src/AIModel/AIGroundVehicle.cxx

   1 // FGAIGroundVehicle - FGAIShip-derived class creates an AI Ground Vehicle
   2 // by adding a ground following utility
   3 //
   4 // Written by Vivian Meazza, started August 2009.
   5 // - vivian.meazza at lineone.net
   6 //
   7 // This program is free software; you can redistribute it and/or
   8 // modify it under the terms of the GNU General Public License as
   9 // published by the Free Software Foundation; either version 2 of the
  10 // License, or (at your option) any later version.
  11 //
  12 // This program is distributed in the hope that it will be useful, but
  13 // WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 // General Public License for more details.
  16 //
  17 // You should have received a copy of the GNU General Public License
  18 // along with this program; if not, write to the Free Software
  19 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  20
  21 #ifdef HAVE_CONFIG_H
  22 #  include <config.h>
  23 #endif
  24
  25 #include <simgear/sg_inlines.h>
  26
  27 #include <Main/viewer.hxx>
  28 #include <Scenery/scenery.hxx>
  29 #include <Scenery/tilemgr.hxx>
  30 #include <Airports/dynamics.hxx>
  31
  32 #include "AIGroundVehicle.hxx"
  33
  34 FGAIGroundVehicle::FGAIGroundVehicle() :
  35 FGAIShip(otGroundVehicle),
  36
  37 _pitch(0),
  38 _pitch_deg(0),
  39 _speed_kt(0),
  40 _selected_ac(0),
  41 _range_ft(0),
  42 _relbrg (0),
  43 _parent_speed(0),
  44 _dt_count(0),
  45 _next_run(0),
  46 _parent_x_offset(0),
  47 _parent_y_offset(0),
  48 _parent_z_offset(0),
  49 _parent(""),
  50 _break_count(0)
  51
  52 {
  53     invisible = false;
  54 }
  55
  56 FGAIGroundVehicle::~FGAIGroundVehicle() {}
  57
  58 void FGAIGroundVehicle::readFromScenario(SGPropertyNode* scFileNode) {
  59     if (!scFileNode)
  60         return;
  61
  62     FGAIShip::readFromScenario(scFileNode);
  63
  64     setNoRoll(scFileNode->getBoolValue("no-roll", true));
  65     setName(scFileNode->getStringValue("name", "groundvehicle"));
  66     setSMPath(scFileNode->getStringValue("submodel-path", ""));
  67     setContactX1offset(scFileNode->getDoubleValue("contact-x1-offset", 0.0));
  68     setContactX2offset(scFileNode->getDoubleValue("contact-x2-offset", 0.0));
  69     setXOffset(scFileNode->getDoubleValue("hitch-x-offset", 35.0));
  70     setYOffset(scFileNode->getDoubleValue("hitch-y-offset", 0.0));
  71     setZOffset(scFileNode->getDoubleValue("hitch-z-offset", 0.0));
  72     setPitchoffset(scFileNode->getDoubleValue("pitch-offset", 0.0));
  73     setRolloffset(scFileNode->getDoubleValue("roll-offset", 0.0));
  74     setYawoffset(scFileNode->getDoubleValue("yaw-offset", 0.0));
  75     setPitchCoeff(scFileNode->getDoubleValue("pitch-coefficient", 0.1));
  76     setElevCoeff(scFileNode->getDoubleValue("elevation-coefficient", 0.25));
  77     setParentName(scFileNode->getStringValue("parent", ""));
  78     setTowAngleGain(scFileNode->getDoubleValue("tow-angle-gain", 1.0));
  79     setTowAngleLimit(scFileNode->getDoubleValue("tow-angle-limit-deg", 2.0));
  80     setInitialTunnel(scFileNode->getBoolValue("tunnel", false));
  81     //we may need these later for towed vehicles
  82     //    setSubID(scFileNode->getIntValue("SubID", 0));
  83     //    setGroundOffset(scFileNode->getDoubleValue("ground-offset", 0.0));
  84     //    setFormate(scFileNode->getBoolValue("formate", true));
  85 }
  86
  87 void FGAIGroundVehicle::bind() {
