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 #include <cmath>
  25
  26 #ifdef _MSC_VER
  27 #  include <float.h>
  28     double fgIsFinite(double x) { return _finite(x); }
  29 #else
  30     double fgIsFinite(double x) { return std::isfinite(x); }
  31 #endif
  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 using std::string;
  44
  45 FGAIShip::FGAIShip(object_type ot) :
  46 // allow HOT to be enabled
  47 FGAIBase(ot, true),
  48
  49
  50 _waiting(false),
  51 _new_waypoint(true),
  52 _tunnel(false),
  53 _initial_tunnel(false),
  54 _restart(false),
  55 _hdg_constant(0.01),
  56 _limit(100),
  57 _elevation_m(0),
  58 _elevation_ft(0),
  59 _tow_angle(0),
  60 _missed_count(0),
  61 _wp_range(0),
  62 _dt_count(0),
  63 _next_run(0),
  64 _roll_constant(0.001),
  65 _roll_factor(-0.0083335),
  66 _old_range(0),
  67 _range_rate(0),
  68 _missed_time_sec(30),
  69 _day(86400),
  70 _lead_angle(0),
  71 _xtrack_error(0),
  72 _curr_alt(0),
  73 _prev_alt(0),
  74 _until_time(""),
  75 _fp_init(false),
  76 _missed(false)
  77 {
  78         invisible = false;
  79 }
  80
  81 FGAIShip::~FGAIShip() {
  82 }
  83
  84 void FGAIShip::readFromScenario(SGPropertyNode* scFileNode) {
  85
  86     if (!scFileNode)
  87         return;
  88
  89     FGAIBase::readFromScenario(scFileNode);
  90
  91     setRudder(scFileNode->getFloatValue("rudder", 0.0));
  92     setName(scFileNode->getStringValue("name", "Titanic"));
  93     setRadius(scFileNode->getDoubleValue("turn-radius-ft", 2000));
  94     const std::string& flightplan = scFileNode->getStringValue("flightplan");
  95     setRepeat(scFileNode->getBoolValue("repeat", false));
  96     setRestart(scFileNode->getBoolValue("restart", false));
  97     setStartTime(scFileNode->getStringValue("time", ""));
  98     setLeadAngleGain(scFileNode->getDoubleValue("lead-angle-gain", 1.5));
  99     setLeadAngleLimit(scFileNode->getDoubleValue("lead-angle-limit-deg", 15));
 100     setLeadAngleProp(scFileNode->getDoubleValue("lead-angle-proportion", 0.75));
 101     setRudderConstant(scFileNode->getDoubleValue("rudder-constant", 0.5));
 102     setFixedTurnRadius(scFileNode->getDoubleValue("fixed-turn-radius-ft", 500));
 103     setSpeedConstant(scFileNode->getDoubleValue("speed-constant", 0.5));
 104     setSMPath(scFileNode->getStringValue("submodel-path", ""));
 105     setRollFactor(scFileNode->getDoubleValue("roll-factor", 1));
 106
 107     if (!flightplan.empty()) {
 108         SG_LOG(SG_AI, SG_ALERT, "getting flightplan: " << _name );
 109
 110         FGAIFlightPlan* fp = new FGAIFlightPlan(flightplan);
 111         setFlightPlan(fp);
 112     }
 113
 114 }
 115
 116 bool FGAIShip::init(bool search_in_AI_path) {
 117     reinit();
 118     return FGAIBase::init(search_in_AI_path);
 119 }
 120
 121 void FGAIShip::reinit()
 122 {
 123     prev = 0; // the one behind you
 124     curr = 0; // the one ahead
 125     next = 0; // the next plus 1
 126
 127     props->setStringValue("name", _name.c_str());
 128     props->setStringValue("waypoint/name-prev", _prev_name.c_str());
 129     props->setStringValue("waypoint/name-curr", _curr_name.c_str());
 130     props->setStringValue("waypoint/name-next", _next_name.c_str());
 131     props->setStringValue("submodels/path", _path.c_str());
 132     props->setStringValue("waypoint/start-time", _start_time.c_str());
 133     props->setStringValue("waypoint/wait-until-time", _until_time.c_str());
 134
 135     _hdg_lock = false;
 136     _rudder = 0.0;
 137     no_roll = false;
 138
 139     _rd_turn_radius_ft = _sp_turn_radius_ft = turn_radius_ft;
 140
 141     if (fp)
 142         _fp_init = initFlightPlan();
 143
 144     FGAIBase::reinit();
 145 }
 146
 147 void FGAIShip::bind() {
 148     FGAIBase::bind();
 149
 150     tie("surface-positions/rudder-pos-deg",
 151         SGRawValuePointer<float>(&_rudder));
 152     tie("controls/heading-lock",
 153         SGRawValuePointer<bool>(&_hdg_lock));
 154     tie("controls/tgt-speed-kts",
 155         SGRawValuePointer<double>(&tgt_speed));
 156     tie("controls/tgt-heading-degs",
 157         SGRawValuePointer<double>(&tgt_heading));
 158     tie("controls/constants/roll-factor",
