bool FGAuxiliary::InitModel(void)
{
if (!FGModel::InitModel()) return false;
pt = in.Pressure;
tat = in.Temperature;
tatc = RankineToCelsius(tat);
vcas = veas = 0.0;
qbar = qbarUW = qbarUV = 0.0;
Mach = MachU = 0.0;
alpha = beta = 0.0;
adot = bdot = 0.0;
gamma = Vt = Vground = 0.0;
psigt = 0.0;
day_of_year = 1;
seconds_in_day = 0.0;
hoverbmac = hoverbcg = 0.0;
Re = 0.0;
Nz = Ny = 0.0;
lon_relative_position = lat_relative_position = relative_position = 0.0;
vPilotAccel.InitMatrix();
vPilotAccelN.InitMatrix();
vAeroUVW.InitMatrix();
vAeroPQR.InitMatrix();
vMachUVW.InitMatrix();
vEuler.InitMatrix();
vEulerRates.InitMatrix();
return true;
}
FGAuxiliary::FGAuxiliary(FGFDMExec* fdmex) : FGModel(fdmex)
{
Name = "FGAuxiliary";
pt = 1.0;
tat = 1.0;
tatc = RankineToCelsius(tat);
vcas = veas = 0.0;
qbar = qbarUW = qbarUV = 0.0;
Mach = MachU = 0.0;
alpha = beta = 0.0;
adot = bdot = 0.0;
gamma = Vt = Vground = 0.0;
psigt = 0.0;
day_of_year = 1;
seconds_in_day = 0.0;
hoverbmac = hoverbcg = 0.0;
Re = 0.0;
Nz = Ny = 0.0;
lon_relative_position = lat_relative_position = relative_position = 0.0;
vPilotAccel.InitMatrix();
vPilotAccelN.InitMatrix();
vAeroUVW.InitMatrix();
vAeroPQR.InitMatrix();
vMachUVW.InitMatrix();
vEuler.InitMatrix();
vEulerRates.InitMatrix();
bind();
Debug(0);
}
FGAuxiliary::FGAuxiliary(FGFDMExec* fdmex) : FGModel(fdmex)
{
Name = "FGAuxiliary";
vcas = veas = pt = tat = 0;
psl = rhosl = 1;
qbar = 0;
qbarUW = 0.0;
qbarUV = 0.0;
Re = 0.0;
Mach = 0.0;
alpha = beta = 0.0;
adot = bdot = 0.0;
gamma = Vt = Vground = 0.0;
psigt = 0.0;
day_of_year = 1;
seconds_in_day = 0.0;
hoverbmac = hoverbcg = 0.0;
tatc = RankineToCelsius(tat);
vPilotAccel.InitMatrix();
vPilotAccelN.InitMatrix();
vToEyePt.InitMatrix();
vAeroPQR.InitMatrix();
vEulerRates.InitMatrix();
bind();
Debug(0);
}
//=========================================================================
// Update Temperature, pressure and density from altitude
// NOTE: Temperature is adjusted with the local conditions
// if local condition say 20°C, then temperature is adusted
// by the delta (20 - 15) because 15°C is the standard temperature
// at sea level; We just make a (certainly) wrong supposition by
// saying that temperature is 5° higgher at all altitude
//=========================================================================
void CAtmosphereModelJSBSim::TimeSlice(float dt,double altitude)
{ //---Compute temperature and pressure -----------------------
// slot.U = slope
// slot.V = Temperature in Rankine
// slot.W = pressure (psf)
C3valSlot *slot = stdATMOS.Getfloor(altitude);
float slp = slot->GetU();
float rfT = slot->GetV();
float rfP = slot->GetW();
float da = altitude - slot->GetX();
float tp = 0;
float pr = 0;
float dn = 0;
//---Compute new targets ---------------------
if (0 == slp)
{ tp = rfT;
pr = rfP * exp(-pInertial->SLgravity()/(rfT*Reng)* da);
dn = pr/ (Reng*tp);
}
else
{ tp = rfT + (slp * da);
pr = rfP * pow(float(tp/rfT),float(-pInertial->SLgravity()/(slp*Reng)));
dn = pr/(Reng*tp);
}
//--- Get final values -----------------------------------------------
tempR = tVAL.TimeSlice(dt);
presS = pVAL.TimeSlice(dt);
densD = dVAL.TimeSlice(dt);
//--- Set Target value -----------------------------------------------
