ProfileThrustPropulsionModel.java
/* Copyright 2002-2024 Luc Maisonobe
* 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
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.orekit.forces.maneuvers.propulsion;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.stream.Stream;
import org.hipparchus.CalculusFieldElement;
import org.hipparchus.Field;
import org.hipparchus.geometry.euclidean.threed.FieldVector3D;
import org.hipparchus.geometry.euclidean.threed.Vector3D;
import org.orekit.forces.maneuvers.Control3DVectorCostType;
import org.orekit.propagation.FieldSpacecraftState;
import org.orekit.propagation.SpacecraftState;
import org.orekit.propagation.events.DateDetector;
import org.orekit.propagation.events.EventDetector;
import org.orekit.propagation.events.FieldDateDetector;
import org.orekit.propagation.events.FieldEventDetector;
import org.orekit.time.AbsoluteDate;
import org.orekit.time.TimeStamped;
import org.orekit.utils.ParameterDriver;
import org.orekit.utils.TimeSpanMap;
/** Thrust propulsion model based on segmented profile.
* @author Luc Maisonobe
* @since 12.0
*/
public class ProfileThrustPropulsionModel implements ThrustPropulsionModel {
/** Thrust profile. */
private final TimeSpanMap<ThrustVectorProvider> profile;
/** Specific impulse. */
private final double isp;
/** Name of the maneuver. */
private final String name;
/** Type of norm linking thrust vector to mass flow rate. */
private final Control3DVectorCostType control3DVectorCostType;
/** Constructor with default cost type.
* @param profile thrust profile (N)
* @param isp specific impulse (s)
* @param name name of the maneuver
* @since 13.0
*/
public ProfileThrustPropulsionModel(final TimeSpanMap<ThrustVectorProvider> profile, final double isp,
final String name) {
this(profile, isp, Control3DVectorCostType.TWO_NORM, name);
}
/** Generic constructor.
* @param profile thrust profile (N)
* @param isp specific impulse (s)
* @param control3DVectorCostType control vector's cost type
* @param name name of the maneuver
* @since 13.0
*/
public ProfileThrustPropulsionModel(final TimeSpanMap<ThrustVectorProvider> profile, final double isp,
final Control3DVectorCostType control3DVectorCostType, final String name) {
this.name = name;
this.isp = isp;
this.profile = profile;
this.control3DVectorCostType = control3DVectorCostType;
}
/** Build with customized profile.
* @param profile thrust profile (N)
* @param isp specific impulse (s)
* @param name name of the maneuver
* @param control3DVectorCostType control vector's cost type
* @param <T> segment type
* @return propulsion model
* @since 13.0
*/
public static <T extends ThrustVectorProvider> ProfileThrustPropulsionModel of(final TimeSpanMap<T> profile,
final double isp,
final Control3DVectorCostType control3DVectorCostType,
final String name) {
return new ProfileThrustPropulsionModel(buildSegments(profile), isp, control3DVectorCostType, name);
}
/**
* Method building a map of generic segments from customized ones.
* @param timeSpanMap input profile
* @param <T> segment type
* @return generic profile
* @since 13.0
*/
private static <T extends ThrustVectorProvider> TimeSpanMap<ThrustVectorProvider> buildSegments(final TimeSpanMap<T> timeSpanMap) {
TimeSpanMap.Span<T> span = timeSpanMap.getFirstSpan();
final TimeSpanMap<ThrustVectorProvider> segments = new TimeSpanMap<>(null);
while (span != null) {
segments.addValidBetween(span.getData(), span.getStart(), span.getEnd());
span = span.next();
}
return segments;
}
/** {@inheritDoc} */
@Override
public String getName() {
return name;
}
/** {@inheritDoc} */
@Override
public Control3DVectorCostType getControl3DVectorCostType() {
return control3DVectorCostType;
}
/**
* Getter for active provider at input date.
* @param date date
* @return active segment
* @since 13.0
*/
public ThrustVectorProvider getActiveProvider(final AbsoluteDate date) {
return profile.get(date);
}
/** {@inheritDoc} */
@Override
public Vector3D getThrustVector(final SpacecraftState s) {
return getThrustVector(s, getParameters());
}
/** {@inheritDoc} */
@Override
public double getFlowRate(final SpacecraftState s) {
return getFlowRate(s, getParameters());
}
/** {@inheritDoc} */
@Override
public double getFlowRate(final SpacecraftState s, final double[] parameters) {
return -control3DVectorCostType.evaluate(getThrustVector(s, parameters)) / ThrustPropulsionModel.getExhaustVelocity(isp);
}
/** {@inheritDoc} */
@Override
public Vector3D getThrustVector(final SpacecraftState s, final double[] parameters) {
final ThrustVectorProvider active = getActiveProvider(s.getDate());
return active == null ? Vector3D.ZERO : active.getThrustVector(s.getDate(), s.getMass());
}
/** {@inheritDoc} */
public <T extends CalculusFieldElement<T>> FieldVector3D<T> getThrustVector(final FieldSpacecraftState<T> s,
final T[] parameters) {
final ThrustVectorProvider active = getActiveProvider(s.getDate().toAbsoluteDate());
return active == null ? FieldVector3D.getZero(s.getDate().getField()) :
active.getThrustVector(s.getDate(), s.getMass());
}
/** {@inheritDoc} */
public <T extends CalculusFieldElement<T>> T getFlowRate(final FieldSpacecraftState<T> s, final T[] parameters) {
return control3DVectorCostType.evaluate(getThrustVector(s, parameters)).divide(-ThrustPropulsionModel.getExhaustVelocity(isp));
}
/** {@inheritDoc}.
* <p>
* The single detector returned triggers {@link org.hipparchus.ode.events.Action#RESET_DERIVATIVES} events
* at every {@link ThrustVectorProvider} boundaries.
* </p>
*/
@Override
public Stream<EventDetector> getEventDetectors() {
final List<AbsoluteDate> transitionDates = new ArrayList<>();
for (TimeSpanMap.Transition<ThrustVectorProvider> transition = profile.getFirstTransition();
transition != null;
transition = transition.next()) {
transitionDates.add(transition.getDate());
}
final DateDetector detector = getDateDetector(transitionDates.toArray(new TimeStamped[0]));
return Stream.of(detector);
}
/** {@inheritDoc}.
* <p>
* The single detector returned triggers {@link org.hipparchus.ode.events.Action#RESET_DERIVATIVES} events
* at every {@link ThrustVectorProvider} boundaries.
* </p>
*/
@Override
public <T extends CalculusFieldElement<T>> Stream<FieldEventDetector<T>> getFieldEventDetectors(final Field<T> field) {
final List<AbsoluteDate> transitionDates = new ArrayList<>();
for (TimeSpanMap.Transition<ThrustVectorProvider> transition = profile.getFirstTransition();
transition != null;
transition = transition.next()) {
transitionDates.add(transition.getDate());
}
final FieldDateDetector<T> detector = getFieldDateDetector(field, transitionDates.toArray(new AbsoluteDate[0]));
return Stream.of(detector);
}
/** {@inheritDoc} */
@Override
public List<ParameterDriver> getParametersDrivers() {
return Collections.emptyList();
}
}