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flightgear/src/FDM/JSBSim.cxx

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// JSBsim.cxx -- interface to the JSBsim flight model
//
// Written by Curtis Olson, started February 1999.
//
// Copyright (C) 1999 Curtis L. Olson - curt@flightgear.org
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
//
// $Id$
#include <simgear/compiler.h>
#ifdef FG_MATH_EXCEPTION_CLASH
# include <math.h>
#endif
#include STL_STRING
#include <simgear/constants.h>
#include <simgear/debug/logstream.hxx>
#include <simgear/math/sg_geodesy.hxx>
#include <simgear/misc/fgpath.hxx>
#include <Scenery/scenery.hxx>
#include <Aircraft/aircraft.hxx>
#include <Controls/controls.hxx>
#include <Main/options.hxx>
#include <FDM/JSBSim/FGFDMExec.h>
#include <FDM/JSBSim/FGAircraft.h>
#include <FDM/JSBSim/FGFCS.h>
#include <FDM/JSBSim/FGPosition.h>
#include <FDM/JSBSim/FGRotation.h>
#include <FDM/JSBSim/FGState.h>
#include <FDM/JSBSim/FGTranslation.h>
#include <FDM/JSBSim/FGAuxiliary.h>
#include <FDM/JSBSim/FGDefs.h>
#include <FDM/JSBSim/FGInitialCondition.h>
#include <FDM/JSBSim/FGTrim.h>
#include <FDM/JSBSim/FGAtmosphere.h>
#include "JSBSim.hxx"
/******************************************************************************/
// Initialize the JSBsim flight model, dt is the time increment for
// each subsequent iteration through the EOM
bool FGJSBsim::init( double dt ) {
bool result;
FG_LOG( FG_FLIGHT, FG_INFO, "Starting and initializing JSBsim" );
FG_LOG( FG_FLIGHT, FG_INFO, " created FDMExec" );
FGPath aircraft_path( current_options.get_fg_root() );
aircraft_path.append( "Aircraft" );
FGPath engine_path( current_options.get_fg_root() );
engine_path.append( "Engine" );
//FDMExec.GetState()->Setdt( dt );
result = FDMExec.LoadModel( aircraft_path.str(),
engine_path.str(),
current_options.get_aircraft() );
FDMExec.GetState()->Setdt( dt );
if (result) {
FG_LOG( FG_FLIGHT, FG_INFO, " loaded aircraft " << current_options.get_aircraft() );
} else {
FG_LOG( FG_FLIGHT, FG_INFO, " aircraft " << current_options.get_aircraft()
<< " does not exist" );
return false;
}
FDMExec.GetAtmosphere()->SetExTemperature(get_Static_temperature());
FDMExec.GetAtmosphere()->SetExPressure(get_Static_pressure());
FDMExec.GetAtmosphere()->SetExDensity(get_Density());
FDMExec.GetAtmosphere()->SetWindNED(get_V_north_airmass(),
get_V_east_airmass(),
get_V_down_airmass());
FDMExec.GetAtmosphere()->UseInternal();
FDMExec.GetPosition()->SetRunwayRadius(scenery.cur_radius*METER_TO_FEET);
FDMExec.GetPosition()->SetSeaLevelRadius(get_Sea_level_radius());
FG_LOG( FG_FLIGHT, FG_INFO, " Initializing JSBSim with:" );
FGInitialCondition *fgic = new FGInitialCondition(&FDMExec);
fgic->SetAltitudeFtIC(get_Altitude());
if((current_options.get_mach() < 0) && (current_options.get_vc() < 0 )) {
fgic->SetUBodyFpsIC(current_options.get_uBody());
fgic->SetVBodyFpsIC(current_options.get_vBody());
fgic->SetWBodyFpsIC(current_options.get_wBody());
FG_LOG(FG_FLIGHT,FG_INFO, " u,v,w= " << current_options.get_uBody()