  88     FGAIShip::bind();
  89
  90     props->tie("controls/constants/elevation-coeff",
  91         SGRawValuePointer<double>(&_elevation_coeff));
  92     props->tie("controls/constants/pitch-coeff",
  93         SGRawValuePointer<double>(&_pitch_coeff));
  94     props->tie("position/ht-AGL-ft",
  95         SGRawValuePointer<double>(&_ht_agl_ft));
  96     props->tie("hitch/rel-bearing-deg",
  97          SGRawValuePointer<double>(&_relbrg));
  98     props->tie("hitch/tow-angle-deg",
  99          SGRawValuePointer<double>(&_tow_angle));
 100     props->tie("hitch/range-ft",
 101         SGRawValuePointer<double>(&_range_ft));
 102     props->tie("hitch/x-offset-ft",
 103         SGRawValuePointer<double>(&_x_offset));
 104     props->tie("hitch/y-offset-ft",
 105         SGRawValuePointer<double>(&_y_offset));
 106     props->tie("hitch/z-offset-ft",
 107         SGRawValuePointer<double>(&_z_offset));
 108     props->tie("hitch/parent-x-offset-ft",
 109         SGRawValuePointer<double>(&_parent_x_offset));
 110     props->tie("hitch/parent-y-offset-ft",
 111         SGRawValuePointer<double>(&_parent_y_offset));
 112     props->tie("hitch/parent-z-offset-ft",
 113         SGRawValuePointer<double>(&_parent_z_offset));
 114     props->tie("controls/constants/tow-angle/gain",
 115         SGRawValuePointer<double>(&_tow_angle_gain));
 116     props->tie("controls/constants/tow-angle/limit-deg",
 117         SGRawValuePointer<double>(&_tow_angle_limit));
 118     props->tie("controls/contact-x1-offset-ft",
 119         SGRawValuePointer<double>(&_contact_x1_offset));
 120     props->tie("controls/contact-x2-offset-ft",
 121         SGRawValuePointer<double>(&_contact_x2_offset));
 122 }
 123
 124 void FGAIGroundVehicle::unbind() {
 125     FGAIShip::unbind();
 126
 127     props->untie("controls/constants/elevation-coeff");
 128         props->untie("controls/constants/pitch-coeff");
 129     props->untie("position/ht-AGL-ft");
 130     props->untie("hitch/rel-bearing-deg");
 131     props->untie("hitch/tow-angle-deg");
 132     props->untie("hitch/range-ft");
 133     props->untie("hitch/x-offset-ft");
 134     props->untie("hitch/y-offset-ft");
 135     props->untie("hitch/z-offset-ft");
 136     props->untie("hitch/parent-x-offset-ft");
 137     props->untie("hitch/parent-y-offset-ft");
 138     props->untie("hitch/parent-y-offset-ft");
 139     props->untie("controls/constants/tow-angle/gain");
 140     props->untie("controls/constants/tow-angle/limit-deg");
 141     props->untie("controls/contact-x1-offset-ft");
 142     props->untie("controls/contact-x2-offset-ft");
 143 }
 144
 145 bool FGAIGroundVehicle::init(bool search_in_AI_path) {
 146     if (!FGAIShip::init(search_in_AI_path))
 147         return false;
 148
 149     invisible = false;
 150     _limit = 200;
 151     no_roll = true;
 152
 153     return true;
 154 }
 155
 156 void FGAIGroundVehicle::update(double dt) {
 157     //    SG_LOG(SG_GENERAL, SG_ALERT, "updating GroundVehicle: " << _name );
 158     FGAIShip::update(dt);
 159
 160     RunGroundVehicle(dt);
 161 }
 162
 163 void FGAIGroundVehicle::setNoRoll(bool nr) {
 164     no_roll = nr;
 165 }
 166
 167 void FGAIGroundVehicle::setContactX1offset(double x1) {
 168     _contact_x1_offset = x1;
 169 }
 170
 171 void FGAIGroundVehicle::setContactX2offset(double x2) {
 172     _contact_x2_offset = x2;
 173 }
 174
 175 void FGAIGroundVehicle::setXOffset(double x) {
 176     _x_offset = x;
 177 }
 178
