1 // FGAIBallistic - FGAIBase-derived class creates a ballistic object
3 // Written by David Culp, started November 2003.
4 // - davidculp2@comcast.net
6 // With major additions by Mathias Froehlich & Vivian Meazza 2004-2008
8 // This program is free software; you can redistribute it and/or
9 // modify it under the terms of the GNU General Public License as
10 // published by the Free Software Foundation; either version 2 of the
11 // License, or (at your option) any later version.
13 // This program is distributed in the hope that it will be useful, but
14 // WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 // General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
26 #include <simgear/math/sg_random.h>
27 #include <simgear/math/sg_geodesy.hxx>
28 #include <simgear/scene/model/modellib.hxx>
30 #include <Scenery/scenery.hxx>
32 #include "AIBallistic.hxx"
34 #include <Main/util.hxx>
36 using namespace simgear;
38 const double FGAIBallistic::slugs_to_kgs = 14.5939029372;
39 const double FGAIBallistic::slugs_to_lbs = 32.1740485564;
41 FGAIBallistic::FGAIBallistic(object_type ot) :
49 _aero_stabilised(false),
52 _gravity(32.1740485564),
59 _force_stabilised(false),
61 _slave_load_to_ac(false),
63 _report_collision(false),
64 _report_impact(false),
65 _external_force(false),
66 _report_expiry(false),
67 _impact_report_node(fgGetNode("/ai/models/model-impact", true)),
76 FGAIBallistic::~FGAIBallistic() {
79 void FGAIBallistic::readFromScenario(SGPropertyNode* scFileNode) {
84 FGAIBase::readFromScenario(scFileNode);
86 //setPath(scFileNode->getStringValue("model", "Models/Geometry/rocket.ac"));
87 setRandom(scFileNode->getBoolValue("random", false));
88 setAzimuth(scFileNode->getDoubleValue("azimuth", 0.0));
89 setElevation(scFileNode->getDoubleValue("elevation", 0));
90 setDragArea(scFileNode->getDoubleValue("eda", 0.007));
91 setLife(scFileNode->getDoubleValue("life", 900.0));
92 setBuoyancy(scFileNode->getDoubleValue("buoyancy", 0));
93 //setWind_from_east(scFileNode->getDoubleValue("wind_from_east", 0));
94 //setWind_from_north(scFileNode->getDoubleValue("wind_from_north", 0));
95 setWind(scFileNode->getBoolValue("wind", false));
96 setRoll(scFileNode->getDoubleValue("roll", 0.0));
97 setCd(scFileNode->getDoubleValue("cd", 0.029));
98 //setMass(scFileNode->getDoubleValue("mass", 0.007));
99 setWeight(scFileNode->getDoubleValue("weight", 0.25));
100 setStabilisation(scFileNode->getBoolValue("aero-stabilised", false));
101 setNoRoll(scFileNode->getBoolValue("no-roll", false));
102 setImpact(scFileNode->getBoolValue("impact", false));
103 setExpiry(scFileNode->getBoolValue("expiry", false));
104 setCollision(scFileNode->getBoolValue("collision", false));
105 setImpactReportNode(scFileNode->getStringValue("impact-reports"));
106 setName(scFileNode->getStringValue("name", "Rocket"));
107 setFuseRange(scFileNode->getDoubleValue("fuse-range", 0.0));
108 setSMPath(scFileNode->getStringValue("submodel-path", ""));
109 setSubID(scFileNode->getIntValue("SubID", 0));
110 setExternalForce(scFileNode->getBoolValue("external-force", false));
111 setForcePath(scFileNode->getStringValue("force-path", ""));
112 setForceStabilisation(scFileNode->getBoolValue("force-stabilised", false));
113 setXoffset(scFileNode->getDoubleValue("x-offset", 0.0));
114 setYoffset(scFileNode->getDoubleValue("y-offset", 0.0));
115 setZoffset(scFileNode->getDoubleValue("z-offset", 0.0));
116 setPitchoffset(scFileNode->getDoubleValue("pitch-offset", 0.0));
117 setRolloffset(scFileNode->getDoubleValue("roll-offset", 0.0));
118 setYawoffset(scFileNode->getDoubleValue("yaw-offset", 0.0));
119 setGroundOffset(scFileNode->getDoubleValue("ground-offset", 0.0));
120 setLoadOffset(scFileNode->getDoubleValue("load-offset", 0.0));
121 setSlaved(scFileNode->getBoolValue("slaved", false));
122 setSlavedLoad(scFileNode->getBoolValue("slaved-load", false));
123 setContentsPath(scFileNode->getStringValue("contents"));
124 setParentName(scFileNode->getStringValue("parent"));
127 bool FGAIBallistic::init(bool search_in_AI_path) {
128 FGAIBase::init(search_in_AI_path);
130 _impact_reported = false;
131 _collision_reported = false;
132 _expiry_reported = false;
144 _elapsed_time += (sg_random() * 100);
146 props->setStringValue("material/name", "");
