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Change the start of descent point of the AI plane when the circuit has been extended when following previous traffic - it should not land short now, although it can land a way down the runway if start of descent should occur during a turn, since it doesnt start descending until the turn is finished

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daveluff 2003-09-05 10:26:11 +00:00
parent be274df23b
commit b898c5e4ff
2 changed files with 103 additions and 17 deletions
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108
src/ATC/AILocalTraffic.cxx
View file

@ -82,6 +82,9 @@ FGAILocalTraffic::FGAILocalTraffic() {
reportReadyForDeparture = false;
contactTower = false;
contactGround = false;
descending = false;
targetDescentRate = 0.0;
}
FGAILocalTraffic::~FGAILocalTraffic() {
@ -540,6 +543,11 @@ void FGAILocalTraffic::Update(double dt) {
break;
}
//cout << "I " << flush;
// Convienience output for AI debugging user the property logger
fgSetDouble("/AI/Local1/ortho-x", (ortho.ConvertToLocal(pos)).x());
fgSetDouble("/AI/Local1/ortho-y", (ortho.ConvertToLocal(pos)).y());
fgSetDouble("/AI/Local1/elev", pos.elev() * SG_METER_TO_FEET);
}
void FGAILocalTraffic::RegisterTransmission(int code) {
@ -619,7 +627,8 @@ void FGAILocalTraffic::FlyTrafficPattern(double dt) {
leg = CLIMBOUT;
pitch = 10.0;
IAS = best_rate_of_climb_speed;
slope = 7.0;
//slope = 7.0;
slope = 6.0; // Reduced it slightly since it's climbing a lot steeper than I can in the JSBSim C172.
inAir = true;
}
break;
@ -704,15 +713,32 @@ void FGAILocalTraffic::FlyTrafficPattern(double dt) {
TransmitPatternPositionReport();
transmitted = true;
}
if(orthopos.y() < -480) {
// FIXME - TODO - take tower baseleg constraint ie. other traffic, into account when calculating start of descent
slope = -4.0; // FIXME - calculate to descent at 500fpm and hit the threshold (taking wind into account as well!!)
if((orthopos.y() < -100) && (!descending)) {
// Maybe we should think about when to start descending.
// For now we're assuming that we aim to follow the same glidepath regardless of wind.
double d1;
double d2;
CalculateSoD((tower->GetBaseConstraint(d1) ? d1 : -1000.0), (tower->GetDownwindConstraint(d2) ? d2 : 1000.0 * patternDirection), (patternDirection ? true : false));
if(SoD.leg == DOWNWIND) {
descending = (orthopos.y() < SoD.y ? true : false);
}
}
if(descending) {
slope = -5.5; // FIXME - calculate to descent at 500fpm and hit the desired point on the runway (taking wind into account as well!!)
pitch = -3.0;
IAS = 85.0;
}
if(orthopos.y() < -980) {
// Try and arrange to turn nicely onto base
turn_circumference = IAS * 0.514444 * turn_time;
//Hmmm - this is an interesting one - ground vs airspeed in relation to turn radius
//We'll leave it as a hack with IAS for now but it needs revisiting.
turn_radius = turn_circumference / (2.0 * DCL_PI);
if(orthopos.y() < -1000.0 + turn_radius) {
//if(orthopos.y() < -980) {
double bb = 0.0;
if(tower->GetDownwindConstraint(bb)) {
if(tower->GetBaseConstraint(bb)) {
if(fabs(orthopos.y()) > fabs(bb)) {
cout << "Turning to base, distance from threshold = " << fabs(orthopos.y()) << '\n';
leg = TURN3;
@ -740,15 +766,29 @@ void FGAILocalTraffic::FlyTrafficPattern(double dt) {
TransmitPatternPositionReport();
transmitted = true;
}
if(!descending) {
double d1;
// Make downwind leg position artifically large to avoid any chance of SoD being returned as
// on downwind when we are already on base.
CalculateSoD((tower->GetBaseConstraint(d1) ? d1 : -1000.0), (10000.0 * patternDirection), (patternDirection ? true : false));
if(SoD.leg == BASE) {
descending = (fabs(orthopos.y()) < fabs(SoD.y) ? true : false);
}
}
if(descending) {
slope = -5.5; // FIXME - calculate to descent at 500fpm and hit the threshold (taking wind into account as well!!)
pitch = -4.0;
IAS = 70.0;
}
track = rwy.hdg - (90 * patternDirection);
slope = -6.0; // FIXME - calculate to descent at 500fpm and hit the threshold
pitch = -4.0;
IAS = 70.0; // FIXME - slowdown gradually
// Try and arrange to turn nicely onto base
// Try and arrange to turn nicely onto final
turn_circumference = IAS * 0.514444 * turn_time;
//Hmmm - this is an interesting one - ground vs airspeed in relation to turn radius
//We'll leave it as a hack with IAS for now but it needs revisiting.
//We'll leave it as a hack with IAS for now but it needs revisiting.
turn_radius = turn_circumference / (2.0 * DCL_PI);
if(fabs(orthopos.x()) < (turn_radius + 50)) {
leg = TURN4;
@ -770,6 +810,20 @@ void FGAILocalTraffic::FlyTrafficPattern(double dt) {
TransmitPatternPositionReport();
transmitted = true;
}
if(!descending) {
// Make base leg position artifically large to avoid any chance of SoD being returned as
// on base or downwind when we are already on final.
CalculateSoD(-10000.0, (1000.0 * patternDirection), (patternDirection ? true : false));
if(SoD.leg == FINAL) {
descending = (fabs(orthopos.y()) < fabs(SoD.y) ? true : false);
}
}
if(descending) {
slope = -5.5; // FIXME - calculate to descent at 500fpm and hit the threshold (taking wind into account as well!!)
pitch = -4.0;
IAS = 70.0;
}
// Try and track the extended centreline
track = rwy.hdg - (0.2 * orthopos.x());
//cout << "orthopos.x() = " << orthopos.x() << " hdg = " << hdg << '\n';
@ -861,6 +915,36 @@ void FGAILocalTraffic::FlyTrafficPattern(double dt) {
pos = dclUpdatePosition(pos, track, slope, dist);
}
// Pattern direction is true for right, false for left
void FGAILocalTraffic::CalculateSoD(double base_leg_pos, double downwind_leg_pos, bool pattern_direction) {
// For now we'll ignore wind and hardwire the glide angle.
double ga = 5.5; //degrees
double pa = 1000.0 * SG_FEET_TO_METER; // pattern altitude in meters
// FIXME - get glideslope angle and pattern altitude agl from airport details if available
// For convienience, we'll have +ve versions of the input distances
double blp = fabs(base_leg_pos);
double dlp = fabs(downwind_leg_pos);
//double turn_allowance = 150.0; // Approximate distance in meters that a 90deg corner is shortened by turned in a light plane.
double stod = pa / tan(ga * DCL_DEGREES_TO_RADIANS); // distance in meters from touchdown point to start descent
cout << "Descent to start = " << stod << " meters out\n";
if(stod < blp) { // Start descending on final
SoD.leg = FINAL;
SoD.y = stod * -1.0;
SoD.x = 0.0;
} else if(stod < (blp + dlp)) { // Start descending on base leg
SoD.leg = BASE;
SoD.y = blp * -1.0;
SoD.x = (pattern_direction ? (stod - dlp) : (stod - dlp) * -1.0);
} else { // Start descending on downwind leg
SoD.leg = DOWNWIND;
SoD.x = (pattern_direction ? dlp : dlp * -1.0);
SoD.y = (blp - (stod - (blp + dlp))) * -1.0;
}
}
void FGAILocalTraffic::TransmitPatternPositionReport(void) {
// airport name + "traffic" + airplane callsign + pattern direction + pattern leg + rwy + ?
string trns = "";