 159         SGRawValuePointer<double>(&_roll_factor));
 160     tie("controls/constants/roll",
 161         SGRawValuePointer<double>(&_roll_constant));
 162     tie("controls/constants/rudder",
 163         SGRawValuePointer<double>(&_rudder_constant));
 164     tie("controls/constants/speed",
 165         SGRawValuePointer<double>(&_speed_constant));
 166     tie("waypoint/range-nm",
 167         SGRawValuePointer<double>(&_wp_range));
 168     tie("waypoint/brg-deg",
 169         SGRawValuePointer<double>(&_course));
 170     tie("waypoint/rangerate-nm-sec",
 171         SGRawValuePointer<double>(&_range_rate));
 172     tie("waypoint/new",
 173         SGRawValuePointer<bool>(&_new_waypoint));
 174     tie("waypoint/missed",
 175         SGRawValuePointer<bool>(&_missed));
 176     tie("waypoint/missed-count-sec",
 177         SGRawValuePointer<double>(&_missed_count));
 178     tie("waypoint/missed-range-nm",
 179         SGRawValuePointer<double>(&_missed_range));
 180     tie("waypoint/missed-time-sec",
 181         SGRawValuePointer<double>(&_missed_time_sec));
 182     tie("waypoint/wait-count-sec",
 183         SGRawValuePointer<double>(&_wait_count));
 184     tie("waypoint/xtrack-error-ft",
 185         SGRawValuePointer<double>(&_xtrack_error));
 186     tie("waypoint/waiting",
 187         SGRawValuePointer<bool>(&_waiting));
 188     tie("waypoint/lead-angle-deg",
 189         SGRawValuePointer<double>(&_lead_angle));
 190     tie("waypoint/tunnel",
 191         SGRawValuePointer<bool>(&_tunnel));
 192     tie("waypoint/alt-curr-m",
 193         SGRawValuePointer<double>(&_curr_alt));
 194     tie("waypoint/alt-prev-m",
 195         SGRawValuePointer<double>(&_prev_alt));
 196     tie("submodels/serviceable",
 197         SGRawValuePointer<bool>(&_serviceable));
 198     tie("controls/turn-radius-ft",
 199         SGRawValuePointer<double>(&turn_radius_ft));
 200     tie("controls/turn-radius-corrected-ft",
 201         SGRawValuePointer<double>(&_rd_turn_radius_ft));
 202     tie("controls/constants/lead-angle/gain",
 203         SGRawValuePointer<double>(&_lead_angle_gain));
 204     tie("controls/constants/lead-angle/limit-deg",
 205         SGRawValuePointer<double>(&_lead_angle_limit));
 206     tie("controls/constants/lead-angle/proportion",
 207         SGRawValuePointer<double>(&_proportion));
 208     tie("controls/fixed-turn-radius-ft",
 209         SGRawValuePointer<double>(&_fixed_turn_radius));
 210     tie("controls/restart",
 211         SGRawValuePointer<bool>(&_restart));
 212     tie("velocities/speed-kts",
 213         SGRawValuePointer<double>(&speed));
 214 }
 215
 216 void FGAIShip::update(double dt) {
 217     //SG_LOG(SG_AI, SG_ALERT, "updating Ship: " << _name <<hdg<<pitch<<roll);
 218     // For computation of rotation speeds we just use finite differences here.
 219     // That is perfectly valid since this thing is not driven by accelerations
 220     // but by just apply discrete changes at its velocity variables.
 221     // Update the velocity information stored in those nodes.
 222     // Transform that one to the horizontal local coordinate system.
 223     SGQuatd ec2hl = SGQuatd::fromLonLat(pos);
 224     // The orientation of the ship wrt the horizontal local frame
 225     SGQuatd hl2body = SGQuatd::fromYawPitchRollDeg(hdg, pitch, roll);
 226     // and postrotate the orientation of the AIModel wrt the horizontal
 227     // local frame
 228     SGQuatd ec2body = ec2hl*hl2body;
 229     // The cartesian position of the ship in the wgs84 world
 230     //SGVec3d cartPos = SGVec3d::fromGeod(pos);
 231
 232     // The simulation time this transform is meant for
 233     aip.setReferenceTime(globals->get_sim_time_sec());
 234
 235     // Compute the velocity in m/s in the body frame
 236     aip.setBodyLinearVelocity(SGVec3d(0.51444444*speed, 0, 0));
 237
 238     FGAIBase::update(dt);
 239     Run(dt);
 240     Transform();
 241     if (fp)
 242         setXTrackError();
 243
 244     // Only change these values if we are able to compute them safely
 245     if (SGLimits<double>::min() < dt) {
 246         // Now here is the finite difference ...
 247
 248         // Transform that one to the horizontal local coordinate system.
