1 // FGAILocalTraffic - AIEntity derived class with enough logic to
2 // fly and interact with the traffic pattern.
4 // Written by David Luff, started March 2002.
6 // Copyright (C) 2002 David C. Luff - david.luff@nottingham.ac.uk
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., 675 Mass Ave, Cambridge, MA 02139, USA.
26 #include <Main/globals.hxx>
27 #include <Main/location.hxx>
28 #include <Scenery/scenery.hxx>
29 #include <simgear/math/point3d.hxx>
30 #include <simgear/math/sg_geodesy.hxx>
31 #include <simgear/misc/sg_path.hxx>
38 #include "AILocalTraffic.hxx"
39 #include "ATCutils.hxx"
41 FGAILocalTraffic::FGAILocalTraffic() {
42 //Hardwire initialisation for now - a lot of this should be read in from config eventually
44 best_rate_of_climb_speed = 70.0;
46 //nominal_climb_speed;
48 //nominal_circuit_speed;
51 nominal_descent_rate = 500.0;
52 nominal_final_speed = 65.0;
53 //nominal_approach_speed;
54 //stall_speed_landing_config;
55 nominalTaxiSpeed = 8.0;
57 // Init the property nodes
58 wind_from_hdg = fgGetNode("/environment/wind-from-heading-deg", true);
59 wind_speed_knots = fgGetNode("/environment/wind-speed-kts", true);
63 FGAILocalTraffic::~FGAILocalTraffic() {
66 void FGAILocalTraffic::Init() {
67 // Hack alert - Hardwired path!!
68 string planepath = "Aircraft/c172/Models/c172-dpm.ac";
69 SGPath path = globals->get_fg_root();
70 path.append(planepath);
71 aip.init(planepath.c_str());
73 globals->get_scenery()->get_scene_graph()->addKid(aip.getSceneGraph());
74 // is it OK to leave it like this until the first time transform is called?
75 // Really ought to be started in a parking space unless otherwise specified?
77 // Find the tower frequency - this is dependent on the ATC system being initialised before the AI system
78 // FIXME - ATM this is hardwired.
81 if(globals->get_ATC_mgr()->GetAirportATCDetails((string)airportID, &a)) {
82 if(a.tower_freq) { // Has a tower
83 tower = (FGTower*)globals->get_ATC_mgr()->GetATCPointer((string)airportID, TOWER); // Maybe need some error checking here
84 freq = (double)tower->get_freq() / 100.0;
85 //cout << "***********************************AILocalTraffic freq = " << freq << '\n';
87 // Check CTAF, unicom etc
90 //cout << "Unable to find airport details in FGAILocalTraffic::Init()\n";
93 // Initiallise the FGAirportData structure
94 // This needs a complete overhaul soon - what happens if we have 2 AI planes at same airport - they don't both need a structure
95 // This needs to be handled by the ATC manager or similar so only one set of physical data per airport is instantiated
96 // ie. TODO TODO FIXME FIXME
101 // Commands to do something from higher level logic
102 void FGAILocalTraffic::FlyCircuits(int numCircuits, bool tag) {
103 circuitsToFly += numCircuits;
106 //At the moment we'll assume that we are always finished previous circuits when called,
107 //And just teleport to the threshold to start.
108 //This is a hack though, we need to check where we are and taxi out if appropriate.
109 operatingState = IN_PATTERN;
110 #define DCL_KEMT true
111 //#define DCL_KPAO true
113 // Hardwire to KEMT for now
114 // Hardwired points at each end of KEMT runway
115 Point3D P010(-118.037483, 34.081358, 296 * SG_FEET_TO_METER);
116 Point3D P190(-118.032308, 34.090456, 299.395263 * SG_FEET_TO_METER);
118 bool d010 = true; // use this to change the hardwired runway direction
120 rwy.threshold_pos = P010;
122 rwy.hdg = 25.32; //from default.apt
124 patternDirection = -1; // Left
125 pos.setelev(rwy.threshold_pos.elev() + (-8.5 * SG_FEET_TO_METER)); // This is a complete hack - the rendered runway takes the underlying scenery elev rather than the published runway elev so I should use height above terrain or something.
