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) :
44 _aero_stabilised(false),
47 _gravity(32.1740485564),
53 _report_collision(false),
54 _report_impact(false),
56 _impact_report_node(fgGetNode("/ai/models/model-impact", true)),
57 _force_stabilised(false),
58 _external_force(false),
60 _slave_load_to_ac(false),
61 _formate_to_ac(false),
71 FGAIBallistic::~FGAIBallistic() {
74 void FGAIBallistic::readFromScenario(SGPropertyNode* scFileNode) {
79 FGAIBase::readFromScenario(scFileNode);
81 //setPath(scFileNode->getStringValue("model", "Models/Geometry/rocket.ac"));
82 setAzimuth(scFileNode->getDoubleValue("azimuth", 0.0));
83 setElevation(scFileNode->getDoubleValue("elevation", 0));
84 setDragArea(scFileNode->getDoubleValue("eda", 0.007));
85 setLife(scFileNode->getDoubleValue("life", 900.0));
86 setBuoyancy(scFileNode->getDoubleValue("buoyancy", 0));
87 setWind_from_east(scFileNode->getDoubleValue("wind_from_east", 0));
88 setWind_from_north(scFileNode->getDoubleValue("wind_from_north", 0));
89 setWind(scFileNode->getBoolValue("wind", false));
90 setRoll(scFileNode->getDoubleValue("roll", 0.0));
91 setCd(scFileNode->getDoubleValue("cd", 0.029));
92 //setMass(scFileNode->getDoubleValue("mass", 0.007));
93 setWeight(scFileNode->getDoubleValue("weight", 0.25));
94 setStabilisation(scFileNode->getBoolValue("aero-stabilized", false));
95 setNoRoll(scFileNode->getBoolValue("no-roll", false));
96 setRandom(scFileNode->getBoolValue("random", false));
97 setImpact(scFileNode->getBoolValue("impact", false));
98 setImpactReportNode(scFileNode->getStringValue("impact-reports"));
99 setName(scFileNode->getStringValue("name", "Rocket"));
100 setFuseRange(scFileNode->getDoubleValue("fuse-range", 0.0));
101 setSMPath(scFileNode->getStringValue("submodel-path", ""));
102 setSubID(scFileNode->getIntValue("SubID", 0));
103 setExternalForce(scFileNode->getBoolValue("external-force", false));
104 setForcePath(scFileNode->getStringValue("force-path", ""));
105 setForceStabilisation(scFileNode->getBoolValue("force-stabilized", false));
106 setXoffset(scFileNode->getDoubleValue("x-offset", 0.0));
107 setYoffset(scFileNode->getDoubleValue("y-offset", 0.0));
108 setZoffset(scFileNode->getDoubleValue("z-offset", 0.0));
109 setPitchoffset(scFileNode->getDoubleValue("pitch-offset", 0.0));
110 setRolloffset(scFileNode->getDoubleValue("roll-offset", 0.0));
111 setYawoffset(scFileNode->getDoubleValue("yaw-offset", 0.0));
112 setGroundOffset(scFileNode->getDoubleValue("ground-offset", 0.0));
113 setLoadOffset(scFileNode->getDoubleValue("load-offset", 0.0));
114 setSlaved(scFileNode->getBoolValue("slaved", false));
115 setSlavedLoad(scFileNode->getBoolValue("slaved-load", false));
116 setContentsNode(scFileNode->getStringValue("contents"));
117 setRandom(scFileNode->getBoolValue("random", false));
120 bool FGAIBallistic::init(bool search_in_AI_path) {
121 FGAIBase::init(search_in_AI_path);
123 _impact_reported = false;
124 _collision_reported = false;
127 _elapsed_time += (sg_random() * 100);
129 props->setStringValue("material/name", "");
130 props->setStringValue("name", _name.c_str());
131 props->setStringValue("submodels/path", _submodel.c_str());
133 // start with high value so that animations don't trigger yet
144 void FGAIBallistic::bind() {
147 props->tie("sim/time/elapsed-sec",
148 SGRawValueMethods<FGAIBallistic,double>(*this,
149 &FGAIBallistic::_getTime));
150 props->tie("mass-slug",
151 SGRawValueMethods<FGAIBallistic,double>(*this,
152 &FGAIBallistic::getMass));
153 props->tie("material/load-resistance",
