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;
69 _node->tie("tow/length",SGRawValuePointer<float>(&_towLength));
70 _node->tie("tow/elastic-constant",SGRawValuePointer<float>(&_towElasticConstant));
71 _node->tie("tow/weight-per-m-kg-m",SGRawValuePointer<float>(&_towWeightPerM));
72 _node->tie("tow/brake-force",SGRawValuePointer<float>(&_towBrakeForce));
73 _node->tie("winch/max-speed-m-s",SGRawValuePointer<float>(&_winchMaxSpeed));
74 _node->tie("winch/rel-speed",SGRawValuePointer<float>(&_winchRelSpeed));
75 _node->tie("winch/initial-tow-length-m",SGRawValuePointer<float>(&_winchInitialTowLength));
76 _node->tie("winch/min-tow-length-m",SGRawValuePointer<float>(&_winchMinTowLength));
77 _node->tie("winch/max-tow-length-m",SGRawValuePointer<float>(&_winchMaxTowLength));
78 _node->tie("winch/global-pos-x",SGRawValuePointer<double>(&_winchPos[0]));
79 _node->tie("winch/global-pos-y",SGRawValuePointer<double>(&_winchPos[1]));
80 _node->tie("winch/global-pos-z",SGRawValuePointer<double>(&_winchPos[2]));
81 _node->tie("winch/max-power",SGRawValuePointer<float>(&_winchPower));
82 _node->tie("winch/max-force",SGRawValuePointer<float>(&_winchMaxForce));
83 _node->tie("winch/actual-force",SGRawValuePointer<float>(&_winchActualForce));
84 _node->tie("tow/end-force-x",SGRawValuePointer<float>(&_reportTowEndForce[0]));
85 _node->tie("tow/end-force-y",SGRawValuePointer<float>(&_reportTowEndForce[1]));
86 _node->tie("tow/end-force-z",SGRawValuePointer<float>(&_reportTowEndForce[2]));
87 _node->tie("force",SGRawValuePointer<float>(&_forceMagnitude));
88 _node->tie("open",SGRawValuePointer<bool>(&_open));
89 _node->tie("force-is-calculated-by-other",SGRawValuePointer<bool>(&_forceIsCalculatedByMaster));
90 _node->tie("local-pos-x",SGRawValuePointer<float>(&_pos[0]));
91 _node->tie("local-pos-y",SGRawValuePointer<float>(&_pos[1]));
92 _node->tie("local-pos-z",SGRawValuePointer<float>(&_pos[2]));
93 _node->tie("tow/dist",SGRawValuePointer<float>(&_dist));
94 _node->tie("tow/dist-time-lag-corrected",SGRawValuePointer<float>(&_timeLagCorrectedDist));
95 _node->tie("tow/connected-to-property-node",SGRawValuePointer<bool>(&_towEndIsConnectedToProperty));
96 _node->tie("tow/connected-to-mp-node",SGRawValuePointer<bool>(&_nodeIsMultiplayer));
97 _node->tie("tow/connected-to-ai-node",SGRawValuePointer<bool>(&_nodeIsAiAircraft));
98 _node->tie("tow/connected-to-ai-or-mp-id",SGRawValuePointer<int>(&_nodeID));
99 _node->tie("debug/hitch-height-above-ground",SGRawValuePointer<float>(&_height_above_ground));
100 _node->tie("debug/tow-end-height-above-ground",SGRawValuePointer<float>(&_winch_height_above_ground));
101 _node->tie("debug/tow-rel-lo-pos",SGRawValuePointer<float>(&_loPosFrac));
102 _node->tie("debug/tow-lowest-pos-height",SGRawValuePointer<float>(&_lowest_tow_height));
103 _node->tie("is-slave",SGRawValuePointer<bool>(&_isSlave));
104 _node->tie("speed-in-tow-direction",SGRawValuePointer<float>(&_speed_in_tow_direction));
105 _node->tie("mp-auto-connect-period",SGRawValuePointer<float>(&_mpAutoConnectPeriod));
106 _node->tie("mp-time-lag",SGRawValuePointer<float>(&_mp_time_lag));
107 _node->setStringValue("tow/node","");
108 _node->setStringValue("tow/connected-to-ai-or-mp-callsign");
109 _node->setBoolValue("broken",false);
117 _node->untie("tow/length");
118 _node->untie("tow/elastic-constant");
119 _node->untie("tow/weight-per-m-kg-m");
120 _node->untie("tow/brake-force");
121 _node->untie("winch/max-speed-m-s");
122 _node->untie("winch/rel-speed");
123 _node->untie("winch/initial-tow-length-m");
124 _node->untie("winch/min-tow-length-m");
125 _node->untie("winch/max-tow-length-m");