 249         SGQuatd ec2hlNew = SGQuatd::fromLonLat(pos);
 250         // compute the new orientation
 251         SGQuatd hl2bodyNew = SGQuatd::fromYawPitchRollDeg(hdg, pitch, roll);
 252         // The rotation difference
 253         SGQuatd dOr = inverse(ec2body)*ec2hlNew*hl2bodyNew;
 254         SGVec3d dOrAngleAxis;
 255         dOr.getAngleAxis(dOrAngleAxis);
 256         // divided by the time difference provides a rotation speed vector
 257         dOrAngleAxis /= dt;
 258
 259         aip.setBodyAngularVelocity(dOrAngleAxis);
 260     }
 261 }
 262
 263 void FGAIShip::Run(double dt) {
 264     if (_fp_init)
 265         ProcessFlightPlan(dt);
 266
 267     const string& type = getTypeString();
 268
 269     double alpha;
 270     double rudder_limit;
 271     double raw_roll;
 272
 273     // adjust speed
 274     double speed_diff = tgt_speed - speed;
 275
 276     if (fabs(speed_diff) > 0.1) {
 277
 278         if (speed_diff > 0.0)
 279             speed += _speed_constant * dt;
 280
 281         if (speed_diff < 0.0)
 282             speed -= _speed_constant * dt;
 283
 284     }
 285
 286     // do not allow unreasonable speeds
 287     SG_CLAMP_RANGE(speed, -_limit * 0.75, _limit);
 288
 289     // convert speed to degrees per second
 290     speed_north_deg_sec = cos(hdg / SGD_RADIANS_TO_DEGREES)
 291         * speed * 1.686 / ft_per_deg_lat;
 292     speed_east_deg_sec = sin(hdg / SGD_RADIANS_TO_DEGREES)
 293         * speed * 1.686 / ft_per_deg_lon;
 294
 295     // set new position
 296     //cout << _name << " " << type << " run: " << _elevation_m << " " <<_elevation_ft << endl;
 297     pos.setLatitudeDeg(pos.getLatitudeDeg() + speed_north_deg_sec * dt);
 298     pos.setLongitudeDeg(pos.getLongitudeDeg() + speed_east_deg_sec * dt);
 299     pos.setElevationFt(tgt_altitude_ft);
 300     pitch = tgt_pitch;
 301
 302     // adjust heading based on current _rudder angle
 303     if (turn_radius_ft <= 0)
 304         turn_radius_ft = 0; // don't allow nonsense values
 305
 306     if (_rudder > 45)
 307         _rudder = 45;
 308
 309     if (_rudder < -45)
 310         _rudder = -45;
 311
 312
 313     //we assume that at slow speed ships will manoeuvre using engines/bow thruster
 314         if(type == "ship" || type == "carrier" || type == "escort"){
 315
 316                 if (fabs(speed)<=5)
 317                         _sp_turn_radius_ft = _fixed_turn_radius;
 318                 else {
 319                         // adjust turn radius for speed. The equation is very approximate.
 320                         // we need to allow for negative speeds
 321                         _sp_turn_radius_ft = 10 * pow ((fabs(speed) - 15), 2) + turn_radius_ft;
 322                 }
 323
 324         } else {
 325
 326                 if (fabs(speed) <= 40)
 327            _sp_turn_radius_ft = _fixed_turn_radius;
 328                 else {
 329                         // adjust turn radius for speed.
 330                         _sp_turn_radius_ft = turn_radius_ft;
 331                 }
 332         }
 333
 334
 335     if (_rudder <= -0.25 || _rudder >= 0.25) {
 336         // adjust turn radius for _rudder angle. The equation is even more approximate.
 337         float a = 19;
 338         float b = -0.2485;
 339         float c = 0.543;
 340
 341         _rd_turn_radius_ft = (a * exp(b * fabs(_rudder)) + c) * _sp_turn_radius_ft;
 342
 343         // calculate the angle, alpha, subtended by the arc traversed in time dt
 344         alpha = ((speed * 1.686 * dt) / _rd_turn_radius_ft) * SG_RADIANS_TO_DEGREES;
 345         //cout << _name << " alpha " << alpha << endl;
 346         // make sure that alpha is applied in the right direction
 347         hdg += alpha * sign(_rudder);
 348
 349         SG_NORMALIZE_RANGE(hdg, 0.0, 360.0);
 350
 351         //adjust roll for rudder angle and speed. Another bit of voodoo
 352         raw_roll = _roll_factor * speed * _rudder;
 353     } else {
 354         // _rudder angle is 0
 355         raw_roll = 0;
 356     }
 357
 358     //low pass filter
 359     if (speed < 0)
 360         roll = -roll;
 361
 362     roll = (raw_roll * _roll_constant) + (roll * (1 - _roll_constant));
 363
 364     // adjust target _rudder angle if heading lock engaged
 365     double rudder_diff = 0.0;
 366     if (_hdg_lock) {
 367         double rudder_sense = 0.0;
 368         double diff = fabs(hdg - tgt_heading);
 369         //cout << "_rudder diff" << diff << endl;
 370         if (diff > 180)
 371             diff = fabs(diff - 360);
 372
 373         double sum = hdg + diff;
 374
 375         if (sum > 360.0)
 376             sum -= 360.0;
 377
 378         if (fabs(sum - tgt_heading)< 1.0)
 379             rudder_sense = 1.0;
 380         else
 381             rudder_sense = -1.0;
 382
 383         if (speed < 0)
 384             rudder_sense = -rudder_sense;
 385
