src/FDM/JSBSim.cxx

   1 // JSBsim.cxx -- interface to the JSBsim flight model
   2 //
   3 // Written by Curtis Olson, started February 1999.
   4 //
   5 // Copyright (C) 1999  Curtis L. Olson  - curt@flightgear.org
   6 //
   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.
  11 //
  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.
  16 //
  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.
  20 //
  21 // $Id$
  22
  23
  24 #include <simgear/compiler.h>
  25
  26 #ifdef FG_MATH_EXCEPTION_CLASH
  27 #  include <math.h>
  28 #endif
  29
  30 #include STL_STRING
  31
  32 #include <simgear/constants.h>
  33 #include <simgear/debug/logstream.hxx>
  34 #include <simgear/math/sg_geodesy.hxx>
  35 #include <simgear/misc/fgpath.hxx>
  36
  37 #include <Scenery/scenery.hxx>
  38
  39 #include <Aircraft/aircraft.hxx>
  40 #include <Controls/controls.hxx>
  41 #include <Main/options.hxx>
  42
  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/FGAtmosphere.h>
  54
  55 #include "JSBSim.hxx"
  56
  57 /******************************************************************************/
  58
  59 // Initialize the JSBsim flight model, dt is the time increment for
  60 // each subsequent iteration through the EOM
  61
  62 int FGJSBsim::init( double dt ) {
  63
  64   bool result;
  65
  66   FG_LOG( FG_FLIGHT, FG_INFO, "Starting and initializing JSBsim" );
  67   FG_LOG( FG_FLIGHT, FG_INFO, "  created FDMExec" );
  68
  69   FGPath aircraft_path( current_options.get_fg_root() );
  70   aircraft_path.append( "Aircraft" );
  71
  72   FGPath engine_path( current_options.get_fg_root() );
  73   engine_path.append( "Engine" );
  74
  75   FDMExec.GetState()->Setdt( dt );
  76
  77   result = FDMExec.LoadModel( aircraft_path.str(),
  78                                        engine_path.str(),
  79                                        current_options.get_aircraft() );
  80
  81   if (result) {
  82     FG_LOG( FG_FLIGHT, FG_INFO, "  loaded aircraft" << current_options.get_aircraft() );
  83   } else {
  84     FG_LOG( FG_FLIGHT, FG_INFO, "  aircraft" << current_options.get_aircraft()
  85                                 << " does not exist");
  86     return 0;
  87   }
  88
  89   FDMExec.GetAtmosphere()->SetExTemperature(get_Static_temperature());
  90   FDMExec.GetAtmosphere()->SetExPressure(get_Static_pressure());
  91   FDMExec.GetAtmosphere()->SetExDensity(get_Density());
  92   FDMExec.GetAtmosphere()->SetWindNED(get_V_north_airmass(),
  93                                       get_V_east_airmass(),
  94                                       get_V_down_airmass());
  95
  96   FDMExec.GetAtmosphere()->UseInternal();
  97
  98   FG_LOG( FG_FLIGHT, FG_INFO, "  Initializing JSBSim with:" );
  99
 100   FGInitialCondition *fgic = new FGInitialCondition(&FDMExec);
 101   fgic->SetAltitudeFtIC(get_Altitude());
 102   if((current_options.get_mach() < 0) && (current_options.get_vc() < 0 )) {
 103     fgic->SetUBodyFpsIC(current_options.get_uBody());
 104     fgic->SetVBodyFpsIC(current_options.get_vBody());
 105     fgic->SetWBodyFpsIC(current_options.get_wBody());
 106     FG_LOG(FG_FLIGHT,FG_INFO, "  u,v,w= " << current_options.get_uBody()
 107            << ", " << current_options.get_vBody()
 108            << ", " << current_options.get_wBody());
 109   } else if (current_options.get_vc() < 0) {
 110     fgic->SetMachIC(current_options.get_mach());
 111     FG_LOG(FG_FLIGHT,FG_INFO, "  mach: " << current_options.get_mach() );
 112   } else {
 113     fgic->SetVcalibratedKtsIC(current_options.get_vc());
