1 // FGAIAircraft - FGAIBase-derived class creates an AI airplane
3 // Written by David Culp, started October 2003.
5 // Copyright (C) 2003 David P. Culp - davidculp2@comcast.net
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 #include <simgear/math/point3d.hxx>
26 #include <Main/fg_props.hxx>
27 #include <Main/globals.hxx>
28 #include <Scenery/scenery.hxx>
34 #include "AIAircraft.hxx"
37 // accel, decel, climb_rate, descent_rate, takeoff_speed, climb_speed,
38 // cruise_speed, descent_speed, land_speed
40 const FGAIAircraft::PERF_STRUCT FGAIAircraft::settings[] = {
42 {2.0, 2.0, 450.0, 1000.0, 70.0, 80.0, 100.0, 80.0, 60.0},
44 {4.0, 2.0, 3000.0, 1500.0, 110.0, 180.0, 250.0, 200.0, 100.0},
46 {5.0, 2.0, 3000.0, 1500.0, 140.0, 300.0, 430.0, 300.0, 130.0},
48 {7.0, 3.0, 4000.0, 2000.0, 150.0, 350.0, 500.0, 350.0, 150.0},
50 {5.0, 2.0, 3000.0, 1500.0, 140.0, 300.0, 430.0, 300.0, 130.0}
54 FGAIAircraft::FGAIAircraft(FGAIManager* mgr) {
56 _type_str = "aircraft";
63 // set heading and altitude locks
69 FGAIAircraft::~FGAIAircraft() {
73 bool FGAIAircraft::init() {
74 refuel_node = fgGetNode("systems/refuel/contact", true);
75 return FGAIBase::init();
78 void FGAIAircraft::bind() {
82 props->tie("controls/gear/gear-down",
83 SGRawValueFunctions<bool>(FGAIAircraft::_getGearDown));
85 props->getNode("controls/lighting/landing-lights", true)
86 ->alias("controls/gear/gear-down");
90 void FGAIAircraft::unbind() {
93 // props->untie("controls/gear/gear-down");
94 // props->getNode("controls/lighting/landing-lights")->unalias();
98 void FGAIAircraft::update(double dt) {
100 FGAIBase::update(dt);
105 void FGAIAircraft::SetPerformance(const PERF_STRUCT *ps) {
111 void FGAIAircraft::Run(double dt) {
113 FGAIAircraft::dt = dt;
115 if (fp) ProcessFlightPlan(dt);
117 double turn_radius_ft;
118 double turn_circum_ft;
119 double speed_north_deg_sec;
120 double speed_east_deg_sec;
121 double dist_covered_ft;
125 double speed_diff = tgt_speed - speed;
126 if (fabs(speed_diff) > 0.2) {
127 if (speed_diff > 0.0) speed += performance->accel * dt;
128 if (speed_diff < 0.0) {
130 speed -= performance->decel * dt * 3;
132 speed -= performance->decel * dt;
137 // convert speed to degrees per second
138 speed_north_deg_sec = cos( hdg / SG_RADIANS_TO_DEGREES )
139 * speed * 1.686 / ft_per_deg_lat;
140 speed_east_deg_sec = sin( hdg / SG_RADIANS_TO_DEGREES )
141 * speed * 1.686 / ft_per_deg_lon;
144 pos.setlat( pos.lat() + speed_north_deg_sec * dt);
145 pos.setlon( pos.lon() + speed_east_deg_sec * dt);
147 // adjust heading based on current bank angle
149 turn_radius_ft = 0.088362 * speed * speed
150 / tan( fabs(roll) / SG_RADIANS_TO_DEGREES );
151 turn_circum_ft = SGD_2PI * turn_radius_ft;
152 dist_covered_ft = speed * 1.686 * dt;
153 alpha = dist_covered_ft / turn_circum_ft * 360.0;
154 hdg += alpha * sign( roll );
155 if ( hdg > 360.0 ) hdg -= 360.0;
156 if ( hdg < 0.0) hdg += 360.0;
159 // adjust target bank angle if heading lock engaged
161 double bank_sense = 0.0;
162 double diff = fabs(hdg - tgt_heading);
163 if (diff > 180) diff = fabs(diff - 360);
164 double sum = hdg + diff;
165 if (sum > 360.0) sum -= 360.0;
166 if (fabs(sum - tgt_heading) < 1.0) {
167 bank_sense = 1.0; // right turn
169 bank_sense = -1.0; // left turn
172 tgt_roll = diff * bank_sense;
174 tgt_roll = 30.0 * bank_sense;
178 // adjust bank angle, use 9 degrees per second
179 double bank_diff = tgt_roll - roll;
180 if (fabs(bank_diff) > 0.2) {
181 if (bank_diff > 0.0) roll += 9.0 * dt;
182 if (bank_diff < 0.0) roll -= 9.0 * dt;
185 // adjust altitude (meters) based on current vertical speed (fpm)
186 altitude += vs / 60.0 * dt;
187 pos.setelev(altitude * SG_FEET_TO_METER);
188 double altitude_ft = altitude;
190 // find target vertical speed if altitude lock engaged
191 if (alt_lock && use_perf_vs) {
192 if (altitude_ft < tgt_altitude) {
193 tgt_vs = tgt_altitude - altitude_ft;
194 if (tgt_vs > performance->climb_rate)
195 tgt_vs = performance->climb_rate;
197 tgt_vs = tgt_altitude - altitude_ft;
198 if (tgt_vs < (-performance->descent_rate))
199 tgt_vs = -performance->descent_rate;
203 if (alt_lock && !use_perf_vs) {
204 double max_vs = 4*(tgt_altitude - altitude);
206 if (tgt_altitude < altitude) min_vs = -100.0;
207 if ((fabs(tgt_altitude - altitude) < 1500.0) &&