tVAL.Set(tp);
pVAL.Set(pr);
dVAL.Set(dn);
//---Update temperature to various units -----------------------------
tempC = RankineToCelsius(tempR) + dtaTC;
tempF = CelsiusToFahrenheit(tempC);
//---Update pressure to various units --------------------------------
presS += dtaPS; // Add local deviation
presH = presS * PSF_TO_INHG;
presB = presS * PFS_TO_HPA;
//--- Update sound speed ---------------------------------------------
soundspeed = sqrt(SHRatio*Reng*(tempR));
//--------------------------------------------------------------------
// test others density
//densD *= 10.0;
//cout << "Atmosphere: h=" << altitude << " rho= " << densD << endl;
// #ifdef _DEBUG
// FILE *fp_debug;
// if(!(fp_debug = fopen("__DDEBUG_atmosphere.txt", "a")) == NULL)
// {
// int test = 0;
// fprintf(fp_debug, "TPD = %f %f %f\n", tempR, presS, densD);
// fprintf(fp_debug, "TPD = %f %f %f\n",
// RankineToCelsius (tempR),
// presS * PSF_TO_INHG,
// densD);
// fclose(fp_debug);
// }
// #endif
}
//=========================================================================
// Update Temperature, pressure and density from altitude
// NOTE: Temperature is adjusted with the local conditions
// if local condition say 20°C, then temperature is adusted
// by the delta (20 - 15) because 15°C is the standard temperature
// at sea level; We just make a (certainly) wrong supposition by
// saying that temperature is 5° higgher at all altitude
//=========================================================================
int CAtmosphereModelJSBSim::TimeSlice(float dt,U_INT frame)
{ double altitude = globals->geop.alt;
//---Compute temperature and pressure -----------------------
C3valSlot *slot = stdATMOS.Getfloor(altitude);
float slp = slot->GetU();
float rfT = slot->GetV();
float rfP = slot->GetW();
float da = altitude - slot->GetX();
float tp = 0;
float pr = 0;
float dn = 0;
//---Compute new targets ---------------------
if (0 == slp)
{ tp = rfT;
pr = rfP * exp(-pInertial->SLgravity()/(rfT*Reng)* da);
dn = pr/ (Reng*tp);
}
else
{ tp = rfT + (slp * da);
pr = rfP * pow(float(tp/rfT),float(-pInertial->SLgravity()/(slp*Reng)));
dn = pr/(Reng*tp);
}
//--- Get final values -----------------------------------------------
tempR = tVAL.TimeSlice(dt);
presS = pVAL.TimeSlice(dt);
densD = dVAL.TimeSlice(dt);
//--- Set Target value -----------------------------------------------
tVAL.Set(tp);
pVAL.Set(pr);
dVAL.Set(dn);
//---Update temperature to various units -----------------------------
tempC = RankineToCelsius(tempR) + dtaTC;
tempF = CelsiusToFahrenheit(tempC);
//---Update pressure to various units --------------------------------
presS += dtaPS; // Add local deviation
presH = presS * PSF_TO_INHG;
presB = presS * PFS_TO_HPA;
//--- Update sound speed ---------------------------------------------
soundspeed = sqrt(SHRatio*Reng*(tempR));
return 1;
}
bool FGAuxiliary::Run(bool Holding)
{
double A,B,D;
if (FGModel::Run(Holding)) return true; // return true if error returned from base class
if (Holding) return false;
// Rotation
vEulerRates(eTht) = in.vPQR(eQ)*in.CosPhi - in.vPQR(eR)*in.SinPhi;
if (in.CosTht != 0.0) {
vEulerRates(ePsi) = (in.vPQR(eQ)*in.SinPhi + in.vPQR(eR)*in.CosPhi)/in.CosTht;
