Package org.orekit.control.indirect.adjoint.cost

Class BoundedCartesianEnergy

java.lang.Object

org.orekit.control.indirect.adjoint.cost.AbstractCartesianCost

org.orekit.control.indirect.adjoint.cost.BoundedCartesianEnergy

All Implemented Interfaces:

CartesianCost, EventDetectorsProvider

public class BoundedCartesianEnergy
extends AbstractCartesianCost

Class for bounded energy cost with Cartesian coordinates. An energy cost is proportional to the integral over time of the squared Euclidean norm of the control vector, often scaled with 1/2. This type of cost is not optimal in terms of mass consumption, however its solutions showcase a smoother behavior favorable for convergence in shooting techniques. Here, the control vector is chosen as the thrust force divided by the maximum thrust magnitude and expressed in the propagation frame. It has a unit Euclidean norm.

Since:

12.2

Author:

Romain Serra

See Also:

UnboundedCartesianEnergyNeglectingMass

Field Summary

Fields inherited from interface org.orekit.propagation.events.EventDetectorsProvider

DATATION_ACCURACY

Constructor Summary

Constructors

Constructor	Description
BoundedCartesianEnergy(String name, double massFlowRateFactor, double maximumThrustMagnitude)	Constructor.
BoundedCartesianEnergy(String name, double massFlowRateFactor, double maximumThrustMagnitude, EventDetectionSettings eventDetectionSettings)	Constructor.

Method Summary

Modifier and Type	Method	Description
EventDetectionSettings	getEventDetectionSettings()	Getter for event detection settings.
Stream<EventDetector>	getEventDetectors()	Get the discrete events related to the model.
<T extends CalculusFieldElement<T>> Stream<FieldEventDetector<T>>	getFieldEventDetectors(Field<T> field)	Get the discrete events related to the model.
<T extends CalculusFieldElement<T>> T	getFieldHamiltonianContribution(T[] adjointVariables, T mass)	Computes the Hamiltonian contribution of the cost function.
<T extends CalculusFieldElement<T>> FieldVector3D<T>	getFieldThrustAccelerationVector(T[] adjointVariables, T mass)	Computes the thrust acceleration vector in propagation frame from the adjoint variables and the mass.
protected <T extends CalculusFieldElement<T>> FieldVector3D<T>	getFieldThrustDirection(T[] adjointVariables)	Computes the direction of thrust.
protected <T extends CalculusFieldElement<T>> T	getFieldThrustForceNorm(T[] adjointVariables, T mass)	Computes the Euclidean norm of the thrust force.
double	getHamiltonianContribution(double[] adjointVariables, double mass)	Computes the Hamiltonian contribution of the cost function.
Vector3D	getThrustAccelerationVector(double[] adjointVariables, double mass)	Computes the thrust acceleration vector in propagation frame from the adjoint variables and the mass.
protected Vector3D	getThrustDirection(double[] adjointVariables)	Computes the direction of thrust.
protected double	getThrustForceNorm(double[] adjointVariables, double mass)	Computes the Euclidean norm of the thrust force.
void	updateAdjointDerivatives(double[] adjointVariables, double mass, double[] adjointDerivatives)	Update the adjoint derivatives if necessary.
<T extends CalculusFieldElement<T>> void	updateFieldAdjointDerivatives(T[] adjointVariables, T mass, T[] adjointDerivatives)	Update the adjoint derivatives if necessary.

Methods inherited from class org.orekit.control.indirect.adjoint.cost.AbstractCartesianCost

getAdjointName, getAdjointVelocityNorm, getFieldAdjointVelocityNorm, getMassFlowRateFactor

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.orekit.control.indirect.adjoint.cost.CartesianCost

getAdjointDimension

Methods inherited from interface org.orekit.propagation.events.EventDetectorsProvider

getEventDetectors, getFieldEventDetectors

Constructor Detail

BoundedCartesianEnergy

public BoundedCartesianEnergy(String name,
                              double massFlowRateFactor,
                              double maximumThrustMagnitude,
                              EventDetectionSettings eventDetectionSettings)

Constructor.

Parameters:

name - name

massFlowRateFactor - mass flow rate factor

maximumThrustMagnitude - maximum thrust magnitude

eventDetectionSettings - singularity event detection settings

BoundedCartesianEnergy

public BoundedCartesianEnergy(String name,
                              double massFlowRateFactor,
                              double maximumThrustMagnitude)

Constructor.

