src/FDM/JSBSim/models/propulsion/FGEngine.cpp

   1 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   2
   3  Module:       FGEngine.cpp
   4  Author:       Jon Berndt
   5  Date started: 01/21/99
   6  Called by:    FGAircraft
   7
   8  ------------- Copyright (C) 1999  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 Lesser 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 Lesser General Public License for more details.
  18
  19  You should have received a copy of the GNU Lesser General Public License along with
  20  this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  21  Place - Suite 330, Boston, MA  02111-1307, USA.
  22
  23  Further information about the GNU Lesser General Public License can also be found on
  24  the world wide web at http://www.gnu.org.
  25
  26 FUNCTIONAL DESCRIPTION
  27 --------------------------------------------------------------------------------
  28 See header file.
  29
  30 HISTORY
  31 --------------------------------------------------------------------------------
  32 01/21/99   JSB   Created
  33 09/03/99   JSB   Changed Rocket thrust equation to correct -= Thrust instead of
  34                  += Thrust (thanks to Tony Peden)
  35
  36 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  37 INCLUDES
  38 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  39
  40 #ifdef FGFS
  41 #  include <simgear/compiler.h>
  42 #  ifdef SG_HAVE_STD_INCLUDES
  43 #    include <fstream>
  44 #  else
  45 #    include <fstream.h>
  46 #  endif
  47 #else
  48 #  if defined(sgi) && !defined(__GNUC__) && (_COMPILER_VERSION < 740)
  49 #    include <fstream.h>
  50 #  else
  51 #    include <fstream>
  52 #  endif
  53 #endif
  54
  55 #include "FGEngine.h"
  56 #include "FGTank.h"
  57 #include "FGPropeller.h"
  58 #include "FGNozzle.h"
  59 #include <input_output/FGXMLParse.h>
  60 #include <math/FGColumnVector3.h>
  61
  62 namespace JSBSim {
  63
  64 static const char *IdSrc = "$Id$";
  65 static const char *IdHdr = ID_ENGINE;
  66
  67 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  68 CLASS IMPLEMENTATION
  69 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  70
  71 FGEngine::FGEngine(FGFDMExec* exec, Element* engine_element, int engine_number)
  72                       : EngineNumber(engine_number)
  73 {
  74   Element* local_element;
  75   FGColumnVector3 location, orientation;
  76
  77   Name = "";
  78   Type = etUnknown;
  79   X = Y = Z = 0.0;
  80   EnginePitch = EngineYaw = 0.0;
  81   SLFuelFlowMax = SLOxiFlowMax = 0.0;
  82   MaxThrottle = 1.0;
  83   MinThrottle = 0.0;
  84
  85   ResetToIC(); // initialize dynamic terms
  86
  87   FDMExec = exec;
  88   State = FDMExec->GetState();
  89   Atmosphere = FDMExec->GetAtmosphere();
  90   FCS = FDMExec->GetFCS();
  91   Propulsion = FDMExec->GetPropulsion();
  92   Aircraft = FDMExec->GetAircraft();
  93   Propagate = FDMExec->GetPropagate();
  94   Auxiliary = FDMExec->GetAuxiliary();
  95
  96   PropertyManager = FDMExec->GetPropertyManager();
  97
  98   Name = engine_element->GetAttributeValue("name");
  99
 100 // Find and set engine location
 101
 102   local_element = engine_element->GetParent()->FindElement("location");
 103   if (local_element)  location = local_element->FindElementTripletConvertTo("IN");
 104   else      cerr << "No engine location found for this engine." << endl;
 105
 106   local_element = engine_element->GetParent()->FindElement("orient");
 107   if (local_element)  orientation = local_element->FindElementTripletConvertTo("RAD");
 108 //  else          cerr << "No engine orientation found for this engine." << endl;
 109 // Jon: The engine orientation has a default and is not normally used.
 110
 111   SetPlacement(location, orientation);
 112
 113   // Load thruster
 114   local_element = engine_element->GetParent()->FindElement("thruster");
 115   if (local_element) {
 116     if (!LoadThruster(local_element)) exit(-1);
 117   } else {
 118     cerr << "No thruster definition supplied with engine definition." << endl;
 119   }
 120
 121   // Load feed tank[s] references
 122   local_element = engine_element->GetParent()->FindElement("feed");
 123   if (local_element) {
 124     while (local_element) {
 125       AddFeedTank((int)local_element->GetDataAsNumber());
 126       local_element = engine_element->GetParent()->FindNextElement("feed");
 127     }
 128   } else {
 129     cerr << "No feed tank specified in engine definition." << endl;
 130   }
 131
 132   char property_name[80];
 133   snprintf(property_name, 80, "propulsion/engine[%d]/set-running", EngineNumber);
 134   PropertyManager->Tie( property_name, (FGEngine*)this, &FGEngine::GetRunning,
 135                                        &FGEngine::SetRunning );
 136
 137   Debug(0);
 138 }
 139
 140 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 141
 142 FGEngine::~FGEngine()
 143 {
 144   delete Thruster;
 145   Debug(1);
 146 }
 147
 148 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 149
 150 void FGEngine::ResetToIC(void)
 151 {
 152   Thrust = 0.0;
 153   Throttle = 0.0;
 154   Mixture = 1.0;
 155   Starter = false;
 156   FuelNeed = OxidizerNeed = 0.0;
 157   Starved = Running = Cranking = false;
 158   PctPower = 0.0;
 159   TrimMode = false;
 160   FuelFlow_gph = 0.0;
 161   FuelFlow_pph = 0.0;
 162   FuelFreeze = false;
 163 }
 164
 165 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 166 // This base class function should be called from within the
 167 // derived class' Calculate() function before any other calculations are done.
 168 // This base class method removes fuel from the fuel tanks as appropriate,
 169 // and sets the starved flag if necessary.
 170
 171 void FGEngine::ConsumeFuel(void)
 172 {
 173   if (FuelFreeze) return;
 174   if (TrimMode) return;
 175
 176   unsigned int i;
 177   double Fshortage, Oshortage, TanksWithFuel, TanksWithOxidizer;
 178   FGTank* Tank;
 179   bool haveOxTanks = false;
 180   Fshortage = Oshortage = TanksWithFuel = TanksWithOxidizer = 0.0;
 181
 182   // count how many assigned tanks have fuel
 183   for (i=0; i<SourceTanks.size(); i++) {
 184     Tank = Propulsion->GetTank(SourceTanks[i]);
 185     if (Tank->GetType() == FGTank::ttFUEL){
 186       if (Tank->GetContents() > 0.0) ++TanksWithFuel;
 187     } else if (Tank->GetType() == FGTank::ttOXIDIZER) {
 188       haveOxTanks = true;
 189       if (Tank->GetContents() > 0.0) ++TanksWithOxidizer;
 190     }
 191   }
 192   if (TanksWithFuel==0 || (haveOxTanks && TanksWithOxidizer==0)) {
 193     Starved = true;
 194     return;
 195   }
 196
 197   for (i=0; i<SourceTanks.size(); i++) {
 198     Tank = Propulsion->GetTank(SourceTanks[i]);
 199     if (Tank->GetType() == FGTank::ttFUEL) {
 200        Fshortage += Tank->Drain(CalcFuelNeed()/TanksWithFuel);
 201     } else if (Tank->GetType() == FGTank::ttOXIDIZER) {
 202        Oshortage += Tank->Drain(CalcOxidizerNeed()/TanksWithOxidizer);
 203     }
 204   }
 205
 206   if (Fshortage < 0.00 || Oshortage < 0.00) Starved = true;
 207   else Starved = false;
 208 }
 209
 210 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 211
 212 double FGEngine::CalcFuelNeed(void)
 213 {
 214   FuelNeed = SLFuelFlowMax*PctPower*State->Getdt()*Propulsion->GetRate();
 215   return FuelNeed;
 216 }
 217
 218 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 219
 220 double FGEngine::CalcOxidizerNeed(void)
 221 {
 222   OxidizerNeed = SLOxiFlowMax*PctPower*State->Getdt()*Propulsion->GetRate();
 223   return OxidizerNeed;
 224 }
 225
 226 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 227
 228 void FGEngine::SetPlacement(FGColumnVector3& location, FGColumnVector3& orientation)
 229 {
 230   X = location(eX);
 231   Y = location(eY);
 232   Z = location(eZ);
 233   EnginePitch = orientation(ePitch);
 234   EngineYaw = orientation (eYaw);
 235 }
 236
 237 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 238
 239 void FGEngine::AddFeedTank(int tkID)
 240 {
 241   SourceTanks.push_back(tkID);
 242 }
 243
 244 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 245
 246 FGColumnVector3& FGEngine::GetBodyForces(void)
 247 {
 248   return Thruster->GetBodyForces();
 249 }
 250
 251 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 252