vEulerRates(ePhi) = in.vPQR(eP) + vEulerRates(ePsi)*in.SinTht;
}
// Combine the wind speed with aircraft speed to obtain wind relative speed
vAeroPQR = in.vPQR - in.TurbPQR;
vAeroUVW = in.vUVW - in.Tl2b * in.TotalWindNED;
Vt = vAeroUVW.Magnitude();
alpha = beta = adot = bdot = 0;
double AeroU2 = vAeroUVW(eU)*vAeroUVW(eU);
double AeroV2 = vAeroUVW(eV)*vAeroUVW(eV);
double AeroW2 = vAeroUVW(eW)*vAeroUVW(eW);
double mUW = AeroU2 + AeroW2;
double Vtdot = (vAeroUVW(eU)*in.vUVWdot(eU) + vAeroUVW(eV)*in.vUVWdot(eV) + vAeroUVW(eW)*in.vUVWdot(eW))/Vt;
double Vt2 = Vt*Vt;
if ( Vt > 0.001 ) {
if (vAeroUVW(eW) != 0.0)
alpha = AeroU2 > 0.0 ? atan2(vAeroUVW(eW), vAeroUVW(eU)) : 0.0;
if (vAeroUVW(eV) != 0.0)
beta = mUW > 0.0 ? atan2(vAeroUVW(eV), sqrt(mUW)) : 0.0;
//double signU=1;
//if (vAeroUVW(eU) < 0.0) signU=-1;
if ( mUW >= 0.001 ) {
adot = (vAeroUVW(eU)*in.vUVWdot(eW) - vAeroUVW(eW)*in.vUVWdot(eU))/mUW;
// bdot = (signU*mUW*in.vUVWdot(eV)
// - vAeroUVW(eV)*(vAeroUVW(eU)*in.vUVWdot(eU) + vAeroUVW(eW)*in.vUVWdot(eW)))/(Vt2*sqrt(mUW));
bdot = (in.vUVWdot(eV)*Vt - vAeroUVW(eV)*Vtdot)/(Vt*sqrt(mUW));
}
}
UpdateWindMatrices();
Re = Vt * in.Wingchord / in.KinematicViscosity;
double densityD2 = 0.5*in.Density;
qbar = densityD2 * Vt2;
qbarUW = densityD2 * (mUW);
qbarUV = densityD2 * (AeroU2 + AeroV2);
Mach = Vt / in.SoundSpeed;
MachU = vMachUVW(eU) = vAeroUVW(eU) / in.SoundSpeed;
vMachUVW(eV) = vAeroUVW(eV) / in.SoundSpeed;
vMachUVW(eW) = vAeroUVW(eW) / in.SoundSpeed;
double MachU2 = MachU * MachU;
// Position
Vground = sqrt( in.vVel(eNorth)*in.vVel(eNorth) + in.vVel(eEast)*in.vVel(eEast) );
psigt = atan2(in.vVel(eEast), in.vVel(eNorth));
if (psigt < 0.0) psigt += 2*M_PI;
gamma = atan2(-in.vVel(eDown), Vground);
tat = in.Temperature*(1 + 0.2*Mach*Mach); // Total Temperature, isentropic flow
tatc = RankineToCelsius(tat);
if (MachU < 1) { // Calculate total pressure assuming isentropic flow
pt = in.Pressure*pow((1 + 0.2*MachU2),3.5);
} else {
// Use Rayleigh pitot tube formula for normal shock in front of pitot tube
B = 5.76 * MachU2 / (5.6*MachU2 - 0.8);
D = (2.8 * MachU2 - 0.4) * 0.4167;
pt = in.Pressure*pow(B,3.5)*D;
}
A = pow(((pt-in.Pressure)/in.PressureSL + 1),0.28571);
if (abs(MachU) > 0.0) {
vcas = sqrt(7 * in.PressureSL / in.DensitySL * (A-1));
veas = sqrt(2 * qbar / in.DensitySL);
vtrue = 1116.43559 * Mach * sqrt(in.Temperature / 518.67);
} else {
vcas = veas = vtrue = 0.0;
}
vPilotAccel.InitMatrix();
vNcg = in.vBodyAccel/in.SLGravity;
// Nz is Acceleration in "g's", along normal axis (-Z body axis)
Nz = -vNcg(eZ);
Ny = vNcg(eY);
vPilotAccel = in.vBodyAccel + in.vPQRdot * in.ToEyePt;
vPilotAccel += in.vPQR * (in.vPQR * in.ToEyePt);
vNwcg = mTb2w * vNcg;
vNwcg(eZ) = 1.0 - vNwcg(eZ);
vPilotAccelN = vPilotAccel / in.SLGravity;
// VRP computation
vLocationVRP = in.vLocation.LocalToLocation( in.Tb2l * in.VRPBody );
// Recompute some derived values now that we know the dependent parameters values ...
hoverbcg = in.DistanceAGL / in.Wingspan;
FGColumnVector3 vMac = in.Tb2l * in.RPBody;
hoverbmac = (in.DistanceAGL + vMac(3)) / in.Wingspan;
// When all models are executed calculate the distance from the initial point.