 179 void FGAIGroundVehicle::setYOffset(double y) {
 180     _y_offset = y;
 181 }
 182
 183 void FGAIGroundVehicle::setZOffset(double z) {
 184     _z_offset = z;
 185 }
 186
 187 void FGAIGroundVehicle::setPitchCoeff(double pc) {
 188     _pitch_coeff = pc;
 189 }
 190
 191 void FGAIGroundVehicle::setElevCoeff(double ec) {
 192     _elevation_coeff = ec;
 193 }
 194
 195 void FGAIGroundVehicle::setTowAngleGain(double g) {
 196     _tow_angle_gain = g;
 197 }
 198
 199 void FGAIGroundVehicle::setTowAngleLimit(double l) {
 200     _tow_angle_limit = l;
 201 }
 202
 203 void FGAIGroundVehicle::setElevation(double h, double dt, double coeff){
 204     double c = dt / (coeff + dt);
 205     _elevation_ft = (h * c) + (_elevation_ft * (1 - c));
 206 }
 207
 208 void FGAIGroundVehicle::setPitch(double p, double dt, double coeff){
 209     double c = dt / (coeff + dt);
 210     _pitch_deg = (p * c) + (_pitch_deg * (1 - c));
 211 }
 212
 213 void FGAIGroundVehicle::setParentName(const string& p) {
 214     _parent = p;
 215 }
 216
 217 void FGAIGroundVehicle::setTowAngle(double ta, double dt, double coeff){
 218     ta *= _tow_angle_gain;
 219     double factor = -0.0045 * speed + 1;
 220     double limit = _tow_angle_limit * factor;
 221 //      cout << "speed "<< speed << " _factor " << _factor<<" " <<_tow_angle_limit<< endl;
 222      _tow_angle = pow(ta,2) * sign(ta) * factor;
 223     SG_CLAMP_RANGE(_tow_angle, -limit, limit);
 224 }
 225
 226 bool FGAIGroundVehicle::getGroundElev(SGGeod inpos) {
 227
 228     double height_m ;
 229
 230     if (globals->get_scenery()->get_elevation_m(SGGeod::fromGeodM(inpos, 3000), height_m, &_material,0)){
 231             _ht_agl_ft = inpos.getElevationFt() - height_m * SG_METER_TO_FEET;
 232
 233             if (_material) {
 234                 const vector<string>& names = _material->get_names();
 235
 236                 _solid = _material->get_solid();
 237
 238                 if (!names.empty())
 239                     props->setStringValue("material/name", names[0].c_str());
 240                 else
 241                     props->setStringValue("material/name", "");
 242
 243                 //cout << "material " << names[0].c_str()
 244                 //    << " _elevation_m " << _elevation_m
 245                 //    << " solid " << _solid
 246                 //    << " load " << _load_resistance
 247                 //    << " frictionFactor " << _frictionFactor
 248                 //    << endl;
 249
 250             }
 251
 252             return true;
 253     } else {
 254         return false;
 255     }
 256
 257 }
 258
 259 bool FGAIGroundVehicle::getPitch() {
 260
 261     if (!_tunnel){
 262         double vel = props->getDoubleValue("velocities/true-airspeed-kt", 0);
 263         double contact_offset_x1_m = _contact_x1_offset * SG_FEET_TO_METER;
 264         double contact_offset_x2_m = _contact_x2_offset * SG_FEET_TO_METER;
 265         double _z_offset_m = _parent_z_offset * SG_FEET_TO_METER;
 266
 267         SGVec3d front(-contact_offset_x1_m, 0, 0);
 268         SGVec3d rear(-contact_offset_x2_m, 0, 0);
 269         SGVec3d Front = getCartPosAt(front);
 270         SGVec3d Rear = getCartPosAt(rear);
 271
 272         SGGeod geodFront = SGGeod::fromCart(Front);
 273         SGGeod geodRear = SGGeod::fromCart(Rear);
 274
 275         double front_elev_m = 0;
 276         double rear_elev_m = 0;
 277         double elev_front = 0;
 278         double elev_rear = 0;
