1 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
3 Module: FGTranslation.cpp
6 Purpose: Integrates the translational EOM
9 ------------- Copyright (C) 1999 Jon S. Berndt (jsb@hal-pc.org) -------------
11 This program is free software; you can redistribute it and/or modify it under
12 the terms of the GNU 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 General Public License for more
21 You should have received a copy of the GNU 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 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 integrates the translational EOM.
33 --------------------------------------------------------------------------------
35 7/23/99 TP Added data member and modified Run and PutState to calcuate
38 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
39 COMMENTS, REFERENCES, and NOTES
40 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
41 [1] Cooke, Zyda, Pratt, and McGhee, "NPSNET: Flight Simulation Dynamic Modeling
42 Using Quaternions", Presence, Vol. 1, No. 4, pp. 404-420 Naval Postgraduate
44 [2] D. M. Henderson, "Euler Angles, Quaternions, and Transformation Matrices",
46 [3] Richard E. McFarland, "A Standard Kinematic Model for Flight Simulation at
47 NASA-Ames", NASA CR-2497, January 1975
48 [4] Barnes W. McCormick, "Aerodynamics, Aeronautics, and Flight Mechanics",
49 Wiley & Sons, 1979 ISBN 0-471-03032-5
50 [5] Bernard Etkin, "Dynamics of Flight, Stability and Control", Wiley & Sons,
51 1982 ISBN 0-471-08936-2
53 The order of rotations used in this class corresponds to a 3-2-1 sequence,
54 or Y-P-R, or Z-Y-X, if you prefer.
56 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
58 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
60 #include "FGTranslation.h"
61 #include "FGRotation.h"
62 #include "FGAtmosphere.h"
64 #include "FGFDMExec.h"
66 #include "FGMassBalance.h"
67 #include "FGAircraft.h"
68 #include "FGPosition.h"
69 #include "FGAuxiliary.h"
71 #include "FGPropertyManager.h"
73 static const char *IdSrc = "$Id$";
74 static const char *IdHdr = ID_TRANSLATION;
76 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
78 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
81 FGTranslation::FGTranslation(FGFDMExec* fdmex) : FGModel(fdmex)
83 Name = "FGTranslation";
93 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
95 FGTranslation::~FGTranslation(void)
101 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
103 bool FGTranslation::Run(void)
105 double Tc = 0.5*State->Getdt()*rate;
107 if (!FGModel::Run()) {
110 mVel(1,2) = -vUVW(eW);
111 mVel(1,3) = vUVW(eV);
112 mVel(2,1) = vUVW(eW);
114 mVel(2,3) = -vUVW(eU);
115 mVel(3,1) = -vUVW(eV);
116 mVel(3,2) = vUVW(eU);
119 vUVWdot = mVel*Rotation->GetPQR() + Aircraft->GetBodyAccel();
121 vUVW += Tc*(vUVWdot + vlastUVWdot);
123 vAeroUVW = vUVW + State->GetTl2b()*Atmosphere->GetWindNED();
125 Vt = vAeroUVW.Magnitude();
127 if (vAeroUVW(eW) != 0.0)
128 alpha = vAeroUVW(eU)*vAeroUVW(eU) > 0.0 ? atan2(vAeroUVW(eW), vAeroUVW(eU)) : 0.0;
129 if (vAeroUVW(eV) != 0.0)
130 beta = vAeroUVW(eU)*vAeroUVW(eU)+vAeroUVW(eW)*vAeroUVW(eW) > 0.0 ? atan2(vAeroUVW(eV),
131 sqrt(vAeroUVW(eU)*vAeroUVW(eU) + vAeroUVW(eW)*vAeroUVW(eW))) : 0.0;
133 // stolen, quite shamelessly, from LaRCsim
134 double mUW = (vAeroUVW(eU)*vAeroUVW(eU) + vAeroUVW(eW)*vAeroUVW(eW));
136 if (vAeroUVW(eU) != 0.0)
137 signU = vAeroUVW(eU)/fabs(vAeroUVW(eU));
139 if ( (mUW == 0.0) || (Vt == 0.0) ) {
143 adot = (vAeroUVW(eU)*vAeroUVW(eW) - vAeroUVW(eW)*vUVWdot(eU))/mUW;
144 bdot = (signU*mUW*vUVWdot(eV) - vAeroUVW(eV)*(vAeroUVW(eU)*vUVWdot(eU)
145 + vAeroUVW(eW)*vUVWdot(eW)))/(Vt*Vt*sqrt(mUW));
148 alpha = beta = adot = bdot = 0;
151 qbar = 0.5*Atmosphere->GetDensity()*Vt*Vt;
152 Mach = Vt / State->Geta();
154 vlastUVWdot = vUVWdot;
156 if (debug_lvl > 1) Debug(1);
164 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
165 // The bitmasked value choices are as follows:
166 // unset: In this case (the default) JSBSim would only print
167 // out the normally expected messages, essentially echoing
168 // the config files as they are read. If the environment
169 // variable is not set, debug_lvl is set to 1 internally
170 // 0: This requests JSBSim not to output any messages
172 // 1: This value explicity requests the normal JSBSim
174 // 2: This value asks for a message to be printed out when
175 // a class is instantiated
176 // 4: When this value is set, a message is displayed when a
177 // FGModel object executes its Run() method
