X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=src%2FFDM%2FJSBSim%2Fmodels%2FFGPropagate.cpp;h=4d1ef44a858a60d532d336d532d30f10673ced8c;hb=4f364af6d178d947eae1a5a751e3a9542b270069;hp=0fec89b0ca6cfc4f4e4110b6ed7679d52fb683ba;hpb=02fb83c774020633cb62e3b8154337510bed1de3;p=flightgear.git diff --git a/src/FDM/JSBSim/models/FGPropagate.cpp b/src/FDM/JSBSim/models/FGPropagate.cpp index 0fec89b0c..4d1ef44a8 100644 --- a/src/FDM/JSBSim/models/FGPropagate.cpp +++ b/src/FDM/JSBSim/models/FGPropagate.cpp @@ -71,14 +71,15 @@ using namespace std; namespace JSBSim { -static const char *IdSrc = "$Id: FGPropagate.cpp,v 1.71 2010/10/15 11:34:09 jberndt Exp $"; +static const char *IdSrc = "$Id: FGPropagate.cpp,v 1.76 2011/01/16 16:10:59 bcoconni Exp $"; static const char *IdHdr = ID_PROPAGATE; /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% CLASS IMPLEMENTATION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/ -FGPropagate::FGPropagate(FGFDMExec* fdmex) : FGModel(fdmex) +FGPropagate::FGPropagate(FGFDMExec* fdmex) : FGModel(fdmex), +LocalTerrainRadius(0), SeaLevelRadius(0), VehicleRadius(0) { Debug(0); Name = "FGPropagate"; @@ -94,7 +95,6 @@ FGPropagate::FGPropagate(FGFDMExec* fdmex) : FGModel(fdmex) integrator_rotational_position = eAdamsBashforth2; integrator_translational_position = eTrapezoidal; - VState.dqPQRdot.resize(4, FGColumnVector3(0.0,0.0,0.0)); VState.dqPQRidot.resize(4, FGColumnVector3(0.0,0.0,0.0)); VState.dqUVWidot.resize(4, FGColumnVector3(0.0,0.0,0.0)); VState.dqInertialVelocity.resize(4, FGColumnVector3(0.0,0.0,0.0)); @@ -118,18 +118,17 @@ bool FGPropagate::InitModel(void) if (!FGModel::InitModel()) return false; // For initialization ONLY: - SeaLevelRadius = LocalTerrainRadius = Inertial->GetRefRadius(); + SeaLevelRadius = LocalTerrainRadius = FDMExec->GetInertial()->GetRefRadius(); VState.vLocation.SetRadius( LocalTerrainRadius + 4.0 ); - VState.vLocation.SetEllipse(Inertial->GetSemimajor(), Inertial->GetSemiminor()); - vOmegaEarth = FGColumnVector3( 0.0, 0.0, Inertial->omega() ); // Earth rotation vector + VState.vLocation.SetEllipse(FDMExec->GetInertial()->GetSemimajor(), FDMExec->GetInertial()->GetSemiminor()); + vOmegaEarth = FGColumnVector3( 0.0, 0.0, FDMExec->GetInertial()->omega() ); // Earth rotation vector vPQRdot.InitMatrix(); vQtrndot = FGQuaternion(0,0,0); vUVWdot.InitMatrix(); vInertialVelocity.InitMatrix(); - VState.dqPQRdot.resize(4, FGColumnVector3(0.0,0.0,0.0)); VState.dqPQRidot.resize(4, FGColumnVector3(0.0,0.0,0.0)); VState.dqUVWidot.resize(4, FGColumnVector3(0.0,0.0,0.0)); VState.dqInertialVelocity.resize(4, FGColumnVector3(0.0,0.0,0.0)); @@ -157,10 +156,10 @@ void FGPropagate::SetInitialState(const FGInitialCondition *FGIC) FGIC->GetLatitudeRadIC(), FGIC->GetAltitudeASLFtIC() + FGIC->GetSeaLevelRadiusFtIC() ); - VState.vLocation.SetEarthPositionAngle(Inertial->GetEarthPositionAngle()); + VState.vLocation.SetEarthPositionAngle(FDMExec->GetInertial()->GetEarthPositionAngle()); - Ti2ec = GetTi2ec(); // ECI to ECEF transform - Tec2i = Ti2ec.Transposed(); // ECEF to ECI frame transform + Ti2ec = VState.vLocation.GetTi2ec(); // ECI to ECEF transform + Tec2i = Ti2ec.Transposed(); // ECEF to ECI frame transform VState.vInertialPosition = Tec2i * VState.vLocation; @@ -259,11 +258,11 @@ bool FGPropagate::Run(void) // matrices that are consistent with the new state of the vehicle // 1. Update the Earth position angle (EPA) - VState.vLocation.SetEarthPositionAngle(Inertial->GetEarthPositionAngle()); + VState.vLocation.SetEarthPositionAngle(FDMExec->GetInertial()->GetEarthPositionAngle()); // 