215 lines
6.7 KiB
C++
215 lines
6.7 KiB
C++
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
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
|
|
[2] D. M. Henderson, "Euler Angles, Quaternions, and Transformation Matrices",
|
|
JSC 12960, July 1977
|
|
[3] Richard E. McFarland, "A Standard Kinematic Model for Flight Simulation at
|
|
NASA-Ames", NASA CR-2497, January 1975
|
|
[4] Barnes W. McCormick, "Aerodynamics, Aeronautics, and Flight Mechanics",
|
|
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 <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 "FGAtmosphere.h"
|
|
#include "FGState.h"
|
|
#include "FGFDMExec.h"
|
|
#include "FGFCS.h"
|
|
#include "FGAircraft.h"
|
|
#include "FGMassBalance.h"
|
|
#include "FGTranslation.h"
|
|
#include "FGRotation.h"
|
|
#include "FGAuxiliary.h"
|
|
#include "FGOutput.h"
|
|
|
|
static const char *IdSrc = "$Id$";
|
|
static const char *IdHdr = ID_POSITION;
|
|
|
|
extern short debug_lvl;
|
|
|
|
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
CLASS IMPLEMENTATION
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
|
|
|
|
extern float globalTriNormal[3];
|
|
extern double globalSceneryAltitude;
|
|
extern double globalSeaLevelRadius;
|
|
|
|
FGPosition::FGPosition(FGFDMExec* fdmex) : FGModel(fdmex),
|
|
vVel(3),
|
|
vVelDot(3),
|
|
vRunwayNormal(3)
|
|
{
|
|
Name = "FGPosition";
|
|
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
|
|
|
|
if (debug_lvl & 2) cout << "Instantiated: " << Name << endl;
|
|
}
|
|
|
|
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
FGPosition::~FGPosition()
|
|
{
|
|
if (debug_lvl & 2) cout << "Destroyed: FGPosition" << endl;
|
|
}
|
|
|
|
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
/*
|
|
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) {
|
|
double cosLat;
|
|
double hdot_Vt;
|
|
|
|
if (!FGModel::Run()) {
|
|
GetState();
|
|
|
|
Vground = sqrt( vVel(eNorth)*vVel(eNorth) + vVel(eEast)*vVel(eEast) );
|
|
psigt = atan2(vVel(eEast), vVel(eNorth));
|
|
if(psigt < 0.0)
|
|
psigt += 2*M_PI;
|
|
|
|
invMass = 1.0 / MassBalance->GetMass();
|
|
Radius = h + SeaLevelRadius;
|
|
invRadius = 1.0 / Radius;
|
|
|
|
cosLat = cos(Latitude);
|
|
if (cosLat != 0) LongitudeDot = vVel(eEast) / (Radius * cosLat);
|
|
|
|
LatitudeDot = vVel(eNorth) * invRadius;
|
|
RadiusDot = -vVel(eDown);
|
|
|
|
Longitude += 0.5*dt*rate*(LongitudeDot + lastLongitudeDot);
|
|
Latitude += 0.5*dt*rate*(LatitudeDot + lastLatitudeDot);
|
|
Radius += 0.5*dt*rate*(RadiusDot + lastRadiusDot);
|
|
|
|
h = Radius - SeaLevelRadius; // Geocentric
|
|
|
|
DistanceAGL = Radius - RunwayRadius; // Geocentric
|
|
|
|
hoverb = DistanceAGL/b;
|
|
|
|
if (Vt > 0) {
|
|
hdot_Vt = RadiusDot/Vt;
|
|
if (fabs(hdot_Vt) <= 1) gamma = asin(hdot_Vt);
|
|
} else {
|
|
gamma = 0.0;
|
|
}
|
|
|
|
lastLatitudeDot = LatitudeDot;
|
|
lastLongitudeDot = LongitudeDot;
|
|
lastRadiusDot = RadiusDot;
|
|
|
|
return false;
|
|
|
|
} else {
|
|
return true;
|
|
}
|
|
}
|
|
|
|
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
void FGPosition::GetState(void) {
|
|
dt = State->Getdt();
|
|
|
|
Vt = Translation->GetVt();
|
|
vVel = State->GetTb2l() * Translation->GetUVW();
|
|
vVelDot = State->GetTb2l() * Translation->GetUVWdot();
|
|
|
|
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;
|
|
}
|
|
|
|
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
void FGPosition::Debug(void)
|
|
{
|
|
//TODO: Add your source code here
|
|
}
|
|
|