1 // electrical.cxx - a flexible, generic electrical system model.
3 // Written by Curtis Olson, started September 2002.
5 // Copyright (C) 2002 Curtis L. Olson - curt@flightgear.org
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 #include <simgear/misc/exception.hxx>
25 #include <simgear/misc/sg_path.hxx>
27 #include <Main/fg_props.hxx>
28 #include <Main/globals.hxx>
30 #include "electrical.hxx"
33 FGElectricalComponent::FGElectricalComponent() :
41 FGElectricalSupplier::FGElectricalSupplier ( SGPropertyNode *node ) {
44 // cout << "Creating a supplier" << endl;
45 name = node->getStringValue("name");
46 string _model = node->getStringValue("kind");
47 // cout << "_model = " << _model << endl;
48 if ( _model == "battery" ) {
50 } else if ( _model == "alternator" ) {
51 model = FG_ALTERNATOR;
52 } else if ( _model == "external" ) {
57 volts = node->getDoubleValue("volts");
58 amps = node->getDoubleValue("amps");
61 for ( i = 0; i < node->nChildren(); ++i ) {
62 SGPropertyNode *child = node->getChild(i);
63 // cout << " scanning: " << child->getName() << endl;
64 if ( (string)child->getName() == "prop" ) {
65 string prop = child->getStringValue();
66 // cout << " Adding prop = " << prop << endl;
68 fgSetDouble( prop.c_str(), amps );
72 _rpm_node = fgGetNode("/engines/engine[0]/rpm", true);
76 double FGElectricalSupplier::get_output() {
77 if ( model == FG_BATTERY ) {
78 // cout << "battery amps = " << amps << endl;
80 } else if ( model == FG_ALTERNATOR ) {
81 // scale alternator output for rpms < 600. For rpms >= 600
82 // give full output. This is just a WAG, and probably not how
83 // it really works but I'm keeping things "simple" to start.
84 double rpm = _rpm_node->getDoubleValue();
85 double factor = rpm / 600.0;
89 // cout << "alternator amps = " << amps * factor << endl;
91 } else if ( model == FG_EXTERNAL ) {
92 // cout << "external amps = " << 0.0 << endl;
95 SG_LOG( SG_ALL, SG_ALERT, "unknown supplier type" );
102 FGElectricalBus::FGElectricalBus ( SGPropertyNode *node ) {
105 name = node->getStringValue("name");
107 for ( i = 0; i < node->nChildren(); ++i ) {
108 SGPropertyNode *child = node->getChild(i);
109 if ( (string)child->getName() == "prop" ) {
110 string prop = child->getStringValue();
117 FGElectricalOutput::FGElectricalOutput ( SGPropertyNode *node ) {
120 name = node->getStringValue("name");
122 for ( i = 0; i < node->nChildren(); ++i ) {
123 SGPropertyNode *child = node->getChild(i);
124 if ( (string)child->getName() == "prop" ) {
125 string prop = child->getStringValue();
132 FGElectricalConnector::FGElectricalConnector ( SGPropertyNode *node,
133 FGElectricalSystem *es ) {
137 for ( i = 0; i < node->nChildren(); ++i ) {
138 SGPropertyNode *child = node->getChild(i);
139 string cname = child->getName();
140 string cval = child->getStringValue();
141 // cout << " " << cname << " = " << cval << endl;
142 if ( cname == "input" ) {
143 FGElectricalComponent *s = es->find( child->getStringValue() );
146 if ( s->get_kind() == FG_SUPPLIER ) {
147 s->add_output( this );
148 } else if ( s->get_kind() == FG_BUS ) {
149 s->add_output( this );
151 SG_LOG( SG_ALL, SG_ALERT,
152 "Attempt to connect to something that can't provide an output: "
153 << child->getStringValue() );
156 SG_LOG( SG_ALL, SG_ALERT, "Can't find named source: "
157 << child->getStringValue() );
159 } else if ( cname == "output" ) {
160 FGElectricalComponent *s = es->find( child->getStringValue() );
163 if ( s->get_kind() == FG_BUS ) {
164 s->add_input( this );
165 } else if ( s->get_kind() == FG_OUTPUT ) {
166 s->add_input( this );
168 SG_LOG( SG_ALL, SG_ALERT,
169 "Attempt to connect to something that can't provide an input: "
170 << child->getStringValue() );
173 SG_LOG( SG_ALL, SG_ALERT, "Can't find named source: "
174 << child->getStringValue() );
176 } else if ( cname == "switch" ) {
177 // set default value of switch to true
178 // cout << "Switch = " << child->getStringValue() << endl;
179 fgSetBool( child->getStringValue(), true );
180 add_switch( fgGetNode( child->getStringValue(), true ) );
186 // return true if all switches are true, false otherwise. A connector
187 // could have multiple switches, but they all need to be true(closed)
188 // for current to get through.
