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
  55 {
  56 }
  57
  58 FGAIShip::~FGAIShip() {
  59 }
  60
  61 void FGAIShip::readFromScenario(SGPropertyNode* scFileNode) {
  62
  63     if (!scFileNode)
  64         return;
  65
  66     FGAIBase::readFromScenario(scFileNode);
  67
  68     setRudder(scFileNode->getFloatValue("rudder", 0.0));
  69     setName(scFileNode->getStringValue("name", "Titanic"));
  70     setRadius(scFileNode->getDoubleValue("turn-radius-ft", 2000));
  71     std::string flightplan = scFileNode->getStringValue("flightplan");
  72     setRepeat(scFileNode->getBoolValue("repeat", false));
  73     setStartTime(scFileNode->getStringValue("time", ""));
  74     setLeadAngleGain(scFileNode->getDoubleValue("lead-angle-gain", 1.5));
  75     setLeadAngleLimit(scFileNode->getDoubleValue("lead-angle-limit-deg", 15));
  76     setLeadAngleProp(scFileNode->getDoubleValue("lead-angle-proportion", 0.75));
  77     setRudderConstant(scFileNode->getDoubleValue("rudder-constant", 0.5));
  78     setFixedTurnRadius(scFileNode->getDoubleValue("fixed-turn-radius-ft", 500));
  79     setSpeedConstant(scFileNode->getDoubleValue("speed-constant", 0.5));
  80
  81     if (!flightplan.empty()) {
  82             SG_LOG(SG_GENERAL, SG_ALERT, "getting flightplan: " << _name );
  83
  84         FGAIFlightPlan* fp = new FGAIFlightPlan(flightplan);
  85         setFlightPlan(fp);
  86     }
  87
  88 }
  89
  90 bool FGAIShip::init(bool search_in_AI_path) {
  91     prev = 0; // the one behind you
  92     curr = 0; // the one ahead
  93     next = 0; // the next plus 1
  94
  95     _until_time = "";
  96
  97     props->setStringValue("name", _name.c_str());
  98     props->setStringValue("waypoint/name-prev", _prev_name.c_str());
  99     props->setStringValue("waypoint/name-curr", _curr_name.c_str());
 100     props->setStringValue("waypoint/name-next", _next_name.c_str());
 101     props->setStringValue("submodels/path", _path.c_str());
 102     props->setStringValue("waypoint/start-time", _start_time.c_str());
 103     props->setStringValue("waypoint/wait-until-time", _until_time.c_str());
 104
 105     _hdg_lock = false;
 106     _rudder = 0.0;
 107     no_roll = false;
 108
 109     _roll_constant = 0.001;
 110     _hdg_constant = 0.01;
 111     _roll_factor = -0.0083335;
 112
 113     _rd_turn_radius_ft = _sp_turn_radius_ft = turn_radius_ft;
 114
 115     _fp_init = false;
 116     _missed = false;
 117     _waiting = false;
 118     _new_waypoint = true;
 119
 120     _missed_count = 0;
 121     _wait_count = 0;
 122     _missed_time_sec = 30;
 123
 124     _day = 86400;
 125
 126
 127     _wp_range = _old_range = 0;
 128     _range_rate = 0;
 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("submodels/serviceable",
 182         SGRawValuePointer<bool>(&_serviceable));
 183     props->tie("controls/turn-radius-ft",
 184         SGRawValuePointer<double>(&turn_radius_ft));
 185     props->tie("controls/turn-radius-corrected-ft",
 186         SGRawValuePointer<double>(&_rd_turn_radius_ft));
 187     props->tie("controls/constants/lead-angle/gain",
 188         SGRawValuePointer<double>(&_lead_angle_gain));
 189     props->tie("controls/constants/lead-angle/limit-deg",
 190         SGRawValuePointer<double>(&_lead_angle_limit));
 191     props->tie("controls/constants/lead-angle/proportion",
 192         SGRawValuePointer<double>(&_proportion));
 193     props->tie("controls/fixed-turn-radius-ft",
 194         SGRawValuePointer<double>(&_fixed_turn_radius));
 195 }
 196
 197 void FGAIShip::unbind() {
 198     FGAIBase::unbind();
 199     props->untie("surface-positions/rudder-pos-deg");
 200     props->untie("controls/heading-lock");
 201     props->untie("controls/tgt-speed-kts");
 202     props->untie("controls/tgt-heading-degs");
 203     props->untie("controls/constants/roll");
 204     props->untie("controls/constants/rudder");
 205     props->untie("controls/constants/roll-factor");
 206     props->untie("controls/constants/speed");
 207     props->untie("waypoint/range-nm");
 208     props->untie("waypoint/range-brg-deg");
 209     props->untie("waypoint/rangerate-nm-sec");
 210     props->untie("waypoint/new");
 211     props->untie("waypoint/missed");
 212     props->untie("waypoint/missed-count-sec");
 213     props->untie("waypoint/missed-time-sec");
 214     props->untie("waypoint/missed-range");
 215     props->untie("waypoint/wait-count-sec");
 216     props->untie("waypoint/lead-angle-deg");
 217     props->untie("waypoint/xtrack-error-ft");
 218     props->untie("waypoint/waiting");
 219     props->untie("submodels/serviceable");
 220     props->untie("controls/turn-radius-ft");
 221     props->untie("controls/turn-radius-corrected-ft");
 222     props->untie("controls/constants/lead-angle/gain");
 223     props->untie("controls/constants/lead-angle/limit-deg");
 224     props->untie("controls/constants/lead-angle/proportion");
 225     props->untie("controls/fixed-turn-radius-ft");
 226     props->untie("controls/constants/speed");
 227
 228 }
 229 void FGAIShip::update(double dt) {
 230     //SG_LOG(SG_GENERAL, SG_ALERT, "updating Ship: " << _name <<hdg<<pitch<<roll);
 231     // For computation of rotation speeds we just use finite differences here.