 114     FG_LOG(FG_FLIGHT,FG_INFO, "  vc: " << current_options.get_vc() );
 115     //this should cover the case in which no speed switches are used
 116     //current_options.get_vc() will return zero by default
 117   }
 118
 119
 120   fgic->SetRollAngleRadIC(get_Phi());
 121   fgic->SetPitchAngleRadIC(get_Theta());
 122   fgic->SetHeadingRadIC(get_Psi());
 123 //  fgic->SetLatitudeRadIC(get_Latitude());
 124   fgic->SetLatitudeRadIC(get_Lat_geocentric());
 125   fgic->SetLongitudeRadIC(get_Longitude());
 126
 127   FDMExec.GetPosition()->SetRunwayRadius(scenery.cur_radius*METER_TO_FEET);
 128   FDMExec.GetPosition()->SetSeaLevelRadius(get_Sea_level_radius());
 129   FDMExec.GetPosition()->SetRunwayNormal( scenery.cur_normal[0],
 130                                           scenery.cur_normal[1],
 131                                           scenery.cur_normal[2] );
 132
 133   FG_LOG( FG_FLIGHT, FG_INFO, "  phi: " <<  get_Phi());
 134   FG_LOG( FG_FLIGHT, FG_INFO, "  theta: " <<  get_Theta() );
 135   FG_LOG( FG_FLIGHT, FG_INFO, "  psi: " <<  get_Psi() );
 136   FG_LOG( FG_FLIGHT, FG_INFO, "  lat: " <<  get_Latitude() );
 137   FG_LOG( FG_FLIGHT, FG_INFO, "  lon: " <<  get_Longitude() );
 138   FG_LOG( FG_FLIGHT, FG_INFO, "  alt: " <<  get_Altitude() );
 139
 140   //must check > 0, != 0 will give bad result if --notrim set
 141   if(current_options.get_trim_mode() > 0) {
 142     FDMExec.RunIC(fgic);
 143     FG_LOG( FG_FLIGHT, FG_INFO, "  Starting trim..." );
 144 //    FGTrimLong *fgtrim=new FGTrimLong(&FDMExec,fgic);
 145 //    fgtrim->DoTrim();
 146 //    fgtrim->Report();
 147 //    fgtrim->TrimStats();
 148 //    fgtrim->ReportState();
 149
 150     controls.set_elevator_trim(FDMExec.GetFCS()->GetPitchTrimCmd());
 151     controls.set_throttle(FGControls::ALL_ENGINES,FDMExec.GetFCS()->GetThrottleCmd(0)/100);
 152     //the trimming routine only knows how to get 1 value for throttle
 153
 154 //    delete fgtrim;
 155     FG_LOG( FG_FLIGHT, FG_INFO, "  Trim complete." );
 156   } else {
 157     FG_LOG( FG_FLIGHT, FG_INFO, "  Initializing without trim" );
 158     FDMExec.GetState()->Initialize(fgic);
 159
 160   }
 161
 162   delete fgic;
 163
 164   FG_LOG( FG_FLIGHT, FG_INFO, "  loaded initial conditions" );
 165
 166   FG_LOG( FG_FLIGHT, FG_INFO, "  set dt" );
 167
 168   FG_LOG( FG_FLIGHT, FG_INFO, "Finished initializing JSBSim" );
 169
 170   copy_from_JSBsim();
 171
 172   return 1;
 173 }
 174
 175 /******************************************************************************/
 176
 177 // Run an iteration of the EOM (equations of motion)
 178
 179 int FGJSBsim::update( int multiloop ) {
 180   double save_alt = 0.0;
 181   double time_step = (1.0 / current_options.get_model_hz()) * multiloop;
 182   double start_elev = get_Altitude();
 183
 184   // lets try to avoid really screwing up the JSBsim model
 185   if ( get_Altitude() < -9000 ) {
 186     save_alt = get_Altitude();
 187     set_Altitude( 0.0 );
 188   }
 189
 190   // copy control positions into the JSBsim structure
 191
 192   FDMExec.GetFCS()->SetDaCmd( controls.get_aileron());
 193   FDMExec.GetFCS()->SetDeCmd( controls.get_elevator());
 194   FDMExec.GetFCS()->SetPitchTrimCmd(controls.get_elevator_trim());
 195   FDMExec.GetFCS()->SetDrCmd( controls.get_rudder());
 196   FDMExec.GetFCS()->SetDfCmd( controls.get_flaps() );
 197   FDMExec.GetFCS()->SetDsbCmd( 0.0 ); //speedbrakes
 198   FDMExec.GetFCS()->SetDspCmd( 0.0 ); //spoilers
 199   FDMExec.GetFCS()->SetThrottleCmd( FGControls::ALL_ENGINES,
 200                                     controls.get_throttle( 0 ) * 100.0 );
