X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=src%2FInstrumentation%2Fheading_indicator_dg.cxx;h=8966c0f3de8292c084bd673f007c63d3f53f2a97;hb=7c8ad455a327276e09687b380fb4147ae90b6c8c;hp=036caf47cb37472882bb3b4d978fc85934e64e14;hpb=d9bfd5a425df1bad7e3c53a64adce871e299a6b9;p=flightgear.git diff --git a/src/Instrumentation/heading_indicator_dg.cxx b/src/Instrumentation/heading_indicator_dg.cxx index 036caf47c..8966c0f3d 100644 --- a/src/Instrumentation/heading_indicator_dg.cxx +++ b/src/Instrumentation/heading_indicator_dg.cxx @@ -6,7 +6,13 @@ // // This file is in the Public Domain and comes with no warranty. +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + #include +#include +#include #include #include #include @@ -16,6 +22,8 @@ #include "heading_indicator_dg.hxx" +/** Macro calculating x^6 (faster than super-slow math/pow). */ +#define POW6(x) (x*x*x*x*x*x) HeadingIndicatorDG::HeadingIndicatorDG ( SGPropertyNode *node ) : name("heading-indicator-dg"), @@ -24,8 +32,8 @@ HeadingIndicatorDG::HeadingIndicatorDG ( SGPropertyNode *node ) : int i; for ( i = 0; i < node->nChildren(); ++i ) { SGPropertyNode *child = node->getChild(i); - string cname = child->getName(); - string cval = child->getStringValue(); + std::string cname = child->getName(); + std::string cval = child->getStringValue(); if ( cname == "name" ) { name = cval; } else if ( cname == "number" ) { @@ -39,10 +47,6 @@ HeadingIndicatorDG::HeadingIndicatorDG ( SGPropertyNode *node ) : } } -HeadingIndicatorDG::HeadingIndicatorDG () -{ -} - HeadingIndicatorDG::~HeadingIndicatorDG () { } @@ -50,26 +54,32 @@ HeadingIndicatorDG::~HeadingIndicatorDG () void HeadingIndicatorDG::init () { - string branch; + std::string branch; branch = "/instrumentation/" + name; _heading_in_node = fgGetNode("/orientation/heading-deg", true); - SGPropertyNode *node = fgGetNode(branch.c_str(), num, true ); - _offset_node = node->getChild("offset-deg", 0, true); - _serviceable_node = node->getChild("serviceable", 0, true); - _error_node = node->getChild("heading-bug-error-deg", 0, true); - _nav1_error_node = node->getChild("nav1-course-error-deg", 0, true); - _heading_out_node = node->getChild("indicated-heading-deg", 0, true); - _last_heading_deg = (_heading_in_node->getDoubleValue() + - _offset_node->getDoubleValue()); + _yaw_rate_node = fgGetNode("/orientation/yaw-rate-degps", true); + _g_node = fgGetNode("/accelerations/pilot-g", true); + + SGPropertyNode *node = fgGetNode(branch.c_str(), num, true ); + _offset_node = node->getChild("offset-deg", 0, true); + _serviceable_node = node->getChild("serviceable", 0, true); + _heading_bug_error_node = node->getChild("heading-bug-error-deg", 0, true); + _error_node = node->getChild("error-deg", 0, true); + _nav1_error_node = node->getChild("nav1-course-error-deg", 0, true); + _heading_out_node = node->getChild("indicated-heading-deg", 0, true); + _align_node = node->getChild("align-deg", 0, true); + _electrical_node = fgGetNode("/systems/electrical/outputs/DG", true); + + reinit(); } void HeadingIndicatorDG::bind () { std::ostringstream temp; - string branch; + std::string branch; temp << num; branch = "/instrumentation/" + name + "[" + temp.str() + "]"; @@ -83,7 +93,7 @@ void HeadingIndicatorDG::unbind () { std::ostringstream temp; - string branch; + std::string branch; temp << num; branch = "/instrumentation/" + name + "[" + temp.str() + "]"; @@ -91,6 +101,20 @@ HeadingIndicatorDG::unbind () fgUntie((branch + "/spin").c_str()); } +void +HeadingIndicatorDG::reinit (void) +{ + // reset errors/drift values + _align_node->setDoubleValue(0.0); + _error_node->setDoubleValue(0.0); + _offset_node->setDoubleValue(0.0); + + _last_heading_deg = _heading_in_node->getDoubleValue(); + _last_indicated_heading_dg = _last_heading_deg; + + _gyro.reinit(); +} + void HeadingIndicatorDG::update (double dt) { @@ -98,39 +122,67 @@ HeadingIndicatorDG::update (double dt) _gyro.set_power_norm(_electrical_node->getDoubleValue()); _gyro.update(dt); + + // read inputs double spin = _gyro.get_spin_norm(); + double heading = _heading_in_node->getDoubleValue(); + double offset = _offset_node->getDoubleValue(); + + // calculate scaling factor + double factor = POW6(spin); + + // calculate time-based precession (scaled by spin factor, since + // there is no precession when the gyro is stuck). + offset -= dt * (0.25 / 60.0) * factor; // 360deg/day + + // indication should get more and more stuck at low gyro spins + if (spin < 0.9) + { + // when gyro spin is low, then any heading change results in + // increasing the offset + double diff = SGMiscd::normalizePeriodic(-180.0, 180.0, _last_heading_deg - heading); + // scaled by 1-factor, so indication is fully stuck at spin==0 (offset compensates + // any heading change) + offset += diff * (1.0-factor); + } + _last_heading_deg = heading; - // No time-based precession for a flux gate compass - // No magvar - double offset = 0; + // normalize offset + offset = SGMiscd::normalizePeriodic(-180.0,180.0,offset); + _offset_node->setDoubleValue(offset); - // TODO: movement-induced error + // No magvar - set the alignment manually + double align = _align_node->getDoubleValue(); - // Next, calculate the indicated heading, - // introducing errors. - double factor = 0.01 / (spin * spin * spin * spin * spin * spin); - double heading = _heading_in_node->getDoubleValue(); + // Movement-induced error + double yaw_rate = _yaw_rate_node->getDoubleValue(); + double error = _error_node->getDoubleValue(); + double g = _g_node->getDoubleValue(); + if ( fabs ( yaw_rate ) > 5 ) { + error += 0.033 * -yaw_rate * dt * factor; + } + + if ( g > 1.5 || g < -0.5){ + error += 0.033 * g * dt * factor; + } + _error_node->setDoubleValue(error); // Now, we have to get the current // heading and the last heading into // the same range. - while ((heading - _last_heading_deg) > 180) - _last_heading_deg += 360; - while ((heading - _last_heading_deg) < -180) - _last_heading_deg -= 360; + while ((heading - _last_indicated_heading_dg) > 180) + _last_indicated_heading_dg += 360; + while ((heading - _last_indicated_heading_dg) < -180) + _last_indicated_heading_dg -= 360; + heading = fgGetLowPass(_last_indicated_heading_dg, heading, dt * 100); + _last_indicated_heading_dg = heading; - heading = fgGetLowPass(_last_heading_deg, heading, dt/factor); - _last_heading_deg = heading; - - heading += offset; - while (heading < 0) - heading += 360; - while (heading > 360) - heading -= 360; + heading += offset + align + error; + heading = SGMiscd::normalizePeriodic(0.0,360.0,heading); _heading_out_node->setDoubleValue(heading); - // calculate the difference between the indicacted heading + // calculate the difference between the indicated heading // and the selected heading for use with an autopilot static SGPropertyNode *bnode = fgGetNode( "/autopilot/settings/heading-bug-deg", false ); @@ -138,7 +190,7 @@ HeadingIndicatorDG::update (double dt) double diff = bnode->getDoubleValue() - heading; if ( diff < -180.0 ) { diff += 360.0; } if ( diff > 180.0 ) { diff -= 360.0; } - _error_node->setDoubleValue( diff ); + _heading_bug_error_node->setDoubleValue( diff ); } // calculate the difference between the indicated heading // and the selected nav1 radial for use with an autopilot @@ -152,4 +204,4 @@ HeadingIndicatorDG::update (double dt) } } -// end of heading_indicator_fg.cxx +// end of heading_indicator_dg.cxx