# include <config.h>
#endif
-#if defined( FG_HAVE_NATIVE_SGI_COMPILERS )
-# include <iostream.h>
-#else
-# include <iostream>
-#endif
+#include <simgear/compiler.h>
+
+#include STL_IOSTREAM
#include <simgear/constants.h>
-#include <simgear/math/fg_types.hxx>
+#include <simgear/math/sg_types.hxx>
+#include <simgear/misc/props.hxx>
#include <Aircraft/aircraft.hxx>
-#include <Main/options.hxx>
-#include <Main/bfi.hxx>
-#include <NetworkOLK/features.hxx>
-FG_USING_NAMESPACE(std);
+SG_USING_NAMESPACE(std);
#include "radiostack.hxx"
#include "steam.hxx"
+static bool isTied = false;
+
\f
////////////////////////////////////////////////////////////////////////
// Declare the functions that read the variables
////////////////////////////////////////////////////////////////////////
-// Anything that reads the BFI directly is not implemented at all!
-
-
double FGSteam::the_STATIC_inhg = 29.92;
-double FGSteam::the_ALT_ft = 0.0;
+double FGSteam::the_ALT_ft = 0.0; // Indicated altitude
double FGSteam::get_ALT_ft() { _CatchUp(); return the_ALT_ft; }
-double FGSteam::get_ASI_kias() { return FGBFI::getAirspeed(); }
+double FGSteam::the_ALT_datum_mb = 1013.0;
+double FGSteam::get_ALT_datum_mb() { return the_ALT_datum_mb; }
+
+void FGSteam::set_ALT_datum_mb ( double datum_mb ) {
+ the_ALT_datum_mb = datum_mb;
+}
+
+double FGSteam::get_ASI_kias() { return fgGetDouble("/velocities/airspeed-kt"); }
double FGSteam::the_VSI_case = 29.92;
double FGSteam::the_VSI_fps = 0.0;
////////////////////////////////////////////////////////////////////////
-int FGSteam::_UpdatesPending = 999; /* Forces filter to reset */
+int FGSteam::_UpdatesPending = 1000000; /* Forces filter to reset */
+ // FIXME: no need to use static
+ // functions any longer.
+
void FGSteam::update ( int timesteps )
{
- _UpdatesPending += timesteps;
+ if (!isTied) {
+ isTied = true;
+ fgTie("/steam/airspeed-kt", FGSteam::get_ASI_kias);
+ fgSetArchivable("/steam/airspeed-kt");
+ fgTie("/steam/altitude-ft", FGSteam::get_ALT_ft);
+ fgSetArchivable("/steam/altitude-ft");
+ fgTie("/steam/altimeter-datum-mb",
+ FGSteam::get_ALT_datum_mb, FGSteam::set_ALT_datum_mb,
+ false); /* don't modify the value */
+ fgSetArchivable("/steam/altimeter-datum-mb");
+ fgTie("/steam/turn-rate", FGSteam::get_TC_std);
+ fgSetArchivable("/steam/turn-rate");
+ fgTie("/steam/slip-skid", FGSteam::get_TC_rad);
+ fgSetArchivable("/steam/slip-skid");
+ fgTie("/steam/vertical-speed-fpm", FGSteam::get_VSI_fps);
+ fgSetArchivable("/steam/vertical-speed-fpm");
+ fgTie("/steam/gyro-compass-deg", FGSteam::get_DG_deg);
+ fgSetArchivable("/steam/gyro-compass-deg");
+ fgTie("/steam/adf-deg", FGSteam::get_HackADF_deg);
+ fgSetArchivable("/steam/adf-deg");
+ fgTie("/steam/gyro-compass-error-deg",
+ FGSteam::get_DG_err, FGSteam::set_DG_err,
+ false); /* don't modify the value */
+ fgSetArchivable("/steam/gyro-compass-error-deg");
+ fgTie("/steam/mag-compass-deg", FGSteam::get_MH_deg);
+ fgSetArchivable("/steam/mag-compass-deg");
+ }
+ _UpdatesPending += timesteps;
}
+/* tc should be (elapsed_time_between_updates / desired_smoothing_time) */
void FGSteam::set_lowpass ( double *outthe, double inthe, double tc )
{
if ( tc < 0.0 )
}
} else
if ( tc < 0.2 )
- { /* Normal mode of operation */
+ { /* Normal mode of operation; fast approximation to exp(-tc) */
(*outthe) = (*outthe) * ( 1.0 - tc )
+ inthe * tc;
} else
}
+#define INHG_TO_MB 33.86388 /* Inches_of_mercury * INHG_TO_MB == millibars. */
+
+// Convert air pressure to altitude by ICAO Standard Atmosphere
+double pressInHgToAltFt(double p_inhg)
+{
+ // Ref. Aviation Formulary, Ed Williams, www.best.com/~williams/avform.htm
+ const double P_0 = 29.92126; // Std. MSL pressure, inHg. (=1013.25 mb)
+ const double p_Tr = 0.2233609 * P_0; // Pressure at tropopause, same units.
