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This is the looping fix.
[flightgear.git] / 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 (jon@jsbsim.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 #include "FGEngine.h"
41 #include "FGTank.h"
42 #include "FGPropeller.h"
43 #include "FGNozzle.h"
44 #include "input_output/FGXMLParse.h"
45 #include "math/FGColumnVector3.h"
46 #include <fstream>
47
48 namespace JSBSim {
49
50 static const char *IdSrc = "$Id$";
51 static const char *IdHdr = ID_ENGINE;
52
53 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
54 CLASS IMPLEMENTATION
55 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
56
57 FGEngine::FGEngine(FGFDMExec* exec, Element* engine_element, int engine_number)
58                       : EngineNumber(engine_number)
59 {
60   Element* local_element;
61   FGColumnVector3 location, orientation;
62
63   Name = "";
64   Type = etUnknown;
65   X = Y = Z = 0.0;
66   EnginePitch = EngineYaw = 0.0;
67   SLFuelFlowMax = 0.0;
68   MaxThrottle = 1.0;
69   MinThrottle = 0.0;
70   unsigned int i;
71
72   ResetToIC(); // initialize dynamic terms
73
74   FDMExec = exec;
75   State = FDMExec->GetState();
76   Atmosphere = FDMExec->GetAtmosphere();
77   FCS = FDMExec->GetFCS();
78   Propulsion = FDMExec->GetPropulsion();
79   Aircraft = FDMExec->GetAircraft();
80   Propagate = FDMExec->GetPropagate();
81   Auxiliary = FDMExec->GetAuxiliary();
82
83   PropertyManager = FDMExec->GetPropertyManager();
84
85   Name = engine_element->GetAttributeValue("name");
86
87 // Find and set engine location
88
89   local_element = engine_element->GetParent()->FindElement("location");
90   if (local_element)  location = local_element->FindElementTripletConvertTo("IN");
91   else      cerr << "No engine location found for this engine." << endl;
92
93   local_element = engine_element->GetParent()->FindElement("orient");
94   if (local_element)  orientation = local_element->FindElementTripletConvertTo("RAD");
95 //  else          cerr << "No engine orientation found for this engine." << endl;
96 // Jon: The engine orientation has a default and is not normally used.
97
98   SetPlacement(location, orientation);
99
100   // Load thruster
101   local_element = engine_element->GetParent()->FindElement("thruster");
102   if (local_element) {
103     if (!LoadThruster(local_element)) exit(-1);
104   } else {
105     cerr << "No thruster definition supplied with engine definition." << endl;
106   }
107
108   // Build and initialize the feed tank vector.
109   for (i=0; i<(Propulsion->GetNumTanks()); i++) {
110     SourceTanks.push_back(0);
111   }
112
113   // Load feed tank[s] references
114   local_element = engine_element->GetParent()->FindElement("feed");
115   if (local_element) {
116     while (local_element) {
117       int tankID = (int)local_element->GetDataAsNumber();
118       AddFeedTank( tankID , Propulsion->GetTank(tankID)->GetPriority());
119       local_element = engine_element->GetParent()->FindNextElement("feed");
120     }
121   } else {
122     cerr << "No feed tank specified in engine definition." << endl;
123   }
124
125   string property_name, base_property_name;
126   base_property_name = CreateIndexedPropertyName("propulsion/engine", EngineNumber);
127
128   property_name = base_property_name + "/set-running";
129   PropertyManager->Tie( property_name.c_str(), this, &FGEngine::GetRunning, &FGEngine::SetRunning );
130   property_name = base_property_name + "/thrust-lbs";
131   PropertyManager->Tie( property_name.c_str(), Thruster, &FGThruster::GetThrust);
132   property_name = base_property_name + "/fuel-flow-rate-pps";
133   PropertyManager->Tie( property_name.c_str(), this, &FGEngine::GetFuelFlowRate);
134
135   Debug(0);
136 }
137
138 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
139
140 FGEngine::~FGEngine()
141 {
142   delete Thruster;
143   Debug(1);
144 }
145
146 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
147
148 void FGEngine::ResetToIC(void)
149 {
150   Throttle = 0.0;
151   Mixture = 1.0;
152   Starter = false;
153   FuelExpended = 0.0;
154   Starved = Running = Cranking = false;
155   PctPower = 0.0;
156   TrimMode = false;
157   FuelFlow_gph = 0.0;
158   FuelFlow_pph = 0.0;
159   FuelFreeze = false;
160 }
161
162 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
163 // This base class function should be called from within the
164 // derived class' Calculate() function before any other calculations are done.
