// This file is in the Public Domain and comes with no warranty.
// TODO:
-// - tumble
// - better spin-up
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <simgear/compiler.h>
+
+#include <iostream>
+#include <string>
+#include <sstream>
+
+#include <math.h> // fabs()
+
#include "attitude_indicator.hxx"
#include <Main/fg_props.hxx>
+#include <Main/util.hxx>
+using std::string;
-AttitudeIndicator::AttitudeIndicator ()
+AttitudeIndicator::AttitudeIndicator ( SGPropertyNode *node )
+ :
+ _name(node->getStringValue("name", "attitude-indicator")),
+ _num(node->getIntValue("number", 0)),
+ _suction(node->getStringValue("suction", "/systems/vacuum/suction-inhg")),
+ spin_thresh(0.8),
+ max_roll_error(40.0),
+ max_pitch_error(12.0)
{
}
void
AttitudeIndicator::init ()
{
- // TODO: allow index of pump and AI
- // to be configured.
- _serviceable_node =
- fgGetNode("/instrumentation/attitude-indicator/serviceable", true);
- _spin_node = fgGetNode("/instrumentation/attitude-indicator/spin", true);
+ string branch;
+ branch = "/instrumentation/" + _name;
+
+ SGPropertyNode *node = fgGetNode(branch.c_str(), _num, true );
+ SGPropertyNode *n;
+
_pitch_in_node = fgGetNode("/orientation/pitch-deg", true);
_roll_in_node = fgGetNode("/orientation/roll-deg", true);
- _suction_node = fgGetNode("/systems/vacuum[0]/suction-inhg", true);
- _pitch_out_node =
- fgGetNode("/instrumentation/attitude-indicator/indicated-pitch-deg",
- true);
- _roll_out_node =
- fgGetNode("/instrumentation/attitude-indicator/indicated-roll-deg",
- true);
+ _suction_node = fgGetNode(_suction.c_str(), true);
+ SGPropertyNode *cnode = node->getChild("config", 0, true);
+ _tumble_flag_node = cnode->getChild("tumble-flag", 0, true);
+ _caged_node = node->getChild("caged-flag", 0, true);
+ _tumble_node = node->getChild("tumble-norm", 0, true);
+ if( ( n = cnode->getChild("spin-thresh", 0, false ) ) != NULL )
+ spin_thresh = n->getDoubleValue();
+ if( ( n = cnode->getChild("max-roll-error-deg", 0, false ) ) != NULL )
+ max_roll_error = n->getDoubleValue();
+ if( ( n = cnode->getChild("max-pitch-error-deg", 0, false ) ) != NULL )
+ max_pitch_error = n->getDoubleValue();
+ _pitch_int_node = node->getChild("internal-pitch-deg", 0, true);
+ _roll_int_node = node->getChild("internal-roll-deg", 0, true);
+ _pitch_out_node = node->getChild("indicated-pitch-deg", 0, true);
+ _roll_out_node = node->getChild("indicated-roll-deg", 0, true);
+
+ reinit();
+}
+
+void
+AttitudeIndicator::reinit ()
+{
+ _roll_int_node->setDoubleValue(0.0);
+ _pitch_int_node->setDoubleValue(0.0);
+ _gyro.reinit();
}
void
AttitudeIndicator::bind ()
{
+ std::ostringstream temp;
+ string branch;
+ temp << _num;
+ branch = "/instrumentation/" + _name + "[" + temp.str() + "]";
+
+ fgTie((branch + "/serviceable").c_str(),
+ &_gyro, &Gyro::is_serviceable, &Gyro::set_serviceable);
+ fgTie((branch + "/spin").c_str(),
+ &_gyro, &Gyro::get_spin_norm, &Gyro::set_spin_norm);
}
void
AttitudeIndicator::unbind ()
{
+ std::ostringstream temp;
+ string branch;
+ temp << _num;
+ branch = "/instrumentation/" + _name + "[" + temp.str() + "]";
+
+ fgUntie((branch + "/serviceable").c_str());
+ fgUntie((branch + "/spin").c_str());
}
void
AttitudeIndicator::update (double dt)
{
- // First, calculate the bogo-spin from 0 to 1.