127 rwy.threshold_pos = P190;
131 patternDirection = 1; // Right
132 pos.setelev(rwy.threshold_pos.elev() + (-0.0 * SG_FEET_TO_METER)); // This is a complete hack - the rendered runway takes the underlying scenery elev rather than the published runway elev so I should use height above terrain or something.
135 //KPAO - might be a better choice since its in the default scenery
136 //Hardwire it to the default (no wind) direction
137 Point3D threshold_end(-122.1124358, 37.45848783, 6.8 * SG_FEET_TO_METER); // These positions are from airnav.com and don't quite seem to correspond with the sim scenery
138 Point3D takeoff_end(-122.1176522, 37.463752, 6.7 * SG_FEET_TO_METER);
139 rwy.threshold_pos = threshold_end;
142 patternDirection = 1; // Right
143 pos.setelev(rwy.threshold_pos.elev() + (-0.0 * SG_FEET_TO_METER)); // This is a complete hack - the rendered runway takes the underlying scenery elev rather than the published runway elev so I should use height above terrain or something.
146 //rwy.threshold_pos.setlat(34.081358);
147 //rwy.threshold_pos.setlon(-118.037483);
148 //rwy.mag_hdg = 12.0;
149 //rwy.mag_var = 14.0;
150 //rwy.hdg = rwy.mag_hdg + rwy.mag_var;
151 //rwy.threshold_pos.setelev(296 * SG_FEET_TO_METER);
153 // Initial position on threshold for now
154 // TODO - check wind / default runway
155 pos.setlat(rwy.threshold_pos.lat());
156 pos.setlon(rwy.threshold_pos.lon());
165 // Now set the position of the plane and then re-get the elevation!! (Didn't work - elev always returned as zero) :-(
166 //aip.setPosition(pos.lon(), pos.lat(), pos.elev() * SG_METER_TO_FEET);
167 //cout << "*********************** elev in FGAILocalTraffic = " << aip.getFGLocation()->get_cur_elev_m() << '\n';
169 // Set the projection for the local area
170 ortho.Init(rwy.threshold_pos, rwy.hdg);
171 rwy.end1ortho = ortho.ConvertToLocal(rwy.threshold_pos); // should come out as zero
172 // Hardwire to KEMT for now
173 rwy.end2ortho = ortho.ConvertToLocal(takeoff_end);
174 //cout << "*********************************************************************************\n";
175 //cout << "*********************************************************************************\n";
176 //cout << "*********************************************************************************\n";
177 //cout << "end1ortho = " << rwy.end1ortho << '\n';
178 //cout << "end2ortho = " << rwy.end2ortho << '\n'; // end2ortho.x() should be zero or thereabouts
183 // Run the internal calculations
184 void FGAILocalTraffic::Update(double dt) {
185 //std::cout << "In FGAILocalTraffic::Update\n";
186 // Hardwire flying traffic pattern for now - eventually also needs to be able to taxi to and from runway and GA parking area.
187 switch(operatingState) {
189 FlyTrafficPattern(dt);
202 //cout << "elev in FGAILocalTraffic = " << aip.getFGLocation()->get_cur_elev_m() << '\n';
203 // This should become if(the plane has moved) then Transform()
206 // Fly a traffic pattern
207 // FIXME - far too much of the mechanics of turning, rolling, accellerating, descending etc is in here.
208 // Move it out to FGAIPlane and have FlyTrafficPattern just specify what to do, not the implementation.
209 void FGAILocalTraffic::FlyTrafficPattern(double dt) {
210 // Need to differentiate between in-air (IAS governed) and on-ground (vel governed)
211 // Take-off is an interesting case - we are on the ground but takeoff speed is IAS governed.
