1 // JSBsim.cxx -- interface to the JSBsim flight model
3 // Written by Curtis Olson, started February 1999.
5 // Copyright (C) 1999 Curtis L. Olson - curt@flightgear.org
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 #include <simgear/compiler.h>
26 #ifdef FG_MATH_EXCEPTION_CLASH
32 #include <simgear/constants.h>
33 #include <simgear/debug/logstream.hxx>
34 #include <simgear/math/sg_geodesy.hxx>
35 #include <simgear/misc/fgpath.hxx>
37 #include <Scenery/scenery.hxx>
39 #include <Aircraft/aircraft.hxx>
40 #include <Controls/controls.hxx>
41 #include <Main/options.hxx>
43 #include <FDM/JSBSim/FGFDMExec.h>
44 #include <FDM/JSBSim/FGAircraft.h>
45 #include <FDM/JSBSim/FGFCS.h>
46 #include <FDM/JSBSim/FGPosition.h>
47 #include <FDM/JSBSim/FGRotation.h>
48 #include <FDM/JSBSim/FGState.h>
49 #include <FDM/JSBSim/FGTranslation.h>
50 #include <FDM/JSBSim/FGAuxiliary.h>
51 #include <FDM/JSBSim/FGDefs.h>
52 #include <FDM/JSBSim/FGInitialCondition.h>
53 #include <FDM/JSBSim/FGTrim.h>
54 #include <FDM/JSBSim/FGAtmosphere.h>
58 /******************************************************************************/
60 // Initialize the JSBsim flight model, dt is the time increment for
61 // each subsequent iteration through the EOM
63 bool FGJSBsim::init( double dt ) {
67 FG_LOG( FG_FLIGHT, FG_INFO, "Starting and initializing JSBsim" );
68 FG_LOG( FG_FLIGHT, FG_INFO, " created FDMExec" );
70 FGPath aircraft_path( globals->get_options()->get_fg_root() );
71 aircraft_path.append( "Aircraft" );
73 FGPath engine_path( globals->get_options()->get_fg_root() );
74 engine_path.append( "Engine" );
76 //FDMExec.GetState()->Setdt( dt );
78 result = FDMExec.LoadModel( aircraft_path.str(),
80 globals->get_options()->get_aircraft() );
81 FDMExec.GetState()->Setdt( dt );
84 FG_LOG( FG_FLIGHT, FG_INFO, " loaded aircraft "
85 << globals->get_options()->get_aircraft() );
87 FG_LOG( FG_FLIGHT, FG_INFO, " aircraft "
88 << globals->get_options()->get_aircraft()
89 << " does not exist" );
93 FDMExec.GetAtmosphere()->SetExTemperature(get_Static_temperature());
94 FDMExec.GetAtmosphere()->SetExPressure(get_Static_pressure());
95 FDMExec.GetAtmosphere()->SetExDensity(get_Density());
96 FDMExec.GetAtmosphere()->SetWindNED(get_V_north_airmass(),
98 get_V_down_airmass());
100 FDMExec.GetAtmosphere()->UseInternal();
103 FDMExec.GetPosition()->SetRunwayRadius(scenery.cur_radius*METER_TO_FEET);
104 FDMExec.GetPosition()->SetSeaLevelRadius(get_Sea_level_radius());
106 FG_LOG( FG_FLIGHT, FG_INFO, " Initializing JSBSim with:" );
108 FGInitialCondition *fgic = new FGInitialCondition(&FDMExec);
109 fgic->SetAltitudeFtIC(get_Altitude());
110 if ( (globals->get_options()->get_mach() < 0) &&
111 (globals->get_options()->get_vc() < 0 ) )
113 fgic->SetUBodyFpsIC(globals->get_options()->get_uBody());
114 fgic->SetVBodyFpsIC(globals->get_options()->get_vBody());
115 fgic->SetWBodyFpsIC(globals->get_options()->get_wBody());
116 FG_LOG(FG_FLIGHT,FG_INFO, " u,v,w= " << globals->get_options()->get_uBody()
117 << ", " << globals->get_options()->get_vBody()
118 << ", " << globals->get_options()->get_wBody());