154 SGRawValuePointer<double>(&_load_resistance));
155 props->tie("material/solid",
156 SGRawValuePointer<bool>(&_solid));
157 props->tie("altitude-agl-ft",
158 SGRawValuePointer<double>(&_ht_agl_ft));
159 props->tie("controls/slave-to-ac",
160 SGRawValueMethods<FGAIBallistic,bool>
161 (*this, &FGAIBallistic::getSlaved, &FGAIBallistic::setSlaved));
162 props->tie("controls/invisible",
163 SGRawValuePointer<bool>(&invisible));
166 props->tie("controls/force_stabilized",
167 SGRawValuePointer<bool>(&_force_stabilised));
168 props->tie("position/global-x",
169 SGRawValueMethods<FGAIBase,double>(*this, &FGAIBase::_getCartPosX, 0));
170 props->tie("position/global-y",
171 SGRawValueMethods<FGAIBase,double>(*this, &FGAIBase::_getCartPosY, 0));
172 props->tie("position/global-z",
173 SGRawValueMethods<FGAIBase,double>(*this, &FGAIBase::_getCartPosZ, 0));
174 props->tie("velocities/vertical-speed-fps",
175 SGRawValuePointer<double>(&vs));
176 props->tie("velocities/true-airspeed-kt",
177 SGRawValuePointer<double>(&speed));
178 props->tie("velocities/horizontal-speed-fps",
179 SGRawValuePointer<double>(&hs));
180 props->tie("position/altitude-ft",
181 SGRawValueMethods<FGAIBase,double>(*this, &FGAIBase::_getAltitude, &FGAIBase::_setAltitude));
182 props->tie("position/latitude-deg",
183 SGRawValueMethods<FGAIBase,double>(*this, &FGAIBase::_getLatitude, &FGAIBase::_setLatitude));
184 props->tie("position/longitude-deg",
185 SGRawValueMethods<FGAIBase,double>(*this, &FGAIBase::_getLongitude, &FGAIBase::_setLongitude));
186 props->tie("orientation/hdg-deg",
187 SGRawValuePointer<double>(&hdg));
188 props->tie("orientation/pitch-deg",
189 SGRawValuePointer<double>(&pitch));
190 props->tie("orientation/roll-deg",
191 SGRawValuePointer<double>(&roll));
192 props->tie("controls/slave-load-to-ac",
193 SGRawValueMethods<FGAIBallistic,bool>
194 (*this, &FGAIBallistic::getSlavedLoad, &FGAIBallistic::setSlavedLoad));
195 props->tie("position/load-offset",
196 SGRawValueMethods<FGAIBallistic,double>
197 (*this, &FGAIBallistic::getLoadOffset, &FGAIBallistic::setLoadOffset));
198 props->tie("load/distance-to-hitch-ft",
199 SGRawValueMethods<FGAIBallistic,double>
200 (*this, &FGAIBallistic::getDistanceLoadToHitch));
201 props->tie("load/elevation-to-hitch-deg",
202 SGRawValueMethods<FGAIBallistic,double>
203 (*this, &FGAIBallistic::getElevLoadToHitch));
204 props->tie("load/bearing-to-hitch-deg",
205 SGRawValueMethods<FGAIBallistic,double>
206 (*this, &FGAIBallistic::getBearingLoadToHitch));
211 void FGAIBallistic::unbind() {
212 // FGAIBase::unbind();
214 props->untie("sim/time/elapsed-sec");
215 props->untie("mass-slug");
216 props->untie("material/load-resistance");
217 props->untie("material/solid");
218 props->untie("altitude-agl-ft");
219 props->untie("controls/slave-to-ac");
220 props->untie("controls/invisible");
223 props->untie("position/global-y");
224 props->untie("position/global-x");
225 props->untie("position/global-z");
226 props->untie("velocities/vertical-speed-fps");
227 props->untie("velocities/true-airspeed-kt");
228 props->untie("velocities/horizontal-speed-fps");
229 props->untie("position/altitude-ft");
230 props->untie("position/latitude-deg");
231 props->untie("position/longitude-deg");
232 props->untie("position/ht-agl-ft");
233 props->untie("orientation/hdg-deg");
234 props->untie("orientation/pitch-deg");
235 props->untie("orientation/roll-deg");
236 props->untie("controls/force_stabilized");
237 props->untie("position/load-offset");
238 props->untie("load/distance-to-hitch-ft");