 386         if (diff < 15)
 387             _tgt_rudder = diff * rudder_sense;
 388         else
 389             _tgt_rudder = 45 * rudder_sense;
 390
 391         rudder_diff = _tgt_rudder - _rudder;
 392     }
 393
 394     // set the _rudder limit by speed
 395     if (type == "ship" || type == "carrier" || type == "escort"){
 396
 397         if (speed <= 40)
 398             rudder_limit = (-0.825 * speed) + 35;
 399         else
 400             rudder_limit = 2;
 401
 402     } else
 403         rudder_limit = 20;
 404
 405     if (fabs(rudder_diff)> 0.1) { // apply dead zone
 406
 407         if (rudder_diff > 0.0) {
 408             _rudder += _rudder_constant * dt;
 409
 410             if (_rudder > rudder_limit) // apply the _rudder limit
 411                 _rudder = rudder_limit;
 412
 413         } else if (rudder_diff < 0.0) {
 414             _rudder -= _rudder_constant * dt;
 415
 416             if (_rudder < -rudder_limit)
 417                 _rudder = -rudder_limit;
 418
 419         }
 420
 421         // do calculations for radar
 422         UpdateRadar(manager);
 423     }
 424 }//end function
 425
 426 void FGAIShip::AccelTo(double speed) {
 427     tgt_speed = speed;
 428 }
 429
 430 void FGAIShip::PitchTo(double angle) {
 431     tgt_pitch = angle;
 432 }
 433
 434 void FGAIShip::RollTo(double angle) {
 435     tgt_roll = angle;
 436 }
 437
 438 void FGAIShip::YawTo(double angle) {
 439 }
 440
 441 void FGAIShip::ClimbTo(double altitude) {
 442     tgt_altitude_ft = altitude;
 443     _setAltitude(altitude);
 444 }
 445
 446 void FGAIShip::TurnTo(double heading) {
 447     tgt_heading = heading - _lead_angle + _tow_angle;
 448     SG_NORMALIZE_RANGE(tgt_heading, 0.0, 360.0);
 449     _hdg_lock = true;
 450 }
 451
 452 double FGAIShip::sign(double x) {
 453     if (x < 0.0)
 454         return -1.0;
 455     else
 456         return 1.0;
 457 }
 458
 459 void FGAIShip::setFlightPlan(FGAIFlightPlan* f) {
 460     fp = f;
 461 }
 462
 463 void FGAIShip::setStartTime(const string& st) {
 464     _start_time = st;
 465 }
 466
 467 void FGAIShip::setUntilTime(const string& ut) {
 468     _until_time = ut;
 469     props->setStringValue("waypoint/wait-until-time", _until_time.c_str());
 470 }
 471
 472 void FGAIShip::setCurrName(const string& c) {
 473     _curr_name = c;
 474     props->setStringValue("waypoint/name-curr", _curr_name.c_str());
 475 }
 476
 477 void FGAIShip::setNextName(const string& n) {
 478     _next_name = n;
 479     props->setStringValue("waypoint/name-next", _next_name.c_str());
 480 }
 481
 482 void FGAIShip::setPrevName(const string& p) {
 483     _prev_name = p;
 484     props->setStringValue("waypoint/name-prev", _prev_name.c_str());
 485 }
 486
 487 void FGAIShip::setRepeat(bool r) {
 488     _repeat = r;
 489 }
 490
 491 void FGAIShip::setRestart(bool r) {
 492     _restart = r;
 493 }
 494
 495 void FGAIShip::setMissed(bool m) {
 496     _missed = m;
 497     props->setBoolValue("waypoint/missed", _missed);
 498 }
 499
 500 void FGAIShip::setRudder(float r) {
 501     _rudder = r;
 502 }
 503
 504 void FGAIShip::setRoll(double rl) {
 505     roll = rl;
 506 }
 507
 508 void FGAIShip::setLeadAngleGain(double g) {
 509     _lead_angle_gain = g;
 510 }
 511
 512 void FGAIShip::setLeadAngleLimit(double l) {
 513     _lead_angle_limit = l;
 514 }
 515
 516 void FGAIShip::setLeadAngleProp(double p) {
 517     _proportion = p;
 518 }
 519
 520 void FGAIShip::setRudderConstant(double rc) {
 521     _rudder_constant = rc;
 522 }
 523
 524 void FGAIShip::setSpeedConstant(double sc) {
 525     _speed_constant = sc;
 526 }
 527
 528 void FGAIShip::setFixedTurnRadius(double ftr) {
 529     _fixed_turn_radius = ftr;
 530 }
 531
 532 void FGAIShip::setRollFactor(double rf) {
 533     _roll_factor = rf * -0.0083335;
 534 }
 535
 536 void FGAIShip::setInitialTunnel(bool t) {
 537     _initial_tunnel = t;
 538     setTunnel(_initial_tunnel);
 539 }
 540
 541 void FGAIShip::setTunnel(bool t) {
 542     _tunnel = t;
 543 }
 544
 545 void FGAIShip::setWPNames() {
 546
 547     if (prev != 0)
 548         setPrevName(prev->getName());
 549     else
 550         setPrevName("");
 551
 552     if (curr != 0)
 553         setCurrName(curr->getName());
 554     else{
 555         setCurrName("");
 556         SG_LOG(SG_AI, SG_ALERT, "AIShip: current wp name error" );
 557     }
 558
 559     if (next != 0)
 560         setNextName(next->getName());
 561     else
 562         setNextName("");
 563
 564     SG_LOG(SG_AI, SG_DEBUG, "AIShip: prev wp name " << prev->getName());
 565     SG_LOG(SG_AI, SG_DEBUG, "AIShip: current wp name " << curr->getName());
 566     SG_LOG(SG_AI, SG_DEBUG, "AIShip: next wp name " << next->getName());
 567
 568 }
 569
 570 double FGAIShip::getRange(double lat, double lon, double lat2, double lon2) const {
 571
 572     double course, distance, az2;
 573
