src/AIModel/AIShip.cxx

   1 // FGAIShip - FGAIBase-derived class creates an AI ship
   2 //
   3 // Written by David Culp, started October 2003.
   4 // with major amendments and additions by Vivian Meazza, 2004 - 2007
   5 //
   6 // This program is free software; you can redistribute it and/or
   7 // modify it under the terms of the GNU General Public License as
   8 // published by the Free Software Foundation; either version 2 of the
   9 // License, or (at your option) any later version.
  10 //
  11 // This program is distributed in the hope that it will be useful, but
  12 // WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 // General Public License for more details.
  15 //
  16 // You should have received a copy of the GNU General Public License
  17 // along with this program; if not, write to the Free Software
  18 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  19
  20 #ifdef HAVE_CONFIG_H
  21 #  include <config.h>
  22 #endif
  23
  24 #ifdef _MSC_VER
  25 #  include <float.h>
  26 #  define finite _finite
  27 #elif defined(__sun) || defined(sgi)
  28 #  include <ieeefp.h>
  29 #endif
  30
  31 #include <math.h>
  32
  33 #include <simgear/sg_inlines.h>
  34 #include <simgear/math/sg_geodesy.hxx>
  35 #include <simgear/timing/sg_time.hxx>
  36 #include <simgear/math/sg_random.h>
  37
  38 #include <simgear/scene/util/SGNodeMasks.hxx>
  39 #include <Scenery/scenery.hxx>
  40
  41 #include "AIShip.hxx"
  42
  43
  44 FGAIShip::FGAIShip(object_type ot) :
  45 FGAIBase(ot),
  46 _limit(40),
  47 _elevation_m(0),
  48 _elevation_ft(0),
  49 _tow_angle(0),
  50 _dt_count(0),
  51 _next_run(0),
  52 _lead_angle(0),
  53 _xtrack_error(0),
  54 _tunnel(false),
  55 _curr_alt(0),
  56 _prev_alt(0),
  57 _until_time(""),
  58 _fp_init(false),
  59 _missed(false),
  60 _waiting(false),
  61 _new_waypoint(true),
  62 _missed_count(0),
  63 _wait_count(0),
  64 _missed_time_sec(30),
  65 _day(86400),
  66 _wp_range(0),
  67 _old_range(0),
  68 _range_rate(0),
  69 _roll_constant(0.001),
  70 _hdg_constant(0.01),
  71 _roll_factor(-0.0083335),
  72 _restart(false)
  73
  74 {
  75         invisible = false;
  76 }
  77
  78 FGAIShip::~FGAIShip() {
  79 }
  80
  81 void FGAIShip::readFromScenario(SGPropertyNode* scFileNode) {
  82
  83     if (!scFileNode)
  84         return;
  85
  86     FGAIBase::readFromScenario(scFileNode);
  87
  88     setRudder(scFileNode->getFloatValue("rudder", 0.0));
  89     setName(scFileNode->getStringValue("name", "Titanic"));
  90     setRadius(scFileNode->getDoubleValue("turn-radius-ft", 2000));
  91     std::string flightplan = scFileNode->getStringValue("flightplan");
  92     setRepeat(scFileNode->getBoolValue("repeat", false));
  93     setRestart(scFileNode->getBoolValue("restart", false));
  94     setStartTime(scFileNode->getStringValue("time", ""));
  95     setLeadAngleGain(scFileNode->getDoubleValue("lead-angle-gain", 1.5));
  96     setLeadAngleLimit(scFileNode->getDoubleValue("lead-angle-limit-deg", 15));
  97     setLeadAngleProp(scFileNode->getDoubleValue("lead-angle-proportion", 0.75));
  98     setRudderConstant(scFileNode->getDoubleValue("rudder-constant", 0.5));
  99     setFixedTurnRadius(scFileNode->getDoubleValue("fixed-turn-radius-ft", 500));
 100     setSpeedConstant(scFileNode->getDoubleValue("speed-constant", 0.5));
 101
 102     if (!flightplan.empty()) {
 103         SG_LOG(SG_GENERAL, SG_ALERT, "getting flightplan: " << _name );
 104
 105         FGAIFlightPlan* fp = new FGAIFlightPlan(flightplan);
 106         setFlightPlan(fp);
 107     }
 108
 109 }
 110
 111 bool FGAIShip::init(bool search_in_AI_path) {
 112     prev = 0; // the one behind you
 113     curr = 0; // the one ahead
 114     next = 0; // the next plus 1
 115
 116     props->setStringValue("name", _name.c_str());
 117     props->setStringValue("waypoint/name-prev", _prev_name.c_str());
 118     props->setStringValue("waypoint/name-curr", _curr_name.c_str());
 119     props->setStringValue("waypoint/name-next", _next_name.c_str());
 120     props->setStringValue("submodels/path", _path.c_str());
 121     props->setStringValue("waypoint/start-time", _start_time.c_str());
 122     props->setStringValue("waypoint/wait-until-time", _until_time.c_str());
 123
 124     _hdg_lock = false;
 125     _rudder = 0.0;
 126     no_roll = false;
 127
 128     _rd_turn_radius_ft = _sp_turn_radius_ft = turn_radius_ft;
 129
 130     if (fp)
 131         _fp_init = initFlightPlan();
 132
 133     return FGAIBase::init(search_in_AI_path);
 134 }
 135
 136 void FGAIShip::bind() {
 137     FGAIBase::bind();
 138
 139     props->tie("surface-positions/rudder-pos-deg",
 140         SGRawValuePointer<float>(&_rudder));
 141     props->tie("controls/heading-lock",
 142         SGRawValuePointer<bool>(&_hdg_lock));
 143     props->tie("controls/tgt-speed-kts",
 144         SGRawValuePointer<double>(&tgt_speed));
