#include "AIBallistic.hxx"
-FGAIBallistic::FGAIBallistic(FGAIManager* mgr) {
- manager = mgr;
- _type_str = "ballistic";
- _otype = otBallistic;
+FGAIBallistic::FGAIBallistic() : FGAIBase(otBallistic) {
drag_area = 0.007;
life_timer = 0.0;
+ gravity = 32;
+// buoyancy = 64;
+ no_roll = false;
+ aero_stabilised = false;
}
FGAIBallistic::~FGAIBallistic() {
}
+void FGAIBallistic::readFromScenario(SGPropertyNode* scFileNode) {
+ if (!scFileNode)
+ return;
+
+ FGAIBase::readFromScenario(scFileNode);
+
+ setAzimuth(scFileNode->getDoubleValue("azimuth", 0.0));
+ setElevation(scFileNode->getDoubleValue("elevation", 0.0));
+ setDragArea(scFileNode->getDoubleValue("eda", 0.007));
+ setLife(scFileNode->getDoubleValue("life", 900.0));
+ setBuoyancy(scFileNode->getDoubleValue("buoyancy", 0));
+ setWind_from_east(scFileNode->getDoubleValue("wind_from_east", 0));
+ setWind_from_north(scFileNode->getDoubleValue("wind_from_north", 0));
+ setWind(scFileNode->getBoolValue("wind", false));
+ setRoll(scFileNode->getDoubleValue("roll", 0.0));
+ setCd(scFileNode->getDoubleValue("cd", 0.029));
+ setMass(scFileNode->getDoubleValue("mass", 0.007));
+ setStabilisation(scFileNode->getBoolValue("aero_stabilized", false));
+}
bool FGAIBallistic::init() {
FGAIBase::init();
- aero_stabilized = true;
hdg = azimuth;
pitch = elevation;
+ roll = rotation;
+ Transform();
return true;
}
void FGAIBallistic::bind() {
// FGAIBase::bind();
+ props->tie("sim/time/elapsed-sec",
+ SGRawValueMethods<FGAIBallistic,double>(*this,
+ &FGAIBallistic::_getTime));
}
void FGAIBallistic::unbind() {
// FGAIBase::unbind();
+ props->untie("sim/time/elapsed-sec");
}
void FGAIBallistic::update(double dt) {
pitch = elevation = el;
}
+void FGAIBallistic::setRoll(double rl) {
+ rotation = rl;
+}
-void FGAIBallistic::setStabilization(bool val) {
- aero_stabilized = val;
+void FGAIBallistic::setStabilisation(bool val) {
+ aero_stabilised = val;
}
void FGAIBallistic::setDragArea(double a) {
life = seconds;
}
+void FGAIBallistic::setBuoyancy(double fpss) {
+ buoyancy = fpss;
+}
+
+void FGAIBallistic::setWind_from_east(double fps) {
+ wind_from_east = fps;
+}
+
+void FGAIBallistic::setWind_from_north(double fps) {
+ wind_from_north = fps;
+}
+
+void FGAIBallistic::setWind(bool val) {
+ wind = val;
+}
+
+void FGAIBallistic::setCd(double c) {
+ Cd = c;
+}
+
+void FGAIBallistic::setMass(double m) {
+ mass = m;
+}
+
void FGAIBallistic::Run(double dt) {
life_timer += dt;
+// cout << "life timer 1" << life_timer << dt << endl;
if (life_timer > life) setDie(true);
double speed_north_deg_sec;
double speed_east_deg_sec;
-
- // the two drag calculations below assume sea-level density,
- // mass of 0.03 slugs, drag coeff of 0.295
- // adjust speed due to drag
- speed -= 0.0116918 * drag_area * speed * speed * dt;
+ double wind_speed_from_north_deg_sec;
+ double wind_speed_from_east_deg_sec;
+ double Cdm; // Cd adjusted by Mach Number
+
+ // Adjust Cd by Mach number. The equations are based on curves
+ // for a conventional shell/bullet (no boat-tail).
+ if ( Mach < 0.7 ) { Cdm = 0.0125 * Mach + Cd; }
+ else if ( 0.7 < Mach && Mach < 1.2 ) {
+ Cdm = 0.3742 * pow ( Mach, 2) - 0.252 * Mach + 0.0021 + Cd; }
+ else { Cdm = 0.2965 * pow ( Mach, -1.1506 ) + Cd; }
+
+// cout << " Mach , " << Mach << " , Cdm , " << Cdm << endl;
+
+ // drag = Cd * 0.5 * rho * speed * speed * drag_area;
+ // rho is adjusted for altitude in void FGAIBase::update,
+ // using Standard Atmosphere (sealevel temperature 15C)
+ // acceleration = drag/mass;
+ // adjust speed by drag
+ speed -= (Cdm * 0.5 * rho * speed * speed * drag_area/mass) * dt;
+
+ // don't let speed become negative
if ( speed < 0.0 ) speed = 0.0;
+
+ // calculate vertical and horizontal speed components
vs = sin( pitch * SG_DEGREES_TO_RADIANS ) * speed;
hs = cos( pitch * SG_DEGREES_TO_RADIANS ) * speed;
// convert horizontal speed (fps) to degrees per second
speed_north_deg_sec = cos(hdg / SG_RADIANS_TO_DEGREES) * hs / ft_per_deg_lat;
speed_east_deg_sec = sin(hdg / SG_RADIANS_TO_DEGREES) * hs / ft_per_deg_lon;
-
+
+ // if wind not required, set to zero
+ if (!wind) {
+ wind_from_north = 0;
+ wind_from_east = 0;
+ }
+
+ // convert wind speed (fps) to degrees per second
+ wind_speed_from_north_deg_sec = wind_from_north / ft_per_deg_lat;
+ wind_speed_from_east_deg_sec = wind_from_east / ft_per_deg_lon;
+
// set new position
- pos.setlat( pos.lat() + speed_north_deg_sec * dt);
- pos.setlon( pos.lon() + speed_east_deg_sec * dt);
+ pos.setlat( pos.lat() + (speed_north_deg_sec - wind_speed_from_north_deg_sec) * dt );
+ pos.setlon( pos.lon() + (speed_east_deg_sec - wind_speed_from_east_deg_sec) * dt );
+ // adjust vertical speed for acceleration of gravity and buoyancy
+ vs -= (gravity - buoyancy) * dt;
+
// adjust altitude (feet)
altitude += vs * dt;
pos.setelev(altitude * SG_FEET_TO_METER);
- // adjust vertical speed for acceleration of gravity
- vs -= 32.17 * dt;
-
// recalculate pitch (velocity vector) if aerostabilized
- if (aero_stabilized) pitch = atan2( vs, hs ) * SG_RADIANS_TO_DEGREES;
+ // cout << "aero_stabilised " << aero_stabilised << endl ;
+ if (aero_stabilised) pitch = atan2( vs, hs ) * SG_RADIANS_TO_DEGREES;
// recalculate total speed
speed = sqrt( vs * vs + hs * hs);
// set destruction flag if altitude less than sea level -1000
if (altitude < -1000.0) setDie(true);
+} // end Run
+
+double FGAIBallistic::_getTime() const {
+// cout << "life timer 2" << life_timer << endl;
+ return life_timer;
}
+// end AIBallistic
projects / flightgear.git / blobdiff