 232     // That is perfectly valid since this thing is not driven by accelerations
 233     // but by just apply discrete changes at its velocity variables.
 234     // Update the velocity information stored in those nodes.
 235     // Transform that one to the horizontal local coordinate system.
 236     SGQuatd ec2hl = SGQuatd::fromLonLat(pos);
 237     // The orientation of the carrier wrt the horizontal local frame
 238     SGQuatd hl2body = SGQuatd::fromYawPitchRollDeg(hdg, pitch, roll);
 239     // and postrotate the orientation of the AIModel wrt the horizontal
 240     // local frame
 241     SGQuatd ec2body = ec2hl*hl2body;
 242     // The cartesian position of the carrier in the wgs84 world
 243     SGVec3d cartPos = SGVec3d::fromGeod(pos);
 244
 245     // The simulation time this transform is meant for
 246     aip.setReferenceTime(globals->get_sim_time_sec());
 247
 248     // Compute the velocity in m/s in the body frame
 249     aip.setBodyLinearVelocity(SGVec3d(0.51444444*speed, 0, 0));
 250
 251     FGAIBase::update(dt);
 252     Run(dt);
 253     Transform();
 254     if (fp)
 255         setXTrackError();
 256
 257     // Only change these values if we are able to compute them safely
 258     if (SGLimits<double>::min() < dt) {
 259         // Now here is the finite difference ...
 260
 261         // Transform that one to the horizontal local coordinate system.
 262         SGQuatd ec2hlNew = SGQuatd::fromLonLat(pos);
 263         // compute the new orientation
 264         SGQuatd hl2bodyNew = SGQuatd::fromYawPitchRollDeg(hdg, pitch, roll);
 265         // The rotation difference
 266         SGQuatd dOr = inverse(ec2body)*ec2hlNew*hl2bodyNew;
 267         SGVec3d dOrAngleAxis;
 268         dOr.getAngleAxis(dOrAngleAxis);
 269         // divided by the time difference provides a rotation speed vector
 270         dOrAngleAxis /= dt;
 271
 272         aip.setBodyAngularVelocity(dOrAngleAxis);
 273     }
 274 }
 275
 276 void FGAIShip::Run(double dt) {
 277     if (_fp_init)
 278         ProcessFlightPlan(dt);
 279
 280     string type = getTypeString();
 281
 282     double alpha;
 283     double rudder_limit;
 284     double raw_roll;
 285
 286     // adjust speed
 287     double speed_diff = tgt_speed - speed;
 288
 289     if (fabs(speed_diff) > 0.1) {
 290
 291         if (speed_diff > 0.0)
 292             speed += _speed_constant * dt;
 293
 294         if (speed_diff < 0.0)
 295             speed -= _speed_constant * dt;
 296
 297     }
 298
 299     // do not allow unreasonable speeds
 300     if (speed > _limit)
 301         speed = _limit;
 302
 303     // convert speed to degrees per second
 304     speed_north_deg_sec = cos(hdg / SGD_RADIANS_TO_DEGREES)
 305         * speed * 1.686 / ft_per_deg_lat;
 306     speed_east_deg_sec = sin(hdg / SGD_RADIANS_TO_DEGREES)
 307         * speed * 1.686 / ft_per_deg_lon;
 308
 309     // set new position
 310     //cout << _name << " " << type << " run: " << _elevation_m << " " <<_elevation_ft << endl;
 311     pos.setLatitudeDeg(pos.getLatitudeDeg() + speed_north_deg_sec * dt);
 312     pos.setLongitudeDeg(pos.getLongitudeDeg() + speed_east_deg_sec * dt);
 313     pos.setElevationFt(tgt_altitude_ft);
 314     pitch = tgt_pitch;
 315
 316     // adjust heading based on current _rudder angle
 317     if (turn_radius_ft <= 0)
 318         turn_radius_ft = 0; // don't allow nonsense values
 319
 320     if (_rudder > 45)
 321         _rudder = 45;
 322
 323     if (_rudder < -45)
 324         _rudder = -45;
 325
 326
 327     //we assume that at slow speed ships will manoeuvre using engines/bow thruster
 328     if (fabs(speed)<=5)
 329         _sp_turn_radius_ft = _fixed_turn_radius;
 330     else {
 331         // adjust turn radius for speed. The equation is very approximate.
