// cout << "_model = " << _model << endl;
if ( _model == "battery" ) {
model = FG_BATTERY;
+ amp_hours = node->getFloatValue("amp-hours", 40.0);
+ percent_remaining = node->getFloatValue("percent-remaining", 1.0);
+ charge_amps = node->getFloatValue("charge-amps", 7.0);
} else if ( _model == "alternator" ) {
model = FG_ALTERNATOR;
+ rpm_src = node->getStringValue("rpm-source");
+ rpm_threshold = node->getFloatValue("rpm-threshold", 600.0);
+ ideal_amps = node->getFloatValue("amps", 60.0);
} else if ( _model == "external" ) {
model = FG_EXTERNAL;
+ ideal_amps = node->getFloatValue("amps", 60.0);
} else {
model = FG_UNKNOWN;
}
- volts = node->getDoubleValue("volts");
- amps = node->getDoubleValue("amps");
- rpm_src = node->getStringValue("rpm-source");
+ ideal_volts = node->getFloatValue("volts");
int i;
for ( i = 0; i < node->nChildren(); ++i ) {
string prop = child->getStringValue();
// cout << " Adding prop = " << prop << endl;
add_prop( prop );
- fgSetDouble( prop.c_str(), amps );
+ fgSetFloat( prop.c_str(), ideal_amps );
}
}
}
-double FGElectricalSupplier::get_output() {
+float FGElectricalSupplier::apply_load( float amps, float dt ) {
+ if ( model == FG_BATTERY ) {
+ // calculate amp hours used
+ float amphrs_used = amps * dt / 3600.0;
+
+ // calculate percent of total available capacity
+ float percent_used = amphrs_used / amp_hours;
+ percent_remaining -= percent_used;
+ if ( percent_remaining < 0.0 ) {
+ percent_remaining = 0.0;
+ } else if ( percent_remaining > 1.0 ) {
+ percent_remaining = 1.0;
+ }
+ // cout << "battery percent = " << percent_remaining << endl;
+ return amp_hours * percent_remaining;
+ } else if ( model == FG_ALTERNATOR ) {
+ // scale alternator output for rpms < 600. For rpms >= 600
+ // give full output. This is just a WAG, and probably not how
+ // it really works but I'm keeping things "simple" to start.
+ float rpm = _rpm_node->getFloatValue();
+ float factor = rpm / rpm_threshold;
+ if ( factor > 1.0 ) {
+ factor = 1.0;
+ }
+ // cout << "alternator amps = " << amps * factor << endl;
+ float available_amps = ideal_amps * factor;
+ return available_amps - amps;
+ } else if ( model == FG_EXTERNAL ) {
+ // cout << "external amps = " << 0.0 << endl;
+ return available_amps - amps;
+ } else {
+ SG_LOG( SG_ALL, SG_ALERT, "unknown supplier type" );
+ }
+
+ return 0.0;
+}
+
+
+float FGElectricalSupplier::get_output_volts() {
if ( model == FG_BATTERY ) {
// cout << "battery amps = " << amps << endl;
- return amps;
+ float x = 1.0 - percent_remaining;
+ float tmp = -(3.0 * x - 1.0);
+ float factor = (tmp*tmp*tmp*tmp*tmp + 32) / 32;
+ // cout << "battery % = " << percent_remaining <<
+ // " factor = " << factor << endl;
+ // percent_remaining -= 0.001;
+ return ideal_volts * factor;
} else if ( model == FG_ALTERNATOR ) {
// scale alternator output for rpms < 600. For rpms >= 600
// give full output. This is just a WAG, and probably not how
// it really works but I'm keeping things "simple" to start.