239 props->untie("load/elevation-to-hitch-deg");
240 props->untie("load/bearing-to-hitch-deg");
244 void FGAIBallistic::update(double dt) {
245 FGAIBase::update(dt);
251 setHitchVelocity(dt);
252 } else if (_formate_to_ac){
255 setHitchVelocity(dt);
256 } else if (!invisible){
263 void FGAIBallistic::setAzimuth(double az) {
267 void FGAIBallistic::setElevation(double el) {
268 pitch = _elevation = el;
271 void FGAIBallistic::setRoll(double rl) {
272 roll = _rotation = rl;
275 void FGAIBallistic::setStabilisation(bool val) {
276 _aero_stabilised = val;
279 void FGAIBallistic::setForceStabilisation(bool val) {
280 _force_stabilised = val;
283 void FGAIBallistic::setNoRoll(bool nr) {
287 void FGAIBallistic::setDragArea(double a) {
291 void FGAIBallistic::setLife(double seconds) {
295 void FGAIBallistic::setBuoyancy(double fpss) {
299 void FGAIBallistic::setWind_from_east(double fps) {
300 _wind_from_east = fps;
303 void FGAIBallistic::setWind_from_north(double fps) {
304 _wind_from_north = fps;
307 void FGAIBallistic::setWind(bool val) {
311 void FGAIBallistic::setCd(double c) {
315 void FGAIBallistic::setMass(double m) {
319 void FGAIBallistic::setWeight(double w) {
322 void FGAIBallistic::setRandom(bool r) {
326 void FGAIBallistic::setImpact(bool i) {
330 void FGAIBallistic::setCollision(bool c) {
331 _report_collision = c;
334 void FGAIBallistic::setExternalForce(bool f) {
338 void FGAIBallistic::setImpactReportNode(const string& path) {
341 _impact_report_node = fgGetNode(path.c_str(), true);
344 void FGAIBallistic::setName(const string& n) {
348 void FGAIBallistic::setSMPath(const string& s) {
352 void FGAIBallistic::setFuseRange(double f) {
356 void FGAIBallistic::setSubID(int i) {
360 void FGAIBallistic::setSubmodel(const string& s) {
364 void FGAIBallistic::setGroundOffset(double g) {
368 void FGAIBallistic::setLoadOffset(double l) {
372 double FGAIBallistic::getLoadOffset() const {
376 void FGAIBallistic::setSlaved(bool s) {
380 void FGAIBallistic::setFormate(bool f) {
384 void FGAIBallistic::setContentsNode(const string& path) {
386 _contents_node = fgGetNode(path.c_str(), true);
390 bool FGAIBallistic::getSlaved() const {
394 double FGAIBallistic::getMass() const {
398 double FGAIBallistic::getContents() {
400 _contents_lb = _contents_node->getChild("level-lbs",0,1)->getDoubleValue();
404 void FGAIBallistic::setContents(double c) {
406 _contents_lb = _contents_node->getChild("level-gal_us",0,1)->setDoubleValue(c);
409 void FGAIBallistic::setSlavedLoad(bool l) {
410 _slave_load_to_ac = l;
413 bool FGAIBallistic::getSlavedLoad() const {
414 return _slave_load_to_ac;
417 void FGAIBallistic::setForcePath(const string& p) {
419 if (!_force_path.empty()) {
420 SGPropertyNode *fnode = fgGetNode(_force_path.c_str(), 0, true );
421 _force_node = fnode->getChild("force-lb", 0, true);
422 _force_azimuth_node = fnode->getChild("force-azimuth-deg", 0, true);
423 _force_elevation_node = fnode->getChild("force-elevation-deg", 0, true);
427 bool FGAIBallistic::getHtAGL(){
429 if (globals->get_scenery()->get_elevation_m(SGGeod::fromGeodM(pos, 10000),
430 _elevation_m, &_material)){
431 _ht_agl_ft = pos.getElevationFt() - _elevation_m * SG_METER_TO_FEET;
433 const vector<string>& names = _material->get_names();
435 _solid = _material->get_solid();
436 _load_resistance = _material->get_load_resistance();
437 _frictionFactor =_material->get_friction_factor();
439 props->setStringValue("material/name", names[0].c_str());
441 props->setStringValue("material/name", "");