 332         // we need to allow for negative speeds
 333         if (type == "ship")
 334         _sp_turn_radius_ft = 10 * pow ((fabs(speed) - 15), 2) + turn_radius_ft;
 335         else
 336             _sp_turn_radius_ft = turn_radius_ft;
 337
 338     }
 339
 340     if (_rudder <= -0.25 || _rudder >= 0.25) {
 341         // adjust turn radius for _rudder angle. The equation is even more approximate.
 342         float a = 19;
 343         float b = -0.2485;
 344         float c = 0.543;
 345
 346         _rd_turn_radius_ft = (a * exp(b * fabs(_rudder)) + c) * _sp_turn_radius_ft;
 347
 348         // calculate the angle, alpha, subtended by the arc traversed in time dt
 349         alpha = ((speed * 1.686 * dt) / _rd_turn_radius_ft) * SG_RADIANS_TO_DEGREES;
 350         //cout << _name << " alpha " << alpha << endl;
 351         // make sure that alpha is applied in the right direction
 352         hdg += alpha * sign(_rudder);
 353
 354         SG_NORMALIZE_RANGE(hdg, 0.0, 360.0);
 355
 356         //adjust roll for rudder angle and speed. Another bit of voodoo
 357         raw_roll = _roll_factor * speed * _rudder;
 358     } else {
 359         // _rudder angle is 0
 360         raw_roll = 0;
 361     }
 362
 363     //low pass filter
 364     if (speed < 0)
 365         roll = -roll;
 366
 367     roll = (raw_roll * _roll_constant) + (roll * (1 - _roll_constant));
 368
 369     // adjust target _rudder angle if heading lock engaged
 370     double rudder_diff = 0.0;
 371     if (_hdg_lock) {
 372         double rudder_sense = 0.0;
 373         double diff = fabs(hdg - tgt_heading);
 374         //cout << "_rudder diff" << diff << endl;
 375         if (diff > 180)
 376             diff = fabs(diff - 360);
 377
 378         double sum = hdg + diff;
 379
 380         if (sum > 360.0)
 381             sum -= 360.0;
 382
 383         if (fabs(sum - tgt_heading)< 1.0)
 384             rudder_sense = 1.0;
 385         else
 386             rudder_sense = -1.0;
 387
 388         if (speed < 0)
 389             rudder_sense = -rudder_sense;
 390
 391         if (diff < 15)
 392             _tgt_rudder = diff * rudder_sense;
 393         else
 394             _tgt_rudder = 45 * rudder_sense;
 395
 396         rudder_diff = _tgt_rudder - _rudder;
 397     }
 398
 399     // set the _rudder limit by speed
 400     if (type == "ship"){
 401
 402     if (speed <= 40)
 403         rudder_limit = (-0.825 * speed) + 35;
 404     else
 405         rudder_limit = 2;
 406
 407     } else
 408         rudder_limit = 20;
 409
 410     if (fabs(rudder_diff)> 0.1) { // apply dead zone
 411
 412         if (rudder_diff > 0.0) {
 413             _rudder += _rudder_constant * dt;
 414
 415             if (_rudder > rudder_limit) // apply the _rudder limit
 416                 _rudder = rudder_limit;
 417
 418         } else if (rudder_diff < 0.0) {
 419             _rudder -= _rudder_constant * dt;
 420
 421             if (_rudder < -rudder_limit)
 422                 _rudder = -rudder_limit;
 423
 424         }
 425
 426         // do calculations for radar
 427         UpdateRadar(manager);
 428     }
 429 }//end function
 430
 431 void FGAIShip::AccelTo(double speed) {
 432     tgt_speed = speed;
 433 }
 434
 435 void FGAIShip::PitchTo(double angle) {
 436     tgt_pitch = angle;
 437 }
 438
 439 void FGAIShip::RollTo(double angle) {
 440     tgt_roll = angle;
 441 }
 442
 443 void FGAIShip::YawTo(double angle) {
 444 }
 445
 446 void FGAIShip::ClimbTo(double altitude) {
 447     tgt_altitude_ft = altitude;
 448     _setAltitude(altitude);
 449 }
 450
 451 void FGAIShip::TurnTo(double heading) {
 452     //double relbrg_corr = _relbrg;
 453
 454     //if ( relbrg_corr > 5)
 455     //    relbrg_corr = 5;
 456     //else if( relbrg_corr < -5)
 457     //    relbrg_corr = -5;
 458
 459     tgt_heading = heading - _lead_angle + _tow_angle;
 460     SG_NORMALIZE_RANGE(tgt_heading, 0.0, 360.0);
 461     _hdg_lock = true;
 462 }
 463
 464 double FGAIShip::sign(double x) {
 465     if (x < 0.0)
 466         return -1.0;
 467     else
