src/FDM/JSBSim/FGMassBalance.cpp

   1 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   2
   3  Module:       FGMassBalance.cpp
   4  Author:       Jon S. Berndt
   5  Date started: 09/12/2000
   6  Purpose:      This module models weight and balance
   7
   8  ------------- Copyright (C) 2000  Jon S. Berndt (jsb@hal-pc.org) --------------
   9
  10  This program is free software; you can redistribute it and/or modify it under
  11  the terms of the GNU General Public License as published by the Free Software
  12  Foundation; either version 2 of the License, or (at your option) any later
  13  version.
  14
  15  This program is distributed in the hope that it will be useful, but WITHOUT
  16  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  17  FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  18  details.
  19
  20  You should have received a copy of the GNU General Public License along with
  21  this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  22  Place - Suite 330, Boston, MA  02111-1307, USA.
  23
  24  Further information about the GNU General Public License can also be found on
  25  the world wide web at http://www.gnu.org.
  26
  27 FUNCTIONAL DESCRIPTION
  28 --------------------------------------------------------------------------------
  29
  30 This class models the change in weight and balance of the aircraft due to fuel
  31 burnoff, etc.
  32
  33 HISTORY
  34 --------------------------------------------------------------------------------
  35 09/12/2000  JSB  Created
  36
  37 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  38 INCLUDES
  39 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  40
  41 #include "FGMassBalance.h"
  42 #include "FGPropertyManager.h"
  43
  44 namespace JSBSim {
  45
  46 static const char *IdSrc = "$Id$";
  47 static const char *IdHdr = ID_MASSBALANCE;
  48
  49 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  50 CLASS IMPLEMENTATION
  51 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  52
  53
  54 FGMassBalance::FGMassBalance(FGFDMExec* fdmex) : FGModel(fdmex)
  55 {
  56   Name = "FGMassBalance";
  57   Weight = EmptyWeight = Mass = 0.0;
  58   Ixx = Iyy = Izz = Ixy = Ixz = 0.0;
  59   baseIxx = baseIyy = baseIzz = baseIxy = baseIxz = 0.0;
  60   vbaseXYZcg(eX) = 0.0;
  61   vbaseXYZcg(eY) = 0.0;
  62   vbaseXYZcg(eZ) = 0.0;
  63   bind();
  64
  65   Debug(0);
  66 }
  67
  68 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  69
  70 FGMassBalance::~FGMassBalance()
  71 {
  72   unbind();
  73   Debug(1);
  74 }
  75
  76 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  77
  78 bool FGMassBalance::Run(void)
  79 {
  80   if (!FGModel::Run()) {
  81
  82     Weight = EmptyWeight + Propulsion->GetTanksWeight() + GetPointMassWeight();
  83
  84     Mass = Weight / Inertial->gravity();
  85
  86 // Calculate new CG here.
  87
  88     vXYZcg = (Propulsion->GetTanksMoment() + EmptyWeight*vbaseXYZcg
  89                                        + GetPointMassMoment() ) / Weight;
  90
  91 // Calculate new moments of inertia here
  92
  93     Ixx = baseIxx + Propulsion->GetTanksIxx(vXYZcg) + GetPMIxx();
  94     Iyy = baseIyy + Propulsion->GetTanksIyy(vXYZcg) + GetPMIyy();
  95     Izz = baseIzz + Propulsion->GetTanksIzz(vXYZcg) + GetPMIzz();
  96     Ixy = baseIxy + Propulsion->GetTanksIxy(vXYZcg) + GetPMIxy();
  97     Ixz = baseIxz + Propulsion->GetTanksIxz(vXYZcg) + GetPMIxz();
  98
  99     Debug(2);
 100
 101     return false;
 102   } else {
 103     return true;
 104   }
 105 }
 106
 107 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 108
 109 void FGMassBalance::AddPointMass(double weight, double X, double Y, double Z)
 110 {
