src/FDM/JSBSim/models/FGPropagate.cpp

   1 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   2
   3  Module:       FGPropagate.cpp
   4  Author:       Jon S. Berndt
   5  Date started: 01/05/99
   6  Purpose:      Integrate the EOM to determine instantaneous position
   7  Called by:    FGFDMExec
   8
   9  ------------- Copyright (C) 1999  Jon S. Berndt (jsb@hal-pc.org) -------------
  10
  11  This program is free software; you can redistribute it and/or modify it under
  12  the terms of the GNU Lesser General Public License as published by the Free Software
  13  Foundation; either version 2 of the License, or (at your option) any later
  14  version.
  15
  16  This program is distributed in the hope that it will be useful, but WITHOUT
  17  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  18  FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
  19  details.
  20
  21  You should have received a copy of the GNU Lesser General Public License along with
  22  this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  23  Place - Suite 330, Boston, MA  02111-1307, USA.
  24
  25  Further information about the GNU Lesser General Public License can also be found on
  26  the world wide web at http://www.gnu.org.
  27
  28 FUNCTIONAL DESCRIPTION
  29 --------------------------------------------------------------------------------
  30 This class encapsulates the integration of rates and accelerations to get the
  31 current position of the aircraft.
  32
  33 HISTORY
  34 --------------------------------------------------------------------------------
  35 01/05/99   JSB   Created
  36
  37 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  38 COMMENTS, REFERENCES,  and NOTES
  39 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  40 [1] Cooke, Zyda, Pratt, and McGhee, "NPSNET: Flight Simulation Dynamic Modeling
  41     Using Quaternions", Presence, Vol. 1, No. 4, pp. 404-420  Naval Postgraduate
  42     School, January 1994
  43 [2] D. M. Henderson, "Euler Angles, Quaternions, and Transformation Matrices",
  44     JSC 12960, July 1977
  45 [3] Richard E. McFarland, "A Standard Kinematic Model for Flight Simulation at
  46     NASA-Ames", NASA CR-2497, January 1975
  47 [4] Barnes W. McCormick, "Aerodynamics, Aeronautics, and Flight Mechanics",
  48     Wiley & Sons, 1979 ISBN 0-471-03032-5
  49 [5] Bernard Etkin, "Dynamics of Flight, Stability and Control", Wiley & Sons,
  50     1982 ISBN 0-471-08936-2
  51
  52 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  53 INCLUDES
  54 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  55
  56 #ifdef FGFS
  57 #  include <simgear/compiler.h>
  58 #  ifdef SG_HAVE_STD_INCLUDES
  59 #    include <cmath>
  60 #    include <iomanip>
  61 #  else
  62 #    include <math.h>
  63 #    include <iomanip.h>
  64 #  endif
  65 #else
  66 #  if defined(sgi) && !defined(__GNUC__)
  67 #    include <math.h>
  68 #    if (_COMPILER_VERSION < 740)
  69 #      include <iomanip.h>
  70 #    else
  71 #      include <iomanip>
  72 #    endif
  73 #  else
  74 #    include <cmath>
  75 #    include <iomanip>
  76 #  endif
  77 #endif
  78
  79 #include "FGPropagate.h"
  80 #include <FGState.h>
  81 #include <FGFDMExec.h>
  82 #include "FGAircraft.h"
  83 #include "FGMassBalance.h"
  84 #include "FGInertial.h"
  85 #include <input_output/FGPropertyManager.h>
  86
  87 namespace JSBSim {
  88
  89 static const char *IdSrc = "$Id$";
  90 static const char *IdHdr = ID_PROPAGATE;
  91
  92 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  93 CLASS IMPLEMENTATION
  94 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  95
  96 FGPropagate::FGPropagate(FGFDMExec* fdmex) : FGModel(fdmex)
  97 {
  98   Name = "FGPropagate";
  99 //  vQtrndot.zero();
 100
 101   last2_vPQRdot.InitMatrix();
 102   last_vPQRdot.InitMatrix();
 103   vPQRdot.InitMatrix();
 104
 105   last2_vUVWdot.InitMatrix();
 106   last_vUVWdot.InitMatrix();
 107   vUVWdot.InitMatrix();
 108
 109   last2_vLocationDot.InitMatrix();
 110   last_vLocationDot.InitMatrix();
 111   vLocationDot.InitMatrix();
 112
 113   bind();
 114   Debug(0);
 115 }
 116
 117 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 118