 468         return 1.0;
 469 }
 470
 471 void FGAIShip::setFlightPlan(FGAIFlightPlan* f) {
 472     fp = f;
 473 }
 474
 475 void FGAIShip::setName(const string& n) {
 476     _name = n;
 477 }
 478
 479 void FGAIShip::setStartTime(const string& st) {
 480     _start_time = st;
 481 }
 482
 483 void FGAIShip::setUntilTime(const string& ut) {
 484     _until_time = ut;
 485     props->setStringValue("waypoint/wait-until-time", _until_time.c_str());
 486 }
 487
 488 void FGAIShip::setCurrName(const string& c) {
 489     _curr_name = c;
 490     props->setStringValue("waypoint/name-curr", _curr_name.c_str());
 491 }
 492
 493 void FGAIShip::setNextName(const string& n) {
 494     _next_name = n;
 495     props->setStringValue("waypoint/name-next", _next_name.c_str());
 496 }
 497
 498 void FGAIShip::setPrevName(const string& p) {
 499     _prev_name = p;
 500     props->setStringValue("waypoint/name-prev", _prev_name.c_str());
 501 }
 502
 503 void FGAIShip::setRepeat(bool r) {
 504     _repeat = r;
 505 }
 506
 507 void FGAIShip::setMissed(bool m) {
 508     _missed = m;
 509     props->setBoolValue("waypoint/missed", _missed);
 510 }
 511
 512 void FGAIShip::setRudder(float r) {
 513     _rudder = r;
 514 }
 515
 516 void FGAIShip::setRoll(double rl) {
 517     roll = rl;
 518 }
 519
 520 void FGAIShip::setLeadAngleGain(double g) {
 521     _lead_angle_gain = g;
 522 }
 523
 524 void FGAIShip::setLeadAngleLimit(double l) {
 525     _lead_angle_limit = l;
 526 }
 527
 528 void FGAIShip::setLeadAngleProp(double p) {
 529     _proportion = p;
 530 }
 531
 532 void FGAIShip::setRudderConstant(double rc) {
 533     _rudder_constant = rc;
 534 }
 535
 536 void FGAIShip::setSpeedConstant(double sc) {
 537     _speed_constant = sc;
 538 }
 539
 540 void FGAIShip::setFixedTurnRadius(double ftr) {
 541     _fixed_turn_radius = ftr;
 542 }
 543
 544 void FGAIShip::setWPNames() {
 545
 546     if (prev != 0)
 547         setPrevName(prev->name);
 548     else
 549         setPrevName("");
 550
 551     if (curr != 0)
 552     setCurrName(curr->name);
 553     else{
 554         setCurrName("");
 555         SG_LOG(SG_GENERAL, SG_ALERT, "AIShip: current wp name error" );
 556     }
 557
 558     if (next != 0)
 559         setNextName(next->name);
 560     else
 561         setNextName("");
 562
 563     SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: prev wp name " << prev->name);
 564     SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: current wp name " << curr->name);
 565     SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: next wp name " << next->name);
 566
 567 }
 568
 569 double FGAIShip::getRange(double lat, double lon, double lat2, double lon2) const {
 570
 571     double course, distance, az2;
 572
 573     //calculate the bearing and range of the second pos from the first
 574     geo_inverse_wgs_84(lat, lon, lat2, lon2, &course, &az2, &distance);
 575     distance *= SG_METER_TO_NM;
 576     return distance;
 577 }
 578
 579 double FGAIShip::getCourse(double lat, double lon, double lat2, double lon2) const {
 580
 581     double course, distance, recip;
 582
 583     //calculate the bearing and range of the second pos from the first
 584     geo_inverse_wgs_84(lat, lon, lat2, lon2, &course, &recip, &distance);
 585     if (tgt_speed >= 0) {
 586         return course;
 587         SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: course " << course);
 588     } else {
 589         return recip;
 590         SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: recip " << recip);
 591     }
 592 }
 593
 594 void FGAIShip::ProcessFlightPlan(double dt) {
 595
 596     double time_sec = getDaySeconds();
 597     double until_time_sec = 0;
 598
 599     _missed = false;
 600     _dt_count += dt;
 601
 602     ///////////////////////////////////////////////////////////////////////////
 603     // Check Execution time (currently once every 1 sec)
 604     // Add a bit of randomization to prevent the execution of all flight plans
 605     // in synchrony, which can add significant periodic framerate flutter.