12
src/ATC/AILocalTraffic.hxx
View file

@ -48,10 +48,10 @@ enum OperatingState {
PARKED
};
struct StartofDescent {
struct StartOfDescent {
PatternLeg leg;
double orthopos_x;
double orthopos_y;
double x; // Runway aligned orthopos
double y; // ditto
};
class FGAILocalTraffic : public FGAIPlane {
@ -143,7 +143,9 @@ private:
int numAhead; // More importantly - how many of them are ahead of us?
double distToNext; // And even more importantly, how near are we getting to the one immediately ahead?
//PatternLeg leg; // Our current position in the pattern - now moved to FGAIPlane
StartofDescent SoD; // Start of descent calculated wrt wind, pattern size & altitude, glideslope etc
StartOfDescent SoD; // Start of descent calculated wrt wind, pattern size & altitude, glideslope etc
bool descending; // We're in the coming down phase of the pattern
double targetDescentRate; // m/s
// Taxiing details
// At the moment this assumes that all taxiing in is to gates (a loose term that includes
@ -179,7 +181,7 @@ private:
void TransmitPatternPositionReport();
void CalculateStartofDescent();
void CalculateSoD(double base_leg_pos, double downwind_leg_pos, bool pattern_direction);
void ExitRunway(Point3D orthopos);