2. Update the Ti2ec and Tec2i transforms from the updated EPA - Ti2ec = GetTi2ec(); // ECI to ECEF transform - Tec2i = Ti2ec.Transposed(); // ECEF to ECI frame transform + Ti2ec = VState.vLocation.GetTi2ec(); // ECI to ECEF transform + Tec2i = Ti2ec.Transposed(); // ECEF to ECI frame transform // 3. Update the location from the updated Ti2ec and inertial position VState.vLocation = Ti2ec*VState.vInertialPosition; @@ -314,9 +313,9 @@ bool FGPropagate::Run(void) void FGPropagate::CalculatePQRdot(void) { - const FGColumnVector3& vMoments = Aircraft->GetMoments(); // current moments - const FGMatrix33& J = MassBalance->GetJ(); // inertia matrix - const FGMatrix33& Jinv = MassBalance->GetJinv(); // inertia matrix inverse + const FGColumnVector3& vMoments = FDMExec->GetAircraft()->GetMoments(); // current moments + const FGMatrix33& J = FDMExec->GetMassBalance()->GetJ(); // inertia matrix + const FGMatrix33& Jinv = FDMExec->GetMassBalance()->GetJinv(); // inertia matrix inverse // Compute body frame rotational accelerations based on the current body // moments and the total inertial angular velocity expressed in the body @@ -358,8 +357,8 @@ void FGPropagate::CalculateQuatdot(void) void FGPropagate::CalculateUVWdot(void) { - double mass = MassBalance->GetMass(); // mass - const FGColumnVector3& vForces = Aircraft->GetForces(); // current forces + double mass = FDMExec->GetMassBalance()->GetMass(); // mass + const FGColumnVector3& vForces = FDMExec->GetAircraft()->GetForces(); // current forces vUVWdot = vForces/mass - (VState.vPQR + 2.0*(Ti2b *vOmegaEarth)) * VState.vUVW; @@ -369,10 +368,10 @@ void FGPropagate::CalculateUVWdot(void) // Include Gravitation accel switch (gravType) { case gtStandard: - vGravAccel = Tl2b * FGColumnVector3( 0.0, 0.0, Inertial->GetGAccel(VehicleRadius) ); + vGravAccel = Tl2b * FGColumnVector3( 0.0, 0.0, FDMExec->GetInertial()->GetGAccel(VehicleRadius) ); break; case gtWGS84: - vGravAccel = Tec2b * Inertial->GetGravityJ2(VState.vLocation); + vGravAccel = Tec2b * FDMExec->GetInertial()->GetGravityJ2(VState.vLocation); break; } @@ -456,6 +455,55 @@ void FGPropagate::Integrate( FGQuaternion& Integrand, } } +//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +// Evaluates the rates (translation or rotation) that the friction forces have +// to resist to. This includes the external forces and moments as well as the +// relative movement between the aircraft and the ground. +// Erin Catto's paper (see ref [6]) only supports Euler integration scheme and +// this algorithm has been adapted to handle the multistep algorithms that +// JSBSim supports (i.e. Trapezoidal, Adams-Bashforth 2, 3 and 4). The capacity +// to handle the multistep integration schemes adds some complexity but it +// significantly helps stabilizing the friction forces. + +void FGPropagate::EvaluateRateToResistTo(FGColumnVector3& vdot, + const FGColumnVector3& Val, + const FGColumnVector3& ValDot, + const FGColumnVector3& LocalTerrainVal, + deque & dqValDot, + const double dt, + const eIntegrateType integration_type) +{ + switch(integration_type) { + case eAdamsBashforth4: + vdot = ValDot + Ti2b * (-59.*dqValDot[0]+37.*dqValDot[1]-9.*dqValDot[2])/55.; + if (dt > 0.) // Zeroes out the relative movement between aircraft and ground + vdot += 24.*(Val - Tec2b * LocalTerrainVal) / (55.*dt); + break; + case eAdamsBashforth3: + vdot = ValDot + Ti2b * (-16.*dqValDot[0]+5.*dqValDot[1])/23.; + if (dt > 0.) // Zeroes out the relative movement between aircraft and ground + vdot += 12.*(Val - Tec2b * LocalTerrainVal) / (23.