+ const double h_Tr = 36089.24; // Alt of tropopause, ft. (=11.0 km)
+
+ if (p_inhg > p_Tr) // 0.0 to 11.0 km
+ return (1.0 - pow((p_inhg / P_0), 1.0 / 5.2558797)) / 6.8755856e-6;
+ return h_Tr + log10(p_inhg / p_Tr) / -4.806346e-5; // 11.0 to 20.0 km
+ // We could put more code for higher altitudes here.
+}
+
+
+// Convert altitude to air pressure by ICAO Standard Atmosphere
+double altFtToPressInHg(double alt_ft)
+{
+ // Ref. Aviation Formulary, Ed Williams, www.best.com/~williams/avform.htm
+ const double P_0 = 29.92126; // Std. MSL pressure, inHg. (=1013.25 mb)
+ const double p_Tr = 0.2233609 * P_0; // Pressure at tropopause, same units.
+ const double h_Tr = 36089.24; // Alt of tropopause, ft. (=11.0 km)
+
+ if (alt_ft < h_Tr) // 0.0 to 11.0 km
+ return P_0 * pow(1.0 - 6.8755856e-6 * alt_ft, 5.2558797);
+ return p_Tr * exp(-4.806346e-5 * (alt_ft - h_Tr)); // 11.0 to 20.0 km
+ // We could put more code for higher altitudes here.
+}
+
+
\f
////////////////////////////////////////////////////////////////////////
// Here the fun really begins
void FGSteam::_CatchUp()
{ if ( _UpdatesPending != 0 )
- { double dt = _UpdatesPending * 1.0 / current_options.get_model_hz();
+ { double dt = _UpdatesPending * 1.0 /
+ fgGetInt("/sim/model-hz"); // FIXME: inefficient
double AccN, AccE, AccU;
- int i /*,j*/;
+ /* int i, j; */
double d, the_ENGINE_rpm;
#if 0
just to be on the safe side. Doing it more than once will
waste CPU time but doesn't hurt anything really.
*/
- if ( _UpdatesPending == 999 )
+ if ( _UpdatesPending > 999999 )
{ FGFeature::register_int ( "Avionics/NAV1/Localizer", &NAV1_LOC );
FGFeature::register_double ( "Avionics/NAV1/Latitude", &NAV1_Lat );
FGFeature::register_double ( "Avionics/NAV1/Longitude", &NAV1_Lon );
More subtle flaw is having it not move or a travel limit
occasionally due to some dirt in the tube or on the ball.
