FieldImpulseManeuver.java
/* Copyright 2002-2024 Exotrail
* Licensed to CS GROUP (CS) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* CS licenses this file to You under the Apache License, Version 2.0
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*
* http://www.apache.org/licenses/LICENSE-2.0
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* Unless required by applicable law or agreed to in writing, software
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package org.orekit.forces.maneuvers;
import org.hipparchus.CalculusFieldElement;
import org.hipparchus.geometry.euclidean.threed.FieldRotation;
import org.hipparchus.geometry.euclidean.threed.FieldVector3D;
import org.hipparchus.ode.events.Action;
import org.hipparchus.util.FastMath;
import org.orekit.attitudes.AttitudeProvider;
import org.orekit.orbits.FieldCartesianOrbit;
import org.orekit.orbits.FieldOrbit;
import org.orekit.propagation.FieldSpacecraftState;
import org.orekit.propagation.events.FieldDetectorModifier;
import org.orekit.propagation.events.FieldEventDetectionSettings;
import org.orekit.propagation.events.FieldEventDetector;
import org.orekit.propagation.events.handlers.FieldEventHandler;
import org.orekit.time.FieldAbsoluteDate;
import org.orekit.utils.Constants;
import org.orekit.utils.FieldArrayDictionary;
import org.orekit.utils.FieldPVCoordinates;
/** Impulse maneuver model for propagators working with Fields.
* <p>This class implements an impulse maneuver as a discrete event
* that can be provided to any {@link org.orekit.propagation.FieldPropagator
* Propagator} and mirrors the standard version
* {@link org.orekit.forces.maneuvers.ImpulseManeuver}.</p>
* <p>The maneuver is executed when an underlying is triggered, in which case this class will generate a {@link
* Action#RESET_STATE RESET_STATE} event. By default, the detection settings are those of the trigger.
* In the simple cases, the underlying event detector may be a basic
* {@link org.orekit.propagation.events.FieldDateDetector date event}, but it
* can also be a more elaborate {@link
* org.orekit.propagation.events.FieldApsideDetector apside event} for apogee
* maneuvers for example.</p>
* <p>The maneuver velocity increment is defined via {@link FieldImpulseProvider}.
* If no AttitudeProvider is given, the current attitude of the spacecraft,
* defined by the current spacecraft state, will be used as the
* {@link AttitudeProvider} so the velocity increment should be given in
* the same pseudoinertial frame as the {@link FieldSpacecraftState} used to
* construct the propagator that will handle the maneuver.
* If an AttitudeProvider is given, the velocity increment given should be
* defined appropriately in consideration of that provider. So, a typical
* case for tangential maneuvers is to provide a {@link org.orekit.attitudes.LofOffset LOF aligned}
* attitude provider along with a velocity increment defined in accordance with
* that LOF aligned attitude provider; e.g. if the LOF aligned attitude provider
* was constructed using LOFType.VNC the velocity increment should be
* provided in VNC coordinates.</p>
* <p>The norm through which the delta-V maps to the mass consumption is chosen via the
* enum {@link Control3DVectorCostType}. Default is Euclidean. </p>
* <p>Beware that the triggering event detector must behave properly both
* before and after maneuver. If for example a node detector is used to trigger
* an inclination maneuver and the maneuver change the orbit to an equatorial one,
* the node detector will fail just after the maneuver, being unable to find a
* node on an equatorial orbit! This is a real case that has been encountered
* during validation ...</p>
* @see org.orekit.propagation.FieldPropagator#addEventDetector(FieldEventDetector)
* @see org.orekit.forces.maneuvers.ImpulseManeuver
* @author Romain Serra
* @since 12.0
* @param <T> type of the field elements
*/
public class FieldImpulseManeuver<T extends CalculusFieldElement<T>> extends AbstractImpulseManeuver
implements FieldDetectorModifier<T> {
/** Triggering event. */
private final FieldEventDetector<T> trigger;
/** Specific impulse. */
private final T isp;
/** Engine exhaust velocity. */
private final T vExhaust;
/** Trigger's detection settings. */
private final FieldEventDetectionSettings<T> detectionSettings;
/** Specific event handler. */
private final Handler<T> handler;
/** Field impulse provider. */
private final FieldImpulseProvider<T> fieldImpulseProvider;
/** Indicator for forward propagation. */
private boolean forward;
/** Build a new instance.