*dt); + break; + case eAdamsBashforth2: + vdot = ValDot - Ti2b * dqValDot[0]/3.; + if (dt > 0.) // Zeroes out the relative movement between aircraft and ground + vdot += 2.*(Val - Tec2b * LocalTerrainVal) / (3.*dt); + break; + case eTrapezoidal: + vdot = ValDot + Ti2b * dqValDot[0]; + if (dt > 0.) // Zeroes out the relative movement between aircraft and ground + vdot += 2.*(Val - Tec2b * LocalTerrainVal) / dt; + break; + case eRectEuler: + vdot = ValDot; + if (dt > 0.) // Zeroes out the relative movement between aircraft and ground + vdot += (Val - Tec2b * LocalTerrainVal) / dt; + break; + case eNone: + break; + } +} + //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% // Resolves the contact forces just before integrating the EOM. // This routine is using Lagrange multipliers and the projected Gauss-Seidel @@ -471,61 +519,55 @@ void FGPropagate::Integrate( FGQuaternion& Integrand, void FGPropagate::ResolveFrictionForces(double dt) { - const double invMass = 1.0 / MassBalance->GetMass(); - const FGMatrix33& Jinv = MassBalance->GetJinv(); + const double invMass = 1.0 / FDMExec->GetMassBalance()->GetMass(); + const FGMatrix33& Jinv = FDMExec->GetMassBalance()->GetJinv(); vector JacF, JacM; + vector lambda, lambdaMin, lambdaMax; FGColumnVector3 vdot, wdot; FGColumnVector3 Fc, Mc; - int n = 0, i; + int n = 0; // Compiles data from the ground reactions to build up the jacobian matrix - for (MultiplierIterator it=MultiplierIterator(GroundReactions); *it; ++it, n++) { + for (MultiplierIterator it=MultiplierIterator(FDMExec->GetGroundReactions()); *it; ++it, n++) { JacF.push_back((*it)->ForceJacobian); JacM.push_back((*it)->MomentJacobian); + lambda.push_back((*it)->value); + lambdaMax.push_back((*it)->Max); + lambdaMin.push_back((*it)->Min); } // If no gears are in contact with the ground then return if (!n) return; vector a(n*n); // Will contain J*M^-1*J^T - vector eta(n); - vector lambda(n); - vector lambdaMin(n); - vector lambdaMax(n); - - // Initializes the Lagrange multipliers - i = 0; - for (MultiplierIterator it=MultiplierIterator(GroundReactions); *it; ++it, i++) { - lambda[i] = (*it)->value; - lambdaMax[i] = (*it)->Max; - lambdaMin[i] = (*it)->Min; - } - - vdot = vUVWdot; - wdot = vPQRdot; - - if (dt > 0.) { - // Instruct the algorithm to zero out the relative movement between the - // aircraft and the ground. - vdot += (VState.vUVW - Tec2b * LocalTerrainVelocity) / dt; - wdot += (VState.vPQR - Tec2b * LocalTerrainAngularVelocity) / dt; - } + vector rhs(n); // Assemble the linear system of equations - for (i=0; i < n; i++) { + for (int i=0; i < n; i++) { for (int j=0; j < i; j++) a[i*n+j] = a[j*n+i]; // Takes advantage of the symmetry of J^T*M^-1*J for (int j=i; j < n; j++) a[i*n+j] = DotProduct(JacF[i],invMass*JacF[j])+DotProduct(JacM[i],Jinv*JacM[j]); } + // Assemble the RHS member + + // Translation + EvaluateRateToResistTo(vdot, VState.vUVW, vUVWdot, LocalTerrainVelocity, + VState.dqUVWidot, dt, integrator_translational_rate); + + // Rotation + EvaluateRateToResistTo(wdot, VState.vPQR, vPQRdot, LocalTerrainAngularVelocity, + VState.dqPQRidot, dt, integrator_rotational_rate); + // Prepare the linear system for the Gauss-Seidel algorithm : - // divide every line of 'a' and eta by a[i,i]. This is in order to save - // a division computation at each iteration of Gauss-Seidel. - for (i=0; i < n; i++) { + // 1. Compute the right hand side member 'rhs' + // 2. Divide every line of 'a' and 'rhs' by a[i,i]. This is in order to save + // a division computation at each iteration of Gauss-Seidel. + for (int i=0; i < n; i++) { double d = 