212 bool inAir = true; // FIXME - possibly make into a class variable
214 static bool transmitted = false; // FIXME - this is a hack
217 // Wind has two effects - a mechanical one in that IAS translates to a different vel, and the hdg != track,
218 // but also a piloting effect, in that the AI must be able to descend at a different rate in order to hit the threshold.
220 //cout << "dt = " << dt << '\n';
222 // ack - I can't remember how long a rate 1 turn is meant to take.
223 double turn_time = 60.0; // seconds - TODO - check this guess
224 double turn_circumference;
226 Point3D orthopos = ortho.ConvertToLocal(pos); // ortho position of the plane
227 //cout << "runway elev = " << rwy.threshold_pos.elev() << ' ' << rwy.threshold_pos.elev() * SG_METER_TO_FEET << '\n';
228 //cout << "elev = " << pos.elev() << ' ' << pos.elev() * SG_METER_TO_FEET << '\n';
230 // HACK FOR TESTING - REMOVE
231 //cout << "Calling ExitRunway..." << endl;
232 //ExitRunway(orthopos);
237 double wind_from = wind_from_hdg->getDoubleValue();
238 double wind_speed = wind_speed_knots->getDoubleValue();
248 IAS = vel + (cos((hdg - wind_from) * DCL_DEGREES_TO_RADIANS) * wind_speed);
252 IAS = best_rate_of_climb_speed;
258 if((pos.elev() - rwy.threshold_pos.elev()) * SG_METER_TO_FEET > 600) {
263 track += (360.0 / turn_time) * dt * patternDirection;
264 Bank(25.0 * patternDirection);
265 if((track < (rwy.hdg - 89.0)) || (track > (rwy.hdg + 89.0))) {
271 track = rwy.hdg + (90.0 * patternDirection);
272 if((pos.elev() - rwy.threshold_pos.elev()) * SG_METER_TO_FEET > 1000) {
275 IAS = 80.0; // FIXME - use smooth transistion to new speed
277 // turn 1000m out for now
278 if(fabs(orthopos.x()) > 980) {
283 track += (360.0 / turn_time) * dt * patternDirection;
284 Bank(25.0 * patternDirection);
285 // just in case we didn't make height on crosswind
286 if((pos.elev() - rwy.threshold_pos.elev()) * SG_METER_TO_FEET > 1000) {
289 IAS = 80.0; // FIXME - use smooth transistion to new speed
291 if((track < (rwy.hdg - 179.0)) || (track > (rwy.hdg + 179.0))) {
299 track = rwy.hdg - (180 * patternDirection); //should tend to bring track back into the 0->360 range
300 // just in case we didn't make height on crosswind
301 if((pos.elev() - rwy.threshold_pos.elev()) * SG_METER_TO_FEET > 1000) {
304 IAS = 90.0; // FIXME - use smooth transistion to new speed
306 if((orthopos.y() < 0) && (!transmitted)) {
307 TransmitPatternPositionReport();
310 if(orthopos.y() < -480) {
311 slope = -4.0; // FIXME - calculate to descent at 500fpm and hit the threshold (taking wind into account as well!!)
315 if(orthopos.y() < -980) {
323 track += (360.0 / turn_time) * dt * patternDirection;
324 Bank(25.0 * patternDirection);
325 if(fabs(rwy.hdg - track) < 91.0) {
332 TransmitPatternPositionReport();
335 track = rwy.hdg - (90 * patternDirection);
336 slope = -6.0; // FIXME - calculate to descent at 500fpm and hit the threshold
338 IAS = 70.0; // FIXME - slowdown gradually
339 // Try and arrange to turn nicely onto base
340 turn_circumference = IAS * 0.514444 * turn_time;
341 //Hmmm - this is an interesting one - ground vs airspeed in relation to turn radius
342 //We'll leave it as a hack with IAS for now but it needs revisiting.