 201
 202   // FCS->SetBrake( controls.get_brake( 0 ) );
 203
 204   // Inform JSBsim of the local terrain altitude; uncommented 5/3/00
 205   //  FDMExec.GetPosition()->SetRunwayElevation(get_Runway_altitude()); // seems to work
 206   FDMExec.GetPosition()->SetRunwayRadius(scenery.cur_radius*METER_TO_FEET);
 207   FDMExec.GetPosition()->SetSeaLevelRadius(get_Sea_level_radius());
 208   FDMExec.GetPosition()->SetRunwayNormal( scenery.cur_normal[0],
 209                                           scenery.cur_normal[1],
 210                                           scenery.cur_normal[2] );
 211
 212   FDMExec.GetAtmosphere()->SetExTemperature(get_Static_temperature());
 213   FDMExec.GetAtmosphere()->SetExPressure(get_Static_pressure());
 214   FDMExec.GetAtmosphere()->SetExDensity(get_Density());
 215   FDMExec.GetAtmosphere()->SetWindNED(get_V_north_airmass(),
 216                                       get_V_east_airmass(),
 217                                       get_V_down_airmass());
 218
 219   for ( int i = 0; i < multiloop; i++ ) {
 220     FDMExec.Run();
 221   }
 222
 223   // printf("%d FG_Altitude = %.2f\n", i, FG_Altitude * 0.3048);
 224   // printf("%d Altitude = %.2f\n", i, Altitude * 0.3048);
 225
 226   // translate JSBsim back to FG structure so that the
 227   // autopilot (and the rest of the sim can use the updated values
 228
 229   copy_from_JSBsim();
 230
 231   // but lets restore our original bogus altitude when we are done
 232
 233   if ( save_alt < -9000.0 ) {
 234     set_Altitude( save_alt );
 235   }
 236
 237   double end_elev = get_Altitude();
 238   //if ( time_step > 0.0 ) {
 239     // feet per second
 240   //  set_Climb_Rate( (end_elev - start_elev) / time_step );
 241   //}
 242
 243   return 1;
 244 }
 245
 246 /******************************************************************************/
 247
 248 // Convert from the FGInterface struct to the JSBsim generic_ struct
 249
 250 int FGJSBsim::copy_to_JSBsim() {
 251   return 1;
 252 }
 253
 254 /******************************************************************************/
 255
 256 // Convert from the JSBsim generic_ struct to the FGInterface struct
 257
 258 int FGJSBsim::copy_from_JSBsim() {
 259
 260   set_Inertias( FDMExec.GetAircraft()->GetMass(),
 261                 FDMExec.GetAircraft()->GetIxx(),
 262                 FDMExec.GetAircraft()->GetIyy(),
 263                 FDMExec.GetAircraft()->GetIzz(),
 264                 FDMExec.GetAircraft()->GetIxz() );
 265
 266   set_CG_Position ( FDMExec.GetAircraft()->GetXYZcg()(1),
 267                     FDMExec.GetAircraft()->GetXYZcg()(2),
 268                     FDMExec.GetAircraft()->GetXYZcg()(3) );
 269
 270   set_Accels_Body ( FDMExec.GetTranslation()->GetUVWdot()(1),
 271                     FDMExec.GetTranslation()->GetUVWdot()(2),
 272                     FDMExec.GetTranslation()->GetUVWdot()(3) );
 273
 274   set_Accels_CG_Body ( FDMExec.GetTranslation()->GetUVWdot()(1),
 275                        FDMExec.GetTranslation()->GetUVWdot()(2),
 276                        FDMExec.GetTranslation()->GetUVWdot()(3) );
 277
 278   //set_Accels_CG_Body_N ( FDMExec.GetTranslation()->GetNcg()(1),
 279   //                       FDMExec.GetTranslation()->GetNcg()(2),
 280   //                       FDMExec.GetTranslation()->GetNcg()(3) );
 281   //
 282   set_Accels_Pilot_Body( FDMExec.GetAuxiliary()->GetPilotAccel()(1),
 283                          FDMExec.GetAuxiliary()->GetPilotAccel()(2),
 284                          FDMExec.GetAuxiliary()->GetPilotAccel()(3) );