CalculateRelativePosition();
return false;
}
bool FGAuxiliary::Run()
{
double A,B,D;
if (FGModel::Run()) return true; // return true if error returned from base class
if (FDMExec->Holding()) return false;
const FGColumnVector3& vPQR = Propagate->GetPQR();
const FGColumnVector3& vUVW = Propagate->GetUVW();
const FGColumnVector3& vUVWdot = Propagate->GetUVWdot();
const FGColumnVector3& vVel = Propagate->GetVel();
p = Atmosphere->GetPressure();
rhosl = Atmosphere->GetDensitySL();
psl = Atmosphere->GetPressureSL();
sat = Atmosphere->GetTemperature();
// Rotation
double cTht = Propagate->GetCosEuler(eTht);
double sTht = Propagate->GetSinEuler(eTht);
double cPhi = Propagate->GetCosEuler(ePhi);
double sPhi = Propagate->GetSinEuler(ePhi);
vEulerRates(eTht) = vPQR(eQ)*cPhi - vPQR(eR)*sPhi;
if (cTht != 0.0) {
vEulerRates(ePsi) = (vPQR(eQ)*sPhi + vPQR(eR)*cPhi)/cTht;
vEulerRates(ePhi) = vPQR(eP) + vEulerRates(ePsi)*sTht;
}
// 12/16/2005, JSB: For ground handling purposes, at this time, let's ramp
// in the effects of wind from 10 fps to 30 fps when there is weight on the
// landing gear wheels.
if (GroundReactions->GetWOW() && vUVW(eU) < 10) {
vAeroPQR = vPQR;
vAeroUVW = vUVW;
} else if (GroundReactions->GetWOW() && vUVW(eU) < 30) {
double factor = (vUVW(eU) - 10.0)/20.0;
vAeroPQR = vPQR - factor*Atmosphere->GetTurbPQR();
vAeroUVW = vUVW - factor*Propagate->GetTl2b()*Atmosphere->GetTotalWindNED();
} else {
FGColumnVector3 wind = Propagate->GetTl2b()*Atmosphere->GetTotalWindNED();
vAeroPQR = vPQR - Atmosphere->GetTurbPQR();
vAeroUVW = vUVW - wind;
}
Vt = vAeroUVW.Magnitude();
if ( Vt > 0.05) {
if (vAeroUVW(eW) != 0.0)
alpha = vAeroUVW(eU)*vAeroUVW(eU) > 0.0 ? atan2(vAeroUVW(eW), vAeroUVW(eU)) : 0.0;
if (vAeroUVW(eV) != 0.0)
beta = vAeroUVW(eU)*vAeroUVW(eU)+vAeroUVW(eW)*vAeroUVW(eW) > 0.0 ? atan2(vAeroUVW(eV),
sqrt(vAeroUVW(eU)*vAeroUVW(eU) + vAeroUVW(eW)*vAeroUVW(eW))) : 0.0;
double mUW = (vAeroUVW(eU)*vAeroUVW(eU) + vAeroUVW(eW)*vAeroUVW(eW));
double signU=1;
if (vAeroUVW(eU) != 0.0)
signU = vAeroUVW(eU)/fabs(vAeroUVW(eU));
if ( (mUW == 0.0) || (Vt == 0.0) ) {
adot = 0.0;
bdot = 0.0;
} else {
adot = (vAeroUVW(eU)*vUVWdot(eW) - vAeroUVW(eW)*vUVWdot(eU))/mUW;
bdot = (signU*mUW*vUVWdot(eV) - vAeroUVW(eV)*(vAeroUVW(eU)*vUVWdot(eU)
+ vAeroUVW(eW)*vUVWdot(eW)))/(Vt*Vt*sqrt(mUW));
}
} else {
alpha = beta = adot = bdot = 0;
}
Re = Vt * Aircraft->Getcbar() / Atmosphere->GetKinematicViscosity();
qbar = 0.5*Atmosphere->GetDensity()*Vt*Vt;
qbarUW = 0.5*Atmosphere->GetDensity()*(vAeroUVW(eU)*vAeroUVW(eU) + vAeroUVW(eW)*vAeroUVW(eW));
qbarUV = 0.5*Atmosphere->GetDensity()*(vAeroUVW(eU)*vAeroUVW(eU) + vAeroUVW(eV)*vAeroUVW(eV));
Mach = Vt / Atmosphere->GetSoundSpeed();
MachU = vMachUVW(eU) = vAeroUVW(eU) / Atmosphere->GetSoundSpeed();
