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/fg_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/FGTrimLong.h>
54 #include <FDM/JSBsim/FGAtmosphere.h>
60 /******************************************************************************/
62 // Initialize the JSBsim flight model, dt is the time increment for
63 // each subsequent iteration through the EOM
65 int FGJSBsim::init( double dt ) {
69 FG_LOG( FG_FLIGHT, FG_INFO, "Starting and initializing JSBsim" );
70 FG_LOG( FG_FLIGHT, FG_INFO, " created FDMExec" );
72 FGPath aircraft_path( current_options.get_fg_root() );
73 aircraft_path.append( "Aircraft" );
75 FGPath engine_path( current_options.get_fg_root() );
76 engine_path.append( "Engine" );
78 FDMExec.GetState()->Setdt( dt );
80 FDMExec.GetAircraft()->LoadAircraft( aircraft_path.str(),
82 current_options.get_aircraft() );
84 FG_LOG( FG_FLIGHT, FG_INFO, " loaded aircraft" <<
85 current_options.get_aircraft() );
87 FDMExec.GetAtmosphere()->UseInternal();
89 FG_LOG( FG_FLIGHT, FG_INFO, " Initializing JSBsim with:" );
91 FGInitialCondition *fgic = new FGInitialCondition(&FDMExec);
92 fgic->SetAltitudeFtIC(get_Altitude());
93 if((current_options.get_mach() < 0) && (current_options.get_vc() < 0 )) {
94 fgic->SetUBodyFpsIC(current_options.get_uBody());
95 fgic->SetVBodyFpsIC(current_options.get_vBody());
96 fgic->SetWBodyFpsIC(current_options.get_wBody());
97 FG_LOG(FG_FLIGHT,FG_INFO, " u,v,w= " << current_options.get_uBody()
98 << ", " << current_options.get_vBody()
99 << ", " << current_options.get_wBody());
100 } else if (current_options.get_vc() < 0) {
101 fgic->SetMachIC(current_options.get_mach());
102 FG_LOG(FG_FLIGHT,FG_INFO, " mach: " << current_options.get_mach() );
104 fgic->SetVcalibratedKtsIC(current_options.get_vc());
105 FG_LOG(FG_FLIGHT,FG_INFO, " vc: " << current_options.get_vc() );
106 //this should cover the case in which no speed switches are used
107 //current_options.get_vc() will return zero by default
111 fgic->SetRollAngleRadIC(get_Phi());
112 fgic->SetPitchAngleRadIC(get_Theta());
113 fgic->SetHeadingRadIC(get_Psi());
114 fgic->SetLatitudeRadIC(get_Latitude());
115 fgic->SetLongitudeRadIC(get_Longitude());
117 FDMExec.GetPosition()->SetRunwayRadius(geocRwyRadius);
119 FG_LOG( FG_FLIGHT, FG_INFO, " phi: " << get_Phi());
120 FG_LOG( FG_FLIGHT, FG_INFO, " theta: " << get_Theta() );
121 FG_LOG( FG_FLIGHT, FG_INFO, " psi: " << get_Psi() );
122 FG_LOG( FG_FLIGHT, FG_INFO, " lat: " << get_Latitude() );
123 FG_LOG( FG_FLIGHT, FG_INFO, " lon: " << get_Longitude() );
124 FG_LOG( FG_FLIGHT, FG_INFO, " alt: " << get_Altitude() );
126 if(current_options.get_trim_mode() == true) {
127 FG_LOG( FG_FLIGHT, FG_INFO, " Starting trim..." );
128 FGTrimLong *fgtrim=new FGTrimLong(&FDMExec,fgic);
132 fgtrim->ReportState();
134 controls.set_elevator_trim(FDMExec.GetFCS()->GetDeCmd());
135 controls.set_trimmed_throttle(FGControls::ALL_ENGINES,FDMExec.GetFCS()->GetThrottleCmd(0)/100);
136 //the trimming routine only knows how to get 1 value for throttle
138 //for(int i=0;i<FDMExec.GetAircraft()->GetNumEngines();i++) {
139 // controls.set_throttle(i,FDMExec.GetFCS()->GetThrottleCmd(i)/100);
142 FG_LOG( FG_FLIGHT, FG_INFO, " Trim complete." );
144 FG_LOG( FG_FLIGHT, FG_INFO, " Initializing without trim" );
145 FDMExec.GetState()->Initialize(fgic);
151 FG_LOG( FG_FLIGHT, FG_INFO, " loaded initial conditions" );
153 FG_LOG( FG_FLIGHT, FG_INFO, " set dt" );
155 FG_LOG( FG_FLIGHT, FG_INFO, "Finished initializing JSBsim" );
162 /******************************************************************************/
164 // Run an iteration of the EOM (equations of motion)
166 int FGJSBsim::update( int multiloop ) {
167 double save_alt = 0.0;
168 double time_step = (1.0 / current_options.get_model_hz()) * multiloop;
169 double start_elev = get_Altitude();
171 // lets try to avoid really screwing up the JSBsim model
172 if ( get_Altitude() < -9000 ) {
173 save_alt = get_Altitude();
177 // copy control positions into the JSBsim structure
179 FDMExec.GetFCS()->SetDaCmd( controls.get_aileron());
180 FDMExec.GetFCS()->SetDeCmd( controls.get_elevator());
181 FDMExec.GetFCS()->SetPitchTrimCmd(controls.get_elevator_trim());
182 FDMExec.GetFCS()->SetDrCmd( controls.get_rudder());
