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

Class PenalizedCartesianFuelCost

java.lang.Object

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

org.orekit.control.indirect.adjoint.cost.PenalizedCartesianFuelCost

All Implemented Interfaces:

CartesianCost

Direct Known Subclasses:

LogarithmicBarrierCartesianFuel, QuadraticPenaltyCartesianFuel

public abstract class PenalizedCartesianFuelCost
extends AbstractCartesianCost

Abstract class for fuel cost with a penalty term proportional to a weight parameter epsilon. This is typically used in a continuation method, starting from epsilon equal to 1 and going towards 0 where the fuel cost is recovered. The point is to enhance convergence. The control vector is the normalized (by the upper bound on magnitude) thrust force in propagation frame. See the following reference: BERTRAND, Régis et EPENOY, Richard. New smoothing techniques for solving bang–bang optimal control problems—numerical results and statistical interpretation. Optimal Control Applications and Methods, 2002, vol. 23, no 4, p. 171-197.

Since:

13.0

Author:

Romain Serra

See Also:

• CartesianFuelCost

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	PenalizedCartesianFuelCost(String name, double massFlowRateFactor, double maximumThrustMagnitude, double epsilon)	Constructor.

Method Summary

Modifier and Type	Method	Description
abstract double	evaluatePenaltyFunction(double controlNorm)	Evaluate the penalty term (without the weight), assumed to be a function of the control norm.
double	getEpsilon()	Getter for the penalty weight epsilon.
double	getHamiltonianContribution(double[] adjointVariables, double mass)	Computes the Hamiltonian contribution to the cost function.
double	getMaximumThrustMagnitude()	Getter for maximum thrust magnitude.
protected Vector3D	getThrustDirection(double[] adjointVariables)	Computes the direction of thrust.

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

buildSwitchDetector, getAdjointDimension, getAdjointName, getAdjointVelocityNorm, 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

getCostDerivativeProvider, getEventDetectors, getThrustAccelerationVector, updateAdjointDerivatives

Constructor Details

PenalizedCartesianFuelCost

protected PenalizedCartesianFuelCost(String name,
 double massFlowRateFactor,
 double maximumThrustMagnitude,
 double epsilon)

Constructor.

Parameters:

name - adjoint name

massFlowRateFactor - mass flow rate factor

maximumThrustMagnitude - maximum thrust magnitude

epsilon - penalty weight

Method Details

getEpsilon

public double getEpsilon()

Getter for the penalty weight epsilon.

Returns:

epsilon

getMaximumThrustMagnitude

public double getMaximumThrustMagnitude()

Getter for maximum thrust magnitude.

Returns:

maximum thrust

evaluatePenaltyFunction

public abstract double evaluatePenaltyFunction(double controlNorm)

Evaluate the penalty term (without the weight), assumed to be a function of the control norm.

Parameters:

controlNorm - Euclidean norm of control vector

Returns:

penalty function

getThrustDirection

protected Vector3D getThrustDirection(double[] adjointVariables)

Computes the direction of thrust.

Parameters:

adjointVariables - adjoint vector

Returns:

thrust direction

getHamiltonianContribution

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

Computes the Hamiltonian contribution to the cost function. It equals the Lagrange-form integrand multiplied by -1.

Parameters:

adjointVariables - adjoint vector

mass - mass

Returns:

contribution to Hamiltonian