 145     props->tie("controls/tgt-heading-degs",
 146         SGRawValuePointer<double>(&tgt_heading));
 147     props->tie("controls/constants/rudder",
 148         SGRawValuePointer<double>(&_rudder_constant));
 149     props->tie("controls/constants/roll-factor",
 150         SGRawValuePointer<double>(&_roll_factor));
 151     props->tie("controls/constants/roll",
 152         SGRawValuePointer<double>(&_roll_constant));
 153     props->tie("controls/constants/rudder",
 154         SGRawValuePointer<double>(&_rudder_constant));
 155     props->tie("controls/constants/speed",
 156         SGRawValuePointer<double>(&_speed_constant));
 157     props->tie("waypoint/range-nm",
 158         SGRawValuePointer<double>(&_wp_range));
 159     props->tie("waypoint/brg-deg",
 160         SGRawValuePointer<double>(&_course));
 161     props->tie("waypoint/rangerate-nm-sec",
 162         SGRawValuePointer<double>(&_range_rate));
 163     props->tie("waypoint/new",
 164         SGRawValuePointer<bool>(&_new_waypoint));
 165     props->tie("waypoint/missed",
 166         SGRawValuePointer<bool>(&_missed));
 167     props->tie("waypoint/missed-count-sec",
 168         SGRawValuePointer<double>(&_missed_count));
 169     props->tie("waypoint/missed-range-nm",
 170         SGRawValuePointer<double>(&_missed_range));
 171     props->tie("waypoint/missed-time-sec",
 172         SGRawValuePointer<double>(&_missed_time_sec));
 173     props->tie("waypoint/wait-count-sec",
 174         SGRawValuePointer<double>(&_wait_count));
 175     props->tie("waypoint/xtrack-error-ft",
 176         SGRawValuePointer<double>(&_xtrack_error));
 177     props->tie("waypoint/waiting",
 178         SGRawValuePointer<bool>(&_waiting));
 179     props->tie("waypoint/lead-angle-deg",
 180         SGRawValuePointer<double>(&_lead_angle));
 181     props->tie("waypoint/tunnel",
 182         SGRawValuePointer<bool>(&_tunnel));
 183     props->tie("waypoint/alt-curr-m",
 184         SGRawValuePointer<double>(&_curr_alt));
 185     props->tie("waypoint/alt-prev-m",
 186         SGRawValuePointer<double>(&_prev_alt));
 187     props->tie("submodels/serviceable",
 188         SGRawValuePointer<bool>(&_serviceable));
 189     props->tie("controls/turn-radius-ft",
 190         SGRawValuePointer<double>(&turn_radius_ft));
 191     props->tie("controls/turn-radius-corrected-ft",
 192         SGRawValuePointer<double>(&_rd_turn_radius_ft));
 193     props->tie("controls/constants/lead-angle/gain",
 194         SGRawValuePointer<double>(&_lead_angle_gain));
 195     props->tie("controls/constants/lead-angle/limit-deg",
 196         SGRawValuePointer<double>(&_lead_angle_limit));
 197     props->tie("controls/constants/lead-angle/proportion",
 198         SGRawValuePointer<double>(&_proportion));
 199     props->tie("controls/fixed-turn-radius-ft",
 200         SGRawValuePointer<double>(&_fixed_turn_radius));
 201     props->tie("controls/restart",
 202         SGRawValuePointer<bool>(&_restart));
 203 }
 204
 205 void FGAIShip::unbind() {
 206     FGAIBase::unbind();
 207     props->untie("surface-positions/rudder-pos-deg");
 208     props->untie("controls/heading-lock");
 209     props->untie("controls/tgt-speed-kts");
 210     props->untie("controls/tgt-heading-degs");
 211     props->untie("controls/constants/roll");
 212     props->untie("controls/constants/rudder");
 213     props->untie("controls/constants/roll-factor");
 214     props->untie("controls/constants/speed");
 215     props->untie("waypoint/range-nm");
 216     props->untie("waypoint/range-brg-deg");
 217     props->untie("waypoint/rangerate-nm-sec");
 218     props->untie("waypoint/new");
 219     props->untie("waypoint/missed");
 220     props->untie("waypoint/missed-count-sec");
 221     props->untie("waypoint/missed-time-sec");
 222     props->untie("waypoint/missed-range");
 223     props->untie("waypoint/wait-count-sec");
 224     props->untie("waypoint/lead-angle-deg");
 225     props->untie("waypoint/xtrack-error-ft");
 226     props->untie("waypoint/waiting");
 227     props->untie("waypoint/tunnel");
 228     props->untie("waypoint/alt-curr-m");
 229     props->untie("waypoint/alt-prev-m");
 230     props->untie("submodels/serviceable");
 231     props->untie("controls/turn-radius-ft");
 232     props->untie("controls/turn-radius-corrected-ft");
 233     props->untie("controls/constants/lead-angle/gain");
 234     props->untie("controls/constants/lead-angle/limit-deg");
 235     props->untie("controls/constants/lead-angle/proportion");
 236     props->untie("controls/fixed-turn-radius-ft");
 237     props->untie("controls/constants/speed");
 238     props->untie("controls/restart");
 239
 240 }
 241 void FGAIShip::update(double dt) {
 242     //SG_LOG(SG_GENERAL, SG_ALERT, "updating Ship: " << _name <<hdg<<pitch<<roll);
 243     // For computation of rotation speeds we just use finite differences here.