344 turn_radius = turn_circumference / (2.0 * DCL_PI);
345 if(fabs(orthopos.x()) < (turn_radius + 50)) {
352 track += (360.0 / turn_time) * dt * patternDirection;
353 Bank(25.0 * patternDirection);
354 if(fabs(track - rwy.hdg) < 0.6) {
356 vel = nominal_final_speed;
362 TransmitPatternPositionReport();
365 // Try and track the extended centreline
366 track = rwy.hdg - (0.2 * orthopos.x());
367 //cout << "orthopos.x() = " << orthopos.x() << " hdg = " << hdg << '\n';
368 if(pos.elev() <= rwy.threshold_pos.elev()) {
369 pos.setelev(rwy.threshold_pos.elev());// + (-8.5 * SG_FEET_TO_METER)); // This is a complete hack - the rendered runway takes the underlying scenery elev rather than the published runway elev so I should use height above terrain or something.
378 double dveldt = -5.0;
380 // FIXME - differentiate between touch and go and full stops
382 //cout << "Vel <= 15.0, circuitsToFly = " << circuitsToFly << endl;
383 if(circuitsToFly <= 0) {
384 //cout << "Calling ExitRunway..." << endl;
385 ExitRunway(orthopos);
388 //cout << "Taking off again..." << endl;
397 // FIXME - at the moment this is a bit screwy
398 // The velocity correction is applied based on the relative headings.
399 // Then the heading is changed based on the velocity.
400 // Which comes first, the chicken or the egg?
401 // Does it really matter?
403 // Apply wind to ground-relative velocity if in the air
404 vel = IAS - (cos((hdg - wind_from) * DCL_DEGREES_TO_RADIANS) * wind_speed);
405 //crab = f(track, wind, vel);
406 // The vector we need to fly is our desired vector minus the wind vector
407 // TODO - we probably ought to use plib's built in vector types and operations for this
408 // ie. There's almost *certainly* a better way to do this!
409 double gxx = vel * sin(track * DCL_DEGREES_TO_RADIANS); // Plane desired velocity x component wrt ground
410 double gyy = vel * cos(track * DCL_DEGREES_TO_RADIANS); // Plane desired velocity y component wrt ground
411 double wxx = wind_speed * sin((wind_from + 180.0) * DCL_DEGREES_TO_RADIANS); // Wind velocity x component
412 double wyy = wind_speed * cos((wind_from + 180.0) * DCL_DEGREES_TO_RADIANS); // Wind velocity y component
413 double axx = gxx - wxx; // Plane in-air velocity x component
414 double ayy = gyy - wyy; // Plane in-air velocity y component
415 // Now we want the angle between gxx and axx (which is the crab)
416 double maga = sqrt(axx*axx + ayy*ayy);
417 double magg = sqrt(gxx*gxx + gyy*gyy);
418 crab = acos((axx*gxx + ayy*gyy) / (maga * magg));
419 // At this point this works except we're getting the modulus of the angle
420 cout << "crab = " << crab << '\n';
422 // Make sure both headings are in the 0->360 circle in order to get sane differences
423 dclBoundHeading(wind_from);
424 dclBoundHeading(track);
425 if(track > wind_from) {
426 if((track - wind_from) <= 180) {
430 if((wind_from - track) >= 180) {
434 } else { // on the ground - crab dosen't apply
439 dist = vel * 0.514444 * dt;
440 pos = dclUpdatePosition(pos, track, slope, dist);
443 void FGAILocalTraffic::TransmitPatternPositionReport(void) {
444 // airport name + "traffic" + airplane callsign + pattern direction + pattern leg + rwy + ?
447 trns += tower->get_name();
449 // FIXME - add the callsign to the class variables
450 trns += "Trainer-two-five-charlie ";
451 if(patternDirection == 1) {
457 // We could probably get rid of this whole switch statement and just pass a string containing the leg from the FlyPattern function.