- double rpm = _rpm_node->getDoubleValue();
- double factor = rpm / 600.0;
+ float rpm = _rpm_node->getFloatValue();
+ float factor = rpm / rpm_threshold;
if ( factor > 1.0 ) {
factor = 1.0;
}
// cout << "alternator amps = " << amps * factor << endl;
- return amps * factor;
+ return ideal_volts * factor;
} else if ( model == FG_EXTERNAL ) {
// cout << "external amps = " << 0.0 << endl;
- return 0.0;
+ return ideal_volts;
+ } else {
+ SG_LOG( SG_ALL, SG_ALERT, "unknown supplier type" );
+ }
+
+ return 0.0;
+}
+
+
+float FGElectricalSupplier::get_output_amps() {
+ if ( model == FG_BATTERY ) {
+ // cout << "battery amp_hours = " << amp_hours << endl;
+
+ // This is a WAG, but produce enough amps to burn the entire
+ // battery in one minute.
+ return amp_hours * 60.0;
+ } else if ( model == FG_ALTERNATOR ) {
+ // scale alternator output for rpms < 600. For rpms >= 600
+ // give full output. This is just a WAG, and probably not how
+ // it really works but I'm keeping things "simple" to start.
+ float rpm = _rpm_node->getFloatValue();
+ float factor = rpm / rpm_threshold;
+ if ( factor > 1.0 ) {
+ factor = 1.0;
+ }
+ // cout << "alternator amps = " << ideal_amps * factor << endl;
+ return ideal_amps * factor;
+ } else if ( model == FG_EXTERNAL ) {
+ // cout << "external amps = " << 0.0 << endl;
+ return ideal_amps;
} else {
SG_LOG( SG_ALL, SG_ALERT, "unknown supplier type" );
}
FGElectricalOutput::FGElectricalOutput ( SGPropertyNode *node ) {
kind = FG_OUTPUT;
- output_amps = 0.1; // arbitrary default value
+ load_amps = 0.1; // arbitrary default value
name = node->getStringValue("name");
SGPropertyNode *draw = node->getNode("rated-draw");
if ( draw != NULL ) {
- output_amps = draw->getDoubleValue();
+ load_amps = draw->getFloatValue();
}
// cout << "rated draw = " << output_amps << endl;
s->add_input( this );
} else if ( s->get_kind() == FG_OUTPUT ) {
s->add_input( this );
+ } else if ( s->get_kind() == FG_SUPPLIER &&
+ ((FGElectricalSupplier *)s)->get_model()
+ == FGElectricalSupplier::FG_BATTERY ) {
+ s->add_output( this );
} else {
SG_LOG( SG_ALL, SG_ALERT,
"Attempt to connect to something that can't provide an input: "
}
-FGElectricalSystem::FGElectricalSystem () :
+FGElectricalSystem::FGElectricalSystem ( SGPropertyNode *node ) :
+ name("electrical"),
+ num(0),
+ path(""),
enabled(false)
{
+ int i;
+ for ( i = 0; i < node->nChildren(); ++i ) {
+ SGPropertyNode *child = node->getChild(i);
+ string cname = child->getName();
+ string cval = child->getStringValue();
+ if ( cname == "name" ) {
+ name = cval;
+ } else if ( cname == "number" ) {
+ num = child->getIntValue();
+ } else if ( cname == "path" ) {
+ path = cval;
+ } else {
+ SG_LOG( SG_SYSTEMS, SG_WARN,
+ "Error in electrical system config logic" );
+ if ( name.length() ) {
+ SG_LOG( SG_SYSTEMS, SG_WARN, "Section = " << name );
+ }
+ }
+ }
}
void FGElectricalSystem::init () {
config_props = new SGPropertyNode;
- SGPropertyNode *path_n = fgGetNode("/sim/systems/electrical/path");
_volts_out = fgGetNode( "/systems/electrical/volts", true );
_amps_out = fgGetNode( "/systems/electrical/amps", true );
- if (path_n) {
+ // allow the electrical system to be specified via the
+ // aircraft-set.xml file (for backwards compatibility) or through
+ // the aircraft-systems.xml file. If a -set.xml entry is
+ // specified, that overrides the system entry.
