/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Module: FGAuxiliary.cpp
- Author: Jon Berndt
+ Author: Tony Peden, Jon Berndt
Date started: 01/26/99
Purpose: Calculates additional parameters needed by the visual system, etc.
Called by: FGSimExec
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
details.
-
+
You should have received a copy of the GNU 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 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 "FGTranslation.h"
#include "FGRotation.h"
#include "FGAtmosphere.h"
#include "FGAircraft.h"
#include "FGPosition.h"
#include "FGOutput.h"
-#include "FGMatrix.h"
+#include "FGInertial.h"
+#include "FGMatrix33.h"
+#include "FGColumnVector3.h"
+#include "FGColumnVector4.h"
+#include "FGPropertyManager.h"
-static const char *IdSrc = "$Header$";
+namespace JSBSim {
+
+static const char *IdSrc = "$Id$";
static const char *IdHdr = ID_AUXILIARY;
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
CLASS IMPLEMENTATION
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
-FGAuxiliary::FGAuxiliary(FGFDMExec* fdmex) : FGModel(fdmex) {
+
+FGAuxiliary::FGAuxiliary(FGFDMExec* fdmex) : FGModel(fdmex)
+{
Name = "FGAuxiliary";
- vcas = veas = mach = qbar = pt = 0;
+ vcas = veas = mach = qbar = pt = tat = 0;
psl = rhosl = 1;
earthPosAngle = 0.0;
+
+ vPilotAccelN.InitMatrix();
+
+ bind();
+
+ Debug(0);
}
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-FGAuxiliary::~FGAuxiliary() {}
-
+FGAuxiliary::~FGAuxiliary()
+{
+ unbind();
+ Debug(1);
+}
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-bool FGAuxiliary::Run() {
- float A,B,D;
+bool FGAuxiliary::Run()
+{
+ double A,B,D;
if (!FGModel::Run()) {
GetState();
- if(mach < 1) //calculate total pressure assuming isentropic flow
- pt=p*pow((1 + 0.2*mach*mach),3.5);
- else {
+
+ //calculate total temperature assuming isentropic flow
+ tat=sat*(1 + 0.2*mach*mach);
+ tatc=RankineToCelsius(tat);
+
+ if (mach < 1) { //calculate total pressure assuming isentropic flow
+ pt = p*pow((1 + 0.2*machU*machU),3.5);
+ } else {
// shock in front of pitot tube, we'll assume its normal and use
// the Rayleigh Pitot Tube Formula, i.e. the ratio of total
// pressure behind the shock to the static pressure in front
- B = 5.76*mach*mach/(5.6*mach*mach - 0.8);
+ B = 5.76*machU*machU/(5.6*machU*machU - 0.8);
// The denominator above is zero for Mach ~ 0.38, for which
// we'll never be here, so we're safe
- D = (2.8*mach*mach-0.4)*0.4167;
+ D = (2.8*machU*machU-0.4)*0.4167;
pt = p*pow(B,3.5)*D;
}
A = pow(((pt-p)/psl+1),0.28571);
- vcas = sqrt(7*psl/rhosl*(A-1));
- veas = sqrt(2*qbar/rhosl);
-
- vPilotAccel = Translation->GetUVWdot() + Aircraft->GetXYZep() * Rotation->GetPQRdot();
-
-
+ if (machU > 0.0) {
+ vcas = sqrt(7*psl/rhosl*(A-1));
+ veas = sqrt(2*qbar/rhosl);
+ } else {
+ vcas = veas = 0.0;
+ }
+
+ // Pilot sensed accelerations are calculated here. This is used
+ // for the coordinated turn ball instrument. Motion base platforms sometimes
+ // use the derivative of pilot sensed accelerations as the driving parameter,
+ // rather than straight accelerations.
+ //
+ // The theory behind pilot-sensed calculations is presented:
+ //
+ // For purposes of discussion and calculation, assume for a minute that the
+ // pilot is in space and motionless in inertial space. She will feel
+ // no accelerations. If the aircraft begins to accelerate along any axis or
+ // axes (without rotating), the pilot will sense those accelerations. If
+ // any rotational moment is applied, the pilot will sense an acceleration
+ // due to that motion in the amount:
+ //
+ // [wdot X R] + [w X (w X R)]
+ // Term I Term II
+ //
+ // where:
+ //
+ // wdot = omegadot, the rotational acceleration rate vector
+ // w = omega, the rotational rate vector
+ // R = the vector from the aircraft CG to the pilot eyepoint
+ //
+ // The sum total of these two terms plus the acceleration of the aircraft
+ // body axis gives the acceleration the pilot senses in inertial space.
+ // In the presence of a large body such as a planet, a gravity field also
+ // provides an accelerating attraction. This acceleration can be transformed
+ // from the reference frame of the planet so as to be expressed in the frame
+ // of reference of the aircraft. This gravity field accelerating attraction
+ // is felt by the pilot as a force on her tushie as she sits in her aircraft
+ // on the runway awaiting takeoff clearance.
+ //
+ // In JSBSim the acceleration of the body frame in inertial space is given
+ // by the F = ma relation. If the vForces vector is divided by the aircraft
+ // mass, the acceleration vector is calculated. The term wdot is equivalent
+ // to the JSBSim vPQRdot vector, and the w parameter is equivalent to vPQR.