458 switch(leg) { // We'll assume that transmissions in turns are intended for next leg - do pilots ever call out that they are in the turn?
460 // Fall through to CROSSWIND
461 case CROSSWIND: // I don't think this case will be used here but it can't hurt to leave it in
462 trns += "crosswind ";
465 // Fall through to DOWNWIND
470 // Fall through to BASE
475 // Fall through to FINAL
476 case FINAL: // maybe this should include long/short final if appropriate?
479 default: // Hopefully this won't be used
483 // FIXME - I've hardwired the runway call as well!! (We could work this out from rwy heading and mag deviation)
484 trns += ConvertRwyNumToSpokenString(1);
486 // And add the airport name again
487 trns += tower->get_name();
492 void FGAILocalTraffic::ExitRunway(Point3D orthopos) {
493 //cout << "In ExitRunway" << endl;
494 //cout << "Runway ID is " << rwy.ID << endl;
495 node_array_type exitNodes = airport.GetExits(rwy.ID); //I suppose we ought to have some fallback for rwy with no defined exits?
496 //cout << "Got exits" << endl;
497 //cout << "Size of exits array is " << exitNodes.size() << endl;
498 //Find the next exit from orthopos.y
500 double dist = 100000; //ie. longer than any runway in existance
501 double backdist = 100000;
502 node_array_iterator nItr = exitNodes.begin();
503 node* rwyExit = *(exitNodes.begin());
504 int gateID; //This might want to be more persistant at some point
505 while(nItr != exitNodes.end()) {
506 d = ortho.ConvertToLocal((*nItr)->pos).y() - ortho.ConvertToLocal(pos).y(); //FIXME - consider making orthopos a class variable
513 if(fabs(d) < backdist) {
515 //TODO - need some logic here that if we don't get a forward exit we turn round and store the backwards one
520 //cout << "Calculated dist, dist = " << dist << endl;
521 // GetNodeList(exitNode->parking) and add to from here to exit node
522 gateID = airport.GetRandomGateID();
523 //cout << "gateID = " << gateID << endl;
524 in_dest = airport.GetGateNode(gateID);
525 //cout << "in_dest got..." << endl;
526 path = airport.GetPath(rwyExit, in_dest); //TODO - need to convert a and b to actual nodes!!
527 //cout << "path got..." << endl;
528 //cout << "Size of path is " << path.size() << endl;
529 taxiState = TD_INBOUND;
533 // Set the class variable nextTaxiNode to the next node in the path
534 // and update taxiPathPos, the class variable path iterator position
535 // TODO - maybe should return error codes to the calling function if we fail here
536 void FGAILocalTraffic::GetNextTaxiNode() {
537 //cout << "GetNextTaxiNode called " << endl;
538 //cout << "taxiPathPos = " << taxiPathPos << endl;
539 ground_network_path_iterator pathItr = path.begin() + taxiPathPos;
540 if(pathItr == path.end()) {
541 //cout << "ERROR IN AILocalTraffic::GetNextTaxiNode - no more nodes in path" << endl;
543 if((*pathItr)->struct_type == NODE) {
544 //cout << "ITS A NODE" << endl;
545 //*pathItr = new node;
546 nextTaxiNode = (node*)*pathItr;
550 //cout << "ITS NOT A NODE" << endl;
551 //The first item in found must have been an arc
552 //Assume for now that it was straight
555 if(pathItr == path.end()) {
556 //cout << "ERROR IN AILocalTraffic::GetNextTaxiNode - path ended with an arc" << endl;
557 } else if((*pathItr)->struct_type == NODE) {
558 nextTaxiNode = (node*)*pathItr;
561 // OOPS - two non-nodes in a row - that shouldn't happen ATM
562 //cout << "ERROR IN AILocalTraffic::GetNextTaxiNode - two non-nodes in sequence" << endl;
568 // StartTaxi - set up the taxiing state - call only at the start of taxiing
569 void FGAILocalTraffic::StartTaxi() {
570 //cout << "StartTaxi called" << endl;
571 operatingState = TAXIING;
574 //Set the desired heading
575 //Assume we are aiming for first node on path
576 //Eventually we may need to consider the fact that we might start on a curved arc and
577 //not be able to head directly for the first node.