 244     // That is perfectly valid since this thing is not driven by accelerations
 245     // but by just apply discrete changes at its velocity variables.
 246     // Update the velocity information stored in those nodes.
 247     // Transform that one to the horizontal local coordinate system.
 248     SGQuatd ec2hl = SGQuatd::fromLonLat(pos);
 249     // The orientation of the carrier wrt the horizontal local frame
 250     SGQuatd hl2body = SGQuatd::fromYawPitchRollDeg(hdg, pitch, roll);
 251     // and postrotate the orientation of the AIModel wrt the horizontal
 252     // local frame
 253     SGQuatd ec2body = ec2hl*hl2body;
 254     // The cartesian position of the carrier in the wgs84 world
 255     SGVec3d cartPos = SGVec3d::fromGeod(pos);
 256
 257     // The simulation time this transform is meant for
 258     aip.setReferenceTime(globals->get_sim_time_sec());
 259
 260     // Compute the velocity in m/s in the body frame
 261     aip.setBodyLinearVelocity(SGVec3d(0.51444444*speed, 0, 0));
 262
 263     FGAIBase::update(dt);
 264     Run(dt);
 265     Transform();
 266     if (fp)
 267         setXTrackError();
 268
 269     // Only change these values if we are able to compute them safely
 270     if (SGLimits<double>::min() < dt) {
 271         // Now here is the finite difference ...
 272
 273         // Transform that one to the horizontal local coordinate system.
 274         SGQuatd ec2hlNew = SGQuatd::fromLonLat(pos);
 275         // compute the new orientation
 276         SGQuatd hl2bodyNew = SGQuatd::fromYawPitchRollDeg(hdg, pitch, roll);
 277         // The rotation difference
 278         SGQuatd dOr = inverse(ec2body)*ec2hlNew*hl2bodyNew;
 279         SGVec3d dOrAngleAxis;
 280         dOr.getAngleAxis(dOrAngleAxis);
 281         // divided by the time difference provides a rotation speed vector
 282         dOrAngleAxis /= dt;
 283
 284         aip.setBodyAngularVelocity(dOrAngleAxis);
 285     }
 286 }
 287
 288 void FGAIShip::Run(double dt) {
 289     if (_fp_init)
 290         ProcessFlightPlan(dt);
 291
 292     string type = getTypeString();
 293
 294     double alpha;
 295     double rudder_limit;
 296     double raw_roll;
 297
 298     // adjust speed
 299     double speed_diff = tgt_speed - speed;
 300
 301     if (fabs(speed_diff) > 0.1) {
 302
 303         if (speed_diff > 0.0)
 304             speed += _speed_constant * dt;
 305
 306         if (speed_diff < 0.0)
 307             speed -= _speed_constant * dt;
 308
 309     }
 310
 311     // do not allow unreasonable speeds
 312     if (speed > _limit)
 313         speed = _limit;
 314
 315     // convert speed to degrees per second
 316     speed_north_deg_sec = cos(hdg / SGD_RADIANS_TO_DEGREES)
 317         * speed * 1.686 / ft_per_deg_lat;
 318     speed_east_deg_sec = sin(hdg / SGD_RADIANS_TO_DEGREES)
 319         * speed * 1.686 / ft_per_deg_lon;
 320
 321     // set new position
 322     //cout << _name << " " << type << " run: " << _elevation_m << " " <<_elevation_ft << endl;
 323     pos.setLatitudeDeg(pos.getLatitudeDeg() + speed_north_deg_sec * dt);
 324     pos.setLongitudeDeg(pos.getLongitudeDeg() + speed_east_deg_sec * dt);
 325     pos.setElevationFt(tgt_altitude_ft);
 326     pitch = tgt_pitch;
 327
 328     // adjust heading based on current _rudder angle
 329     if (turn_radius_ft <= 0)
 330         turn_radius_ft = 0; // don't allow nonsense values
 331
 332     if (_rudder > 45)
 333         _rudder = 45;
 334
 335     if (_rudder < -45)
 336         _rudder = -45;
 337
 338
 339     //we assume that at slow speed ships will manoeuvre using engines/bow thruster
 340         if(type == "ship" || type == "carrier"){
 341
 342                 if (fabs(speed)<=5)
 343                         _sp_turn_radius_ft = _fixed_turn_radius;
 344                 else {
 345                         // adjust turn radius for speed. The equation is very approximate.
 346                         // we need to allow for negative speeds
 347                         _sp_turn_radius_ft = 10 * pow ((fabs(speed) - 15), 2) + turn_radius_ft;
 348                 }
 349
 350         } else {
 351
 352                 if (fabs(speed) <= 40)
 353            _sp_turn_radius_ft = _fixed_turn_radius;
 354                 else {
 355                         // adjust turn radius for speed.
 356                         _sp_turn_radius_ft = turn_radius_ft;
 357                 }
 358         }
 359
 360
 361     if (_rudder <= -0.25 || _rudder >= 0.25) {
 362         // adjust turn radius for _rudder angle. The equation is even more approximate.