<< ", " << current_options.get_vBody()
<< ", " << current_options.get_wBody());
} else if (current_options.get_vc() < 0) {
fgic->SetMachIC(current_options.get_mach());
FG_LOG(FG_FLIGHT,FG_INFO, " mach: " << current_options.get_mach() );
} else {
fgic->SetVcalibratedKtsIC(current_options.get_vc());
FG_LOG(FG_FLIGHT,FG_INFO, " vc: " << current_options.get_vc() );
//this should cover the case in which no speed switches are used
//current_options.get_vc() will return zero by default
}
//fgic->SetFlightPathAngleDegIC(current_options.get_Gamma());
fgic->SetRollAngleRadIC(get_Phi());
fgic->SetPitchAngleRadIC(get_Theta());
fgic->SetHeadingRadIC(get_Psi());
fgic->SetLatitudeRadIC(get_Lat_geocentric());
fgic->SetLongitudeRadIC(get_Longitude());
//FG_LOG( FG_FLIGHT, FG_INFO, " gamma: " << current_options.get_Gamma());
FG_LOG( FG_FLIGHT, FG_INFO, " phi: " << get_Phi());
//FG_LOG( FG_FLIGHT, FG_INFO, " theta: " << get_Theta() );
FG_LOG( FG_FLIGHT, FG_INFO, " psi: " << get_Psi() );
FG_LOG( FG_FLIGHT, FG_INFO, " lat: " << get_Latitude() );
FG_LOG( FG_FLIGHT, FG_INFO, " lon: " << get_Longitude() );
FG_LOG( FG_FLIGHT, FG_INFO, " Pressure Altiude: " << get_Altitude() );
FG_LOG( FG_FLIGHT, FG_INFO, " Terrain Altitude: "
<< scenery.cur_radius*METER_TO_FEET );
FG_LOG( FG_FLIGHT, FG_INFO, " AGL Altitude: "
<< get_Altitude() + get_Sea_level_radius()
- scenery.cur_radius*METER_TO_FEET );
FG_LOG( FG_FLIGHT, FG_INFO, " current_options.get_altitude(): "
<< current_options.get_altitude() );
//must check > 0, != 0 will give bad result if --notrim set
if(current_options.get_trim_mode() > 0) {
if(fgic->GetVcalibratedKtsIC() > 50) {
FDMExec.RunIC(fgic);
FG_LOG( FG_FLIGHT, FG_INFO, " Starting trim..." );
FGTrim *fgtrim=new FGTrim(&FDMExec,fgic,tLongitudinal);
fgtrim->DoTrim();
fgtrim->Report();
fgtrim->TrimStats();
fgtrim->ReportState();
controls.set_elevator_trim(FDMExec.GetFCS()->GetPitchTrimCmd());
controls.set_throttle(FGControls::ALL_ENGINES,FDMExec.GetFCS()->GetThrottleCmd(0)/100);
trimmed=true;
trim_elev=FDMExec.GetFCS()->GetPitchTrimCmd();
trim_throttle=FDMExec.GetFCS()->GetThrottleCmd(0)/100;
//the trimming routine only knows how to get 1 value for throttle
delete fgtrim;
}
FG_LOG( FG_FLIGHT, FG_INFO, " Trim complete." );
} else {
FG_LOG( FG_FLIGHT, FG_INFO, " Initializing without trim" );
FDMExec.GetState()->Initialize(fgic);
}
delete fgic;
FG_LOG( FG_FLIGHT, FG_INFO, " loaded initial conditions" );
FG_LOG( FG_FLIGHT, FG_INFO, " set dt" );
FG_LOG( FG_FLIGHT, FG_INFO, "Finished initializing JSBSim" );
copy_from_JSBsim();
return true;
}
/******************************************************************************/
// Run an iteration of the EOM (equations of motion)
bool FGJSBsim::update( int multiloop ) {
double save_alt = 0.0;
double time_step = (1.0 / current_options.get_model_hz()) * multiloop;
double start_elev = get_Altitude();
// lets try to avoid really screwing up the JSBsim model
if ( get_Altitude() < -9000 ) {
save_alt = get_Altitude();
set_Altitude( 0.0 );
}
if(trimmed) {