126 _node->untie("winch/global-pos-x");
127 _node->untie("winch/global-pos-y");
128 _node->untie("winch/global-pos-z");
129 _node->untie("winch/max-power");
130 _node->untie("winch/max-force");
131 _node->untie("winch/actual-force");
132 _node->untie("tow/end-force-x");
133 _node->untie("tow/end-force-y");
134 _node->untie("tow/end-force-z");
135 _node->untie("force");
136 _node->untie("open");
137 _node->untie("force-is-calculated-by-other");
138 _node->untie("local-pos-x");
139 _node->untie("local-pos-y");
140 _node->untie("local-pos-z");
141 _node->untie("tow/dist");
142 _node->untie("tow/dist-time-lag-corrected");
143 _node->untie("tow/connected-to-property-node");
144 _node->untie("tow/connected-to-mp-node");
145 _node->untie("tow/connected-to-ai-node");
146 _node->untie("tow/connected-to-ai-or-mp-id");
147 _node->untie("debug/hitch-height-above-ground");
148 _node->untie("debug/tow-end-height-above-ground");
149 _node->untie("debug/tow-rel-lo-pos");
150 _node->untie("debug/tow-lowest-pos-height");
151 _node->untie("is-slave");
152 _node->untie("speed-in-tow-direction");
153 _node->untie("mp-auto-connect-period");
154 _node->untie("mp-time-lag");
159 void Hitch::setPosition(float* position)
162 for(i=0; i<3; i++) _pos[i] = position[i];
165 void Hitch::setTowLength(float length)
170 void Hitch::setOpen(bool isOpen)
172 //test if we already processed this before
173 //without this test a binded property could
174 //try to close the Hitch every run
175 //it will close, if we are near the end
176 //e.g. if we are flying over the parked
178 if (isOpen==_last_wish)
184 void Hitch::setTowElasticConstant(float sc)
186 _towElasticConstant=sc;
189 void Hitch::setTowBreakForce(float bf)
194 void Hitch::setWinchMaxForce(float f)
199 void Hitch::setTowWeightPerM(float rw)
204 void Hitch::setWinchMaxSpeed(float mws)
209 void Hitch::setWinchRelSpeed(float rws)
214 void Hitch::setWinchPosition(double *winchPosition)//in global coordinates!
216 for (int i=0; i<3;i++)
217 _winchPos[i]=winchPosition[i];
220 void Hitch::setMpAutoConnectPeriod(float dt)
222 _mpAutoConnectPeriod=dt;
225 void Hitch::setForceIsCalculatedByOther(bool b)
227 _forceIsCalculatedByMaster=b;
230 std::string Hitch::getConnectedPropertyNode() const
233 return _towEndNode->getDisplayName();
235 return std::string("");
238 void Hitch::setConnectedPropertyNode(const char *nodename)
240 _towEndNode=fgGetNode(nodename,false);
243 void Hitch::setWinchPositionAuto(bool doit)
245 static bool lastState=false;
257 // The ground plane transformed to the local frame.
259 _state->planeGlobalToLocal(_global_ground, ground);
262 //find a normalized vector pointing forward parallel to the ground
266 Math::cross3(ground,help,help);
267 //multiplay by initial tow length;
268 //reduced by 1m to be able to close the
269 //hitch either if the glider slips backwards a bit
270 Math::mul3((_winchInitialTowLength-1.),help,help);
271 //add to the actual pos
272 Math::add3(_pos,help,lWinchPos);
273 //put it onto the ground plane
274 Math::mul3(ground[3],ground,help);
275 Math::add3(lWinchPos,help,lWinchPos);
277 _state->posLocalToGlobal(lWinchPos,_winchPos);
278 _towLength=_winchInitialTowLength;
279 fgSetString("/sim/messages/pilot", "Connected to winch!");
282 _node->setBoolValue("broken",false);
284 //set the dist value (if not, the hitch would open in the next calcforce run
286 Math::sub3(lWinchPos,_pos,delta);
287 _dist=Math::mag3(delta);
290 void Hitch::findBestAIObject(bool doit,bool running_as_autoconnect)
292 static bool lastState=false;
295 if (!running_as_autoconnect)
297 //if this function is binded to an input, it will be called every frame as long as the key is pressed.
298 //therefore wait for a key-release before running it again.
309 _state->posLocalToGlobal(_pos,gpos);
310 double bestdist=_towLength*_towLength;//squared!
311 _towEndIsConnectedToProperty=false;
312 SGPropertyNode * ainode = fgGetNode("/ai/models",false);
314 char myCallsign[256]="***********";
315 if (running_as_autoconnect)
318 SGPropertyNode *cs=fgGetNode("/sim/multiplay/callsign",false);
321 strncpy(myCallsign,cs->getStringValue(),256);
324 //reset tow length for search radius. Lentgh will be later copied from master
325 _towLength=_winchInitialTowLength;
328 vector <SGPropertyNode_ptr> nodes;//<SGPropertyNode_ptr>
329 for (int i=0;i<ainode->nChildren();i++)
331 SGPropertyNode * n=ainode->getChild(i);
332 _nodeIsMultiplayer = strncmp("multiplayer",n->getName(),11)==0;
333 _nodeIsAiAircraft = strncmp("aircraft",n->getName(),8)==0;
334 if (!(_nodeIsMultiplayer || _nodeIsAiAircraft))
336 if (running_as_autoconnect)
338 if (!_nodeIsMultiplayer)
340 if(n->getBoolValue("sim/hitches/aerotow/open",true)) continue;
341 if(strncmp(myCallsign,n->getStringValue("sim/hitches/aerotow/tow/connected-to-ai-or-mp-callsign"),255)!=0)
345 pos[0]=n->getDoubleValue("position/global-x",0);
346 pos[1]=n->getDoubleValue("position/global-y",0);
347 pos[2]=n->getDoubleValue("position/global-z",0);
349 for (int j=0;j<3;j++)
350 dist+=(pos[j]-gpos[j])*(pos[j]-gpos[j]);
355 _towEndIsConnectedToProperty=true;
356 //_node->setStringValue("tow/node",n->getPath());
357 _node->setStringValue("tow/node",n->getDisplayName());
358 _nodeID=n->getIntValue("id",0);
359 _node->setStringValue("tow/connected-to-ai-or-mp-callsign",n->getStringValue("callsign"));
366 if (!running_as_autoconnect)
368 std::stringstream message;
369 message<<_node->getStringValue("tow/connected-to-ai-or-mp-callsign")
370 <<", I am on your hook, distance "<<Math::sqrt(bestdist)<<" meter.";
371 fgSetString("/sim/messages/pilot", message.str().c_str());
375 std::stringstream message;
376 message<<_node->getStringValue("tow/connected-to-ai-or-mp-callsign")
377 <<": I am on your hook, distance "<<Math::sqrt(bestdist)<<" meter.";
378 fgSetString("/sim/messages/ai-plane", message.str().c_str());
380 if (running_as_autoconnect)
382 //set the dist value to some value below the tow lentgh (if not, the hitch
383 //would open in the next calc force run
384 _dist=_towLength*0.5;
385 _mp_open_last_state=true;
388 if (!running_as_autoconnect)
390 fgSetString("/sim/messages/atc", "Sorry, no aircraft for aerotow!");
394 void Hitch::setWinchInitialTowLength(float length)
396 _winchInitialTowLength=length;
399 void Hitch::setWinchPower(float power)
404 void Hitch::setWinchMaxTowLength(float length)
406 _winchMaxTowLength=length;
409 void Hitch::setWinchMinTowLength(float length)
411 _winchMinTowLength=length;
414 void Hitch::setGlobalGround(double *global_ground, float *global_vel)
417 for(i=0; i<4; i++) _global_ground[i] = global_ground[i];
418 for(i=0; i<3; i++) _global_vel[i] = global_vel[i];
421 void Hitch::getPosition(float* out)
424 for(i=0; i<3; i++) out[i] = _pos[i];
427 float Hitch::getTowLength(void)
432 void Hitch::calcForce(Ground *g_cb, RigidBody* body, State* s)
434 float lWinchPos[3],delta[3],deltaN[3];
436 s->posGlobalToLocal(_winchPos,lWinchPos);
437 Math::sub3(lWinchPos,_pos,delta);
438 if(!_towEndIsConnectedToProperty)
439 _dist=Math::mag3(delta);
441 _dist=Math::mag3(lWinchPos); //use the aircraft center as reference for distance calculation
442 //this position is transferred to the MP-Aircraft.
