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   unsigned int axis_ctr,ctr;
  92
  93   if (!FGModel::Run()) {
  94
  95     vLastFs = vFs;
  96     vFs.InitMatrix();
  97
  98     for (axis_ctr = 0; axis_ctr < 3; axis_ctr++) {
  99       for (ctr=0; ctr < Coeff[axis_ctr].size(); ctr++) {
 100         vFs(axis_ctr+1) += Coeff[axis_ctr][ctr]->TotalValue();
 101       }
 102     }
 103     //correct signs of drag and lift to wind axes convention
 104     //positive forward, right, down
 105     vFs(1)*=-1; vFs(3)*=-1;
 106     //cout << "Aircraft::vFs: " << vFs << endl;
 107     vForces = State->GetTs2b()*vFs;
 108
 109     vDXYZcg(eX) = -(Aircraft->GetXYZrp(eX)
 110                       - MassBalance->GetXYZcg(eX))*inchtoft;
 111     vDXYZcg(eY) =  (Aircraft->GetXYZrp(eY)
 112                       - MassBalance->GetXYZcg(eY))*inchtoft;
 113     vDXYZcg(eZ) = -(Aircraft->GetXYZrp(eZ)
 114                       - MassBalance->GetXYZcg(eZ))*inchtoft;
 115
 116     vMoments = vDXYZcg*vForces; // M = r X F
 117
 118     for (axis_ctr = 0; axis_ctr < 3; axis_ctr++) {
 119       for (ctr = 0; ctr < Coeff[axis_ctr+3].size(); ctr++) {
 120         vMoments(axis_ctr+1) += Coeff[axis_ctr+3][ctr]->TotalValue();
 121       }
 122     }
 123     return false;
 124   } else {
 125     return true;
 126   }
 127 }
 128
 129 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 130
 131 bool FGAerodynamics::Load(FGConfigFile* AC_cfg)
 132 {
 133   string token, axis;
 134
 135   AC_cfg->GetNextConfigLine();
 136
 137   while ((token = AC_cfg->GetValue()) != string("/AERODYNAMICS")) {
 138     if (token == "AXIS") {
 139       CoeffArray ca;
 140       axis = AC_cfg->GetValue("NAME");
 141       AC_cfg->GetNextConfigLine();
 142       while ((token = AC_cfg->GetValue()) != string("/AXIS")) {
 143         if( token == "COEFFICIENT" ) {
 144           ca.push_back( new FGCoefficient(FDMExec) );
 145           ca.back()->Load(AC_cfg);
 146         } else if ( token == "GROUP" ) {
 147           ca.push_back( new FGFactorGroup(FDMExec) );
 148           ca.back()->Load(AC_cfg);
 149         }
 150       }
 151       Coeff[AxisIdx[axis]] = ca;
 152       AC_cfg->GetNextConfigLine();
 153     }
 154   }
 155
 156   return true;
 157 }
 158
 159 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 160
 161 string FGAerodynamics::GetCoefficientStrings(void)
 162 {
 163   string CoeffStrings = "";
 164   bool firstime = true;
 165   unsigned int axis, sd;
 166
 167   for (axis = 0; axis < 6; axis++) {
 168     for (sd = 0; sd < Coeff[axis].size(); sd++) {
 169       if (firstime) {
 170         firstime = false;
 171       } else {
 172         CoeffStrings += ", ";
 173       }
 174       CoeffStrings += Coeff[axis][sd]->GetCoefficientStrings();
 175     }
 176   }
 177   return CoeffStrings;
 178 }
 179
 180 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 181
 182 string FGAerodynamics::GetCoefficientValues(void)
 183 {
 184   string SDValues = "";
 185   char buffer[10];
 186   bool firstime = true;
 187
 188   for (unsigned int axis = 0; axis < 6; axis++) {
 189     for (unsigned int sd = 0; sd < Coeff[axis].size(); sd++) {
 190       if (firstime) {
 191         firstime = false;
 192       } else {
 193         SDValues += ", ";
 194       }
 195       SDValues += Coeff[axis][sd]->GetCoefficientValues();
 196     }
 197   }
 198
 199   return SDValues;
 200 }
 201
 202 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 203
 204 double FGAerodynamics::GetLoD(void)
 205 {
 206   double LoD;
 207
 208   if (vFs(1) != 0.00) return vFs(3)/vFs(1);
 209   else                return 0.00;
 210 }
 211
 212 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 213
 214 void FGAerodynamics::Debug(void)
 215 {
 216     //TODO: Add your source code here
 217 }
 218