/// Get shaft direction, for 2nd pulley, in absolute reference public ChVector Get_shaft_dir2() { if (Body1 != null) { ChFrame <double> absframe = ChFrame <double> .FNULL;// new ChFrame<double>(); ((ChFrame <double>)Body2).TransformLocalToParent(local_shaft2, absframe); return(absframe.GetA().Get_A_Zaxis()); } else { return(ChVector.VECT_Z); } }
// // 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); }
// // 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); } }
/// Updates motion laws, marker positions, etc. public override void UpdateTime(double mytime) { // First, inherit to parent class base.UpdateTime(mytime); ChFrame <double> abs_shaft1 = ChFrame <double> .FNULL; //new ChFrame<double>(); ChFrame <double> abs_shaft2 = ChFrame <double> .FNULL; //new ChFrame<double>(); ((ChFrame <double>)Body1).TransformLocalToParent(local_shaft1, abs_shaft1); ((ChFrame <double>)Body2).TransformLocalToParent(local_shaft2, abs_shaft2); ChVector dcc_w = ChVector.Vsub(Get_shaft_pos2(), Get_shaft_pos1()); // compute actual rotation of the two wheels (relative to truss). ChVector md1 = abs_shaft1.GetA().MatrT_x_Vect(dcc_w); md1.z = 0; md1 = ChVector.Vnorm(md1); ChVector md2 = abs_shaft2.GetA().MatrT_x_Vect(dcc_w); md2.z = 0; md2 = ChVector.Vnorm(md2); double periodic_a1 = ChMaths.ChAtan2(md1.x, md1.y); double periodic_a2 = ChMaths.ChAtan2(md2.x, md2.y); double old_a1 = a1; double old_a2 = a2; double turns_a1 = Math.Floor(old_a1 / ChMaths.CH_C_2PI); double turns_a2 = Math.Floor(old_a2 / ChMaths.CH_C_2PI); double a1U = turns_a1 * ChMaths.CH_C_2PI + periodic_a1 + ChMaths.CH_C_2PI; double a1M = turns_a1 * ChMaths.CH_C_2PI + periodic_a1; double a1L = turns_a1 * ChMaths.CH_C_2PI + periodic_a1 - ChMaths.CH_C_2PI; a1 = a1M; if (Math.Abs(a1U - old_a1) < Math.Abs(a1M - old_a1)) { a1 = a1U; } if (Math.Abs(a1L - a1) < Math.Abs(a1M - a1)) { a1 = a1L; } double a2U = turns_a2 * ChMaths.CH_C_2PI + periodic_a2 + ChMaths.CH_C_2PI; double a2M = turns_a2 * ChMaths.CH_C_2PI + periodic_a2; double a2L = turns_a2 * ChMaths.CH_C_2PI + periodic_a2 - ChMaths.CH_C_2PI; a2 = a2M; if (Math.Abs(a2U - old_a2) < Math.Abs(a2M - old_a2)) { a2 = a2U; } if (Math.Abs(a2L - a2) < Math.Abs(a2M - a2)) { a2 = a2L; } // correct marker positions if phasing is not correct double m_delta = 0; if (checkphase) { double realtau = tau; m_delta = a1 - phase - (a2 / realtau); if (m_delta > ChMaths.CH_C_PI) { m_delta -= (ChMaths.CH_C_2PI); // range -180..