fgtrimaxis.cpp

6 DOF Missle Simulation

/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

 Header:       FGTrimAxis.cpp
 Author:       Tony Peden
 Date started: 7/3/00

 --------- Copyright (C) 1999  Anthony K. Peden ([e-mail]) ---------

 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.


 HISTORY
--------------------------------------------------------------------------------
7/3/00   TP   Created

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
INCLUDES
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/

#ifdef _MSC_VER
#  pragma warning (disable : 4786)
#endif

#include <string>
#include <cstdlib>
#include <FGFDMExec.h>
#include <models/FGAtmosphere.h>
#include "FGInitialCondition.h"
#include "FGTrimAxis.h"
#include <models/FGAircraft.h>
#include <models/FGPropulsion.h>
#include <models/FGAerodynamics.h>

namespace JSBSim {

static const char *IdSrc = "$Id$";
static const char *IdHdr = ID_TRIMAXIS;

/*****************************************************************************/

FGTrimAxis::FGTrimAxis(FGFDMExec* fdex, FGInitialCondition* ic, State st,
                       Control ctrl) {

  fdmex=fdex;
  fgic=ic;
  state=st;
  control=ctrl;
  max_iterations=10;
  control_value=0;
  its_to_stable_value=0;
  total_iterations=0;
  total_stability_iterations=0;
  state_convert=1.0;
  control_convert=1.0;
  state_value=0;
  state_target=0;
  switch(state) {
    case tUdot: tolerance = DEFAULT_TOLERANCE; break;
    case tVdot: tolerance = DEFAULT_TOLERANCE; break;
    case tWdot: tolerance = DEFAULT_TOLERANCE; break;
    case tQdot: tolerance = DEFAULT_TOLERANCE / 10; break;
    case tPdot: tolerance = DEFAULT_TOLERANCE / 10; break;
    case tRdot: tolerance = DEFAULT_TOLERANCE / 10; break;
    case tHmgt: tolerance = 0.01; break;
    case  tNlf: state_target=1.0; tolerance = 1E-5; break;
    case tAll: break;
  }

  solver_eps=tolerance;
  switch(control) {
  case tThrottle:
    control_min=0;
    control_max=1;
    control_value=0.5;
    break;
  case tBeta:
    control_min=-30*degtorad;
    control_max=30*degtorad;
    control_convert=radtodeg;
    break;
  case tAlpha:
    control_min=fdmex->GetAerodynamics()->GetAlphaCLMin();
    control_max=fdmex->GetAerodynamics()->GetAlphaCLMax();
    if(control_max <= control_min) {
      control_max=20*degtorad;
      control_min=-5*degtorad;
    }
    control_value= (control_min+control_max)/2;
    control_convert=radtodeg;
    solver_eps=tolerance/100;
    break;
  case tPitchTrim:
  case tElevator:
  case tRollTrim:
  case tAileron:
  case tYawTrim:
  case tRudder:
    control_min=-1;
    control_max=1;
    state_convert=radtodeg;
    solver_eps=tolerance/100;
    break;
  case tAltAGL:
    control_min=0;
    control_max=30;
    control_value=fdmex->GetPropagate()->GetDistanceAGL();
    solver_eps=tolerance/100;
    break;
  case tTheta:
    control_min=fdmex->GetPropagate()->GetEuler(eTht) - 5*degtorad;
    control_max=fdmex->GetPropagate()->GetEuler(eTht) + 5*degtorad;
    state_convert=radtodeg;
    break;
  case tPhi:
    control_min=fdmex->GetPropagate()->GetEuler(ePhi) - 30*degtorad;
    control_max=fdmex->GetPropagate()->GetEuler(ePhi) + 30*degtorad;
    state_convert=radtodeg;
    control_convert=radtodeg;
    break;
  case tGamma:
    solver_eps=tolerance/100;
    control_min=-80*degtorad;
    control_max=80*degtorad;
    control_convert=radtodeg;
    break;
  case tHeading:
    control_min=fdmex->GetPropagate()->GetEuler(ePsi) - 30*degtorad;
    control_max=fdmex->GetPropagate()->GetEuler(ePsi) + 30*degtorad;
    state_convert=radtodeg;
    break;
  }


