ConstantThrustManeuver.java
/* Copyright 2002-2022 CS GROUP
* 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;
import org.hipparchus.CalculusFieldElement;
import org.hipparchus.geometry.euclidean.threed.Vector3D;
import org.orekit.attitudes.AttitudeProvider;
import org.orekit.forces.maneuvers.propulsion.AbstractConstantThrustPropulsionModel;
import org.orekit.forces.maneuvers.propulsion.BasicConstantThrustPropulsionModel;
import org.orekit.forces.maneuvers.trigger.DateBasedManeuverTriggers;
import org.orekit.propagation.FieldSpacecraftState;
import org.orekit.propagation.SpacecraftState;
import org.orekit.time.AbsoluteDate;
/** This class implements a simple maneuver with constant thrust.
* <p>The maneuver is defined by a direction in satellite frame.
* The current attitude of the spacecraft, defined by the current
* spacecraft state, will be used to compute the thrust direction in
* inertial frame. A typical case for tangential maneuvers is to use a
* {@link org.orekit.attitudes.LofOffset LOF aligned} attitude provider
* for state propagation and a velocity increment along the +X satellite axis.</p>
* @author Fabien Maussion
* @author Véronique Pommier-Maurussane
* @author Luc Maisonobe
* @author Maxime Journot
*/
public class ConstantThrustManeuver extends Maneuver {
/** Simple constructor for a constant direction and constant thrust.
* <p>
* It uses the propulsion model {@link BasicConstantThrustPropulsionModel} and
* the maneuver triggers {@link DateBasedManeuverTriggers}
* </p><p>
* Calling this constructor is equivalent to call {@link
* #ConstantThrustManeuver(AbsoluteDate, double, double, double, Vector3D, String)
* ConstantThrustManeuver(date, duration, thrust, isp, direction, "")},
* hence not using any prefix for the parameters drivers names.
* </p>
* @param date maneuver date
* @param duration the duration of the thrust (s) (if negative,
* the date is considered to be the stop date)
* @param thrust the thrust force (N)
* @param isp engine specific impulse (s)
* @param direction the acceleration direction in satellite frame.
*/
public ConstantThrustManeuver(final AbsoluteDate date, final double duration,
final double thrust, final double isp,
final Vector3D direction) {
this(date, duration, thrust, isp, direction, "");
}
/** Simple constructor for a constant direction and constant thrust.
* <p>
* It uses the propulsion model {@link BasicConstantThrustPropulsionModel} and
* the maneuver triggers {@link DateBasedManeuverTriggers}
* </p><p>
* Calling this constructor is equivalent to call {@link
* #ConstantThrustManeuver(AbsoluteDate, double, double, double, Vector3D, String)
* ConstantThrustManeuver(date, duration, thrust, isp, direction, "")},
* hence not using any prefix for the parameters drivers names.
* </p>
* @param date maneuver date
* @param duration the duration of the thrust (s) (if negative,
* the date is considered to be the stop date)
* @param thrust the thrust force (N)
* @param isp engine specific impulse (s)
* @param attitudeOverride the attitude provider to use for the maneuver, or
* null if the attitude from the propagator should be used
* @param direction the acceleration direction in satellite frame.
* @since 9.2
*/
public ConstantThrustManeuver(final AbsoluteDate date, final double duration,
final double thrust, final double isp,
final AttitudeProvider attitudeOverride, final Vector3D direction) {
this(date, duration, thrust, isp, attitudeOverride, direction, "");
}
/** Simple constructor for a constant direction and constant thrust.
* <p>
* It uses the propulsion model {@link BasicConstantThrustPropulsionModel} and
* the maneuver triggers {@link DateBasedManeuverTriggers}
* </p><p>
* The name of the maneuver is used to distinguish the parameter drivers.
* A typical use case is to use something like "1A-" or "2B-" as a prefix corresponding to the
* name of the thruster to use, so separate parameters can be adjusted
* for the different thrusters involved during an orbit determination
* where maneuvers parameters are estimated.
* </p>
* @param date maneuver date
* @param duration the duration of the thrust (s) (if negative,
* the date is considered to be the stop date)
* @param thrust the thrust force (N)
* @param isp engine specific impulse (s)
* @param direction the acceleration direction in satellite frame
* @param name name of the maneuver, used as a prefix for the {@link #getParametersDrivers() parameters drivers}
* @since 9.0
*/
public ConstantThrustManeuver(final AbsoluteDate date, final double duration,
final double thrust, final double isp,
final Vector3D direction,
final String name) {
this(date, duration, thrust, isp, null, direction, name);
}
/** Simple constructor for a constant direction and constant thrust.
* <p>
* It uses the propulsion model {@link BasicConstantThrustPropulsionModel} and
* the maneuver triggers {@link DateBasedManeuverTriggers}
* </p><p>
* The name of the maneuver is used to distinguish the parameter drivers.
* A typical use case is to use something like "1A-" or "2B-" as a prefix corresponding to the
* name of the thruster to use, so separate parameters can be adjusted
* for the different thrusters involved during an orbit determination
* where maneuvers parameters are estimated.
