Exemplo n.º 1
0
 /// 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);
     }
 }
Exemplo n.º 2
0
        //
        // 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);
        }
Exemplo n.º 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);
            }
        }
Exemplo n.º 4
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;
        }
Exemplo n.º 5
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++;
                }
            }
        }
Exemplo n.º 6
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 = 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++;
                }
            }
        }
Exemplo n.º 7
0
        //
        // 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;
            }
        }
Exemplo n.º 8
0
        //
        // 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++;
                }
            }
        }
Exemplo n.º 9
0
        // 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;
        }