208 (fabs(max_vs) < fabs(tgt_vs))) tgt_vs = max_vs;
209 if (fabs(tgt_vs) < fabs(min_vs)) tgt_vs = min_vs;
212 // adjust vertical speed
213 double vs_diff = tgt_vs - vs;
214 if (fabs(vs_diff) > 10.0) {
217 if (vs > tgt_vs) vs = tgt_vs;
220 if (vs < tgt_vs) vs = tgt_vs;
224 // match pitch angle to vertical speed
231 //###########################//
232 // do calculations for radar //
233 //###########################//
234 double range_ft2 = UpdateRadar(manager);
236 //************************************//
238 //************************************//
241 if ( (range_ft2 < 250.0 * 250.0) &&
243 (elevation > 0.0) ) {
244 refuel_node->setBoolValue(true);
246 refuel_node->setBoolValue(false);
252 void FGAIAircraft::AccelTo(double speed) {
257 void FGAIAircraft::PitchTo(double angle) {
263 void FGAIAircraft::RollTo(double angle) {
269 void FGAIAircraft::YawTo(double angle) {
274 void FGAIAircraft::ClimbTo(double altitude) {
275 tgt_altitude = altitude;
280 void FGAIAircraft::TurnTo(double heading) {
281 tgt_heading = heading;
286 double FGAIAircraft::sign(double x) {
287 if ( x < 0.0 ) { return -1.0; }
291 void FGAIAircraft::SetFlightPlan(FGAIFlightPlan *f) {
295 void FGAIAircraft::ProcessFlightPlan( double dt ) {
296 FGAIFlightPlan::waypoint* prev = 0; // the one behind you
297 FGAIFlightPlan::waypoint* curr = 0; // the one ahead
298 FGAIFlightPlan::waypoint* next = 0; // the next plus 1
299 prev = fp->getPreviousWaypoint();
300 curr = fp->getCurrentWaypoint();
301 next = fp->getNextWaypoint();
304 if (!prev) { //beginning of flightplan, do this initialization once
305 fp->IncrementWaypoint();
306 prev = fp->getPreviousWaypoint(); //first waypoint
307 curr = fp->getCurrentWaypoint(); //second waypoint
308 next = fp->getNextWaypoint(); //third waypoint (might not exist!)
309 setLatitude(prev->latitude);
310 setLongitude(prev->longitude);
311 setSpeed(prev->speed);
312 setAltitude(prev->altitude);
313 setHeading(fp->getBearing(prev->latitude, prev->longitude, curr));
314 if (next) fp->setLeadDistance(speed, hdg, curr, next);
316 if (curr->crossat > -1000.0) { //use a calculated descent/climb rate
318 tgt_vs = (curr->crossat - prev->altitude)/
319 (fp->getDistanceToGo(pos.lat(), pos.lon(), curr)/
320 6076.0/prev->speed*60.0);
321 tgt_altitude = curr->crossat;
324 tgt_altitude = prev->altitude;
326 alt_lock = hdg_lock = true;
327 no_roll = prev->on_ground;
328 //cout << "First waypoint: " << prev->name << endl;
329 //cout << " Target speed: " << tgt_speed << endl;
330 //cout << " Target altitude: " << tgt_altitude << endl;
331 //cout << " Target heading: " << tgt_heading << endl << endl;
333 } // end of initialization
335 // let's only process the flight plan every 100 ms.
336 if (dt_count < 0.1) {
341 // check to see if we've reached the lead point for our next turn
342 double dist_to_go = fp->getDistanceToGo(pos.lat(), pos.lon(), curr);
343 double lead_dist = fp->getLeadDistance();
344 if (lead_dist < (2*speed)) lead_dist = 2*speed; //don't skip over the waypoint
345 //cout << "dist_to_go: " << dist_to_go << ", lead_dist: " << lead_dist << endl;
347 if ( dist_to_go < lead_dist ) {
348 if (curr->finished) { //end of the flight plan, so terminate
352 // we've reached the lead-point for the waypoint ahead
353 if (next) tgt_heading = fp->getBearing(curr, next);
354 fp->IncrementWaypoint();
355 prev = fp->getPreviousWaypoint();
356 curr = fp->getCurrentWaypoint();
357 next = fp->getNextWaypoint();
358 if (next) fp->setLeadDistance(speed, tgt_heading, curr, next);
359 if (curr->crossat > -1000.0) {
361 tgt_vs = (curr->crossat - altitude)/
362 (fp->getDistanceToGo(pos.lat(), pos.lon(), curr)/6076.0/speed*60.0);
363 tgt_altitude = curr->crossat;
366 tgt_altitude = prev->altitude;
368 tgt_speed = prev->speed;
369 hdg_lock = alt_lock = true;
370 no_roll = prev->on_ground;
371 //cout << "Crossing waypoint: " << prev->name << endl;
372 //cout << " Target speed: " << tgt_speed << endl;
373 //cout << " Target altitude: " << tgt_altitude << endl;
374 //cout << " Target heading: " << tgt_heading << endl << endl;
376 double calc_bearing = fp->getBearing(pos.lat(), pos.lon(), curr);
377 double hdg_error = calc_bearing - tgt_heading;
378 if (fabs(hdg_error) > 1.0) {
379 TurnTo( calc_bearing );