vMachUVW(eV) = vAeroUVW(eV) / Atmosphere->GetSoundSpeed();
vMachUVW(eW) = vAeroUVW(eW) / Atmosphere->GetSoundSpeed();
// Position
Vground = sqrt( vVel(eNorth)*vVel(eNorth) + vVel(eEast)*vVel(eEast) );
psigt = atan2(vVel(eEast), vVel(eNorth));
if (psigt < 0.0) psigt += 2*M_PI;
gamma = atan2(-vVel(eDown), Vground);
tat = sat*(1 + 0.2*Mach*Mach); // Total Temperature, isentropic flow
tatc = RankineToCelsius(tat);
if (MachU < 1) { // Calculate total pressure assuming isentropic flow
pt = p*pow((1 + 0.2*MachU*MachU),3.5);
} else {
// Use Rayleigh pitot tube formula for normal shock in front of pitot tube
B = 5.76*MachU*MachU/(5.6*MachU*MachU - 0.8);
D = (2.8*MachU*MachU-0.4)*0.4167;
pt = p*pow(B,3.5)*D;
}
A = pow(((pt-p)/psl+1),0.28571);
if (MachU > 0.0) {
vcas = sqrt(7*psl/rhosl*(A-1));
veas = sqrt(2*qbar/rhosl);
} else {
vcas = veas = 0.0;
}
vPilotAccel.InitMatrix();
if ( Vt > 1.0 ) {
vAircraftAccel = Aerodynamics->GetForces()
+ Propulsion->GetForces()
+ GroundReactions->GetForces()
+ ExternalReactions->GetForces()
+ BuoyantForces->GetForces();
vAircraftAccel /= MassBalance->GetMass();
// Nz is Acceleration in "g's", along normal axis (-Z body axis)
Nz = -vAircraftAccel(eZ)/Inertial->gravity();
vToEyePt = MassBalance->StructuralToBody(Aircraft->GetXYZep());
vPilotAccel = vAircraftAccel + Propagate->GetPQRdot() * vToEyePt;
vPilotAccel += vPQR * (vPQR * vToEyePt);
} else {
// The line below handles low velocity (and on-ground) cases, basically
// representing the opposite of the force that the landing gear would
// exert on the ground (which is just the total weight). This eliminates
// any jitter that could be introduced by the landing gear. Theoretically,
// this branch could be eliminated, with a penalty of having a short
// transient at startup (lasting only a fraction of a second).
vPilotAccel = Propagate->GetTl2b() * FGColumnVector3( 0.0, 0.0, -Inertial->gravity() );
Nz = -vPilotAccel(eZ)/Inertial->gravity();
}
vPilotAccelN = vPilotAccel/Inertial->gravity();
// VRP computation
const FGLocation& vLocation = Propagate->GetLocation();
FGColumnVector3 vrpStructural = Aircraft->GetXYZvrp();
FGColumnVector3 vrpBody = MassBalance->StructuralToBody( vrpStructural );
FGColumnVector3 vrpLocal = Propagate->GetTb2l() * vrpBody;
vLocationVRP = vLocation.LocalToLocation( vrpLocal );
// Recompute some derived values now that we know the dependent parameters values ...
hoverbcg = Propagate->GetDistanceAGL() / Aircraft->GetWingSpan();
FGColumnVector3 vMac = Propagate->GetTb2l()*MassBalance->StructuralToBody(Aircraft->GetXYZrp());
hoverbmac = (Propagate->GetDistanceAGL() + vMac(3)) / Aircraft->GetWingSpan();
// when all model are executed,
// please calculate the distance from the initial point
CalculateRelativePosition();
return false;
}
