-// slew.cxx -- the "slew" flight model
+// external.cxx -- externally driven flight model
//
-// Written by Curtis Olson, started May 1997.
+// Written by Curtis Olson, started January 1998.
//
-// Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
+// Copyright (C) 1998 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
// reset flight params to a specific position
-void fgExternalInit( FGState &f, double dt ) {
-
+void fgExternalInit( FGState &f ) {
}
// $Log$
+// Revision 1.3 1999/01/19 17:52:11 curt
+// Working on being able to extrapolate a new position and orientation
+// based on a position, orientation, and time offset.
+//
// Revision 1.2 1998/12/05 15:54:13 curt
// Renamed class fgFLIGHT to class FGState as per request by JSB.
//
#include <Time/timestamp.hxx>
+/*
class fgFDM_EXTERNAL {
public:
// Velocities
- // velocity relative to the local aircraft's coordinate system
- double V_north;
- double V_east;
- double V_down;
-
- // rotational rates relative to the coordinate system the body lives in
- double P_body;
- double Q_body;
- double R_body;
-
- // Accelerations
-
- // acceleration relative to the local aircraft's coordinate system
- double V_dot_north;
- double V_dot_east;
- double V_dot_down;
-
- // rotational acceleration relative to the coordinate system the
- // body lives in
- double P_dot_body;
- double Q_dot_body;
- double R_dot_body;
+ // velocities in geodetic coordinates
+ double Latitude_dot; // rad/sec
+ double Longitude_dot; // rad/sec
+ double Altitude_dot; // feet/sec
+
+ // rotational rates
+ double Phi_dot;
+ double Theta_dot;
+ double Psi_dot;
};
+*/
// reset flight params to a specific position
-void fgExternalInit( FGState& f, double dt );
-
-// update position based on inputs, positions, velocities, etc.
-void fgExternalUpdate( FGState& f, int multiloop );
+void fgExternalInit( FGState& f );
#endif // _EXTERNAL_HXX
// $Log$
+// Revision 1.5 1999/01/19 17:52:12 curt
+// Working on being able to extrapolate a new position and orientation
+// based on a position, orientation, and time offset.
+//
// Revision 1.4 1999/01/09 13:37:37 curt
// Convert fgTIMESTAMP to FGTimeStamp which holds usec instead of ms.
//
#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
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 fgFlightModelInit(int model, FGState& f, double dt) {
double save_alt = 0.0;
base_fdm_state.set_Altitude( save_alt );
}
} else if ( model == FGState::FG_EXTERNAL ) {
- fgExternalInit(base_fdm_state, dt);
+ 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;
}
-// Extrapolate fdm based on jitter time (in milliseconds)
-static FGState extrapolate_fdm( FGState &base, int jitter ) {
- FGState result;
-
- double dt = jitter / 1000000.0;
- // cout << "dt = " << dt << endl;
-
- // start by making a straight up copy
- result = base;
-
- double lon = base.get_Longitude() + base.get_Longitude_dot() * dt;
- double lon_geoc = base.get_Lon_geocentric() + base.get_Longitude_dot() * dt;
-
- double lat = base.get_Latitude() + base.get_Latitude_dot() * dt;
- double lat_geoc = base.get_Lat_geocentric() + base.get_Latitude_dot() * dt;
-
- /*
- cout << "( " << base.get_Longitude() << ", " <<
- base.get_Latitude() << " )" << endl;
- cout << "( " << lon << ", " << lat << " )" << endl;
- cout << "( " << base.get_Longitude_dot() * dt << ", " <<
- base.get_Latitude_dot() * dt << ", " <<
- base.get_Radius_dot() * dt << " )" << endl;
- */
-
- double alt = base.get_Altitude() + base.get_Radius_dot() * dt;
- double radius = base.get_Radius_to_vehicle() + base.get_Radius_dot() * dt;
-
- // result.set_Longitude( lon );
- // result.set_Latitude( lat );
- // result.set_Altitude( alt );
- // result.set_Geocentric_Position( lon_geoc, lat_geoc, radius );
-
- return result;
-}
-
-
// Run multiloop iterations of the flight model
-int fgFlightModelUpdate(int model, FGState& f, int multiloop, int jitter) {
+int fgFlightModelUpdate(int model, FGState& f, int multiloop, int time_offset) {
double time_step, start_elev, end_elev;
// printf("Altitude = %.2f\n", FG_Altitude * 0.3048);
- // base_fdm_state = f;
+ // 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();
// 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 );
base_fdm_state.set_Climb_Rate( (end_elev - start_elev) / time_step );
}
- f = extrapolate_fdm( base_fdm_state, jitter );
-
return 1;
}
// $Log$
+// 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.
//
#define _FLIGHT_HXX
+#ifndef __cplusplus
+# error This library requires C++
+#endif
+
+
/* Required get_()
`FGState::get_Longitude ()'
*/
-#include <Flight/Slew/slew.hxx>
-
-
-#ifndef __cplusplus
-# error This library requires C++
-#endif
+#include <Time/timestamp.hxx>
typedef double FG_VECTOR_3[3];
double climb_rate; // in feet per second
inline double get_Climb_Rate() const { return climb_rate; }
inline void set_Climb_Rate(double rate) { climb_rate = rate; }
+
+ FGTimeStamp valid_stamp; // time this record is valid
+ FGTimeStamp next_stamp; // time this record is valid
+ inline FGTimeStamp get_time_stamp() const { return valid_stamp; }
+ inline void stamp_time() { valid_stamp = next_stamp; next_stamp.stamp(); }
+
+ // Extrapolate FDM based on time_offset (in usec)
+ void extrapolate( int time_offset );
+
};
// $Log$
+// Revision 1.11 1999/01/19 17:52:07 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 13:37:33 curt
// Convert fgTIMESTAMP to FGTimeStamp which holds usec instead of ms.
//
projects / flightgear.git / commitdiff