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flightgear/src/Instrumentation/attitude_indicator.cxx
2003-01-26 20:20:15 +00:00

74 lines
2.1 KiB
C++

// attitude_indicator.cxx - a vacuum-powered attitude indicator.
// Written by David Megginson, started 2002.
//
// This file is in the Public Domain and comes with no warranty.
// TODO:
// - tumble
// - better spin-up
#include "attitude_indicator.hxx"
#include <Main/fg_props.hxx>
AttitudeIndicator::AttitudeIndicator ()
{
}
AttitudeIndicator::~AttitudeIndicator ()
{
}
void
AttitudeIndicator::init ()
{
// TODO: allow index of pump and AI
// to be configured.
_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);
}
void
AttitudeIndicator::bind ()
{
fgTie("/instrumentation/attitude-indicator/serviceable",
&_gyro, &Gyro::is_serviceable, &Gyro::set_serviceable);
fgTie("/instrumentation/attitude-indicator/spin",
&_gyro, &Gyro::get_spin_norm, &Gyro::set_spin_norm);
}
void
AttitudeIndicator::unbind ()
{
fgUntie("/instrumentation/attitude-indicator/serviceable");
fgUntie("/instrumentation/attitude-indicator/spin");
}
void
AttitudeIndicator::update (double dt)
{
// Get the spin from the gyro
_gyro.set_power_norm(_suction_node->getDoubleValue()/5.0);
_gyro.update(dt);
double spin = _gyro.get_spin_norm();
// Next, calculate the indicated roll
// and pitch, introducing errors.
double factor = 1.0 - ((1.0 - spin) * (1.0 - spin) * (1.0 - spin));
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);
}
// end of attitude_indicator.cxx