178 // 8: When this value is set, various runtime state variables
179 // are printed out periodically
180 // 16: When set various parameters are sanity checked and
181 // a message is printed out when they go out of bounds
183 void FGTranslation::Debug(int from)
185 if (debug_lvl <= 0) return;
187 if (debug_lvl & 1) { // Standard console startup message output
188 if (from == 0) { // Constructor
192 if (debug_lvl & 2 ) { // Instantiation/Destruction notification
193 if (from == 0) cout << "Instantiated: FGTranslation" << endl;
194 if (from == 1) cout << "Destroyed: FGTranslation" << endl;
196 if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
198 if (debug_lvl & 8 ) { // Runtime state variables
200 if (debug_lvl & 16) { // Sanity checking
201 if (fabs(vUVW(eU)) > 1e6)
202 cout << "FGTranslation::U velocity out of bounds: " << vUVW(eU) << endl;
203 if (fabs(vUVW(eV)) > 1e6)
204 cout << "FGTranslation::V velocity out of bounds: " << vUVW(eV) << endl;
205 if (fabs(vUVW(eW)) > 1e6)
206 cout << "FGTranslation::W velocity out of bounds: " << vUVW(eW) << endl;
207 if (fabs(vUVWdot(eU)) > 1e4)
208 cout << "FGTranslation::U acceleration out of bounds: " << vUVWdot(eU) << endl;
209 if (fabs(vUVWdot(eV)) > 1e4)
210 cout << "FGTranslation::V acceleration out of bounds: " << vUVWdot(eV) << endl;
211 if (fabs(vUVWdot(eW)) > 1e4)
212 cout << "FGTranslation::W acceleration out of bounds: " << vUVWdot(eW) << endl;
213 if (Mach > 100 || Mach < 0.00)
214 cout << "FGTranslation::Mach is out of bounds: " << Mach << endl;
215 if (qbar > 1e6 || qbar < 0.00)
216 cout << "FGTranslation::qbar is out of bounds: " << qbar << endl;
218 if (debug_lvl & 64) {
219 if (from == 0) { // Constructor
220 cout << IdSrc << endl;
221 cout << IdHdr << endl;
226 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
228 void FGTranslation::bind(void){
229 PropertyManager->Tie("velocities/u-fps", this,1,
230 &FGTranslation::GetUVW /*,
231 &FGTranslation::SetUVW,
233 PropertyManager->Tie("velocities/v-fps", this,2,
234 &FGTranslation::GetUVW /*,
235 &FGTranslation::SetUVW,
237 PropertyManager->Tie("velocities/w-fps", this,3,
238 &FGTranslation::GetUVW /*,
239 &FGTranslation::SetUVW,
241 PropertyManager->Tie("accelerations/udot-fps", this,1,
242 &FGTranslation::GetUVWdot);
243 PropertyManager->Tie("accelerations/vdot-fps", this,2,
244 &FGTranslation::GetUVWdot);
245 PropertyManager->Tie("accelerations/wdot-fps", this,3,
246 &FGTranslation::GetUVWdot);
247 PropertyManager->Tie("velocities/u-aero-fps", this,1,
248 &FGTranslation::GetAeroUVW);
249 PropertyManager->Tie("velocities/v-aero-fps", this,2,
250 &FGTranslation::GetAeroUVW);
251 PropertyManager->Tie("velocities/w-aero-fps", this,3,
252 &FGTranslation::GetAeroUVW);
253 PropertyManager->Tie("aero/alpha-rad", this,
254 &FGTranslation::Getalpha,
255 &FGTranslation::Setalpha,
257 PropertyManager->Tie("aero/beta-rad", this,
258 &FGTranslation::Getbeta,
259 &FGTranslation::Setbeta,
261 PropertyManager->Tie("aero/mag-beta-rad", this,
262 &FGTranslation::GetMagBeta);
263 PropertyManager->Tie("aero/qbar-psf", this,
264 &FGTranslation::Getqbar,
265 &FGTranslation::Setqbar,
267 PropertyManager->Tie("velocities/vt-fps", this,
268 &FGTranslation::GetVt,
269 &FGTranslation::SetVt,
271 PropertyManager->Tie("velocities/mach-norm", this,
272 &FGTranslation::GetMach,
273 &FGTranslation::SetMach,
275 PropertyManager->Tie("aero/alphadot-rad_sec", this,
276 &FGTranslation::Getadot,
277 &FGTranslation::Setadot,
279 PropertyManager->Tie("aero/betadot-rad_sec", this,
280 &FGTranslation::Getbdot,
281 &FGTranslation::Setbdot,
285 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
287 void FGTranslation::unbind(void){
288 PropertyManager->Untie("velocities/u-fps");
289 PropertyManager->Untie("velocities/v-fps");
290 PropertyManager->Untie("velocities/w-fps");
291 PropertyManager->Untie("accelerations/udot-fps");
292 PropertyManager->Untie("accelerations/vdot-fps");
293 PropertyManager->Untie("accelerations/wdot-fps");
294 PropertyManager->Untie("velocities/u-aero-fps");
295 PropertyManager->Untie("velocities/v-aero-fps");
296 PropertyManager->Untie("velocities/w-aero-fps");
297 PropertyManager->Untie("aero/alpha-rad");
298 PropertyManager->Untie("aero/beta-rad");
299 PropertyManager->Untie("aero/qbar-psf");
300 PropertyManager->Untie("velocities/vt-fps");
301 PropertyManager->Untie("velocities/mach-norm");
302 PropertyManager->Untie("aero/alphadot-rad_sec");
303 PropertyManager->Untie("aero/betadot-rad_sec");