src/FDM/JSBSim/FGAerodynamics.cpp

   1 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   2
   3  Module:       FGAerodynamics.cpp
   4  Author:       Jon S. Berndt
   5  Date started: 09/13/00
   6  Purpose:      Encapsulates the aerodynamic forces (gear and collision)
   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 HISTORY
  31 --------------------------------------------------------------------------------
  32 09/13/00   JSB   Created
  33 04/22/01   JSB   Moved code into here from FGAircraft
  34
  35 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  36 INCLUDES
  37 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  38
  39 #include "FGAerodynamics.h"
  40 #include "FGFactorGroup.h"
  41 #include "FGCoefficient.h"
  42
  43 static const char *IdSrc = "$Id$";
  44 static const char *IdHdr = ID_AERODYNAMICS;
  45
  46 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  47 CLASS IMPLEMENTATION
  48 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  49
  50
  51 FGAerodynamics::FGAerodynamics(FGFDMExec* FDMExec) : FGModel(FDMExec),
  52     vMoments(3),
  53     vForces(3),
  54     vFs(3),
  55     vLastFs(3),
  56     vDXYZcg(3)
  57 {
  58   Name = "FGAerodynamics";
  59
  60   AxisIdx["DRAG"]  = 0;
  61   AxisIdx["SIDE"]  = 1;
  62   AxisIdx["LIFT"]  = 2;
  63   AxisIdx["ROLL"]  = 3;
  64   AxisIdx["PITCH"] = 4;
  65   AxisIdx["YAW"]   = 5;
  66
  67   Coeff = new CoeffArray[6];
  68
  69   if (debug_lvl & 2) cout << "Instantiated: FGAerodynamics" << endl;
  70 }
  71
  72 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  73
  74 FGAerodynamics::~FGAerodynamics()
  75 {
  76   unsigned int i,j;
  77   for (i=0; i<6; i++) {
  78     for (j=0; j<Coeff[i].size(); j++) {
  79       delete Coeff[i][j];
  80     }
  81   }
  82   delete[] Coeff;
  83
  84   if (debug_lvl & 2) cout << "Destroyed:    FGAerodynamics" << endl;
  85 }
  86
  87 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  88
  89 bool FGAerodynamics::Run(void)
  90 {
  91   float alpha, beta;
  92   unsigned int axis_ctr,ctr;
  93
  94   if (!FGModel::Run()) {
  95
  96     alpha = Translation->Getalpha();
  97     beta = Translation->Getbeta();
  98
  99     vLastFs = vFs;
 100     vFs.InitMatrix();
 101
 102     for (axis_ctr = 0; axis_ctr < 3; axis_ctr++) {
 103       for (ctr=0; ctr < Coeff[axis_ctr].size(); ctr++) {
 104         vFs(axis_ctr+1) += Coeff[axis_ctr][ctr]->TotalValue();
 105       }
 106     }
 107
 108     vForces = State->GetTs2b(alpha, beta)*vFs;
 109
 110     vDXYZcg(eX) = -(Aircraft->GetXYZrp(eX)
 111                       - MassBalance->GetXYZcg(eX))*INCHTOFT;
 112     vDXYZcg(eY) =  (Aircraft->GetXYZrp(eY)
 113                       - MassBalance->GetXYZcg(eY))*INCHTOFT;
 114     vDXYZcg(eZ) = -(Aircraft->GetXYZrp(eZ)
 115                       - MassBalance->GetXYZcg(eZ))*INCHTOFT;
 116
 117     vMoments = vDXYZcg*vForces; // M = r X F
 118
 119     for (axis_ctr = 0; axis_ctr < 3; axis_ctr++) {
 120       for (ctr = 0; ctr < Coeff[axis_ctr+3].size(); ctr++) {
 121         vMoments(axis_ctr+1) += Coeff[axis_ctr+3][ctr]->TotalValue();
 122       }
 123     }
 124     return false;
 125   } else {
 126     return true;
 127   }
 128 }
 129
 130 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 131
 132 bool FGAerodynamics::Load(FGConfigFile* AC_cfg)
 133 {
 134   string token, axis;
 135
 136   AC_cfg->GetNextConfigLine();
 137
 138   while ((token = AC_cfg->GetValue()) != "/AERODYNAMICS") {
 139     if (token == "AXIS") {
 140       CoeffArray ca;
 141       axis = AC_cfg->GetValue("NAME");
 142       AC_cfg->GetNextConfigLine();
 143       while ((token = AC_cfg->GetValue()) != "/AXIS") {
 144         if( token == "COEFFICIENT" ) {
 145           ca.push_back( new FGCoefficient(FDMExec) );
 146           ca.back()->Load(AC_cfg);
 147         } else if ( token == "GROUP" ) {
 148           ca.push_back( new FGFactorGroup(FDMExec) );
 149           ca.back()->Load(AC_cfg);
 150         }
 151       }
 152       Coeff[AxisIdx[axis]] = ca;
 153       AC_cfg->GetNextConfigLine();
 154     }
 155   }
 156
 157   return true;
 158 }
 159
 160 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 161
 162 string FGAerodynamics::GetCoefficientStrings(void)
 163 {
 164   string CoeffStrings = "";
 165   bool firstime = true;
 166   unsigned int axis, sd;
 167
 168   for (axis = 0; axis < 6; axis++) {
 169     for (sd = 0; sd < Coeff[axis].size(); sd++) {
 170       if (firstime) {
 171         firstime = false;
 172       } else {
 173         CoeffStrings += ", ";
 174       }
 175       CoeffStrings += Coeff[axis][sd]->GetCoefficientStrings();
 176     }
 177   }
 178   return CoeffStrings;
 179 }
 180
 181 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 182
 183 string FGAerodynamics::GetCoefficientValues(void)
 184 {
 185   string SDValues = "";
 186   char buffer[10];
 187   bool firstime = true;
 188
 189   for (unsigned int axis = 0; axis < 6; axis++) {
 190     for (unsigned int sd = 0; sd < Coeff[axis].size(); sd++) {
 191       if (firstime) {
 192         firstime = false;
 193       } else {
 194         SDValues += ", ";
 195       }
 196       SDValues += Coeff[axis][sd]->GetCoefficientValues();
 197     }
 198   }
 199
 200   return SDValues;
 201 }
 202
 203 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 204
 205 float FGAerodynamics::GetNlf(void)
 206 {
 207   if (fabs(Position->GetGamma()) < 1.57) {
 208     return (vFs(eZ)/(MassBalance->GetWeight()*cos(Position->GetGamma())));
 209   } else {
 210     return 0.0;
 211   }
 212 }
 213
 214 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 215
 216 float FGAerodynamics::GetLoD(void)
 217 {
 218   float LoD;
 219
 220   if (vFs(1) != 0.00) return vFs(3)/vFs(1);
 221   else                return 0.00;
 222 }
 223
 224 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 225
 226 void FGAerodynamics::Debug(void)
 227 {
 228     //TODO: Add your source code here
 229 }
 230