147 props->setStringValue("name", _name.c_str());
148 props->setStringValue("submodels/path", _path.c_str());
151 props->setStringValue("force/path", _force_path.c_str());
152 props->setStringValue("contents/path", _contents_path.c_str());
159 //setParentNodes(_selected_ac);
161 //props->setStringValue("vector/path", _vector_path.c_str());
163 // start with high value so that animations don't trigger yet
175 setParentNodes(_selected_ac);
180 void FGAIBallistic::bind() {
183 props->tie("sim/time/elapsed-sec",
184 SGRawValueMethods<FGAIBallistic,double>(*this,
185 &FGAIBallistic::_getTime));
186 //props->tie("mass-slug",
187 // SGRawValueMethods<FGAIBallistic,double>(*this,
188 // &FGAIBallistic::getMass));
190 props->tie("material/solid",
191 SGRawValuePointer<bool>(&_solid));
192 props->tie("altitude-agl-ft",
193 SGRawValuePointer<double>(&_ht_agl_ft));
194 props->tie("controls/slave-to-ac",
195 SGRawValueMethods<FGAIBallistic,bool>
196 (*this, &FGAIBallistic::getSlaved, &FGAIBallistic::setSlaved));
197 props->tie("controls/invisible",
198 SGRawValuePointer<bool>(&invisible));
200 if(_external_force || _slave_to_ac){
201 props->tie("controls/force_stabilized",
202 SGRawValuePointer<bool>(&_force_stabilised));
203 props->tie("position/global-x",
204 SGRawValueMethods<FGAIBase,double>(*this, &FGAIBase::_getCartPosX, 0));
205 props->tie("position/global-y",
206 SGRawValueMethods<FGAIBase,double>(*this, &FGAIBase::_getCartPosY, 0));
207 props->tie("position/global-z",
208 SGRawValueMethods<FGAIBase,double>(*this, &FGAIBase::_getCartPosZ, 0));
209 props->tie("velocities/vertical-speed-fps",
210 SGRawValuePointer<double>(&vs));
211 props->tie("velocities/true-airspeed-kt",
212 SGRawValuePointer<double>(&speed));
213 props->tie("velocities/horizontal-speed-fps",
214 SGRawValuePointer<double>(&hs));
215 props->tie("position/altitude-ft",
216 SGRawValueMethods<FGAIBase,double>(*this, &FGAIBase::_getElevationFt, &FGAIBase::_setAltitude));
217 props->tie("position/latitude-deg",
218 SGRawValueMethods<FGAIBase,double>(*this, &FGAIBase::_getLatitude, &FGAIBase::_setLatitude));
219 props->tie("position/longitude-deg",
220 SGRawValueMethods<FGAIBase,double>(*this, &FGAIBase::_getLongitude, &FGAIBase::_setLongitude));
221 props->tie("orientation/hdg-deg",
222 SGRawValuePointer<double>(&hdg));
223 props->tie("orientation/pitch-deg",
224 SGRawValuePointer<double>(&pitch));
225 props->tie("orientation/roll-deg",
226 SGRawValuePointer<double>(&roll));
227 props->tie("controls/slave-load-to-ac",
228 SGRawValueMethods<FGAIBallistic,bool>
229 (*this, &FGAIBallistic::getSlavedLoad, &FGAIBallistic::setSlavedLoad));
230 props->tie("position/load-offset",
231 SGRawValueMethods<FGAIBallistic,double>
232 (*this, &FGAIBallistic::getLoadOffset, &FGAIBallistic::setLoadOffset));
233 props->tie("load/distance-to-hitch-ft",
234 SGRawValueMethods<FGAIBallistic,double>
235 (*this, &FGAIBallistic::getDistanceToHitch));
236 props->tie("load/elevation-to-hitch-deg",
237 SGRawValueMethods<FGAIBallistic,double>
238 (*this, &FGAIBallistic::getElevToHitch));
239 props->tie("load/bearing-to-hitch-deg",
240 SGRawValueMethods<FGAIBallistic,double>
241 (*this, &FGAIBallistic::getBearingToHitch));
242 props->tie("material/load-resistance",
243 SGRawValuePointer<double>(&_load_resistance));
248 void FGAIBallistic::unbind() {
249 // FGAIBase::unbind();
251 props->untie("sim/time/elapsed-sec");
252 props->untie("mass-slug");
253 props->untie("material/solid");
254 props->untie("altitude-agl-ft");
255 props->untie("controls/slave-to-ac");
256 props->untie("controls/invisible");
258 if(_external_force || _slave_to_ac){
259 props->untie("position/global-y");
260 props->untie("position/global-x");
261 props->untie("position/global-z");
262 props->untie("velocities/vertical-speed-fps");
263 props->untie("velocities/true-airspeed-kt");
264 props->untie("velocities/horizontal-speed-fps");
265 props->untie("position/altitude-ft");
266 props->untie("position/latitude-deg");
267 props->untie("position/longitude-deg");
268 props->untie("position/ht-agl-ft");
269 props->untie("orientation/hdg-deg");
270 props->untie("orientation/pitch-deg");
271 props->untie("orientation/roll-deg");
272 props->untie("controls/force_stabilized");
273 props->untie("position/load-offset");
274 props->untie("load/distance-to-hitch-ft");
