X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=src%2FSystems%2Fstatic.cxx;h=f8dc2add63d97a452610a1ab241029d0789018f6;hb=9c63b7713307eb4db9f6df7959fe83977f561c42;hp=f58d1ce3cd457a675caa914515a2eaef4bf0a4b0;hpb=043128c7c093c99125ba0ece4c0bcc0b697d2a63;p=flightgear.git

diff --git a/src/Systems/static.cxx b/src/Systems/static.cxx
index f58d1ce3c..f8dc2add6 100644
--- a/src/Systems/static.cxx
+++ b/src/Systems/static.cxx
@@ -1,6 +1,7 @@
 // static.cxx - the static air system.
 // Written by David Megginson, started 2002.
 //
+// Last modified by Eric van den Berg, 09 Nov 2013
 // This file is in the Public Domain and comes with no warranty.
 
 #ifdef HAVE_CONFIG_H
@@ -13,14 +14,20 @@
 
 #include <Main/fg_props.hxx>
 #include <Main/util.hxx>
+#include <simgear/constants.h>
+#include <simgear/math/SGMisc.hxx>
+#include <simgear/math/SGLimits.hxx>
+#include <simgear/math/SGMathFwd.hxx>
+#include <simgear/sg_inlines.h>
 
 
 StaticSystem::StaticSystem ( SGPropertyNode *node )
     :
     _name(node->getStringValue("name", "static")),
     _num(node->getIntValue("number", 0)),
-    _tau(node->getDoubleValue("tau", 1))
-
+    _tau(SGMiscd::max(.0,node->getDoubleValue("tau", 1))),
+    _error_factor(node->getDoubleValue("error-factor", 0)),
+    _type(node->getIntValue("type", 0))
 {
 }
 
@@ -37,6 +44,10 @@ StaticSystem::init ()
     _serviceable_node = node->getChild("serviceable", 0, true);
     _pressure_in_node = fgGetNode("/environment/pressure-inhg", true);
     _pressure_out_node = node->getChild("pressure-inhg", 0, true);
+    _beta_node = fgGetNode("/orientation/side-slip-deg", true);
+    _alpha_node = fgGetNode("/orientation/alpha-deg", true);
+    _mach_node = fgGetNode("/velocities/mach", true);
+    SG_CLAMP_RANGE(_error_factor,0.0,1.0);     // making sure the error_factor is between 0 and 1
 
     reinit();
 }
@@ -62,10 +73,40 @@ void
 StaticSystem::update (double dt)
 {
     if (_serviceable_node->getBoolValue()) {
-        double trat = _tau ? dt/_tau : 100;
-        double target = _pressure_in_node->getDoubleValue();
-        double current = _pressure_out_node->getDoubleValue();
-        _pressure_out_node->setDoubleValue(fgGetLowPass(current, target, trat));
+        double p_new = _pressure_in_node->getDoubleValue();                         //current static pressure around aircraft
+        double p = _pressure_out_node->getDoubleValue();                            //last pressure in aircraft static system
+
+        double beta;
+        double alpha;
+        double mach;
+        double trat = _tau ? dt/_tau : SGLimitsd::max();
+
+        double proj_factor = 0;
+        double pt;
+        double qc_part;
+
+        if (_type == 1) {                                       // type 1 = static pressure dependent on side-slip only: static port on the fuselage
+            beta = _beta_node->getDoubleValue() * SGD_DEGREES_TO_RADIANS;
+            proj_factor = sin(beta);
+        }
+
+        if (_type == 2) {                                       // type 2 = static pressure dependent on aoa and side-slip: static port on the pitot tube
+            alpha = _alpha_node->getDoubleValue() * SGD_DEGREES_TO_RADIANS;
+            beta = _beta_node->getDoubleValue() * SGD_DEGREES_TO_RADIANS;
+            proj_factor = sqrt( 1.0 - cos(beta)*cos(beta) * cos(alpha)*cos(alpha) );
+        }
+
+        if ( (_type ==1) || (_type == 2) ) {
+            mach = _mach_node->getDoubleValue();
+            pt = p_new * pow(1 + 0.2 * mach*mach*proj_factor*proj_factor, 3.5 );    //total pressure perpendicular to static port (=perpendicular to body x-axis)
+            qc_part = (pt - p_new) * _error_factor ;                            //part of impact pressure to be added to static pressure (due to sideslip)
+            p_new = p_new + qc_part;
+        }
+
+        _pressure_out_node->setDoubleValue(
+            _tau > .0 ? fgGetLowPass(p, p_new, trat) : p_new
+        );           //setting new pressure in static system
+
     }
 }