119 } else if (globals->get_options()->get_vc() < 0) {
120 fgic->SetMachIC(globals->get_options()->get_mach());
121 FG_LOG( FG_FLIGHT,FG_INFO, " mach: "
122 << globals->get_options()->get_mach() );
124 fgic->SetVcalibratedKtsIC(globals->get_options()->get_vc());
125 FG_LOG(FG_FLIGHT,FG_INFO, " vc: " << globals->get_options()->get_vc() );
126 //this should cover the case in which no speed switches are used
127 //globals->get_options()->get_vc() will return zero by default
130 //fgic->SetFlightPathAngleDegIC(globals->get_options()->get_Gamma());
131 fgic->SetRollAngleRadIC(get_Phi());
132 fgic->SetPitchAngleRadIC(get_Theta());
133 fgic->SetHeadingRadIC(get_Psi());
134 fgic->SetLatitudeRadIC(get_Lat_geocentric());
135 fgic->SetLongitudeRadIC(get_Longitude());
137 // FG_LOG( FG_FLIGHT, FG_INFO, " gamma: "
138 // << globals->get_options()->get_Gamma());
139 FG_LOG( FG_FLIGHT, FG_INFO, " phi: " << get_Phi());
140 //FG_LOG( FG_FLIGHT, FG_INFO, " theta: " << get_Theta() );
141 FG_LOG( FG_FLIGHT, FG_INFO, " psi: " << get_Psi() );
142 FG_LOG( FG_FLIGHT, FG_INFO, " lat: " << get_Latitude() );
143 FG_LOG( FG_FLIGHT, FG_INFO, " lon: " << get_Longitude() );
145 FG_LOG( FG_FLIGHT, FG_INFO, " Pressure Altiude: " << get_Altitude() );
146 FG_LOG( FG_FLIGHT, FG_INFO, " Terrain Altitude: "
147 << scenery.cur_radius*METER_TO_FEET );
148 FG_LOG( FG_FLIGHT, FG_INFO, " AGL Altitude: "
149 << get_Altitude() + get_Sea_level_radius()
150 - scenery.cur_radius*METER_TO_FEET );
152 FG_LOG( FG_FLIGHT, FG_INFO, " globals->get_options()->get_altitude(): "
153 << globals->get_options()->get_altitude() );
154 //must check > 0, != 0 will give bad result if --notrim set
155 if(globals->get_options()->get_trim_mode() > 0) {
156 if(fgic->GetVcalibratedKtsIC() > 50) {
158 FG_LOG( FG_FLIGHT, FG_INFO, " Starting trim..." );
159 FGTrim *fgtrim=new FGTrim(&FDMExec,fgic,tLongitudinal);
163 fgtrim->ReportState();
166 controls.set_elevator_trim(FDMExec.GetFCS()->GetPitchTrimCmd());
167 controls.set_throttle( FGControls::ALL_ENGINES,
168 FDMExec.GetFCS()->GetThrottleCmd(0)/100 );
170 trim_elev=FDMExec.GetFCS()->GetPitchTrimCmd();
171 trim_throttle=FDMExec.GetFCS()->GetThrottleCmd(0)/100;
172 //the trimming routine only knows how to get 1 value for throttle
176 FG_LOG( FG_FLIGHT, FG_INFO, " Trim complete." );
178 FG_LOG( FG_FLIGHT, FG_INFO, " Initializing without trim" );
179 FDMExec.GetState()->Initialize(fgic);
185 FG_LOG( FG_FLIGHT, FG_INFO, " loaded initial conditions" );
187 FG_LOG( FG_FLIGHT, FG_INFO, " set dt" );
189 FG_LOG( FG_FLIGHT, FG_INFO, "Finished initializing JSBSim" );
196 /******************************************************************************/
198 // Run an iteration of the EOM (equations of motion)
200 bool FGJSBsim::update( int multiloop ) {
201 double save_alt = 0.0;
202 double time_step = (1.0 / globals->get_options()->get_model_hz()) * multiloop;
203 double start_elev = get_Altitude();
206 // lets try to avoid really screwing up the JSBsim model
207 if ( get_Altitude() < -9000 ) {
208 save_alt = get_Altitude();
214 controls.set_elevator_trim(trim_elev);
215 controls.set_throttle(FGControls::ALL_ENGINES,trim_throttle);
217 controls.set_elevator(0.0);
218 controls.set_aileron(0.0);
219 controls.set_rudder(0.0);
226 for ( int i = 0; i < multiloop; i++ ) {
230 // printf("%d FG_Altitude = %.2f\n", i, FG_Altitude * 0.3048);
231 // printf("%d Altitude = %.2f\n", i, Altitude * 0.3048);
233 // translate JSBsim back to FG structure so that the
234 // autopilot (and the rest of the sim can use the updated values
238 // but lets restore our original bogus altitude when we are done
240 if ( save_alt < -9000.0 ) {
241 set_Altitude( save_alt );
244 double end_elev = get_Altitude();
249 /******************************************************************************/
251 // Convert from the FGInterface struct to the JSBsim generic_ struct
253 bool FGJSBsim::copy_to_JSBsim() {
254 // copy control positions into the JSBsim structure
256 FDMExec.GetFCS()->SetDaCmd( controls.get_aileron());
257 FDMExec.GetFCS()->SetDeCmd( controls.get_elevator());
258 FDMExec.GetFCS()->SetPitchTrimCmd(controls.get_elevator_trim());
259 FDMExec.GetFCS()->SetDrCmd( -1*controls.get_rudder());
260 FDMExec.GetFCS()->SetDfCmd( controls.get_flaps() );
261 FDMExec.GetFCS()->SetDsbCmd( 0.0 ); //speedbrakes
262 FDMExec.GetFCS()->SetDspCmd( 0.0 ); //spoilers
263 FDMExec.GetFCS()->SetThrottleCmd( FGControls::ALL_ENGINES,
264 controls.get_throttle( 0 ) * 100.0 );
266 FDMExec.GetFCS()->SetLBrake( controls.get_brake( 0 ) );
267 FDMExec.GetFCS()->SetRBrake( controls.get_brake( 1 ) );
268 FDMExec.GetFCS()->SetCBrake( controls.get_brake( 2 ) );
270 // Inform JSBsim of the local terrain altitude; uncommented 5/3/00
271 // FDMExec.GetPosition()->SetRunwayElevation(get_Runway_altitude()); // seems to work
272 FDMExec.GetPosition()->SetRunwayRadius(scenery.cur_radius*METER_TO_FEET);
273 FDMExec.GetPosition()->SetSeaLevelRadius(get_Sea_level_radius());
275 FDMExec.GetAtmosphere()->SetExTemperature(get_Static_temperature());
276 FDMExec.GetAtmosphere()->SetExPressure(get_Static_pressure());
277 FDMExec.GetAtmosphere()->SetExDensity(get_Density());
278 FDMExec.GetAtmosphere()->SetWindNED(get_V_north_airmass(),
279 get_V_east_airmass(),
280 get_V_down_airmass());
285 /******************************************************************************/
287 // Convert from the JSBsim generic_ struct to the FGInterface struct
289 bool FGJSBsim::copy_from_JSBsim() {
291 set_Inertias( FDMExec.GetAircraft()->GetMass(),
292 FDMExec.GetAircraft()->GetIxx(),
293 FDMExec.GetAircraft()->GetIyy(),
294 FDMExec.GetAircraft()->GetIzz(),
295 FDMExec.GetAircraft()->GetIxz() );
297 set_CG_Position ( FDMExec.GetAircraft()->GetXYZcg()(1),
298 FDMExec.GetAircraft()->GetXYZcg()(2),
299 FDMExec.GetAircraft()->GetXYZcg()(3) );
301 set_Accels_Body ( FDMExec.GetTranslation()->GetUVWdot()(1),
302 FDMExec.GetTranslation()->GetUVWdot()(2),
303 FDMExec.GetTranslation()->GetUVWdot()(3) );
305 set_Accels_CG_Body ( FDMExec.GetTranslation()->GetUVWdot()(1),
306 FDMExec.GetTranslation()->GetUVWdot()(2),
307 FDMExec.GetTranslation()->GetUVWdot()(3) );
309 //set_Accels_CG_Body_N ( FDMExec.GetTranslation()->GetNcg()(1),
