# include <config.h>
#endif
-#include <plib/sg.h>
+#include <simgear/sg_inlines.h>
#include "mag_compass.hxx"
#include <Main/fg_props.hxx>
MagCompass::MagCompass ( SGPropertyNode *node )
: _error_deg(0.0),
_rate_degps(0.0),
- name("magnetic-compass"),
- num(0)
-{
- int i;
- for ( i = 0; i < node->nChildren(); ++i ) {
- SGPropertyNode *child = node->getChild(i);
- string cname = child->getName();
- string cval = child->getStringValue();
- if ( cname == "name" ) {
- name = cval;
- } else if ( cname == "number" ) {
- num = child->getIntValue();
- } else {
- SG_LOG( SG_INSTR, SG_WARN, "Error in magnetic-compass config logic" );
- if ( name.length() ) {
- SG_LOG( SG_INSTR, SG_WARN, "Section = " << name );
- }
- }
- }
-}
-
-MagCompass::MagCompass ()
- : _error_deg(0.0),
- _rate_degps(0.0)
+ _name(node->getStringValue("name", "magnetic-compass")),
+ _num(node->getIntValue("number", 0))
{
}
MagCompass::init ()
{
string branch;
- branch = "/instrumentation/" + name;
+ branch = "/instrumentation/" + _name;
- SGPropertyNode *node = fgGetNode(branch.c_str(), num, true );
+ SGPropertyNode *node = fgGetNode(branch.c_str(), _num, true );
_serviceable_node = node->getChild("serviceable", 0, true);
- _roll_node =
- fgGetNode("/orientation/roll-deg", true);
- _pitch_node =
- fgGetNode("/orientation/pitch-deg", true);
- _heading_node =
- fgGetNode("/orientation/heading-magnetic-deg", true);
- _beta_node =
- fgGetNode("/orientation/side-slip-deg", true);
- _dip_node =
- fgGetNode("/environment/magnetic-dip-deg", true);
- _x_accel_node =
- fgGetNode("/accelerations/pilot/x-accel-fps_sec", true);
- _y_accel_node =
- fgGetNode("/accelerations/pilot/y-accel-fps_sec", true);
- _z_accel_node =
- fgGetNode("/accelerations/pilot/z-accel-fps_sec", true);
+ _roll_node = fgGetNode("/orientation/roll-deg", true);
+ _pitch_node = fgGetNode("/orientation/pitch-deg", true);
+ _heading_node = fgGetNode("/orientation/heading-magnetic-deg", true);
+ _beta_node = fgGetNode("/orientation/side-slip-deg", true);
+ _dip_node = fgGetNode("/environment/magnetic-dip-deg", true);
+ _x_accel_node = fgGetNode("/accelerations/pilot/x-accel-fps_sec", true);
+ _y_accel_node = fgGetNode("/accelerations/pilot/y-accel-fps_sec", true);
+ _z_accel_node = fgGetNode("/accelerations/pilot/z-accel-fps_sec", true);
_out_node = node->getChild("indicated-heading-deg", 0, true);
-
- _serviceable_node->setBoolValue(true);
}
MagCompass::update (double delta_time_sec)
{
// This is the real magnetic
- // heading, which will almost
- // never appear.
- double heading_mag_deg = _heading_node->getDoubleValue();
+ // which would be displayed
+ // if the compass had no errors.
+ //double heading_mag_deg = _heading_node->getDoubleValue();
- // don't update if it's broken
+ // don't update if the compass
+ // is broken
if (!_serviceable_node->getBoolValue())
return;
/*
- Jam on an excessive sideslip.
- */
+ * Vassilii: commented out because this way, even when parked,
+ * w/o any accelerations and level, the compass is jammed.
+ * If somebody wants to model jamming, real forces (i.e. accelerations)
+ * and not sideslip angle must be considered.
+ */
+#if 0
+ // jam on excessive sideslip
if (fabs(_beta_node->getDoubleValue()) > 12.0) {
_rate_degps = 0.0;
return;
}
+#endif
/*
Hc = atan2(sin(Hm)cos(theta)-tan(mu)sin(theta), cos(Hm))
- This function changes the variable names to the more common
- psi for the heading, theta for the pitch, and phi for the
- roll. It also modifies the equation to incorporate pitch
- as well as roll, as suggested by Chris Metzler.
+ This function changes the variable names to the more common psi
+ for the heading, theta for the pitch, and phi for the roll (and
+ target_deg for Hc). It also modifies the equation to
+ incorporate pitch as well as roll, as suggested by Chris
+ Metzler.
*/
// bank angle (radians)
*/
double x_accel_g = _x_accel_node->getDoubleValue() / 32;
double y_accel_g = _y_accel_node->getDoubleValue() / 32;
- double z_accel_g = _z_accel_node->getDoubleValue() / 32;
+ //double z_accel_g = _z_accel_node->getDoubleValue() / 32;
theta -= 0.07 * x_accel_g;
phi -= 0.07 * y_accel_g;
////////////////////////////////////////////////////////////////////
- // calculate target compass heading Hc in degrees
+ // calculate target compass heading degrees
////////////////////////////////////////////////////////////////////
// these are expensive: don't repeat
- sin_theta * sin_mu;
// This is the value that the compass
- // is *trying* to display, but it
- // takes time to move there, and because
- // of momentum, the compass will often
- // overshoot.
- double Hc = atan2(a, b) * SGD_RADIANS_TO_DEGREES;
-
- _out_node->setDoubleValue(Hc);
+ // is *trying* to display.
+ double target_deg = atan2(a, b) * SGD_RADIANS_TO_DEGREES;
+ double old_deg = _out_node->getDoubleValue();
+
+ while ((target_deg - old_deg) > 180.0)
+ target_deg -= 360.0;
+ while ((target_deg - old_deg) < -180.0)
+ target_deg += 360.0;
+
+ // The compass has a current rate of
+ // rotation -- move the rate of rotation
+ // towards one that will turn the compass
+ // to the correct heading, but lag a bit.
+ // (so that the compass can keep overshooting
+ // and coming back).
+ double error = target_deg - old_deg;
+ _rate_degps = fgGetLowPass(_rate_degps, error, delta_time_sec / 5.0);
+ double indicated_deg = old_deg + _rate_degps * delta_time_sec;
+ SG_NORMALIZE_RANGE(indicated_deg, 0.0, 360.0);
+
+ // That's it -- set the messed-up heading.
+ _out_node->setDoubleValue(indicated_deg);
}
// end of altimeter.cxx
projects / flightgear.git / blobdiff