/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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
#include "FGAircraft.h"
#include "FGPosition.h"
#include "FGOutput.h"
-#include "FGMatrix.h"
+#include "FGInertial.h"
+#include "FGMatrix33.h"
+#include "FGColumnVector3.h"
+#include "FGColumnVector4.h"
static const char *IdSrc = "$Id$";
static const char *IdHdr = ID_AUXILIARY;
-extern short debug_lvl;
-
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
CLASS IMPLEMENTATION
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
-FGAuxiliary::FGAuxiliary(FGFDMExec* fdmex) : FGModel(fdmex) {
+FGAuxiliary::FGAuxiliary(FGFDMExec* fdmex) : FGModel(fdmex)
+{
Name = "FGAuxiliary";
vcas = veas = mach = qbar = pt = 0;
psl = rhosl = 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
+ if (mach < 1) { //calculate total pressure assuming isentropic flow
pt=p*pow((1 + 0.2*mach*mach),3.5);
- else {
+ } 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
vcas = sqrt(7*psl/rhosl*(A-1));
veas = sqrt(2*qbar/rhosl);
- vPilotAccel = Translation->GetUVWdot() + Aircraft->GetXYZep() * Rotation->GetPQRdot();
-
- earthPosAngle += State->Getdt()*OMEGA_EARTH;
-
+ // 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.
+
+ vToEyePt = Aircraft->GetXYZep() - MassBalance->GetXYZcg();
+
+ vPilotAccel = Aircraft->GetBodyAccel()
+ + Rotation->GetPQRdot() * vToEyePt
+ + Rotation->GetPQR() * (Rotation->GetPQR() * vToEyePt)
+ + Inertial->GetGravity();
+
+ earthPosAngle += State->Getdt()*Inertial->omega();
+ return false;
} else {
+ return true;
}
-
- return false;
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-float FGAuxiliary::GetHeadWind(void) {
-
- float psiw,vw,psi;
+double FGAuxiliary::GetHeadWind(void)
+{
+ double psiw,vw,psi;
psiw = Atmosphere->GetWindPsi();
psi = Rotation->Getpsi();
vw = Atmosphere->GetWindNED().Magnitude();
- return -vw*cos(psiw - psi);
+
+ return vw*cos(psiw - psi);
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-float FGAuxiliary::GetCrossWind(void) {
-
- float psiw,vw,psi;
+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::GetState(void) {
+FGColumnVector3 FGAuxiliary::GetNpilot(void)
+{
+ return vPilotAccel/Inertial->gravity();
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+double FGAuxiliary::GetNpilot(int idx)
+{
+ return (vPilotAccel/Inertial->gravity())(idx);
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+void FGAuxiliary::GetState(void)
+{
qbar = Translation->Getqbar();
mach = Translation->GetMach();
p = Atmosphere->GetPressure();
rhosl = Atmosphere->GetDensitySL();
psl = Atmosphere->GetPressureSL();
-
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-void FGAuxiliary::Debug(void)
+void FGAuxiliary::Debug(int from)
{
//TODO: Add your source code here
}
projects / flightgear.git / blobdiff