src/FDM/JSBSim/FGTranslation.cpp

   1 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   2
   3  Module:       FGTranslation.cpp
   4  Author:       Jon Berndt
   5  Date started: 12/02/98
   6  Purpose:      Integrates the translational EOM
   7  Called by:    FDMExec
   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 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 General Public License for more
  19  details.
  20
  21  You should have received a copy of the GNU 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 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 integrates the translational EOM.
  31
  32 HISTORY
  33 --------------------------------------------------------------------------------
  34 12/02/98   JSB   Created
  35  7/23/99   TP    Added data member and modified Run and PutState to calcuate
  36                  Mach number
  37
  38 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  39 COMMENTS, REFERENCES,  and NOTES
  40 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  41 [1] Cooke, Zyda, Pratt, and McGhee, "NPSNET: Flight Simulation Dynamic Modeling
  42     Using Quaternions", Presence, Vol. 1, No. 4, pp. 404-420  Naval Postgraduate
  43     School, January 1994
  44 [2] D. M. Henderson, "Euler Angles, Quaternions, and Transformation Matrices",
  45     JSC 12960, July 1977
  46 [3] Richard E. McFarland, "A Standard Kinematic Model for Flight Simulation at
  47     NASA-Ames", NASA CR-2497, January 1975
  48 [4] Barnes W. McCormick, "Aerodynamics, Aeronautics, and Flight Mechanics",
  49     Wiley & Sons, 1979 ISBN 0-471-03032-5
  50 [5] Bernard Etkin, "Dynamics of Flight, Stability and Control", Wiley & Sons,
  51     1982 ISBN 0-471-08936-2
  52
  53   The order of rotations used in this class corresponds to a 3-2-1 sequence,
  54   or Y-P-R, or Z-Y-X, if you prefer.
  55
  56 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  57 INCLUDES
  58 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  59
  60 #include "FGTranslation.h"
  61 #include "FGRotation.h"
  62 #include "FGAtmosphere.h"
  63 #include "FGState.h"
  64 #include "FGFDMExec.h"
  65 #include "FGFCS.h"
  66 #include "FGMassBalance.h"
  67 #include "FGAircraft.h"
  68 #include "FGPosition.h"
  69 #include "FGAuxiliary.h"
  70 #include "FGOutput.h"
  71 #include "FGPropertyManager.h"
  72
  73 namespace JSBSim {
  74
  75 static const char *IdSrc = "$Id$";
  76 static const char *IdHdr = ID_TRANSLATION;
  77
  78 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  79 CLASS IMPLEMENTATION
  80 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  81
  82
  83 FGTranslation::FGTranslation(FGFDMExec* fdmex) : FGModel(fdmex)
  84 {
  85   Name = "FGTranslation";
  86   qbar = 0;
  87   qbarUW = 0.0;
  88   qbarUV = 0.0;
  89   Vt = 0.0;
  90   Mach = 0.0;
  91   alpha = beta = 0.0;
  92   adot = bdot = 0.0;
  93
  94   vUVWdot.InitMatrix();
  95   vUVWdot_prev[0].InitMatrix();
  96   vUVWdot_prev[1].InitMatrix();
  97   vUVWdot_prev[2].InitMatrix();
  98   vUVWdot_prev[3].InitMatrix();
  99
 100   bind();
 101   Debug(0);
 102 }
 103
 104 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 105
 106 FGTranslation::~FGTranslation(void)
 107 {
 108   unbind();
 109   Debug(1);
 110 }
 111
 112 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 113
 114 bool FGTranslation::Run(void)
 115 {
 116   if (!FGModel::Run()) {
 117
 118     mVel(1,1) =  0.0;
 119     mVel(1,2) = -vUVW(eW);
 120     mVel(1,3) =  vUVW(eV);
 121     mVel(2,1) =  vUVW(eW);
 122     mVel(2,2) =  0.0;
 123     mVel(2,3) = -vUVW(eU);
 124     mVel(3,1) = -vUVW(eV);
 125     mVel(3,2) =  vUVW(eU);
 126     mVel(3,3) =  0.0;
 127
 128     vUVWdot = mVel*Rotation->GetPQR() + Aircraft->GetBodyAccel();
 129
 130     vUVW += State->Integrate(FGState::TRAPZ, State->Getdt()*rate, vUVWdot, vUVWdot_prev);
 131
 132     vAeroUVW = vUVW + State->GetTl2b()*Atmosphere->GetWindNED();
 133
 134     Vt = vAeroUVW.Magnitude();
 135     if ( Vt > 1) {
 136       if (vAeroUVW(eW) != 0.0)
 137         alpha = vAeroUVW(eU)*vAeroUVW(eU) > 0.0 ? atan2(vAeroUVW(eW), vAeroUVW(eU)) : 0.0;
 138       if (vAeroUVW(eV) != 0.0)
 139         beta = vAeroUVW(eU)*vAeroUVW(eU)+vAeroUVW(eW)*vAeroUVW(eW) > 0.0 ? atan2(vAeroUVW(eV),
 140                sqrt(vAeroUVW(eU)*vAeroUVW(eU) + vAeroUVW(eW)*vAeroUVW(eW))) : 0.0;