 574     //calculate the bearing and range of the second pos from the first
 575     geo_inverse_wgs_84(lat, lon, lat2, lon2, &course, &az2, &distance);
 576     distance *= SG_METER_TO_NM;
 577     return distance;
 578 }
 579
 580 double FGAIShip::getCourse(double lat, double lon, double lat2, double lon2) const {
 581
 582     double course, distance, recip;
 583
 584     //calculate the bearing and range of the second pos from the first
 585     geo_inverse_wgs_84(lat, lon, lat2, lon2, &course, &recip, &distance);
 586     if (tgt_speed >= 0) {
 587         return course;
 588         SG_LOG(SG_AI, SG_DEBUG, "AIShip: course " << course);
 589     } else {
 590         return recip;
 591         SG_LOG(SG_AI, SG_DEBUG, "AIShip: recip " << recip);
 592     }
 593 }
 594
 595 void FGAIShip::ProcessFlightPlan(double dt) {
 596
 597     if ( dt < 0.00001 ) {
 598         return;
 599     }
 600
 601     double time_sec = getDaySeconds();
 602
 603     _dt_count += dt;
 604
 605     ///////////////////////////////////////////////////////////////////////////
 606     // Check Execution time (currently once every 1 sec)
 607     // Add a bit of randomization to prevent the execution of all flight plans
 608     // in synchrony, which can add significant periodic framerate flutter.
 609     ///////////////////////////////////////////////////////////////////////////
 610
 611     //cout << "_start_sec " << _start_sec << " time_sec " << time_sec << endl;
 612     if (_dt_count < _next_run && _start_sec < time_sec)
 613         return;
 614
 615     _next_run = 0.05 + (0.025 * sg_random());
 616
 617     double until_time_sec = 0;
 618     _missed = false;
 619
 620     // check to see if we've reached the point for our next turn
 621     // if the range to the waypoint is less than the calculated turn
 622     // radius we can start the turn to the next leg
 623     _wp_range = getRange(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr->getLatitude(), curr->getLongitude());
 624     _range_rate = (_wp_range - _old_range) / _dt_count;
 625     double sp_turn_radius_nm = _sp_turn_radius_ft / 6076.1155;
 626     // we need to try to identify a _missed waypoint
 627
 628     // calculate the time needed to turn through an arc of 90 degrees,
 629     // and allow a time error
 630     if (speed != 0)
 631         _missed_time_sec = 10 + ((SGD_PI * sp_turn_radius_nm * 60 * 60) / (2 * fabs(speed)));
 632     else
 633         _missed_time_sec = 10;
 634
 635     _missed_range = 4 * sp_turn_radius_nm;
 636
 637     //cout << _name << " range_rate " << _range_rate << " " << _new_waypoint<< endl ;
 638     //if ((_range_rate > 0) && !_new_waypoint){
 639     if (_range_rate > 0 && _wp_range < _missed_range && !_new_waypoint){
 640         _missed_count += _dt_count;
 641     }
 642
 643     if (_missed_count >= 120)
 644         setMissed(true);
 645     else if (_missed_count >= _missed_time_sec)
 646         setMissed(true);
 647     else
 648         setMissed(false);
 649
 650     _old_range = _wp_range;
 651     setWPNames();
 652
 653     if ((_wp_range < (sp_turn_radius_nm * 1.25)) || _missed || (_waiting && !_new_waypoint)) {
 654
 655         if (_next_name == "TUNNEL"){
 656             _tunnel = !_tunnel;
 657
 658             SG_LOG(SG_AI, SG_DEBUG, "AIShip: " << _name << " " << sp_turn_radius_nm );
 659
 660             fp->IncrementWaypoint(false);
 661             next = fp->getNextWaypoint();
 662
 663             if (next->getName() == "WAITUNTIL" || next->getName() == "WAIT"
 664                 || next->getName() == "END" || next->getName() == "TUNNEL")
 665                 return;
 666
 667             prev = curr;
 668             fp->IncrementWaypoint(false);
 669             curr = fp->getCurrentWaypoint();
 670             next = fp->getNextWaypoint();
 671
 672         }else if(_next_name == "END" || fp->getNextWaypoint() == 0) {
 673
 674             if (_repeat) {
 675                 SG_LOG(SG_AI, SG_INFO, "AIShip: "<< _name << " Flightplan repeating ");
 676                 fp->restart();
 677                 prev = curr;
 678                 curr = fp->getCurrentWaypoint();
 679                 next = fp->getNextWaypoint();
 680                 setWPNames();
 681                 _wp_range = getRange(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr->getLatitude(), curr->getLongitude());
 682                 _old_range = _wp_range;
 683                 _range_rate = 0;
 684                 _new_waypoint = true;
 685                 _missed_count = 0;
 686                 _lead_angle = 0;
 687                 AccelTo(prev->getSpeed());
 688             } else if (_restart){
 689                 SG_LOG(SG_AI, SG_INFO, "AIShip: " << _name << " Flightplan restarting ");
 690                 _missed_count = 0;
 691                 initFlightPlan();
 692             } else {
