aframe2 = ChFrame <double> .BitShiftRight(this.frame2, (this.Body2));
ChFrame <double> aframe12 = new ChFrame <double>();
aframe2.TransformParentToLocal(aframe1, aframe12);
ChFrame <double> aframe2rotating = new ChFrame <double>();
double aux_rotation;
if (this.avoid_angle_drift)
{
aux_rotation = this.aux_dt + this.rot_offset;
}
else
{
// to have it aligned to current rot, to allow C=0.
aux_rotation = aframe12.GetRot().Q_to_Rotv().z;
}
aframe2rotating.SetRot(aframe2.GetRot() * ChQuaternion.Q_from_AngAxis2(aux_rotation, ChVector.VECT_Z));
// TODO this needs to be addressed, with it it causes rotation problems, seems to work fine without the TransformParentToLocal?
ChFrame <double> aframe12rotating = new ChFrame <double>();
// aframe2rotating.TransformParentToLocal(aframe1, aframe12rotating);
ChMatrix33 <double> Jw1 = new ChMatrix33 <double>();
ChMatrix33 <double> Jw2 = new ChMatrix33 <double>();
ChMatrix33 <double> mtempM = new ChMatrix33 <double>();
ChMatrix33 <double> mtempQ = new ChMatrix33 <double>();
ChMatrix33 <double> abs_plane_rotating = aframe2rotating.GetA();
Jw1.nm.matrix.MatrTMultiply(abs_plane_rotating.nm.matrix, Body1.GetA().nm.matrix);
Jw2.nm.matrix.MatrTMultiply(abs_plane_rotating.nm.matrix, Body2.GetA().nm.matrix);
Jw2.nm.matrix.MatrNeg();
// TODO this also needs to be addressed, with it it causes rotation problems/
// Premultiply by Jw1 and Jw2 by 0.5*[Fp(q_resid)]' to get residual as imaginary part of a quaternion.
/* mtempM.Set_X_matrix((aframe12rotating.GetRot().GetVector()) * 0.5);
* mtempM[0, 0] = 0.5 * aframe12rotating.GetRot().e0;
* mtempM[1, 1] = 0.5 * aframe12rotating.GetRot().e0;
* mtempM[2, 2] = 0.5 * aframe12rotating.GetRot().e0;
* mtempQ.MatrTMultiply(mtempM, Jw1);
* Jw1 = mtempQ;
* mtempQ.MatrTMultiply(mtempM, Jw2);
* Jw2 = mtempQ;*/
int nc = 0;
if (c_x)
{
nc++;
}
if (c_y)
{
nc++;
}
if (c_z)
{
nc++;
}
if (c_rx)
{
this.C.matrix.ElementN(nc) = aframe12rotating.GetRot().e1;
this.mask.Constr_N(nc).Get_Cq_a().FillElem(0);
this.mask.Constr_N(nc).Get_Cq_b().FillElem(0);
this.mask.Constr_N(nc).Get_Cq_a().PasteClippedMatrix(Jw1.nm.matrix, 0, 0, 1, 3, 0, 3);
this.mask.Constr_N(nc).Get_Cq_b().PasteClippedMatrix(Jw2.nm.matrix, 0, 0, 1, 3, 0, 3);
nc++;
}
if (c_ry)
{
this.C.matrix.ElementN(nc) = aframe12rotating.GetRot().e2;
this.mask.Constr_N(nc).Get_Cq_a().FillElem(0);
this.mask.Constr_N(nc).Get_Cq_b().FillElem(0);
this.mask.Constr_N(nc).Get_Cq_a().PasteClippedMatrix(Jw1.nm.matrix, 1, 0, 1, 3, 0, 3);
this.mask.Constr_N(nc).Get_Cq_b().PasteClippedMatrix(Jw2.nm.matrix, 1, 0, 1, 3, 0, 3);
nc++;
}
if (c_rz)
{
this.C.matrix.ElementN(nc) = aframe12rotating.GetRot().e3;
this.mask.Constr_N(nc).Get_Cq_a().FillElem(0);
this.mask.Constr_N(nc).Get_Cq_b().FillElem(0);
this.mask.Constr_N(nc).Get_Cq_a().PasteClippedMatrix(Jw1.nm.matrix, 2, 0, 1, 3, 0, 3);
this.mask.Constr_N(nc).Get_Cq_b().PasteClippedMatrix(Jw2.nm.matrix, 2, 0, 1, 3, 0, 3);
nc++;
}
}
}
/// Get the joint frame on Body2, expressed in absolute coordinate system.
