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- add (damped) aileron/rudder trimming (may be needed for mibs)

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- use an FPS-independent lowpass filter for all damped properties
- cleanup
This commit is contained in:
mfranz 2007-07-27 21:57:55 +00:00
parent 49779e64f0
commit 26af6a3207
2 changed files with 86 additions and 88 deletions
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145
src/FDM/UFO.cxx
View file

@ -35,25 +35,28 @@
#include "UFO.hxx"
const double throttle_damp = 0.2;
const double aileron_damp = 0.05;
const double elevator_damp = 0.05;
const double elevator_trim_damp = 0.05;
const double rudder_damp = 0.4;
FGUFO::FGUFO( double dt )
: Throttle(0.0),
Aileron(0.0),
Elevator(0.0),
Elevator_Trim(0.0),
Rudder(0.0),
FGUFO::FGUFO( double dt ) :
Throttle(new lowpass(fgGetDouble("/controls/damping/throttle", 0.3))),
Aileron(new lowpass(fgGetDouble("/controls/damping/aileron", 0.65))),
Elevator(new lowpass(fgGetDouble("/controls/damping/elevator", 0.65))),
Rudder(new lowpass(fgGetDouble("/controls/damping/rudder", 0.05))),
Aileron_Trim(new lowpass(fgGetDouble("/controls/damping/aileron-trim", 0.65))),
Elevator_Trim(new lowpass(fgGetDouble("/controls/damping/elevator-trim", 0.65))),
Rudder_Trim(new lowpass(fgGetDouble("/controls/damping/rudder-trim", 0.05))),
Speed_Max(fgGetNode("/engines/engine/speed-max-mps", true))
{
// set_delta_t( dt );
}
FGUFO::~FGUFO() {
delete Throttle;
delete Aileron;
delete Elevator;
delete Rudder;
delete Aileron_Trim;
delete Elevator_Trim;
delete Rudder_Trim;
}
@ -71,94 +74,70 @@ void FGUFO::update( double dt ) {
// cout << "FGLaRCsim::update()" << endl;
if (is_suspended())
return;
return;
double time_step = dt;
// read the throttle
double th = globals->get_controls()->get_throttle( 0 );
if ( globals->get_controls()->get_brake_left() > 0.5
|| globals->get_controls()->get_brake_right() > 0.5 )
{
th = -th;
}
Throttle = th * throttle_damp + Throttle * (1 - throttle_damp);
double throttle = globals->get_controls()->get_throttle( 0 );
double brake_left = globals->get_controls()->get_brake_left();
double brake_right = globals->get_controls()->get_brake_right();
// read the state of the control surfaces
Aileron = globals->get_controls()->get_aileron() * aileron_damp
+ Aileron * (1 - aileron_damp);
Elevator = globals->get_controls()->get_elevator() * elevator_damp
+ Elevator * (1 - elevator_damp);
Elevator_Trim = globals->get_controls()->get_elevator_trim()
* elevator_trim_damp
+ Elevator_Trim * (1 - elevator_trim_damp);
Rudder = globals->get_controls()->get_rudder() * rudder_damp
+ Rudder * (1 - rudder_damp);
if (brake_left > 0.5 || brake_right > 0.5)
throttle = -throttle;
// the velocity of the aircraft
double velocity = Throttle * Speed_Max->getDoubleValue(); // meters/sec
throttle = Throttle->filter(dt, throttle);
// read and lowpass-filter the state of the control surfaces
double aileron = Aileron->filter(dt, globals->get_controls()->get_aileron());
double elevator = Elevator->filter(dt, globals->get_controls()->get_elevator());
double rudder = Rudder->filter(dt, globals->get_controls()->get_rudder());
aileron += Aileron_Trim->filter(dt, globals->get_controls()->get_aileron_trim());
elevator += Elevator_Trim->filter(dt, globals->get_controls()->get_elevator_trim());
rudder += Rudder_Trim->filter(dt, globals->get_controls()->get_rudder_trim());
double velocity = throttle * Speed_Max->getDoubleValue(); // meters/sec
double old_pitch = get_Theta();
double pitch_rate = SGD_PI_4; // assume I will be pitching up
double target_pitch = (-Elevator - Elevator_Trim) * SGD_PI_2;
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)
if (old_pitch > target_pitch) // pitching 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)
{
if (pitch_rate > 0.0) { // pitching up
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)
{
} else if (pitch_rate < 0.0) { // pitching down
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;
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)
{
if (roll_rate > 0.0) { // rolling CW
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)
{
} else if (roll_rate < 0.0) { // rolling CCW
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 );
_set_Climb_Rate( -elevator * 10.0 );
double climb = real_climb_rate * time_step;
// the lateral speed of the aircraft
@ -172,19 +151,19 @@ void FGUFO::update( double dt ) {
// angle of turn
double turn_rate = sin(roll) * SGD_PI_4; // radians/sec
double turn = turn_rate * time_step;
double yaw = fabs(Rudder) < .2 ? 0.0 : Rudder / (25 + fabs(speed) * .1);
double yaw = fabs(rudder) < .2 ? 0.0 : rudder / (25 + fabs(speed) * .1);
// update (lon/lat) position
double lat2, lon2, az2;
if ( fabs(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 );
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 );
_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)
@ -199,8 +178,8 @@ void FGUFO::update( double dt ) {
_set_Euler_Angles(roll, pitch, heading);
_set_Euler_Rates(0,0,0);
_set_Geocentric_Position( lat_geoc, get_Longitude(),
sl_radius + get_Altitude() + climb );
_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;
_update_ground_elev_at_pos();
@ -212,3 +191,5 @@ void FGUFO::update( double dt ) {
set_V_east(sin(heading) * velocity * SG_METER_TO_FEET);
set_V_down(-real_climb_rate);
}

29
src/FDM/UFO.hxx
View file

@ -24,16 +24,33 @@
#ifndef _UFO_HXX
#define _UFO_HXX
#include "flight.hxx"
class FGUFO: public FGInterface {
double Throttle;
double Aileron;
double Elevator;
double Elevator_Trim;
double Rudder;
class lowpass {
double _coeff;
double _last;
bool _initialized;
public:
lowpass(double coeff) : _coeff(coeff), _initialized(false) {}
double filter(double dt, double value) {
if (!_initialized) {
_initialized = true;
return _last = value;
}
double c = dt / (_coeff + dt);
return _last = value * c + _last * (1.0 - c);
}
};
lowpass *Throttle;
lowpass *Aileron;
lowpass *Elevator;
lowpass *Rudder;
lowpass *Aileron_Trim;
lowpass *Elevator_Trim;
lowpass *Rudder_Trim;
SGPropertyNode_ptr Speed_Max;
public: