2 #include "BodyEnvironment.hpp"
3 #include "RigidBody.hpp"
14 Hitch::Hitch(const char *name)
16 if (fgGetNode("/sim/hitches", true))
17 _node = fgGetNode("/sim/hitches", true)->getNode(name, true);
21 _pos[i] = _force[i] = _winchPos[i] = _mp_lpos[i]=_towEndForce[i]=_mp_force[i]=0;
23 _global_ground[i] = 0;
24 _global_ground[2] = 1;
25 _global_ground[3] = -1e5;
30 _towElasticConstant=1e5;
31 _towBrakeForce=100000;
35 _winchInitialTowLength=1000;
39 _winchMaxTowLength=1000;
42 _towEndIsConnectedToProperty=false;
44 _nodeIsMultiplayer=false;
45 _nodeIsAiAircraft=false;
46 _forceIsCalculatedByMaster=false;
49 _height_above_ground=0;
50 _winch_height_above_ground=0;
54 _displayed_len_lower_dist_message=false;
57 _mpAutoConnectPeriod=0;
58 _timeToNextAutoConnectTry=0;
59 _timeToNextReConnectTry=10;
60 _speed_in_tow_direction=0;
62 _mp_last_reported_dist=0;
63 _mp_last_reported_v=0;
65 _mp_open_last_state=false;
66 _timeLagCorrectedDist=0;
70 #define TIE(x,v) _tiedProperties.Tie(_node->getNode(x, true),v)
71 TIE("tow/length", SGRawValuePointer<float>(&_towLength));
72 TIE("tow/elastic-constant",SGRawValuePointer<float>(&_towElasticConstant));
73 TIE("tow/weight-per-m-kg-m",SGRawValuePointer<float>(&_towWeightPerM));
74 TIE("tow/brake-force",SGRawValuePointer<float>(&_towBrakeForce));
75 TIE("winch/max-speed-m-s",SGRawValuePointer<float>(&_winchMaxSpeed));
76 TIE("winch/rel-speed",SGRawValuePointer<float>(&_winchRelSpeed));
77 TIE("winch/initial-tow-length-m",SGRawValuePointer<float>(&_winchInitialTowLength));
78 TIE("winch/min-tow-length-m",SGRawValuePointer<float>(&_winchMinTowLength));
79 TIE("winch/max-tow-length-m",SGRawValuePointer<float>(&_winchMaxTowLength));
80 TIE("winch/global-pos-x",SGRawValuePointer<double>(&_winchPos[0]));
81 TIE("winch/global-pos-y",SGRawValuePointer<double>(&_winchPos[1]));
82 TIE("winch/global-pos-z",SGRawValuePointer<double>(&_winchPos[2]));
83 TIE("winch/max-power",SGRawValuePointer<float>(&_winchPower));
84 TIE("winch/max-force",SGRawValuePointer<float>(&_winchMaxForce));
85 TIE("winch/actual-force",SGRawValuePointer<float>(&_winchActualForce));
86 TIE("tow/end-force-x",SGRawValuePointer<float>(&_reportTowEndForce[0]));
87 TIE("tow/end-force-y",SGRawValuePointer<float>(&_reportTowEndForce[1]));
88 TIE("tow/end-force-z",SGRawValuePointer<float>(&_reportTowEndForce[2]));
89 TIE("force",SGRawValuePointer<float>(&_forceMagnitude));
90 TIE("open",SGRawValuePointer<bool>(&_open));
91 TIE("force-is-calculated-by-other",SGRawValuePointer<bool>(&_forceIsCalculatedByMaster));
92 TIE("local-pos-x",SGRawValuePointer<float>(&_pos[0]));
93 TIE("local-pos-y",SGRawValuePointer<float>(&_pos[1]));
94 TIE("local-pos-z",SGRawValuePointer<float>(&_pos[2]));
95 TIE("tow/dist",SGRawValuePointer<float>(&_dist));
96 TIE("tow/dist-time-lag-corrected",SGRawValuePointer<float>(&_timeLagCorrectedDist));
97 TIE("tow/connected-to-property-node",SGRawValuePointer<bool>(&_towEndIsConnectedToProperty));
98 TIE("tow/connected-to-mp-node",SGRawValuePointer<bool>(&_nodeIsMultiplayer));
99 TIE("tow/connected-to-ai-node",SGRawValuePointer<bool>(&_nodeIsAiAircraft));
100 TIE("tow/connected-to-ai-or-mp-id",SGRawValuePointer<int>(&_nodeID));
101 TIE("debug/hitch-height-above-ground",SGRawValuePointer<float>(&_height_above_ground));
102 TIE("debug/tow-end-height-above-ground",SGRawValuePointer<float>(&_winch_height_above_ground));
103 TIE("debug/tow-rel-lo-pos",SGRawValuePointer<float>(&_loPosFrac));
104 TIE("debug/tow-lowest-pos-height",SGRawValuePointer<float>(&_lowest_tow_height));
105 TIE("is-slave",SGRawValuePointer<bool>(&_isSlave));
106 TIE("speed-in-tow-direction",SGRawValuePointer<float>(&_speed_in_tow_direction));
107 TIE("mp-auto-connect-period",SGRawValuePointer<float>(&_mpAutoConnectPeriod));
108 TIE("mp-time-lag",SGRawValuePointer<float>(&_mp_time_lag));
110 _node->setStringValue("tow/node","");
111 _node->setStringValue("tow/connected-to-ai-or-mp-callsign");
112 _node->setBoolValue("broken",false);
118 _tiedProperties.Untie();
122 void Hitch::setPosition(float* position)
125 for(i=0; i<3; i++) _pos[i] = position[i];
128 void Hitch::setTowLength(float length)
133 void Hitch::setOpen(bool isOpen)
135 //test if we already processed this before
136 //without this test a binded property could
137 //try to close the Hitch every run
138 //it will close, if we are near the end
139 //e.g. if we are flying over the parked
141 if (isOpen==_last_wish)
147 void Hitch::setTowElasticConstant(float sc)
149 _towElasticConstant=sc;
152 void Hitch::setTowBreakForce(float bf)
157 void Hitch::setWinchMaxForce(float f)
162 void Hitch::setTowWeightPerM(float rw)
167 void Hitch::setWinchMaxSpeed(float mws)
172 void Hitch::setWinchRelSpeed(float rws)
177 void Hitch::setWinchPosition(double *winchPosition)//in global coordinates!
179 for (int i=0; i<3;i++)
180 _winchPos[i]=winchPosition[i];
183 void Hitch::setMpAutoConnectPeriod(float dt)
185 _mpAutoConnectPeriod=dt;
188 void Hitch::setForceIsCalculatedByOther(bool b)
190 _forceIsCalculatedByMaster=b;
193 std::string Hitch::getConnectedPropertyNode() const
196 return _towEndNode->getDisplayName();
198 return std::string("");
201 void Hitch::setConnectedPropertyNode(const char *nodename)
203 _towEndNode=fgGetNode(nodename,false);
206 void Hitch::setWinchPositionAuto(bool doit)
208 static bool lastState=false;
220 // The ground plane transformed to the local frame.
222 _state->planeGlobalToLocal(_global_ground, ground);
225 //find a normalized vector pointing forward parallel to the ground
229 Math::cross3(ground,help,help);
230 //multiplay by initial tow length;
231 //reduced by 1m to be able to close the
232 //hitch either if the glider slips backwards a bit
233 Math::mul3((_winchInitialTowLength-1.),help,help);
234 //add to the actual pos
235 Math::add3(_pos,help,lWinchPos);
236 //put it onto the ground plane
237 Math::mul3(ground[3],ground,help);
238 Math::add3(lWinchPos,help,lWinchPos);
240 _state->posLocalToGlobal(lWinchPos,_winchPos);
241 _towLength=_winchInitialTowLength;
242 fgSetString("/sim/messages/pilot", "Connected to winch!");
245 _node->setBoolValue("broken",false);
247 //set the dist value (if not, the hitch would open in the next calcforce run
249 Math::sub3(lWinchPos,_pos,delta);
250 _dist=Math::mag3(delta);
253 void Hitch::findBestAIObject(bool doit,bool running_as_autoconnect)
255 static bool lastState=false;
258 if (!running_as_autoconnect)
260 //if this function is binded to an input, it will be called every frame as long as the key is pressed.
261 //therefore wait for a key-release before running it again.
272 _state->posLocalToGlobal(_pos,gpos);
273 double bestdist=_towLength*_towLength;//squared!
274 _towEndIsConnectedToProperty=false;
275 SGPropertyNode * ainode = fgGetNode("/ai/models",false);
277 char myCallsign[256]="***********";
278 if (running_as_autoconnect)
281 SGPropertyNode *cs=fgGetNode("/sim/multiplay/callsign",false);
284 strncpy(myCallsign,cs->getStringValue(),256);
287 //reset tow length for search radius. Lentgh will be later copied from master
288 _towLength=_winchInitialTowLength;
291 vector <SGPropertyNode_ptr> nodes;//<SGPropertyNode_ptr>
292 for (int i=0;i<ainode->nChildren();i++)
294 SGPropertyNode * n=ainode->getChild(i);
295 _nodeIsMultiplayer = strncmp("multiplayer",n->getName(),11)==0;
296 _nodeIsAiAircraft = strncmp("aircraft",n->getName(),8)==0;
297 if (!(_nodeIsMultiplayer || _nodeIsAiAircraft))
299 if (running_as_autoconnect)
301 if (!_nodeIsMultiplayer)
303 if(n->getBoolValue("sim/hitches/aerotow/open",true)) continue;
304 if(strncmp(myCallsign,n->getStringValue("sim/hitches/aerotow/tow/connected-to-ai-or-mp-callsign"),255)!=0)
308 pos[0]=n->getDoubleValue("position/global-x",0);
309 pos[1]=n->getDoubleValue("position/global-y",0);
310 pos[2]=n->getDoubleValue("position/global-z",0);
312 for (int j=0;j<3;j++)
313 dist+=(pos[j]-gpos[j])*(pos[j]-gpos[j]);
318 _towEndIsConnectedToProperty=true;
319 //_node->setStringValue("tow/node",n->getPath());
320 _node->setStringValue("tow/node",n->getDisplayName());
321 _nodeID=n->getIntValue("id",0);
322 _node->setStringValue("tow/connected-to-ai-or-mp-callsign",n->getStringValue("callsign"));
329 if (!running_as_autoconnect)
331 std::stringstream message;
332 message<<_node->getStringValue("tow/connected-to-ai-or-mp-callsign")
333 <<", I am on your hook, distance "<<Math::sqrt(bestdist)<<" meter.";
334 fgSetString("/sim/messages/pilot", message.str().c_str());
338 std::stringstream message;
339 message<<_node->getStringValue("tow/connected-to-ai-or-mp-callsign")
340 <<": I am on your hook, distance "<<Math::sqrt(bestdist)<<" meter.";
341 fgSetString("/sim/messages/ai-plane", message.str().c_str());
343 if (running_as_autoconnect)
345 //set the dist value to some value below the tow lentgh (if not, the hitch
346 //would open in the next calc force run
347 _dist=_towLength*0.5;
348 _mp_open_last_state=true;
351 if (!running_as_autoconnect)
353 fgSetString("/sim/messages/atc", "Sorry, no aircraft for aerotow!");
357 void Hitch::setWinchInitialTowLength(float length)
359 _winchInitialTowLength=length;
362 void Hitch::setWinchPower(float power)
367 void Hitch::setWinchMaxTowLength(float length)
369 _winchMaxTowLength=length;
372 void Hitch::setWinchMinTowLength(float length)
374 _winchMinTowLength=length;
377 void Hitch::setGlobalGround(double *global_ground, float *global_vel)
380 for(i=0; i<4; i++) _global_ground[i] = global_ground[i];
381 for(i=0; i<3; i++) _global_vel[i] = global_vel[i];
384 void Hitch::getPosition(float* out)
387 for(i=0; i<3; i++) out[i] = _pos[i];
390 float Hitch::getTowLength(void)
395 void Hitch::calcForce(Ground *g_cb, RigidBody* body, State* s)
397 float lWinchPos[3],delta[3],deltaN[3];
399 s->posGlobalToLocal(_winchPos,lWinchPos);
400 Math::sub3(lWinchPos,_pos,delta);
401 if(!_towEndIsConnectedToProperty)
402 _dist=Math::mag3(delta);
404 _dist=Math::mag3(lWinchPos); //use the aircraft center as reference for distance calculation
405 //this position is transferred to the MP-Aircraft.
406 //With this trick, both player in aerotow get the same length
407 Math::unit3(delta,deltaN);
409 s->velGlobalToLocal(s->v,lvel);
410 _speed_in_tow_direction=Math::dot3(lvel,deltaN);
411 if (_towEndIsConnectedToProperty && _nodeIsMultiplayer)
413 float mp_delta_dist_due_to_time_lag=0.5*_mp_time_lag*(-_mp_v+_speed_in_tow_direction);
414 _timeLagCorrectedDist=_dist+mp_delta_dist_due_to_time_lag;
415 if(_forceIsCalculatedByMaster && !_open)
417 s->velGlobalToLocal(_mp_force,_force);
422 _timeLagCorrectedDist=_dist;
425 _force[0]=_force[1]=_force[2]=0;
430 _forceMagnitude=(_dist-_towLength)/_towLength*_towElasticConstant;
432 _forceMagnitude=2*_towBrakeForce;
435 if(_forceMagnitude>=_towBrakeForce)
439 _node->setBoolValue("broken",true);
440 _force[0]=_force[1]=_force[2]=0;
441 _towEndForce[0]=_towEndForce[1]=_towEndForce[2]=0;
442 _reportTowEndForce[0]=_reportTowEndForce[1]=_reportTowEndForce[2]=0;
445 Math::mul3(_forceMagnitude,deltaN,_force);
446 Math::mul3(-1.,_force,_towEndForce);
447 _winchActualForce=_forceMagnitude; //missing: gravity on this end and friction
448 //Add the gravitiy of the rope.
449 //calculate some numbers:
450 float grav_force=_towWeightPerM*_towLength*9.81;
451 //the length of the gravity-expanded row:
452 float leng=_towLength+grav_force*_towLength/_towElasticConstant;
453 // The ground plane transformed to the local frame.
455 s->planeGlobalToLocal(_global_ground, ground);
457 // The velocity of the contact patch transformed to local coordinates.
459 //s->velGlobalToLocal(_global_vel, glvel);
461 _height_above_ground = ground[3] - Math::dot3(_pos, ground);
463 //the same for the winch-pos (the pos of the tow end)
464 _winch_height_above_ground = ground[3] - Math::dot3(lWinchPos, ground);
466 //the frac of the grav force acting on _pos:
467 float grav_frac=0.5*(1+(_height_above_ground-_winch_height_above_ground)/leng);
468 grav_frac=Math::clamp(grav_frac,0,1);
469 float grav_frac_tow_end=1-grav_frac;
470 //reduce grav_frac, if the tow has ground contact.
471 if (_height_above_ground<leng) //if not, the tow can not be on ground
473 float fa[3],fb[3],fg[3];
474 //the grav force an the hitch position:
475 Math::mul3(-grav_frac*grav_force,ground,fg);
476 //the total force on hitch postion:
477 Math::add3(fg,_force,fa);
478 //the grav force an the tow end position:
479 Math::mul3(-(1-grav_frac)*grav_force,ground,fg);
480 //the total force on tow end postion:
481 //note: sub: _force on tow-end is negative of force on hitch postion
482 Math::sub3(fg,_force,fb);
483 float fa_=Math::mag3(fa);
484 float fb_=Math::mag3(fb);
485 float stretchedTowLen;
486 stretchedTowLen=_towLength*(1.+(fa_+fb_)/(2*_towElasticConstant));
487 //the relative position of the lowest postion of the tow:
489 _loPosFrac=fa_/(fa_+fb_);
492 //dist to tow-end parallel to ground
495 //Math::cross3(delta,ground,help);//as long as we calculate the dist without _pos, od it with lWinchpos, the dist to our center....
496 Math::cross3(lWinchPos,ground,help);
497 ground_dist=Math::mag3(help);
498 //height of lowest tow pos (relative to _pos)
499 _lowest_tow_height=_loPosFrac*Math::sqrt(Math::abs(stretchedTowLen*stretchedTowLen-ground_dist*ground_dist));
500 if (_height_above_ground<_lowest_tow_height)
502 if (_height_above_ground>1e-3)
503 grav_frac*=_height_above_ground/_lowest_tow_height;
507 if (_winch_height_above_ground<(_lowest_tow_height-_height_above_ground+_winch_height_above_ground))
509 if (_winch_height_above_ground>1e-3)
510 grav_frac_tow_end*=_winch_height_above_ground/
511 (_lowest_tow_height-_height_above_ground+_winch_height_above_ground);
516 else _lowest_tow_height=_loPosFrac=-1; //for debug output
517 float grav_force_v[3];
518 Math::mul3(grav_frac*grav_force,ground,grav_force_v);
519 Math::add3(grav_force_v,_force,_force);
520 _forceMagnitude=Math::mag3(_force);
521 //the same for the tow end:
522 Math::mul3(grav_frac_tow_end*grav_force,ground,grav_force_v);
523 Math::add3(grav_force_v,_towEndForce,_towEndForce);
524 s->velLocalToGlobal(_towEndForce,_towEndForce);
526 if(_forceMagnitude>=_towBrakeForce)
530 _node->setBoolValue("broken",true);
531 _force[0]=_force[1]=_force[2]=0;
532 _towEndForce[0]=_towEndForce[1]=_towEndForce[2]=0;
538 // Computed values: total force
539 void Hitch::getForce(float* force, float* off)
541 Math::set3(_force, force);
542 Math::set3(_pos, off);
545 void Hitch::integrate (float dt)
547 //check if hitch has opened or closed, if yes: message
548 if (_open !=_oldOpen)
552 if (_dist>_towLength*1.00001)
554 std::stringstream message;
555 message<<"Could not lock hitch (tow length is insufficient) on hitch "
556 <<_node->getName()<<" "<<_node->getIndex()<<"!";
557 fgSetString("/sim/messages/pilot", message.str().c_str());
561 _node->setBoolValue("broken",false);
563 std::stringstream message;
564 if (_node->getBoolValue("broken",false)&&_open)
565 message<<"Oh no, the tow is broken";
567 message<<(_open?"Opened hitch ":"Locked hitch ")<<_node->getName()<<" "<<_node->getIndex()<<"!";
568 fgSetString("/sim/messages/pilot", message.str().c_str());
572 //check, if tow end should be searched in all MP-aircrafts
573 if(_open && _mpAutoConnectPeriod)
576 _timeToNextAutoConnectTry-=dt;
577 if ((_timeToNextAutoConnectTry>_mpAutoConnectPeriod) || (_timeToNextAutoConnectTry<0))
579 _timeToNextAutoConnectTry=_mpAutoConnectPeriod;
580 //search for MP-Aircraft, which is towed with us
581 findBestAIObject(true,true);
584 //check, if tow end can be modified by property, if yes: update
585 if(_towEndIsConnectedToProperty)
589 //_towEndNode=fgGetNode(_node->getStringValue("tow/node"), false);
591 strncpy(towNode,_node->getStringValue("tow/node"),256);
593 _towEndNode=fgGetNode("ai/models")->getNode(towNode, false);
594 //AI and multiplayer objects seem to change node?
595 //Check if we have the right one by callsign
596 if (_nodeIsMultiplayer || _nodeIsAiAircraft)
598 char MPcallsign[256]="";
600 MPc=_node->getStringValue("tow/connected-to-ai-or-mp-callsign");
603 strncpy(MPcallsign,MPc,256);
606 if (((_towEndNode)&&(strncmp(_towEndNode->getStringValue("callsign"),MPcallsign,255)!=0))||!_towEndNode)
608 _timeToNextReConnectTry-=dt;
609 if((_timeToNextReConnectTry<0)||(_timeToNextReConnectTry>10))
611 _timeToNextReConnectTry=10;
612 SGPropertyNode * ainode = fgGetNode("/ai/models",false);
615 for (int i=0;i<ainode->nChildren();i++)
617 SGPropertyNode * n=ainode->getChild(i);
618 if(_nodeIsMultiplayer?strncmp("multiplayer",n->getName(),11)==0:strncmp("aircraft",n->getName(),8))
619 if (strcmp(n->getStringValue("callsign"),MPcallsign)==0)//found