controls.set_elevator_trim(trim_elev);
controls.set_throttle(FGControls::ALL_ENGINES,trim_throttle);
controls.set_elevator(0.0);
controls.set_aileron(0.0);
controls.set_rudder(0.0);
trimmed=false;
}
copy_to_JSBsim();
for ( int i = 0; i < multiloop; i++ ) {
FDMExec.Run();
}
// printf("%d FG_Altitude = %.2f\n", i, FG_Altitude * 0.3048);
// printf("%d Altitude = %.2f\n", i, Altitude * 0.3048);
// translate JSBsim back to FG structure so that the
// autopilot (and the rest of the sim can use the updated values
copy_from_JSBsim();
// but lets restore our original bogus altitude when we are done
if ( save_alt < -9000.0 ) {
set_Altitude( save_alt );
}
double end_elev = get_Altitude();
return true;
}
/******************************************************************************/
// Convert from the FGInterface struct to the JSBsim generic_ struct
bool FGJSBsim::copy_to_JSBsim() {
// copy control positions into the JSBsim structure
FDMExec.GetFCS()->SetDaCmd( controls.get_aileron());
FDMExec.GetFCS()->SetDeCmd( controls.get_elevator());
FDMExec.GetFCS()->SetPitchTrimCmd(controls.get_elevator_trim());
FDMExec.GetFCS()->SetDrCmd( -1*controls.get_rudder());
FDMExec.GetFCS()->SetDfCmd( controls.get_flaps() );
FDMExec.GetFCS()->SetDsbCmd( 0.0 ); //speedbrakes
FDMExec.GetFCS()->SetDspCmd( 0.0 ); //spoilers
FDMExec.GetFCS()->SetThrottleCmd( FGControls::ALL_ENGINES,
controls.get_throttle( 0 ) * 100.0 );
FDMExec.GetFCS()->SetLBrake( controls.get_brake( 0 ) );
FDMExec.GetFCS()->SetRBrake( controls.get_brake( 1 ) );
FDMExec.GetFCS()->SetCBrake( controls.get_brake( 2 ) );
// Inform JSBsim of the local terrain altitude; uncommented 5/3/00
// FDMExec.GetPosition()->SetRunwayElevation(get_Runway_altitude()); // seems to work
FDMExec.GetPosition()->SetRunwayRadius(scenery.cur_radius*METER_TO_FEET);
FDMExec.GetPosition()->SetSeaLevelRadius(get_Sea_level_radius());
FDMExec.GetAtmosphere()->SetExTemperature(get_Static_temperature());
FDMExec.GetAtmosphere()->SetExPressure(get_Static_pressure());
FDMExec.GetAtmosphere()->SetExDensity(get_Density());
FDMExec.GetAtmosphere()->SetWindNED(get_V_north_airmass(),
get_V_east_airmass(),
get_V_down_airmass());
return true;
}
/******************************************************************************/
// Convert from the JSBsim generic_ struct to the FGInterface struct
bool FGJSBsim::copy_from_JSBsim() {
set_Inertias( FDMExec.GetAircraft()->GetMass(),
FDMExec.GetAircraft()->GetIxx(),
FDMExec.GetAircraft()->GetIyy(),
FDMExec.GetAircraft()->GetIzz(),
FDMExec.GetAircraft()->GetIxz() );
set_CG_Position ( FDMExec.GetAircraft()->GetXYZcg()(1),
FDMExec.GetAircraft()->GetXYZcg()(2),
FDMExec.GetAircraft()->GetXYZcg()(3) );
set_Accels_Body ( FDMExec.GetTranslation()->GetUVWdot()(1),
FDMExec.GetTranslation()->GetUVWdot()(2),
FDMExec.GetTranslation()->GetUVWdot()(3) );
set_Accels_CG_Body ( FDMExec.GetTranslation()->GetUVWdot()(1),
FDMExec.GetTranslation()->GetUVWdot()(2),
FDMExec.GetTranslation()->GetUVWdot()(3) );
//set_Accels_CG_Body_N ( FDMExec.GetTranslation()->GetNcg()(1),