 141
 142       // stolen, quite shamelessly, from LaRCsim
 143       double mUW = (vAeroUVW(eU)*vAeroUVW(eU) + vAeroUVW(eW)*vAeroUVW(eW));
 144       double signU=1;
 145       if (vAeroUVW(eU) != 0.0)
 146         signU = vAeroUVW(eU)/fabs(vAeroUVW(eU));
 147
 148       if ( (mUW == 0.0) || (Vt == 0.0) ) {
 149         adot = 0.0;
 150         bdot = 0.0;
 151       } else {
 152         adot = (vAeroUVW(eU)*vAeroUVW(eW) - vAeroUVW(eW)*vUVWdot(eU))/mUW;
 153         bdot = (signU*mUW*vUVWdot(eV) - vAeroUVW(eV)*(vAeroUVW(eU)*vUVWdot(eU)
 154                 + vAeroUVW(eW)*vUVWdot(eW)))/(Vt*Vt*sqrt(mUW));
 155       }
 156     } else {
 157       alpha = beta = adot = bdot = 0;
 158     }
 159
 160     qbar = 0.5*Atmosphere->GetDensity()*Vt*Vt;
 161     qbarUW = 0.5*Atmosphere->GetDensity()*(vAeroUVW(eU)*vAeroUVW(eU) + vAeroUVW(eW)*vAeroUVW(eW));
 162     qbarUV = 0.5*Atmosphere->GetDensity()*(vAeroUVW(eU)*vAeroUVW(eU) + vAeroUVW(eV)*vAeroUVW(eV));
 163     Mach = Vt / State->Geta();
 164     vMachUVW(eU) = vAeroUVW(eU) / State->Geta();
 165     vMachUVW(eV) = vAeroUVW(eV) / State->Geta();
 166     vMachUVW(eW) = vAeroUVW(eW) / State->Geta();
 167
 168     if (debug_lvl > 1) Debug(1);
 169
 170     return false;
 171   } else {
 172     return true;
 173   }
 174 }
 175
 176 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 177
 178 void FGTranslation::bind(void)
 179 {
 180   typedef double (FGTranslation::*PMF)(int) const;
 181   PropertyManager->Tie("velocities/u-fps", this,1,
 182                        (PMF)&FGTranslation::GetUVW /*,
 183                        &FGTranslation::SetUVW,
 184                        true */);
 185   PropertyManager->Tie("velocities/v-fps", this,2,
 186                        (PMF)&FGTranslation::GetUVW /*,
 187                        &FGTranslation::SetUVW,
 188                        true*/);
 189   PropertyManager->Tie("velocities/w-fps", this,3,
 190                        (PMF)&FGTranslation::GetUVW /*,
 191                        &FGTranslation::SetUVW,
 192                        true*/);
 193   PropertyManager->Tie("accelerations/udot-fps", this,1,
 194                        (PMF)&FGTranslation::GetUVWdot);
 195   PropertyManager->Tie("accelerations/vdot-fps", this,2,
 196                        (PMF)&FGTranslation::GetUVWdot);
 197   PropertyManager->Tie("accelerations/wdot-fps", this,3,
 198                        (PMF)&FGTranslation::GetUVWdot);
 199   PropertyManager->Tie("velocities/u-aero-fps", this,1,
 200                        (PMF)&FGTranslation::GetAeroUVW);
 201   PropertyManager->Tie("velocities/v-aero-fps", this,2,
 202                        (PMF)&FGTranslation::GetAeroUVW);
 203   PropertyManager->Tie("velocities/w-aero-fps", this,3,
 204                        (PMF)&FGTranslation::GetAeroUVW);
 205   PropertyManager->Tie("aero/alpha-rad", this,
 206                        &FGTranslation::Getalpha,
 207                        &FGTranslation::Setalpha,
 208                        true);
 209   PropertyManager->Tie("aero/beta-rad", this,
 210                        &FGTranslation::Getbeta,
 211                        &FGTranslation::Setbeta,
 212                        true);
 213   PropertyManager->Tie("aero/mag-beta-rad", this,
 214                        &FGTranslation::GetMagBeta);
 215   PropertyManager->Tie("aero/qbar-psf", this,
 216                        &FGTranslation::Getqbar,
 217                        &FGTranslation::Setqbar,
 218                        true);
 219   PropertyManager->Tie("aero/qbarUW-psf", this,
 220                        &FGTranslation::GetqbarUW,
 221                        &FGTranslation::SetqbarUW,
 222                        true);
 223   PropertyManager->Tie("aero/qbarUV-psf", this,
 224                        &FGTranslation::GetqbarUV,
 225                        &FGTranslation::SetqbarUV,
 226                        true);
 227   PropertyManager->Tie("velocities/vt-fps", this,
 228                        &FGTranslation::GetVt,
 229                        &FGTranslation::SetVt,
 230                        true);
 231   PropertyManager->Tie("velocities/mach-norm", this,
 232                        &FGTranslation::GetMach,
 233                        &FGTranslation::SetMach,
 234                        true);
 235   PropertyManager->Tie("aero/alphadot-rad_sec", this,
