1 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
3 Module: FGAuxiliary.cpp
4 Author: Tony Peden, Jon Berndt
6 Purpose: Calculates additional parameters needed by the visual system, etc.
9 ------------- Copyright (C) 1999 Jon S. Berndt (jon@jsbsim.org) -------------
11 This program is free software; you can redistribute it and/or modify it under
12 the terms of the GNU Lesser General Public License as published by the Free Software
13 Foundation; either version 2 of the License, or (at your option) any later
16 This program is distributed in the hope that it will be useful, but WITHOUT
17 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
18 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
21 You should have received a copy of the GNU Lesser General Public License along with
22 this program; if not, write to the Free Software Foundation, Inc., 59 Temple
23 Place - Suite 330, Boston, MA 02111-1307, USA.
25 Further information about the GNU Lesser General Public License can also be found on
26 the world wide web at http://www.gnu.org.
28 FUNCTIONAL DESCRIPTION
29 --------------------------------------------------------------------------------
30 This class calculates various auxiliary parameters.
33 Anderson, John D. "Introduction to Flight", 3rd Edition, McGraw-Hill, 1989
36 --------------------------------------------------------------------------------
39 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
41 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
43 #include "FGAuxiliary.h"
44 #include "FGAerodynamics.h"
45 #include "FGPropagate.h"
46 #include "FGAtmosphere.h"
47 #include <FGFDMExec.h>
48 #include "FGAircraft.h"
49 #include "FGInertial.h"
50 #include "FGExternalReactions.h"
51 #include "FGBuoyantForces.h"
52 #include "FGGroundReactions.h"
53 #include "FGPropulsion.h"
54 #include <input_output/FGPropertyManager.h>
58 static const char *IdSrc = "$Id$";
59 static const char *IdHdr = ID_AUXILIARY;
61 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
63 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
66 FGAuxiliary::FGAuxiliary(FGFDMExec* fdmex) : FGModel(fdmex)
69 vcas = veas = pt = tat = 0;
78 gamma = Vt = Vground = 0.0;
82 hoverbmac = hoverbcg = 0.0;
83 tatc = RankineToCelsius(tat);
85 vPilotAccel.InitMatrix();
86 vPilotAccelN.InitMatrix();
87 vToEyePt.InitMatrix();
88 vAeroPQR.InitMatrix();
89 vEulerRates.InitMatrix();
96 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
98 bool FGAuxiliary::InitModel(void)
100 if (!FGModel::InitModel()) return false;
102 vcas = veas = pt = tat = 0;
110 gamma = Vt = Vground = 0.0;
113 seconds_in_day = 0.0;
114 hoverbmac = hoverbcg = 0.0;
116 vPilotAccel.InitMatrix();
117 vPilotAccelN.InitMatrix();
118 vToEyePt.InitMatrix();
119 vAeroPQR.InitMatrix();
120 vEulerRates.InitMatrix();
125 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
127 FGAuxiliary::~FGAuxiliary()
132 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
134 bool FGAuxiliary::Run()
138 if (FGModel::Run()) return true; // return true if error returned from base class
139 if (FDMExec->Holding()) return false;
141 const FGColumnVector3& vPQR = Propagate->GetPQR();
142 const FGColumnVector3& vUVW = Propagate->GetUVW();
143 const FGColumnVector3& vUVWdot = Propagate->GetUVWdot();
144 const FGColumnVector3& vVel = Propagate->GetVel();
146 p = Atmosphere->GetPressure();
147 rhosl = Atmosphere->GetDensitySL();
148 psl = Atmosphere->GetPressureSL();
149 sat = Atmosphere->GetTemperature();
153 double cTht = Propagate->GetCosEuler(eTht);
154 double sTht = Propagate->GetSinEuler(eTht);
155 double cPhi = Propagate->GetCosEuler(ePhi);
156 double sPhi = Propagate->GetSinEuler(ePhi);
158 vEulerRates(eTht) = vPQR(eQ)*cPhi - vPQR(eR)*sPhi;
160 vEulerRates(ePsi) = (vPQR(eQ)*sPhi + vPQR(eR)*cPhi)/cTht;
161 vEulerRates(ePhi) = vPQR(eP) + vEulerRates(ePsi)*sTht;
164 // 12/16/2005, JSB: For ground handling purposes, at this time, let's ramp
165 // in the effects of wind from 10 fps to 30 fps when there is weight on the
166 // landing gear wheels.
