306 lines
9.6 KiB
C++
306 lines
9.6 KiB
C++
// flight.c -- a general interface to the various flight models
|
|
//
|
|
// Written by Curtis Olson, started May 1997.
|
|
//
|
|
// Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
|
|
//
|
|
// 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.
|
|
//
|
|
// $Id$
|
|
// (Log is kept at end of this file)
|
|
|
|
|
|
#include <stdio.h>
|
|
|
|
#include "flight.hxx"
|
|
#include "LaRCsim.hxx"
|
|
|
|
#include <Debug/logstream.hxx>
|
|
#include <Flight/External/external.hxx>
|
|
#include <Flight/LaRCsim/ls_interface.h>
|
|
#include <Include/fg_constants.h>
|
|
#include <Math/fg_geodesy.hxx>
|
|
#include <Time/timestamp.hxx>
|
|
|
|
|
|
// base_fdm_state is the internal state that is updated in integer
|
|
// multiples of "dt". This leads to "jitter" with respect to the real
|
|
// world time, so we introduce cur_fdm_state which is extrapolated by
|
|
// the difference between sim time and real world time
|
|
|
|
FGState cur_fdm_state;
|
|
FGState base_fdm_state;
|
|
|
|
|
|
// Extrapolate fdm based on time_offset (in usec)
|
|
void FGState::extrapolate( int time_offset ) {
|
|
double dt = time_offset / 1000000.0;
|
|
cout << "extrapolating FDM by dt = " << dt << endl;
|
|
|
|
double lat = geodetic_position_v[0] + geocentric_rates_v[0] * dt;
|
|
double lat_geoc = geocentric_position_v[0] + geocentric_rates_v[0] * dt;
|
|
|
|
double lon = geodetic_position_v[1] + geocentric_rates_v[1] * dt;
|
|
double lon_geoc = geocentric_position_v[1] + geocentric_rates_v[1] * dt;
|
|
|
|
double alt = geodetic_position_v[2] + geocentric_rates_v[2] * dt;
|
|
double radius = geocentric_position_v[2] + geocentric_rates_v[2] * dt;
|
|
|
|
geodetic_position_v[0] = lat;
|
|
geocentric_position_v[0] = lat_geoc;
|
|
|
|
geodetic_position_v[1] = lon;
|
|
geocentric_position_v[1] = lon_geoc;
|
|
|
|
geodetic_position_v[2] = alt;
|
|
geocentric_position_v[2] = radius;
|
|
}
|
|
|
|
|
|
// Initialize the flight model parameters
|
|
int fgFDMInit(int model, FGState& f, double dt) {
|
|
double save_alt = 0.0;
|
|
|
|
FG_LOG( FG_FLIGHT ,FG_INFO, "Initializing flight model" );
|
|
|
|
base_fdm_state = f;
|
|
|
|
if ( model == FGState::FG_SLEW ) {
|
|
// fgSlewInit(dt);
|
|
} else if ( model == FGState::FG_LARCSIM ) {
|
|
|
|
// lets try to avoid really screwing up the LaRCsim model
|
|
if ( base_fdm_state.get_Altitude() < -9000.0 ) {
|
|
save_alt = base_fdm_state.get_Altitude();
|
|
base_fdm_state.set_Altitude( 0.0 );
|
|
}
|
|
|
|
// translate FG to LaRCsim structure
|
|
FGState_2_LaRCsim(base_fdm_state);
|
|
|
|
// initialize LaRCsim
|
|
fgLaRCsimInit(dt);
|
|
|
|
FG_LOG( FG_FLIGHT, FG_INFO, "FG pos = " <<
|
|
base_fdm_state.get_Latitude() );
|
|
|
|
// translate LaRCsim back to FG structure
|
|
fgLaRCsim_2_FGState(base_fdm_state);
|
|
|
|
// but lets restore our original bogus altitude when we are done
|
|
if ( save_alt < -9000.0 ) {
|
|
base_fdm_state.set_Altitude( save_alt );
|
|
}
|
|
} else if ( model == FGState::FG_EXTERNAL ) {
|
|
fgExternalInit(base_fdm_state);
|
|
} else {
|
|
FG_LOG( FG_FLIGHT, FG_WARN,
|
|
"Unimplemented flight model == " << model );
|
|
}
|
|
|
|
// set valid time for this record
|
|
base_fdm_state.stamp_time();
|
|
|
|
f = base_fdm_state;
|
|
|
|
return 1;
|
|
}
|
|
|
|
|
|
// Run multiloop iterations of the flight model