+180 is better than 0...360 } if (m_delta > (ChMaths.CH_C_PI / 4.0)) { m_delta = (ChMaths.CH_C_PI / 4.0); // phase correction only in +/- 45° } if (m_delta < -(ChMaths.CH_C_PI / 4.0)) { m_delta = -(ChMaths.CH_C_PI / 4.0); } //***TODO*** } // Move markers 1 and 2 to align them as pulley ends ChVector d21_w = dcc_w - Get_shaft_dir1() * ChVector.Vdot(Get_shaft_dir1(), dcc_w); ChVector D21_w = ChVector.Vnorm(d21_w); shaft_dist = d21_w.Length(); ChVector U1_w = ChVector.Vcross(Get_shaft_dir1(), D21_w); double gamma1 = Math.Acos((r1 - r2) / shaft_dist); ChVector Ru_w = D21_w * Math.Cos(gamma1) + U1_w * Math.Sin(gamma1); ChVector Rl_w = D21_w * Math.Cos(gamma1) - U1_w * Math.Sin(gamma1); belt_up1 = Get_shaft_pos1() + Ru_w * r1; belt_low1 = Get_shaft_pos1() + Rl_w * r1; belt_up2 = Get_shaft_pos1() + d21_w + Ru_w * r2; belt_low2 = Get_shaft_pos1() + d21_w + Rl_w * r2; // marker alignment ChMatrix33 <double> maU = new ChMatrix33 <double>(0); ChMatrix33 <double> maL = new ChMatrix33 <double>(0); ChVector Dxu = ChVector.Vnorm(belt_up2 - belt_up1); ChVector Dyu = Ru_w; ChVector Dzu = ChVector.Vnorm(ChVector.Vcross(Dxu, Dyu)); Dyu = ChVector.Vnorm(ChVector.Vcross(Dzu, Dxu)); maU.Set_A_axis(Dxu, Dyu, Dzu); // ! Require that the BDF routine of marker won't handle speed and acc.calculus of the moved marker 2! marker2.SetMotionType(ChMarker.eChMarkerMotion.M_MOTION_EXTERNAL); marker1.SetMotionType(ChMarker.eChMarkerMotion.M_MOTION_EXTERNAL); ChCoordsys newmarkpos = new ChCoordsys(); // move marker1 in proper positions newmarkpos.pos = this.belt_up1; newmarkpos.rot = maU.Get_A_quaternion(); marker1.Impose_Abs_Coord(newmarkpos); // move marker1 into teeth position // move marker2 in proper positions newmarkpos.pos = this.belt_up2; newmarkpos.rot = maU.Get_A_quaternion(); marker2.Impose_Abs_Coord(newmarkpos); // move marker2 into teeth position double phase_correction_up = m_delta * r1; double phase_correction_low = -phase_correction_up; double hU = ChVector.Vlength(belt_up2 - belt_up1) + phase_correction_up; double hL = ChVector.Vlength(belt_low2 - belt_low1) + phase_correction_low; // imposed relative positions/speeds deltaC.pos = new ChVector(-hU, 0, 0); deltaC_dt.pos = ChVector.VNULL; deltaC_dtdt.pos = ChVector.VNULL; deltaC.rot = ChQuaternion.QUNIT; // no relative rotations imposed! deltaC_dt.rot = ChQuaternion.QNULL; deltaC_dtdt.rot = ChQuaternion.QNULL; }
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++; } } }
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 = this.frame1.BitShiftRight(this.Body1); ChFrame <double> aframe2 = this.frame2.BitShiftRight(this.Body2); ChFrame <double> aframe12 = new ChFrame <double>();// ChFrame<double>.FNULL; aframe2.TransformParentToLocal(aframe1, aframe12); ChFrame <double> aframe2rotating = new ChFrame <double>();// ChFrame<double>.FNULL; double aux_rotation; aux_rotation = m_func.Get_y(mytime) + rot_offset; aframe2rotating.SetRot(aframe2.GetRot() * ChQuaternion.Q_from_AngAxis2(aux_rotation, ChVector.VECT_Z)); ChFrame <double> aframe12rotating = new ChFrame <double>(); // aframe2rotating.TransformParentToLocal(aframe1, aframe12rotating); ChMatrix33 <double> Jw1 = new ChMatrix33 <double>(0), Jw2 = new ChMatrix33 <double>(0); ChMatrix33 <double> mtempM = new ChMatrix33 <double>(0), mtempQ = new ChMatrix33 <double>(0); 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(); // 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.nm.matrix[0, 0] = 0.5 * aframe12rotating.GetRot().e0; * mtempM.nm.matrix[1, 1] = 0.5 * aframe12rotating.GetRot().e0; * mtempM.nm.matrix[2, 2] = 0.5 * aframe12rotating.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) { 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++; } } }
// // UPDATING FUNCTIONS // /// Perform the update of this joint at the specified time: compute jacobians /// and constraint violations, cache in internal structures public override void update(double time, bool update_assets = true) { // Inherit time changes of parent class base.UpdateTime(time); // Express the joint frames in absolute frame ChFrame <double> frame1_abs = m_frame1.BitShiftRight(Body1); ChFrame <double> frame2_abs = m_frame2.BitShiftRight(Body2); // Calculate violations of the spherical constraints 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); // Compute Jacobian of the spherical constraints // pos2_abs - pos1_abs = 0 { ChMatrix33 <double> tilde1 = new ChMatrix33 <double>(0); ChMatrix33 <double> tilde2 = new ChMatrix33 <double>(0); tilde1.Set_X_matrix(m_frame1.coord.pos); tilde2.Set_X_matrix(m_frame2.coord.pos); ChMatrix33 <double> Phi_pi1 = Body1.GetA() * tilde1; ChMatrix33 <double> Phi_pi2 = Body2.GetA() * tilde2; m_cnstr_x.Get_Cq_a().ElementN(0) = -1; m_cnstr_x.Get_Cq_b().ElementN(0) = +1; m_cnstr_x.Get_Cq_a().ElementN(1) = 0; m_cnstr_x.Get_Cq_b().ElementN(1) = 0; m_cnstr_x.Get_Cq_a().ElementN(2) = 0; m_cnstr_x.Get_Cq_b().ElementN(2) = 0; m_cnstr_x.Get_Cq_a().ElementN(3) = Phi_pi1.nm.matrix[0, 0]; m_cnstr_x.Get_Cq_b().ElementN(3) = -Phi_pi2.nm.matrix[0, 0]; m_cnstr_x.Get_Cq_a().ElementN(4) = Phi_pi1.nm.matrix[0, 1]; m_cnstr_x.Get_Cq_b().ElementN(4) = -Phi_pi2.nm.matrix[0, 1]; m_cnstr_x.Get_Cq_a().ElementN(5) = Phi_pi1.nm.matrix[0, 2]; m_cnstr_x.Get_Cq_b().ElementN(5) = -Phi_pi2.nm.matrix[0, 2]; m_cnstr_y.Get_Cq_a().ElementN(0) = 0; m_cnstr_y.Get_Cq_b().ElementN(0) = 0; m_cnstr_y.Get_Cq_a().ElementN(1) = -1; m_cnstr_y.Get_Cq_b().ElementN(1) = +1; m_cnstr_y.Get_Cq_a().ElementN(2) = 0; m_cnstr_y.Get_Cq_b().ElementN(2) = 0; m_cnstr_y.Get_Cq_a().ElementN(3) = Phi_pi1.nm.matrix[1, 0]; m_cnstr_y.Get_Cq_b().ElementN(3) = -Phi_pi2.nm.matrix[1, 0]; m_cnstr_y.Get_Cq_a().ElementN(4) = Phi_pi1.nm.matrix[1, 1]; m_cnstr_y.Get_Cq_b().ElementN(4) = -Phi_pi2.nm.matrix[1, 