*/
- // the_TC_rad = - ( FGBFI::getSideSlip () ); /* incorrect */
d = - current_aircraft.fdm_state->get_A_Z_pilot();
if ( d < 1 ) d = 1;
set_lowpass ( & the_TC_rad,
*/
set_lowpass ( & the_TC_std,
current_aircraft.fdm_state->get_Phi_dot ()
- * RAD_TO_DEG / 20.0 +
+ * SGD_RADIANS_TO_DEGREES / 20.0 +
current_aircraft.fdm_state->get_Psi_dot ()
- * RAD_TO_DEG / 3.0 , dt );
+ * SGD_RADIANS_TO_DEGREES / 3.0 , dt );
/**************************
We want to know the pilot accelerations,
AccE = current_aircraft.fdm_state->get_V_dot_east();
AccU = current_aircraft.fdm_state->get_V_dot_down()
- 9.81 / 0.3;
- if ( fabs(the_TC_rad) > 0.2 )
+ if ( fabs(the_TC_rad) > 0.2 /* 2.0 */ )
{ /* Massive sideslip jams it; it stops turning */
the_MH_degps = 0.0;
- the_MH_err = FGBFI::getHeading () - the_MH_deg;
+ the_MH_err = fgGetDouble("/orientation/heading-deg") - the_MH_deg;
} else
{ double MagDip, MagVar, CosDip;
double FrcN, FrcE, FrcU, AccTot;
double EdgN, EdgE, EdgU;
double TrqN, TrqE, TrqU, Torque;
/* Find a force vector towards exact magnetic north */
- MagVar = FGBFI::getMagVar() / RAD_TO_DEG;
- MagDip = FGBFI::getMagDip() / RAD_TO_DEG;
+ MagVar = fgGetDouble("/environment/magnetic-variation-deg")
+ / SGD_RADIANS_TO_DEGREES;
+ MagDip = fgGetDouble("/environment/magnetic-dip-deg")
+ / SGD_RADIANS_TO_DEGREES;
CosDip = cos ( MagDip );
FrcN = CosDip * cos ( MagVar );
FrcE = CosDip * sin ( MagVar );
if ( AccTot > 1.0 ) AccTot = sqrt ( AccTot );
else AccTot = 1.0;
/* Force applies to north marking on compass card */
- EdgN = cos ( the_MH_err / RAD_TO_DEG );
- EdgE = sin ( the_MH_err / RAD_TO_DEG );
+ EdgN = cos ( the_MH_err / SGD_RADIANS_TO_DEGREES );
+ EdgE = sin ( the_MH_err / SGD_RADIANS_TO_DEGREES );
EdgU = 0.0;
/* Apply the force to the edge to get torques */
TrqN = EdgE * FrcU - EdgU * FrcE;
}
if ( the_MH_err > 180.0 ) the_MH_err -= 360.0; else
if ( the_MH_err < -180.0 ) the_MH_err += 360.0;
- the_MH_deg = FGBFI::getHeading () - the_MH_err;
+ the_MH_deg = fgGetDouble("/orientation/heading-deg") - the_MH_err;
}
/**************************
scaling capability for the vacuum pump later on.
When we have a real engine model, we can ask it.
*/
- the_ENGINE_rpm = FGBFI::getThrottle() * 26.0;
-
- /**************************
- This is just temporary, until the static source works,
- so we just filter the actual value by one second to
- account for the line impedance of the plumbing.
- */
- set_lowpass ( & the_ALT_ft, FGBFI::getAltitude(), dt );
+ the_ENGINE_rpm = globals->get_controls()->get_throttle(0) * 26.0;
/**************************
First, we need to know what the static line is reporting,
which is a whole simulation area in itself. For now, we cheat.
+ We filter the actual value by one second to
+ account for the line impedance of the plumbing.
*/
- the_STATIC_inhg = 29.92;
- i = (int) the_ALT_ft;
- while ( i > 9000 )
- { the_STATIC_inhg *= 0.707;
- i -= 9000;
- }
- the_STATIC_inhg *= ( 1.0 - 0.293 * i / 9000.0 );
+ double static_inhg
+ = altFtToPressInHg(fgGetDouble("/position/altitude-ft"));
+ set_lowpass ( & the_STATIC_inhg, static_inhg, dt );
/*
NO alternate static source error (student feature),
NO slip-induced error, important for C172 for example.
*/
+ /**************************
+ Altimeter.
+ ICAO standard atmosphere MSL pressure is 1013.25 mb, and pressure
+ gradient is about 28 ft per mb at MSL increasing to about 32 at
+ 5000 and 38 at 10000 ft.
+ Standard altimeters apply the subscale offset to the output altitude,
+ not to the input pressure; I don't know exactly what pressure gradient
+ they assume for this. I choose to make it accurate at low altitudes.
+ Remember, we are trying to simulate a real altimeter, not an ideal one.