442 /*cout << "material " << mat_name
443 << " solid " << _solid
444 << " load " << _load_resistance
445 << " frictionFactor " << frictionFactor
455 double FGAIBallistic::getRecip(double az){
456 // calculate the reciprocal of the input azimuth
464 void FGAIBallistic::setPch(double e, double dt, double coeff){
465 double c = dt / (coeff + dt);
466 pitch = (e * c) + (pitch * (1 - c));
469 void FGAIBallistic::setBnk(double r, double dt, double coeff){
470 double c = dt / (coeff + dt);
471 roll = (r * c) + (roll * (1 - c));
474 void FGAIBallistic::setHt(double h, double dt, double coeff){
475 double c = dt / (coeff + dt);
476 _height = (h * c) + (_height * (1 - c));
479 void FGAIBallistic::setHdg(double az, double dt, double coeff){
480 double recip = getRecip(hdg);
481 double c = dt / (coeff + dt);
482 //we need to ensure that we turn the short way to the new hdg
483 if (az < recip && az < hdg && hdg > 180) {
484 hdg = ((az + 360) * c) + (hdg * (1 - c));
485 } else if (az > recip && az > hdg && hdg <= 180){
486 hdg = ((az - 360) * c) + (hdg * (1 - c));
488 hdg = (az * c) + (hdg * (1 - c));
492 double FGAIBallistic::getTgtXOffset() const {
493 return _tgt_x_offset;
496 double FGAIBallistic::getTgtYOffset() const {
497 return _tgt_y_offset;
500 double FGAIBallistic::getTgtZOffset() const {
501 return _tgt_z_offset;
504 void FGAIBallistic::setTgtXOffset(double x){
508 void FGAIBallistic::setTgtYOffset(double y){
512 void FGAIBallistic::setTgtZOffset(double z){
516 void FGAIBallistic::slaveToAC(double dt){
519 pos.setLatitudeDeg(hitchpos.getLatitudeDeg());
520 pos.setLongitudeDeg(hitchpos.getLongitudeDeg());
521 pos.setElevationFt(hitchpos.getElevationFt());
522 setHeading(manager->get_user_heading());
523 setPitch(manager->get_user_pitch() + _pitch_offset);
524 setBank(manager->get_user_roll() + _roll_offset);
525 setSpeed(manager->get_user_speed());
526 //update the mass (slugs)
527 _mass = (_weight_lb + getContents()) / slugs_to_lbs;
529 /*cout <<"_mass "<<_mass <<" " << getContents()
530 <<" " << getContents() / slugs_to_lbs << endl;*/
533 void FGAIBallistic::Run(double dt) {
536 // if life = -1 the object does not die
537 if (_life_timer > life && life != -1)
540 //set the contents in the appropriate tank or other property in the parent to zero
543 //randomise Cd by +- 5%
545 _Cd = _Cd * 0.95 + (0.05 * sg_random());
547 // Adjust Cd by Mach number. The equations are based on curves
548 // for a conventional shell/bullet (no boat-tail).
552 Cdm = 0.0125 * Mach + _Cd;
553 else if (Mach < 1.2 )
554 Cdm = 0.3742 * pow(Mach, 2) - 0.252 * Mach + 0.0021 + _Cd;
556 Cdm = 0.2965 * pow(Mach, -1.1506) + _Cd;
558 //cout << "Mach " << Mach << " Cdm " << Cdm << "// ballistic speed kts "<< speed << endl;
560 // drag = Cd * 0.5 * rho * speed * speed * drag_area;
561 // rho is adjusted for altitude in void FGAIBase::update,
562 // using Standard Atmosphere (sealevel temperature 15C)
563 // acceleration = drag/mass;
564 // adjust speed by drag
565 speed -= (Cdm * 0.5 * rho * speed * speed * _drag_area/_mass) * dt;
567 // don't let speed become negative
571 double speed_fps = speed * SG_KT_TO_FPS;
574 // calculate vertical and horizontal speed components
578 vs = sin( _elevation * SG_DEGREES_TO_RADIANS ) * speed_fps;
579 hs = cos( _elevation * SG_DEGREES_TO_RADIANS ) * speed_fps;
582 //resolve horizontal speed into north and east components:
583 double speed_north_fps = cos(_azimuth / SG_RADIANS_TO_DEGREES) * hs;
584 double speed_east_fps = sin(_azimuth / SG_RADIANS_TO_DEGREES) * hs;