// FDMExec.GetTranslation()->GetNcg()(2),
// FDMExec.GetTranslation()->GetNcg()(3) );
//
set_Accels_Pilot_Body( FDMExec.GetAuxiliary()->GetPilotAccel()(1),
FDMExec.GetAuxiliary()->GetPilotAccel()(2),
FDMExec.GetAuxiliary()->GetPilotAccel()(3) );
//set_Accels_Pilot_Body_N( FDMExec.GetAuxiliary()->GetNpilot()(1),
// FDMExec.GetAuxiliary()->GetNpilot()(2),
// FDMExec.GetAuxiliary()->GetNpilot()(3) );
set_Nlf( FDMExec.GetAircraft()->GetNlf());
// Velocities
set_Velocities_Local( FDMExec.GetPosition()->GetVn(),
FDMExec.GetPosition()->GetVe(),
FDMExec.GetPosition()->GetVd() );
set_Velocities_Wind_Body( FDMExec.GetTranslation()->GetUVW()(1),
FDMExec.GetTranslation()->GetUVW()(2),
FDMExec.GetTranslation()->GetUVW()(3) );
set_V_equiv_kts( FDMExec.GetAuxiliary()->GetVequivalentKTS() );
//set_V_calibrated( FDMExec.GetAuxiliary()->GetVcalibratedFPS() );
set_V_calibrated_kts( FDMExec.GetAuxiliary()->GetVcalibratedKTS() );
set_V_ground_speed ( FDMExec.GetPosition()->GetVground() );
set_Omega_Body( FDMExec.GetState()->GetParameter(FG_ROLLRATE),
FDMExec.GetState()->GetParameter(FG_PITCHRATE),
FDMExec.GetState()->GetParameter(FG_YAWRATE) );
set_Euler_Rates( FDMExec.GetRotation()->GetEulerRates()(2),
FDMExec.GetRotation()->GetEulerRates()(1),
FDMExec.GetRotation()->GetEulerRates()(3));
// ***FIXME*** set_Geocentric_Rates( Latitude_dot, Longitude_dot, Radius_dot );
set_Mach_number( FDMExec.GetTranslation()->GetMach());
// Positions
double lat_geoc = FDMExec.GetPosition()->GetLatitude();
double lon = FDMExec.GetPosition()->GetLongitude();
double alt = FDMExec.GetPosition()->Geth();
double lat_geod, tmp_alt, sl_radius1, sl_radius2, tmp_lat_geoc;
sgGeocToGeod( lat_geoc, EQUATORIAL_RADIUS_M + alt * FEET_TO_METER,
&lat_geod, &tmp_alt, &sl_radius1 );
sgGeodToGeoc( lat_geod, alt * FEET_TO_METER, &sl_radius2, &tmp_lat_geoc );
FG_LOG( FG_FLIGHT, FG_DEBUG, "lon = " << lon << " lat_geod = " << lat_geod
<< " lat_geoc = " << lat_geoc
<< " alt = " << alt << " tmp_alt = " << tmp_alt * METER_TO_FEET
<< " sl_radius1 = " << sl_radius1 * METER_TO_FEET
<< " sl_radius2 = " << sl_radius2 * METER_TO_FEET
<< " Equator = " << EQUATORIAL_RADIUS_FT );
set_Geocentric_Position( lat_geoc, lon,
sl_radius2 * METER_TO_FEET + alt );
set_Geodetic_Position( lat_geod, lon, alt );
set_Euler_Angles( FDMExec.GetRotation()->Getphi(),
FDMExec.GetRotation()->Gettht(),
FDMExec.GetRotation()->Getpsi() );
set_Alpha( FDMExec.GetTranslation()->Getalpha() );
set_Beta( FDMExec.GetTranslation()->Getbeta() );
set_Gamma_vert_rad( FDMExec.GetPosition()->GetGamma() );
// set_Gamma_horiz_rad( Gamma_horiz_rad );
/* **FIXME*** */ set_Sea_level_radius( sl_radius2 * METER_TO_FEET );
/* **FIXME*** */ set_Earth_position_angle( 0.0 );
// /* ***FIXME*** */ set_Runway_altitude( 0.0 );
set_sin_lat_geocentric( lat_geoc );
set_cos_lat_geocentric( lat_geoc );
set_sin_cos_longitude( lon );
set_sin_cos_latitude( lat_geod );
set_Climb_Rate(FDMExec.GetPosition()->Gethdot());
return true;
}
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