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
  43 static const char *IdSrc = "$Id$";
  44 static const char *IdHdr = ID_MASSBALANCE;
  45
  46 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  47 CLASS IMPLEMENTATION
  48 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  49
  50
  51 FGMassBalance::FGMassBalance(FGFDMExec* fdmex) : FGModel(fdmex)
  52 {
  53   Name = "FGMassBalance";
  54
  55   if (debug_lvl & 2) cout << "Instantiated: FGMassBalance" << endl;
  56 }
  57
  58 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  59
  60 FGMassBalance::~FGMassBalance()
  61 {
  62   if (debug_lvl & 2) cout << "Destroyed:    FGMassBalance" << endl;
  63 }
  64
  65 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  66
  67 bool FGMassBalance::Run(void)
  68 {
  69   if (!FGModel::Run()) {
  70
  71     Weight = EmptyWeight + Propulsion->GetTanksWeight() + GetPointMassWeight();
  72
  73     Mass = Weight / Inertial->gravity();
  74
  75 // Calculate new CG here.
  76
  77     vXYZcg = (Propulsion->GetTanksCG() + EmptyWeight*vbaseXYZcg
  78                                        + GetPointMassCG()       ) / Weight;
  79
  80 // Calculate new moments of inertia here
  81
  82     Ixx = baseIxx + Propulsion->GetTanksIxx(vXYZcg) + GetPMIxx();
  83     Iyy = baseIyy + Propulsion->GetTanksIyy(vXYZcg) + GetPMIyy();
  84     Izz = baseIzz + Propulsion->GetTanksIzz(vXYZcg) + GetPMIzz();
  85     Ixy = baseIxy + Propulsion->GetTanksIxy(vXYZcg) + GetPMIxy();
  86     Ixz = baseIxz + Propulsion->GetTanksIxz(vXYZcg) + GetPMIxz();
  87
  88     if (debug_lvl > 1) Debug();
  89
  90     return false;
  91   } else {
  92     return true;
  93   }
  94 }
  95
  96 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  97
  98 void FGMassBalance::AddPointMass(double weight, double X, double Y, double Z)
  99 {
 100   PointMassLoc.push_back(*(new FGColumnVector3(X, Y, Z)));
 101   PointMassWeight.push_back(weight);
 102 }
 103
 104 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 105
 106 double FGMassBalance::GetPointMassWeight(void)
 107 {
 108   double PM_total_weight = 0.0;
 109
 110   for (unsigned int i=0; i<PointMassWeight.size(); i++) {
 111     PM_total_weight += PointMassWeight[i];
 112   }
 113   return PM_total_weight;
 114 }
 115
 116 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 117
 118 FGColumnVector3& FGMassBalance::GetPointMassCG(void)
 119 {
 120   PointMassCG.InitMatrix();
 121
 122   for (unsigned int i=0; i<PointMassLoc.size(); i++) {
 123     PointMassCG += PointMassWeight[i]*PointMassLoc[i];
 124   }
 125   return PointMassCG;
 126 }
 127
 128 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 129
 130 double FGMassBalance::GetPMIxx(void)
 131 {
 132   double I = 0.0;
 133   for (unsigned int i=0; i<PointMassLoc.size(); i++) {
 134     I += PointMassLoc[i](eX)*PointMassLoc[i](eX)*PointMassWeight[i];
 135   }
 136   I /= (144.0*Inertial->gravity());
 137   return I;
 138 }
 139
 140 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 141
 142 double FGMassBalance::GetPMIyy(void)
 143 {
 144   double I = 0.0;
 145   for (unsigned int i=0; i<PointMassLoc.size(); i++) {
 146     I += PointMassLoc[i](eY)*PointMassLoc[i](eY)*PointMassWeight[i];
 147   }
 148   I /= (144.0*Inertial->gravity());
 149   return I;
 150 }
 151
 152 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 153
 154 double FGMassBalance::GetPMIzz(void)
 155 {
 156   double I = 0.0;
 157   for (unsigned int i=0; i<PointMassLoc.size(); i++) {
 158     I += PointMassLoc[i](eZ)*PointMassLoc[i](eZ)*PointMassWeight[i];
 159   }
 160   I /= (144.0*Inertial->gravity());
 161   return I;
 162 }
 163
 164 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 165
 166 double FGMassBalance::GetPMIxy(void)
 167 {
 168   double I = 0.0;
 169   for (unsigned int i=0; i<PointMassLoc.size(); i++) {
 170     I += PointMassLoc[i](eX)*PointMassLoc[i](eY)*PointMassWeight[i];
 171   }
 172   I /= (144.0*Inertial->gravity());
 173   return I;
 174 }
 175
 176 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 177
 178 double FGMassBalance::GetPMIxz(void)
 179 {
 180   double I = 0.0;
 181   for (unsigned int i=0; i<PointMassLoc.size(); i++) {
 182     I += PointMassLoc[i](eX)*PointMassLoc[i](eZ)*PointMassWeight[i];
 183   }
 184   I /= (144.0*Inertial->gravity());
 185   return I;
 186 }
 187
 188 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 189
 190 void FGMassBalance::Debug(void)
 191 {
 192   if (debug_lvl & 16) { // Sanity check variables
 193     if (EmptyWeight <= 0.0 || EmptyWeight > 1e9)
 194       cout << "MassBalance::EmptyWeight out of bounds: " << EmptyWeight << endl;
 195     if (Weight <= 0.0 || Weight > 1e9)
 196       cout << "MassBalance::Weight out of bounds: " << Weight << endl;
 197     if (Mass <= 0.0 || Mass > 1e9)
 198       cout << "MassBalance::Mass out of bounds: " << Mass << endl;
 199   }
 200 }
 201