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flightgear/src/FDM/JSBSim/models/FGAuxiliary.cpp
ehofman 48cad71a70 Sync with JSBSim CVS again
2009-09-03 00:02:48 +02:00

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/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Module: FGAuxiliary.cpp
Author: Tony Peden, Jon Berndt
Date started: 01/26/99
Purpose: Calculates additional parameters needed by the visual system, etc.
Called by: FGSimExec
------------- Copyright (C) 1999 Jon S. Berndt (jon@jsbsim.org) -------------
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
details.
You should have received a copy of the GNU Lesser General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA 02111-1307, USA.
Further information about the GNU Lesser General Public License can also be found on
the world wide web at http://www.gnu.org.
FUNCTIONAL DESCRIPTION
--------------------------------------------------------------------------------
This class calculates various auxiliary parameters.
REFERENCES
Anderson, John D. "Introduction to Flight", 3rd Edition, McGraw-Hill, 1989
pgs. 112-126
HISTORY
--------------------------------------------------------------------------------
01/26/99 JSB Created
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
INCLUDES
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
#include "FGAuxiliary.h"
#include "FGAerodynamics.h"
#include "FGPropagate.h"
#include "FGAtmosphere.h"
#include <FGFDMExec.h>
#include "FGAircraft.h"
#include "FGInertial.h"
#include "FGExternalReactions.h"
#include "FGBuoyantForces.h"
#include "FGGroundReactions.h"
#include "FGPropulsion.h"
#include <input_output/FGPropertyManager.h>
namespace JSBSim {
static const char *IdSrc = "$Id$";
static const char *IdHdr = ID_AUXILIARY;
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
CLASS IMPLEMENTATION
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
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);
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
bool FGAuxiliary::InitModel(void)
{
if (!FGModel::InitModel()) return false;
vcas = veas = pt = tat = 0;
psl = rhosl = 1;
qbar = 0;
qbarUW = 0.0;
qbarUV = 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;
vPilotAccel.InitMatrix();
vPilotAccelN.InitMatrix();
vToEyePt.InitMatrix();
vAeroPQR.InitMatrix();
vEulerRates.InitMatrix();
return true;
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
FGAuxiliary::~FGAuxiliary()
{
Debug(1);
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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;
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
//
// A positive headwind is blowing with you, a negative headwind is blowing against you.
// psi is the direction the wind is blowing *towards*.
double FGAuxiliary::GetHeadWind(void) const
{
double psiw,vw;
psiw = Atmosphere->GetWindPsi();
vw = Atmosphere->GetTotalWindNED().Magnitude();
return vw*cos(psiw - Propagate->GetEuler(ePsi));
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
//
// A positive crosswind is blowing towards the right (from teh perspective of the
// pilot). A negative crosswind is blowing towards the -Y direction (left).
// psi is the direction the wind is blowing *towards*.
double FGAuxiliary::GetCrossWind(void) const
{
double psiw,vw;
psiw = Atmosphere->GetWindPsi();
vw = Atmosphere->GetTotalWindNED().Magnitude();
return vw*sin(psiw - Propagate->GetEuler(ePsi));
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
void FGAuxiliary::bind(void)
{
typedef double (FGAuxiliary::*PMF)(int) const;
typedef double (FGAuxiliary::*PF)(void) const;