Parameters:

name - name

massFlowRateFactor - mass flow rate factor

maximumThrustMagnitude - maximum thrust magnitude

Method Detail

getThrustForceNorm

protected double getThrustForceNorm(double[] adjointVariables,
                                    double mass)

Computes the Euclidean norm of the thrust force.

Parameters:

adjointVariables - adjoint vector

mass - mass

Returns:

norm of thrust

getFieldThrustForceNorm

protected <T extends CalculusFieldElement<T>> T getFieldThrustForceNorm(T[] adjointVariables,
                                                                        T mass)

Computes the Euclidean norm of the thrust force.

Type Parameters:

T - field type

Parameters:

adjointVariables - adjoint vector

mass - mass

Returns:

norm of thrust

getEventDetectors

public Stream<EventDetector> getEventDetectors()

Get the discrete events related to the model.

This method is not intended to be called several time, only once by a propagator, as it has the side effect of rebuilding the events detectors when called

Returns:

stream of event detectors

getFieldEventDetectors

public <T extends CalculusFieldElement<T>> Stream<FieldEventDetector<T>> getFieldEventDetectors(Field<T> field)

Get the discrete events related to the model.

This method is not intended to be called several time, only once by a propagator, as it has the side effect of rebuilding the events detectors when called

Type Parameters:

T - extends CalculusFieldElement<T>

Parameters:

field - field to which the state belongs

Returns:

stream of event detectors

getEventDetectionSettings

public EventDetectionSettings getEventDetectionSettings()

Getter for event detection settings.

Returns:

detection settings.

getThrustAccelerationVector

public Vector3D getThrustAccelerationVector(double[] adjointVariables,
                                            double mass)

Computes the thrust acceleration vector in propagation frame from the adjoint variables and the mass.

Parameters:

adjointVariables - adjoint vector

mass - mass

Returns:

thrust vector

getFieldThrustAccelerationVector

public <T extends CalculusFieldElement<T>> FieldVector3D<T> getFieldThrustAccelerationVector(T[] adjointVariables,
                                                                                             T mass)

Computes the thrust acceleration vector in propagation frame from the adjoint variables and the mass.

Type Parameters:

T - field type

Parameters:

adjointVariables - adjoint vector

mass - mass

Returns:

thrust vector

getThrustDirection

protected Vector3D getThrustDirection(double[] adjointVariables)

Computes the direction of thrust.

Parameters:

adjointVariables - adjoint vector

Returns:

thrust direction

getFieldThrustDirection

protected <T extends CalculusFieldElement<T>> FieldVector3D<T> getFieldThrustDirection(T[] adjointVariables)

Computes the direction of thrust.

Type Parameters:

T - field type

Parameters:

adjointVariables - adjoint vector

Returns:

thrust direction

updateAdjointDerivatives

public void updateAdjointDerivatives(double[] adjointVariables,
                                     double mass,
                                     double[] adjointDerivatives)

Update the adjoint derivatives if necessary.

Parameters:

adjointVariables - adjoint vector

mass - mass

adjointDerivatives - derivatives to update

updateFieldAdjointDerivatives

public <T extends CalculusFieldElement<T>> void updateFieldAdjointDerivatives(T[] adjointVariables,
                                                                              T mass,
                                                                              T[] adjointDerivatives)

Update the adjoint derivatives if necessary.

Type Parameters:

T - field type

Parameters:

adjointVariables - adjoint vector

mass - mass

adjointDerivatives - derivatives to update

getHamiltonianContribution

public double getHamiltonianContribution(double[] adjointVariables,
                                         double mass)

Computes the Hamiltonian contribution of the cost function.

Parameters:

adjointVariables - adjoint vector

mass - mass

Returns:

contribution to Hamiltonian

getFieldHamiltonianContribution

public <T extends CalculusFieldElement<T>> T getFieldHamiltonianContribution(T[] adjointVariables,
                                                                             T mass)

Computes the Hamiltonian contribution of the cost function.

Type Parameters:

T - field type

Parameters:

adjointVariables - adjoint vector

mass - mass

Returns:

contribution to Hamiltonian