168 if (GroundReactions->GetWOW() && vUVW(eU) < 10) {
171 } else if (GroundReactions->GetWOW() && vUVW(eU) < 30) {
172 double factor = (vUVW(eU) - 10.0)/20.0;
173 vAeroPQR = vPQR - factor*Atmosphere->GetTurbPQR();
174 vAeroUVW = vUVW - factor*Propagate->GetTl2b()*Atmosphere->GetTotalWindNED();
176 FGColumnVector3 wind = Propagate->GetTl2b()*Atmosphere->GetTotalWindNED();
177 vAeroPQR = vPQR - Atmosphere->GetTurbPQR();
178 vAeroUVW = vUVW - wind;
181 Vt = vAeroUVW.Magnitude();
183 if (vAeroUVW(eW) != 0.0)
184 alpha = vAeroUVW(eU)*vAeroUVW(eU) > 0.0 ? atan2(vAeroUVW(eW), vAeroUVW(eU)) : 0.0;
185 if (vAeroUVW(eV) != 0.0)
186 beta = vAeroUVW(eU)*vAeroUVW(eU)+vAeroUVW(eW)*vAeroUVW(eW) > 0.0 ? atan2(vAeroUVW(eV),
187 sqrt(vAeroUVW(eU)*vAeroUVW(eU) + vAeroUVW(eW)*vAeroUVW(eW))) : 0.0;
189 double mUW = (vAeroUVW(eU)*vAeroUVW(eU) + vAeroUVW(eW)*vAeroUVW(eW));
191 if (vAeroUVW(eU) != 0.0)
192 signU = vAeroUVW(eU)/fabs(vAeroUVW(eU));
194 if ( (mUW == 0.0) || (Vt == 0.0) ) {
198 adot = (vAeroUVW(eU)*vUVWdot(eW) - vAeroUVW(eW)*vUVWdot(eU))/mUW;
199 bdot = (signU*mUW*vUVWdot(eV) - vAeroUVW(eV)*(vAeroUVW(eU)*vUVWdot(eU)
200 + vAeroUVW(eW)*vUVWdot(eW)))/(Vt*Vt*sqrt(mUW));
203 alpha = beta = adot = bdot = 0;
206 Re = Vt * Aircraft->Getcbar() / Atmosphere->GetKinematicViscosity();
208 qbar = 0.5*Atmosphere->GetDensity()*Vt*Vt;
209 qbarUW = 0.5*Atmosphere->GetDensity()*(vAeroUVW(eU)*vAeroUVW(eU) + vAeroUVW(eW)*vAeroUVW(eW));
210 qbarUV = 0.5*Atmosphere->GetDensity()*(vAeroUVW(eU)*vAeroUVW(eU) + vAeroUVW(eV)*vAeroUVW(eV));
211 Mach = Vt / Atmosphere->GetSoundSpeed();
212 MachU = vMachUVW(eU) = vAeroUVW(eU) / Atmosphere->GetSoundSpeed();
213 vMachUVW(eV) = vAeroUVW(eV) / Atmosphere->GetSoundSpeed();
214 vMachUVW(eW) = vAeroUVW(eW) / Atmosphere->GetSoundSpeed();
218 Vground = sqrt( vVel(eNorth)*vVel(eNorth) + vVel(eEast)*vVel(eEast) );
220 psigt = atan2(vVel(eEast), vVel(eNorth));
221 if (psigt < 0.0) psigt += 2*M_PI;
222 gamma = atan2(-vVel(eDown), Vground);
224 tat = sat*(1 + 0.2*Mach*Mach); // Total Temperature, isentropic flow
225 tatc = RankineToCelsius(tat);
227 if (MachU < 1) { // Calculate total pressure assuming isentropic flow
228 pt = p*pow((1 + 0.2*MachU*MachU),3.5);
230 // Use Rayleigh pitot tube formula for normal shock in front of pitot tube
231 B = 5.76*MachU*MachU/(5.6*MachU*MachU - 0.8);
232 D = (2.8*MachU*MachU-0.4)*0.4167;
236 A = pow(((pt-p)/psl+1),0.28571);
238 vcas = sqrt(7*psl/rhosl*(A-1));
239 veas = sqrt(2*qbar/rhosl);
244 vPilotAccel.InitMatrix();
246 vAircraftAccel = Aerodynamics->GetForces()
247 + Propulsion->GetForces()
248 + GroundReactions->GetForces()
249 + ExternalReactions->GetForces()
250 + BuoyantForces->GetForces();
252 vAircraftAccel /= MassBalance->GetMass();
253 // Nz is Acceleration in "g's", along normal axis (-Z body axis)
254 Nz = -vAircraftAccel(eZ)/Inertial->gravity();
255 vToEyePt = MassBalance->StructuralToBody(Aircraft->GetXYZep());
256 vPilotAccel = vAircraftAccel + Propagate->GetPQRdot() * vToEyePt;
257 vPilotAccel += vPQR * (vPQR * vToEyePt);
259 // The line below handles low velocity (and on-ground) cases, basically
260 // representing the opposite of the force that the landing gear would
261 // exert on the ground (which is just the total weight). This eliminates
262 // any jitter that could be introduced by the landing gear. Theoretically,
263 // this branch could be eliminated, with a penalty of having a short
264 // transient at startup (lasting only a fraction of a second).