1]; m_cnstr_y.Get_Cq_a().ElementN(5) = Phi_pi1.nm.matrix[1, 2]; m_cnstr_y.Get_Cq_b().ElementN(5) = -Phi_pi2.nm.matrix[1, 2]; m_cnstr_z.Get_Cq_a().ElementN(0) = 0; m_cnstr_z.Get_Cq_b().ElementN(0) = 0; m_cnstr_z.Get_Cq_a().ElementN(1) = 0; m_cnstr_z.Get_Cq_b().ElementN(1) = 0; m_cnstr_z.Get_Cq_a().ElementN(2) = -1; m_cnstr_z.Get_Cq_b().ElementN(2) = +1; m_cnstr_z.Get_Cq_a().ElementN(3) = Phi_pi1.nm.matrix[2, 0]; m_cnstr_z.Get_Cq_b().ElementN(3) = -Phi_pi2.nm.matrix[2, 0]; m_cnstr_z.Get_Cq_a().ElementN(4) = Phi_pi1.nm.matrix[2, 1]; m_cnstr_z.Get_Cq_b().ElementN(4) = -Phi_pi2.nm.matrix[2, 1]; m_cnstr_z.Get_Cq_a().ElementN(5) = Phi_pi1.nm.matrix[2, 2]; m_cnstr_z.Get_Cq_b().ElementN(5) = -Phi_pi2.nm.matrix[2, 2]; } // Calculate violation of the dot constraint ChVector u1 = frame1_abs.GetA().Get_A_Xaxis(); ChVector v2 = frame2_abs.GetA().Get_A_Yaxis(); m_C.matrix.SetElement(3, 0, ChVector.Vdot(u1, v2)); // Compute Jacobian of the dot constraint // dot(u1_abs, v2_abs) = 0 { ChMatrix33 <double> mat1 = Body1.GetA() * m_u1_tilde; ChMatrix33 <double> mat2 = Body2.GetA() * m_v2_tilde; ChVector Phi_pi1 = mat1.MatrT_x_Vect(v2); ChVector Phi_pi2 = mat2.MatrT_x_Vect(u1); m_cnstr_dot.Get_Cq_a().ElementN(0) = 0; m_cnstr_dot.Get_Cq_a().ElementN(1) = 0; m_cnstr_dot.Get_Cq_a().ElementN(2) = 0; m_cnstr_dot.Get_Cq_a().ElementN(3) = -Phi_pi1.x; m_cnstr_dot.Get_Cq_a().ElementN(4) = -Phi_pi1.y; m_cnstr_dot.Get_Cq_a().ElementN(5) = -Phi_pi1.z; m_cnstr_dot.Get_Cq_b().ElementN(0) = 0; m_cnstr_dot.Get_Cq_b().ElementN(1) = 0; m_cnstr_dot.Get_Cq_b().ElementN(2) = 0; m_cnstr_dot.Get_Cq_b().ElementN(3) = -Phi_pi2.x; m_cnstr_dot.Get_Cq_b().ElementN(4) = -Phi_pi2.y; m_cnstr_dot.Get_Cq_b().ElementN(5) = -Phi_pi2.z; } }
// // 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++; } } }
// Updates motion laws, marker positions, etc. public override void UpdateTime(double mytime) { // First, inherit to parent class base.UpdateTime(mytime); // Move markers 1 and 2 to align them as gear teeth ChMatrix33 <double> ma1 = new ChMatrix33 <double>(0); ChMatrix33 <double> ma2 = new ChMatrix33 <double>(0); ChMatrix33 <double> mrotma = new ChMatrix33 <double>(0); ChMatrix33 <double> marot_beta = new ChMatrix33 <double>(0); ChVector mx; ChVector my; ChVector mz; ChVector mr; ChVector mmark1; ChVector mmark2; ChVector lastX; ChVector vrota; ChCoordsys newmarkpos = new ChCoordsys(new ChVector(0, 0, 0), new ChQuaternion(1, 0, 0, 0)); ChFrame <double> abs_shaft1 = ChFrame <double> .FNULL; // new ChFrame<double>(); ChFrame <double> abs_shaft2 = ChFrame <double> .FNULL; //new ChFrame<double>(); ((ChFrame <double>)Body1).TransformLocalToParent(local_shaft1, abs_shaft1); ((ChFrame <double>)Body2).TransformLocalToParent(local_shaft2, abs_shaft2); ChVector