443 //With this trick, both player in aerotow get the same length
444 Math::unit3(delta,deltaN);
446 s->velGlobalToLocal(s->v,lvel);
447 _speed_in_tow_direction=Math::dot3(lvel,deltaN);
448 if (_towEndIsConnectedToProperty && _nodeIsMultiplayer)
450 float mp_delta_dist_due_to_time_lag=0.5*_mp_time_lag*(-_mp_v+_speed_in_tow_direction);
451 _timeLagCorrectedDist=_dist+mp_delta_dist_due_to_time_lag;
452 if(_forceIsCalculatedByMaster && !_open)
454 s->velGlobalToLocal(_mp_force,_force);
459 _timeLagCorrectedDist=_dist;
462 _force[0]=_force[1]=_force[2]=0;
467 _forceMagnitude=(_dist-_towLength)/_towLength*_towElasticConstant;
469 _forceMagnitude=2*_towBrakeForce;
472 if(_forceMagnitude>=_towBrakeForce)
476 _node->setBoolValue("broken",true);
477 _force[0]=_force[1]=_force[2]=0;
478 _towEndForce[0]=_towEndForce[1]=_towEndForce[2]=0;
479 _reportTowEndForce[0]=_reportTowEndForce[1]=_reportTowEndForce[2]=0;
482 Math::mul3(_forceMagnitude,deltaN,_force);
483 Math::mul3(-1.,_force,_towEndForce);
484 _winchActualForce=_forceMagnitude; //missing: gravity on this end and friction
485 //Add the gravitiy of the rope.
486 //calculate some numbers:
487 float grav_force=_towWeightPerM*_towLength*9.81;
488 //the length of the gravity-expanded row:
489 float leng=_towLength+grav_force*_towLength/_towElasticConstant;
490 // The ground plane transformed to the local frame.
492 s->planeGlobalToLocal(_global_ground, ground);
494 // The velocity of the contact patch transformed to local coordinates.
496 //s->velGlobalToLocal(_global_vel, glvel);
498 _height_above_ground = ground[3] - Math::dot3(_pos, ground);
500 //the same for the winch-pos (the pos of the tow end)
501 _winch_height_above_ground = ground[3] - Math::dot3(lWinchPos, ground);
503 //the frac of the grav force acting on _pos:
504 float grav_frac=0.5*(1+(_height_above_ground-_winch_height_above_ground)/leng);
505 grav_frac=Math::clamp(grav_frac,0,1);
506 float grav_frac_tow_end=1-grav_frac;
507 //reduce grav_frac, if the tow has ground contact.
508 if (_height_above_ground<leng) //if not, the tow can not be on ground
510 float fa[3],fb[3],fg[3];
511 //the grav force an the hitch position:
512 Math::mul3(-grav_frac*grav_force,ground,fg);
513 //the total force on hitch postion:
514 Math::add3(fg,_force,fa);
515 //the grav force an the tow end position:
516 Math::mul3(-(1-grav_frac)*grav_force,ground,fg);
517 //the total force on tow end postion:
518 //note: sub: _force on tow-end is negative of force on hitch postion
519 Math::sub3(fg,_force,fb);
520 float fa_=Math::mag3(fa);
521 float fb_=Math::mag3(fb);
522 float stretchedTowLen;
523 stretchedTowLen=_towLength*(1.+(fa_+fb_)/(2*_towElasticConstant));
524 //the relative position of the lowest postion of the tow:
526 _loPosFrac=fa_/(fa_+fb_);
529 //dist to tow-end parallel to ground
532 //Math::cross3(delta,ground,help);//as long as we calculate the dist without _pos, od it with lWinchpos, the dist to our center....