+ */
+ set_lowpass ( & the_ALT_ft,
+ pressInHgToAltFt(the_STATIC_inhg) +
+ (the_ALT_datum_mb - 1013.25) * 28.0, /* accurate at low alt. */
+ dt * 10 ); /* smoothing time 0.1 s */
+
/**************************
The VSI case is a low-pass filter of the static line pressure.
The instrument reports the difference, scaled to approx ft.
> have it tumble when you exceed the usual pitch or bank limits,
> put in those insidious turning errors ... for now anyway.
*/
- // cout << "Updates pending = " << _UpdatesPending << endl;
- if ( _UpdatesPending > 999 ) {
- the_DG_err = FGBFI::getMagVar();
- }
- the_DG_degps = 0.0; /* HACK! */
+ if ( _UpdatesPending > 999999 )
+ the_DG_err = fgGetDouble("/environment/magnetic-variation-deg");
+ the_DG_degps = 0.01; /* HACK! */
if (dt<1.0) the_DG_err += dt * the_DG_degps;
- the_DG_deg = FGBFI::getHeading () - the_DG_err;
+ the_DG_deg = fgGetDouble("/orientation/heading-deg") - the_DG_err;
/**************************
Finished updates, now clear the timer
////////////////////////////////////////////////////////////////////////
+#if 0
+
double FGSteam::get_HackGS_deg () {
if ( current_radiostack->get_nav1_inrange() &&
current_radiostack->get_nav1_has_gs() )
{
double x = current_radiostack->get_nav1_gs_dist();
- double y = (FGBFI::getAltitude() - current_radiostack->get_nav1_elev())
- * FEET_TO_METER;
- double angle = atan2( y, x ) * RAD_TO_DEG;
+ double y = (fgGetDouble("/position/altitude-ft")
+ - current_radiostack->get_nav1_elev())
+ * SG_FEET_TO_METER;
+ double angle = atan2( y, x ) * SGD_RADIANS_TO_DEGREES;
return (current_radiostack->get_nav1_target_gs() - angle) * 5.0;
} else {
return 0.0;
double r;
if ( current_radiostack->get_nav1_inrange() ) {
- if ( current_radiostack->get_nav1_loc() ) {
- // localizer doesn't need magvar offset
- r = current_radiostack->get_nav1_heading()
- - current_radiostack->get_nav1_radial();
- } else {
- r = current_radiostack->get_nav1_heading() - FGBFI::getMagVar()
- - current_radiostack->get_nav1_radial();
- }
+ r = current_radiostack->get_nav1_heading()
+ - current_radiostack->get_nav1_radial();
// cout << "Radial = " << current_radiostack->get_nav1_radial()
// << " Bearing = " << current_radiostack->get_nav1_heading()
// << endl;
double r;
if ( current_radiostack->get_nav2_inrange() ) {
- if ( current_radiostack->get_nav2_loc() ) {
- // localizer doesn't need magvar offset
- r = current_radiostack->get_nav2_heading()
- - current_radiostack->get_nav2_radial();
- } else {
- r = current_radiostack->get_nav2_heading() - FGBFI::getMagVar()
- - current_radiostack->get_nav2_radial();
- }
+ r = current_radiostack->get_nav2_heading()
+ - current_radiostack->get_nav2_radial();
// cout << "Radial = " << current_radiostack->get_nav1_radial()
// << " Bearing = " << current_radiostack->get_nav1_heading() << endl;
return r;
}
+#endif
double FGSteam::get_HackOBS1_deg () {
double FGSteam::get_HackADF_deg () {
- double r;
+ static double last_r = 0;
if ( current_radiostack->get_adf_inrange() ) {
- r = current_radiostack->get_adf_heading() - FGBFI::getHeading();
-
+ double r = current_radiostack->get_adf_heading()
+ - fgGetDouble("/orientation/heading-deg");
+ last_r = r;
// cout << "Radial = " << current_radiostack->get_adf_heading()
// << " Heading = " << FGBFI::getHeading() << endl;
+ return r;
} else {
- r = 0.0;
+ return last_r;
}
-
- return r;
}
projects / flightgear.git / blobdiff