 363         float a = 19;
 364         float b = -0.2485;
 365         float c = 0.543;
 366
 367         _rd_turn_radius_ft = (a * exp(b * fabs(_rudder)) + c) * _sp_turn_radius_ft;
 368
 369         // calculate the angle, alpha, subtended by the arc traversed in time dt
 370         alpha = ((speed * 1.686 * dt) / _rd_turn_radius_ft) * SG_RADIANS_TO_DEGREES;
 371         //cout << _name << " alpha " << alpha << endl;
 372         // make sure that alpha is applied in the right direction
 373         hdg += alpha * sign(_rudder);
 374
 375         SG_NORMALIZE_RANGE(hdg, 0.0, 360.0);
 376
 377         //adjust roll for rudder angle and speed. Another bit of voodoo
 378         raw_roll = _roll_factor * speed * _rudder;
 379     } else {
 380         // _rudder angle is 0
 381         raw_roll = 0;
 382     }
 383
 384     //low pass filter
 385     if (speed < 0)
 386         roll = -roll;
 387
 388     roll = (raw_roll * _roll_constant) + (roll * (1 - _roll_constant));
 389
 390     // adjust target _rudder angle if heading lock engaged
 391     double rudder_diff = 0.0;
 392     if (_hdg_lock) {
 393         double rudder_sense = 0.0;
 394         double diff = fabs(hdg - tgt_heading);
 395         //cout << "_rudder diff" << diff << endl;
 396         if (diff > 180)
 397             diff = fabs(diff - 360);
 398
 399         double sum = hdg + diff;
 400
 401         if (sum > 360.0)
 402             sum -= 360.0;
 403
 404         if (fabs(sum - tgt_heading)< 1.0)
 405             rudder_sense = 1.0;
 406         else
 407             rudder_sense = -1.0;
 408
 409         if (speed < 0)
 410             rudder_sense = -rudder_sense;
 411
 412         if (diff < 15)
 413             _tgt_rudder = diff * rudder_sense;
 414         else
 415             _tgt_rudder = 45 * rudder_sense;
 416
 417         rudder_diff = _tgt_rudder - _rudder;
 418     }
 419
 420     // set the _rudder limit by speed
 421     if (type == "ship" || type == "carrier"){
 422
 423         if (speed <= 40)
 424             rudder_limit = (-0.825 * speed) + 35;
 425         else
 426             rudder_limit = 2;
 427
 428     } else
 429         rudder_limit = 20;
 430
 431     if (fabs(rudder_diff)> 0.1) { // apply dead zone
 432
 433         if (rudder_diff > 0.0) {
 434             _rudder += _rudder_constant * dt;
 435
 436             if (_rudder > rudder_limit) // apply the _rudder limit
 437                 _rudder = rudder_limit;
 438
 439         } else if (rudder_diff < 0.0) {
 440             _rudder -= _rudder_constant * dt;
 441
 442             if (_rudder < -rudder_limit)
 443                 _rudder = -rudder_limit;
 444
 445         }
 446
 447         // do calculations for radar
 448         UpdateRadar(manager);
 449     }
 450 }//end function
 451
 452 void FGAIShip::AccelTo(double speed) {
 453     tgt_speed = speed;
 454 }
 455
 456 void FGAIShip::PitchTo(double angle) {
 457     tgt_pitch = angle;
 458 }
 459
 460 void FGAIShip::RollTo(double angle) {
 461     tgt_roll = angle;
 462 }
 463
 464 void FGAIShip::YawTo(double angle) {
 465 }
 466
 467 void FGAIShip::ClimbTo(double altitude) {
 468     tgt_altitude_ft = altitude;
 469     _setAltitude(altitude);
 470 }
 471
 472 void FGAIShip::TurnTo(double heading) {
 473     tgt_heading = heading - _lead_angle + _tow_angle;
 474     SG_NORMALIZE_RANGE(tgt_heading, 0.0, 360.0);
 475     _hdg_lock = true;
 476 }
 477
 478 double FGAIShip::sign(double x) {
 479     if (x < 0.0)
 480         return -1.0;
 481     else
 482         return 1.0;
 483 }
 484
 485 void FGAIShip::setFlightPlan(FGAIFlightPlan* f) {
 486     fp = f;
 487 }
 488
 489 void FGAIShip::setName(const string& n) {
 490     _name = n;
 491 }
 492
 493 void FGAIShip::setStartTime(const string& st) {
 494     _start_time = st;
 495 }
 496
 497 void FGAIShip::setUntilTime(const string& ut) {
 498     _until_time = ut;
 499     props->setStringValue("waypoint/wait-until-time", _until_time.c_str());
 500 }
 501
 502 void FGAIShip::setCurrName(const string& c) {
 503     _curr_name = c;
 504     props->setStringValue("waypoint/name-curr", _curr_name.c_str());
 505 }
 506
 507 void FGAIShip::setNextName(const string& n) {
 508     _next_name = n;
 509     props->setStringValue("waypoint/name-next", _next_name.c_str());
 510 }
 511
 512 void FGAIShip::setPrevName(const string& p) {
 513     _prev_name = p;
 514     props->setStringValue("waypoint/name-prev", _prev_name.c_str());
 515 }
 516
 517 void FGAIShip::setRepeat(bool r) {
 518     _repeat = r;
 519 }
 520
 521 void FGAIShip::setRestart(bool r) {
 522     _restart = r;
 523 }
 524
 525 void FGAIShip::setMissed(bool m) {
 526     _missed = m;
 527     props->setBoolValue("waypoint/missed", _missed);
 528 }
 529
 530 void FGAIShip::setRudder(float r) {
 531     _rudder = r;
 532 }
 533
 534 void FGAIShip::setRoll(double rl) {
 535     roll = rl;
 536 }
 537
 538 void FGAIShip::setLeadAngleGain(double g) {
 539     _lead_angle_gain = g;
 540 }
 541
 542 void FGAIShip::setLeadAngleLimit(double l) {
 543     _lead_angle_limit = l;
 544 }
 545
 546 void FGAIShip::setLeadAngleProp(double p) {
 547     _proportion = p;
 548 }
 549
 550 void FGAIShip::setRudderConstant(double rc) {
 551     _rudder_constant = rc;
 552 }
 553
 554 void FGAIShip::setSpeedConstant(double sc) {
 555     _speed_constant = sc;
 556 }
 557
 558 void FGAIShip::setFixedTurnRadius(double ftr) {
 559     _fixed_turn_radius = ftr;