 119 FGPropagate::~FGPropagate(void)
 120 {
 121   unbind();
 122   Debug(1);
 123 }
 124
 125 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 126
 127 bool FGPropagate::InitModel(void)
 128 {
 129   FGModel::InitModel();
 130
 131   SeaLevelRadius = Inertial->RefRadius();          // For initialization ONLY
 132   RunwayRadius   = SeaLevelRadius;
 133
 134   VState.vLocation.SetRadius( SeaLevelRadius + 4.0 );
 135
 136   return true;
 137 }
 138
 139 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 140
 141 void FGPropagate::SetInitialState(const FGInitialCondition *FGIC)
 142 {
 143   SeaLevelRadius = FGIC->GetSeaLevelRadiusFtIC();
 144   RunwayRadius = SeaLevelRadius;
 145
 146   // Set the position lat/lon/radius
 147   VState.vLocation = FGLocation( FGIC->GetLongitudeRadIC(),
 148                           FGIC->GetLatitudeRadIC(),
 149                           FGIC->GetAltitudeFtIC() + FGIC->GetSeaLevelRadiusFtIC() );
 150
 151   // Set the Orientation from the euler angles
 152   VState.vQtrn = FGQuaternion( FGIC->GetPhiRadIC(),
 153                         FGIC->GetThetaRadIC(),
 154                         FGIC->GetPsiRadIC() );
 155
 156   // Set the velocities in the instantaneus body frame
 157   VState.vUVW = FGColumnVector3( FGIC->GetUBodyFpsIC(),
 158                           FGIC->GetVBodyFpsIC(),
 159                           FGIC->GetWBodyFpsIC() );
 160
 161   // Set the angular velocities in the instantaneus body frame.
 162   VState.vPQR = FGColumnVector3( FGIC->GetPRadpsIC(),
 163                           FGIC->GetQRadpsIC(),
 164                           FGIC->GetRRadpsIC() );
 165
 166   // Compute some derived values.
 167   vVel = VState.vQtrn.GetTInv()*VState.vUVW;
 168
 169   // Finally, make sure that the quaternion stays normalized.
 170   VState.vQtrn.Normalize();
 171
 172   // Recompute the RunwayRadius level.
 173   RecomputeRunwayRadius();
 174 }
 175
 176 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 177 /*
 178 Purpose: Called on a schedule to perform EOM integration
 179 Notes:   [JB] Run in standalone mode, SeaLevelRadius will be reference radius.
 180          In FGFS, SeaLevelRadius is stuffed from FGJSBSim in JSBSim.cxx each pass.
 181
 182 At the top of this Run() function, see several "shortcuts" (or, aliases) being
 183 set up for use later, rather than using the longer class->function() notation.
 184
 185 Here, propagation of state is done using a simple explicit Euler scheme (see the
 186 bottom of the function). This propagation is done using the current state values
 187 and current derivatives. Based on these values we compute an approximation to the
 188 state values for (now + dt).
 189
 190 */
 191
 192 bool FGPropagate::Run(void)
 193 {
 194   if (FGModel::Run()) return true;  // Fast return if we have nothing to do ...
 195   if (FDMExec->Holding()) return false;
 196
 197   RecomputeRunwayRadius();
 198
 199   double dt = State->Getdt()*rate;  // The 'stepsize'
 200   const FGColumnVector3 omega( 0.0, 0.0, Inertial->omega() ); // earth rotation
 201   const FGColumnVector3& vForces = Aircraft->GetForces();     // current forces
 202   const FGColumnVector3& vMoments = Aircraft->GetMoments();   // current moments
 203
 204   double mass = MassBalance->GetMass();             // mass
 205   const FGMatrix33& J = MassBalance->GetJ();        // inertia matrix
 206   const FGMatrix33& Jinv = MassBalance->GetJinv();  // inertia matrix inverse
 207   double r = GetRadius();                           // radius
 208   if (r == 0.0) {cerr << "radius = 0 !" << endl; r = 1e-16;} // radius check
 209   double rInv = 1.0/r;
 210   FGColumnVector3 gAccel( 0.0, 0.0, Inertial->GetGAccel(r) );
 211
 212   // The rotation matrices:
 213   const FGMatrix33& Tl2b = GetTl2b();  // local to body frame
 214   const FGMatrix33& Tb2l = GetTb2l();  // body to local frame
 215   const FGMatrix33& Tec2l = VState.vLocation.GetTec2l();  // earth centered to local frame
 216   const FGMatrix33& Tl2ec = VState.vLocation.GetTl2ec();  // local to earth centered frame
 217
 218   // Inertial angular velocity measured in the body frame.