public ChFrame <double> GetFrame2Abs()
{
return(ChFrame <double> .BitShiftRight(m_frame2, Body2));
}
/// Get the joint frame on Body1, expressed in absolute coordinate system.
public ChFrame <double> GetFrame1Abs()
{
return(ChFrame <double> .BitShiftRight(m_frame1, Body1));
}
//
// UPDATING FUNCTIONS
//
/// Override _all_ time, jacobian etc. updating.
public override void update(double mytime, bool update_assets = true)
{
// Inherit time changes of parent class (ChLink), basically doing nothing :)
base.update(mytime, update_assets);
if (this.Body1 != null && this.Body2 != null)
{
this.mask.SetTwoBodiesVariables(Body1.Variables(), Body2.Variables());
ChFrame <double> aframe = ChFrame <double> .BitShiftRight(this.frame1, (this.Body1));
ChVector p1_abs = aframe.GetPos();
ChFrame <double> aframe2 = ChFrame <double> .BitShiftRight(this.frame2, (this.Body2));
ChVector p2_abs = aframe2.GetPos();
ChFrame <double> bframe = new ChFrame <double>();
(this.Body2).TransformParentToLocal(aframe, bframe);
this.frame2.TransformParentToLocal(bframe, aframe);
// Now 'aframe' contains the position/rotation of frame 1 respect to frame 2, in frame 2 coords.
//***TODO*** check if it is faster to do aframe2.TransformParentToLocal(aframe, bframe); instead of two transforms above
ChMatrix33 <double> Jx1 = new ChMatrix33 <double>(0);
ChMatrix33 <double> Jx2 = new ChMatrix33 <double>(0);
ChMatrix33 <double> Jr1 = new ChMatrix33 <double>(0);
ChMatrix33 <double> Jr2 = new ChMatrix33 <double>(0);
ChMatrix33 <double> Jw1 = new ChMatrix33 <double>(0);
ChMatrix33 <double> Jw2 = new ChMatrix33 <double>(0);
ChMatrix33 <double> mtempM = new ChMatrix33 <double>(0);
ChMatrix33 <double> mtempQ = new ChMatrix33 <double>(0);
ChMatrix33 <double> abs_plane = new ChMatrix33 <double>(0);
abs_plane.nm.matrix.MatrMultiply(Body2.GetA().nm.matrix, frame2.GetA().nm.matrix);
Jx1.nm.matrix.CopyFromMatrixT(abs_plane.nm.matrix);
Jx2.nm.matrix.CopyFromMatrixT(abs_plane.nm.matrix);
Jx2.nm.matrix.MatrNeg();
Jw1.nm.matrix.MatrTMultiply(abs_plane.nm.matrix, Body1.GetA().nm.matrix);
Jw2.nm.matrix.MatrTMultiply(abs_plane.nm.matrix, Body2.GetA().nm.matrix);
mtempM.Set_X_matrix(frame1.GetPos());
Jr1.nm.matrix.MatrMultiply(Jw1.nm.matrix, mtempM.nm.matrix);
Jr1.nm.matrix.MatrNeg();
mtempM.Set_X_matrix(frame2.GetPos());
Jr2.nm.matrix.MatrMultiply(Jw2.nm.matrix, mtempM.nm.matrix);
ChVector p2p1_base2 = (Body2.GetA()).MatrT_x_Vect(ChVector.Vsub(p1_abs, p2_abs));
mtempM.Set_X_matrix(p2p1_base2);
mtempQ.nm.matrix.MatrTMultiply(frame2.GetA().nm.matrix, mtempM.nm.matrix);
Jr2.nm.matrix.MatrInc(mtempQ.nm.matrix);
Jw2.nm.matrix.MatrNeg();
// Premultiply by Jw1 and Jw2 by 0.5*[Fp(q_resid)]' to get residual as imaginary part of a quaternion.
