-/*******************************************************************************
-
+/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
Module: FGPosition.cpp
Author: Jon S. Berndt
Date started: 01/05/99
Purpose: Integrate the EOM to determine instantaneous position
Called by: FGFDMExec
-
+
------------- Copyright (C) 1999 Jon S. Berndt (jsb@hal-pc.org) -------------
-
+
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU 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 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 encapsulates the integration of rates and accelerations to get the
current position of the aircraft.
-
+
HISTORY
--------------------------------------------------------------------------------
01/05/99 JSB Created
-
-********************************************************************************
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
COMMENTS, REFERENCES, and NOTES
-********************************************************************************
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
[1] Cooke, Zyda, Pratt, and McGhee, "NPSNET: Flight Simulation Dynamic Modeling
Using Quaternions", Presence, Vol. 1, No. 4, pp. 404-420 Naval Postgraduate
School, January 1994
Wiley & Sons, 1979 ISBN 0-471-03032-5
[5] Bernard Etkin, "Dynamics of Flight, Stability and Control", Wiley & Sons,
1982 ISBN 0-471-08936-2
-
-********************************************************************************
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
INCLUDES
-*******************************************************************************/
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
#ifdef FGFS
-# include <Include/compiler.h>
-# ifdef FG_HAVE_STD_INCLUDES
+# include <simgear/compiler.h>
+# ifdef SG_HAVE_STD_INCLUDES
# include <cmath>
+# include <iomanip>
# else
# include <math.h>
+# include <iomanip.h>
# endif
#else
# include <cmath>
+# include <iomanip>
#endif
#include "FGPosition.h"
#include "FGAuxiliary.h"
#include "FGOutput.h"
-/*******************************************************************************
-************************************ CODE **************************************
-*******************************************************************************/
+static const char *IdSrc = "$Header$";
+static const char *IdHdr = ID_POSITION;
+
+/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+CLASS IMPLEMENTATION
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
+extern float globalTriNormal[3];
+extern double globalSceneryAltitude;
+extern double globalSeaLevelRadius;
-FGPosition::FGPosition(FGFDMExec* fdmex) : FGModel(fdmex)
+FGPosition::FGPosition(FGFDMExec* fdmex) : FGModel(fdmex),
+ vUVW(3),
+ vVel(3),
+ vVelDot(3),
+ vRunwayNormal(3)
{
Name = "FGPosition";
- AccelN = AccelE = AccelD = 0.0;
LongitudeDot = LatitudeDot = RadiusDot = 0.0;
+ lastLongitudeDot = lastLatitudeDot = lastRadiusDot = 0.0;
+ Longitude = Latitude = 0.0;
+ gamma = Vt = Vground = 0.0;
+ h = 3.0; // Est. height of aircraft cg off runway
+ SeaLevelRadius = EARTHRAD; // For initialization ONLY
+ Radius = SeaLevelRadius + h;
+ RunwayRadius = SeaLevelRadius;
+ DistanceAGL = Radius - RunwayRadius; // Geocentric
+ vRunwayNormal(3) = -1.0; // Initialized for standalone mode
}
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-FGPosition::~FGPosition(void)
-{
-}
+FGPosition::~FGPosition(void) {}
+/*************************************************************************** Run
+Purpose: Called on a schedule to perform Positioning algorithms
+Notes: [TP] Make sure that -Vt <= hdot <= Vt, which, of course, should always
+ be the case
+ [JB] Run in standalone mode, SeaLevelRadius will be EARTHRAD. In FGFS,
+ SeaLevelRadius is stuffed from FGJSBSim in JSBSim.cxx each pass.
