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John Denker: move branch cut and apply clamps

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fixed un-normalized outputs
This commit is contained in:
ThorstenB 2011-02-16 19:53:10 +01:00
parent 214919da20
commit 3c3f3a096e
2 changed files with 27 additions and 8 deletions
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33
src/Instrumentation/navradio.cxx
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@ -608,9 +608,21 @@ void FGNavRadio::updateGlideSlope(double dt, const SGVec3d& aircraft, double sig
SGVec3d pos = aircraft - _gsCart; // relative vector from gs antenna to aircraft
// The positive GS axis points along the runway in the landing direction,
// toward the far end, not toward the approach area, so we need a - sign here:
double dot_h = -dot(pos, _gsAxis);
double dot_v = dot(pos, _gsVertical);
_gsDirect = atan2(dot_v, dot_h) * SGD_RADIANS_TO_DEGREES;
double comp_h = -dot(pos, _gsAxis); // component in horiz direction
double comp_v = dot(pos, _gsVertical); // component in vertical direction
//double comp_b = dot(pos, _gsBaseline); // component in baseline direction
//if (comp_b) {} // ... (useful for debugging)
// _gsDirect represents the angle of elevation of the aircraft
// as seen by the GS transmitter.
_gsDirect = atan2(comp_v, comp_h) * SGD_RADIANS_TO_DEGREES;
// At this point, if the aircraft is centered on the glide slope,
// _gsDirect will be a small positive number, e.g. 3.0 degrees
// Aim the branch cut straight down
// into the ground below the GS transmitter:
if (_gsDirect < -90.0) _gsDirect += 360.0;
double deflectionAngle = target_gs - _gsDirect;
if (falseCoursesEnabledNode->getBoolValue()) {
@ -631,10 +643,17 @@ void FGNavRadio::updateGlideSlope(double dt, const SGVec3d& aircraft, double sig
}
}
// GS is documented to be 1.4 degrees thick,
// i.e. plus or minus 0.7 degrees from the midline:
SG_CLAMP_RANGE(deflectionAngle, -0.7, 0.7);
// Many older instrument xml frontends depend on
// the un-normalized gs-needle-deflection.
// Apparently the interface standard is plus or minus 3.5 "volts"
// for a full-scale deflection:
_gsNeedleDeflection = deflectionAngle * 5.0;
_gsNeedleDeflection *= signal_quality_norm;
SG_CLAMP_RANGE(deflectionAngle, -0.7, 0.7);
_gsNeedleDeflectionNorm = (deflectionAngle / 0.7) * signal_quality_norm;
//////////////////////////////////////////////////////////
@ -957,9 +976,9 @@ void FGNavRadio::search()
_gsAxis = tangentVector(_gs->geod(), gs_radial);
// GS baseline unit tangent vector
// (perpendicular to the runay along the ground)
SGVec3d baseline = tangentVector(_gs->geod(), gs_radial + 90.0);
_gsVertical = cross(baseline, _gsAxis);
// (transverse to the runay along the ground)
_gsBaseline = tangentVector(_gs->geod(), gs_radial + 90.0);
_gsVertical = cross(_gsBaseline, _gsAxis);
} // of have glideslope
} // of found LOC or ILS

2
src/Instrumentation/navradio.hxx
View file

@ -153,7 +153,7 @@ class FGNavRadio : public SGSubsystem, public SGPropertyChangeListener
// internal periodic station search timer
double _time_before_search_sec;
SGVec3d _gsCart, _gsAxis, _gsVertical;
SGVec3d _gsCart, _gsAxis, _gsVertical, _gsBaseline;
FGNavRecordPtr _dme;
bool _dmeInRange;