189 bool FGElectricalConnector::get_state() {
191 for ( i = 0; i < switches.size(); ++i ) {
192 if ( ! switches[i]->getBoolValue() ) {
201 FGElectricalSystem::FGElectricalSystem () :
207 FGElectricalSystem::~FGElectricalSystem () {
211 void FGElectricalSystem::init () {
212 config_props = new SGPropertyNode;
214 SGPath config( globals->get_fg_root() );
215 config.append( fgGetString("/sim/systems/electrical/path") );
217 SG_LOG( SG_ALL, SG_ALERT, "Reading electrical system model from "
220 readProperties( config.str(), config_props );
225 SG_LOG( SG_ALL, SG_ALERT,
226 "Detected an internal inconsistancy in the electrical" );
227 SG_LOG( SG_ALL, SG_ALERT,
228 " system specification file. See earlier errors for" );
229 SG_LOG( SG_ALL, SG_ALERT,
233 } catch (const sg_exception& exc) {
234 SG_LOG( SG_ALL, SG_ALERT, "Failed to load electrical system model: "
242 void FGElectricalSystem::bind () {
246 void FGElectricalSystem::unbind () {
250 void FGElectricalSystem::update (double dt) {
255 // cout << "Updating electrical system" << endl;
259 // zero everything out before we start
260 for ( i = 0; i < suppliers.size(); ++i ) {
261 suppliers[i]->set_value( 0.0 );
263 for ( i = 0; i < buses.size(); ++i ) {
264 buses[i]->set_value( 0.0 );
266 for ( i = 0; i < outputs.size(); ++i ) {
267 outputs[i]->set_value( 0.0 );
269 for ( i = 0; i < connectors.size(); ++i ) {
270 connectors[i]->set_value( 0.0 );
273 // for each supplier, propogate the electrical current
274 for ( i = 0; i < suppliers.size(); ++i ) {
275 // cout << " Updating: " << suppliers[i]->get_name() << endl;
276 propogate( suppliers[i], 0.0, " " );
282 bool FGElectricalSystem::build () {
283 SGPropertyNode *node;
286 int count = config_props->nChildren();
287 for ( i = 0; i < count; ++i ) {
288 node = config_props->getChild(i);
289 string name = node->getName();
290 // cout << name << endl;
291 if ( name == "supplier" ) {
292 FGElectricalSupplier *s =
293 new FGElectricalSupplier( node );
294 suppliers.push_back( s );
295 } else if ( name == "bus" ) {
297 new FGElectricalBus( node );
298 buses.push_back( b );
299 } else if ( name == "output" ) {
300 FGElectricalOutput *o =
301 new FGElectricalOutput( node );
302 outputs.push_back( o );
303 } else if ( name == "connector" ) {
304 FGElectricalConnector *c =
305 new FGElectricalConnector( node, this );
306 connectors.push_back( c );
308 SG_LOG( SG_ALL, SG_ALERT, "Unknown component type specified: "
318 // propogate the electrical current through the network
319 void FGElectricalSystem::propogate( FGElectricalComponent *node, double val,
323 // determine the current to carry forward
324 double current = 0.0;
325 if ( node->get_kind() == FG_SUPPLIER ) {
326 // cout << s << " is a supplier" << endl;
327 current = ((FGElectricalSupplier *)node)->get_output();
328 } else if ( node->get_kind() == FG_BUS ) {
329 // cout << s << " is a bus" << endl;
331 } else if ( node->get_kind() == FG_OUTPUT ) {
332 // cout << s << " is an output" << endl;
334 } else if ( node->get_kind() == FG_CONNECTOR ) {
335 // cout << s << " is a connector" << endl;
336 if ( ((FGElectricalConnector *)node)->get_state() ) {
341 // cout << s << " val = " << current << endl;
343 SG_LOG( SG_ALL, SG_ALERT, "unkown node type" );
346 if ( current > node->get_value() ) {
347 node->set_value( current );
352 // publish values to specified properties
353 for ( i = 0; i < node->get_num_props(); ++i ) {
354 fgSetDouble( node->get_prop(i).c_str(), node->get_value() );
356 // cout << s << node->get_name() << " -> " << node->get_value() << endl;
358 // propogate to all children
359 for ( i = 0; i < node->get_num_outputs(); ++i ) {
360 propogate( node->get_output(i), current, s );
365 // search for the named component and return a pointer to it, NULL otherwise
366 FGElectricalComponent *FGElectricalSystem::find ( const string &name ) {
371 for ( i = 0; i < suppliers.size(); ++i ) {
372 s = suppliers[i]->get_name();
373 // cout << " " << s << endl;
380 for ( i = 0; i < buses.size(); ++i ) {
381 s = buses[i]->get_name();
382 // cout << " " << s << endl;
388 // then search outputs
389 for ( i = 0; i < outputs.size(); ++i ) {
390 s = outputs[i]->get_name();
391 // cout << " " << s << endl;