--- /dev/null
+// gsdi.cxx - Ground Speed Drift Angle Indicator (known as GSDI or GSDA)
+// Written by Melchior FRANZ, started 2006.
+//
+// Copyright (C) 2006 Melchior FRANZ - mfranz#aon:at
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <simgear/sg_inlines.h>
+#include <simgear/constants.h>
+
+#include <Main/fg_props.hxx>
+#include "gsdi.hxx"
+
+
+/*
+ * Failures or inaccuracies are currently not modeled due to lack of data.
+ * The Doppler based GSDI should output unreliable data with increasing
+ * pitch, roll, vertical acceleration and altitude-agl.
+ */
+
+
+GSDI::GSDI(SGPropertyNode *node) :
+ _name("gsdi"),
+ _num(0)
+{
+ for (int i = 0; i < node->nChildren(); ++i) {
+ SGPropertyNode *child = node->getChild(i);
+ string name = child->getName();
+
+ if (name == "name") {
+ _name = child->getStringValue();
+ } else if (name == "number") {
+ _num = child->getIntValue();
+ } else {
+ SG_LOG(SG_INSTR, SG_WARN, "Error in gsdi config logic");
+ if (_name.length())
+ SG_LOG(SG_INSTR, SG_WARN, "Section = " << _name);
+ }
+ }
+}
+
+
+GSDI::GSDI()
+{
+}
+
+
+GSDI::~GSDI()
+{
+}
+
+
+void GSDI::init()
+{
+ string branch;
+ branch = "/instrumentation/" + _name;
+ SGPropertyNode *n = fgGetNode(branch.c_str(), _num, true);
+ _serviceableN = n->getNode("serviceable", true);
+
+ // input
+ _headingN = fgGetNode("/orientation/heading-deg", true);
+ _ubodyN = fgGetNode("/velocities/uBody-fps", true);
+ _vbodyN = fgGetNode("/velocities/vBody-fps", true);
+ _wind_dirN = fgGetNode("/environment/wind-from-heading-deg", true);
+ _wind_speedN = fgGetNode("/environment/wind-speed-kt", true);
+
+ // output
+ _drift_uN = n->getNode("drift-u-kt", true);
+ _drift_vN = n->getNode("drift-v-kt", true);
+ _drift_speedN = n->getNode("drift-speed-kt", true);
+ _drift_angleN = n->getNode("drift-angle-deg", true);
+}
+
+
+void GSDI::update(double /*delta_time_sec*/)
+{
+ if (!_serviceableN->getBoolValue())
+ return;
+
+ double wind_speed = _wind_speedN->getDoubleValue();
+ double rel_wind_dir = (_headingN->getDoubleValue() - _wind_dirN->getDoubleValue())
+ * SGD_DEGREES_TO_RADIANS;
+ double wind_u = wind_speed * cos(rel_wind_dir);
+ double wind_v = wind_speed * sin(rel_wind_dir);
+
+ double u = _ubodyN->getDoubleValue() * SG_FPS_TO_KT - wind_u;
+ double v = _vbodyN->getDoubleValue() * SG_FPS_TO_KT + wind_v;
+
+ double speed = sqrt(u * u + v * v);
+ double angle = atan2(v, u) * SGD_RADIANS_TO_DEGREES;
+
+ _drift_uN->setDoubleValue(u);
+ _drift_vN->setDoubleValue(v);
+ _drift_speedN->setDoubleValue(speed);
+ _drift_angleN->setDoubleValue(angle);
+}
+
+// end of gsdi.cxx
--- /dev/null
+// gsdi.cxx - Ground Speed Drift Angle Indicator (known as GSDI or GSDA)
+// Written by Melchior FRANZ, started 2006.
+//
+// Copyright (C) 2006 Melchior FRANZ - mfranz#aon:at
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+
+#ifndef __INSTRUMENTS_GSDI_HXX
+#define __INSTRUMENTS_GSDI_HXX 1
+
+#include <simgear/props/props.hxx>
+#include <simgear/structure/subsystem_mgr.hxx>
+
+
+/**
+ * Input properties:
+ *
+ * /instrumentation/gsdi/serviceable
+ * /orientation/heading-deg
+ * /velocities/uBody-fps
+ * /velocities/vBody-fps
+ * /environment/wind-from-heading-deg
+ * /environment/wind-speed-kt
+ *
+ * Output properties:
+ *
+ * /instrumentation/gsdi/drift-u-kt
+ * /instrumentation/gsdi/drift-v-kt
+ * /instrumentation/gsdi/drift-speed-kt
+ * /instrumentation/gsdi/drift-angle-deg
+ */
+class GSDI : public SGSubsystem
+{
+public:
+ GSDI(SGPropertyNode *node);
+ GSDI();
+ virtual ~GSDI();
+
+ virtual void init();
+ virtual void update(double dt);
+
+private:
+ string _name;
+ int _num;
+
+ SGPropertyNode_ptr _serviceableN;
+ SGPropertyNode_ptr _headingN;
+ SGPropertyNode_ptr _ubodyN;
+ SGPropertyNode_ptr _vbodyN;
+ SGPropertyNode_ptr _wind_speedN;
+ SGPropertyNode_ptr _wind_dirN;
+ SGPropertyNode_ptr _drift_uN;
+ SGPropertyNode_ptr _drift_vN;
+ SGPropertyNode_ptr _drift_speedN;
+ SGPropertyNode_ptr _drift_angleN;
+};
+
+#endif // _INSTRUMENTS_GSDI_HXX
projects / flightgear.git / commitdiff