 560 }
 561
 562 void FGAIShip::setInitialTunnel(bool t) {
 563     _initial_tunnel = t;
 564     setTunnel(_initial_tunnel);
 565 }
 566
 567 void FGAIShip::setTunnel(bool t) {
 568     _tunnel = t;
 569 }
 570
 571 void FGAIShip::setWPNames() {
 572
 573     if (prev != 0)
 574         setPrevName(prev->name);
 575     else
 576         setPrevName("");
 577
 578     if (curr != 0)
 579         setCurrName(curr->name);
 580     else{
 581         setCurrName("");
 582         SG_LOG(SG_GENERAL, SG_ALERT, "AIShip: current wp name error" );
 583     }
 584
 585     if (next != 0)
 586         setNextName(next->name);
 587     else
 588         setNextName("");
 589
 590     SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: prev wp name " << prev->name);
 591     SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: current wp name " << curr->name);
 592     SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: next wp name " << next->name);
 593
 594 }
 595
 596 double FGAIShip::getRange(double lat, double lon, double lat2, double lon2) const {
 597
 598     double course, distance, az2;
 599
 600     //calculate the bearing and range of the second pos from the first
 601     geo_inverse_wgs_84(lat, lon, lat2, lon2, &course, &az2, &distance);
 602     distance *= SG_METER_TO_NM;
 603     return distance;
 604 }
 605
 606 double FGAIShip::getCourse(double lat, double lon, double lat2, double lon2) const {
 607
 608     double course, distance, recip;
 609
 610     //calculate the bearing and range of the second pos from the first
 611     geo_inverse_wgs_84(lat, lon, lat2, lon2, &course, &recip, &distance);
 612     if (tgt_speed >= 0) {
 613         return course;
 614         SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: course " << course);
 615     } else {
 616         return recip;
 617         SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: recip " << recip);
 618     }
 619 }
 620
 621 void FGAIShip::ProcessFlightPlan(double dt) {
 622
 623     double time_sec = getDaySeconds();
 624
 625     _dt_count += dt;
 626
 627     ///////////////////////////////////////////////////////////////////////////
 628     // Check Execution time (currently once every 1 sec)
 629     // Add a bit of randomization to prevent the execution of all flight plans
 630     // in synchrony, which can add significant periodic framerate flutter.
 631     ///////////////////////////////////////////////////////////////////////////
 632
 633     //cout << "_start_sec " << _start_sec << " time_sec " << time_sec << endl;
 634     if (_dt_count < _next_run && _start_sec < time_sec)
 635         return;
 636
 637     _next_run = 0.05 + (0.025 * sg_random());
 638
 639     double until_time_sec = 0;
 640     _missed = false;
 641
 642     // check to see if we've reached the point for our next turn
 643     // if the range to the waypoint is less than the calculated turn
 644     // radius we can start the turn to the next leg
 645     _wp_range = getRange(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr->latitude, curr->longitude);
 646     _range_rate = (_wp_range - _old_range) / _dt_count;
 647     double sp_turn_radius_nm = _sp_turn_radius_ft / 6076.1155;
 648     // we need to try to identify a _missed waypoint
 649
 650     // calculate the time needed to turn through an arc of 90 degrees,
 651     // and allow a time error
 652     if (speed != 0)
 653         _missed_time_sec = 10 + ((SGD_PI * sp_turn_radius_nm * 60 * 60) / (2 * fabs(speed)));
 654     else
 655         _missed_time_sec = 10;
 656
 657     _missed_range = 4 * sp_turn_radius_nm;
 658
 659     //cout << _name << " range_rate " << _range_rate << " " << _new_waypoint<< endl ;
 660     //if ((_range_rate > 0) && !_new_waypoint){
 661     if (_range_rate > 0 && _wp_range < _missed_range && !_new_waypoint){
 662         _missed_count += _dt_count;
 663     }
 664
 665     if (_missed_count >= 120)
 666         setMissed(true);
 667     else if (_missed_count >= _missed_time_sec)
 668         setMissed(true);
 669     else
 670         setMissed(false);
 671
 672     _old_range = _wp_range;
 673     setWPNames();
 674
 675     if ((_wp_range < (sp_turn_radius_nm * 1.25)) || _missed || (_waiting && !_new_waypoint)) {
 676
 677         if (_next_name == "TUNNEL"){
 678             _tunnel = !_tunnel;
 679
 680             SG_LOG(SG_GENERAL, SG_ALERT, "AIShip: " << _name << " " << sp_turn_radius_nm );
 681
 682             fp->IncrementWaypoint(false);
 683             next = fp->getNextWaypoint();
 684
 685             if (next->name == "WAITUNTIL" || next->name == "WAIT"
 686                 || next->name == "END" || next->name == "TUNNEL")
 687                 return;
 688
 689             prev = curr;
 690             fp->IncrementWaypoint(false);
 691             curr = fp->getCurrentWaypoint();
 692             next = fp->getNextWaypoint();
 693
 694         }else if(_next_name == "END" || fp->getNextWaypoint() == 0) {
 695
 696             if (_repeat) {
 697                 SG_LOG(SG_GENERAL, SG_ALERT, "AIShip: "<< _name << " Flightplan repeating ");
 698                 fp->restart();
 699                 prev = curr;
 700                 curr = fp->getCurrentWaypoint();
 701                 next = fp->getNextWaypoint();
 702                 setWPNames();
 703                 _wp_range = getRange(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr->latitude, curr->longitude);