|
|
int fgFDMUpdate(int model, FGState& f, int multiloop, int time_offset) {
|
|
double time_step, start_elev, end_elev;
|
|
|
|
// printf("Altitude = %.2f\n", FG_Altitude * 0.3048);
|
|
|
|
// set valid time for this record
|
|
base_fdm_state.stamp_time();
|
|
|
|
time_step = (1.0 / DEFAULT_MODEL_HZ) * multiloop;
|
|
start_elev = base_fdm_state.get_Altitude();
|
|
|
|
if ( model == FGState::FG_SLEW ) {
|
|
// fgSlewUpdate(f, multiloop);
|
|
} else if ( model == FGState::FG_LARCSIM ) {
|
|
fgLaRCsimUpdate(base_fdm_state, multiloop);
|
|
// extrapolate position based on actual time
|
|
// f = extrapolate_fdm( base_fdm_state, time_offset );
|
|
f = base_fdm_state;
|
|
} else if ( model == FGState::FG_EXTERNAL ) {
|
|
// fgExternalUpdate(f, multiloop);
|
|
FGTimeStamp current;
|
|
current.stamp();
|
|
f = base_fdm_state;
|
|
f.extrapolate( current - base_fdm_state.get_time_stamp() );
|
|
} else {
|
|
FG_LOG( FG_FLIGHT, FG_WARN,
|
|
"Unimplemented flight model == " << model );
|
|
}
|
|
|
|
end_elev = base_fdm_state.get_Altitude();
|
|
|
|
if ( time_step > 0.0 ) {
|
|
// feet per second
|
|
base_fdm_state.set_Climb_Rate( (end_elev - start_elev) / time_step );
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
|
|
// Set the altitude (force)
|
|
void fgFDMForceAltitude(int model, double alt_meters) {
|
|
double sea_level_radius_meters;
|
|
double lat_geoc;
|
|
|
|
// Set the FG variables first
|
|
fgGeodToGeoc( base_fdm_state.get_Latitude(), alt_meters,
|
|
&sea_level_radius_meters, &lat_geoc);
|
|
|
|
base_fdm_state.set_Altitude( alt_meters * METER_TO_FEET );
|
|
base_fdm_state.set_Radius_to_vehicle( base_fdm_state.get_Altitude() +
|
|
(sea_level_radius_meters *
|
|
METER_TO_FEET) );
|
|
|
|
// additional work needed for some flight models
|
|
if ( model == FGState::FG_LARCSIM ) {
|
|
ls_ForceAltitude( base_fdm_state.get_Altitude() );
|
|
}
|
|
}
|
|
|
|
|
|
// Set the local ground elevation
|
|
void fgFDMSetGroundElevation(int model, double ground_meters) {
|
|
base_fdm_state.set_Runway_altitude( ground_meters * METER_TO_FEET );
|
|
cur_fdm_state.set_Runway_altitude( ground_meters * METER_TO_FEET );
|
|
}
|
|
|
|
|
|
// $Log$
|
|
// Revision 1.13 1999/01/27 04:48:39 curt
|
|
// Set the runway height in cur_fdm_state as well as base_fdm_state.
|
|
//
|
|
// Revision 1.12 1999/01/20 13:42:22 curt
|
|
// Tweaked FDM interface.
|
|
// Testing check sum support for NMEA serial output.
|
|
//
|
|
// Revision 1.11 1999/01/19 17:52:06 curt
|
|
// Working on being able to extrapolate a new position and orientation
|
|
// based on a position, orientation, and time offset.
|
|
//
|
|
// Revision 1.10 1999/01/09 13:37:32 curt
|
|
// Convert fgTIMESTAMP to FGTimeStamp which holds usec instead of ms.
|
|
//
|
|
// Revision 1.9 1999/01/08 19:27:37 curt
|
|
// Fixed AOA reading on HUD.
|
|
// Continued work on time jitter compensation.
|
|
//
|
|
// Revision 1.8 1999/01/08 03:23:51 curt
|
|
// Beginning work on compensating for sim time vs. real world time "jitter".
|
|
//
|
|
// Revision 1.7 1998/12/18 23:37:07 curt
|
|
// Collapsed out the FGState variables not currently needed. They are just
|
|
// commented out and can be readded easily at any time. The point of this
|
|
// exersize is to determine which variables were or were not currently being
|
|
// used.