275 props->untie("load/elevation-to-hitch-deg");
276 props->untie("load/bearing-to-hitch-deg");
277 props->untie("material/load-resistance");
281 void FGAIBallistic::update(double dt) {
282 FGAIBase::update(dt);
288 } else if (!invisible){
295 void FGAIBallistic::setAzimuth(double az) {
298 hdg = _azimuth = (az - 5 ) + (10 * sg_random());
302 //cout << _name << " init hdg " << hdg << " random " << _random << endl;
305 void FGAIBallistic::setElevation(double el) {
306 pitch = _elevation = el;
309 void FGAIBallistic::setRoll(double rl) {
310 roll = _rotation = rl;
313 void FGAIBallistic::setStabilisation(bool val) {
314 _aero_stabilised = val;
317 void FGAIBallistic::setForceStabilisation(bool val) {
318 _force_stabilised = val;
321 void FGAIBallistic::setNoRoll(bool nr) {
325 void FGAIBallistic::setDragArea(double a) {
329 void FGAIBallistic::setLife(double seconds) {
332 life = seconds * _randomness + (seconds * (1 -_randomness) * sg_random());
333 //cout << "life " << life << endl;
338 void FGAIBallistic::setBuoyancy(double fpss) {
342 void FGAIBallistic::setWind_from_east(double fps) {
343 _wind_from_east = fps;
346 void FGAIBallistic::setWind_from_north(double fps) {
347 _wind_from_north = fps;
350 void FGAIBallistic::setWind(bool val) {
354 void FGAIBallistic::setCd(double c) {
358 void FGAIBallistic::setMass(double m) {
362 void FGAIBallistic::setWeight(double w) {
366 void FGAIBallistic::setRandomness(double r) {
370 void FGAIBallistic::setRandom(bool r) {
374 void FGAIBallistic::setImpact(bool i) {
378 void FGAIBallistic::setCollision(bool c) {
379 _report_collision = c;
382 void FGAIBallistic::setExpiry(bool e) {
386 void FGAIBallistic::setExternalForce(bool f) {
390 void FGAIBallistic::setImpactReportNode(const string& path) {
393 _impact_report_node = fgGetNode(path.c_str(), true);
396 void FGAIBallistic::setSMPath(const string& s) {
398 //cout << "submodel path " << _path << endl;
401 void FGAIBallistic::setFuseRange(double f) {
405 void FGAIBallistic::setSubID(int i) {
409 void FGAIBallistic::setSubmodel(const string& s) {
413 void FGAIBallistic::setGroundOffset(double g) {
417 void FGAIBallistic::setLoadOffset(double l) {
421 double FGAIBallistic::getLoadOffset() const {
425 void FGAIBallistic::setSlaved(bool s) {
429 void FGAIBallistic::setContentsPath(const string& path) {
431 _contents_path = path;
434 _contents_node = fgGetNode(path.c_str(), true);
438 void FGAIBallistic::setContentsNode(SGPropertyNode_ptr node) {
441 _contents_node = node;
442 _contents_path = _contents_node->getDisplayName();
446 void FGAIBallistic::setParentNodes(SGPropertyNode_ptr node) {
450 _p_pos_node = _pnode->getChild("position", 0, true);
451 _p_lat_node = _p_pos_node->getChild("latitude-deg", 0, true);
452 _p_lon_node = _p_pos_node->getChild("longitude-deg", 0, true);
453 _p_alt_node = _p_pos_node->getChild("altitude-ft", 0, true);
454 _p_agl_node = _p_pos_node->getChild("altitude-agl-ft", 0, true);
457 _p_ori_node = _pnode->getChild("orientation", 0, true);
458 _p_pch_node = _p_ori_node->getChild("pitch-deg", 0, true);
459 _p_rll_node = _p_ori_node->getChild("roll-deg", 0, true);
460 _p_hdg_node = _p_ori_node->getChild("true-heading-deg",0, true);
462 _p_vel_node = _pnode->getChild("velocities", 0, true);
463 _p_spd_node = _p_vel_node->getChild("true-airspeed-kt", 0, true);
468 void FGAIBallistic::setParentPos() {
471 //cout << "set parent pos" << endl;
473 double lat = _p_lat_node->getDoubleValue();
474 double lon = _p_lon_node->getDoubleValue();
475 double alt = _p_alt_node->getDoubleValue();
477 _parentpos.setLongitudeDeg(lon);
478 _parentpos.setLatitudeDeg(lat);
479 _parentpos.setElevationFt(alt);
485 bool FGAIBallistic::getSlaved() const {
489 double FGAIBallistic::getMass() const {
493 double FGAIBallistic::getContents() {
495 _contents_lb = _contents_node->getChild("level-lbs",0,1)->getDoubleValue();
500 void FGAIBallistic::setContents(double c) {
502 _contents_lb = _contents_node->getChild("level-gal_us",0,1)->setDoubleValue(c);
505 void FGAIBallistic::setSlavedLoad(bool l) {
506 _slave_load_to_ac = l;
509 bool FGAIBallistic::getSlavedLoad() const {
510 return _slave_load_to_ac;
513 void FGAIBallistic::setForcePath(const string& p) {
515 if (!_force_path.empty()) {
516 SGPropertyNode *fnode = fgGetNode(_force_path.c_str(), 0, true );