265 vPilotAccel = Propagate->GetTl2b() * FGColumnVector3( 0.0, 0.0, -Inertial->gravity() );
266 Nz = -vPilotAccel(eZ)/Inertial->gravity();
269 vPilotAccelN = vPilotAccel/Inertial->gravity();
272 const FGLocation& vLocation = Propagate->GetLocation();
273 FGColumnVector3 vrpStructural = Aircraft->GetXYZvrp();
274 FGColumnVector3 vrpBody = MassBalance->StructuralToBody( vrpStructural );
275 FGColumnVector3 vrpLocal = Propagate->GetTb2l() * vrpBody;
276 vLocationVRP = vLocation.LocalToLocation( vrpLocal );
278 // Recompute some derived values now that we know the dependent parameters values ...
279 hoverbcg = Propagate->GetDistanceAGL() / Aircraft->GetWingSpan();
281 FGColumnVector3 vMac = Propagate->GetTb2l()*MassBalance->StructuralToBody(Aircraft->GetXYZrp());
282 hoverbmac = (Propagate->GetDistanceAGL() + vMac(3)) / Aircraft->GetWingSpan();
284 // when all model are executed,
285 // please calculate the distance from the initial point
287 CalculateRelativePosition();
292 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
294 // A positive headwind is blowing with you, a negative headwind is blowing against you.
295 // psi is the direction the wind is blowing *towards*.
297 double FGAuxiliary::GetHeadWind(void) const
301 psiw = Atmosphere->GetWindPsi();
302 vw = Atmosphere->GetTotalWindNED().Magnitude();
304 return vw*cos(psiw - Propagate->GetEuler(ePsi));
307 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
309 // A positive crosswind is blowing towards the right (from teh perspective of the
310 // pilot). A negative crosswind is blowing towards the -Y direction (left).
311 // psi is the direction the wind is blowing *towards*.
313 double FGAuxiliary::GetCrossWind(void) const
317 psiw = Atmosphere->GetWindPsi();
318 vw = Atmosphere->GetTotalWindNED().Magnitude();
320 return vw*sin(psiw - Propagate->GetEuler(ePsi));
323 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
325 void FGAuxiliary::bind(void)
327 typedef double (FGAuxiliary::*PMF)(int) const;
328 typedef double (FGAuxiliary::*PF)(void) const;
329 PropertyManager->Tie("propulsion/tat-r", this, &FGAuxiliary::GetTotalTemperature);
330 PropertyManager->Tie("propulsion/tat-c", this, &FGAuxiliary::GetTAT_C);
331 PropertyManager->Tie("propulsion/pt-lbs_sqft", this, &FGAuxiliary::GetTotalPressure);
332 PropertyManager->Tie("velocities/vc-fps", this, &FGAuxiliary::GetVcalibratedFPS);
333 PropertyManager->Tie("velocities/vc-kts", this, &FGAuxiliary::GetVcalibratedKTS);
334 PropertyManager->Tie("velocities/ve-fps", this, &FGAuxiliary::GetVequivalentFPS);
335 PropertyManager->Tie("velocities/ve-kts", this, &FGAuxiliary::GetVequivalentKTS);
336 PropertyManager->Tie("velocities/machU", this, &FGAuxiliary::GetMachU);
337 PropertyManager->Tie("velocities/p-aero-rad_sec", this, eX, (PMF)&FGAuxiliary::GetAeroPQR);
338 PropertyManager->Tie("velocities/q-aero-rad_sec", this, eY, (PMF)&FGAuxiliary::GetAeroPQR);
339 PropertyManager->Tie("velocities/r-aero-rad_sec", this, eZ, (PMF)&FGAuxiliary::GetAeroPQR);
340 PropertyManager->Tie("velocities/phidot-rad_sec", this, ePhi, (PMF)&FGAuxiliary::GetEulerRates);