 279         double max_alt = 10000;
 280
 281         if (globals->get_scenery()->get_elevation_m(SGGeod::fromGeodM(geodFront, 3000),
 282             elev_front, &_material, 0)){
 283                 front_elev_m = elev_front + _z_offset_m;
 284         } else
 285             return false;
 286
 287         if (globals->get_scenery()->get_elevation_m(SGGeod::fromGeodM(geodRear, 3000),
 288             elev_rear, &_material, 0)){
 289                 rear_elev_m = elev_rear;
 290         } else
 291             return false;
 292
 293         if (vel >= 0){
 294             double diff = front_elev_m - rear_elev_m;
 295             _pitch = atan2 (diff,
 296                 fabs(contact_offset_x1_m) + fabs(contact_offset_x2_m)) * SG_RADIANS_TO_DEGREES;
 297             _elevation = (rear_elev_m + diff/2) * SG_METER_TO_FEET;
 298         } else {
 299             double diff = rear_elev_m - front_elev_m;
 300             _pitch = atan2 (diff,
 301                 fabs(contact_offset_x1_m) + fabs(contact_offset_x2_m)) * SG_RADIANS_TO_DEGREES;
 302             _elevation = (front_elev_m + diff/2) * SG_METER_TO_FEET;
 303             _pitch = -_pitch;
 304         }
 305
 306     } else {
 307
 308         if (prev->altitude == 0 || curr->altitude == 0) return false;
 309
 310         static double distance;
 311         static double d_alt;
 312         static double curr_alt;
 313         static double prev_alt;
 314
 315         if (_new_waypoint){
 316             //cout << "new waypoint, calculating pitch " << endl;
 317             curr_alt = curr->altitude;
 318             prev_alt = prev->altitude;
 319             //cout << "prev_alt" <<prev_alt << endl;
 320             d_alt = (curr_alt - prev_alt) * SG_METER_TO_FEET;
 321             //_elevation = prev->altitude;
 322             distance = SGGeodesy::distanceM(SGGeod::fromDeg(prev->longitude, prev->latitude),
 323             SGGeod::fromDeg(curr->longitude, curr->latitude));
 324             _pitch = atan2(d_alt, distance * SG_METER_TO_FEET) * SG_RADIANS_TO_DEGREES;
 325             //cout << "new waypoint, calculating pitch " <<  _pitch <<
 326             //    " " << _pitch_offset << " " << _elevation <<endl;
 327         }
 328
 329         double distance_to_go = SGGeodesy::distanceM(SGGeod::fromDeg(pos.getLongitudeDeg(), pos.getLatitudeDeg()),
 330             SGGeod::fromDeg(curr->longitude, curr->latitude));
 331
 332         /*cout << "tunnel " << _tunnel
 333              << " distance prev & curr " << prev->name << " " << curr->name << " " << distance * SG_METER_TO_FEET
 334              << " distance to go " << distance_to_go * SG_METER_TO_FEET
 335              << " d_alt ft " << d_alt
 336              << endl;*/
 337
 338         if (distance_to_go > distance)
 339             _elevation = prev_alt;
 340         else
 341             _elevation = curr_alt - (tan(_pitch * SG_DEGREES_TO_RADIANS) * distance_to_go * SG_METER_TO_FEET);
 342
 343     }
 344
 345     getGroundElev(pos);
 346
 347     return true;
 348 }
 349
 350 void FGAIGroundVehicle::setParent() {
 351
 352     const SGPropertyNode_ptr ai = fgGetNode("/ai/models", true);
 353
 354     for (int i = ai->nChildren() - 1; i >= -1; i--) {
 355         SGPropertyNode_ptr model;
 356
 357         if (i < 0) { // last iteration: selected model
 358             model = _selected_ac;
 359         } else {
 360             model = ai->getChild(i);
 361             string path = ai->getPath();