622 //_node->setStringValue("tow/node",n->getPath());
623 _node->setStringValue("tow/node",n->getDisplayName());
632 _winchPos[0]=_towEndNode->getDoubleValue("position/global-x",_winchPos[0]);
633 _winchPos[1]=_towEndNode->getDoubleValue("position/global-y",_winchPos[1]);
634 _winchPos[2]=_towEndNode->getDoubleValue("position/global-z",_winchPos[2]);
635 _mp_lpos[0]=_towEndNode->getFloatValue("sim/hitches/aerotow/local-pos-x",0);
636 _mp_lpos[1]=_towEndNode->getFloatValue("sim/hitches/aerotow/local-pos-y",0);
637 _mp_lpos[2]=_towEndNode->getFloatValue("sim/hitches/aerotow/local-pos-z",0);
638 _mp_dist=_towEndNode->getFloatValue("sim/hitches/aerotow/tow/dist");
639 _mp_v=_towEndNode->getFloatValue("sim/hitches/aerotow/speed-in-tow-direction");
640 _mp_force[0]=_towEndNode->getFloatValue("sim/hitches/aerotow/tow/end-force-x",0);
641 _mp_force[1]=_towEndNode->getFloatValue("sim/hitches/aerotow/tow/end-force-y",0);
642 _mp_force[2]=_towEndNode->getFloatValue("sim/hitches/aerotow/tow/end-force-z",0);
646 #define gf(a,b) a=_towEndNode->getFloatValue(b,a)
647 #define gb(a,b) a=_towEndNode->getBoolValue(b,a)
648 gf(_towLength,"sim/hitches/aerotow/tow/length");
649 gf(_towElasticConstant,"sim/hitches/aerotow/tow/elastic-constant");
650 gf(_towWeightPerM,"sim/hitches/aerotow/tow/weight-per-m-kg-m");
651 gf(_towBrakeForce,"sim/hitches/aerotow/brake-force");
652 gb(_open,"sim/hitches/aerotow/open");
653 gb(_mp_is_slave,"sim/hitches/aerotow/is-slave");
656 if (_mp_is_slave) _isSlave=false; //someone should be master
660 //check if other has opened hitch, but is neccessary, that it was closed before
661 bool mp_open=_towEndNode->getBoolValue("sim/hitches/aerotow/open",_mp_open_last_state);
662 if (mp_open != _mp_open_last_state) //state has changed
664 _mp_open_last_state=mp_open; //store that value
670 std::stringstream message;
671 message<<_node->getStringValue("tow/connected-to-ai-or-mp-callsign")
672 <<": I have released the tow!";
673 fgSetString("/sim/messages/ai-plane", message.str().c_str());
678 //try to calculate the time lag
679 if ((_mp_last_reported_dist!=_mp_dist)||(_mp_last_reported_v!=_mp_v)) //new data;
681 _mp_last_reported_dist=_mp_dist;
682 _mp_last_reported_v=_mp_v;
683 float total_v=-_mp_v+_speed_in_tow_direction;//mp has opposite tow direction
684 float abs_v=Math::abs(total_v);
687 float actual_time_lag_guess=(_mp_dist-_dist)/total_v;
688 //check, if it sounds ok
689 if((actual_time_lag_guess>0)&&(actual_time_lag_guess<5))
691 float frac=abs_v*0.01;
692 if (frac>0.05) frac=0.05;
693 // if we are slow, the guess of the lag can be rather wrong. as faster we are
694 // the better the guess. Therefore frac is proportiona to the speed. Clamp it
696 _mp_time_lag=(1-frac)*_mp_time_lag+frac*actual_time_lag_guess;
703 //set the _reported_tow_end_force
704 Math::set3(_towEndForce,_reportTowEndForce);
707 if (_winchRelSpeed==0) return;
708 float factor=1,offset=0;
709 if (_winchActualForce>_winchMaxForce)
710 offset=-(_winchActualForce-_winchMaxForce)/_winchMaxForce*20;
711 if (_winchRelSpeed>0.01) // to avoit div by zero
713 float maxForcePowerLimit=_winchPower/(_winchRelSpeed*_winchMaxSpeed);
714 if (_winchActualForce>maxForcePowerLimit)
715 factor-=(_winchActualForce-maxForcePowerLimit)/maxForcePowerLimit;
717 _towLength-=dt*(factor*_winchRelSpeed+offset)*_winchMaxSpeed;
718 if (_towLength<=_winchMinTowLength)
720 if (_winchRelSpeed<0)
722 _towLength=_winchMinTowLength;
725 if (_towLength>=_winchMaxTowLength)
727 if (_winchRelSpeed<0)
729 _towLength=_winchMaxTowLength;
737 }; // namespace yasim