533 Math::cross3(lWinchPos,ground,help);
534 ground_dist=Math::mag3(help);
535 //height of lowest tow pos (relative to _pos)
536 _lowest_tow_height=_loPosFrac*Math::sqrt(Math::abs(stretchedTowLen*stretchedTowLen-ground_dist*ground_dist));
537 if (_height_above_ground<_lowest_tow_height)
539 if (_height_above_ground>1e-3)
540 grav_frac*=_height_above_ground/_lowest_tow_height;
544 if (_winch_height_above_ground<(_lowest_tow_height-_height_above_ground+_winch_height_above_ground))
546 if (_winch_height_above_ground>1e-3)
547 grav_frac_tow_end*=_winch_height_above_ground/
548 (_lowest_tow_height-_height_above_ground+_winch_height_above_ground);
553 else _lowest_tow_height=_loPosFrac=-1; //for debug output
554 float grav_force_v[3];
555 Math::mul3(grav_frac*grav_force,ground,grav_force_v);
556 Math::add3(grav_force_v,_force,_force);
557 _forceMagnitude=Math::mag3(_force);
558 //the same for the tow end:
559 Math::mul3(grav_frac_tow_end*grav_force,ground,grav_force_v);
560 Math::add3(grav_force_v,_towEndForce,_towEndForce);
561 s->velLocalToGlobal(_towEndForce,_towEndForce);
563 if(_forceMagnitude>=_towBrakeForce)
567 _node->setBoolValue("broken",true);
568 _force[0]=_force[1]=_force[2]=0;
569 _towEndForce[0]=_towEndForce[1]=_towEndForce[2]=0;
575 // Computed values: total force
576 void Hitch::getForce(float* force, float* off)
578 Math::set3(_force, force);
579 Math::set3(_pos, off);
582 void Hitch::integrate (float dt)
584 //check if hitch has opened or closed, if yes: message
585 if (_open !=_oldOpen)
589 if (_dist>_towLength*1.00001)
591 std::stringstream message;
592 message<<"Could not lock hitch (tow length is insufficient) on hitch "
593 <<_node->getName()<<" "<<_node->getIndex()<<"!";
594 fgSetString("/sim/messages/pilot", message.str().c_str());
598 _node->setBoolValue("broken",false);
600 std::stringstream message;
601 if (_node->getBoolValue("broken",false)&&_open)
602 message<<"Oh no, the tow is broken";
604 message<<(_open?"Opened hitch ":"Locked hitch ")<<_node->getName()<<" "<<_node->getIndex()<<"!";
605 fgSetString("/sim/messages/pilot", message.str().c_str());
609 //check, if tow end should be searched in all MP-aircrafts
610 if(_open && _mpAutoConnectPeriod)
613 _timeToNextAutoConnectTry-=dt;
614 if ((_timeToNextAutoConnectTry>_mpAutoConnectPeriod) || (_timeToNextAutoConnectTry<0))
616 _timeToNextAutoConnectTry=_mpAutoConnectPeriod;
617 //search for MP-Aircraft, which is towed with us
618 findBestAIObject(true,true);
621 //check, if tow end can be modified by property, if yes: update
622 if(_towEndIsConnectedToProperty)
626 //_towEndNode=fgGetNode(_node->getStringValue("tow/node"), false);
628 strncpy(towNode,_node->getStringValue("tow/node"),256);
630 _towEndNode=fgGetNode("ai/models")->getNode(towNode, false);
631 //AI and multiplayer objects seem to change node?
632 //Check if we have the right one by callsign
633 if (_nodeIsMultiplayer || _nodeIsAiAircraft)
635 char MPcallsign[256]="";
637 MPc=_node->getStringValue("tow/connected-to-ai-or-mp-callsign");
640 strncpy(MPcallsign,MPc,256);
643 if (((_towEndNode)&&(strncmp(_towEndNode->getStringValue("callsign"),MPcallsign,255)!=0))||!_towEndNode)
645 _timeToNextReConnectTry-=dt;
646 if((_timeToNextReConnectTry<0)||(_timeToNextReConnectTry>10))
648 _timeToNextReConnectTry=10;
649 SGPropertyNode * ainode = fgGetNode("/ai/models",false);
652 for (int i=0;i<ainode->nChildren();i++)
654 SGPropertyNode * n=ainode->getChild(i);
655 if(_nodeIsMultiplayer?strncmp("multiplayer",n->getName(),11)==0:strncmp("aircraft",n->getName(),8))
656 if (strcmp(n->getStringValue("callsign"),MPcallsign)==0)//found