 285
 286   //set_Accels_Pilot_Body_N( FDMExec.GetAuxiliary()->GetNpilot()(1),
 287   //                         FDMExec.GetAuxiliary()->GetNpilot()(2),
 288   //                         FDMExec.GetAuxiliary()->GetNpilot()(3) );
 289
 290
 291
 292   set_Nlf( FDMExec.GetAircraft()->GetNlf());
 293
 294
 295
 296   // Velocities
 297
 298   set_Velocities_Local( FDMExec.GetPosition()->GetVn(),
 299                         FDMExec.GetPosition()->GetVe(),
 300                         FDMExec.GetPosition()->GetVd() );
 301
 302   set_Velocities_Wind_Body( FDMExec.GetTranslation()->GetUVW()(1),
 303                             FDMExec.GetTranslation()->GetUVW()(2),
 304                             FDMExec.GetTranslation()->GetUVW()(3)  );
 305
 306   set_V_equiv_kts( FDMExec.GetAuxiliary()->GetVequivalentKTS() );
 307
 308   //set_V_calibrated( FDMExec.GetAuxiliary()->GetVcalibratedFPS() );
 309
 310   set_V_calibrated_kts( FDMExec.GetAuxiliary()->GetVcalibratedKTS() );
 311
 312   set_V_ground_speed ( FDMExec.GetPosition()->GetVground() );
 313
 314   set_Omega_Body( FDMExec.GetState()->GetParameter(FG_ROLLRATE),
 315                   FDMExec.GetState()->GetParameter(FG_PITCHRATE),
 316                   FDMExec.GetState()->GetParameter(FG_YAWRATE) );
 317
 318   /* HUH!?! */ set_Euler_Rates( FDMExec.GetRotation()->Getphi(),
 319                    FDMExec.GetRotation()->Gettht(),
 320                    FDMExec.GetRotation()->Getpsi() );
 321
 322   // ***FIXME*** set_Geocentric_Rates( Latitude_dot, Longitude_dot, Radius_dot );
 323
 324   set_Mach_number( FDMExec.GetTranslation()->GetMach());
 325
 326   // Positions
 327
 328   double lat_geoc = FDMExec.GetPosition()->GetLatitude();
 329   double lon = FDMExec.GetPosition()->GetLongitude();
 330   double alt = FDMExec.GetPosition()->Geth();
 331   double lat_geod, tmp_alt, sl_radius1, sl_radius2, tmp_lat_geoc;
 332
 333   sgGeocToGeod( lat_geoc, EQUATORIAL_RADIUS_M + alt * FEET_TO_METER,
 334                 &lat_geod, &tmp_alt, &sl_radius1 );
 335   sgGeodToGeoc( lat_geod, alt * FEET_TO_METER, &sl_radius2, &tmp_lat_geoc );
 336
 337   FG_LOG( FG_FLIGHT, FG_DEBUG, "lon = " << lon << " lat_geod = " << lat_geod
 338           << " lat_geoc = " << lat_geoc
 339           << " alt = " << alt << " tmp_alt = " << tmp_alt * METER_TO_FEET
 340           << " sl_radius1 = " << sl_radius1 * METER_TO_FEET
 341           << " sl_radius2 = " << sl_radius2 * METER_TO_FEET
 342           << " Equator = " << EQUATORIAL_RADIUS_FT );
 343
 344   set_Geocentric_Position( lat_geoc, lon,
 345                            sl_radius2 * METER_TO_FEET + alt );
 346   set_Geodetic_Position( lat_geod, lon, alt );
 347   set_Euler_Angles( FDMExec.GetRotation()->Getphi(),
 348                     FDMExec.GetRotation()->Gettht(),
 349                     FDMExec.GetRotation()->Getpsi() );
 350
 351   set_Alpha( FDMExec.GetTranslation()->Getalpha() );
 352   set_Beta( FDMExec.GetTranslation()->Getbeta() );
 353
 354   set_Gamma_vert_rad( FDMExec.GetPosition()->GetGamma() );
 355   // set_Gamma_horiz_rad( Gamma_horiz_rad );
 356
 357   /* **FIXME*** */ set_Sea_level_radius( sl_radius2 * METER_TO_FEET );
 358   /* **FIXME*** */ set_Earth_position_angle( 0.0 );
 359
 360   // /* ***FIXME*** */ set_Runway_altitude( 0.0 );
 361
 362   set_sin_lat_geocentric( lat_geoc );
 363   set_cos_lat_geocentric( lat_geoc );
 364   set_sin_cos_longitude( lon );
 365   set_sin_cos_latitude( lat_geod );
 366
 367   set_Climb_Rate(FDMExec.GetPosition()->Gethdot());
 368
 369   return 1;
 370 }