1.0 / a[i*n+i]; - eta[i] = -(DotProduct(JacF[i],vdot)+DotProduct(JacM[i],wdot))*d; + rhs[i] = -(DotProduct(JacF[i],vdot)+DotProduct(JacM[i],wdot))*d; for (int j=0; j < n; j++) a[i*n+j] *= d; } @@ -534,9 +576,9 @@ void FGPropagate::ResolveFrictionForces(double dt) for (int iter=0; iter < 50; iter++) { double norm = 0.; - for (i=0; i < n; i++) { + for (int i=0; i < n; i++) { double lambda0 = lambda[i]; - double dlambda = eta[i]; + double dlambda = rhs[i]; for (int j=0; j < n; j++) dlambda -= a[i*n+j]*lambda[j]; @@ -555,7 +597,7 @@ void FGPropagate::ResolveFrictionForces(double dt) Fc.InitMatrix(); Mc.InitMatrix(); - for (i=0; i< n; i++) { + for (int i=0; i< n; i++) { Fc += lambda[i]*JacF[i]; Mc += lambda[i]*JacM[i]; } @@ -567,33 +609,33 @@ void FGPropagate::ResolveFrictionForces(double dt) // Save the value of the Lagrange multipliers to accelerate the convergence // of the Gauss-Seidel algorithm at next iteration. - i = 0; - for (MultiplierIterator it=MultiplierIterator(GroundReactions); *it; ++it) + int i = 0; + for (MultiplierIterator it=MultiplierIterator(FDMExec->GetGroundReactions()); *it; ++it) (*it)->value = lambda[i++]; - GroundReactions->UpdateForcesAndMoments(); + FDMExec->GetGroundReactions()->UpdateForcesAndMoments(); } //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% void FGPropagate::UpdateLocationMatrices(void) { - Tl2ec = GetTl2ec(); // local to ECEF transform - Tec2l = Tl2ec.Transposed(); // ECEF to local frame transform - Ti2l = GetTi2l(); - Tl2i = Ti2l.Transposed(); + Tl2ec = VState.vLocation.GetTl2ec(); // local to ECEF transform + Tec2l = Tl2ec.Transposed(); // ECEF to local frame transform + Ti2l = VState.vLocation.GetTi2l(); // ECI to local frame transform + Tl2i = Ti2l.Transposed(); // local to ECI transform } //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% void FGPropagate::UpdateBodyMatrices(void) { - Ti2b = GetTi2b(); // ECI to body frame transform - Tb2i = Ti2b.Transposed(); // body to ECI frame transform - Tl2b = Ti2b*Tl2i; // local to body frame transform - Tb2l = Tl2b.Transposed(); // body to local frame transform - Tec2b = Tl2b * Tec2l; // ECEF to body frame transform - Tb2ec = Tec2b.Transposed(); // body to ECEF frame tranform + Ti2b = VState.qAttitudeECI.GetT(); // ECI to body frame transform + Tb2i = Ti2b.Transposed(); // body to ECI frame transform + Tl2b = Ti2b*Tl2i; // local to body frame transform + Tb2l = Tl2b.Transposed(); // body to local frame transform + Tec2b = Tl2b * Tec2l; // ECEF to body frame transform + Tb2ec = Tec2b.Transposed(); // body to ECEF frame tranform } //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @@ -610,7 +652,7 @@ void FGPropagate::SetInertialOrientation(FGQuaternion Qi) { void FGPropagate::SetInertialVelocity(FGColumnVector3 Vi) { VState.vInertialVelocity = Vi; CalculateUVW(); - vVel = GetTb2l() * VState.vUVW; + vVel = Tb2l * VState.vUVW; } //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @@ -633,13 +675,11 @@ void FGPropagate::InitializeDerivatives(void) CalculateInertialVelocity(); // Translational position derivative // Initialize past values deques - VState.dqPQRdot.clear(); VState.dqPQRidot.clear(); VState.dqUVWidot.clear(); VState.dqInertialVelocity.clear(); VState.dqQtrndot.clear(); for (int i=0; i<4; i++) { - VState.dqPQRdot.push_front(vPQRdot); VState.dqPQRidot.push_front(vPQRidot); VState.dqUVWidot.push_front(vUVWdot); VState.dqInertialVelocity.push_front(VState.vInertialVelocity); @@ -676,48 +716,57 @@ double FGPropagate::GetTerrainElevation(void) const return