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Renamed /velocities/side-slip-rad to /orientation/side-slip-rad.

Renamed /velocities/side-slip-deg to /orientation/side-slip-deg.

Renamed /velocities/alpha-deg to /orientation/alpha-deg.

Added /accelerations/ned/north-accel-fps_sec.

Added /accelerations/ned/east-accel-fps_sec.

Added /accelerations/ned/down-accel-fps_sec.

Renamed /accelerations/pilot/x-accel-ft_sec2 to
/accelerations/pilot/x-accel-fps_sec.

Renamed /accelerations/pilot/y-accel-ft_sec2 to
/accelerations/pilot/y-accel-fps_sec.

Renamed /accelerations/pilot/z-accel-ft_sec2 to
/accelerations/pilot/z-accel-fps_sec.
This commit is contained in:
david 2003-01-26 15:53:35 +00:00
parent fe45f5b7a8
commit acbb9f5aff
3 changed files with 202 additions and 6 deletions

View file

@ -391,21 +391,29 @@ FGInterface::bind ()
fgTie("/velocities/glideslope", this,
&FGInterface::get_Gamma_vert_rad,
&FGInterface::set_Gamma_vert_rad );
fgTie("/velocities/side-slip-rad", this,
fgTie("/orientation/side-slip-rad", this,
&FGInterface::get_Beta); // read-only
fgTie("/velocities/side-slip-deg", this,
fgTie("/orientation/side-slip-deg", this,
&FGInterface::get_Beta_deg); // read-only
fgTie("/velocities/alpha-deg", this,
fgTie("/orientation/alpha-deg", this,
&FGInterface::get_Alpha_deg); // read-only
fgTie("/accelerations/nlf", this,
&FGInterface::get_Nlf); // read-only
// NED accelerations
fgTie("/accelerations/ned/north-accel-fps_sec",
this, &FGInterface::get_V_dot_north);
fgTie("/accelerations/ned/east-accel-fps_sec",
this, &FGInterface::get_V_dot_east);
fgTie("/accelerations/ned/down-accel-fps_sec",
this, &FGInterface::get_V_dot_down);
// Pilot accelerations
fgTie("/accelerations/pilot/x-accel-ft_sec2",
fgTie("/accelerations/pilot/x-accel-fps_sec",
this, &FGInterface::get_A_X_pilot);
fgTie("/accelerations/pilot/y-accel-ft_sec2",
fgTie("/accelerations/pilot/y-accel-fps_sec",
this, &FGInterface::get_A_Y_pilot);
fgTie("/accelerations/pilot/z-accel-ft_sec2",
fgTie("/accelerations/pilot/z-accel-fps_sec",
this, &FGInterface::get_A_Z_pilot);
}