PropertyManager->Tie("propulsion/tat-r", this, &FGAuxiliary::GetTotalTemperature);
PropertyManager->Tie("propulsion/tat-c", this, &FGAuxiliary::GetTAT_C);
PropertyManager->Tie("propulsion/pt-lbs_sqft", this, &FGAuxiliary::GetTotalPressure);
PropertyManager->Tie("velocities/vc-fps", this, &FGAuxiliary::GetVcalibratedFPS);
PropertyManager->Tie("velocities/vc-kts", this, &FGAuxiliary::GetVcalibratedKTS);
PropertyManager->Tie("velocities/ve-fps", this, &FGAuxiliary::GetVequivalentFPS);
PropertyManager->Tie("velocities/ve-kts", this, &FGAuxiliary::GetVequivalentKTS);
PropertyManager->Tie("velocities/machU", this, &FGAuxiliary::GetMachU);
PropertyManager->Tie("velocities/p-aero-rad_sec", this, eX, (PMF)&FGAuxiliary::GetAeroPQR);
PropertyManager->Tie("velocities/q-aero-rad_sec", this, eY, (PMF)&FGAuxiliary::GetAeroPQR);
PropertyManager->Tie("velocities/r-aero-rad_sec", this, eZ, (PMF)&FGAuxiliary::GetAeroPQR);
PropertyManager->Tie("velocities/phidot-rad_sec", this, ePhi, (PMF)&FGAuxiliary::GetEulerRates);
PropertyManager->Tie("velocities/thetadot-rad_sec", this, eTht, (PMF)&FGAuxiliary::GetEulerRates);
PropertyManager->Tie("velocities/psidot-rad_sec", this, ePsi, (PMF)&FGAuxiliary::GetEulerRates);
PropertyManager->Tie("velocities/u-aero-fps", this, eU, (PMF)&FGAuxiliary::GetAeroUVW);
PropertyManager->Tie("velocities/v-aero-fps", this, eV, (PMF)&FGAuxiliary::GetAeroUVW);
PropertyManager->Tie("velocities/w-aero-fps", this, eW, (PMF)&FGAuxiliary::GetAeroUVW);
PropertyManager->Tie("velocities/vt-fps", this, &FGAuxiliary::GetVt, &FGAuxiliary::SetVt, true);
PropertyManager->Tie("velocities/mach", this, &FGAuxiliary::GetMach, &FGAuxiliary::SetMach, true);
PropertyManager->Tie("velocities/vg-fps", this, &FGAuxiliary::GetVground);
PropertyManager->Tie("accelerations/a-pilot-x-ft_sec2", this, eX, (PMF)&FGAuxiliary::GetPilotAccel);
PropertyManager->Tie("accelerations/a-pilot-y-ft_sec2", this, eY, (PMF)&FGAuxiliary::GetPilotAccel);
PropertyManager->Tie("accelerations/a-pilot-z-ft_sec2", this, eZ, (PMF)&FGAuxiliary::GetPilotAccel);
PropertyManager->Tie("accelerations/n-pilot-x-norm", this, eX, (PMF)&FGAuxiliary::GetNpilot);
PropertyManager->Tie("accelerations/n-pilot-y-norm", this, eY, (PMF)&FGAuxiliary::GetNpilot);
PropertyManager->Tie("accelerations/n-pilot-z-norm", this, eZ, (PMF)&FGAuxiliary::GetNpilot);
PropertyManager->Tie("accelerations/Nz", this, &FGAuxiliary::GetNz);
/* PropertyManager->Tie("atmosphere/headwind-fps", this, &FGAuxiliary::GetHeadWind, true);
PropertyManager->Tie("atmosphere/crosswind-fps", this, &FGAuxiliary::GetCrossWind, true); */
PropertyManager->Tie("aero/alpha-rad", this, (PF)&FGAuxiliary::Getalpha, &FGAuxiliary::Setalpha, true);
PropertyManager->Tie("aero/beta-rad", this, (PF)&FGAuxiliary::Getbeta, &FGAuxiliary::Setbeta, true);
PropertyManager->Tie("aero/mag-beta-rad", this, (PF)&FGAuxiliary::GetMagBeta);
PropertyManager->Tie("aero/alpha-deg", this, inDegrees, (PMF)&FGAuxiliary::Getalpha);
PropertyManager->Tie("aero/beta-deg", this, inDegrees, (PMF)&FGAuxiliary::Getbeta);
PropertyManager->Tie("aero/mag-beta-deg", this, inDegrees, (PMF)&FGAuxiliary::GetMagBeta);
PropertyManager->Tie("aero/Re", this, &FGAuxiliary::GetReynoldsNumber);
PropertyManager->Tie("aero/qbar-psf", this, &FGAuxiliary::Getqbar, &FGAuxiliary::Setqbar, true);
PropertyManager->Tie("aero/qbarUW-psf", this, &FGAuxiliary::GetqbarUW, &FGAuxiliary::SetqbarUW, true);
PropertyManager->Tie("aero/qbarUV-psf", this, &FGAuxiliary::GetqbarUV, &FGAuxiliary::SetqbarUV, true);
PropertyManager->Tie("aero/alphadot-rad_sec", this, (PF)&FGAuxiliary::Getadot, &FGAuxiliary::Setadot, true);