341 PropertyManager->Tie("velocities/thetadot-rad_sec", this, eTht, (PMF)&FGAuxiliary::GetEulerRates);
342 PropertyManager->Tie("velocities/psidot-rad_sec", this, ePsi, (PMF)&FGAuxiliary::GetEulerRates);
343 PropertyManager->Tie("velocities/u-aero-fps", this, eU, (PMF)&FGAuxiliary::GetAeroUVW);
344 PropertyManager->Tie("velocities/v-aero-fps", this, eV, (PMF)&FGAuxiliary::GetAeroUVW);
345 PropertyManager->Tie("velocities/w-aero-fps", this, eW, (PMF)&FGAuxiliary::GetAeroUVW);
346 PropertyManager->Tie("velocities/vt-fps", this, &FGAuxiliary::GetVt, &FGAuxiliary::SetVt, true);
347 PropertyManager->Tie("velocities/mach", this, &FGAuxiliary::GetMach, &FGAuxiliary::SetMach, true);
348 PropertyManager->Tie("velocities/vg-fps", this, &FGAuxiliary::GetVground);
349 PropertyManager->Tie("accelerations/a-pilot-x-ft_sec2", this, eX, (PMF)&FGAuxiliary::GetPilotAccel);
350 PropertyManager->Tie("accelerations/a-pilot-y-ft_sec2", this, eY, (PMF)&FGAuxiliary::GetPilotAccel);
351 PropertyManager->Tie("accelerations/a-pilot-z-ft_sec2", this, eZ, (PMF)&FGAuxiliary::GetPilotAccel);
352 PropertyManager->Tie("accelerations/n-pilot-x-norm", this, eX, (PMF)&FGAuxiliary::GetNpilot);
353 PropertyManager->Tie("accelerations/n-pilot-y-norm", this, eY, (PMF)&FGAuxiliary::GetNpilot);
354 PropertyManager->Tie("accelerations/n-pilot-z-norm", this, eZ, (PMF)&FGAuxiliary::GetNpilot);
355 PropertyManager->Tie("accelerations/Nz", this, &FGAuxiliary::GetNz);
356 /* PropertyManager->Tie("atmosphere/headwind-fps", this, &FGAuxiliary::GetHeadWind, true);
357 PropertyManager->Tie("atmosphere/crosswind-fps", this, &FGAuxiliary::GetCrossWind, true); */
358 PropertyManager->Tie("aero/alpha-rad", this, (PF)&FGAuxiliary::Getalpha, &FGAuxiliary::Setalpha, true);
359 PropertyManager->Tie("aero/beta-rad", this, (PF)&FGAuxiliary::Getbeta, &FGAuxiliary::Setbeta, true);
360 PropertyManager->Tie("aero/mag-beta-rad", this, (PF)&FGAuxiliary::GetMagBeta);
361 PropertyManager->Tie("aero/alpha-deg", this, inDegrees, (PMF)&FGAuxiliary::Getalpha);
362 PropertyManager->Tie("aero/beta-deg", this, inDegrees, (PMF)&FGAuxiliary::Getbeta);
363 PropertyManager->Tie("aero/mag-beta-deg", this, inDegrees, (PMF)&FGAuxiliary::GetMagBeta);
364 PropertyManager->Tie("aero/Re", this, &FGAuxiliary::GetReynoldsNumber);
365 PropertyManager->Tie("aero/qbar-psf", this, &FGAuxiliary::Getqbar, &FGAuxiliary::Setqbar, true);
366 PropertyManager->Tie("aero/qbarUW-psf", this, &FGAuxiliary::GetqbarUW, &FGAuxiliary::SetqbarUW, true);
367 PropertyManager->Tie("aero/qbarUV-psf", this, &FGAuxiliary::GetqbarUV, &FGAuxiliary::SetqbarUV, true);
368 PropertyManager->Tie("aero/alphadot-rad_sec", this, (PF)&FGAuxiliary::Getadot, &FGAuxiliary::Setadot, true);
369 PropertyManager->Tie("aero/betadot-rad_sec", this, (PF)&FGAuxiliary::Getbdot, &FGAuxiliary::Setbdot, true);
370 PropertyManager->Tie("aero/alphadot-deg_sec", this, inDegrees, (PMF)&FGAuxiliary::Getadot);
371 PropertyManager->Tie("aero/betadot-deg_sec", this, inDegrees, (PMF)&FGAuxiliary::Getbdot);
372 PropertyManager->Tie("aero/h_b-cg-ft", this, &FGAuxiliary::GetHOverBCG);
373 PropertyManager->Tie("aero/h_b-mac-ft", this, &FGAuxiliary::GetHOverBMAC);