+*/
-bool FGPosition:: Run(void)
-{
- float tanLat, cosLat;
+bool FGPosition:: Run(void) {
+ double cosLat;
+ double hdot_Vt;
if (!FGModel::Run()) {
GetState();
- T[1][1] = Q0*Q0 + Q1*Q1 - Q2*Q2 - Q3*Q3; // Page A-11
- T[1][2] = 2*(Q1*Q2 + Q0*Q3); // From
- T[1][3] = 2*(Q1*Q3 - Q0*Q2); // Reference [2]
- T[2][1] = 2*(Q1*Q2 - Q0*Q3);
- T[2][2] = Q0*Q0 - Q1*Q1 + Q2*Q2 - Q3*Q3;
- T[2][3] = 2*(Q2*Q3 + Q0*Q1);
- T[3][1] = 2*(Q1*Q3 + Q0*Q2);
- T[3][2] = 2*(Q2*Q3 - Q0*Q1);
- T[3][3] = Q0*Q0 - Q1*Q1 - Q2*Q2 + Q3*Q3;
-
- Fn = T[1][1]*Fx + T[2][1]*Fy + T[3][1]*Fz; // Eqn. 3.5
- Fe = T[1][2]*Fx + T[2][2]*Fy + T[3][2]*Fz; // From
- Fd = T[1][3]*Fx + T[2][3]*Fy + T[3][3]*Fz; // Reference [3]
-
- tanLat = tan(Latitude); // I made this up
+
+ Vground = sqrt( vVel(eNorth)*vVel(eNorth) + vVel(eEast)*vVel(eEast) );
+
+ invMass = 1.0 / Aircraft->GetMass();
+ Radius = h + SeaLevelRadius;
+ invRadius = 1.0 / Radius;
+
cosLat = cos(Latitude);
+ if (cosLat != 0) LongitudeDot = vVel(eEast) / (Radius * cosLat);
- lastAccelN = AccelN;
- lastAccelE = AccelE;
- lastAccelD = AccelD;
+ LatitudeDot = vVel(eNorth) * invRadius;
+ RadiusDot = -vVel(eDown);
- Vn = T[1][1]*U + T[2][1]*V + T[3][1]*W;
- Ve = T[1][2]*U + T[2][2]*V + T[3][2]*W;
- Vd = T[1][3]*U + T[2][3]*V + T[3][3]*W;
+ Longitude += 0.5*dt*rate*(LongitudeDot + lastLongitudeDot);
+ Latitude += 0.5*dt*rate*(LatitudeDot + lastLatitudeDot);
+ Radius += 0.5*dt*rate*(RadiusDot + lastRadiusDot);
-/* AccelN = invMass * Fn + invRadius * (Vn*Vd - Ve*Ve*tanLat); // Eqn. 3.6
- AccelE = invMass * Fe + invRadius * (Ve*Vd + Vn*Ve*tanLat); // From
- AccelD = invMass * Fd - invRadius * (Vn*Vn + Ve*Ve); // Reference [3]
+ h = Radius - SeaLevelRadius; // Geocentric
- Vn += 0.5*dt*rate*(3.0*AccelN - lastAccelN); // Eqn. 3.7
- Ve += 0.5*dt*rate*(3.0*AccelE - lastAccelE); // From
- Vd += 0.5*dt*rate*(3.0*AccelD - lastAccelD); // Reference [3]
+ DistanceAGL = Radius - RunwayRadius; // Geocentric
- Vee = Ve - OMEGAEARTH * (Radius) * cosLat; // From Eq. 3.8
-*/ // Reference [3]
- lastLatitudeDot = LatitudeDot;
- lastLongitudeDot = LongitudeDot;
- lastRadiusDot = RadiusDot;
+ hoverb = DistanceAGL/b;
- if (cosLat != 0) LongitudeDot = Ve / (Radius * cosLat);
- LatitudeDot = Vn * invRadius;
- RadiusDot = -Vd;
+ if (Vt > 0) {
+ hdot_Vt = RadiusDot/Vt;
+ if (fabs(hdot_Vt) <= 1) gamma = asin(hdot_Vt);
+ } else {
+ gamma = 0.0;
+ }
- Longitude += 0.5*dt*rate*(LongitudeDot + lastLongitudeDot);
- Latitude += 0.5*dt*rate*(LatitudeDot + lastLatitudeDot);
- Radius += 0.5*dt*rate*(RadiusDot + lastRadiusDot);
+ lastLatitudeDot = LatitudeDot;
+ lastLongitudeDot = LongitudeDot;
+ lastRadiusDot = RadiusDot;
- PutState();
return false;
+
} else {
return true;
}
}
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-void FGPosition::GetState(void)
-{
+void FGPosition::GetState(void) {
dt = State->Getdt();
- Q0 = Rotation->GetQ0();
- Q1 = Rotation->GetQ1();
- Q2 = Rotation->GetQ2();
- Q3 = Rotation->GetQ3();
-
- Fx = Aircraft->GetFx();
- Fy = Aircraft->GetFy();
- Fz = Aircraft->GetFz();
-
- U = Translation->GetU();
- V = Translation->GetV();
- W = Translation->GetW();
-
- Latitude = State->Getlatitude();
- Longitude = State->Getlongitude();
+ vUVW = Translation->GetUVW();
+ Vt = Translation->GetVt();
+ vVel = State->GetTb2l()*vUVW;
+ vVelDot = State->GetTb2l() * Translation->GetUVWdot();
- invMass = 1.0 / Aircraft->GetMass();
- invRadius = 1.0 / (State->Geth() + EARTHRAD);
- Radius = State->Geth() + EARTHRAD;
-}
-
-
-void FGPosition::PutState(void)
-{
- State->Setlatitude(Latitude);
- State->Setlongitude(Longitude);
- State->Seth(Radius - EARTHRAD);
+ b = Aircraft->GetWingSpan();
+
}
+void FGPosition::Seth(double tt) {
+ h=tt;
+ Radius = h + SeaLevelRadius;
+ DistanceAGL = Radius - RunwayRadius; // Geocentric
+}
+
+void FGPosition::SetDistanceAGL(double tt) {
+ DistanceAGL=tt;
+ Radius = RunwayRadius + DistanceAGL;
+ h = Radius - SeaLevelRadius;
+}
projects / flightgear.git / blobdiff