586 // convert horizontal speed (fps) to degrees per second
587 double speed_north_deg_sec = speed_north_fps / ft_per_deg_lat;
588 double speed_east_deg_sec = speed_east_fps / ft_per_deg_lon;
590 // if wind not required, set to zero
592 _wind_from_north = 0;
595 _wind_from_north = manager->get_wind_from_north();
596 _wind_from_east = manager->get_wind_from_east();
599 //calculate velocity due to external force
600 double force_speed_north_deg_sec = 0;
601 double force_speed_east_deg_sec = 0;
602 double vs_force_fps = 0;
603 double hs_force_fps = 0;
604 double v_force_acc_fpss = 0;
605 double force_speed_north_fps = 0;
606 double force_speed_east_fps = 0;
607 double h_force_lbs = 0;
608 double normal_force_lbs = 0;
609 double normal_force_fpss = 0;
610 double static_friction_force_lbs = 0;
611 double dynamic_friction_force_lbs = 0;
612 double friction_force_speed_north_fps = 0;
613 double friction_force_speed_east_fps = 0;
614 double friction_force_speed_north_deg_sec = 0;
615 double friction_force_speed_east_deg_sec = 0;
616 double force_elevation_deg = 0;
618 if (_external_force) {
619 SGPropertyNode *n = fgGetNode(_force_path.c_str(), true);
620 double force_lbs = n->getChild("force-lb", 0, true)->getDoubleValue();
621 force_elevation_deg = n->getChild("force-elevation-deg", 0, true)->getDoubleValue();
622 double force_azimuth_deg = n->getChild("force-azimuth-deg", 0, true)->getDoubleValue();
624 //resolve force into vertical and horizontal components:
625 double v_force_lbs = force_lbs * sin( force_elevation_deg * SG_DEGREES_TO_RADIANS );
626 h_force_lbs = force_lbs * cos( force_elevation_deg * SG_DEGREES_TO_RADIANS );
631 double deadzone = 0.1;
633 if (_ht_agl_ft <= (0 + _ground_offset + deadzone) && _solid){
634 normal_force_lbs = (_mass * slugs_to_lbs) - v_force_lbs;
636 if ( normal_force_lbs < 0 )
637 normal_force_lbs = 0;
639 pos.setElevationFt(0 + _ground_offset);
643 // calculate friction
644 // we assume a static Coefficient of Friction (mu) of 0.62 (wood on concrete)
647 static_friction_force_lbs = mu * normal_force_lbs * _frictionFactor;
649 //adjust horizontal force. We assume that a speed of <= 5 fps is static
650 if (h_force_lbs <= static_friction_force_lbs && hs <= 5){
651 h_force_lbs = hs = 0;
652 speed_north_fps = speed_east_fps = 0;
654 dynamic_friction_force_lbs = (static_friction_force_lbs * 0.95);
656 //ignore wind when on the ground for now
658 _wind_from_north = 0;
665 //acceleration = (force(lbsf)/mass(slugs))
666 v_force_acc_fpss = v_force_lbs/_mass;
667 normal_force_fpss = normal_force_lbs/_mass;
668 double h_force_acc_fpss = h_force_lbs/_mass;
669 double dynamic_friction_acc_fpss = dynamic_friction_force_lbs/_mass;
671 // velocity = acceleration * dt
672 hs_force_fps = h_force_acc_fpss * dt;
673 double friction_force_fps = dynamic_friction_acc_fpss * dt;
675 //resolve horizontal speeds into north and east components:
676 force_speed_north_fps = cos(force_azimuth_deg * SG_DEGREES_TO_RADIANS) * hs_force_fps;
677 force_speed_east_fps = sin(force_azimuth_deg * SG_DEGREES_TO_RADIANS) * hs_force_fps;
679 friction_force_speed_north_fps = cos(getRecip(hdg) * SG_DEGREES_TO_RADIANS) * friction_force_fps;
680 friction_force_speed_east_fps = sin(getRecip(hdg) * SG_DEGREES_TO_RADIANS) * friction_force_fps;
682 // convert horizontal speed (fps) to degrees per second
683 force_speed_north_deg_sec = force_speed_north_fps / ft_per_deg_lat;
684 force_speed_east_deg_sec = force_speed_east_fps / ft_per_deg_lon;
686 friction_force_speed_north_deg_sec = friction_force_speed_north_fps / ft_per_deg_lat;