659 //_node->setStringValue("tow/node",n->getPath());
660 _node->setStringValue("tow/node",n->getDisplayName());
669 _winchPos[0]=_towEndNode->getDoubleValue("position/global-x",_winchPos[0]);
670 _winchPos[1]=_towEndNode->getDoubleValue("position/global-y",_winchPos[1]);
671 _winchPos[2]=_towEndNode->getDoubleValue("position/global-z",_winchPos[2]);
672 _mp_lpos[0]=_towEndNode->getFloatValue("sim/hitches/aerotow/local-pos-x",0);
673 _mp_lpos[1]=_towEndNode->getFloatValue("sim/hitches/aerotow/local-pos-y",0);
674 _mp_lpos[2]=_towEndNode->getFloatValue("sim/hitches/aerotow/local-pos-z",0);
675 _mp_dist=_towEndNode->getFloatValue("sim/hitches/aerotow/tow/dist");
676 _mp_v=_towEndNode->getFloatValue("sim/hitches/aerotow/speed-in-tow-direction");
677 _mp_force[0]=_towEndNode->getFloatValue("sim/hitches/aerotow/tow/end-force-x",0);
678 _mp_force[1]=_towEndNode->getFloatValue("sim/hitches/aerotow/tow/end-force-y",0);
679 _mp_force[2]=_towEndNode->getFloatValue("sim/hitches/aerotow/tow/end-force-z",0);
683 #define gf(a,b) a=_towEndNode->getFloatValue(b,a)
684 #define gb(a,b) a=_towEndNode->getBoolValue(b,a)
685 gf(_towLength,"sim/hitches/aerotow/tow/length");
686 gf(_towElasticConstant,"sim/hitches/aerotow/tow/elastic-constant");
687 gf(_towWeightPerM,"sim/hitches/aerotow/tow/weight-per-m-kg-m");
688 gf(_towBrakeForce,"sim/hitches/aerotow/brake-force");
689 gb(_open,"sim/hitches/aerotow/open");
690 gb(_mp_is_slave,"sim/hitches/aerotow/is-slave");
693 if (_mp_is_slave) _isSlave=false; //someone should be master
697 //check if other has opened hitch, but is neccessary, that it was closed before
698 bool mp_open=_towEndNode->getBoolValue("sim/hitches/aerotow/open",_mp_open_last_state);
699 if (mp_open != _mp_open_last_state) //state has changed
701 _mp_open_last_state=mp_open; //store that value
707 std::stringstream message;
708 message<<_node->getStringValue("tow/connected-to-ai-or-mp-callsign")
709 <<": I have released the tow!";
710 fgSetString("/sim/messages/ai-plane", message.str().c_str());
715 //try to calculate the time lag
716 if ((_mp_last_reported_dist!=_mp_dist)||(_mp_last_reported_v!=_mp_v)) //new data;
718 _mp_last_reported_dist=_mp_dist;
719 _mp_last_reported_v=_mp_v;
720 float total_v=-_mp_v+_speed_in_tow_direction;//mp has opposite tow direction
721 float abs_v=Math::abs(total_v);
724 float actual_time_lag_guess=(_mp_dist-_dist)/total_v;
725 //check, if it sounds ok
726 if((actual_time_lag_guess>0)&&(actual_time_lag_guess<5))
728 float frac=abs_v*0.01;
729 if (frac>0.05) frac=0.05;
730 // if we are slow, the guess of the lag can be rather wrong. as faster we are
731 // the better the guess. Therefore frac is proportiona to the speed. Clamp it
733 _mp_time_lag=(1-frac)*_mp_time_lag+frac*actual_time_lag_guess;
740 //set the _reported_tow_end_force
741 Math::set3(_towEndForce,_reportTowEndForce);
744 if (_winchRelSpeed==0) return;
745 float factor=1,offset=0;
746 if (_winchActualForce>_winchMaxForce)
747 offset=-(_winchActualForce-_winchMaxForce)/_winchMaxForce*20;
748 if (_winchRelSpeed>0.01) // to avoit div by zero
750 float maxForcePowerLimit=_winchPower/(_winchRelSpeed*_winchMaxSpeed);
751 if (_winchActualForce>maxForcePowerLimit)
752 factor-=(_winchActualForce-maxForcePowerLimit)/maxForcePowerLimit;
754 _towLength-=dt*(factor*_winchRelSpeed+offset)*_winchMaxSpeed;
755 if (_towLength<=_winchMinTowLength)
757 if (_winchRelSpeed<0)
759 _towLength=_winchMinTowLength;
762 if (_towLength>=_winchMaxTowLength)
764 if (_winchRelSpeed<0)
766 _towLength=_winchMaxTowLength;
774 }; // namespace yasim