 236                        &FGTranslation::Getadot,
 237                        &FGTranslation::Setadot,
 238                        true);
 239   PropertyManager->Tie("aero/betadot-rad_sec", this,
 240                        &FGTranslation::Getbdot,
 241                        &FGTranslation::Setbdot,
 242                        true);
 243 }
 244
 245 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 246
 247 void FGTranslation::unbind(void)
 248 {
 249   PropertyManager->Untie("velocities/u-fps");
 250   PropertyManager->Untie("velocities/v-fps");
 251   PropertyManager->Untie("velocities/w-fps");
 252   PropertyManager->Untie("accelerations/udot-fps");
 253   PropertyManager->Untie("accelerations/vdot-fps");
 254   PropertyManager->Untie("accelerations/wdot-fps");
 255   PropertyManager->Untie("velocities/u-aero-fps");
 256   PropertyManager->Untie("velocities/v-aero-fps");
 257   PropertyManager->Untie("velocities/w-aero-fps");
 258   PropertyManager->Untie("aero/alpha-rad");
 259   PropertyManager->Untie("aero/beta-rad");
 260   PropertyManager->Untie("aero/qbar-psf");
 261   PropertyManager->Untie("aero/qbarUW-psf");
 262   PropertyManager->Untie("aero/qbarUV-psf");
 263   PropertyManager->Untie("velocities/vt-fps");
 264   PropertyManager->Untie("velocities/mach-norm");
 265   PropertyManager->Untie("aero/alphadot-rad_sec");
 266   PropertyManager->Untie("aero/betadot-rad_sec");
 267   PropertyManager->Untie("aero/mag-beta-rad");
 268 }
 269
 270 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 271 //    The bitmasked value choices are as follows:
 272 //    unset: In this case (the default) JSBSim would only print
 273 //       out the normally expected messages, essentially echoing
 274 //       the config files as they are read. If the environment
 275 //       variable is not set, debug_lvl is set to 1 internally
 276 //    0: This requests JSBSim not to output any messages
 277 //       whatsoever.
 278 //    1: This value explicity requests the normal JSBSim
 279 //       startup messages
 280 //    2: This value asks for a message to be printed out when
 281 //       a class is instantiated
 282 //    4: When this value is set, a message is displayed when a
 283 //       FGModel object executes its Run() method
 284 //    8: When this value is set, various runtime state variables
 285 //       are printed out periodically
 286 //    16: When set various parameters are sanity checked and
 287 //       a message is printed out when they go out of bounds
 288
 289 void FGTranslation::Debug(int from)
 290 {
 291   if (debug_lvl <= 0) return;
 292
 293   if (debug_lvl & 1) { // Standard console startup message output
 294     if (from == 0) { // Constructor
 295
 296     }
 297   }
 298   if (debug_lvl & 2 ) { // Instantiation/Destruction notification
 299     if (from == 0) cout << "Instantiated: FGTranslation" << endl;
 300     if (from == 1) cout << "Destroyed:    FGTranslation" << endl;
 301   }
 302   if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
 303   }
 304   if (debug_lvl & 8 ) { // Runtime state variables
 305   }
 306   if (debug_lvl & 16) { // Sanity checking
 307     if (fabs(vUVW(eU)) > 1e6)
 308       cout << "FGTranslation::U velocity out of bounds: " << vUVW(eU) << endl;
 309     if (fabs(vUVW(eV)) > 1e6)
 310       cout << "FGTranslation::V velocity out of bounds: " << vUVW(eV) << endl;
 311     if (fabs(vUVW(eW)) > 1e6)
 312       cout << "FGTranslation::W velocity out of bounds: " << vUVW(eW) << endl;
 313     if (fabs(vUVWdot(eU)) > 1e4)
 314       cout << "FGTranslation::U acceleration out of bounds: " << vUVWdot(eU) << endl;
 315     if (fabs(vUVWdot(eV)) > 1e4)
 316       cout << "FGTranslation::V acceleration out of bounds: " << vUVWdot(eV) << endl;
 317     if (fabs(vUVWdot(eW)) > 1e4)
 318       cout << "FGTranslation::W acceleration out of bounds: " << vUVWdot(eW) << endl;
 319     if (Mach > 100 || Mach < 0.00)
 320       cout << "FGTranslation::Mach is out of bounds: " << Mach << endl;
 321     if (qbar > 1e6 || qbar < 0.00)
 322       cout << "FGTranslation::qbar is out of bounds: " << qbar << endl;
 323   }
 324   if (debug_lvl & 64) {
 325     if (from == 0) { // Constructor
 326       cout << IdSrc << endl;
 327       cout << IdHdr << endl;
 328     }
 329   }
 330 }
 331 }