+ SGPropertyNode *path_n = fgGetNode("/sim/systems/electrical/path");
+ if ( path_n ) {
+ if ( path.length() ) {
+ SG_LOG( SG_ALL, SG_ALERT,
+ "NOTICE: System manager configuration specifies an " <<
+ "electrical system model from: " << path << " but it is " <<
+ "being overridden by the one specified in the -set.xml " <<
+ "file: " << path_n->getStringValue() );
+ }
+
+ path = path_n->getStringValue();
+ }
+
+ if ( path.length() ) {
SGPath config( globals->get_fg_root() );
- config.append( path_n->getStringValue() );
+ config.append( path );
- SG_LOG( SG_ALL, SG_INFO, "Reading electrical system model from "
+ SG_LOG( SG_ALL, SG_ALERT, "Reading electrical system model from "
<< config.str() );
try {
readProperties( config.str(), config_props );
} else {
SG_LOG( SG_ALL, SG_WARN,
- "No electrical model specified for this model!");
+ "No xml-based electrical model specified for this model!");
+ }
+
+ if ( !enabled ) {
+ _amps_out->setDoubleValue(0);
}
delete config_props;
void FGElectricalSystem::update (double dt) {
if ( !enabled ) {
- _amps_out->setDoubleValue(0);
return;
}
- // cout << "Updating electrical system" << endl;
+ // cout << "Updating electrical system, dt = " << dt << endl;
unsigned int i;
- // zero everything out before we start
+ // zero out the voltage before we start, but don't clear the
+ // requested load values.
for ( i = 0; i < suppliers.size(); ++i ) {
suppliers[i]->set_volts( 0.0 );
- suppliers[i]->set_load_amps( 0.0 );
}
for ( i = 0; i < buses.size(); ++i ) {
buses[i]->set_volts( 0.0 );
- buses[i]->set_load_amps( 0.0 );
}
for ( i = 0; i < outputs.size(); ++i ) {
outputs[i]->set_volts( 0.0 );
- outputs[i]->set_load_amps( 0.0 );
}
for ( i = 0; i < connectors.size(); ++i ) {
connectors[i]->set_volts( 0.0 );
- connectors[i]->set_load_amps( 0.0 );
}
- // for each supplier, propagate the electrical current
+ // for each "external" supplier, propagate the electrical current
+ for ( i = 0; i < suppliers.size(); ++i ) {
+ FGElectricalSupplier *node = (FGElectricalSupplier *)suppliers[i];
+ if ( node->get_model() == FGElectricalSupplier::FG_EXTERNAL ) {
+ float load;
+ // cout << "Starting propagation: " << suppliers[i]->get_name()
+ // << endl;
+ load = propagate( suppliers[i], dt,
+ node->get_output_volts(),
+ node->get_output_amps(),
+ " " );
+
+ if ( node->apply_load( load, dt ) < 0.0 ) {
+ cout << "Error drawing more current than available!" << endl;
+ }
+ }
+ }
+
+ // for each "alternator" supplier, propagate the electrical
+ // current
for ( i = 0; i < suppliers.size(); ++i ) {
- // cout << " Updating: " << suppliers[i]->get_name() << endl;
- propagate( suppliers[i], 0.0, " " );
+ FGElectricalSupplier *node = (FGElectricalSupplier *)suppliers[i];
+ if ( node->get_model() == FGElectricalSupplier::FG_ALTERNATOR) {
+ float load;
+ // cout << "Starting propagation: " << suppliers[i]->get_name()
+ // << endl;
+ load = propagate( suppliers[i], dt,
+ node->get_output_volts(),
+ node->get_output_amps(),
+ " " );
+
+ if ( node->apply_load( load, dt ) < 0.0 ) {
+ cout << "Error drawing more current than available!" << endl;
+ }
+ }
}
- double alt_norm
- = fgGetDouble("/systems/electrical/suppliers/alternator") / 60.0;
+ // for each "battery" supplier, propagate the electrical
+ // current
+ for ( i = 0; i < suppliers.size(); ++i ) {
+ FGElectricalSupplier *node = (FGElectricalSupplier *)suppliers[i];