 606     ///////////////////////////////////////////////////////////////////////////
 607
 608     //cout << "_start_sec " << _start_sec << " time_sec " << time_sec << endl;
 609     if (_dt_count < _next_run && _start_sec < time_sec)
 610         return;
 611
 612     _next_run = 1.0 + (0.5 * sg_random());
 613
 614     // check to see if we've reached the point for our next turn
 615     // if the range to the waypoint is less than the calculated turn
 616     // radius we can start the turn to the next leg
 617     _wp_range = getRange(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr->latitude, curr->longitude);
 618     _range_rate = (_wp_range - _old_range) / _dt_count;
 619     double sp_turn_radius_nm = _sp_turn_radius_ft / 6076.1155;
 620     // we need to try to identify a _missed waypoint
 621
 622     // calculate the time needed to turn through an arc of 90 degrees,
 623     // and allow a time error
 624     if (speed != 0)
 625         _missed_time_sec = 10 + ((SGD_PI * sp_turn_radius_nm * 60 * 60) / (2 * fabs(speed)));
 626     else
 627         _missed_time_sec = 10;
 628
 629     _missed_range = 4 * sp_turn_radius_nm;
 630
 631     //cout << _name << " range_rate " << _range_rate << " " << _new_waypoint<< endl ;
 632     //if ((_range_rate > 0) && !_new_waypoint){
 633     if (_range_rate > 0 && _wp_range < _missed_range && !_new_waypoint){
 634         _missed_count += _dt_count;
 635     }
 636
 637     if (_missed_count >= 120)
 638         setMissed(true);
 639     else if (_missed_count >= _missed_time_sec)
 640         setMissed(true);
 641     else
 642         setMissed(false);
 643
 644     _old_range = _wp_range;
 645     setWPNames();
 646
 647     if ((_wp_range < (sp_turn_radius_nm * 1.25)) || _missed || (_waiting && !_new_waypoint)) {
 648
 649         if (_next_name == "END" || fp->getNextWaypoint() == 0) {
 650
 651             if (_repeat) {
 652                 SG_LOG(SG_GENERAL, SG_ALERT, "AIShip: "<< _name << "Flightplan restarting ");
 653                 fp->restart();
 654                 prev = curr;
 655                 curr = fp->getCurrentWaypoint();
 656                 next = fp->getNextWaypoint();
 657                 setWPNames();
 658                 _wp_range = getRange(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr->latitude, curr->longitude);
 659                 _old_range = _wp_range;
 660                 _range_rate = 0;
 661                 _new_waypoint = true;
 662                 _missed_count = 0;
 663                 _lead_angle = 0;
 664                 AccelTo(prev->speed);
 665             } else {
 666                 SG_LOG(SG_GENERAL, SG_ALERT, "AIShip: " << _name << " Flightplan dying ");
 667                 setDie(true);
 668                 _dt_count = 0;
 669                 return;
 670             }
 671
 672         } else if (_next_name == "WAIT") {
 673
 674             if (_wait_count < next->time_sec) {
 675                 SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: " << _name << " waiting ");
 676                 setSpeed(0);
 677                 _waiting = true;
 678                 _wait_count += _dt_count;
 679                 _dt_count = 0;
 680                 _lead_angle = 0;
 681                 return;
 682             } else {
 683                 SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: " << _name
 684                     << " wait done: getting new waypoints ");
 685                 _waiting = false;
 686                 _wait_count = 0;
 687                 fp->IncrementWaypoint(false);
 688                 next = fp->getNextWaypoint();
 689
 690                 if (next->name == "WAITUNTIL" || next->name == "WAIT"