165 // This base class method removes fuel from the fuel tanks as appropriate,
166 // and sets the starved flag if necessary.
167 // This version of the fuel consumption code should never see an oxidizer tank.
168
169 void FGEngine::ConsumeFuel(void)
170 {
171   if (FuelFreeze) return;
172   if (TrimMode) return;
173
174   unsigned int i;
175   double Fshortage, FuelNeeded;
176   FGTank* Tank;
177   unsigned int TanksWithFuel = 0;
178   Fshortage = FuelNeeded = 0.0;
179   double FuelToBurn;
180   unsigned int CurrentPriority = 1;
181   vector <int> FeedList;
182   Starved = false;
183
184   FuelToBurn = CalcFuelNeed();
185
186   while (FuelToBurn > 0.0) {
187
188     // Count how many fuel tanks with the current priority level have fuel.
189     // If none, then try next lower priority.  Build the feed list.
190     while ((TanksWithFuel == 0.0) && (CurrentPriority <= Propulsion->GetNumTanks())) {
191       for (i=0; i<Propulsion->GetNumTanks(); i++) {
192         if (SourceTanks[i] != 0) {
193           Tank = Propulsion->GetTank(i);
194           if (Tank->GetType() == FGTank::ttFUEL) {
195             if ((Tank->GetContents() > 0.0) && ((unsigned int)Tank->GetPriority() == CurrentPriority)) {
196                ++TanksWithFuel;
197                FeedList.push_back(i);
198              } 
199           } else {
200              cerr << "No oxidizer tanks should be used for this engine type." << endl;
201           }
202         }
203       }
204       if (TanksWithFuel == 0) CurrentPriority++;
205     }
206
207     // No fuel found at any priority!
208     if (TanksWithFuel == 0) {
209       Starved = true;
210       return;
211     }
212
213     // Remove equal amount of fuel from each feed tank.  
214     FuelNeeded = FuelToBurn/TanksWithFuel;
215     for (i=0; i<FeedList.size(); i++) {
216       Tank = Propulsion->GetTank(FeedList[i]);
217       Tank->Drain(FuelNeeded); 
218       FuelToBurn -= FuelNeeded;
219     }
220
221     // check if we were not able to burn all the fuel we needed to at this priority level
222     if (FuelToBurn > 0.0) {
223       CurrentPriority++;
224       TanksWithFuel = 0;
225       FeedList.clear();
226     }
227  
228   }  // while
229 }
230
231 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
232
233 double FGEngine::CalcFuelNeed(void)
234 {
235   double dT = State->Getdt()*Propulsion->GetRate();
236   FuelFlowRate = SLFuelFlowMax*PctPower;
237   FuelExpended = FuelFlowRate*dT;
238   return FuelExpended;
239 }
240
241 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
242
243 void FGEngine::SetPlacement(FGColumnVector3& location, FGColumnVector3& orientation)
244 {
245   X = location(eX);
246   Y = location(eY);
247   Z = location(eZ);
248   EnginePitch = orientation(ePitch);
249   EngineYaw = orientation (eYaw);
250 }
251
252 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
253
254 void FGEngine::AddFeedTank(int tkID, int priority)
255 {
256   SourceTanks[tkID] = priority;
257 }
258
259 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
260
261 FGColumnVector3& FGEngine::GetBodyForces(void)
262 {
263   return Thruster->GetBodyForces();
264 }
265
266 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
267
268 FGColumnVector3& FGEngine::GetMoments(void)
269 {
270   return Thruster->GetMoments();
271 }
272
273 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
274
275 bool FGEngine::LoadThruster(Element *thruster_element)
276 {
277   string token, fullpath, localpath;
278   string thruster_filename, thruster_fullpathname, thrType;
279   string enginePath = FDMExec->GetEnginePath();
280   string aircraftPath = FDMExec->GetFullAircraftPath();
281   ifstream thruster_file;
282   FGColumnVector3 location, orientation;
283   string separator = "/";
284