+ if ( node->get_model() == FGElectricalSupplier::FG_BATTERY ) {
+ float load;
+ // cout << "Starting propagation: " << suppliers[i]->get_name()
+ // << endl;
+ load = propagate( suppliers[i], dt,
+ node->get_output_volts(),
+ node->get_output_amps(),
+ " " );
+ // cout << "battery load = " << load << endl;
+
+ if ( node->apply_load( load, dt ) < 0.0 ) {
+ cout << "Error drawing more current than available!" << endl;
+ }
+ }
+ }
+
+ float alt_norm
+ = fgGetFloat("/systems/electrical/suppliers/alternator") / 60.0;
// impliment an extremely simplistic voltage model (assumes
// certain naming conventions in electrical system config)
// FIXME: we probably want to be able to feed power from all
// engines if they are running and the master-alt is switched on
- double volts = 0.0;
+ float volts = 0.0;
if ( fgGetBool("/controls/engines/engine[0]/master-bat") ) {
volts = 24.0;
}
if ( fgGetBool("/controls/engines/engine[0]/master-alt") ) {
- if ( fgGetDouble("/engines/engine[0]/rpm") > 800 ) {
- double alt_contrib = 28.0;
+ if ( fgGetFloat("/engines/engine[0]/rpm") > 800 ) {
+ float alt_contrib = 28.0;
if ( alt_contrib > volts ) {
volts = alt_contrib;
}
- } else if ( fgGetDouble("/engines/engine[0]/rpm") > 200 ) {
- double alt_contrib = 20.0;
+ } else if ( fgGetFloat("/engines/engine[0]/rpm") > 200 ) {
+ float alt_contrib = 20.0;
if ( alt_contrib > volts ) {
volts = alt_contrib;
}
}
}
- _volts_out->setDoubleValue( volts );
+ _volts_out->setFloatValue( volts );
// impliment an extremely simplistic amps model (assumes certain
// naming conventions in the electrical system config) ... FIXME:
// make this more generic
- double amps = 0.0;
+ float amps = 0.0;
if ( fgGetBool("/controls/engines/engine[0]/master-bat") ) {
if ( fgGetBool("/controls/engines/engine[0]/master-alt") &&
- fgGetDouble("/engines/engine[0]/rpm") > 800 )
+ fgGetFloat("/engines/engine[0]/rpm") > 800 )
{
amps += 40.0 * alt_norm;
}
amps = 7.0;
}
}
- _amps_out->setDoubleValue( amps );
+ _amps_out->setFloatValue( amps );
}
// propagate the electrical current through the network, returns the
// total current drawn by the children of this node.
-float FGElectricalSystem::propagate( FGElectricalComponent *node, double val,
- string s ) {
+float FGElectricalSystem::propagate( FGElectricalComponent *node, double dt,
+ float input_volts, float input_amps,
+ string s ) {
s += " ";
- float current_amps = 0.0;
+ float total_load = 0.0;
// determine the current to carry forward
- double volts = 0.0;
+ float volts = 0.0;
if ( !fgGetBool("/systems/electrical/serviceable") ) {
volts = 0;
- } else if ( node->get_kind() == FG_SUPPLIER ) {
- // cout << s << " is a supplier" << endl;
- volts = ((FGElectricalSupplier *)node)->get_output();
- } else if ( node->get_kind() == FG_BUS ) {
- // cout << s << " is a bus" << endl;
- volts = val;
- } else if ( node->get_kind() == FG_OUTPUT ) {
- // cout << s << " is an output" << endl;
- volts = val;
+ } else if ( node->get_kind() == FGElectricalComponent::FG_SUPPLIER ) {
+ // cout << s << "is a supplier (" << node->get_name() << ")" << endl;
+ FGElectricalSupplier *supplier = (FGElectricalSupplier *)node;
+ if ( supplier->get_model() == FGElectricalSupplier::FG_BATTERY ) {
+ // cout << s << " (and is a battery)" << endl;
+ float battery_volts = supplier->get_output_volts();
+ if ( battery_volts < (input_volts - 0.1) ) {