517 _force_node = fnode->getChild("force-lb", 0, true);
518 _force_azimuth_node = fnode->getChild("force-azimuth-deg", 0, true);
519 _force_elevation_node = fnode->getChild("force-elevation-deg", 0, true);
523 bool FGAIBallistic::getHtAGL(double start){
525 if (getGroundElevationM(SGGeod::fromGeodM(pos, start),
526 _elevation_m, &_material)) {
527 _ht_agl_ft = pos.getElevationFt() - _elevation_m * SG_METER_TO_FEET;
530 const vector<string>& names = _material->get_names();
531 _solid = _material->get_solid();
532 _load_resistance = _material->get_load_resistance();
533 _frictionFactor =_material->get_friction_factor();
536 props->setStringValue("material/name", names[0].c_str());
538 props->setStringValue("material/name", "");
540 _mat_name = names[0];
542 //cout << "material " << _mat_name
543 //<< " solid " << _solid
544 //<< " load " << _load_resistance
545 //<< " frictionFactor " << _frictionFactor
557 double FGAIBallistic::getRecip(double az){
558 // calculate the reciprocal of the input azimuth
566 void FGAIBallistic::setPch(double e, double dt, double coeff){
567 double c = dt / (coeff + dt);
568 pitch = (e * c) + (pitch * (1 - c));
571 void FGAIBallistic::setBnk(double r, double dt, double coeff){
572 double c = dt / (coeff + dt);
573 roll = (r * c) + (roll * (1 - c));
576 void FGAIBallistic::setSpd(double s, double dt, double coeff){
577 double c = dt / (coeff + dt);
578 _speed = (s * c) + (_speed * (1 - c));
581 void FGAIBallistic::setHt(double h, double dt, double coeff){
582 double c = dt / (coeff + dt);
583 _height = (h * c) + (_height * (1 - c));
586 int FGAIBallistic::setHdg(double tgt_hdg, double dt, double coeff){
587 double recip = getRecip(hdg);
588 double c = dt / (coeff + dt);
589 //we need to ensure that we turn the short way to the new hdg
590 if (tgt_hdg < recip && tgt_hdg < hdg && hdg > 180) {
591 hdg = ((tgt_hdg + 360) * c) + (hdg * (1 - c));
592 // cout << "case 1: right turn" << endl;
593 } else if (tgt_hdg > recip && tgt_hdg > hdg && hdg <= 180){
594 hdg = ((tgt_hdg - 360) * c) + (hdg * (1 - c));
595 // cout << "case 2: left turn" << endl;
597 hdg = (tgt_hdg * c) + (hdg * (1 - c));
598 // cout << "case 4: left turn" << endl;
603 double FGAIBallistic::getTgtXOffset() const {
604 return _tgt_x_offset;
607 double FGAIBallistic::getTgtYOffset() const {
608 return _tgt_y_offset;
611 double FGAIBallistic::getTgtZOffset() const {
612 return _tgt_z_offset;
615 void FGAIBallistic::setTgtXOffset(double x){
619 void FGAIBallistic::setTgtYOffset(double y){
623 void FGAIBallistic::setTgtZOffset(double z){
627 void FGAIBallistic::slaveToAC(double dt){
629 double hdg, pch, rll, agl = 0;
633 hdg = _p_hdg_node->getDoubleValue();
634 pch = _p_pch_node->getDoubleValue();
635 rll = _p_rll_node->getDoubleValue();
636 agl = _p_agl_node->getDoubleValue();
637 setOffsetPos(_parentpos, hdg, pch, rll);
638 setSpeed(_p_spd_node->getDoubleValue());
640 hdg = manager->get_user_heading();
641 pch = manager->get_user_pitch();
642 rll = manager->get_user_roll();
643 agl = manager->get_user_agl();
644 setOffsetPos(userpos, hdg, pch, rll);
645 setSpeed(manager->get_user_speed());
648 pos.setLatitudeDeg(_offsetpos.getLatitudeDeg());
649 pos.setLongitudeDeg(_offsetpos.getLongitudeDeg());
650 pos.setElevationFt(_offsetpos.getElevationFt());
652 setPitch(pch + _pitch_offset);
653 setBank(rll + _roll_offset);
654 setOffsetVelocity(dt, pos);
656 //update the mass (slugs)
657 _mass = (_weight_lb + getContents()) / slugs_to_lbs;
659 _impact_reported = false;
661 //cout << _name << " _mass "<<_mass <<" " << getContents()
662 //<< " " << getContents() / slugs_to_lbs << " weight " << _weight_lb << endl;
663 // cout << _name << " update hs " << hs << " vs " << vs << endl;
666 void FGAIBallistic::Run(double dt) {
669 // if life = -1 the object does not die
670 if (_life_timer > life && life != -1){
672 if (_report_expiry && !_expiry_reported && !_impact_reported && !_collision_reported){
673 //cout<<"AIBallistic: expiry"<< endl;
680 //set the contents in the appropriate tank or other property in the parent to zero
683 //randomise Cd by +- 10%
685 _Cd = _Cd * 0.90 + (0.10 * sg_random());
687 // Adjust Cd by Mach number. The equations are based on curves
688 // for a conventional shell/bullet (no boat-tail).