PropertyManager->Tie("aero/betadot-rad_sec", this, (PF)&FGAuxiliary::Getbdot, &FGAuxiliary::Setbdot, true);
PropertyManager->Tie("aero/alphadot-deg_sec", this, inDegrees, (PMF)&FGAuxiliary::Getadot);
PropertyManager->Tie("aero/betadot-deg_sec", this, inDegrees, (PMF)&FGAuxiliary::Getbdot);
PropertyManager->Tie("aero/h_b-cg-ft", this, &FGAuxiliary::GetHOverBCG);
PropertyManager->Tie("aero/h_b-mac-ft", this, &FGAuxiliary::GetHOverBMAC);
PropertyManager->Tie("flight-path/gamma-rad", this, &FGAuxiliary::GetGamma, &FGAuxiliary::SetGamma);
PropertyManager->Tie("flight-path/psi-gt-rad", this, &FGAuxiliary::GetGroundTrack);
PropertyManager->Tie("position/distance-from-start-lon-mt", this, &FGAuxiliary::GetLongitudeRelativePosition);
PropertyManager->Tie("position/distance-from-start-lat-mt", this, &FGAuxiliary::GetLatitudeRelativePosition);
PropertyManager->Tie("position/distance-from-start-mag-mt", this, &FGAuxiliary::GetDistanceRelativePosition);
PropertyManager->Tie("position/vrp-gc-latitude_deg", &vLocationVRP, &FGLocation::GetLatitudeDeg);
PropertyManager->Tie("position/vrp-longitude_deg", &vLocationVRP, &FGLocation::GetLongitudeDeg);
PropertyManager->Tie("position/vrp-radius-ft", &vLocationVRP, &FGLocation::GetRadius);
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
void FGAuxiliary::CalculateRelativePosition(void)
{
const double earth_radius_mt = Inertial->GetRefRadius()*fttom;
lat_relative_position=(FDMExec->GetPropagate()->GetLatitude() - FDMExec->GetIC()->GetLatitudeDegIC() *degtorad)*earth_radius_mt;
lon_relative_position=(FDMExec->GetPropagate()->GetLongitude() - FDMExec->GetIC()->GetLongitudeDegIC()*degtorad)*earth_radius_mt;
relative_position = sqrt(lat_relative_position*lat_relative_position + lon_relative_position*lon_relative_position);
};
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
// The bitmasked value choices are as follows:
// unset: In this case (the default) JSBSim would only print
// out the normally expected messages, essentially echoing
// the config files as they are read. If the environment
// variable is not set, debug_lvl is set to 1 internally
// 0: This requests JSBSim not to output any messages
// whatsoever.
// 1: This value explicity requests the normal JSBSim
// startup messages
// 2: This value asks for a message to be printed out when
// a class is instantiated
// 4: When this value is set, a message is displayed when a
// FGModel object executes its Run() method
// 8: When this value is set, various runtime state variables
// are printed out periodically
// 16: When set various parameters are sanity checked and
// a message is printed out when they go out of bounds
void FGAuxiliary::Debug(int from)
{
if (debug_lvl <= 0) return;
if (debug_lvl & 1) { // Standard console startup message output
if (from == 0) { // Constructor
}
}
if (debug_lvl & 2 ) { // Instantiation/Destruction notification
if (from == 0) cout << "Instantiated: FGAuxiliary" << endl;
if (from == 1) cout << "Destroyed: FGAuxiliary" << endl;
}
if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
}
if (debug_lvl & 8 ) { // Runtime state variables
}
if (debug_lvl & 16) { // Sanity checking
if (Mach > 100 || Mach < 0.00)
cout << "FGPropagate::Mach is out of bounds: " << Mach << endl;
if (qbar > 1e6 || qbar < 0.00)
cout << "FGPropagate::qbar is out of bounds: " << qbar << endl;
}
if (debug_lvl & 64) {
if (from == 0) { // Constructor
cout << IdSrc << endl;
cout << IdHdr << endl;
}
}
}
} // namespace JSBSim
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