687 friction_force_speed_east_deg_sec = friction_force_speed_east_fps / ft_per_deg_lon;
690 // convert wind speed (fps) to degrees lat/lon per second
691 double wind_speed_from_north_deg_sec = _wind_from_north / ft_per_deg_lat;
692 double wind_speed_from_east_deg_sec = _wind_from_east / ft_per_deg_lon;
694 //recombine the horizontal velocity components
695 hs = sqrt(((speed_north_fps + force_speed_north_fps + friction_force_speed_north_fps)
696 * (speed_north_fps + force_speed_north_fps + friction_force_speed_north_fps))
697 + ((speed_east_fps + force_speed_east_fps + friction_force_speed_east_fps)
698 * (speed_east_fps + force_speed_east_fps + friction_force_speed_east_fps)));
703 // adjust vertical speed for acceleration of gravity, buoyancy, and vertical force
704 vs -= (_gravity - _buoyancy - v_force_acc_fpss - normal_force_fpss) * dt;
706 if (vs <= 0.00001 && vs >= -0.00001)
710 if(_slave_load_to_ac) {
712 pos.setLatitudeDeg(hitchpos.getLatitudeDeg());
713 pos.setLongitudeDeg(hitchpos.getLongitudeDeg());
714 pos.setElevationFt(hitchpos.getElevationFt());
717 double deadzone = 0.1;
719 if (_ht_agl_ft <= (0 + _ground_offset + deadzone) && _solid){
720 pos.setElevationFt(0 + _ground_offset);
722 pos.setElevationFt(hitchpos.getElevationFt() + _load_offset);
727 pos.setLatitudeDeg( pos.getLatitudeDeg()
728 + (speed_north_deg_sec - wind_speed_from_north_deg_sec
729 + force_speed_north_deg_sec + friction_force_speed_north_deg_sec) * dt );
730 pos.setLongitudeDeg( pos.getLongitudeDeg()
731 + (speed_east_deg_sec - wind_speed_from_east_deg_sec
732 + force_speed_east_deg_sec + friction_force_speed_east_deg_sec) * dt );
733 pos.setElevationFt(pos.getElevationFt() + vs * dt);
736 // recalculate total speed
737 if ( vs == 0 && hs == 0)
740 speed = sqrt( vs * vs + hs * hs) / SG_KT_TO_FPS;
742 // recalculate elevation and azimuth (velocity vectors)
743 _elevation = atan2( vs, hs ) * SG_RADIANS_TO_DEGREES;
744 _azimuth = atan2((speed_east_fps + force_speed_east_fps + friction_force_speed_east_fps),
745 (speed_north_fps + force_speed_north_fps + friction_force_speed_north_fps))
746 * SG_RADIANS_TO_DEGREES;
748 // rationalise azimuth
752 if (_aero_stabilised) { // we simulate rotational moment of inertia by using a filter
753 const double coeff = 0.9;
755 // we assume a symetrical MI about the pitch and yaw axis
756 setPch(_elevation, dt, coeff);
757 setHdg(_azimuth, dt, coeff);
758 } else if (_force_stabilised) { // we simulate rotational moment of inertia by using a filter
759 const double coeff = 0.9;
760 double ratio = h_force_lbs/(_mass * slugs_to_lbs);
762 if (ratio > 1) ratio = 1;
763 if (ratio < -1) ratio = -1;
765 double force_pitch = acos(ratio) * SG_RADIANS_TO_DEGREES;
767 if (force_pitch <= force_elevation_deg)
768 force_pitch = force_elevation_deg;
770 // we assume a symetrical MI about the pitch and yaw axis
771 setPch(force_pitch,dt, coeff);
772 setHdg(_azimuth, dt, coeff);
775 //do impacts and collisions
776 if (_report_impact && !_impact_reported)
779 if (_report_collision && !_collision_reported)
782 // set destruction flag if altitude less than sea level -1000
783 if (altitude_ft < -1000.0 && life != -1)
788 double FGAIBallistic::_getTime() const {
792 void FGAIBallistic::handle_impact() {
794 // try terrain intersection
798 if (_ht_agl_ft <= 0) {
799 SG_LOG(SG_GENERAL, SG_DEBUG, "AIBallistic: terrain impact");
800 report_impact(_elevation_m);
801 _impact_reported = true;
805 } else if (_subID == 0) // kill the AIObject if there is no subsubmodel