692 Cdm = 0.0125 * Mach + _Cd;
693 else if (Mach < 1.2 )
694 Cdm = 0.3742 * pow(Mach, 2) - 0.252 * Mach + 0.0021 + _Cd;
696 Cdm = 0.2965 * pow(Mach, -1.1506) + _Cd;
698 //cout <<_name << " Mach " << Mach << " Cdm " << Cdm
699 // << " ballistic speed kts "<< speed << endl;
701 // drag = Cd * 0.5 * rho * speed * speed * drag_area;
702 // rho is adjusted for altitude in void FGAIBase::update,
703 // using Standard Atmosphere (sealevel temperature 15C)
704 // acceleration = drag/mass;
705 // adjust speed by drag
706 speed -= (Cdm * 0.5 * rho * speed * speed * _drag_area/_mass) * dt;
708 // don't let speed become negative
712 double speed_fps = speed * SG_KT_TO_FPS;
715 // calculate vertical and horizontal speed components
719 vs = sin( _elevation * SG_DEGREES_TO_RADIANS ) * speed_fps;
720 hs = cos( _elevation * SG_DEGREES_TO_RADIANS ) * speed_fps;
723 //resolve horizontal speed into north and east components:
724 double speed_north_fps = cos(_azimuth / SG_RADIANS_TO_DEGREES) * hs;
725 double speed_east_fps = sin(_azimuth / SG_RADIANS_TO_DEGREES) * hs;
727 // convert horizontal speed (fps) to degrees per second
728 double speed_north_deg_sec = speed_north_fps / ft_per_deg_lat;
729 double speed_east_deg_sec = speed_east_fps / ft_per_deg_lon;
731 // if wind not required, set to zero
733 _wind_from_north = 0;
736 _wind_from_north = manager->get_wind_from_north();
737 _wind_from_east = manager->get_wind_from_east();
740 //calculate velocity due to external force
741 double force_speed_north_deg_sec = 0;
742 double force_speed_east_deg_sec = 0;
743 // double vs_force_fps = 0;
744 double hs_force_fps = 0;
745 double v_force_acc_fpss = 0;
746 double force_speed_north_fps = 0;
747 double force_speed_east_fps = 0;
748 double h_force_lbs = 0;
749 double normal_force_lbs = 0;
750 double normal_force_fpss = 0;
751 double static_friction_force_lbs = 0;
752 double dynamic_friction_force_lbs = 0;
753 double friction_force_speed_north_fps = 0;
754 double friction_force_speed_east_fps = 0;
755 double friction_force_speed_north_deg_sec = 0;
756 double friction_force_speed_east_deg_sec = 0;
757 double force_elevation_deg = 0;
759 if (_external_force) {
760 //cout << _name << " external force" << endl;
762 SGPropertyNode *n = fgGetNode(_force_path.c_str(), true);
763 double force_lbs = n->getChild("force-lb", 0, true)->getDoubleValue();
764 force_elevation_deg = n->getChild("force-elevation-deg", 0, true)->getDoubleValue();
765 double force_azimuth_deg = n->getChild("force-azimuth-deg", 0, true)->getDoubleValue();
767 //resolve force into vertical and horizontal components:
768 double v_force_lbs = force_lbs * sin( force_elevation_deg * SG_DEGREES_TO_RADIANS );
769 h_force_lbs = force_lbs * cos( force_elevation_deg * SG_DEGREES_TO_RADIANS );
773 if (getHtAGL(10000)){
774 double deadzone = 0.1;
776 if (_ht_agl_ft <= (0 + _ground_offset + deadzone) && _solid){
777 normal_force_lbs = (_mass * slugs_to_lbs) - v_force_lbs;
779 if ( normal_force_lbs < 0 )
780 normal_force_lbs = 0;
782 pos.setElevationFt(0 + _ground_offset);
786 // calculate friction
787 // we assume a static Coefficient of Friction (mu) of 0.62 (wood on concrete)
790 static_friction_force_lbs = mu * normal_force_lbs * _frictionFactor;
792 //adjust horizontal force. We assume that a speed of <= 5 fps is static
793 if (h_force_lbs <= static_friction_force_lbs && hs <= 5){
794 h_force_lbs = hs = 0;
795 speed_north_fps = speed_east_fps = 0;
797 dynamic_friction_force_lbs = (static_friction_force_lbs * 0.95);
799 //ignore wind when on the ground for now
801 _wind_from_north = 0;
808 //acceleration = (force(lbsf)/mass(slugs))
809 v_force_acc_fpss = v_force_lbs/_mass;
810 normal_force_fpss = normal_force_lbs/_mass;
811 double h_force_acc_fpss = h_force_lbs/_mass;
812 double dynamic_friction_acc_fpss = dynamic_friction_force_lbs/_mass;
814 // velocity = acceleration * dt
815 hs_force_fps = h_force_acc_fpss * dt;
816 double friction_force_fps = dynamic_friction_acc_fpss * dt;
818 //resolve horizontal speeds into north and east components:
819 force_speed_north_fps = cos(force_azimuth_deg * SG_DEGREES_TO_RADIANS) * hs_force_fps;
820 force_speed_east_fps = sin(force_azimuth_deg * SG_DEGREES_TO_RADIANS) * hs_force_fps;