285   fullpath = enginePath + separator;
286   localpath = aircraftPath + separator + "Engines" + separator;
287
288   thruster_filename = thruster_element->GetAttributeValue("file");
289   if ( !thruster_filename.empty()) {
290     thruster_fullpathname = fullpath + thruster_filename + ".xml";
291     thruster_file.open(thruster_fullpathname.c_str());
292     if ( !thruster_file.is_open()) {
293       thruster_fullpathname = localpath + thruster_filename + ".xml";
294       thruster_file.open(thruster_fullpathname.c_str());
295       if ( !thruster_file.is_open()) {
296         cerr << "Could not open thruster file: " << thruster_filename << ".xml" << endl;
297         return false;
298       } else {
299         thruster_file.close();
300       }
301     } else {
302       thruster_file.close();
303     }
304   } else {
305     cerr << "No thruster filename given." << endl;
306     return false;
307   }
308
309   document = LoadXMLDocument(thruster_fullpathname);
310   document->SetParent(thruster_element);
311
312   thrType = document->GetName();
313
314   if (thrType == "propeller") {
315     Thruster = new FGPropeller(FDMExec, document, EngineNumber);
316   } else if (thrType == "nozzle") {
317     Thruster = new FGNozzle(FDMExec, document, EngineNumber);
318   } else if (thrType == "direct") {
319     Thruster = new FGThruster( FDMExec, document, EngineNumber);
320   }
321
322   Thruster->SetdeltaT(State->Getdt() * Propulsion->GetRate());
323
324   Debug(2);
325   return true;
326 }
327
328 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
329 //    The bitmasked value choices are as follows:
330 //    unset: In this case (the default) JSBSim would only print
331 //       out the normally expected messages, essentially echoing
332 //       the config files as they are read. If the environment
333 //       variable is not set, debug_lvl is set to 1 internally
334 //    0: This requests JSBSim not to output any messages
335 //       whatsoever.
336 //    1: This value explicity requests the normal JSBSim
337 //       startup messages
338 //    2: This value asks for a message to be printed out when
339 //       a class is instantiated
340 //    4: When this value is set, a message is displayed when a
341 //       FGModel object executes its Run() method
342 //    8: When this value is set, various runtime state variables
343 //       are printed out periodically
344 //    16: When set various parameters are sanity checked and
345 //       a message is printed out when they go out of bounds
346
347 void FGEngine::Debug(int from)
348 {
349   if (debug_lvl <= 0) return;
350
351   if (debug_lvl & 1) { // Standard console startup message output
352     if (from == 0) { // Constructor
353
354     }
355     if (from == 2) { // After thruster loading
356       cout << "      X = " << Thruster->GetLocationX() << endl;
357       cout << "      Y = " << Thruster->GetLocationY() << endl;
358       cout << "      Z = " << Thruster->GetLocationZ() << endl;
359       cout << "      Pitch = " << radtodeg*Thruster->GetAnglesToBody(ePitch) << " degrees" << endl;
360       cout << "      Yaw = " << radtodeg*Thruster->GetAnglesToBody(eYaw) << " degrees" << endl;
361     }
362   }
363   if (debug_lvl & 2 ) { // Instantiation/Destruction notification
364     if (from == 0) cout << "Instantiated: FGEngine" << endl;
365     if (from == 1) cout << "Destroyed:    FGEngine" << endl;
366   }
367   if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
368   }
369   if (debug_lvl & 8 ) { // Runtime state variables
370   }
371   if (debug_lvl & 16) { // Sanity checking
372   }
373   if (debug_lvl & 64) {
374     if (from == 0) { // Constructor
375       cout << IdSrc << endl;
376       cout << IdHdr << endl;
377     }
378   }
379 }
380 }