View file

@ -0,0 +1,122 @@
// mag_compass.cxx - a magnetic compass.
// Written by David Megginson, started 2003.
//
// This file is in the Public Domain and comes with no warranty.
// This implementation is derived from an earlier one by Alex Perry,
// which appeared in src/Cockpit/steam.cxx
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <plib/sg.h>
#include "mag_compass.hxx"
#include <Main/fg_props.hxx>
#include <Main/util.hxx>
MagCompass::MagCompass ()
: _error_deg(0.0),
_rate_degps(0.0)
{
}
MagCompass::~MagCompass ()
{
}
void
MagCompass::init ()
{
_serviceable_node =
fgGetNode("/instrumentation/magnetic-compass/serviceable", true);
_heading_node =
fgGetNode("/orientation/heading-deg", true);
_beta_node =
fgGetNode("/orientation/side-slip-deg", true);
_variation_node =
fgGetNode("/environment/magnetic-variation-deg", true);
_dip_node =
fgGetNode("/environment/magnetic-dip-deg", true);
_north_accel_node =
fgGetNode("/accelerations/ned/north-accel-fps_sec", true);
_east_accel_node =
fgGetNode("/accelerations/ned/east-accel-fps_sec", true);
_down_accel_node =
fgGetNode("/accelerations/ned/down-accel-fps_sec", true);
_out_node =
fgGetNode("/instrumentation/magnetic-compass/indicated-heading-deg",
true);
}
void
MagCompass::update (double delta_time_sec)
{
// algorithm from Alex Perry
// possibly broken by David Megginson
// don't update if it's broken
if (!_serviceable_node->getBoolValue())
return;
// jam on a sideslip of 12 degrees or more
if (fabs(_beta_node->getDoubleValue()) > 12.0) {
_rate_degps = 0.0;
_error_deg = _heading_node->getDoubleValue() -
_out_node->getDoubleValue();
return;
}
double accelN = _north_accel_node->getDoubleValue();
double accelE = _east_accel_node->getDoubleValue();
double accelU = _down_accel_node->getDoubleValue() - 32.0; // why?
// force vector towards magnetic north pole
double var = _variation_node->getDoubleValue() * SGD_DEGREES_TO_RADIANS;
double dip = _dip_node->getDoubleValue() * SGD_DEGREES_TO_RADIANS;
double cosdip = cos(dip);
double forceN = cosdip * cos(var);
double forceE = cosdip * sin(var);
double forceU = sin(dip);
// rotation is around acceleration axis
// (magnitude doesn't matter)
double accel = accelN * accelN + accelE * accelE + accelU * accelU;
if (accel > 1.0)
accel = sqrt(accel);
else
accel = 1.0;
// North marking on compass card
double edgeN = cos(_error_deg * SGD_DEGREES_TO_RADIANS);
double edgeE = sin(_error_deg * SGD_DEGREES_TO_RADIANS);
double edgeU = 0.0;
// apply the force to that edge to get torques
double torqueN = edgeE * forceU - edgeU * forceE;
double torqueE = edgeU * forceN - edgeN * forceU;
double torqueU = edgeN * forceE - edgeE * forceN;
// get the component parallel to the axis
double torque = (torqueN * accelN +
torqueE * accelE +
torqueU * accelU) * 5.0 / accel;
// the compass has angular momentum,
// so apply a torque and wait
if (delta_time_sec < 1.0) {
_rate_degps = _rate_degps * (1.0 - delta_time_sec) - torque;
_error_deg += delta_time_sec * _rate_degps;
}
if (_error_deg > 180.0)
_error_deg -= 360.0;
else if (_error_deg < -180.0)
_error_deg += 360.0;
// Set the indicated heading
_out_node->setDoubleValue(_heading_node->getDoubleValue() - _error_deg);
}
// end of altimeter.cxx

View file

@ -0,0 +1,66 @@
// mag_compass.hxx - an altimeter tied to the static port.
// Written by David Megginson, started 2002.
//
// This file is in the Public Domain and comes with no warranty.
#ifndef __INSTRUMENTS_MAG_COMPASS_HXX
#define __INSTRUMENTS_MAG_COMPASS_HXX 1
#ifndef __cplusplus
# error This library requires C++
#endif
#include <simgear/misc/props.hxx>
#include <Main/fgfs.hxx>
/**
* Model a magnetic compass.
*
* Input properties:
*
* /instrumentation/magnetic-compass/serviceable
* /orientation/heading-deg
* /orientation/beta-deg
* /environment/magnetic-variation-deg
* /environment/magnetic-dip-deg
* /accelerations/ned/north-accel-fps_sec
* /accelerations/ned/east-accel-fps_sec
* /accelerations/ned/down-accel-fps_sec
*
* Output properties:
*
* /instrumentation/magnetic-compass/indicated-heading-deg
*/
class MagCompass : public FGSubsystem
{
public:
MagCompass ();
virtual ~MagCompass ();
virtual void init ();
virtual void update (double dt);
private:
double _error_deg;
double _rate_degps;
SGPropertyNode_ptr _serviceable_node;
SGPropertyNode_ptr _heading_node;
SGPropertyNode_ptr _beta_node;
SGPropertyNode_ptr _variation_node;
SGPropertyNode_ptr _dip_node;
SGPropertyNode_ptr _y_accel_node;
SGPropertyNode_ptr _z_accel_node;
SGPropertyNode_ptr _north_accel_node;
SGPropertyNode_ptr _east_accel_node;
SGPropertyNode_ptr _down_accel_node;
SGPropertyNode_ptr _out_node;
};
#endif // __INSTRUMENTS_MAG_COMPASS_HXX