 704                 _old_range = _wp_range;
 705                 _range_rate = 0;
 706                 _new_waypoint = true;
 707                 _missed_count = 0;
 708                 _lead_angle = 0;
 709                 AccelTo(prev->speed);
 710             } else if (_restart){
 711                 SG_LOG(SG_GENERAL, SG_ALERT, "AIShip: " << _name << " Flightplan restarting ");
 712                 _missed_count = 0;
 713                 initFlightPlan();
 714             } else {
 715                 SG_LOG(SG_GENERAL, SG_ALERT, "AIShip: " << _name << " Flightplan dying ");
 716                 setDie(true);
 717                 _dt_count = 0;
 718                 return;
 719             }
 720
 721         } else if (_next_name == "WAIT") {
 722
 723             if (_wait_count < next->time_sec) {
 724                 SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: " << _name << " waiting ");
 725                 setSpeed(0);
 726                 _waiting = true;
 727                 _wait_count += _dt_count;
 728                 _dt_count = 0;
 729                 _lead_angle = 0;
 730                 return;
 731             } else {
 732                 SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: " << _name
 733                     << " wait done: getting new waypoints ");
 734                 _waiting = false;
 735                 _wait_count = 0;
 736                 fp->IncrementWaypoint(false);
 737                 next = fp->getNextWaypoint();
 738
 739                 if (next->name == "WAITUNTIL" || next->name == "WAIT"
 740                     || next->name == "END" || next->name == "TUNNEL")
 741                     return;
 742
 743                 prev = curr;
 744                 fp->IncrementWaypoint(false);
 745                 curr = fp->getCurrentWaypoint();
 746                 next = fp->getNextWaypoint();
 747             }
 748
 749         } else if (_next_name == "WAITUNTIL") {
 750             time_sec = getDaySeconds();
 751             until_time_sec = processTimeString(next->time);
 752             _until_time = next->time;
 753             setUntilTime(next->time);
 754             if (until_time_sec > time_sec) {
 755                 SG_LOG(SG_GENERAL, SG_ALERT, "AIShip: " << _name << " "
 756                     << curr->name << " waiting until: "
 757                     << _until_time << " " << until_time_sec << " now " << time_sec );
 758                 setSpeed(0);
 759                 _lead_angle = 0;
 760                 _waiting = true;
 761                 return;
 762             } else {
 763                 SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: "
 764                     << _name << " wait until done: getting new waypoints ");
 765                 setUntilTime("");
 766                 fp->IncrementWaypoint(false);
 767
 768                 while (next->name == "WAITUNTIL") {
 769                     fp->IncrementWaypoint(false);
 770                     next = fp->getNextWaypoint();
 771                 }
 772
 773                 if (next->name == "WAIT")
 774                     return;
 775
 776                 prev = curr;
 777                 fp->IncrementWaypoint(false);
 778                 curr = fp->getCurrentWaypoint();
 779                 next = fp->getNextWaypoint();
 780                 _waiting = false;
 781             }
 782
 783         } else {
 784             //now reorganise the waypoints, so that next becomes current and so on
 785             SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: " << _name << " getting new waypoints ");
 786             fp->IncrementWaypoint(false);
 787             prev = fp->getPreviousWaypoint(); //first waypoint
 788             curr = fp->getCurrentWaypoint();  //second waypoint
 789             next = fp->getNextWaypoint();     //third waypoint (might not exist!)
 790         }
 791
 792         setWPNames();
 793         _new_waypoint = true;
 794         _missed_count = 0;
 795         _range_rate = 0;
 796         _lead_angle = 0;
 797         _wp_range = getRange(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr->latitude, curr->longitude);
 798         _old_range = _wp_range;
 799         setWPPos();
 800         object_type type = getType();
 801
 802         if (type != 10)
 803             AccelTo(prev->speed);
 804
 805         _curr_alt = curr->altitude;
 806         _prev_alt = prev->altitude;
 807
 808     } else {
 809         _new_waypoint = false;
 810     }
 811
 812     //   now revise the required course for the next way point
 813     _course = getCourse(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr->latitude, curr->longitude);
 814
 815     if (finite(_course))
 816         TurnTo(_course);
 817     else
 818         SG_LOG(SG_GENERAL, SG_ALERT, "AIShip: Bearing or Range is not a finite number");
 819
 820     _dt_count = 0;
 821 } // end Processing FlightPlan
 822
 823 bool FGAIShip::initFlightPlan() {
 824
 825     SG_LOG(SG_GENERAL, SG_ALERT, "AIShip: " << _name << " initializing waypoints ");
 826
 827     bool init = false;
 828     _start_sec = 0;
 829     _tunnel = _initial_tunnel;
 830
 831     fp->restart();
 832     fp->IncrementWaypoint(false);
 833
 834     prev = fp->getPreviousWaypoint(); //first waypoint
 835     curr = fp->getCurrentWaypoint();  //second waypoint
 836     next = fp->getNextWaypoint();     //third waypoint (might not exist!)