 362             const string name = model->getStringValue("name");
 363
 364             if (!model->nChildren()){
 365                 continue;
 366             }
 367             if (name == _parent) {
 368                 _selected_ac = model;  // save selected model for last iteration
 369                 break;
 370             }
 371
 372         }
 373         if (!model)
 374             continue;
 375
 376     }// end for loop
 377
 378     if (_selected_ac != 0){
 379         const string name = _selected_ac->getStringValue("name");
 380         double lat = _selected_ac->getDoubleValue("position/latitude-deg");
 381         double lon = _selected_ac->getDoubleValue("position/longitude-deg");
 382         double elevation = _selected_ac->getDoubleValue("position/altitude-ft");
 383         double hitch_x_offset_m = _selected_ac->getDoubleValue("hitch/x-offset-ft")
 384             * SG_FEET_TO_METER;
 385         double hitch_y_offset_m = _selected_ac->getDoubleValue("hitch/y-offset-ft")
 386             * SG_FEET_TO_METER;
 387         double hitch_z_offset_m = _selected_ac->getDoubleValue("hitch/z-offset-ft")
 388             * SG_FEET_TO_METER;
 389
 390         _selectedpos.setLatitudeDeg(lat);
 391         _selectedpos.setLongitudeDeg(lon);
 392         _selectedpos.setElevationFt(elevation);
 393
 394         _parent_x_offset = _selected_ac->getDoubleValue("hitch/x-offset-ft");
 395         _parent_y_offset = _selected_ac->getDoubleValue("hitch/y-offset-ft");
 396         _parent_z_offset = _selected_ac->getDoubleValue("hitch/z-offset-ft");
 397
 398         _parent_speed    = _selected_ac->getDoubleValue("velocities/true-airspeed-kt");
 399
 400         SGVec3d rear_hitch(-hitch_x_offset_m, hitch_y_offset_m, 0);
 401         SGVec3d RearHitch = getCartHitchPosAt(rear_hitch);
 402
 403         SGGeod rearpos = SGGeod::fromCart(RearHitch);
 404
 405         double user_lat = rearpos.getLatitudeDeg();
 406         double user_lon = rearpos.getLongitudeDeg();
 407
 408         double range, bearing;
 409
 410         calcRangeBearing(pos.getLatitudeDeg(), pos.getLongitudeDeg(),
 411             user_lat, user_lon, range, bearing);
 412         _range_ft = range * 6076.11549;
 413         _relbrg = calcRelBearingDeg(bearing, hdg);
 414     } else {
 415         SG_LOG(SG_GENERAL, SG_ALERT, "AIGroundVeh1cle: " << _name
 416                 << " parent not found: dying ");
 417         setDie(true);
 418     }
 419
 420 }
 421
 422 void FGAIGroundVehicle::calcRangeBearing(double lat, double lon, double lat2, double lon2,
 423                             double &range, double &bearing) const
 424 {
 425     // calculate the bearing and range of the second pos from the first
 426     double az2, distance;
 427     geo_inverse_wgs_84(lat, lon, lat2, lon2, &bearing, &az2, &distance);
 428     range = distance * SG_METER_TO_NM;
 429 }
 430
 431 double FGAIGroundVehicle::calcRelBearingDeg(double bearing, double heading)
 432 {
 433     double angle = bearing - heading;
 434     SG_NORMALIZE_RANGE(angle, -180.0, 180.0);
 435     return angle;
 436 }
 437
 438 SGVec3d FGAIGroundVehicle::getCartHitchPosAt(const SGVec3d& _off) const {
 439     double hdg = _selected_ac->getDoubleValue("orientation/true-heading-deg");
 440     double pitch = _selected_ac->getDoubleValue("orientation/pitch-deg");
 441     double roll = _selected_ac->getDoubleValue("orientation/roll-deg");
 442
 443     // Transform that one to the horizontal local coordinate system.