 219   const FGColumnVector3 pqri = VState.vPQR + Tl2b*(Tec2l*omega);
 220
 221   // Compute vehicle velocity wrt EC frame, expressed in Local horizontal frame.
 222   vVel = Tb2l * VState.vUVW;
 223
 224   // First compute the time derivatives of the vehicle state values:
 225
 226   // Compute body frame rotational accelerations based on the current body moments
 227   vPQRdot = Jinv*(vMoments - pqri*(J*pqri));
 228
 229   // Compute body frame accelerations based on the current body forces
 230   vUVWdot = VState.vUVW*VState.vPQR + vForces/mass;
 231
 232   // Coriolis acceleration.
 233   FGColumnVector3 ecVel = Tl2ec*vVel;
 234   FGColumnVector3 ace = 2.0*omega*ecVel;
 235   vUVWdot -= Tl2b*(Tec2l*ace);
 236
 237   if (!GroundReactions->GetWOW()) {
 238     // Centrifugal acceleration.
 239     FGColumnVector3 aeec = omega*(omega*VState.vLocation);
 240     vUVWdot -= Tl2b*(Tec2l*aeec);
 241   }
 242
 243   // Gravitation accel
 244   vUVWdot += Tl2b*gAccel;
 245
 246   // Compute vehicle velocity wrt EC frame, expressed in EC frame
 247   vLocationDot = Tl2ec * vVel;
 248
 249   FGColumnVector3 omegaLocal( rInv*vVel(eEast),
 250                               -rInv*vVel(eNorth),
 251                               -rInv*vVel(eEast)*VState.vLocation.GetTanLatitude() );
 252
 253   // Compute quaternion orientation derivative on current body rates
 254   vQtrndot = VState.vQtrn.GetQDot( VState.vPQR - Tl2b*omegaLocal );
 255
 256   // Integrate to propagate the state
 257
 258   // Propagate rotational velocity
 259
 260   // VState.vPQR += dt*(1.5*vPQRdot - 0.5*last_vPQRdot); // Adams-Bashforth
 261   VState.vPQR += (1/12.0)*dt*(23.0*vPQRdot - 16.0*last_vPQRdot + 5.0*last2_vPQRdot); // Adams-Bashforth 3
 262   // VState.vPQR += dt*vPQRdot;                          // Rectangular Euler
 263   // VState.vPQR += 0.5*dt*(vPQRdot + last_vPQRdot);     // Trapezoidal
 264
 265   // Propagate translational velocity
 266
 267   // VState.vUVW += dt*(1.5*vUVWdot - 0.5*last_vUVWdot); // Adams Bashforth
 268   VState.vUVW += (1/12.0)*dt*(23.0*vUVWdot - 16.0*last_vUVWdot + 5.0*last2_vUVWdot); // Adams-Bashforth 3
 269   // VState.vUVW += dt*vUVWdot;                         // Rectangular Euler
 270   // VState.vUVW += 0.5*dt*(vUVWdot + last_vUVWdot);    // Trapezoidal
 271
 272   // Propagate angular position
 273
 274   // VState.vQtrn += dt*(1.5*vQtrndot - 0.5*last_vQtrndot); // Adams Bashforth
 275   VState.vQtrn += (1/12.0)*dt*(23.0*vQtrndot - 16.0*last_vQtrndot + 5.0*last2_vQtrndot); // Adams-Bashforth 3
 276   // VState.vQtrn += dt*vQtrndot;                           // Rectangular Euler
 277   // VState.vQtrn += 0.5*dt*(vQtrndot + last_vQtrndot);     // Trapezoidal
 278
 279   // Propagate translational position
 280
 281   // VState.vLocation += dt*(1.5*vLocationDot - 0.5*last_vLocationDot); // Adams Bashforth
 282   VState.vLocation += (1/12.0)*dt*(23.0*vLocationDot - 16.0*last_vLocationDot + 5.0*last2_vLocationDot); // Adams-Bashforth 3
 283   // VState.vLocation += dt*vLocationDot;                               // Rectangular Euler
 284   // VState.vLocation += 0.5*dt*(vLocationDot + last_vLocationDot);     // Trapezoidal
 285
 286   // Set past values
 287
 288   last2_vPQRdot = last_vPQRdot;
 289   last_vPQRdot = vPQRdot;
 290
 291   last2_vUVWdot = last_vUVWdot;
 292   last_vUVWdot = vUVWdot;
 293
 294   last2_vQtrndot = last_vQtrndot;
 295   last_vQtrndot = vQtrndot;
 296
 297   last2_vLocationDot = last_vLocationDot;
 298   last_vLocationDot = vLocationDot;
 299
 300   return false;
 301 }
 302
 303 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 304
 305 void FGPropagate::RecomputeRunwayRadius(void)
 306 {
 307   // Get the runway radius.