 693                 SG_LOG(SG_AI, SG_ALERT, "AIShip: " << _name << " Flightplan dying ");
 694                 setDie(true);
 695                 _dt_count = 0;
 696                 return;
 697             }
 698
 699         } else if (_next_name == "WAIT") {
 700
 701             if (_wait_count < next->getTime_sec()) {
 702                 SG_LOG(SG_AI, SG_DEBUG, "AIShip: " << _name << " waiting ");
 703                 setSpeed(0);
 704                 _waiting = true;
 705                 _wait_count += _dt_count;
 706                 _dt_count = 0;
 707                 _lead_angle = 0;
 708                 return;
 709             } else {
 710                 SG_LOG(SG_AI, SG_DEBUG, "AIShip: " << _name
 711                     << " wait done: getting new waypoints ");
 712                 _waiting = false;
 713                 _wait_count = 0;
 714                 fp->IncrementWaypoint(false);
 715                 next = fp->getNextWaypoint();
 716
 717                 if (next->getName() == "WAITUNTIL" || next->getName() == "WAIT"
 718                     || next->getName() == "END" || next->getName() == "TUNNEL")
 719                     return;
 720
 721                 prev = curr;
 722                 fp->IncrementWaypoint(false);
 723                 curr = fp->getCurrentWaypoint();
 724                 next = fp->getNextWaypoint();
 725             }
 726
 727         } else if (_next_name == "WAITUNTIL") {
 728             time_sec = getDaySeconds();
 729             until_time_sec = processTimeString(next->getTime());
 730             _until_time = next->getTime();
 731             setUntilTime(next->getTime());
 732             if (until_time_sec > time_sec) {
 733                 SG_LOG(SG_AI, SG_INFO, "AIShip: " << _name << " "
 734                     << curr->getName() << " waiting until: "
 735                     << _until_time << " " << until_time_sec << " now " << time_sec );
 736                 setSpeed(0);
 737                 _lead_angle = 0;
 738                 _waiting = true;
 739                 return;
 740             } else {
 741                 SG_LOG(SG_AI, SG_INFO, "AIShip: "
 742                     << _name << " wait until done: getting new waypoints ");
 743                 setUntilTime("");
 744                 fp->IncrementWaypoint(false);
 745
 746                 while (next->getName() == "WAITUNTIL") {
 747                     fp->IncrementWaypoint(false);
 748                     next = fp->getNextWaypoint();
 749                 }
 750
 751                 if (next->getName() == "WAIT")
 752                     return;
 753
 754                 prev = curr;
 755                 fp->IncrementWaypoint(false);
 756                 curr = fp->getCurrentWaypoint();
 757                 next = fp->getNextWaypoint();
 758                 _waiting = false;
 759             }
 760
 761         } else {
 762             //now reorganise the waypoints, so that next becomes current and so on
 763             SG_LOG(SG_AI, SG_DEBUG, "AIShip: " << _name << " getting new waypoints ");
 764             fp->IncrementWaypoint(false);
 765             prev = fp->getPreviousWaypoint(); //first waypoint
 766             curr = fp->getCurrentWaypoint();  //second waypoint
 767             next = fp->getNextWaypoint();     //third waypoint (might not exist!)
 768         }
 769
 770         setWPNames();
 771         _new_waypoint = true;
 772         _missed_count = 0;
 773         _range_rate = 0;
 774         _lead_angle = 0;
 775         _wp_range = getRange(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr->getLatitude(), curr->getLongitude());
 776         _old_range = _wp_range;
 777         setWPPos();
 778         object_type type = getType();
 779
 780         if (type != 10)
 781             AccelTo(prev->getSpeed());
 782
 783         _curr_alt = curr->getAltitude();
 784         _prev_alt = prev->getAltitude();
 785
 786     } else {
 787         _new_waypoint = false;
 788     }
 789
 790     //   now revise the required course for the next way point
 791     _course = getCourse(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr->getLatitude(), curr->getLongitude());
 792
 793     if (fgIsFinite(_course))
 794         TurnTo(_course);
 795     else
 796         SG_LOG(SG_AI, SG_ALERT, "AIShip: Bearing or Range is not a finite number");
 797
 798     _dt_count = 0;
 799 } // end Processing FlightPlan
 800
 801 bool FGAIShip::initFlightPlan() {
 802
 803     SG_LOG(SG_AI, SG_ALERT, "AIShip: " << _name << " initializing waypoints ");
 804
 805     bool init = false;
 806     _start_sec = 0;
 807     _tunnel = _initial_tunnel;
 808
 809     fp->restart();
 810     fp->IncrementWaypoint(false);
 811
 812     prev = fp->getPreviousWaypoint(); //first waypoint
 813     curr = fp->getCurrentWaypoint();  //second waypoint
 814     next = fp->getNextWaypoint();     //third waypoint (might not exist!)
