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