+ // special handling of a battery charge condition
+ // cout << s << " (and is being charged) in v = "
+ // << input_volts << " current v = " << battery_volts
+ // << endl;
+ supplier->apply_load( -supplier->get_charge_amps(), dt );
+ return supplier->get_charge_amps();
+ }
+ }
+ volts = input_volts;
+ } else if ( node->get_kind() == FGElectricalComponent::FG_BUS ) {
+ // cout << s << "is a bus (" << node->get_name() << ")" << endl;
+ volts = input_volts;
+ } else if ( node->get_kind() == FGElectricalComponent::FG_OUTPUT ) {
+ // cout << s << "is an output (" << node->get_name() << ")" << endl;
+ volts = input_volts;
if ( volts > 1.0 ) {
// draw current if we have voltage
- current_amps = ((FGElectricalOutput *)node)->get_output_amps();
+ total_load = node->get_load_amps();
}
- } else if ( node->get_kind() == FG_CONNECTOR ) {
- // cout << s << " is a connector" << endl;
+ } else if ( node->get_kind() == FGElectricalComponent::FG_CONNECTOR ) {
+ // cout << s << "is a connector (" << node->get_name() << ")" << endl;
if ( ((FGElectricalConnector *)node)->get_state() ) {
- volts = val;
+ volts = input_volts;
} else {
volts = 0.0;
}
- // cout << s << " val = " << volts << endl;
+ // cout << s << " input_volts = " << volts << endl;
} else {
SG_LOG( SG_ALL, SG_ALERT, "unkown node type" );
}
+ int i;
+
+ // if this node has found a stronger power source, update the
+ // value and propagate to all children
if ( volts > node->get_volts() ) {
node->set_volts( volts );
- }
+ for ( i = 0; i < node->get_num_outputs(); ++i ) {
+ FGElectricalComponent *child = node->get_output(i);
+ // send current equal to load
+ total_load += propagate( child, dt,
+ volts, child->get_load_amps(),
+ s );
+ }
- int i;
+ // if not an output node, register the downstream current draw
+ // (sum of all children) with this node. If volts are zero,
+ // current draw should be zero.
+ if ( node->get_kind() != FGElectricalComponent::FG_OUTPUT ) {
+ node->set_load_amps( total_load );
+ }
- // publish values to specified properties
- for ( i = 0; i < node->get_num_props(); ++i ) {
- fgSetDouble( node->get_prop(i).c_str(), node->get_volts() );
- }
- // cout << s << node->get_name() << " -> " << node->get_value() << endl;
+ node->set_available_amps( input_amps - total_load );
- // propagate to all children
- for ( i = 0; i < node->get_num_outputs(); ++i ) {
- current_amps += propagate( node->get_output(i), volts, s );
- }
+ // publish values to specified properties
+ for ( i = 0; i < node->get_num_props(); ++i ) {
+ fgSetFloat( node->get_prop(i).c_str(), node->get_volts() );
+ }
- // if not an output node, register the downstream current draw
- // with this node. If volts are zero, current draw should be zero.
- if ( node->get_kind() != FG_OUTPUT ) {
- node->set_load_amps( current_amps );
+ /*
+ cout << s << node->get_name() << " -> (volts) " << node->get_volts()
+ << endl;
+ cout << s << node->get_name() << " -> (load amps) " << total_load
+ << endl;
+ cout << s << node->get_name() << " -> (input amps) " << input_amps
+ << endl;
+ cout << s << node->get_name() << " -> (extra amps) "
+ << node->get_available_amps() << endl;
+ */
+
+ return total_load;
+ } else {
+ // cout << s << "no further propagation" << endl;
+ return 0.0;
}
- // cout << s << node->get_name() << " -> " << current_amps << endl;
-
- return current_amps;
}
projects / flightgear.git / commitdiff