 815
 816     while (curr->getName() == "WAIT" || curr->getName() == "WAITUNTIL") {  // don't wait when initialising
 817         SG_LOG(SG_AI, SG_DEBUG, "AIShip: " << _name << " re-initializing waypoints ");
 818         fp->IncrementWaypoint(false);
 819         curr = fp->getCurrentWaypoint();
 820         next = fp->getNextWaypoint();
 821     } // end while loop
 822
 823     if (!_start_time.empty()){
 824         _start_sec = processTimeString(_start_time);
 825         double day_sec = getDaySeconds();
 826
 827         if (_start_sec < day_sec){
 828             //cout << "flight plan has already started " << _start_time << endl;
 829             init = advanceFlightPlan(_start_sec, day_sec);
 830
 831         } else if (_start_sec > day_sec && _repeat) {
 832             //cout << "flight plan has not started, " << _start_time;
 833             //cout << "offsetting start time by -24 hrs" << endl;
 834             _start_sec -= _day;
 835             init = advanceFlightPlan(_start_sec, day_sec);
 836         }
 837
 838         if (init)
 839             _start_sec = 0; // set to zero for an immediate start of the Flight Plan
 840         else {
 841             fp->restart();
 842             fp->IncrementWaypoint(false);
 843             prev = fp->getPreviousWaypoint();
 844             curr = fp->getCurrentWaypoint();
 845             next = fp->getNextWaypoint();
 846             return false;
 847         }
 848
 849     } else {
 850         setLatitude(prev->getLatitude());
 851         setLongitude(prev->getLongitude());
 852         setSpeed(prev->getSpeed());
 853     }
 854
 855     setWPNames();
 856     setHeading(getCourse(prev->getLatitude(), prev->getLongitude(), curr->getLatitude(), curr->getLongitude()));
 857     _wp_range = getRange(prev->getLatitude(), prev->getLongitude(), curr->getLatitude(), curr->getLongitude());
 858     _old_range = _wp_range;
 859     _range_rate = 0;
 860     _hdg_lock = true;
 861     _missed = false;
 862     _missed_count = 0;
 863     _new_waypoint = true;
 864
 865     SG_LOG(SG_AI, SG_ALERT, "AIShip: " << _name << " done initialising waypoints " << _tunnel);
 866     if (prev)
 867         init = true;
 868
 869     if (init)
 870         return true;
 871     else
 872         return false;
 873
 874 } // end of initialization
 875
 876
 877 double FGAIShip::processTimeString(const string& theTime) {
 878
 879     int Hour;
 880     int Minute;
 881     int Second;
 882
 883     // first split theTime string into
 884     //  hour, minute, second and convert to int;
 885     Hour   = atoi(theTime.substr(0,2).c_str());
 886     Minute = atoi(theTime.substr(3,5).c_str());
 887     Second = atoi(theTime.substr(6,8).c_str());
 888
 889     // offset by a day-sec to allow for starting a day earlier
 890     double time_seconds = Hour * 3600
 891         + Minute * 60
 892         + Second;
 893
 894     return time_seconds;
 895 }
 896
 897 double FGAIShip::getDaySeconds () {
 898     // Date and time
 899     struct tm *t = globals->get_time_params()->getGmt();
 900
 901     double day_seconds = t->tm_hour * 3600
 902         + t->tm_min * 60
 903         + t->tm_sec;
 904
 905     return day_seconds;
 906 }
 907
 908 bool FGAIShip::advanceFlightPlan (double start_sec, double day_sec) {
 909
 910     double elapsed_sec = start_sec;
 911     double distance_nm = 0;
 912
 913     //cout << "advancing flight plan start_sec: " << start_sec << " " << day_sec << endl;
 914
 915     while ( elapsed_sec < day_sec ) {
 916
 917         if (next->getName() == "END" || fp->getNextWaypoint() == 0) {
 918
 919             if (_repeat ) {
 920                 //cout << _name << ": " << "restarting flightplan" << endl;
 921                 fp->restart();
 922                 curr = fp->getCurrentWaypoint();
 923                 next = fp->getNextWaypoint();
 924             } else {
 925                 //cout << _name << ": " << "ending flightplan" << endl;
 926                 setDie(true);
 927                 return false;
 928             }
 929
 930         } else if (next->getName() == "WAIT") {
 931             //cout << _name << ": begin WAIT: " << prev->name << " ";
 932             //cout << curr->name << " " << next->name << endl;
 933
 934             elapsed_sec += next->getTime_sec();
 935
 936             if ( elapsed_sec >= day_sec)
 937                 continue;
 938
 939             fp->IncrementWaypoint(false);
 940             next = fp->getNextWaypoint();
 941
 942             if (next->getName() != "WAITUNTIL" && next->getName() != "WAIT"
 943                 && next->getName() != "END") {
 944                     prev = curr;
 945                     fp->IncrementWaypoint(false);
 946                     curr = fp->getCurrentWaypoint();
 947                     next = fp->getNextWaypoint();
 948             }
 949
 950         } else if (next->getName() == "WAITUNTIL") {
 951             double until_sec = processTimeString(next->getTime());
 952
 953             if (until_sec > _start_sec && start_sec < 0)
 954                 until_sec -= _day;
 955
 956             if (elapsed_sec < until_sec)
 957                 elapsed_sec = until_sec;
 958
 959             if (elapsed_sec >= day_sec )
 960                 break;
 961
 962             fp->IncrementWaypoint(false);
 963             next = fp->getNextWaypoint();
 964
 965             if (next->getName() != "WAITUNTIL" && next->getName() != "WAIT") {
 966                 prev = curr;
 967                 fp->IncrementWaypoint(false);
 968                 curr = fp->getCurrentWaypoint();
 969                 next = fp->getNextWaypoint();
 970             }
 971
 972             //cout << _name << ": end WAITUNTIL: ";
 973             //cout << prev->name << " " << curr->name << " " << next->name <<  endl;
 974
 975         } else {
 976             distance_nm = getRange(prev->getLatitude(), prev->getLongitude(), curr->getLatitude(), curr->getLongitude());
 977             elapsed_sec += distance_nm * 60 * 60 / prev->getSpeed();
 978
 979             if (elapsed_sec >= day_sec)
 980                 continue;
 981
 982             fp->IncrementWaypoint(false);
 983             prev = fp->getPreviousWaypoint();
 984             curr = fp->getCurrentWaypoint();
 985             next = fp->getNextWaypoint();
 986         }
 987
 988     }   // end while
 989
 990     // the required position lies between the previous and current waypoints
 991     // so we will calculate the distance back up the track from the current waypoint
 992     // then calculate the lat and lon.