822 friction_force_speed_north_fps = cos(getRecip(hdg) * SG_DEGREES_TO_RADIANS) * friction_force_fps;
823 friction_force_speed_east_fps = sin(getRecip(hdg) * SG_DEGREES_TO_RADIANS) * friction_force_fps;
825 // convert horizontal speed (fps) to degrees per second
826 force_speed_north_deg_sec = force_speed_north_fps / ft_per_deg_lat;
827 force_speed_east_deg_sec = force_speed_east_fps / ft_per_deg_lon;
829 friction_force_speed_north_deg_sec = friction_force_speed_north_fps / ft_per_deg_lat;
830 friction_force_speed_east_deg_sec = friction_force_speed_east_fps / ft_per_deg_lon;
833 // convert wind speed (fps) to degrees lat/lon per second
834 double wind_speed_from_north_deg_sec = _wind_from_north / ft_per_deg_lat;
835 double wind_speed_from_east_deg_sec = _wind_from_east / ft_per_deg_lon;
837 //recombine the horizontal velocity components
838 hs = sqrt(((speed_north_fps + force_speed_north_fps + friction_force_speed_north_fps)
839 * (speed_north_fps + force_speed_north_fps + friction_force_speed_north_fps))
840 + ((speed_east_fps + force_speed_east_fps + friction_force_speed_east_fps)
841 * (speed_east_fps + force_speed_east_fps + friction_force_speed_east_fps)));
846 // adjust vertical speed for acceleration of gravity, buoyancy, and vertical force
847 vs -= (_gravity - _buoyancy - v_force_acc_fpss - normal_force_fpss) * dt;
849 if (vs <= 0.00001 && vs >= -0.00001)
853 if(_slave_load_to_ac) {
855 manager->get_user_heading(),
856 manager->get_user_pitch(),
857 manager->get_user_roll()
859 pos.setLatitudeDeg(_offsetpos.getLatitudeDeg());
860 pos.setLongitudeDeg(_offsetpos.getLongitudeDeg());
861 pos.setElevationFt(_offsetpos.getElevationFt());
863 if (getHtAGL(10000)){
864 double deadzone = 0.1;
866 if (_ht_agl_ft <= (0 + _ground_offset + deadzone) && _solid){
867 pos.setElevationFt(0 + _ground_offset);
869 pos.setElevationFt(_offsetpos.getElevationFt() + _load_offset);
874 pos.setLatitudeDeg( pos.getLatitudeDeg()
875 + (speed_north_deg_sec - wind_speed_from_north_deg_sec
876 + force_speed_north_deg_sec + friction_force_speed_north_deg_sec) * dt );
877 pos.setLongitudeDeg( pos.getLongitudeDeg()
878 + (speed_east_deg_sec - wind_speed_from_east_deg_sec
879 + force_speed_east_deg_sec + friction_force_speed_east_deg_sec) * dt );
880 pos.setElevationFt(pos.getElevationFt() + vs * dt);
883 // cout << _name << " run hs " << hs << " vs " << vs << endl;
885 // recalculate total speed
886 if ( vs == 0 && hs == 0)
889 speed = sqrt( vs * vs + hs * hs) / SG_KT_TO_FPS;
891 // recalculate elevation and azimuth (velocity vectors)
892 _elevation = atan2( vs, hs ) * SG_RADIANS_TO_DEGREES;
893 _azimuth = atan2((speed_east_fps + force_speed_east_fps + friction_force_speed_east_fps),
894 (speed_north_fps + force_speed_north_fps + friction_force_speed_north_fps))
895 * SG_RADIANS_TO_DEGREES;
897 // rationalise azimuth
901 if (_aero_stabilised) { // we simulate rotational moment of inertia by using a filter
902 //cout<< "_aero_stabilised "<< endl;
903 const double coeff = 0.9;
905 // we assume a symetrical MI about the pitch and yaw axis
906 setPch(_elevation, dt, coeff);
907 setHdg(_azimuth, dt, coeff);
908 } else if (_force_stabilised) { // we simulate rotational moment of inertia by using a filter
909 //cout<< "_force_stabilised "<< endl;
911 const double coeff = 0.9;
912 double ratio = h_force_lbs/(_mass * slugs_to_lbs);
914 if (ratio > 1) ratio = 1;
915 if (ratio < -1) ratio = -1;
917 double force_pitch = acos(ratio) * SG_RADIANS_TO_DEGREES;
919 if (force_pitch <= force_elevation_deg)
920 force_pitch = force_elevation_deg;
922 // we assume a symetrical MI about the pitch and yaw axis
923 setPch(force_pitch,dt, coeff);
924 setHdg(_azimuth, dt, coeff);
927 //do impacts and collisions
928 if (_report_impact && !_impact_reported)
931 if (_report_collision && !_collision_reported)
934 // set destruction flag if altitude less than sea level -1000
935 if (altitude_ft < -1000.0 && life != -1)
940 double FGAIBallistic::_getTime() const {
944 void FGAIBallistic::handle_impact() {
946 // try terrain intersection
947 double start = pos.getElevationM() + 10;
952 if (_ht_agl_ft <= 0) {
953 SG_LOG(SG_GENERAL, SG_DEBUG, "AIBallistic: terrain impact");
954 report_impact(_elevation_m);
