Package org.orekit.control.indirect.adjoint

Class CartesianAdjointDerivativesProvider

java.lang.Object

org.orekit.control.indirect.adjoint.AbstractCartesianAdjointDerivativesProvider

org.orekit.control.indirect.adjoint.CartesianAdjointDerivativesProvider

All Implemented Interfaces:

AdditionalDerivativesProvider

public class CartesianAdjointDerivativesProvider
extends AbstractCartesianAdjointDerivativesProvider
implements AdditionalDerivativesProvider

Class defining the adjoint dynamics, as defined in the Pontryagin Maximum Principle, in the case where Cartesian coordinates in an inertial frame are the dependent variable. The time derivatives of the adjoint variables are obtained by differentiating the so-called Hamiltonian. They depend on the force model and the cost being minimized. For the former, it is the user's responsibility to make sure the provided CartesianAdjointEquationTerm are consistent with the ForceModel. For the latter, the cost function is represented through the interface CartesianCost.

Since:

12.2

Author:

Romain Serra

See Also:

AdditionalDerivativesProvider, NumericalPropagator

Constructor Summary

Constructors

Constructor	Description
CartesianAdjointDerivativesProvider(CartesianCost cost, CartesianAdjointEquationTerm... adjointEquationTerms)	Constructor.

Method Summary

Modifier and Type	Method	Description
CombinedDerivatives	combinedDerivatives(SpacecraftState state)	Compute the derivatives related to the additional state (and optionally main state increments).
double	evaluateHamiltonian(SpacecraftState state)	Evaluate the Hamiltonian from Pontryagin's Maximum Principle.
void	init(SpacecraftState initialState, AbsoluteDate target)	Initialize the generator at the start of propagation.

Methods inherited from class org.orekit.control.indirect.adjoint.AbstractCartesianAdjointDerivativesProvider

getCost, getDimension, getName

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.orekit.propagation.integration.AdditionalDerivativesProvider

getDimension, getName, yields

Constructor Detail

CartesianAdjointDerivativesProvider

public CartesianAdjointDerivativesProvider(CartesianCost cost,
                                           CartesianAdjointEquationTerm... adjointEquationTerms)

Constructor.

Parameters:

cost - cost function

adjointEquationTerms - terms contributing to the adjoint equations. If none, then the propagator should have no forces, not even a Newtonian attraction.

Method Detail

init

public void init(SpacecraftState initialState,
                 AbsoluteDate target)

Initialize the generator at the start of propagation.

Specified by:

init in interface AdditionalDerivativesProvider

Parameters:

initialState - initial state information at the start of propagation

target - date of propagation

combinedDerivatives

public CombinedDerivatives combinedDerivatives(SpacecraftState state)

Compute the derivatives related to the additional state (and optionally main state increments).

Specified by:

combinedDerivatives in interface AdditionalDerivativesProvider

Parameters:

state - current state information: date, kinematics, attitude, and additional states this equations depend on (according to the yields method)

Returns:

computed combined derivatives, which may include some incremental coupling effect to add to main state derivatives

evaluateHamiltonian

public double evaluateHamiltonian(SpacecraftState state)

Evaluate the Hamiltonian from Pontryagin's Maximum Principle.

Parameters:

state - state assumed to hold the adjoint variables

Returns:

Hamiltonian