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

Class FieldBoundedCartesianEnergy<T extends CalculusFieldElement<T>>

java.lang.Object

org.orekit.control.indirect.adjoint.cost.FieldBoundedCartesianEnergy<T>

Type Parameters:

T - field type

All Implemented Interfaces:

FieldCartesianCost<T>

public class FieldBoundedCartesianEnergy<T extends CalculusFieldElement<T>>
extends Object

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:

13.0

Author:

Romain Serra

See Also:

FieldUnboundedCartesianEnergy, BoundedCartesianEnergy

Constructor Summary

Constructors

Constructor	Description
FieldBoundedCartesianEnergy(String name, T massFlowRateFactor, T maximumThrustMagnitude)	Constructor.
FieldBoundedCartesianEnergy(String name, T massFlowRateFactor, T maximumThrustMagnitude, FieldEventDetectionSettings<T> eventDetectionSettings)	Constructor.

Method Summary

Modifier and Type	Method	Description
String	getAdjointName()	Getter for adjoint vector name.
FieldEventDetectionSettings<T>	getEventDetectionSettings()	Getter for event detection settings.
protected T	getFieldAdjointVelocityNorm(T[] adjointVariables)	Computes the Euclidean norm of the adjoint velocity vector.
Stream<FieldEventDetector<T>>	getFieldEventDetectors(Field<T> field)	Get the detectors needed for propagation.
T	getFieldHamiltonianContribution(T[] adjointVariables, T mass)	Computes the Hamiltonian contribution of the cost function.
FieldVector3D<T>	getFieldThrustAccelerationVector(T[] adjointVariables, T mass)	Computes the thrust acceleration vector in propagation frame from the adjoint variables and the mass.
protected FieldVector3D<T>	getFieldThrustDirection(T[] adjointVariables)	Computes the direction of thrust.
protected T	getFieldThrustForceNorm(T[] adjointVariables, T mass)	Computes the Euclidean norm of the thrust force.
T	getMassFlowRateFactor()	Getter for mass flow rate factor.
T	getMaximumThrustMagnitude()	Getter for maximum thrust magnitude.
BoundedCartesianEnergy	toCartesianCost()	Method returning equivalent in non-Field.
void	updateFieldAdjointDerivatives(T[] adjointVariables, T mass, T[] adjointDerivatives)	Update the adjoint derivatives if necessary.

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.FieldCartesianCost

getAdjointDimension

Constructor Detail

FieldBoundedCartesianEnergy

public FieldBoundedCartesianEnergy(String name,
                                   T massFlowRateFactor,
                                   T maximumThrustMagnitude,
                                   FieldEventDetectionSettings<T> eventDetectionSettings)

Constructor.

Parameters:

name - name

massFlowRateFactor - mass flow rate factor

maximumThrustMagnitude - maximum thrust magnitude

eventDetectionSettings - singularity event detection settings

FieldBoundedCartesianEnergy

public FieldBoundedCartesianEnergy(String name,
                                   T massFlowRateFactor,
                                   T maximumThrustMagnitude)

Constructor.

Parameters:

name - name

massFlowRateFactor - mass flow rate factor

maximumThrustMagnitude - maximum thrust magnitude

Method Detail

getMaximumThrustMagnitude

public T getMaximumThrustMagnitude()

Getter for maximum thrust magnitude.

Returns:

maximum thrust

getFieldThrustForceNorm

protected T getFieldThrustForceNorm(T[] adjointVariables,
                                    T mass)

Computes the Euclidean norm of the thrust force.

Parameters:

adjointVariables - adjoint vector

mass - mass

Returns:

norm of thrust

getFieldEventDetectors

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

Get the detectors needed for propagation.

Parameters:

field - field

Returns:

event detectors

toCartesianCost

public BoundedCartesianEnergy toCartesianCost()

Method returning equivalent in non-Field.

Returns:

cost function for non-Field applications

getAdjointName

public String getAdjointName()

Getter for adjoint vector name.

Specified by:

getAdjointName in interface FieldCartesianCost<T extends CalculusFieldElement<T>>

Returns:

name

getMassFlowRateFactor

public T getMassFlowRateFactor()

Getter for mass flow rate factor. It is negated and multiplied by the thrust force magnitude to obtain the mass time derivative. The fact that it is a constant means that the exhaust speed is assumed to be independent of time.

Specified by:

getMassFlowRateFactor in interface FieldCartesianCost<T extends CalculusFieldElement<T>>

Returns:

mass flow rate factor

getEventDetectionSettings

public FieldEventDetectionSettings<T> getEventDetectionSettings()

Getter for event detection settings.

Returns:

detection settings.

getFieldThrustAccelerationVector

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

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

Specified by:

getFieldThrustAccelerationVector in interface FieldCartesianCost<T extends CalculusFieldElement<T>>

Parameters:

adjointVariables - adjoint vector

mass - mass

Returns:

thrust vector

getFieldThrustDirection

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

Computes the direction of thrust.

Parameters:

adjointVariables - adjoint vector

Returns:

thrust direction

updateFieldAdjointDerivatives

public void updateFieldAdjointDerivatives(T[] adjointVariables,
                                          T mass,
                                          T[] adjointDerivatives)

Update the adjoint derivatives if necessary.

Specified by:

updateFieldAdjointDerivatives in interface FieldCartesianCost<T extends CalculusFieldElement<T>>

Parameters:

adjointVariables - adjoint vector

mass - mass

adjointDerivatives - derivatives to update

getFieldAdjointVelocityNorm

protected T getFieldAdjointVelocityNorm(T[] adjointVariables)

Computes the Euclidean norm of the adjoint velocity vector.

Parameters:

adjointVariables - adjoint vector

Returns:

norm of adjoint velocity

getFieldHamiltonianContribution

public T getFieldHamiltonianContribution(T[] adjointVariables,
                                         T mass)

Computes the Hamiltonian contribution of the cost function.

Specified by:

getFieldHamiltonianContribution in interface FieldCartesianCost<T extends CalculusFieldElement<T>>

Parameters:

adjointVariables - adjoint vector

mass - mass

Returns:

contribution to Hamiltonian