 691                         || next->name == "END")
 692                     return;
 693
 694                 prev = curr;
 695                 fp->IncrementWaypoint(false);
 696                 curr = fp->getCurrentWaypoint();
 697                 next = fp->getNextWaypoint();
 698             }
 699
 700         } else if (_next_name == "WAITUNTIL") {
 701             time_sec = getDaySeconds();
 702             until_time_sec = processTimeString(next->time);
 703             _until_time = next->time;
 704             setUntilTime(next->time);
 705             if (until_time_sec > time_sec) {
 706                 SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: " << _name << " "
 707                     << curr->name << " waiting until: "
 708                     << _until_time << " " << until_time_sec << " now " << time_sec );
 709                 setSpeed(0);
 710                 _lead_angle = 0;
 711                 _waiting = true;
 712                 return;
 713             } else {
 714                 SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: "
 715                     << _name << " wait until done: getting new waypoints ");
 716                 setUntilTime("");
 717                 fp->IncrementWaypoint(false);
 718
 719                 while (next->name == "WAITUNTIL") {
 720                     fp->IncrementWaypoint(false);
 721                     next = fp->getNextWaypoint();
 722                 }
 723
 724                 if (next->name == "WAIT")
 725                     return;
 726
 727                 prev = curr;
 728                 fp->IncrementWaypoint(false);
 729                 curr = fp->getCurrentWaypoint();
 730                 next = fp->getNextWaypoint();
 731                 _waiting = false;
 732             }
 733
 734         } else {
 735             //now reorganise the waypoints, so that next becomes current and so on
 736             SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: " << _name << " getting new waypoints ");
 737             fp->IncrementWaypoint(false);
 738             prev = fp->getPreviousWaypoint(); //first waypoint
 739             curr = fp->getCurrentWaypoint();  //second waypoint
 740             next = fp->getNextWaypoint();     //third waypoint (might not exist!)
 741         }
 742
 743         setWPNames();
 744         _new_waypoint = true;
 745         _missed_count = 0;
 746         _range_rate = 0;
 747         _lead_angle = 0;
 748         _wp_range = getRange(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr->latitude, curr->longitude);
 749         _old_range = _wp_range;
 750         setWPPos();
 751         AccelTo(prev->speed);
 752
 753     } else {
 754         _new_waypoint = false;
 755     }
 756
 757     //   now revise the required course for the next way point
 758     _course = getCourse(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr->latitude, curr->longitude);
 759
 760     if (finite(_course))
 761         TurnTo(_course);
 762     else
 763         SG_LOG(SG_GENERAL, SG_ALERT, "AIShip: Bearing or Range is not a finite number");
 764
 765      _dt_count = 0;
 766 } // end Processing FlightPlan
 767
 768 bool FGAIShip::initFlightPlan() {
 769
 770     SG_LOG(SG_GENERAL, SG_ALERT, "AIShip: " << _name << " initializing waypoints ");
 771
 772     bool init = false;
 773
 774     _start_sec = 0;
 775
 776     fp->restart();
 777     fp->IncrementWaypoint(false);
 778
 779     prev = fp->getPreviousWaypoint(); //first waypoint
 780     curr = fp->getCurrentWaypoint();  //second waypoint
 781     next = fp->getNextWaypoint();     //third waypoint (might not exist!)