 308   FGLocation contactloc;
 309   FGColumnVector3 dv;
 310   FGGroundCallback* gcb = FDMExec->GetGroundCallback();
 311   double t = State->Getsim_time();
 312   gcb->GetAGLevel(t, VState.vLocation, contactloc, dv, dv);
 313   RunwayRadius = contactloc.GetRadius();
 314 }
 315
 316 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 317
 318 void FGPropagate::Seth(double tt)
 319 {
 320   VState.vLocation.SetRadius( tt + SeaLevelRadius );
 321 }
 322
 323 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 324
 325 double FGPropagate::GetRunwayRadius(void) const
 326 {
 327   return RunwayRadius;
 328 }
 329
 330 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 331
 332 double FGPropagate::GetDistanceAGL(void) const
 333 {
 334   return VState.vLocation.GetRadius() - RunwayRadius;
 335 }
 336
 337 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 338
 339 void FGPropagate::SetDistanceAGL(double tt)
 340 {
 341   VState.vLocation.SetRadius( tt + RunwayRadius );
 342 }
 343
 344 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 345
 346 void FGPropagate::bind(void)
 347 {
 348   typedef double (FGPropagate::*PMF)(int) const;
 349   PropertyManager->Tie("velocities/h-dot-fps", this, &FGPropagate::Gethdot);
 350
 351   PropertyManager->Tie("velocities/v-north-fps", this, eNorth, (PMF)&FGPropagate::GetVel);
 352   PropertyManager->Tie("velocities/v-east-fps", this, eEast, (PMF)&FGPropagate::GetVel);
 353   PropertyManager->Tie("velocities/v-down-fps", this, eDown, (PMF)&FGPropagate::GetVel);
 354
 355   PropertyManager->Tie("velocities/u-fps", this, eU, (PMF)&FGPropagate::GetUVW);
 356   PropertyManager->Tie("velocities/v-fps", this, eV, (PMF)&FGPropagate::GetUVW);
 357   PropertyManager->Tie("velocities/w-fps", this, eW, (PMF)&FGPropagate::GetUVW);
 358
 359   PropertyManager->Tie("velocities/p-rad_sec", this, eP, (PMF)&FGPropagate::GetPQR);
 360   PropertyManager->Tie("velocities/q-rad_sec", this, eQ, (PMF)&FGPropagate::GetPQR);
 361   PropertyManager->Tie("velocities/r-rad_sec", this, eR, (PMF)&FGPropagate::GetPQR);
 362
 363   PropertyManager->Tie("accelerations/pdot-rad_sec", this, eP, (PMF)&FGPropagate::GetPQRdot);
 364   PropertyManager->Tie("accelerations/qdot-rad_sec", this, eQ, (PMF)&FGPropagate::GetPQRdot);
 365   PropertyManager->Tie("accelerations/rdot-rad_sec", this, eR, (PMF)&FGPropagate::GetPQRdot);
 366
 367   PropertyManager->Tie("accelerations/udot-fps", this, eU, (PMF)&FGPropagate::GetUVWdot);
 368   PropertyManager->Tie("accelerations/vdot-fps", this, eV, (PMF)&FGPropagate::GetUVWdot);
 369   PropertyManager->Tie("accelerations/wdot-fps", this, eW, (PMF)&FGPropagate::GetUVWdot);
 370
 371   PropertyManager->Tie("position/h-sl-ft", this, &FGPropagate::Geth, &FGPropagate::Seth, true);
 372   PropertyManager->Tie("position/lat-gc-rad", this, &FGPropagate::GetLatitude, &FGPropagate::SetLatitude);
 373   PropertyManager->Tie("position/long-gc-rad", this, &FGPropagate::GetLongitude, &FGPropagate::SetLongitude);
 374   PropertyManager->Tie("position/h-agl-ft", this,  &FGPropagate::GetDistanceAGL, &FGPropagate::SetDistanceAGL);
 375   PropertyManager->Tie("position/radius-to-vehicle-ft", this, &FGPropagate::GetRadius);
 376
 377   PropertyManager->Tie("metrics/runway-radius", this, &FGPropagate::GetRunwayRadius);
 378
 379   PropertyManager->Tie("attitude/phi-rad", this, (int)ePhi, (PMF)&FGPropagate::GetEuler);
 380   PropertyManager->Tie("attitude/theta-rad", this, (int)eTht, (PMF)&FGPropagate::GetEuler);
 381   PropertyManager->Tie("attitude/psi-rad", this, (int)ePsi, (PMF)&FGPropagate::GetEuler);
 382
 383   PropertyManager->Tie("attitude/roll-rad", this, (int)ePhi, (PMF)&FGPropagate::GetEuler);