 444     SGQuatd hlTrans = SGQuatd::fromLonLat(_selectedpos);
 445
 446     // and postrotate the orientation of the AIModel wrt the horizontal
 447     // local frame
 448     hlTrans *= SGQuatd::fromYawPitchRollDeg(hdg, pitch, roll);
 449
 450     // The offset converted to the usual body fixed coordinate system
 451     // rotated to the earth fiexed coordinates axis
 452     SGVec3d off = hlTrans.backTransform(_off);
 453
 454     // Add the position offset of the AIModel to gain the earth centered position
 455     SGVec3d cartPos = SGVec3d::fromGeod(_selectedpos);
 456
 457     return cartPos + off;
 458 }
 459
 460 void FGAIGroundVehicle::AdvanceFP(){
 461
 462     double count = 0;
 463     string parent_next_name =_selected_ac->getStringValue("waypoint/name-next");
 464
 465     while(fp->getNextWaypoint() != 0 && fp->getNextWaypoint()->name != "END" && count < 5){
 466         SG_LOG(SG_GENERAL, SG_DEBUG, "AIGroundVeh1cle: " << _name
 467             <<" advancing waypoint to: " << parent_next_name);
 468
 469         if (fp->getNextWaypoint()->name == parent_next_name){
 470             SG_LOG(SG_GENERAL, SG_DEBUG, "AIGroundVeh1cle: " << _name
 471                 << " not setting waypoint already at: " << fp->getNextWaypoint()->name);
 472             return;
 473         }
 474
 475         prev = curr;
 476         fp->IncrementWaypoint(false);
 477         curr = fp->getCurrentWaypoint();
 478         next = fp->getNextWaypoint();
 479
 480         if (fp->getNextWaypoint()->name == parent_next_name){
 481             SG_LOG(SG_GENERAL, SG_DEBUG, "AIGroundVeh1cle: " << _name
 482             << " waypoint set to: " << fp->getNextWaypoint()->name);
 483             return;
 484         }
 485
 486         count++;
 487
 488     }// end while loop
 489
 490     while(fp->getPreviousWaypoint() != 0 && fp->getPreviousWaypoint()->name != "END"
 491         && count > -10){
 492             SG_LOG(SG_GENERAL, SG_DEBUG, "AIGroundVeh1cle: " << _name
 493             << " retreating waypoint to: " << parent_next_name
 494             << " at: " << fp->getNextWaypoint()->name);
 495
 496         if (fp->getNextWaypoint()->name == parent_next_name){
 497             SG_LOG(SG_GENERAL, SG_DEBUG, "AIGroundVeh1cle: " << _name
 498                 << " not setting waypoint already at:" << fp->getNextWaypoint()->name );
 499             return;
 500         }
 501
 502         prev = curr;
 503         fp->DecrementWaypoint(false);
 504         curr = fp->getCurrentWaypoint();
 505         next = fp->getNextWaypoint();
 506
 507         if (fp->getNextWaypoint()->name == parent_next_name){
 508             SG_LOG(SG_GENERAL, SG_DEBUG, "AIGroundVeh1cle: " << _name
 509             << " waypoint set to: " << fp->getNextWaypoint()->name);
 510             return;
 511         }
 512
 513         count--;
 514
 515     }// end while loop
 516 }
 517
 518 void FGAIGroundVehicle::setTowSpeed(){
 519
 520     double diff = _range_ft - _x_offset;
 521     double  x = 0;
 522
 523     if (_range_ft > _x_offset * 3) x = 50;
 524
 525     if (_relbrg < -90 || _relbrg > 90){
 526         setSpeed(_parent_speed - 5 - x);
 527         //cout << _name << " case 1r _relbrg spd - 5 " << _relbrg << " " << diff << endl;
 528     }else if (_range_ft > _x_offset + 0.25 && _relbrg >= -90 && _relbrg <= 90){
 529         setSpeed(_parent_speed + 1 + x);
 530         //cout << _name << " case 2r _relbrg spd + 1 " << _relbrg << " "
 531         //    << diff << " range " << _range_ft << endl;
 532     } else if (_range_ft < _x_offset - 0.25 && _relbrg >= -90 && _relbrg <= 90){
 533         setSpeed(_parent_speed - 1 - x);
 534         //cout << _name << " case 3r _relbrg spd - 2 " << _relbrg << " "
 535         //    << diff << " " << _range_ft << endl;
 536     } else {
 537         setSpeed(_parent_speed);
 538         //cout << _name << " else r _relbrg " << _relbrg << " " << diff << endl;
 539     }
 540
 541 }
 542
 543 void FGAIGroundVehicle::RunGroundVehicle(double dt){
 544
 545     _dt_count += dt;
 546
 547     ///////////////////////////////////////////////////////////////////////////
 548     // Check execution time (currently once every 0.05 sec or 20 fps)
 549     // Add a bit of randomization to prevent the execution of all flight plans
 550     // in synchrony, which can add significant periodic framerate flutter.