374 PropertyManager->Tie("flight-path/gamma-rad", this, &FGAuxiliary::GetGamma, &FGAuxiliary::SetGamma);
375 PropertyManager->Tie("flight-path/psi-gt-rad", this, &FGAuxiliary::GetGroundTrack);
377 PropertyManager->Tie("position/distance-from-start-lon-mt", this, &FGAuxiliary::GetLongitudeRelativePosition);
378 PropertyManager->Tie("position/distance-from-start-lat-mt", this, &FGAuxiliary::GetLatitudeRelativePosition);
379 PropertyManager->Tie("position/distance-from-start-mag-mt", this, &FGAuxiliary::GetDistanceRelativePosition);
380 PropertyManager->Tie("position/vrp-gc-latitude_deg", &vLocationVRP, &FGLocation::GetLatitudeDeg);
381 PropertyManager->Tie("position/vrp-longitude_deg", &vLocationVRP, &FGLocation::GetLongitudeDeg);
382 PropertyManager->Tie("position/vrp-radius-ft", &vLocationVRP, &FGLocation::GetRadius);
385 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
387 void FGAuxiliary::CalculateRelativePosition(void)
389 const double earth_radius_mt = Inertial->GetRefRadius()*fttom;
390 lat_relative_position=(FDMExec->GetPropagate()->GetLatitude() - FDMExec->GetIC()->GetLatitudeDegIC() *degtorad)*earth_radius_mt;
391 lon_relative_position=(FDMExec->GetPropagate()->GetLongitude() - FDMExec->GetIC()->GetLongitudeDegIC()*degtorad)*earth_radius_mt;
392 relative_position = sqrt(lat_relative_position*lat_relative_position + lon_relative_position*lon_relative_position);
395 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
396 // The bitmasked value choices are as follows:
397 // unset: In this case (the default) JSBSim would only print
398 // out the normally expected messages, essentially echoing
399 // the config files as they are read. If the environment
400 // variable is not set, debug_lvl is set to 1 internally
401 // 0: This requests JSBSim not to output any messages
403 // 1: This value explicity requests the normal JSBSim
405 // 2: This value asks for a message to be printed out when
406 // a class is instantiated
407 // 4: When this value is set, a message is displayed when a
408 // FGModel object executes its Run() method
409 // 8: When this value is set, various runtime state variables
410 // are printed out periodically
411 // 16: When set various parameters are sanity checked and
412 // a message is printed out when they go out of bounds
414 void FGAuxiliary::Debug(int from)
416 if (debug_lvl <= 0) return;
418 if (debug_lvl & 1) { // Standard console startup message output
419 if (from == 0) { // Constructor
423 if (debug_lvl & 2 ) { // Instantiation/Destruction notification
424 if (from == 0) cout << "Instantiated: FGAuxiliary" << endl;
425 if (from == 1) cout << "Destroyed: FGAuxiliary" << endl;
427 if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
429 if (debug_lvl & 8 ) { // Runtime state variables
431 if (debug_lvl & 16) { // Sanity checking
432 if (Mach > 100 || Mach < 0.00)
433 cout << "FGPropagate::Mach is out of bounds: " << Mach << endl;
434 if (qbar > 1e6 || qbar < 0.00)
435 cout << "FGPropagate::qbar is out of bounds: " << qbar << endl;
437 if (debug_lvl & 64) {
438 if (from == 0) { // Constructor
439 cout << IdSrc << endl;
440 cout << IdHdr << endl;
445 } // namespace JSBSim