// For small misalignment this effect is almost insignificant cause [Fp(q_resid)]=[I],
// but otherwise it is needed (if you want to use the stabilization term - if not, you can live without).
mtempM.Set_X_matrix((aframe.GetRot().GetVector()) * 0.5);
mtempM.nm.matrix[0, 0] = 0.5 * aframe.GetRot().e0;
mtempM.nm.matrix[1, 1] = 0.5 * aframe.GetRot().e0;
mtempM.nm.matrix[2, 2] = 0.5 * aframe.GetRot().e0;
mtempQ.nm.matrix.MatrTMultiply(mtempM.nm.matrix, Jw1.nm.matrix);
Jw1 = mtempQ;
mtempQ.nm.matrix.MatrTMultiply(mtempM.nm.matrix, Jw2.nm.matrix);
Jw2 = mtempQ;
int nc = 0;
if (c_x)
{
this.C.matrix.ElementN(nc) = aframe.GetPos().x;
this.mask.Constr_N(nc).Get_Cq_a().PasteClippedMatrix(Jx1.nm.matrix, 0, 0, 1, 3, 0, 0);
this.mask.Constr_N(nc).Get_Cq_a().PasteClippedMatrix(Jr1.nm.matrix, 0, 0, 1, 3, 0, 3);
this.mask.Constr_N(nc).Get_Cq_b().PasteClippedMatrix(Jx2.nm.matrix, 0, 0, 1, 3, 0, 0);
this.mask.Constr_N(nc).Get_Cq_b().PasteClippedMatrix(Jr2.nm.matrix, 0, 0, 1, 3, 0, 3);
nc++;
}
if (c_y)
{
this.C.matrix.ElementN(nc) = aframe.GetPos().y;
this.mask.Constr_N(nc).Get_Cq_a().PasteClippedMatrix(Jx1.nm.matrix, 1, 0, 1, 3, 0, 0);
this.mask.Constr_N(nc).Get_Cq_a().PasteClippedMatrix(Jr1.nm.matrix, 1, 0, 1, 3, 0, 3);
this.mask.Constr_N(nc).Get_Cq_b().PasteClippedMatrix(Jx2.nm.matrix, 1, 0, 1, 3, 0, 0);
this.mask.Constr_N(nc).Get_Cq_b().PasteClippedMatrix(Jr2.nm.matrix, 1, 0, 1, 3, 0, 3);
nc++;
}
if (c_z)
{
this.C.matrix.ElementN(nc) = aframe.GetPos().z;
this.mask.Constr_N(nc).Get_Cq_a().PasteClippedMatrix(Jx1.nm.matrix, 2, 0, 1, 3, 0, 0);
this.mask.Constr_N(nc).Get_Cq_a().PasteClippedMatrix(Jr1.nm.matrix, 2, 0, 1, 3, 0, 3);
this.mask.Constr_N(nc).Get_Cq_b().PasteClippedMatrix(Jx2.nm.matrix, 2, 0, 1, 3, 0, 0);
this.mask.Constr_N(nc).Get_Cq_b().PasteClippedMatrix(Jr2.nm.matrix, 2, 0, 1, 3, 0, 3);
nc++;
}
if (c_rx)
{
this.C.matrix.ElementN(nc) = aframe.GetRot().e1;
this.mask.Constr_N(nc).Get_Cq_a().FillElem(0);
this.mask.Constr_N(nc).Get_Cq_b().FillElem(0);
this.mask.Constr_N(nc).Get_Cq_a().PasteClippedMatrix(Jw1.nm.matrix, 0, 0, 1, 3, 0, 3);
this.mask.Constr_N(nc).Get_Cq_b().PasteClippedMatrix(Jw2.nm.matrix, 0, 0, 1, 3, 0, 3);
nc++;
}
if (c_ry)
{
this.C.matrix.ElementN(nc) = aframe.GetRot().e2;
this.mask.Constr_N(nc).Get_Cq_a().FillElem(0);
this.mask.Constr_N(nc).Get_Cq_b().FillElem(0);
this.mask.Constr_N(nc).Get_Cq_a().PasteClippedMatrix(Jw1.nm.matrix, 1, 0, 1, 3, 0, 3);
this.mask.Constr_N(nc).Get_Cq_b().PasteClippedMatrix(Jw2.nm.matrix, 1, 0, 1, 3, 0, 3);
nc++;
}
if (c_rz)
{
this.C.matrix.ElementN(nc) = aframe.GetRot().e3;
this.mask.Constr_N(nc).Get_Cq_a().FillElem(0);
this.mask.Constr_N(nc).Get_Cq_b().FillElem(0);
this.mask.Constr_N(nc).Get_Cq_a().PasteClippedMatrix(Jw1.nm.matrix, 2, 0, 1, 3, 0, 3);
this.mask.Constr_N(nc).Get_Cq_b().PasteClippedMatrix(Jw2.nm.matrix, 2, 0, 1, 3, 0, 3);
nc++;
}
}
}