- // All numbers are made up.
-
- double spin = _spin_node->getDoubleValue();
- spin -= 0.005 * dt; // spin decays every 0.5% every second.
-
- // spin increases up to 25% every second
- // if suction is available and the gauge
- // is serviceable.
- if (_serviceable_node->getBoolValue()) {
- double suction = _suction_node->getDoubleValue();
- double step = 0.25 * (suction / 5.0) * dt;
- if ((spin + step) <= (suction / 5.0))
- spin += step;
+ // If it's caged, it doesn't indicate
+ if (_caged_node->getBoolValue()) {
+ _roll_int_node->setDoubleValue(0.0);
+ _pitch_int_node->setDoubleValue(0.0);
+ return;
}
- if (spin > 1.0)
- spin = 1.0;
- else if (spin < 0.0)
- spin = 0.0;
- _spin_node->setDoubleValue(spin);
-
- // Next, calculate the indicated roll
- // and pitch, introducing errors.
- double factor = 1.0 - ((1.0 - spin) * (1.0 - spin));
+
+ // Get the spin from the gyro
+ _gyro.set_power_norm(_suction_node->getDoubleValue()/5.0);
+ _gyro.update(dt);
+ double spin = _gyro.get_spin_norm();
+
+ // Calculate the responsiveness
+ double responsiveness = spin * spin * spin * spin * spin * spin;
+
+ // Get the indicated roll and pitch
double roll = _roll_in_node->getDoubleValue();
double pitch = _pitch_in_node->getDoubleValue();
- roll = 35 + (factor * (roll - 35));
- pitch = 15 + (factor * (pitch - 15));
- _roll_out_node->setDoubleValue(roll);
- _pitch_out_node->setDoubleValue(pitch);
+ // Calculate the tumble for the
+ // next pass.
+ if (_tumble_flag_node->getBoolValue()) {
+ double tumble = _tumble_node->getDoubleValue();
+ if (fabs(roll) > 45.0) {
+ double target = (fabs(roll) - 45.0) / 45.0;
+ target *= target; // exponential past +-45 degrees
+ if (roll < 0)
+ target = -target;
+
+ if (fabs(target) > fabs(tumble))
+ tumble = target;
+
+ if (tumble > 1.0)
+ tumble = 1.0;
+ else if (tumble < -1.0)
+ tumble = -1.0;
+ }
+ // Reerect in 5 minutes
+ double step = dt/300.0;
+ if (tumble < -step)
+ tumble += step;
+ else if (tumble > step)
+ tumble -= step;
+
+ roll += tumble * 45;
+ _tumble_node->setDoubleValue(tumble);
+ }
+
+ roll = fgGetLowPass(_roll_int_node->getDoubleValue(), roll,
+ responsiveness);
+ pitch = fgGetLowPass(_pitch_int_node->getDoubleValue(), pitch,
+ responsiveness);
+
+ // Assign the new values
+ _roll_int_node->setDoubleValue(roll);
+ _pitch_int_node->setDoubleValue(pitch);
+
+ // add in a gyro underspin "error" if gyro is spinning too slowly
+ double roll_error;
+ double pitch_error;
+ if ( spin <= spin_thresh ) {
+ double roll_error_factor = (spin_thresh - spin) / spin_thresh;
+ double pitch_error_factor = (spin_thresh - spin) / spin_thresh;
+ roll_error = roll_error_factor * roll_error_factor * max_roll_error;
+ pitch_error = pitch_error_factor * pitch_error_factor * max_pitch_error;
+ } else {
+ roll_error = 0.0;
+ pitch_error = 0.0;
+ }
+
+ _roll_out_node->setDoubleValue(roll + roll_error);
+ _pitch_out_node->setDoubleValue(pitch + pitch_error);
}
// end of attitude_indicator.cxx
projects / flightgear.git / blobdiff