310 // FDMExec.GetTranslation()->GetNcg()(2),
311 // FDMExec.GetTranslation()->GetNcg()(3) );
313 set_Accels_Pilot_Body( FDMExec.GetAuxiliary()->GetPilotAccel()(1),
314 FDMExec.GetAuxiliary()->GetPilotAccel()(2),
315 FDMExec.GetAuxiliary()->GetPilotAccel()(3) );
317 //set_Accels_Pilot_Body_N( FDMExec.GetAuxiliary()->GetNpilot()(1),
318 // FDMExec.GetAuxiliary()->GetNpilot()(2),
319 // FDMExec.GetAuxiliary()->GetNpilot()(3) );
323 set_Nlf( FDMExec.GetAircraft()->GetNlf());
329 set_Velocities_Local( FDMExec.GetPosition()->GetVn(),
330 FDMExec.GetPosition()->GetVe(),
331 FDMExec.GetPosition()->GetVd() );
333 set_Velocities_Wind_Body( FDMExec.GetTranslation()->GetUVW()(1),
334 FDMExec.GetTranslation()->GetUVW()(2),
335 FDMExec.GetTranslation()->GetUVW()(3) );
337 set_V_equiv_kts( FDMExec.GetAuxiliary()->GetVequivalentKTS() );
339 //set_V_calibrated( FDMExec.GetAuxiliary()->GetVcalibratedFPS() );
341 set_V_calibrated_kts( FDMExec.GetAuxiliary()->GetVcalibratedKTS() );
343 set_V_ground_speed ( FDMExec.GetPosition()->GetVground() );
345 set_Omega_Body( FDMExec.GetState()->GetParameter(FG_ROLLRATE),
346 FDMExec.GetState()->GetParameter(FG_PITCHRATE),
347 FDMExec.GetState()->GetParameter(FG_YAWRATE) );
349 set_Euler_Rates( FDMExec.GetRotation()->GetEulerRates()(2),
350 FDMExec.GetRotation()->GetEulerRates()(1),
351 FDMExec.GetRotation()->GetEulerRates()(3));
353 // ***FIXME*** set_Geocentric_Rates( Latitude_dot, Longitude_dot,
356 set_Mach_number( FDMExec.GetTranslation()->GetMach());
360 double lat_geoc = FDMExec.GetPosition()->GetLatitude();
361 double lon = FDMExec.GetPosition()->GetLongitude();
362 double alt = FDMExec.GetPosition()->Geth();
363 double lat_geod, tmp_alt, sl_radius1, sl_radius2, tmp_lat_geoc;
365 sgGeocToGeod( lat_geoc, EQUATORIAL_RADIUS_M + alt * FEET_TO_METER,
366 &lat_geod, &tmp_alt, &sl_radius1 );
367 sgGeodToGeoc( lat_geod, alt * FEET_TO_METER, &sl_radius2, &tmp_lat_geoc );
369 FG_LOG( FG_FLIGHT, FG_DEBUG, "lon = " << lon << " lat_geod = " << lat_geod
370 << " lat_geoc = " << lat_geoc
371 << " alt = " << alt << " tmp_alt = " << tmp_alt * METER_TO_FEET
372 << " sl_radius1 = " << sl_radius1 * METER_TO_FEET
373 << " sl_radius2 = " << sl_radius2 * METER_TO_FEET
374 << " Equator = " << EQUATORIAL_RADIUS_FT );
376 set_Geocentric_Position( lat_geoc, lon,
377 sl_radius2 * METER_TO_FEET + alt );
378 set_Geodetic_Position( lat_geod, lon, alt );
379 set_Euler_Angles( FDMExec.GetRotation()->Getphi(),
380 FDMExec.GetRotation()->Gettht(),
381 FDMExec.GetRotation()->Getpsi() );
383 set_Alpha( FDMExec.GetTranslation()->Getalpha() );
384 set_Beta( FDMExec.GetTranslation()->Getbeta() );
386 set_Gamma_vert_rad( FDMExec.GetPosition()->GetGamma() );
387 // set_Gamma_horiz_rad( Gamma_horiz_rad );
389 /* **FIXME*** */ set_Sea_level_radius( sl_radius2 * METER_TO_FEET );
390 /* **FIXME*** */ set_Earth_position_angle( 0.0 );
392 // /* ***FIXME*** */ set_Runway_altitude( 0.0 );
394 set_sin_lat_geocentric( lat_geoc );
395 set_cos_lat_geocentric( lat_geoc );
396 set_sin_cos_longitude( lon );
397 set_sin_cos_latitude( lat_geod );
399 set_Climb_Rate(FDMExec.GetPosition()->Gethdot());