 782
 783     while (curr->name == "WAIT" || curr->name == "WAITUNTIL") {  // don't wait when initialising
 784         SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: " << _name << " re-initializing waypoints ");
 785         fp->IncrementWaypoint(false);
 786         curr = fp->getCurrentWaypoint();
 787         next = fp->getNextWaypoint();
 788     }
 789
 790     if (!_start_time.empty()){
 791         _start_sec = processTimeString(_start_time);
 792         double day_sec = getDaySeconds();
 793
 794         if (_start_sec < day_sec){
 795             //cout << "flight plan has already started " << _start_time << endl;
 796             init = advanceFlightPlan(_start_sec, day_sec);
 797
 798         } else if (_start_sec > day_sec && _repeat) {
 799             //cout << "flight plan has not started, " << _start_time;
 800             //cout << "offsetting start time by -24 hrs" << endl;
 801             _start_sec -= _day;
 802             init = advanceFlightPlan(_start_sec, day_sec);
 803         }
 804
 805         if (init)
 806             _start_sec = 0; // set to zero for an immediate start of the Flight Plan
 807         else {
 808             fp->restart();
 809             fp->IncrementWaypoint(false);
 810             prev = fp->getPreviousWaypoint();
 811             curr = fp->getCurrentWaypoint();
 812             next = fp->getNextWaypoint();
 813             return false;
 814         }
 815
 816     } else {
 817     setLatitude(prev->latitude);
 818     setLongitude(prev->longitude);
 819     setSpeed(prev->speed);
 820     }
 821
 822     setWPNames();
 823     setHeading(getCourse(prev->latitude, prev->longitude, curr->latitude, curr->longitude));
 824     _wp_range = getRange(prev->latitude, prev->longitude, curr->latitude, curr->longitude);
 825     _old_range = _wp_range;
 826     _range_rate = 0;
 827     _hdg_lock = true;
 828     _missed = false;
 829     _missed_count = 0;
 830     _new_waypoint = true;
 831
 832     SG_LOG(SG_GENERAL, SG_ALERT, "AIShip: " << _name << " done initialising waypoints ");
 833     if (prev)
 834         init = true;
 835
 836     if (init)
 837         return true;
 838     else
 839         return false;
 840
 841 } // end of initialization
 842
 843
 844 double FGAIShip::processTimeString(const string& theTime) {
 845
 846     int Hour;
 847     int Minute;
 848     int Second;
 849
 850     // first split theTime string into
 851     //  hour, minute, second and convert to int;
 852     Hour   = atoi(theTime.substr(0,2).c_str());
 853     Minute = atoi(theTime.substr(3,5).c_str());
 854     Second = atoi(theTime.substr(6,8).c_str());
 855
 856     // offset by a day-sec to allow for starting a day earlier
 857     double time_seconds = Hour * 3600
 858         + Minute * 60
 859         + Second;
 860
 861     return time_seconds;
 862 }
 863
 864 double FGAIShip::getDaySeconds () {
 865     // Date and time
 866     struct tm *t = globals->get_time_params()->getGmt();
 867
 868     double day_seconds = t->tm_hour * 3600
 869         + t->tm_min * 60
 870         + t->tm_sec;
 871
 872     return day_seconds;
 873 }
 874
 875 bool FGAIShip::advanceFlightPlan (double start_sec, double day_sec) {
 876
 877     double elapsed_sec = start_sec;
 878     double distance_nm = 0;
 879
 880     //cout << "advancing flight plan start_sec: " << start_sec << " " << day_sec << endl;
 881
 882     while ( elapsed_sec < day_sec ) {
 883
 884         if (next->name == "END" || fp->getNextWaypoint() == 0) {
 885
 886             if (_repeat ) {
 887                 //cout << _name << ": " << "restarting flightplan" << endl;
 888                 fp->restart();
 889                 curr = fp->getCurrentWaypoint();
 890                 next = fp->getNextWaypoint();
 891             } else {
 892                 //cout << _name << ": " << "ending flightplan" << endl;
 893                 setDie(true);
 894                 return false;
 895             }
 896
 897         } else if (next->name == "WAIT") {
 898             //cout << _name << ": begin WAIT: " << prev->name << " ";
 899             //cout << curr->name << " " << next->name << endl;
 900
 901             elapsed_sec += next->time_sec;
 902
 903             if ( elapsed_sec >= day_sec)
 904                 continue;
 905
 906             fp->IncrementWaypoint(false);
 907             next = fp->getNextWaypoint();
 908
 909             if (next->name != "WAITUNTIL" && next->name != "WAIT"
 910                     && next->name != "END") {
 911                 prev = curr;
 912                 fp->IncrementWaypoint(false);
 913                 curr = fp->getCurrentWaypoint();
 914                 next = fp->getNextWaypoint();
 915             }
 916
 917         } else if (next->name == "WAITUNTIL") {
 918             double until_sec = processTimeString(next->time);
 919
 920             if (until_sec > _start_sec && start_sec < 0)
 921                 until_sec -= _day;
 922
 923             if (elapsed_sec < until_sec)
 924                 elapsed_sec = until_sec;
 925
 926             if (elapsed_sec >= day_sec )
 927                 break;
 928
 929             fp->IncrementWaypoint(false);
 930             next = fp->getNextWaypoint();
 931
 932             if (next->name != "WAITUNTIL" && next->name != "WAIT") {
 933                 prev = curr;
 934                 fp->IncrementWaypoint(false);
 935                 curr = fp->getCurrentWaypoint();
 936                 next = fp->getNextWaypoint();
 937             }
 938
 939             //cout << _name << ": end WAITUNTIL: ";
 940             //cout << prev->name << " " << curr->name << " " << next->name <<  endl;
 941
 942         } else {
 943             distance_nm = getRange(prev->latitude, prev->longitude, curr->latitude, curr->longitude);
 944             elapsed_sec += distance_nm * 60 * 60 / prev->speed;
 945
 946             if (elapsed_sec >= day_sec)
 947                 continue;
 948
 949             fp->IncrementWaypoint(false);
 950             prev = fp->getPreviousWaypoint();
 951             curr = fp->getCurrentWaypoint();
 952             next = fp->getNextWaypoint();
 953         }
 954
 955     }   // end while
 956
 957     // the required position lies between the previous and current waypoints
 958     // so we will calculate the distance back up the track from the current waypoint
 959     // then calculate the lat and lon.
