56 lines
1.8 KiB
C++
56 lines
1.8 KiB
C++
// vertical_speed_indicator.cxx - a regular VSI.
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// Written by David Megginson, started 2002.
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//
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// This file is in the Public Domain and comes with no warranty.
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#include <simgear/math/interpolater.hxx>
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#include "vertical_speed_indicator.hxx"
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#include <Main/fg_props.hxx>
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#include <Main/util.hxx>
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VerticalSpeedIndicator::VerticalSpeedIndicator ( SGPropertyNode *node )
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: _internal_pressure_inhg(29.92),
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_name(node->getStringValue("name", "vertical-speed-indicator")),
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_num(node->getIntValue("number", 0)),
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_static_pressure(node->getStringValue("static-pressure", "/systems/static/pressure-inhg"))
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{
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}
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VerticalSpeedIndicator::~VerticalSpeedIndicator ()
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{
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}
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void
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VerticalSpeedIndicator::init ()
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{
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string branch;
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branch = "/instrumentation/" + _name;
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SGPropertyNode *node = fgGetNode(branch.c_str(), _num, true );
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_serviceable_node = node->getChild("serviceable", 0, true);
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_pressure_node = fgGetNode(_static_pressure.c_str(), true);
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_speed_node = node->getChild("indicated-speed-fpm", 0, true);
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// Initialize at ambient pressure
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_internal_pressure_inhg = _pressure_node->getDoubleValue();
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}
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void
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VerticalSpeedIndicator::update (double dt)
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{
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// model taken from steam.cxx, with change
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// from 10000 to 10500 for manual factor
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if (_serviceable_node->getBoolValue()) {
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double pressure = _pressure_node->getDoubleValue();
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_speed_node
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->setDoubleValue((_internal_pressure_inhg - pressure) * 10500);
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_internal_pressure_inhg =
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fgGetLowPass(_internal_pressure_inhg,
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_pressure_node->getDoubleValue(),
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dt/6.0);
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}
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}
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// end of vertical_speed_indicator.cxx
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