 111   PointMassLoc.push_back(*(new FGColumnVector3(X, Y, Z)));
 112   PointMassWeight.push_back(weight);
 113 }
 114
 115 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 116
 117 double FGMassBalance::GetPointMassWeight(void)
 118 {
 119   double PM_total_weight = 0.0;
 120
 121   for (unsigned int i=0; i<PointMassWeight.size(); i++) {
 122     PM_total_weight += PointMassWeight[i];
 123   }
 124   return PM_total_weight;
 125 }
 126
 127 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 128
 129 FGColumnVector3& FGMassBalance::GetPointMassMoment(void)
 130 {
 131   PointMassCG.InitMatrix();
 132
 133   for (unsigned int i=0; i<PointMassLoc.size(); i++) {
 134     PointMassCG += PointMassWeight[i]*PointMassLoc[i];
 135   }
 136   return PointMassCG;
 137 }
 138
 139 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 140
 141 double FGMassBalance::GetPMIxx(void)
 142 {
 143   double I = 0.0;
 144   for (unsigned int i=0; i<PointMassLoc.size(); i++) {
 145     I += (PointMassLoc[i](eX)-vXYZcg(eX))*(PointMassLoc[i](eX)-vXYZcg(eX))*PointMassWeight[i];
 146   }
 147   I /= (144.0*Inertial->gravity());
 148   return I;
 149 }
 150
 151 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 152
 153 double FGMassBalance::GetPMIyy(void)
 154 {
 155   double I = 0.0;
 156   for (unsigned int i=0; i<PointMassLoc.size(); i++) {
 157     I += (PointMassLoc[i](eY)-vXYZcg(eY))*(PointMassLoc[i](eY)-vXYZcg(eY))*PointMassWeight[i];
 158   }
 159   I /= (144.0*Inertial->gravity());
 160   return I;
 161 }
 162
 163 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 164
 165 double FGMassBalance::GetPMIzz(void)
 166 {
 167   double I = 0.0;
 168   for (unsigned int i=0; i<PointMassLoc.size(); i++) {
 169     I += (PointMassLoc[i](eZ)-vXYZcg(eZ))*(PointMassLoc[i](eZ)-vXYZcg(eZ))*PointMassWeight[i];
 170   }
 171   I /= (144.0*Inertial->gravity());
 172   return I;
 173 }
 174
 175 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 176
 177 double FGMassBalance::GetPMIxy(void)
 178 {
 179   double I = 0.0;
 180   for (unsigned int i=0; i<PointMassLoc.size(); i++) {
 181     I += (PointMassLoc[i](eX)-vXYZcg(eX))*(PointMassLoc[i](eY)-vXYZcg(eY))*PointMassWeight[i];
 182   }
 183   I /= (144.0*Inertial->gravity());
 184   return I;
 185 }
 186
 187 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 188
 189 double FGMassBalance::GetPMIxz(void)
 190 {
 191   double I = 0.0;
 192   for (unsigned int i=0; i<PointMassLoc.size(); i++) {
 193     I += (PointMassLoc[i](eX)-vXYZcg(eX))*(PointMassLoc[i](eZ)-vXYZcg(eZ))*PointMassWeight[i];
 194   }
 195   I /= (144.0*Inertial->gravity());
 196   return I;
 197 }
 198
 199 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 200
 201 FGColumnVector3 FGMassBalance::StructuralToBody(const FGColumnVector3& r) const
 202 {
 203   // Under the assumption that in the structural frame the:
 204   //
 205   // - X-axis is directed afterwards,
 206   // - Y-axis is directed towards the right,
 207   // - Z-axis is directed upwards,
 208   //
 209   // (as documented in http://jsbsim.sourceforge.net/JSBSimCoordinates.pdf)
 210   // we have to subtract first the center of gravity of the plane which
 211   // is also defined in the structural frame:
 212   //
 213   //   FGColumnVector3 cgOff = r - vXYZcg;
 214   //
 215   // Next, we do a change of units:
 216   //
 217   //   cgOff *= inchtoft;
 218   //
 219   // And then a 180 degree rotation is done about the Y axis so that the:
 220   //
 221   // - X-axis is directed forward,
 222   // - Y-axis is directed towards the right,
 223   // - Z-axis is directed downward.
 224   //
 225   // This is needed because the structural and body frames are 180 degrees apart.