  Debug(0);
}

/*****************************************************************************/

FGTrimAxis::~FGTrimAxis(void)
{
  Debug(1);
}

/*****************************************************************************/

void FGTrimAxis::getState(void) {
  switch(state) {
  case tUdot: state_value=fdmex->GetPropagate()->GetUVWdot(1)-state_target; break;
  case tVdot: state_value=fdmex->GetPropagate()->GetUVWdot(2)-state_target; break;
  case tWdot: state_value=fdmex->GetPropagate()->GetUVWdot(3)-state_target; break;
  case tQdot: state_value=fdmex->GetPropagate()->GetPQRdot(2)-state_target;break;
  case tPdot: state_value=fdmex->GetPropagate()->GetPQRdot(1)-state_target; break;
  case tRdot: state_value=fdmex->GetPropagate()->GetPQRdot(3)-state_target; break;
  case tHmgt: state_value=computeHmgt()-state_target; break;
  case tNlf:  state_value=fdmex->GetAircraft()->GetNlf()-state_target; break;
  case tAll: break;
  }
}

/*****************************************************************************/

//States are not settable

void FGTrimAxis::getControl(void) {
  switch(control) {
  case tThrottle:  control_value=fdmex->GetFCS()->GetThrottleCmd(0); break;
  case tBeta:      control_value=fdmex->GetAuxiliary()->Getbeta(); break;
  case tAlpha:     control_value=fdmex->GetAuxiliary()->Getalpha();  break;
  case tPitchTrim: control_value=fdmex->GetFCS() -> GetPitchTrimCmd(); break;
  case tElevator:  control_value=fdmex->GetFCS() -> GetDeCmd(); break;
  case tRollTrim:
  case tAileron:   control_value=fdmex->GetFCS() -> GetDaCmd(); break;
  case tYawTrim:
  case tRudder:    control_value=fdmex->GetFCS() -> GetDrCmd(); break;
  case tAltAGL:    control_value=fdmex->GetPropagate()->GetDistanceAGL();break;
  case tTheta:     control_value=fdmex->GetPropagate()->GetEuler(eTht); break;
  case tPhi:       control_value=fdmex->GetPropagate()->GetEuler(ePhi); break;
  case tGamma:     control_value=fdmex->GetAuxiliary()->GetGamma();break;
  case tHeading:   control_value=fdmex->GetPropagate()->GetEuler(ePsi); break;
  }
}

/*****************************************************************************/

double FGTrimAxis::computeHmgt(void) {
  double diff;

  diff   = fdmex->GetPropagate()->GetEuler(ePsi) -
             fdmex->GetAuxiliary()->GetGroundTrack();

  if( diff < -M_PI ) {
     return (diff + 2*M_PI);
  } else if( diff > M_PI ) {
     return (diff - 2*M_PI);
  } else {
     return diff;
  }

}

/*****************************************************************************/


void FGTrimAxis::setControl(void) {
  switch(control) {
  case tThrottle:  setThrottlesPct(); break;
  case tBeta:      fgic->SetBetaRadIC(control_value); break;
  case tAlpha:     fgic->SetAlphaRadIC(control_value);  break;
  case tPitchTrim: fdmex->GetFCS()->SetPitchTrimCmd(control_value); break;
  case tElevator:  fdmex->GetFCS()->SetDeCmd(control_value); break;
  case tRollTrim:
  case tAileron:   fdmex->GetFCS()->SetDaCmd(control_value); break;
  case tYawTrim:
  case tRudder:    fdmex->GetFCS()->SetDrCmd(control_value); break;
  case tAltAGL:    fgic->SetAltitudeAGLFtIC(control_value); break;
  case tTheta:     fgic->SetThetaRadIC(control_value); break;
  case tPhi:       fgic->SetPhiRadIC(control_value); break;
  case tGamma:     fgic->SetFlightPathAngleRadIC(control_value); break;
  case tHeading:   fgic->SetPsiRadIC(control_value); break;
  }
}





/*****************************************************************************/

// the aircraft center of rotation is no longer the cg once the gear
// contact the ground so the altitude needs to be changed when pitch
// and roll angle are adjusted.  Instead of attempting to calculate the
// new center of rotation, pick a gear unit as a reference and use its
// location vector to calculate the new height change. i.e. new altitude =
// earth z component of that vector (which is in body axes )
void FGTrimAxis::SetThetaOnGround(double ff) {