 253 FGColumnVector3& FGEngine::GetMoments(void)
 254 {
 255   return Thruster->GetMoments();
 256 }
 257
 258 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 259
 260 bool FGEngine::LoadThruster(Element *thruster_element)
 261 {
 262   string token, fullpath, localpath;
 263   string thruster_filename, thruster_fullpathname, thrType;
 264   double P_Factor = 0, Sense = 0.0;
 265   string enginePath = FDMExec->GetEnginePath();
 266   string aircraftPath = FDMExec->GetFullAircraftPath();
 267   ifstream thruster_file;
 268   FGColumnVector3 location, orientation;
 269   string separator = "/";
 270
 271 # ifdef macintosh
 272     separator = ";";
 273 # endif
 274
 275   fullpath = enginePath + separator;
 276   localpath = aircraftPath + separator + "Engines" + separator;
 277
 278   thruster_filename = thruster_element->GetAttributeValue("file");
 279   if ( !thruster_filename.empty()) {
 280     thruster_fullpathname = fullpath + thruster_filename + ".xml";
 281     thruster_file.open(thruster_fullpathname.c_str());
 282     if ( !thruster_file.is_open()) {
 283       thruster_fullpathname = localpath + thruster_filename + ".xml";
 284       thruster_file.open(thruster_fullpathname.c_str());
 285       if ( !thruster_file.is_open()) {
 286         cerr << "Could not open thruster file: " << thruster_filename << ".xml" << endl;
 287         return false;
 288       } else {
 289         thruster_file.close();
 290       }
 291     } else {
 292       thruster_file.close();
 293     }
 294   } else {
 295     cerr << "No thruster filename given." << endl;
 296     return false;
 297   }
 298
 299   document = LoadXMLDocument(thruster_fullpathname);
 300   document->SetParent(thruster_element);
 301
 302   thrType = document->GetName();
 303
 304   if (thrType == "propeller") {
 305     Thruster = new FGPropeller(FDMExec, document, EngineNumber);
 306   } else if (thrType == "nozzle") {
 307     Thruster = new FGNozzle(FDMExec, document, EngineNumber);
 308   } else if (thrType == "direct") {
 309     Thruster = new FGThruster( FDMExec, document, EngineNumber);
 310   }
 311
 312   Thruster->SetdeltaT(State->Getdt() * Propulsion->GetRate());
 313
 314   Debug(2);
 315   return true;
 316 }
 317
 318 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 319 //    The bitmasked value choices are as follows:
 320 //    unset: In this case (the default) JSBSim would only print
 321 //       out the normally expected messages, essentially echoing
 322 //       the config files as they are read. If the environment
 323 //       variable is not set, debug_lvl is set to 1 internally
 324 //    0: This requests JSBSim not to output any messages
 325 //       whatsoever.
 326 //    1: This value explicity requests the normal JSBSim
 327 //       startup messages
 328 //    2: This value asks for a message to be printed out when
 329 //       a class is instantiated
 330 //    4: When this value is set, a message is displayed when a
 331 //       FGModel object executes its Run() method
 332 //    8: When this value is set, various runtime state variables
 333 //       are printed out periodically
 334 //    16: When set various parameters are sanity checked and
 335 //       a message is printed out when they go out of bounds
 336
 337 void FGEngine::Debug(int from)
 338 {
 339   if (debug_lvl <= 0) return;
 340
 341   if (debug_lvl & 1) { // Standard console startup message output
 342     if (from == 0) { // Constructor
 343
 344     }
 345     if (from == 2) { // After thruster loading
 346       cout << "      X = " << Thruster->GetLocationX() << endl;
 347       cout << "      Y = " << Thruster->GetLocationY() << endl;
 348       cout << "      Z = " << Thruster->GetLocationZ() << endl;
 349       cout << "      Pitch = " << radtodeg*Thruster->GetAnglesToBody(ePitch) << " degrees" << endl;
 350       cout << "      Yaw = " << radtodeg*Thruster->GetAnglesToBody(eYaw) << " degrees" << endl;
 351     }
 352   }
 353   if (debug_lvl & 2 ) { // Instantiation/Destruction notification
 354     if (from == 0) cout << "Instantiated: FGEngine" << endl;
 355     if (from == 1) cout << "Destroyed:    FGEngine" << endl;
 356   }
 357   if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
 358   }
 359   if (debug_lvl & 8 ) { // Runtime state variables
 360   }
 361   if (debug_lvl & 16) { // Sanity checking
 362   }
 363   if (debug_lvl & 64) {
 364     if (from == 0) { // Constructor
 365       cout << IdSrc << endl;
 366       cout << IdHdr << endl;
 367     }
 368   }
 369 }
 370 }