578 GetNextTaxiNode(); // sets the class variable nextTaxiNode to the next taxi node!
579 desiredTaxiHeading = GetHeadingFromTo(pos, nextTaxiNode->pos);
580 //cout << "First taxi heading is " << desiredTaxiHeading << endl;
583 void FGAILocalTraffic::Taxi(double dt) {
584 //cout << "Taxi called" << endl;
585 // Logic - if we are further away from next point than turn radius then head for it
586 // If we have reached turning point then get next point and turn onto that heading
587 // Look out for the finish!!
589 Point3D orthopos = ortho.ConvertToLocal(pos); // ortho position of the plane
590 desiredTaxiHeading = GetHeadingFromTo(pos, nextTaxiNode->pos);
592 // HACK ALERT! - for now we will taxi at constant speed for straights and turns
594 // Remember that hdg is always equal to track when taxiing so we don't have to consider them both
595 double dist_to_go = dclGetHorizontalSeparation(pos, nextTaxiNode->pos); // we may be able to do this more cheaply using orthopos
596 //cout << "dist_to_go = " << dist_to_go << endl;
597 if((nextTaxiNode->type == GATE) && (dist_to_go <= 0.1)) {
601 operatingState = PARKED;
602 } else if((dist_to_go > taxiTurnRadius) || (nextTaxiNode->type == GATE)) {
603 // if the turn radius is r, and speed is s, then in a time dt we turn through
604 // ((s.dt)/(PI.r)) x 180 degrees
605 // or alternatively (s.dt)/r radians
606 //cout << "hdg = " << hdg << " desired taxi heading = " << desiredTaxiHeading << '\n';
607 if(fabs(hdg - desiredTaxiHeading) > 0.1) {
608 // Which is the quickest direction to turn onto heading?
609 if(desiredTaxiHeading > hdg) {
610 if((desiredTaxiHeading - hdg) <= 180) {
612 hdg += ((nominalTaxiSpeed * 0.514444 * dt) / (taxiTurnRadius * DCL_PI)) * 180.0;
613 // TODO - check that increments are less than the delta that we check for the right direction
614 // Probably need to reduce convergence speed as convergence is reached
616 hdg -= ((nominalTaxiSpeed * 0.514444 * dt) / (taxiTurnRadius * DCL_PI)) * 180.0;
619 if((hdg - desiredTaxiHeading) <= 180) {
621 hdg -= ((nominalTaxiSpeed * 0.514444 * dt) / (taxiTurnRadius * DCL_PI)) * 180.0;
622 // TODO - check that increments are less than the delta that we check for the right direction
623 // Probably need to reduce convergence speed as convergence is reached
625 hdg += ((nominalTaxiSpeed * 0.514444 * dt) / (taxiTurnRadius * DCL_PI)) * 180.0;
629 double vel = nominalTaxiSpeed;
630 //cout << "vel = " << vel << endl;
631 double dist = vel * 0.514444 * dt;
632 //cout << "dist = " << dist << endl;
634 //cout << "track = " << track << endl;
636 pos = dclUpdatePosition(pos, track, slope, dist);
637 //cout << "Updated position...\n";
638 // FIXME - HACK in absense of proper ground elevation determination
639 // Linearly interpolate altitude when taxiing between N and S extremes of orthopos
640 pos.setelev((287.5 + ((299.3 - 287.5) * fabs(orthopos.y() / 1000.0))) * SG_FEET_TO_METER);
642 // Time to turn (we've already checked it's not the end we're heading for).
643 // set the target node to be the next node which will prompt automatically turning onto
644 // the right heading in the stuff above, with the usual provisos applied.
646 // For now why not just recursively call this function?