--- /dev/null
+// UFO.cxx -- interface to the "UFO" flight model
+//
+// Written by Curtis Olson, started October 1999.
+// Slightly modified from MagicCarpet.cxx by Jonathan Polley, April 2002
+//
+// Copyright (C) 1999-2002 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.
+//
+
+
+#include <simgear/math/sg_geodesy.hxx>
+#include <simgear/math/point3d.hxx>
+#include <simgear/math/polar3d.hxx>
+
+#include <Controls/controls.hxx>
+#include <Main/globals.hxx>
+#include <Main/fg_props.hxx>
+
+#include "UFO.hxx"
+
+
+FGUFO::FGUFO( double dt ) {
+ set_delta_t( dt );
+}
+
+
+FGUFO::~FGUFO() {
+}
+
+
+// Initialize the UFO flight model, dt is the time increment
+// for each subsequent iteration through the EOM
+void FGUFO::init() {
+ common_init();
+}
+
+
+// Run an iteration of the EOM (equations of motion)
+void FGUFO::update( int multiloop ) {
+ // cout << "FGLaRCsim::update()" << endl;
+
+ double time_step = get_delta_t() * multiloop;
+
+ // read the throttle
+ double Throttle = globals->get_controls()->get_throttle( 0 );
+
+ // read the state of the control surfaces
+ double Aileron = globals->get_controls()->get_aileron();
+ double Elevator = globals->get_controls()->get_elevator();
+
+ // the velocity of the aircraft
+ double velocity = Throttle * 2000; // meters/sec
+
+ double old_pitch = get_Theta();
+ double pitch_rate = SGD_PI_4; // assume I will be pitching up
+ double target_pitch = -Elevator * SGD_PI_2;
+
+ // if I am pitching down
+ if (old_pitch > target_pitch)
+ // set the pitch rate to negative (down)
+ pitch_rate *= -1;
+
+ double pitch = old_pitch + (pitch_rate * time_step);
+
+ // if I am pitching up
+ if (pitch_rate > 0.0)
+ {
+ // clip the pitch at the limit
+ if ( pitch > target_pitch)
+ {
+ pitch = target_pitch;
+ }
+ }
+ // if I am pitching down
+ else if (pitch_rate < 0.0)
+ {
+ // clip the pitch at the limit
+ if ( pitch < target_pitch)
+ {
+ pitch = target_pitch;
+ }
+ }
+
+ double old_roll = get_Phi();
+ double roll_rate = SGD_PI_4;
+ double target_roll = Aileron * SGD_PI_2;
+
+ if (old_roll > target_roll)
+ roll_rate *= -1;
+
+ double roll = old_roll + (roll_rate * time_step);
+
+ // if I am rolling CW
+ if (roll_rate > 0.0)
+ {
+ // clip the roll at the limit
+ if ( roll > target_roll)
+ {
+ roll = target_roll;
+ }
+ }
+ // if I am rolling CCW
+ else if (roll_rate < 0.0)
+ {
+ // clip the roll at the limit
+ if ( roll < target_roll)
+ {
+ roll = target_roll;
+ }
+ }
+
+ // the vertical speed of the aircraft
+ double real_climb_rate = sin (pitch) * SG_METER_TO_FEET * velocity; // feet/sec
+ _set_Climb_Rate( -Elevator * 10.0 );
+ double climb = real_climb_rate * time_step;
+
+ // the lateral speed of the aircraft
+ double speed = cos (pitch) * velocity; // meters/sec
+ double dist = speed * time_step;
+ double kts = velocity * SG_METER_TO_NM * 3600.0;
+ _set_V_equiv_kts( kts );
+ _set_V_calibrated_kts( kts );
+ _set_V_ground_speed( kts );
+
+ // angle of turn
+ double turn_rate = sin(roll) * SGD_PI_4; // radians/sec
+ double turn = turn_rate * time_step;
+
+ // update (lon/lat) position
+ double lat2, lon2, az2;
+ if ( speed > SG_EPSILON ) {
+ geo_direct_wgs_84 ( get_Altitude(),
+ get_Latitude() * SGD_RADIANS_TO_DEGREES,
+ get_Longitude() * SGD_RADIANS_TO_DEGREES,
+ get_Psi() * SGD_RADIANS_TO_DEGREES,
+ dist, &lat2, &lon2, &az2 );
+
+ _set_Longitude( lon2 * SGD_DEGREES_TO_RADIANS );
+ _set_Latitude( lat2 * SGD_DEGREES_TO_RADIANS );
+ }
+
+ // cout << "lon error = " << fabs(end.x()*SGD_RADIANS_TO_DEGREES - lon2)
+ // << " lat error = " << fabs(end.y()*SGD_RADIANS_TO_DEGREES - lat2)
+ // << endl;
+
+ double sl_radius, lat_geoc;
+ sgGeodToGeoc( get_Latitude(), get_Altitude(), &sl_radius, &lat_geoc );
+
+ // update euler angles
+ _set_Euler_Angles( roll, pitch,
+ fmod(get_Psi() + turn, SGD_2PI) );
+ _set_Euler_Rates(0,0,0);
+
+ _set_Geocentric_Position( lat_geoc, get_Longitude(),
+ sl_radius + get_Altitude() + climb );
+ // cout << "sea level radius (ft) = " << sl_radius << endl;
+ // cout << "(setto) sea level radius (ft) = " << get_Sea_level_radius() << endl;
+ _set_Sea_level_radius( sl_radius * SG_METER_TO_FEET);
+ _set_Altitude( get_Altitude() + climb );
+}
--- /dev/null
+// UFO.hxx -- interface to the "UFO" flight model
+//
+// Written by Curtis Olson, started October 1999.
+// Slightly modified from MagicCarpet.hxx by Jonathan Polley, April 2002
+//
+// Copyright (C) 1999-2002 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.
+//
+
+
+#ifndef _UFO_HXX
+#define _UFO_HXX
+
+
+#include "flight.hxx"
+
+
+class FGUFO: public FGInterface {
+
+public:
+ FGUFO( double dt );
+ ~FGUFO();
+
+ // reset flight params to a specific position
+ void init();
+
+ // update position based on inputs, positions, velocities, etc.
+ void update( int multiloop );
+
+};
+
+
+#endif // _UFO_HXX
projects / flightgear.git / commitdiff