810 void FGAIBallistic::handle_collision()
812 const FGAIBase *object = manager->calcCollision(pos.getElevationFt(),
813 pos.getLatitudeDeg(),pos.getLongitudeDeg(), _fuse_range);
816 SG_LOG(SG_GENERAL, SG_DEBUG, "AIBallistic: object hit");
817 report_impact(pos.getElevationM(), object);
818 _collision_reported = true;
822 void FGAIBallistic::report_impact(double elevation, const FGAIBase *object)
824 _impact_lat = pos.getLatitudeDeg();
825 _impact_lon = pos.getLongitudeDeg();
826 _impact_elev = elevation;
827 _impact_speed = speed * SG_KT_TO_MPS;
829 _impact_pitch = pitch;
832 SGPropertyNode *n = props->getNode("impact", true);
834 n->setStringValue("type", object->getTypeString());
836 n->setStringValue("type", "terrain");
838 n->setDoubleValue("longitude-deg", _impact_lon);
839 n->setDoubleValue("latitude-deg", _impact_lat);
840 n->setDoubleValue("elevation-m", _impact_elev);
841 n->setDoubleValue("heading-deg", _impact_hdg);
842 n->setDoubleValue("pitch-deg", _impact_pitch);
843 n->setDoubleValue("roll-deg", _impact_roll);
844 n->setDoubleValue("speed-mps", _impact_speed);
846 _impact_report_node->setStringValue(props->getPath());
849 SGVec3d FGAIBallistic::getCartUserPos() const {
850 SGVec3d cartUserPos = SGVec3d::fromGeod(userpos);
854 SGVec3d FGAIBallistic::getCartHitchPos() const{
856 // convert geodetic positions to geocentered
857 SGVec3d cartuserPos = getCartUserPos();
858 SGVec3d cartPos = getCartPos();
860 // Transform to the right coordinate frame, configuration is done in
861 // the x-forward, y-right, z-up coordinates (feet), computation
862 // in the simulation usual body x-forward, y-right, z-down coordinates
864 SGVec3d _off(_x_offset * SG_FEET_TO_METER,
865 _y_offset * SG_FEET_TO_METER,
866 -_z_offset * SG_FEET_TO_METER);
868 // Transform the user position to the horizontal local coordinate system.
869 SGQuatd hlTrans = SGQuatd::fromLonLat(userpos);
871 // and postrotate the orientation of the user model wrt the horizontal
873 hlTrans *= SGQuatd::fromYawPitchRollDeg(
874 manager->get_user_heading(),
875 manager->get_user_pitch(),
876 manager->get_user_roll());
878 // The offset converted to the usual body fixed coordinate system
879 // rotated to the earth-fixed coordinates axis
880 SGVec3d off = hlTrans.backTransform(_off);
882 // Add the position offset of the user model to get the geocentered position
883 SGVec3d offsetPos = cartuserPos + off;
888 void FGAIBallistic::setHitchPos(){
889 // convert the hitch geocentered position to geodetic
890 SGVec3d carthitchPos = getCartHitchPos();
892 SGGeodesy::SGCartToGeod(carthitchPos, hitchpos);
895 double FGAIBallistic::getDistanceLoadToHitch() const {
896 //calculate the distance load to hitch
897 SGVec3d carthitchPos = getCartHitchPos();
898 SGVec3d cartPos = getCartPos();
900 SGVec3d diff = carthitchPos - cartPos;
901 double distance = norm(diff);
902 return distance * SG_METER_TO_FEET;
905 void FGAIBallistic::setHitchVelocity(double dt) {
906 //calculate the distance from the previous hitch position
907 SGVec3d carthitchPos = getCartHitchPos();
908 SGVec3d diff = carthitchPos - _oldcarthitchPos;
910 double distance = norm(diff);
912 //calculate speed knots
913 speed = (distance/dt) * SG_MPS_TO_KT;
915 //now calulate the angle between the old and current hitch positions (degrees)
917 double daltM = hitchpos.getElevationM() - oldhitchpos.getElevationM();
919 if (fabs(distance) < SGLimits<float>::min()) {
922 double sAngle = daltM/distance;
923 sAngle = SGMiscd::min(1, SGMiscd::max(-1, sAngle));
924 angle = SGMiscd::rad2deg(asin(sAngle));