* </p>
* @param date maneuver date
* @param duration the duration of the thrust (s) (if negative,
* the date is considered to be the stop date)
* @param thrust the thrust force (N)
* @param isp engine specific impulse (s)
* @param attitudeOverride the attitude provider to use for the maneuver, or
* null if the attitude from the propagator should be used
* @param direction the acceleration direction in satellite frame
* @param name name of the maneuver, used as a prefix for the {@link #getParametersDrivers() parameters drivers}
* @since 9.2
*/
public ConstantThrustManeuver(final AbsoluteDate date, final double duration,
final double thrust, final double isp,
final AttitudeProvider attitudeOverride, final Vector3D direction,
final String name) {
this(date, duration, attitudeOverride, new BasicConstantThrustPropulsionModel(thrust, isp, direction, name));
}
/** Simple constructor for a constant direction and constant thrust.
* <p>
* It uses an {@link AbstractConstantThrustPropulsionModel} and
* the maneuver triggers {@link DateBasedManeuverTriggers}
* </p><p>
* The names of the maneuver (and thus its parameter drivers) are extracted
* from the propulsion model.
* </p>
* @param date maneuver date
* @param duration the duration of the thrust (s) (if negative,
* the date is considered to be the stop date)
* @param attitudeOverride the attitude provider to use for the maneuver, or
* null if the attitude from the propagator should be used
* @param constantThrustPropulsionModel user-defined constant thrust propulsion model
*/
public ConstantThrustManeuver(final AbsoluteDate date, final double duration,
final AttitudeProvider attitudeOverride,
final AbstractConstantThrustPropulsionModel constantThrustPropulsionModel) {
this(attitudeOverride,
new DateBasedManeuverTriggers(constantThrustPropulsionModel.getName(), date, duration),
constantThrustPropulsionModel);
}
/** Simple constructor for a constant direction and constant thrust.
* <p>
* It uses an {@link AbstractConstantThrustPropulsionModel} and
* the maneuver triggers {@link DateBasedManeuverTriggers}
* </p><p>
* The names of the maneuver (and thus its parameter drivers) are extracted
* from the propulsion model or the maneuver triggers.
* Propulsion model name is evaluated first, if it isn't empty, it becomes the name of the maneuver.
* In that case the name in the maneuver triggers should be the same or empty, otherwise this could be
* misleading when retrieving estimated parameters by their names.
* </p>
* @param attitudeOverride the attitude provider to use for the maneuver, or
* null if the attitude from the propagator should be used
* @param dateBasedManeuverTriggers user-defined maneuver triggers object based on a start and end date
* @param constantThrustPropulsionModel user-defined constant thrust propulsion model
*/
public ConstantThrustManeuver(final AttitudeProvider attitudeOverride,
final DateBasedManeuverTriggers dateBasedManeuverTriggers,
final AbstractConstantThrustPropulsionModel constantThrustPropulsionModel) {
super(attitudeOverride, dateBasedManeuverTriggers, constantThrustPropulsionModel);
}
/** Get the thrust vector (N) in S/C frame.
* @return thrust vector (N) in S/C frame.
*/
public Vector3D getThrustVector() {
return ((AbstractConstantThrustPropulsionModel) getPropulsionModel()).getThrustVector();
}
/** Get the thrust.
* @return thrust force (N).
*/
public double getThrust() {
return getThrustVector().getNorm();
}
/** Get the specific impulse.
* @return specific impulse (s).
*/
public double getISP() {
return ((AbstractConstantThrustPropulsionModel) getPropulsionModel()).getIsp();
}
/** Get the flow rate.
* @return flow rate (negative, kg/s).
*/
public double getFlowRate() {
return ((AbstractConstantThrustPropulsionModel) getPropulsionModel()).getFlowRate();
}
/** Get the direction.
* @return the direction
* @since 9.2
*/
public Vector3D getDirection() {
return getThrustVector().normalize();
}
/** Get the start date.
* @return the start date
* @since 9.2
*/
public AbsoluteDate getStartDate() {
return ((DateBasedManeuverTriggers) getManeuverTriggers()).getStartDate();
}
/** Get the end date.
* @return the end date
* @since 9.2
*/
public AbsoluteDate getEndDate() {
return ((DateBasedManeuverTriggers) getManeuverTriggers()).getEndDate();
}
/** Get the duration of the maneuver (s).
* duration = endDate - startDate
* @return the duration of the maneuver (s)
* @since 9.2
*/
public double getDuration() {
return ((DateBasedManeuverTriggers) getManeuverTriggers()).getDuration();
}
/** Check if maneuvering is on.
* @param s current state
* @return true if maneuver is on at this state
* @since 10.1
*/
public boolean isFiring(final SpacecraftState s) {
return isFiring(s.getDate());
}
/** Check if maneuvering is on.
* @param s current state
* @param <T> type of the field elements
* @return true if maneuver is on at this state
* @since 10.1
*/
public <T extends CalculusFieldElement<T>> boolean isFiring(final FieldSpacecraftState<T> s) {
return isFiring(s.getDate().toAbsoluteDate());
}
/** Check if maneuvering is on.
* @param date current date
* @return true if maneuver is on at this date
* @since 10.1
*/
public boolean isFiring(final AbsoluteDate date) {
return getManeuverTriggers().isFiring(date, new double[] {});
}
}