vbdist = ChVector.Vsub(Get_shaft_pos1(), Get_shaft_pos2()); // ChVector Trad1 = ChVector.Vnorm(ChVector.Vcross(Get_shaft_dir1(), ChVector.Vnorm(ChVector.Vcross(Get_shaft_dir1(), vbdist)))); // ChVector Trad2 = ChVector.Vnorm(ChVector.Vcross(ChVector.Vnorm(ChVector.Vcross(Get_shaft_dir2(), vbdist)), Get_shaft_dir2())); double dist = ChVector.Vlength(vbdist); // compute actual rotation of the two wheels (relative to truss). ChVector md1 = abs_shaft1.GetA().MatrT_x_Vect(-vbdist); md1.z = 0; md1 = ChVector.Vnorm(md1); ChVector md2 = abs_shaft2.GetA().MatrT_x_Vect(-vbdist); md2.z = 0; md2 = ChVector.Vnorm(md2); double periodic_a1 = ChMaths.ChAtan2(md1.x, md1.y); double periodic_a2 = ChMaths.ChAtan2(md2.x, md2.y); double old_a1 = a1; double old_a2 = a2; double turns_a1 = Math.Floor(old_a1 / ChMaths.CH_C_2PI); double turns_a2 = Math.Floor(old_a2 / ChMaths.CH_C_2PI); double a1U = turns_a1 * ChMaths.CH_C_2PI + periodic_a1 + ChMaths.CH_C_2PI; double a1M = turns_a1 * ChMaths.CH_C_2PI + periodic_a1; double a1L = turns_a1 * ChMaths.CH_C_2PI + periodic_a1 - ChMaths.CH_C_2PI; a1 = a1M; if (Math.Abs(a1U - old_a1) < Math.Abs(a1M - old_a1)) { a1 = a1U; } if (Math.Abs(a1L - a1) < Math.Abs(a1M - a1)) { a1 = a1L; } double a2U = turns_a2 * ChMaths.CH_C_2PI + periodic_a2 + ChMaths.CH_C_2PI; double a2M = turns_a2 * ChMaths.CH_C_2PI + periodic_a2; double a2L = turns_a2 * ChMaths.CH_C_2PI + periodic_a2 - ChMaths.CH_C_2PI; a2 = a2M; if (Math.Abs(a2U - old_a2) < Math.Abs(a2M - old_a2)) { a2 = a2U; } if (Math.Abs(a2L - a2) < Math.Abs(a2M - a2)) { a2 = a2L; } // compute new markers coordsystem alignment my = ChVector.Vnorm(vbdist); mz = Get_shaft_dir1(); mx = ChVector.Vnorm(ChVector.Vcross(my, mz)); mr = ChVector.Vnorm(ChVector.Vcross(mz, mx)); mz = ChVector.Vnorm(ChVector.Vcross(mx, my)); ChVector mz2, mx2, mr2, my2; my2 = my; mz2 = Get_shaft_dir2(); mx2 = ChVector.Vnorm(ChVector.Vcross(my2, mz2)); mr2 = ChVector.Vnorm(ChVector.Vcross(mz2, mx2)); ma1.Set_A_axis(mx, my, mz); // rotate csys because of beta vrota.x = 0.0; vrota.y = beta; vrota.z = 0.0; mrotma.Set_A_Rxyz(vrota); marot_beta.nm.matrix.MatrMultiply(ma1.nm.matrix, mrotma.nm.matrix); // rotate csys because of alpha vrota.x = 0.0; vrota.y = 0.0; vrota.z = alpha; if (react_force.x < 0) { vrota.z = alpha; } else { vrota.z = -alpha; } mrotma.Set_A_Rxyz(vrota); ma1.nm.matrix.MatrMultiply(marot_beta.nm.matrix, mrotma.nm.matrix); ma2.nm.matrix.CopyFromMatrix(ma1.nm.matrix); // is a bevel gear? double be = Math.Acos(ChVector.Vdot(Get_shaft_dir1(), Get_shaft_dir2())); bool is_bevel = true; if (Math.Abs(ChVector.Vdot(Get_shaft_dir1(), Get_shaft_dir2())) > 0.96) { is_bevel = false; } // compute wheel radii so that: // w2 = - tau * w1 if (!is_bevel) { double pardist = ChVector.Vdot(mr, vbdist); double inv_tau = 1.0 / tau; if (!epicyclic) { r2 = pardist - pardist / (inv_tau + 1.0); } else { r2 = pardist - (tau * pardist) / (tau - 1.0); } r1 = r2 * tau; } else { double gamma2; if (!epicyclic) { gamma2 = be / (tau + 1.0); } else { gamma2 = be / (-tau + 1.0); } double al = ChMaths.CH_C_PI - Math.Acos(ChVector.Vdot(Get_shaft_dir2(), my)); double te = ChMaths.CH_C_PI - al - be; double fd = Math.Sin(te) * (dist / Math.Sin(be)); r2 = fd * Math.Tan(gamma2); r1 = r2 * tau; } // compute markers positions, supposing they // stay on the ideal wheel contact point mmark1 = ChVector.Vadd(Get_shaft_pos2(), ChVector.Vmul(mr2, r2)); mmark2 = mmark1; contact_pt = mmark1; // correct marker 1 position if phasing is not correct if (checkphase) { double realtau = tau; if (epicyclic) { realtau = -tau; } double m_delta; m_delta = -(a2 / realtau) - a1 - phase; if (m_delta > ChMaths.CH_C_PI) { m_delta -= (ChMaths.CH_C_2PI); // range -180..+180 is better than 0...360 } if (m_delta > (ChMaths.CH_C_PI / 4.0)) { m_delta = (ChMaths.CH_C_PI / 4.0); // phase correction only in +/- 45° } if (m_delta < -(ChMaths.CH_C_PI / 4.0)) { m_delta = -(ChMaths.CH_C_PI / 4.0); } vrota.x = vrota.y = 0.0; vrota.z = -m_delta; mrotma.Set_A_Rxyz(vrota); // rotate about Z of shaft to correct mmark1 = abs_shaft1.GetA().MatrT_x_Vect(ChVector.Vsub(mmark1, Get_shaft_pos1())); mmark1 = mrotma.Matr_x_Vect(mmark1); mmark1 = ChVector.Vadd(abs_shaft1.GetA().Matr_x_Vect(mmark1), Get_shaft_pos1()); } // Move Shaft 1 along its direction if not aligned to wheel double offset = ChVector.Vdot(Get_shaft_dir1(), (contact_pt - Get_shaft_pos1())); ChVector moff = Get_shaft_dir1() * offset; if (Math.Abs(offset) > 0.0001) { local_shaft1.SetPos(local_shaft1.GetPos() + Body1.TransformDirectionParentToLocal(moff)); } // ! Require that the BDF routine of marker won't handle speed and acc.calculus of the moved marker 2! marker2.SetMotionType(ChMarker.eChMarkerMotion.M_MOTION_EXTERNAL); marker1.SetMotionType(ChMarker.eChMarkerMotion.M_MOTION_EXTERNAL); // move marker1 in proper positions newmarkpos.pos = mmark1; newmarkpos.rot = ma1.Get_A_quaternion(); marker1.Impose_Abs_Coord(newmarkpos); // move marker1 into teeth position // move marker2 in proper positions newmarkpos.pos = mmark2; newmarkpos.rot = ma2.Get_A_quaternion(); marker2.Impose_Abs_Coord(newmarkpos); // move marker2 into teeth position // imposed relative positions/speeds deltaC.pos = ChVector.VNULL; deltaC_dt.pos = ChVector.VNULL; deltaC_dtdt.pos = ChVector.VNULL; deltaC.rot = ChQuaternion.QUNIT; // no relative rotations imposed! deltaC_dt.rot = ChQuaternion.QNULL; deltaC_dtdt.rot = ChQuaternion.QNULL; }