929 //calculate the bearing of the new hitch position from the old
930 double az1, az2, dist;
932 geo_inverse_wgs_84(oldhitchpos, hitchpos, &az1, &az2, &dist);
936 // and finally store the new values
937 _oldcarthitchPos = carthitchPos;
938 oldhitchpos = hitchpos;
941 double FGAIBallistic::getElevLoadToHitch() const {
942 // now the angle, positive angles are upwards
943 double distance = getDistanceLoadToHitch() * SG_FEET_TO_METER;
945 double daltM = hitchpos.getElevationM() - pos.getElevationM();
947 if (fabs(distance) < SGLimits<float>::min()) {
950 double sAngle = daltM/distance;
951 sAngle = SGMiscd::min(1, SGMiscd::max(-1, sAngle));
952 angle = SGMiscd::rad2deg(asin(sAngle));
958 double FGAIBallistic::getBearingLoadToHitch() const {
959 //calculate the bearing and range of the second pos from the first
960 double az1, az2, distance;
962 geo_inverse_wgs_84(pos, hitchpos, &az1, &az2, &distance);
967 double FGAIBallistic::getRelBrgHitchToUser() const {
968 //calculate the relative bearing
969 double az1, az2, distance;
971 geo_inverse_wgs_84(hitchpos, userpos, &az1, &az2, &distance);
973 double rel_brg = az1 - hdg;
981 double FGAIBallistic::getElevHitchToUser() const {
983 //calculate the distance from the user position
984 SGVec3d carthitchPos = getCartHitchPos();
985 SGVec3d cartuserPos = getCartUserPos();
987 SGVec3d diff = cartuserPos - carthitchPos;
989 double distance = norm(diff);
992 double daltM = userpos.getElevationM() - hitchpos.getElevationM();
994 // now the angle, positive angles are upwards
995 if (fabs(distance) < SGLimits<float>::min()) {
998 double sAngle = daltM/distance;
999 sAngle = SGMiscd::min(1, SGMiscd::max(-1, sAngle));
1000 angle = SGMiscd::rad2deg(asin(sAngle));
1006 void FGAIBallistic::setTgtOffsets(double dt, double coeff){
1007 double c = dt / (coeff + dt);
1009 _x_offset = (_tgt_x_offset * c) + (_x_offset * (1 - c));
1010 _y_offset = (_tgt_y_offset * c) + (_y_offset * (1 - c));
1011 _z_offset = (_tgt_z_offset * c) + (_z_offset * (1 - c));
1014 void FGAIBallistic::formateToAC(double dt){
1016 setTgtOffsets(dt, 25);
1018 setHitchVelocity(dt);
1020 // elapsed time has a random initialisation so that each
1021 // wingman moves differently
1022 _elapsed_time += dt;
1024 // we derive a sine based factor to give us smoothly
1025 // varying error between -1 and 1
1026 double factor = sin(SGMiscd::deg2rad(_elapsed_time * 10));
1027 double r_angle = 5 * factor;
1028 double p_angle = 2.5 * factor;
1029 double h_angle = 5 * factor;
1030 double h_feet = 3 * factor;
1032 pos.setLatitudeDeg(hitchpos.getLatitudeDeg());
1033 pos.setLongitudeDeg(hitchpos.getLongitudeDeg());
1037 if(_ht_agl_ft <= 10) {
1038 _height = userpos.getElevationFt();
1039 } else if (_ht_agl_ft > 10 && _ht_agl_ft <= 150 ) {
1040 setHt(userpos.getElevationFt(), dt, 1.0);
1041 } else if (_ht_agl_ft > 150 && _ht_agl_ft <= 250) {
1042 setHt(hitchpos.getElevationFt()+ h_feet, dt, 0.75);
1044 setHt(hitchpos.getElevationFt()+ h_feet, dt, 0.5);
1046 pos.setElevationFt(_height);
1049 // these calculations are unreliable at slow speeds
1051 setHdg(_azimuth + h_angle, dt, 0.9);
1052 setPch(_elevation + p_angle + _pitch_offset, dt, 0.9);
1054 if (roll <= 115 && roll >= -115)
1055 setBnk(manager->get_user_roll() + r_angle + _roll_offset, dt, 0.5);
1057 roll = manager->get_user_roll() + r_angle + _roll_offset;
1060 setHdg(manager->get_user_heading(), dt, 0.9);
1061 setPch(manager->get_user_pitch() + _pitch_offset, dt, 0.9);
1062 setBnk(manager->get_user_roll() + _roll_offset, dt, 0.9);