955 _impact_reported = true;
959 } else if (_subID == 0) // kill the AIObject if there is no subsubmodel
964 void FGAIBallistic::handle_expiry() {
966 SG_LOG(SG_GENERAL, SG_DEBUG, "AIBallistic: handle_expiry " << pos.getElevationM());
968 report_impact(pos.getElevationM());
969 _expiry_reported = true;
973 } else if (_subID == 0){ // kill the AIObject if there is no subsubmodel
979 void FGAIBallistic::handle_collision()
981 const FGAIBase *object = manager->calcCollision(pos.getElevationFt(),
982 pos.getLatitudeDeg(),pos.getLongitudeDeg(), _fuse_range);
985 report_impact(pos.getElevationM(), object);
986 _collision_reported = true;
990 void FGAIBallistic::report_impact(double elevation, const FGAIBase *object)
992 _impact_lat = pos.getLatitudeDeg();
993 _impact_lon = pos.getLongitudeDeg();
994 _impact_elev = elevation;
995 _impact_speed = speed * SG_KT_TO_MPS;
997 _impact_pitch = pitch;
1000 SGPropertyNode *n = props->getNode("impact", true);
1003 n->setStringValue("type", object->getTypeString());
1005 n->setStringValue("type", "terrain");
1007 SG_LOG(SG_GENERAL, SG_DEBUG, "AIBallistic: object impact" << _name << " lon " <<_impact_lon);
1009 n->setDoubleValue("longitude-deg", _impact_lon);
1010 n->setDoubleValue("latitude-deg", _impact_lat);
1011 n->setDoubleValue("elevation-m", _impact_elev);
1012 n->setDoubleValue("heading-deg", _impact_hdg);
1013 n->setDoubleValue("pitch-deg", _impact_pitch);
1014 n->setDoubleValue("roll-deg", _impact_roll);
1015 n->setDoubleValue("speed-mps", _impact_speed);
1017 _impact_report_node->setStringValue(props->getPath());
1020 SGVec3d FGAIBallistic::getCartUserPos() const {
1021 SGVec3d cartUserPos = SGVec3d::fromGeod(userpos);
1025 SGVec3d FGAIBallistic::getCartHitchPos() const{
1027 // convert geodetic positions to geocentered
1028 SGVec3d cartuserPos = SGVec3d::fromGeod(userpos);
1029 //SGVec3d cartPos = getCartPos();
1031 // Transform to the right coordinate frame, configuration is done in
1032 // the x-forward, y-right, z-up coordinates (feet), computation
1033 // in the simulation usual body x-forward, y-right, z-down coordinates
1035 SGVec3d _off(_x_offset * SG_FEET_TO_METER,
1036 _y_offset * SG_FEET_TO_METER,
1037 -_z_offset * SG_FEET_TO_METER);
1039 // Transform the user position to the horizontal local coordinate system.
1040 SGQuatd hlTrans = SGQuatd::fromLonLat(userpos);
1042 // and postrotate the orientation of the user model wrt the horizontal
1044 hlTrans *= SGQuatd::fromYawPitchRollDeg(
1045 manager->get_user_heading(),
1046 manager->get_user_pitch(),
1047 manager->get_user_roll());
1049 // The offset converted to the usual body fixed coordinate system
1050 // rotated to the earth-fixed coordinates axis
1051 SGVec3d off = hlTrans.backTransform(_off);
1053 // Add the position offset of the user model to get the geocentered position
1054 SGVec3d offsetPos = cartuserPos + off;
1059 void FGAIBallistic::setOffsetPos(SGGeod inpos, double heading, double pitch, double roll){
1060 // convert the hitch geocentered position to geodetic
1062 SGVec3d cartoffsetPos = getCartOffsetPos(inpos, heading, pitch, roll);
1064 //SGVec3d cartoffsetPos = getCartHitchPos();
1066 //SGGeodesy::SGCartToGeod(cartoffsetPos, hitchpos);
1067 SGGeodesy::SGCartToGeod(cartoffsetPos, _offsetpos);
1071 double FGAIBallistic::getDistanceToHitch() const {
1072 //calculate the distance load to hitch
1073 SGVec3d carthitchPos = getCartHitchPos();
1074 SGVec3d cartPos = getCartPos();
1076 SGVec3d diff = carthitchPos - cartPos;
1077 double distance = norm(diff);
1078 return distance * SG_METER_TO_FEET;
1081 double FGAIBallistic::getElevToHitch() const {
1082 // now the angle, positive angles are upwards
1083 double distance = getDistanceToHitch() * SG_FEET_TO_METER;
1085 double daltM = _offsetpos.getElevationM() - pos.getElevationM();
1087 if (fabs(distance) < SGLimits<float>::min()) {
1090 double sAngle = daltM/distance;
1091 sAngle = SGMiscd::min(1, SGMiscd::max(-1, sAngle));
1092 angle = SGMiscd::rad2deg(asin(sAngle));
1098 double FGAIBallistic::getBearingToHitch() const {
1099 //calculate the bearing and range of the second pos from the first
1100 double distance = getDistanceToHitch() * SG_FEET_TO_METER;