 837
 838     while (curr->name == "WAIT" || curr->name == "WAITUNTIL") {  // don't wait when initialising
 839         SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: " << _name << " re-initializing waypoints ");
 840         fp->IncrementWaypoint(false);
 841         curr = fp->getCurrentWaypoint();
 842         next = fp->getNextWaypoint();
 843     } // end while loop
 844
 845     if (!_start_time.empty()){
 846         _start_sec = processTimeString(_start_time);
 847         double day_sec = getDaySeconds();
 848
 849         if (_start_sec < day_sec){
 850             //cout << "flight plan has already started " << _start_time << endl;
 851             init = advanceFlightPlan(_start_sec, day_sec);
 852
 853         } else if (_start_sec > day_sec && _repeat) {
 854             //cout << "flight plan has not started, " << _start_time;
 855             //cout << "offsetting start time by -24 hrs" << endl;
 856             _start_sec -= _day;
 857             init = advanceFlightPlan(_start_sec, day_sec);
 858         }
 859
 860         if (init)
 861             _start_sec = 0; // set to zero for an immediate start of the Flight Plan
 862         else {
 863             fp->restart();
 864             fp->IncrementWaypoint(false);
 865             prev = fp->getPreviousWaypoint();
 866             curr = fp->getCurrentWaypoint();
 867             next = fp->getNextWaypoint();
 868             return false;
 869         }
 870
 871     } else {
 872         setLatitude(prev->latitude);
 873         setLongitude(prev->longitude);
 874         setSpeed(prev->speed);
 875     }
 876
 877     setWPNames();
 878     setHeading(getCourse(prev->latitude, prev->longitude, curr->latitude, curr->longitude));
 879     _wp_range = getRange(prev->latitude, prev->longitude, curr->latitude, curr->longitude);
 880     _old_range = _wp_range;
 881     _range_rate = 0;
 882     _hdg_lock = true;
 883     _missed = false;
 884     _missed_count = 0;
 885     _new_waypoint = true;
 886
 887     SG_LOG(SG_GENERAL, SG_ALERT, "AIShip: " << _name << " done initialising waypoints " << _tunnel);
 888     if (prev)
 889         init = true;
 890
 891     if (init)
 892         return true;
 893     else
 894         return false;
 895
 896 } // end of initialization
 897
 898
 899 double FGAIShip::processTimeString(const string& theTime) {
 900
 901     int Hour;
 902     int Minute;
 903     int Second;
 904
 905     // first split theTime string into
 906     //  hour, minute, second and convert to int;
 907     Hour   = atoi(theTime.substr(0,2).c_str());
 908     Minute = atoi(theTime.substr(3,5).c_str());
 909     Second = atoi(theTime.substr(6,8).c_str());
 910
 911     // offset by a day-sec to allow for starting a day earlier
 912     double time_seconds = Hour * 3600
 913         + Minute * 60
 914         + Second;
 915
 916     return time_seconds;
 917 }
 918
 919 double FGAIShip::getDaySeconds () {
 920     // Date and time
 921     struct tm *t = globals->get_time_params()->getGmt();
 922
 923     double day_seconds = t->tm_hour * 3600
 924         + t->tm_min * 60
 925         + t->tm_sec;
 926
 927     return day_seconds;
 928 }
 929
 930 bool FGAIShip::advanceFlightPlan (double start_sec, double day_sec) {
 931
 932     double elapsed_sec = start_sec;
 933     double distance_nm = 0;
 934
 935     //cout << "advancing flight plan start_sec: " << start_sec << " " << day_sec << endl;
 936
 937     while ( elapsed_sec < day_sec ) {
 938
 939         if (next->name == "END" || fp->getNextWaypoint() == 0) {
 940
 941             if (_repeat ) {
 942                 //cout << _name << ": " << "restarting flightplan" << endl;
 943                 fp->restart();
 944                 curr = fp->getCurrentWaypoint();
 945                 next = fp->getNextWaypoint();
 946             } else {
 947                 //cout << _name << ": " << "ending flightplan" << endl;
 948                 setDie(true);
 949                 return false;
 950             }
 951
 952         } else if (next->name == "WAIT") {
 953             //cout << _name << ": begin WAIT: " << prev->name << " ";
 954             //cout << curr->name << " " << next->name << endl;
 955
 956             elapsed_sec += next->time_sec;
 957
 958             if ( elapsed_sec >= day_sec)
 959                 continue;
 960
 961             fp->IncrementWaypoint(false);
 962             next = fp->getNextWaypoint();
 963
 964             if (next->name != "WAITUNTIL" && next->name != "WAIT"
 965                 && next->name != "END") {
 966                     prev = curr;
 967                     fp->IncrementWaypoint(false);
 968                     curr = fp->getCurrentWaypoint();
 969                     next = fp->getNextWaypoint();
 970             }
 971
 972         } else if (next->name == "WAITUNTIL") {
 973             double until_sec = processTimeString(next->time);
 974
 975             if (until_sec > _start_sec && start_sec < 0)
 976                 until_sec -= _day;
 977
 978             if (elapsed_sec < until_sec)
 979                 elapsed_sec = until_sec;
 980
 981             if (elapsed_sec >= day_sec )
 982                 break;
 983
 984             fp->IncrementWaypoint(false);
 985             next = fp->getNextWaypoint();
 986
 987             if (next->name != "WAITUNTIL" && next->name != "WAIT") {
 988                 prev = curr;
 989                 fp->IncrementWaypoint(false);
 990                 curr = fp->getCurrentWaypoint();
 991                 next = fp->getNextWaypoint();
 992             }
 993
 994             //cout << _name << ": end WAITUNTIL: ";
 995             //cout << prev->name << " " << curr->name << " " << next->name <<  endl;
 996
 997         } else {
 998             distance_nm = getRange(prev->latitude, prev->longitude, curr->latitude, curr->longitude);
 999             elapsed_sec += distance_nm * 60 * 60 / prev->speed;
1000
1001             if (elapsed_sec >= day_sec)
1002                 continue;
1003
1004             fp->IncrementWaypoint(false);
1005             prev = fp->getPreviousWaypoint();
1006             curr = fp->getCurrentWaypoint();
1007             next = fp->getNextWaypoint();
1008         }
1009
1010     }   // end while
1011
1012     // the required position lies between the previous and current waypoints
1013     // so we will calculate the distance back up the track from the current waypoint
1014     // then calculate the lat and lon.