 384   PropertyManager->Tie("attitude/pitch-rad", this, (int)eTht, (PMF)&FGPropagate::GetEuler);
 385   PropertyManager->Tie("attitude/heading-true-rad", this, (int)ePsi, (PMF)&FGPropagate::GetEuler);
 386 }
 387
 388 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 389
 390 void FGPropagate::unbind(void)
 391 {
 392   PropertyManager->Untie("velocities/v-north-fps");
 393   PropertyManager->Untie("velocities/v-east-fps");
 394   PropertyManager->Untie("velocities/v-down-fps");
 395   PropertyManager->Untie("velocities/h-dot-fps");
 396   PropertyManager->Untie("velocities/u-fps");
 397   PropertyManager->Untie("velocities/v-fps");
 398   PropertyManager->Untie("velocities/w-fps");
 399   PropertyManager->Untie("velocities/p-rad_sec");
 400   PropertyManager->Untie("velocities/q-rad_sec");
 401   PropertyManager->Untie("velocities/r-rad_sec");
 402   PropertyManager->Untie("accelerations/udot-fps");
 403   PropertyManager->Untie("accelerations/vdot-fps");
 404   PropertyManager->Untie("accelerations/wdot-fps");
 405   PropertyManager->Untie("accelerations/pdot-rad_sec");
 406   PropertyManager->Untie("accelerations/qdot-rad_sec");
 407   PropertyManager->Untie("accelerations/rdot-rad_sec");
 408   PropertyManager->Untie("position/h-sl-ft");
 409   PropertyManager->Untie("position/lat-gc-rad");
 410   PropertyManager->Untie("position/long-gc-rad");
 411   PropertyManager->Untie("position/h-agl-ft");
 412   PropertyManager->Untie("position/radius-to-vehicle-ft");
 413   PropertyManager->Untie("metrics/runway-radius");
 414   PropertyManager->Untie("attitude/phi-rad");
 415   PropertyManager->Untie("attitude/theta-rad");
 416   PropertyManager->Untie("attitude/psi-rad");
 417   PropertyManager->Untie("attitude/roll-rad");
 418   PropertyManager->Untie("attitude/pitch-rad");
 419   PropertyManager->Untie("attitude/heading-true-rad");
 420 }
 421
 422 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 423 //    The bitmasked value choices are as follows:
 424 //    unset: In this case (the default) JSBSim would only print
 425 //       out the normally expected messages, essentially echoing
 426 //       the config files as they are read. If the environment
 427 //       variable is not set, debug_lvl is set to 1 internally
 428 //    0: This requests JSBSim not to output any messages
 429 //       whatsoever.
 430 //    1: This value explicity requests the normal JSBSim
 431 //       startup messages
 432 //    2: This value asks for a message to be printed out when
 433 //       a class is instantiated
 434 //    4: When this value is set, a message is displayed when a
 435 //       FGModel object executes its Run() method
 436 //    8: When this value is set, various runtime state variables
 437 //       are printed out periodically
 438 //    16: When set various parameters are sanity checked and
 439 //       a message is printed out when they go out of bounds
 440
 441 void FGPropagate::Debug(int from)
 442 {
 443   if (debug_lvl <= 0) return;
 444
 445   if (debug_lvl & 1) { // Standard console startup message output
 446     if (from == 0) { // Constructor
 447
 448     }
 449   }
 450   if (debug_lvl & 2 ) { // Instantiation/Destruction notification
 451     if (from == 0) cout << "Instantiated: FGPropagate" << endl;
 452     if (from == 1) cout << "Destroyed:    FGPropagate" << endl;
 453   }
 454   if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
 455   }
 456   if (debug_lvl & 8 ) { // Runtime state variables
 457   }
 458   if (debug_lvl & 16) { // Sanity checking
 459   }
 460   if (debug_lvl & 64) {
 461     if (from == 0) { // Constructor
 462       cout << IdSrc << endl;
 463       cout << IdHdr << endl;
 464     }
 465   }
 466 }
 467 }