* @param trigger triggering event
* @param deltaVSat velocity increment in satellite frame
* @param isp engine specific impulse (s)
*/
public FieldImpulseManeuver(final FieldEventDetector<T> trigger, final FieldVector3D<T> deltaVSat, final T isp) {
this(trigger, null, deltaVSat, isp);
}
/** Build a new instance.
* @param trigger triggering event
* @param attitudeOverride the attitude provider to use for the maneuver
* @param deltaVSat velocity increment in satellite frame
* @param isp engine specific impulse (s)
*/
public FieldImpulseManeuver(final FieldEventDetector<T> trigger, final AttitudeProvider attitudeOverride,
final FieldVector3D<T> deltaVSat, final T isp) {
this(trigger, attitudeOverride, FieldImpulseProvider.of(deltaVSat), isp, Control3DVectorCostType.TWO_NORM);
}
/** Build a new instance.
* @param trigger triggering event
* @param attitudeOverride the attitude provider to use for the maneuver
* @param deltaVSat velocity increment in satellite frame
* @param isp engine specific impulse (s)
* @param control3DVectorCostType increment's norm for mass consumption
* @deprecated since 13.0
*/
@Deprecated
public FieldImpulseManeuver(final FieldEventDetector<T> trigger, final AttitudeProvider attitudeOverride,
final FieldVector3D<T> deltaVSat, final T isp,
final Control3DVectorCostType control3DVectorCostType) {
this(trigger, trigger.getDetectionSettings(), attitudeOverride,
FieldImpulseProvider.of(deltaVSat), isp, control3DVectorCostType);
}
/** Build a new instance.
* @param trigger triggering event
* @param attitudeOverride the attitude provider to use for the maneuver
* @param fieldImpulseProvider impulse provider
* @param isp engine specific impulse (s)
* @param control3DVectorCostType increment's norm for mass consumption
*/
public FieldImpulseManeuver(final FieldEventDetector<T> trigger, final AttitudeProvider attitudeOverride,
final FieldImpulseProvider<T> fieldImpulseProvider, final T isp,
final Control3DVectorCostType control3DVectorCostType) {
this(trigger, trigger.getDetectionSettings(), attitudeOverride, fieldImpulseProvider, isp, control3DVectorCostType);
}
/** Private constructor.
* @param trigger triggering event
* @param detectionSettings event detection settings
* @param attitudeOverride the attitude provider to use for the maneuver
* @param fieldImpulseProvider impulse provider
* @param isp engine specific impulse (s)
* @param control3DVectorCostType increment's norm for mass consumption
*/
private FieldImpulseManeuver(final FieldEventDetector<T> trigger,
final FieldEventDetectionSettings<T> detectionSettings,
final AttitudeProvider attitudeOverride, final FieldImpulseProvider<T> fieldImpulseProvider,
final T isp, final Control3DVectorCostType control3DVectorCostType) {
super(attitudeOverride, control3DVectorCostType);
this.trigger = trigger;
this.detectionSettings = detectionSettings;
this.fieldImpulseProvider = fieldImpulseProvider;
this.isp = isp;
this.vExhaust = this.isp.multiply(Constants.G0_STANDARD_GRAVITY);
this.handler = new Handler<>();
}
/**
* Creates a copy with different event detection settings.
* @param eventDetectionSettings new detection settings
* @return a new detector with same properties except for the detection settings
*/
public FieldImpulseManeuver<T> withDetectionSettings(final FieldEventDetectionSettings<T> eventDetectionSettings) {
return new FieldImpulseManeuver<>(trigger, eventDetectionSettings, getAttitudeOverride(), fieldImpulseProvider, isp,
getControl3DVectorCostType());
}
/** {@inheritDoc} */
@Override
public void init(final FieldSpacecraftState<T> s0, final FieldAbsoluteDate<T> t) {
FieldDetectorModifier.super.init(s0, t);
forward = t.durationFrom(s0.getDate()).getReal() >= 0;
}
/** {@inheritDoc} */
@Override
public FieldEventDetectionSettings<T> getDetectionSettings() {
return detectionSettings;
}
/** {@inheritDoc} */
@Override
public FieldEventDetector<T> getDetector() {
return trigger;
}
/** Get the triggering event.