 960
 961     /*cout << "advancing flight plan done elapsed_sec: " << elapsed_sec
 962         << " " << day_sec << endl;*/
 963
 964     double time_diff = elapsed_sec - day_sec;
 965     double lat, lon, recip;
 966
 967     //cout << " time diff " << time_diff << endl;
 968
 969     if (next->name == "WAIT" ){
 970         setSpeed(0);
 971         lat = curr->latitude;
 972         lon = curr->longitude;
 973         _wait_count= time_diff;
 974         _waiting = true;
 975     } else if (next->name == "WAITUNTIL") {
 976         setSpeed(0);
 977         lat = curr->latitude;
 978         lon = curr->longitude;
 979         _waiting = true;
 980     } else {
 981         setSpeed(prev->speed);
 982         distance_nm = speed * time_diff / (60 * 60);
 983         double brg = getCourse(curr->latitude, curr->longitude, prev->latitude, prev->longitude);
 984
 985         //cout << " brg " << brg << " from " << curr->name << " to " << prev->name << " "
 986         //    << " lat "  << curr->latitude << " lon " << curr->longitude
 987         //    << " distance m " << distance_nm * SG_NM_TO_METER << endl;
 988
 989         lat = geo_direct_wgs_84 (curr->latitude, curr->longitude, brg,
 990             distance_nm * SG_NM_TO_METER, &lat, &lon, &recip );
 991         lon = geo_direct_wgs_84 (curr->latitude, curr->longitude, brg,
 992             distance_nm * SG_NM_TO_METER, &lat, &lon, &recip );
 993         recip = geo_direct_wgs_84 (curr->latitude, curr->longitude, brg,
 994             distance_nm * SG_NM_TO_METER, &lat, &lon, &recip );
 995     }
 996
 997     setLatitude(lat);
 998     setLongitude(lon);
 999
1000     return true;
1001 }
1002
1003 void FGAIShip::setWPPos() {
1004
1005     if (curr->name == "END" || curr->name == "WAIT" || curr->name == "WAITUNTIL"){
1006         cout<< curr->name << endl;
1007         return;
1008     }
1009
1010     double elevation_m = 0;
1011     wppos.setLatitudeDeg(curr->latitude);
1012     wppos.setLongitudeDeg(curr->longitude);
1013     wppos.setElevationFt(0);
1014
1015     if (curr->on_ground){
1016
1017         if (globals->get_scenery()->get_elevation_m(SGGeod::fromGeodM(wppos, 10000),
1018             elevation_m, &_material)){
1019                 wppos.setElevationM(elevation_m);
1020         }
1021
1022     } else {
1023         wppos.setElevationFt(curr->altitude);
1024     }
1025
1026 }
1027
1028 void FGAIShip::setXTrackError() {
1029
1030     double course = getCourse(prev->latitude, prev->longitude,
1031         curr->latitude, curr->longitude);
1032     double brg = getCourse(pos.getLatitudeDeg(), pos.getLongitudeDeg(),
1033         curr->latitude, curr->longitude);
1034     double xtrack_error_nm = sin((course - brg)* SG_DEGREES_TO_RADIANS) * _wp_range;
1035
1036     //if (_wp_range > _sp_turn_radius_ft / (2 * 6076.1155)){
1037     if (_wp_range > 0){
1038         _lead_angle = atan2(xtrack_error_nm,(_wp_range * _proportion)) * SG_RADIANS_TO_DEGREES;
1039     } else
1040         _lead_angle = 0;
1041
1042     _lead_angle *= _lead_angle_gain;
1043     _xtrack_error = xtrack_error_nm * 6076.1155;
1044
1045     if (_lead_angle<= -_lead_angle_limit)
1046         _lead_angle = -_lead_angle_limit;
1047     else if (_lead_angle >= _lead_angle_limit)
1048         _lead_angle = _lead_angle_limit;
1049
1050 }