|
|
//
|
|
// Revision 1.6 1998/12/05 15:54:11 curt
|
|
// Renamed class fgFLIGHT to class FGState as per request by JSB.
|
|
//
|
|
// Revision 1.5 1998/12/04 01:29:39 curt
|
|
// Stubbed in a new flight model called "External" which is expected to be driven
|
|
// from some external source.
|
|
//
|
|
// Revision 1.4 1998/12/03 01:16:40 curt
|
|
// Converted fgFLIGHT to a class.
|
|
//
|
|
// Revision 1.3 1998/11/06 21:18:03 curt
|
|
// Converted to new logstream debugging facility. This allows release
|
|
// builds with no messages at all (and no performance impact) by using
|
|
// the -DFG_NDEBUGNDEBUG flag.
|
|
//
|
|
// Revision 1.2 1998/10/16 23:27:40 curt
|
|
// C++-ifying.
|
|
//
|
|
// Revision 1.1 1998/10/16 20:16:41 curt
|
|
// Renamed flight.[ch] to flight.[ch]xx
|
|
//
|
|
// Revision 1.19 1998/09/29 14:57:38 curt
|
|
// c++-ified comments.
|
|
//
|
|
// Revision 1.18 1998/09/29 02:02:40 curt
|
|
// Added a rate of climb calculation.
|
|
//
|
|
// Revision 1.17 1998/08/24 20:09:07 curt
|
|
// .
|
|
//
|
|
// Revision 1.16 1998/08/22 14:49:55 curt
|
|
// Attempting to iron out seg faults and crashes.
|
|
// Did some shuffling to fix a initialization order problem between view
|
|
// position, scenery elevation.
|
|
//
|
|
// Revision 1.15 1998/07/30 23:44:36 curt
|
|
// Beginning to add support for multiple flight models.
|
|
//
|
|
// Revision 1.14 1998/07/12 03:08:27 curt
|
|
// Added fgFlightModelSetAltitude() to force the altitude to something
|
|
// other than the current altitude. LaRCsim doesn't let you do this by just
|
|
// changing FG_Altitude.
|
|
//
|
|
// Revision 1.13 1998/04/25 22:06:28 curt
|
|
// Edited cvs log messages in source files ... bad bad bad!
|
|
//
|
|
// Revision 1.12 1998/04/21 16:59:33 curt
|
|
// Integrated autopilot.
|
|
// Prepairing for C++ integration.
|
|
//
|
|
// Revision 1.11 1998/04/18 04:14:04 curt
|
|
// Moved fg_debug.c to it's own library.
|
|
//
|
|
// Revision 1.10 1998/02/07 15:29:37 curt
|
|
// Incorporated HUD changes and struct/typedef changes from Charlie Hotchkiss
|
|
// <chotchkiss@namg.us.anritsu.com>
|
|
//
|
|
// Revision 1.9 1998/01/27 00:47:53 curt
|
|
// Incorporated Paul Bleisch's <pbleisch@acm.org> new debug message
|
|
// system and commandline/config file processing code.
|
|
//
|
|
// Revision 1.8 1998/01/19 19:27:03 curt
|
|
// Merged in make system changes from Bob Kuehne <rpk@sgi.com>
|
|
// This should simplify things tremendously.
|
|
//
|
|
// Revision 1.7 1998/01/19 18:40:23 curt
|
|
// Tons of little changes to clean up the code and to remove fatal errors
|
|
// when building with the c++ compiler.
|
|
//
|
|
// Revision 1.6 1998/01/19 18:35:43 curt
|
|
// Minor tweaks and fixes for cygwin32.
|
|
//
|
|
// Revision 1.5 1997/12/30 20:47:37 curt
|
|
// Integrated new event manager with subsystem initializations.
|
|
//
|
|
// Revision 1.4 1997/12/10 22:37:42 curt
|
|
// Prepended "fg" on the name of all global structures that didn't have it yet.
|
|
// i.e. "struct WEATHER {}" became "struct fgWEATHER {}"
|
|
//
|
|
// Revision 1.3 1997/08/27 03:30:04 curt
|
|
// Changed naming scheme of basic shared structures.
|
|
//
|
|
// Revision 1.2 1997/05/29 22:39:57 curt
|
|
// Working on incorporating the LaRCsim flight model.
|
|
//
|
|
// Revision 1.1 1997/05/29 02:35:04 curt
|
|
// Initial revision.
|
|
//
|