 993
 994     //cout << "advancing flight plan done elapsed_sec: " << elapsed_sec
 995     //    << " " << day_sec << endl;
 996
 997     double time_diff = elapsed_sec - day_sec;
 998     double lat, lon, recip;
 999
1000     //cout << " time diff " << time_diff << endl;
1001
1002     if (next->getName() == "WAIT" ){
1003         setSpeed(0);
1004         lat = curr->getLatitude();
1005         lon = curr->getLongitude();
1006         _wait_count= time_diff;
1007         _waiting = true;
1008     } else if (next->getName() == "WAITUNTIL") {
1009         setSpeed(0);
1010         lat = curr->getLatitude();
1011         lon = curr->getLongitude();
1012         _waiting = true;
1013     } else {
1014         setSpeed(prev->getSpeed());
1015         distance_nm = speed * time_diff / (60 * 60);
1016         double brg = getCourse(curr->getLatitude(), curr->getLongitude(), prev->getLatitude(), prev->getLongitude());
1017
1018         //cout << " brg " << brg << " from " << curr->name << " to " << prev->name << " "
1019         //    << " lat "  << curr->latitude << " lon " << curr->longitude
1020         //    << " distance m " << distance_nm * SG_NM_TO_METER << endl;
1021
1022         lat = geo_direct_wgs_84 (curr->getLatitude(), curr->getLongitude(), brg,
1023             distance_nm * SG_NM_TO_METER, &lat, &lon, &recip );
1024         lon = geo_direct_wgs_84 (curr->getLatitude(), curr->getLongitude(), brg,
1025             distance_nm * SG_NM_TO_METER, &lat, &lon, &recip );
1026         recip = geo_direct_wgs_84 (curr->getLatitude(), curr->getLongitude(), brg,
1027             distance_nm * SG_NM_TO_METER, &lat, &lon, &recip );
1028     }
1029
1030     setLatitude(lat);
1031     setLongitude(lon);
1032
1033     return true;
1034 }
1035
1036 void FGAIShip::setWPPos() {
1037
1038     if (curr->getName() == "END" || curr->getName() == "WAIT"
1039         || curr->getName() == "WAITUNTIL" || curr->getName() == "TUNNEL"){
1040             //cout << curr->name << " returning" << endl;
1041             return;
1042     }
1043
1044     double elevation_m = 0;
1045     wppos.setLatitudeDeg(curr->getLatitude());
1046     wppos.setLongitudeDeg(curr->getLongitude());
1047     wppos.setElevationM(0);
1048
1049     if (curr->getOn_ground()){
1050
1051         if (globals->get_scenery()->get_elevation_m(SGGeod::fromGeodM(wppos, 3000),
1052             elevation_m, NULL, 0)){
1053                 wppos.setElevationM(elevation_m);
1054         }
1055
1056         //cout << curr->name << " setting measured  elev " << elevation_m << endl;
1057
1058     } else {
1059         wppos.setElevationM(curr->getAltitude());
1060         //cout << curr->name << " setting FP elev " << elevation_m << endl;
1061     }
1062
1063     curr->setAltitude(wppos.getElevationM());
1064
1065 }
1066
1067 void FGAIShip::setXTrackError() {
1068
1069     double course = getCourse(prev->getLatitude(), prev->getLongitude(),
1070         curr->getLatitude(), curr->getLongitude());
1071     double brg = getCourse(pos.getLatitudeDeg(), pos.getLongitudeDeg(),
1072         curr->getLatitude(), curr->getLongitude());
1073     double xtrack_error_nm = sin((course - brg)* SG_DEGREES_TO_RADIANS) * _wp_range;
1074     double factor = -0.0045 * speed + 1;
1075     double limit = _lead_angle_limit * factor;
1076
1077     if (_wp_range > 0){
1078         _lead_angle = atan2(xtrack_error_nm,(_wp_range * _proportion)) * SG_RADIANS_TO_DEGREES;
1079     } else
1080         _lead_angle = 0;
1081
1082     _lead_angle *= _lead_angle_gain * factor;
1083     _xtrack_error = xtrack_error_nm * 6076.1155;
1084
1085     SG_CLAMP_RANGE(_lead_angle, -limit, limit);
1086
1087 }