1015
1016     //cout << "advancing flight plan done elapsed_sec: " << elapsed_sec
1017     //    << " " << day_sec << endl;
1018
1019     double time_diff = elapsed_sec - day_sec;
1020     double lat, lon, recip;
1021
1022     //cout << " time diff " << time_diff << endl;
1023
1024     if (next->name == "WAIT" ){
1025         setSpeed(0);
1026         lat = curr->latitude;
1027         lon = curr->longitude;
1028         _wait_count= time_diff;
1029         _waiting = true;
1030     } else if (next->name == "WAITUNTIL") {
1031         setSpeed(0);
1032         lat = curr->latitude;
1033         lon = curr->longitude;
1034         _waiting = true;
1035     } else {
1036         setSpeed(prev->speed);
1037         distance_nm = speed * time_diff / (60 * 60);
1038         double brg = getCourse(curr->latitude, curr->longitude, prev->latitude, prev->longitude);
1039
1040         //cout << " brg " << brg << " from " << curr->name << " to " << prev->name << " "
1041         //    << " lat "  << curr->latitude << " lon " << curr->longitude
1042         //    << " distance m " << distance_nm * SG_NM_TO_METER << endl;
1043
1044         lat = geo_direct_wgs_84 (curr->latitude, curr->longitude, brg,
1045             distance_nm * SG_NM_TO_METER, &lat, &lon, &recip );
1046         lon = geo_direct_wgs_84 (curr->latitude, curr->longitude, brg,
1047             distance_nm * SG_NM_TO_METER, &lat, &lon, &recip );
1048         recip = geo_direct_wgs_84 (curr->latitude, curr->longitude, brg,
1049             distance_nm * SG_NM_TO_METER, &lat, &lon, &recip );
1050     }
1051
1052     setLatitude(lat);
1053     setLongitude(lon);
1054
1055     return true;
1056 }
1057
1058 void FGAIShip::setWPPos() {
1059
1060     if (curr->name == "END" || curr->name == "WAIT"
1061         || curr->name == "WAITUNTIL" || curr->name == "TUNNEL"){
1062             //cout << curr->name << " returning" << endl;
1063             return;
1064     }
1065
1066     double elevation_m = 0;
1067     wppos.setLatitudeDeg(curr->latitude);
1068     wppos.setLongitudeDeg(curr->longitude);
1069     wppos.setElevationM(0);
1070
1071     if (curr->on_ground){
1072
1073         if (globals->get_scenery()->get_elevation_m(SGGeod::fromGeodM(wppos, 3000),
1074             elevation_m, &_material, 0)){
1075                 wppos.setElevationM(elevation_m);
1076         }
1077
1078         //cout << curr->name << " setting measured  elev " << elevation_m << endl;
1079
1080     } else {
1081         wppos.setElevationM(curr->altitude);
1082         //cout << curr->name << " setting FP elev " << elevation_m << endl;
1083     }
1084
1085     curr->altitude = wppos.getElevationM();
1086
1087 }
1088
1089 void FGAIShip::setXTrackError() {
1090
1091     double course = getCourse(prev->latitude, prev->longitude,
1092         curr->latitude, curr->longitude);
1093     double brg = getCourse(pos.getLatitudeDeg(), pos.getLongitudeDeg(),
1094         curr->latitude, curr->longitude);
1095     double xtrack_error_nm = sin((course - brg)* SG_DEGREES_TO_RADIANS) * _wp_range;
1096     double factor = -0.0045 * speed + 1;
1097     double limit = _lead_angle_limit * factor;
1098
1099     if (_wp_range > 0){
1100         _lead_angle = atan2(xtrack_error_nm,(_wp_range * _proportion)) * SG_RADIANS_TO_DEGREES;
1101     } else
1102         _lead_angle = 0;
1103
1104     _lead_angle *= _lead_angle_gain * factor;
1105     _xtrack_error = xtrack_error_nm * 6076.1155;
1106
1107     SG_CLAMP_RANGE(_lead_angle, -limit, limit);
1108
1109 }