src/FDM/JSBSim/FGGroundReactions.cpp

   1 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   2
   3  Module:       FGGroundReactions.cpp
   4  Author:       Jon S. Berndt
   5  Date started: 09/13/00
   6  Purpose:      Encapsulates the ground reaction 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
  34 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  35 INCLUDES
  36 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  37
  38 #include "FGGroundReactions.h"
  39 #include "FGPropertyManager.h"
  40
  41 static const char *IdSrc = "$Id$";
  42 static const char *IdHdr = ID_GROUNDREACTIONS;
  43
  44 #if defined (__APPLE__)
  45 /* Not all systems have the gcvt function */
  46 inline char* gcvt (double value, int ndigits, char *buf) {
  47     /* note that this is not exactly what gcvt is supposed to do! */
  48     snprintf (buf, ndigits+1, "%f", value);
  49     return buf;
  50 }
  51 #endif
  52
  53 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  54 CLASS IMPLEMENTATION
  55 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  56
  57
  58 FGGroundReactions::FGGroundReactions(FGFDMExec* fgex) : FGModel(fgex)
  59 {
  60   Name = "FGGroundReactions";
  61
  62   bind();
  63
  64   Debug(0);
  65 }
  66
  67 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  68
  69 FGGroundReactions::~FGGroundReactions(void)
  70 {
  71   unbind();
  72
  73   Debug(1);
  74 }
  75
  76 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  77
  78 bool FGGroundReactions::Run(void)
  79 {
  80   if (!FGModel::Run()) {
  81     vForces.InitMatrix();
  82     vMoments.InitMatrix();
  83
  84     // Only execute gear force code below 300 feet
  85     if ( Position->GetDistanceAGL() < 300.0 ) {
  86       vector <FGLGear>::iterator iGear = lGear.begin();
  87       // Sum forces and moments for all gear, here.
  88       // Some optimizations may be made here - or rather in the gear code itself.
  89       // The gear ::Run() method is called several times - once for each gear.
  90       // Perhaps there is some commonality for things which only need to be
  91       // calculated once.
  92       while (iGear != lGear.end()) {
  93         vForces  += iGear->Force();
  94         vMoments += iGear->Moment();
  95         iGear++;
  96       }
  97
  98     } else {
  99       // Crash Routine
 100     }
 101
 102     return false;
 103   } else {
 104     return true;
 105   }
 106 }
 107
 108 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 109
 110 bool FGGroundReactions::Load(FGConfigFile* AC_cfg)
 111 {
 112   string token;
 113
 114   AC_cfg->GetNextConfigLine();
 115
 116   while ((token = AC_cfg->GetValue()) != string("/UNDERCARRIAGE")) {
 117     lGear.push_back(FGLGear(AC_cfg, FDMExec));
 118   }
 119
 120   return true;
 121 }
 122
 123 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 124
 125 string FGGroundReactions::GetGroundReactionStrings(void)
 126 {
 127   string GroundReactionStrings = "";
 128   bool firstime = true;
 129
 130   for (unsigned int i=0;i<lGear.size();i++) {
 131     if (!firstime) GroundReactionStrings += ", ";
 132     GroundReactionStrings += (lGear[i].GetName() + "_WOW, ");
 133     GroundReactionStrings += (lGear[i].GetName() + "_stroke, ");
 134     GroundReactionStrings += (lGear[i].GetName() + "_strokeVel, ");
 135     GroundReactionStrings += (lGear[i].GetName() + "_CompressForce, ");
 136     GroundReactionStrings += (lGear[i].GetName() + "_WhlSideForce, ");
 137     GroundReactionStrings += (lGear[i].GetName() + "_WhlRollForce, ");
 138     GroundReactionStrings += (lGear[i].GetName() + "_BodyXForce, ");
 139     GroundReactionStrings += (lGear[i].GetName() + "_BodyYForce, ");
 140     GroundReactionStrings += (lGear[i].GetName() + "_WhlSlipDegrees");
 141
 142     firstime = false;
 143   }
 144
 145   return GroundReactionStrings;
 146 }
 147
 148 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 149
 150 string FGGroundReactions::GetGroundReactionValues(void)
 151 {
 152   char buff[20];
 153   string GroundReactionValues = "";
 154
 155   bool firstime = true;
 156
 157   for (unsigned int i=0;i<lGear.size();i++) {
 158     if (!firstime) GroundReactionValues += ", ";
 159     GroundReactionValues += string( lGear[i].GetWOW()?"1":"0" ) + ", ";
