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Page créée avec « <syntaxhighlight lang="java"> public class NumericalPropagationWithUsedDV { public static void main(String[] args) throws PatriusException { Locale.s... »

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<syntaxhighlight lang="java">
public class NumericalPropagationWithUsedDV {

public static void main(String[] args) throws PatriusException {

Locale.setDefault(Locale.US);

// Patrius Dataset initialization (needed for example to get the UTC time)
PatriusDataset.addResourcesFromPatriusDataset() ;

// Recovery of the UTC time scale using a "factory" (not to duplicate such unique object)
final TimeScale TUC = TimeScalesFactory.getUTC();

// Date of the orbit given in UTC time scale)
final AbsoluteDate date0 = new AbsoluteDate("2010-01-01T12:00:00.000", TUC);

// Getting the frame with wich will defined the orbit parameters
// As for time scale, we will use also a "factory".
final Frame GCRF = FramesFactory.getGCRF();

// Initial orbit
final double sma = 7200.e+3;
final double ecc = 0.;
final double inc = FastMath.toRadians(98.);
final double pa = FastMath.toRadians(0.);
final double raan = FastMath.toRadians(0.);
final double anm = FastMath.toRadians(0.);
final double MU = Constants.WGS84_EARTH_MU;

final KeplerianParameters par = new KeplerianParameters(sma, ecc, inc, pa, raan, anm, PositionAngle.MEAN, MU);
final KeplerianOrbit iniOrbit = new KeplerianOrbit(par, GCRF, date0);

// Creating a mass model (see also specific example)
final AssemblyBuilder builder = new AssemblyBuilder();

// Main part
final double iniMass = 900.;
builder.addMainPart("MAIN");
builder.addProperty(new MassProperty(iniMass), "MAIN");

// Tank part (ergols mass)
final double ergolsMass = 100.;
final TankProperty tank = new TankProperty(ergolsMass);
builder.addPart("TANK", "MAIN", Transform.IDENTITY);
builder.addProperty(tank, "TANK");

// Engine part
final double isp = 300.;
final double thrust = 400.;
final PropulsiveProperty prop = new PropulsiveProperty(thrust, isp); // au lieu de new PropulsiveProperty("PROP", thrust, isp);

builder.addPart("PROP", "MAIN", Transform.IDENTITY);
builder.addProperty(prop, "PROP");

final Assembly assembly = builder.returnAssembly();
final MassProvider mm = new MassModel(assembly);

// We create a spacecratftstate
final SpacecraftState iniState = new SpacecraftState(iniOrbit, mm);

// Initialization of the Runge Kutta integrator with a 2 s step
final double pasRk = 2.;
final FirstOrderIntegrator integrator = new ClassicalRungeKuttaIntegrator(pasRk);

// Initialization of the propagator
final NumericalPropagator propagator = new NumericalPropagator(integrator);
propagator.resetInitialState(iniState);

// Forcing integration using cartesian equations
propagator.setOrbitType(OrbitType.CARTESIAN);

final ArrayList<DateDetector> listOfEvents = new ArrayList<DateDetector>();

// Event corresponding to the criteria to trigger the impulsive maneuver
final DateDetector eventImp = new DateDetector(date0.shiftedBy(10.));
listOfEvents.add(eventImp);
// Creation of the impulsive maneuver
final double dv = 20.;
final Vector3D deltaV = new Vector3D(dv, 0., 0.);
final ImpulseManeuver imp = new ImpulseManeuver(eventImp, deltaV, prop, mm, tank, LOFType.TNW);

// Duration of the maneuver to reach the initial semi major axis
final double duration = 49.4933;
System.out.println(duration);
// Creation of the continuous thrust maneuver
final AbsoluteDate startDate = date0.shiftedBy(iniOrbit.getKeplerianPeriod()-0.5*duration);
final DateDetector eventStart = new DateDetector(startDate);
final DateDetector eventEnd = new DateDetector(startDate.shiftedBy(duration));
listOfEvents.add(eventStart);
listOfEvents.add(eventEnd);
final Vector3D direction = new Vector3D(-1., 0., 0.);
final ContinuousThrustManeuver man = new ContinuousThrustManeuver(eventStart, eventEnd, prop, direction, mm, tank);

// Creation of the sequence of maneuver
ManeuversSequence seq = new ManeuversSequence(0., 0.);
seq.add(imp);
seq.add(man);

// Adding the maneuver sequence to the propagator
seq.applyTo(propagator);
// Adding additional state
propagator.setMassProviderEquation(mm);

// Adding an attitude law (or attitude sequence : mandatory)
final AttitudeLaw attitudeLaw = new LofOffset(LOFType.TNW, RotationOrder.ZYX, 0., 0., 0.);
propagator.setAttitudeProvider(attitudeLaw);

// Dt to get information just before/after an event
final double dt = 1.e-6;

for (int i = 0; i < listOfEvents.size(); i++) {

System.out.println("\nEVENT #"+i);

System.out.println("Before ...");
final AbsoluteDate dateBefore = listOfEvents.get(i).getDate().shiftedBy(-dt);
final SpacecraftState finalStateBefore = propagator.propagate(dateBefore);
printResults(dateBefore.toString(TUC), finalStateBefore, imp, man);

System.out.println("After ...");
final AbsoluteDate dateAfter = listOfEvents.get(i).getDate().shiftedBy(dt);
final SpacecraftState finalStateAfter = propagator.propagate(dateAfter);
printResults(dateAfter.toString(TUC), finalStateAfter, imp, man);
}

}

private static void printResults ( final String sdate, final SpacecraftState sc,
final ImpulseManeuver imp, final ContinuousThrustManeuver man ) throws PatriusException {
System.out.println(" Date = "+sdate);
System.out.println(" Impulsive Maneuver = "+imp.getUsedDV()+" m/s");
System.out.println(" Continuous Maneuver = "+man.getUsedDV()+" m/s");
System.out.println(" Ergols Mass = "+sc.getMass("TANK")+" kg");
System.out.println(" Semi major axis = "+sc.getA()/1000.+" km");
System.out.println(" Eccentricity = "+sc.getE());
}

}
</syntaxhighlight>

NumericalPropagationWithUsedDV 4.5.1 - Historique des versions

Admin : Page créée avec « public class NumericalPropagationWithUsedDV { public static void main(String[] args) throws PatriusException { Locale.s... »

Admin : Page créée avec « public class NumericalPropagationWithUsedDV { public static void main(String[] args) throws PatriusException { Locale.s... »