+ // The radius R is calculated below in the vector vToEyePt.
- earthPosAngle += State->Getdt()*OMEGA_EARTH;
+ vPilotAccel.InitMatrix();
+ if ( Translation->GetVt() > 1 ) {
+ vPilotAccel = Aerodynamics->GetForces()
+ + Propulsion->GetForces()
+ + GroundReactions->GetForces();
+ vPilotAccel /= MassBalance->GetMass();
+ vToEyePt = MassBalance->StructuralToBody(Aircraft->GetXYZep());
+ vPilotAccel += Rotation->GetPQRdot() * vToEyePt;
+ vPilotAccel += Rotation->GetPQR() * (Rotation->GetPQR() * vToEyePt);
+ } else {
+ vPilotAccel = -1*( State->GetTl2b() * Inertial->GetGravity() );
+ }
+
+ vPilotAccelN = vPilotAccel/Inertial->gravity();
+ earthPosAngle += State->Getdt()*Inertial->omega();
+ return false;
} else {
+ return true;
}
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+double FGAuxiliary::GetHeadWind(void)
+{
+ double psiw,vw,psi;
+ psiw = Atmosphere->GetWindPsi();
+ psi = Rotation->Getpsi();
+ vw = Atmosphere->GetWindNED().Magnitude();
- return false;
+ return vw*cos(psiw - psi);
}
-void FGAuxiliary::GetState(void) {
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+double FGAuxiliary::GetCrossWind(void)
+{
+ double psiw,vw,psi;
+
+ psiw = Atmosphere->GetWindPsi();
+ psi = Rotation->Getpsi();
+ vw = Atmosphere->GetWindNED().Magnitude();
+
+ return vw*sin(psiw - psi);
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+void FGAuxiliary::bind(void)
+{
+ typedef double (FGAuxiliary::*PMF)(int) const;
+ 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/tat-r", this,
+ &FGAuxiliary::GetTotalTemperature);
+ PropertyManager->Tie("velocities/tat-c", this,
+ &FGAuxiliary::GetTAT_C);
+ PropertyManager->Tie("velocities/pt-lbs_sqft", this,
+ &FGAuxiliary::GetTotalPressure);
+
+ PropertyManager->Tie("accelerations/a-pilot-x-ft_sec2", this,1,
+ (PMF)&FGAuxiliary::GetPilotAccel);
+ PropertyManager->Tie("accelerations/a-pilot-y-ft_sec2", this,2,
+ (PMF)&FGAuxiliary::GetPilotAccel);
+ PropertyManager->Tie("accelerations/a-pilot-z-ft_sec2", this,3,
+ (PMF)&FGAuxiliary::GetPilotAccel);
+ PropertyManager->Tie("accelerations/n-pilot-x-norm", this,1,
+ (PMF)&FGAuxiliary::GetNpilot);
+ PropertyManager->Tie("accelerations/n-pilot-y-norm", this,2,
+ (PMF)&FGAuxiliary::GetNpilot);
+ PropertyManager->Tie("accelerations/n-pilot-z-norm", this,3,
+ (PMF)&FGAuxiliary::GetNpilot);
+ PropertyManager->Tie("position/epa-rad", this,
+ &FGAuxiliary::GetEarthPositionAngle);
+ /* PropertyManager->Tie("atmosphere/headwind-fps", this,
+ &FGAuxiliary::GetHeadWind,
+ true);
+ PropertyManager->Tie("atmosphere/crosswind-fps", this,
+ &FGAuxiliary::GetCrossWind,
+ true); */
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+void FGAuxiliary::unbind(void)
+{
+ PropertyManager->Untie("velocities/vc-fps");
+ PropertyManager->Untie("velocities/vc-kts");
+ PropertyManager->Untie("velocities/ve-fps");
+ PropertyManager->Untie("velocities/ve-kts");
+ PropertyManager->Untie("velocities/machU");
+ PropertyManager->Untie("velocities/tat-r");
+ PropertyManager->Untie("velocities/tat-c");
+ PropertyManager->Untie("accelerations/a-pilot-x-ft_sec2");
+ PropertyManager->Untie("accelerations/a-pilot-y-ft_sec2");
+ PropertyManager->Untie("accelerations/a-pilot-z-ft_sec2");
+ PropertyManager->Untie("accelerations/n-pilot-x-norm");
+ PropertyManager->Untie("accelerations/n-pilot-y-norm");
+ PropertyManager->Untie("accelerations/n-pilot-z-norm");
+ PropertyManager->Untie("position/epa-rad");
+ /* PropertyManager->Untie("atmosphere/headwind-fps");
+ PropertyManager->Untie("atmosphere/crosswind-fps"); */
+
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+void FGAuxiliary::GetState(void)
+{
qbar = Translation->Getqbar();
mach = Translation->GetMach();
+ machU= Translation->GetMachU();
p = Atmosphere->GetPressure();
rhosl = Atmosphere->GetDensitySL();
psl = Atmosphere->GetPressureSL();
+ sat = Atmosphere->GetTemperature();
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+// 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 (debug_lvl & 64) {
+ if (from == 0) { // Constructor
+ cout << IdSrc << endl;
+ cout << IdHdr << endl;
+ }
+ }
}
+} // namespace JSBSim