 160     GroundReactionValues += (string(gcvt(lGear[i].GetCompLen(),    5, buff)) + ", ");
 161     GroundReactionValues += (string(gcvt(lGear[i].GetCompVel(),    6, buff)) + ", ");
 162     GroundReactionValues += (string(gcvt(lGear[i].GetCompForce(), 10, buff)) + ", ");
 163     GroundReactionValues += (string(gcvt(lGear[i].GetWheelSideForce(), 6, buff)) + ", ");
 164     GroundReactionValues += (string(gcvt(lGear[i].GetWheelRollForce(), 6, buff)) + ", ");
 165     GroundReactionValues += (string(gcvt(lGear[i].GetBodyXForce(), 6, buff)) + ", ");
 166     GroundReactionValues += (string(gcvt(lGear[i].GetBodyYForce(), 6, buff)) + ", ");
 167     GroundReactionValues += (string(gcvt(lGear[i].GetWheelSlipAngle(), 6, buff)));
 168
 169     firstime = false;
 170   }
 171
 172   return GroundReactionValues;
 173 }
 174
 175 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 176
 177 void FGGroundReactions::bind(void)
 178 {
 179   typedef double (FGGroundReactions::*PMF)(int) const;
 180   PropertyManager->Tie("gear/num-units", this,
 181                        &FGGroundReactions::GetNumGearUnits);
 182   PropertyManager->Tie("moments/l-gear-lbsft", this,1,
 183                        (PMF)&FGGroundReactions::GetMoments);
 184   PropertyManager->Tie("moments/m-gear-lbsft", this,2,
 185                        (PMF)&FGGroundReactions::GetMoments);
 186   PropertyManager->Tie("moments/n-gear-lbsft", this,3,
 187                        (PMF)&FGGroundReactions::GetMoments);
 188   PropertyManager->Tie("forces/fbx-gear-lbs", this,1,
 189                        (PMF)&FGGroundReactions::GetForces);
 190   PropertyManager->Tie("forces/fby-gear-lbs", this,2,
 191                        (PMF)&FGGroundReactions::GetForces);
 192   PropertyManager->Tie("forces/fbz-gear-lbs", this,3,
 193                        (PMF)&FGGroundReactions::GetForces);
 194 }
 195
 196 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 197
 198 void FGGroundReactions::unbind(void)
 199 {
 200   PropertyManager->Untie("gear/num-units");
 201   PropertyManager->Untie("moments/l-gear-lbsft");
 202   PropertyManager->Untie("moments/m-gear-lbsft");
 203   PropertyManager->Untie("moments/n-gear-lbsft");
 204   PropertyManager->Untie("forces/fbx-gear-lbs");
 205   PropertyManager->Untie("forces/fby-gear-lbs");
 206   PropertyManager->Untie("forces/fbz-gear-lbs");
 207 }
 208
 209 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 210 //    The bitmasked value choices are as follows:
 211 //    unset: In this case (the default) JSBSim would only print
 212 //       out the normally expected messages, essentially echoing
 213 //       the config files as they are read. If the environment
 214 //       variable is not set, debug_lvl is set to 1 internally
 215 //    0: This requests JSBSim not to output any messages
 216 //       whatsoever.
 217 //    1: This value explicity requests the normal JSBSim
 218 //       startup messages
 219 //    2: This value asks for a message to be printed out when
 220 //       a class is instantiated
 221 //    4: When this value is set, a message is displayed when a
 222 //       FGModel object executes its Run() method
 223 //    8: When this value is set, various runtime state variables
 224 //       are printed out periodically
 225 //    16: When set various parameters are sanity checked and
 226 //       a message is printed out when they go out of bounds
 227
 228 void FGGroundReactions::Debug(int from)
 229 {
 230   if (debug_lvl <= 0) return;
 231
 232   if (debug_lvl & 1) { // Standard console startup message output
 233     if (from == 0) { // Constructor
 234
 235     }
 236   }
 237   if (debug_lvl & 2 ) { // Instantiation/Destruction notification
 238     if (from == 0) cout << "Instantiated: FGGroundReactions" << endl;
 239     if (from == 1) cout << "Destroyed:    FGGroundReactions" << endl;
 240   }
 241   if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
 242   }
 243   if (debug_lvl & 8 ) { // Runtime state variables
 244   }
 245   if (debug_lvl & 16) { // Sanity checking
 246   }
 247   if (debug_lvl & 64) {
 248     if (from == 0) { // Constructor
 249       cout << IdSrc << endl;
 250       cout << IdHdr << endl;
 251     }
 252   }
 253 }
 254