FDMExec->GetGroundCallback()->GetTerrainGeoCentRadius()-SeaLevelRadius; } -//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -//Todo: when should this be called - when should the new EPA be used to -// calculate the transformation matrix, so that the matrix is not a step -// ahead of the sim and the associated calculations? -const FGMatrix33& FGPropagate::GetTi2ec(void) -{ - return VState.vLocation.GetTi2ec(); -} - //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -const FGMatrix33& FGPropagate::GetTec2i(void) +double FGPropagate::GetDistanceAGL(void) const { - return VState.vLocation.GetTec2i(); + return VState.vLocation.GetRadius() - LocalTerrainRadius; } //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -void FGPropagate::SetAltitudeASL(double altASL) +void FGPropagate::SetVState(const VehicleState& vstate) { - VState.vLocation.SetRadius( altASL + SeaLevelRadius ); -} - -//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + VState.vLocation = vstate.vLocation; + VState.vLocation.SetEarthPositionAngle(FDMExec->GetInertial()->GetEarthPositionAngle()); + Ti2ec = VState.vLocation.GetTi2ec(); // useless ? + Tec2i = Ti2ec.Transposed(); + UpdateLocationMatrices(); + SetInertialOrientation(vstate.qAttitudeECI); + RecomputeLocalTerrainRadius(); + VehicleRadius = GetRadius(); + VState.vUVW = vstate.vUVW; + vVel = Tb2l * VState.vUVW; + VState.vPQR = vstate.vPQR; + VState.vPQRi = VState.vPQR + Ti2b * vOmegaEarth; + VState.vPQRi_i = Tb2i * VState.vPQRi; + VState.vInertialPosition = vstate.vInertialPosition; -double FGPropagate::GetLocalTerrainRadius(void) const -{ - return LocalTerrainRadius; + InitializeDerivatives(); } //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -double FGPropagate::GetDistanceAGL(void) const +void FGPropagate::UpdateVehicleState(void) { - return VState.vLocation.GetRadius() - LocalTerrainRadius; + RecomputeLocalTerrainRadius(); + VehicleRadius = GetRadius(); + VState.vInertialPosition = Tec2i * VState.vLocation; + UpdateLocationMatrices(); + UpdateBodyMatrices(); + vVel = Tb2l * VState.vUVW; + VState.qAttitudeLocal = Tl2b.GetQuaternion(); } //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -void FGPropagate::SetDistanceAGL(double tt) +void FGPropagate::SetLocation(const FGLocation& l) { - VState.vLocation.SetRadius( tt + LocalTerrainRadius ); + VState.vLocation = l; + VState.vLocation.SetEarthPositionAngle(FDMExec->GetInertial()->GetEarthPositionAngle()); + Ti2ec = VState.vLocation.GetTi2ec(); // useless ? + Tec2i = Ti2ec.Transposed(); + UpdateVehicleState(); } //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @@ -745,7 +794,7 @@ void FGPropagate::DumpState(void) cout << endl << " " << underon << "Velocity" << underoff << endl; cout << " ECI: " << VState.vInertialVelocity.Dump(", ") << " (x,y,z in ft/s)" << endl; - cout << " ECEF: " << (GetTb2ec() * VState.vUVW).Dump(", ") << " (x,y,z in ft/s)" << endl; + cout << " ECEF: " << (Tb2ec * VState.vUVW).Dump(", ") << " (x,y,z in ft/s)" << endl; cout << " Local: " << GetVel() << " (n,e,d in ft/sec)" << endl; cout << " Body: " << GetUVW() << " (u,v,w in ft/sec)" << endl; @@ -861,7 +910,7 @@ void FGPropagate::Debug(int from) << reset << endl; cout << endl; cout << highint << " Earth Position Angle (deg): " << setw(8) << setprecision(3) << reset - << Inertial->GetEarthPositionAngleDeg() << endl; + << FDMExec->GetInertial()->GetEarthPositionAngleDeg() << endl; cout << endl; cout << highint << " Body velocity (ft/sec): " << setw(8) << setprecision(3) << reset << VState.vUVW << endl; cout << highint << " Local velocity (ft/sec): " << setw(8) << setprecision(3) << reset << vVel << endl;