 551     // Randomization removed to get better appearance
 552     ///////////////////////////////////////////////////////////////////////////
 553
 554     //cout << "_start_sec " << _start_sec << " time_sec " << time_sec << endl;
 555     if (_dt_count < _next_run)
 556         return;
 557
 558     _next_run = 0.05 /*+ (0.015 * sg_random())*/;
 559
 560     if (getPitch()){
 561         setElevation(_elevation, _dt_count, _elevation_coeff);
 562         ClimbTo(_elevation_ft);
 563         setPitch(_pitch, _dt_count, _pitch_coeff);
 564         PitchTo(_pitch_deg);
 565     }
 566
 567     if(_parent == ""){
 568         AccelTo(prev->speed);
 569         _dt_count = 0;
 570         return;
 571     }
 572
 573     setParent();
 574
 575     string parent_next_name = _selected_ac->getStringValue("waypoint/name-next");
 576     bool parent_waiting = _selected_ac->getBoolValue("waypoint/waiting");
 577     bool parent_restart = _selected_ac->getBoolValue("controls/restart");
 578
 579     if (parent_next_name == "END" && fp->getNextWaypoint()->name != "END" ){
 580         SG_LOG(SG_GENERAL, SG_DEBUG, "AIGroundVeh1cle: " << _name
 581             << " setting END: getting new waypoints ");
 582         AdvanceFP();
 583         setWPNames();
 584         setTunnel(_initial_tunnel);
 585         if(_restart) _missed_count = 200;
 586         /*} else if (parent_next_name == "WAIT" && fp->getNextWaypoint()->name != "WAIT" ){*/
 587     } else if (parent_waiting && !_waiting){
 588         SG_LOG(SG_GENERAL, SG_DEBUG, "AIGroundVeh1cle: " << _name
 589             << " setting WAIT/WAITUNTIL: getting new waypoints ");
 590         AdvanceFP();
 591         setWPNames();
 592         _waiting = true;
 593     } else if (parent_next_name != "WAIT" && fp->getNextWaypoint()->name == "WAIT"){
 594         SG_LOG(SG_GENERAL, SG_DEBUG, "AIGroundVeh1cle: " << _name
 595             << " wait done: getting new waypoints ");
 596         _waiting = false;
 597         _wait_count = 0;
 598         fp->IncrementWaypoint(false);
 599         next = fp->getNextWaypoint();
 600
 601         if (next->name == "WAITUNTIL" || next->name == "WAIT"
 602             || next->name == "END"){
 603         } else {
 604             prev = curr;
 605             fp->IncrementWaypoint(false);
 606             curr = fp->getCurrentWaypoint();
 607             next = fp->getNextWaypoint();
 608         }
 609
 610         setWPNames();
 611     } else if (_range_ft > (_x_offset +_parent_x_offset)* 4
 612         ){
 613         SG_LOG(SG_GENERAL, SG_ALERT, "AIGroundVeh1cle: " << _name
 614             << " rescue: reforming train " << _range_ft
 615             );
 616
 617         setTowAngle(0, dt, 1);
 618         setSpeed(_parent_speed + (10 * sign(_parent_speed)));
 619
 620     } else if (_parent_speed > 1){
 621
 622         setTowSpeed();
 623         setTowAngle(_relbrg, dt, 1);
 624
 625     } else if (_parent_speed < -1){
 626
 627         setTowSpeed();
 628
 629         if (_relbrg < 0)
 630             setTowAngle(-(180 - (360 + _relbrg)), dt, 1);
 631         else
 632             setTowAngle(-(180 - _relbrg), dt, 1);
 633
 634     } else
 635         setSpeed(_parent_speed);
 636
 637 //    FGAIShip::update(_dt_count);
 638     _dt_count = 0;
 639
 640 }
 641
 642 // end AIGroundvehicle