1103 geo_inverse_wgs_84(pos, _offsetpos, &az1, &az2, &distance);
1108 double FGAIBallistic::getRelBrgHitchToUser() const {
1109 //calculate the relative bearing
1110 double az1, az2, distance;
1112 geo_inverse_wgs_84(_offsetpos, userpos, &az1, &az2, &distance);
1114 double rel_brg = az1 - hdg;
1116 SG_NORMALIZE_RANGE(rel_brg, -180.0, 180.0);
1121 double FGAIBallistic::getElevHitchToUser() const {
1123 //calculate the distance from the user position
1124 SGVec3d carthitchPos = getCartHitchPos();
1125 SGVec3d cartuserPos = getCartUserPos();
1127 SGVec3d diff = cartuserPos - carthitchPos;
1129 double distance = norm(diff);
1132 double daltM = userpos.getElevationM() - _offsetpos.getElevationM();
1134 // now the angle, positive angles are upwards
1135 if (fabs(distance) < SGLimits<float>::min()) {
1138 double sAngle = daltM/distance;
1139 sAngle = SGMiscd::min(1, SGMiscd::max(-1, sAngle));
1140 angle = SGMiscd::rad2deg(asin(sAngle));
1146 void FGAIBallistic::setTgtOffsets(double dt, double coeff){
1147 double c = dt / (coeff + dt);
1149 _x_offset = (_tgt_x_offset * c) + (_x_offset * (1 - c));
1150 _y_offset = (_tgt_y_offset * c) + (_y_offset * (1 - c));
1151 _z_offset = (_tgt_z_offset * c) + (_z_offset * (1 - c));
1155 void FGAIBallistic::calcVSHS(){
1156 // calculate vertical and horizontal speed components
1157 double speed_fps = speed * SG_KT_TO_FPS;
1162 vs = sin( _elevation * SG_DEGREES_TO_RADIANS ) * speed_fps;
1163 hs = cos( _elevation * SG_DEGREES_TO_RADIANS ) * speed_fps;
1167 void FGAIBallistic::calcNE(){
1168 //resolve horizontal speed into north and east components:
1169 _speed_north_fps = cos(_azimuth / SG_RADIANS_TO_DEGREES) * hs;
1170 _speed_east_fps = sin(_azimuth / SG_RADIANS_TO_DEGREES) * hs;
1172 // convert horizontal speed (fps) to degrees per second
1173 speed_north_deg_sec = _speed_north_fps / ft_per_deg_lat;
1174 speed_east_deg_sec = _speed_east_fps / ft_per_deg_lon;
1178 SGVec3d FGAIBallistic::getCartOffsetPos(SGGeod inpos, double user_heading,
1179 double user_pitch, double user_roll
1182 // convert geodetic positions to geocentered
1183 SGVec3d cartuserPos = SGVec3d::fromGeod(inpos);
1184 //SGVec3d cartuserPos = getCartUserPos();
1185 //SGVec3d cartPos = getCartPos();
1187 // Transform to the right coordinate frame, configuration is done in
1188 // the x-forward, y-right, z-up coordinates (feet), computation
1189 // in the simulation usual body x-forward, y-right, z-down coordinates
1191 SGVec3d _off(_x_offset * SG_FEET_TO_METER,
1192 _y_offset * SG_FEET_TO_METER,
1193 -_z_offset * SG_FEET_TO_METER);
1195 // Transform the user position to the horizontal local coordinate system.
1196 SGQuatd hlTrans = SGQuatd::fromLonLat(inpos);
1198 // and postrotate the orientation of the user model wrt the horizontal
1200 hlTrans *= SGQuatd::fromYawPitchRollDeg(
1205 // The offset converted to the usual body fixed coordinate system
1206 // rotated to the earth-fixed coordinates axis
1207 SGVec3d off = hlTrans.backTransform(_off);
1209 // Add the position offset of the user model to get the geocentered position
1210 SGVec3d offsetPos = cartuserPos + off;
1215 void FGAIBallistic::setOffsetVelocity(double dt, SGGeod offsetpos) {
1216 //calculate the distance from the previous offset position
1217 SGVec3d cartoffsetPos = SGVec3d::fromGeod(offsetpos);
1218 SGVec3d diff = cartoffsetPos - _oldcartoffsetPos;
1220 double distance = norm(diff);
1221 //calculate speed knots
1222 speed = (distance/dt) * SG_MPS_TO_KT;
1224 //now calulate the angle between the old and current postion positions (degrees)
1226 double daltM = offsetpos.getElevationM() - _oldoffsetpos.getElevationM();
1228 if (fabs(distance) < SGLimits<float>::min()) {
1231 double sAngle = daltM/distance;
1232 sAngle = SGMiscd::min(1, SGMiscd::max(-1, sAngle));
1233 angle = SGMiscd::rad2deg(asin(sAngle));
1238 //calculate vertical and horizontal speed components
1241 //calculate the bearing of the new offset position from the old
1242 double az1, az2, dist;
1243 geo_inverse_wgs_84(_oldoffsetpos, offsetpos, &az1, &az2, &dist);
1246 //resolve horizontal speed into north and east components:
1249 // and finally store the new values
1250 _oldcartoffsetPos = cartoffsetPos;
1251 _oldoffsetpos = offsetpos;