183 FDMExec.GetFCS()->SetDfCmd( controls.get_flaps() );
184 FDMExec.GetFCS()->SetDsbCmd( 0.0 );
185 FDMExec.GetFCS()->SetDspCmd( 0.0 );
186 FDMExec.GetFCS()->SetThrottleCmd( FGControls::ALL_ENGINES,
187 controls.get_throttle( 0 ) * 100.0 );
189 // FCS->SetBrake( controls.get_brake( 0 ) );
191 // Inform JSBsim of the local terrain altitude; uncommented 5/3/00
192 // FDMExec.GetPosition()->SetRunwayElevation(get_Runway_altitude()); // seems to work
193 FDMExec.GetPosition()->SetRunwayRadius(geocRwyRadius);
195 FDMExec.GetAtmosphere()->SetExTemperature(get_Static_temperature());
196 FDMExec.GetAtmosphere()->SetExPressure(get_Static_pressure());
197 FDMExec.GetAtmosphere()->SetExDensity(get_Density());
198 FDMExec.GetAtmosphere()->SetWindNED(get_V_north_airmass(),
199 get_V_east_airmass(),
200 get_V_down_airmass());
202 for ( int i = 0; i < multiloop; i++ ) {
206 // printf("%d FG_Altitude = %.2f\n", i, FG_Altitude * 0.3048);
207 // printf("%d Altitude = %.2f\n", i, Altitude * 0.3048);
209 // translate JSBsim back to FG structure so that the
210 // autopilot (and the rest of the sim can use the updated values
214 // but lets restore our original bogus altitude when we are done
216 if ( save_alt < -9000.0 ) {
217 set_Altitude( save_alt );
220 double end_elev = get_Altitude();
221 if ( time_step > 0.0 ) {
223 set_Climb_Rate( (end_elev - start_elev) / time_step );
229 /******************************************************************************/
231 // Convert from the FGInterface struct to the JSBsim generic_ struct
233 int FGJSBsim::copy_to_JSBsim() {
237 /******************************************************************************/
239 // Convert from the JSBsim generic_ struct to the FGInterface struct
241 int FGJSBsim::copy_from_JSBsim() {
245 set_Velocities_Local( FDMExec.GetPosition()->GetVn(),
246 FDMExec.GetPosition()->GetVe(),
247 FDMExec.GetPosition()->GetVd() );
249 set_V_equiv_kts( FDMExec.GetAuxiliary()->GetVequivalentKTS() );
251 //set_V_calibrated( FDMExec.GetAuxiliary()->GetVcalibratedFPS() );
253 set_V_calibrated_kts( FDMExec.GetAuxiliary()->GetVcalibratedKTS() );
255 set_Omega_Body( FDMExec.GetState()->GetParameter(FG_ROLLRATE),
256 FDMExec.GetState()->GetParameter(FG_PITCHRATE),
257 FDMExec.GetState()->GetParameter(FG_YAWRATE) );
259 set_Euler_Rates( FDMExec.GetRotation()->Getphi(),
260 FDMExec.GetRotation()->Gettht(),
261 FDMExec.GetRotation()->Getpsi() );
263 // ***FIXME*** set_Geocentric_Rates( Latitude_dot, Longitude_dot, Radius_dot );
265 set_Mach_number( FDMExec.GetTranslation()->GetMach());
269 double lat_geoc = FDMExec.GetPosition()->GetLatitude();
270 double lon = FDMExec.GetPosition()->GetLongitude();
271 double alt = FDMExec.GetPosition()->Geth();
272 double lat_geod, tmp_alt, sl_radius1, sl_radius2, tmp_lat_geoc;
274 fgGeocToGeod( lat_geoc, EQUATORIAL_RADIUS_M + alt * FEET_TO_METER,
275 &lat_geod, &tmp_alt, &sl_radius1 );
276 fgGeodToGeoc( lat_geod, alt * FEET_TO_METER, &sl_radius2, &tmp_lat_geoc );
278 FG_LOG( FG_FLIGHT, FG_DEBUG, "lon = " << lon << " lat_geod = " << lat_geod
279 << " lat_geoc = " << lat_geoc
280 << " alt = " << alt << " tmp_alt = " << tmp_alt * METER_TO_FEET
281 << " sl_radius1 = " << sl_radius1 * METER_TO_FEET
282 << " sl_radius2 = " << sl_radius2 * METER_TO_FEET
283 << " Equator = " << EQUATORIAL_RADIUS_FT );
285 set_Geocentric_Position( lat_geoc, lon,
286 sl_radius2 * METER_TO_FEET + alt );
287 set_Geodetic_Position( lat_geod, lon, alt );
288 set_Euler_Angles( FDMExec.GetRotation()->Getphi(),
289 FDMExec.GetRotation()->Gettht(),
290 FDMExec.GetRotation()->Getpsi() );
292 set_Alpha( FDMExec.GetTranslation()->Getalpha() );
293 set_Beta( FDMExec.GetTranslation()->Getbeta() );
295 set_Gamma_vert_rad( FDMExec.GetPosition()->GetGamma() );
296 // set_Gamma_horiz_rad( Gamma_horiz_rad );
298 /* **FIXME*** */ set_Sea_level_radius( sl_radius2 * METER_TO_FEET );
299 /* **FIXME*** */ set_Earth_position_angle( 0.0 );
301 // /* ***FIXME*** */ set_Runway_altitude( 0.0 );
303 set_sin_lat_geocentric( lat_geoc );
304 set_cos_lat_geocentric( lat_geoc );
305 set_sin_cos_longitude( lon );
306 set_sin_cos_latitude( lat_geod );
311 /******************************************************************************/