* @return triggering event
*/
public FieldEventDetector<T> getTrigger() {
return getDetector();
}
/**
* Getter for the impulse provider.
* @return impulse provider
* @since 13.0
*/
public FieldImpulseProvider<T> getFieldImpulseProvider() {
return fieldImpulseProvider;
}
/** Get the specific impulse.
* @return specific impulse
*/
public T getIsp() {
return isp;
}
@Override
public FieldEventHandler<T> getHandler() {
return handler;
}
/** Local handler. */
private static class Handler<T extends CalculusFieldElement<T>> implements FieldEventHandler<T> {
/** {@inheritDoc} */
@Override
public Action eventOccurred(final FieldSpacecraftState<T> s,
final FieldEventDetector<T> detector,
final boolean increasing) {
final FieldImpulseManeuver<T> im = (FieldImpulseManeuver<T>) detector;
im.trigger.getHandler().eventOccurred(s, detector, increasing); // Action ignored but method still called
return Action.RESET_STATE;
}
/** {@inheritDoc} */
@Override
public FieldSpacecraftState<T> resetState(final FieldEventDetector<T> detector,
final FieldSpacecraftState<T> oldState) {
final FieldImpulseManeuver<T> im = (FieldImpulseManeuver<T>) detector;
final FieldAbsoluteDate<T> date = oldState.getDate();
final boolean isStateOrbitDefined = oldState.isOrbitDefined();
final FieldRotation<T> rotation;
if (im.getAttitudeOverride() == null) {
rotation = oldState.getAttitude().getRotation();
} else {
rotation = im.getAttitudeOverride().getAttitudeRotation(isStateOrbitDefined ? oldState.getOrbit() : oldState.getAbsPVA(),
date, oldState.getFrame());
}
// convert velocity increment in inertial frame
final FieldVector3D<T> deltaVSat = im.fieldImpulseProvider.getImpulse(oldState, im.forward, im.getAttitudeOverride());
final FieldVector3D<T> deltaV = rotation.applyInverseTo(deltaVSat);
final T one = oldState.getMu().getField().getOne();
final T sign = (im.forward) ? one : one.negate();
// apply increment to position/velocity
final FieldPVCoordinates<T> oldPV = oldState.getPVCoordinates();
final FieldVector3D<T> newVelocity = oldPV.getVelocity().add(deltaV);
final FieldPVCoordinates<T> newPV = new FieldPVCoordinates<>(oldPV.getPosition(), newVelocity);
final FieldOrbit<T> newOrbit = new FieldCartesianOrbit<>(newPV, oldState.getFrame(), date, oldState.getMu());
// compute new mass
final T normDeltaV = im.getControl3DVectorCostType().evaluate(deltaVSat);
final T newMass = oldState.getMass().multiply(FastMath.exp(normDeltaV.multiply(sign.negate()).divide(im.vExhaust)));
// pack everything in a new state
FieldSpacecraftState<T> newState;
if (isStateOrbitDefined) {
newState = new FieldSpacecraftState<>(oldState.getOrbit().getType().normalize(newOrbit,
oldState.getOrbit()), oldState.getAttitude(), newMass);
} else {
newState = new FieldSpacecraftState<>(oldState.getAbsPVA(), oldState.getAttitude(), newMass);
}
for (final FieldArrayDictionary<T>.Entry entry : oldState.getAdditionalStatesValues().getData()) {
newState = newState.addAdditionalState(entry.getKey(), entry.getValue());
}
for (final FieldArrayDictionary<T>.Entry entry : oldState.getAdditionalStatesDerivatives().getData()) {
newState = newState.addAdditionalStateDerivative(entry.getKey(), entry.getValue());
}
return newState;
}
}
}