 226
 227   return FGColumnVector3(inchtoft*(vXYZcg(1)-r(1)),
 228                          inchtoft*(r(2)-vXYZcg(2)),
 229                          inchtoft*(vXYZcg(3)-r(3)));
 230 }
 231
 232 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 233
 234 void FGMassBalance::bind(void)
 235 {
 236   typedef double (FGMassBalance::*PMF)(int) const;
 237   PropertyManager->Tie("inertia/mass-slugs", this,
 238                        &FGMassBalance::GetMass);
 239   PropertyManager->Tie("inertia/weight-lbs", this,
 240                        &FGMassBalance::GetWeight);
 241   PropertyManager->Tie("inertia/ixx-lbsft2", this,
 242                        &FGMassBalance::GetIxx);
 243   PropertyManager->Tie("inertia/iyy-lbsft2", this,
 244                        &FGMassBalance::GetIyy);
 245   PropertyManager->Tie("inertia/izz-lbsft2", this,
 246                        &FGMassBalance::GetIzz);
 247   PropertyManager->Tie("inertia/ixy-lbsft2", this,
 248                        &FGMassBalance::GetIxy);
 249   PropertyManager->Tie("inertia/ixz-lbsft2", this,
 250                        &FGMassBalance::GetIxz);
 251   PropertyManager->Tie("inertia/cg-x-ft", this,1,
 252                        (PMF)&FGMassBalance::GetXYZcg);
 253   PropertyManager->Tie("inertia/cg-y-ft", this,2,
 254                        (PMF)&FGMassBalance::GetXYZcg);
 255   PropertyManager->Tie("inertia/cg-z-ft", this,3,
 256                        (PMF)&FGMassBalance::GetXYZcg);
 257 }
 258
 259 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 260
 261 void FGMassBalance::unbind(void)
 262 {
 263   PropertyManager->Untie("inertia/mass-slugs");
 264   PropertyManager->Untie("inertia/weight-lbs");
 265   PropertyManager->Untie("inertia/ixx-lbsft2");
 266   PropertyManager->Untie("inertia/iyy-lbsft2");
 267   PropertyManager->Untie("inertia/izz-lbsft2");
 268   PropertyManager->Untie("inertia/ixy-lbsft2");
 269   PropertyManager->Untie("inertia/ixz-lbsft2");
 270   PropertyManager->Untie("inertia/cg-x-ft");
 271   PropertyManager->Untie("inertia/cg-y-ft");
 272   PropertyManager->Untie("inertia/cg-z-ft");
 273 }
 274
 275 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 276 //    The bitmasked value choices are as follows:
 277 //    unset: In this case (the default) JSBSim would only print
 278 //       out the normally expected messages, essentially echoing
 279 //       the config files as they are read. If the environment
 280 //       variable is not set, debug_lvl is set to 1 internally
 281 //    0: This requests JSBSim not to output any messages
 282 //       whatsoever.
 283 //    1: This value explicity requests the normal JSBSim
 284 //       startup messages
 285 //    2: This value asks for a message to be printed out when
 286 //       a class is instantiated
 287 //    4: When this value is set, a message is displayed when a
 288 //       FGModel object executes its Run() method
 289 //    8: When this value is set, various runtime state variables
 290 //       are printed out periodically
 291 //    16: When set various parameters are sanity checked and
 292 //       a message is printed out when they go out of bounds
 293
 294 void FGMassBalance::Debug(int from)
 295 {
 296   if (debug_lvl <= 0) return;
 297
 298   if (debug_lvl & 1) { // Standard console startup message output
 299     if (from == 0) { // Constructor
 300
 301     }
 302   }
 303   if (debug_lvl & 2 ) { // Instantiation/Destruction notification
 304     if (from == 0) cout << "Instantiated: FGPiston" << endl;
 305     if (from == 1) cout << "Destroyed:    FGPiston" << endl;
 306   }
 307   if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
 308   }
 309   if (debug_lvl & 8 ) { // Runtime state variables
 310   }
 311   if (debug_lvl & 16) { // Sanity checking
 312     if (from == 2) {
 313       if (EmptyWeight <= 0.0 || EmptyWeight > 1e9)
 314         cout << "MassBalance::EmptyWeight out of bounds: " << EmptyWeight << endl;
 315       if (Weight <= 0.0 || Weight > 1e9)
 316         cout << "MassBalance::Weight out of bounds: " << Weight << endl;
 317       if (Mass <= 0.0 || Mass > 1e9)
 318         cout << "MassBalance::Mass out of bounds: " << Mass << endl;
 319     }
 320   }
 321   if (debug_lvl & 64) {
 322     if (from == 0) { // Constructor
 323       cout << IdSrc << endl;
 324       cout << IdHdr << endl;
 325     }
 326   }
 327 }
 328 }