org.orekit.forces.maneuvers.trigger

Class EventBasedManeuverTriggers

java.lang.Object

org.orekit.forces.maneuvers.trigger.EventBasedManeuverTriggers

All Implemented Interfaces:

ManeuverTriggers, EventHandler<EventDetector>

public class EventBasedManeuverTriggers
extends Object
implements ManeuverTriggers, EventHandler<EventDetector>

Maneuver triggers based on start and stop detectors. This allow a succession of burn interval. The thruster starts firing when the start detector becomes positive. The thruster stops firing when the stop detector becomes positive. The 2 detectors should not be positive at the same time. A date detector is not suited as it does not delimit an interval. They can be both negative at the same time.

Since:

10.2

Author:

Mikael Fillastre, Andrea Fiorentino

Constructor Summary

Constructors

Constructor and Description
EventBasedManeuverTriggers(AbstractDetector<? extends EventDetector> startFiringDetector, AbstractDetector<? extends EventDetector> stopFiringDetector) Constructor.
EventBasedManeuverTriggers(AbstractDetector<? extends EventDetector> startFiringDetector, AbstractDetector<? extends EventDetector> stopFiringDetector, boolean allowBackwardPropagation) Constructor.

Method Summary

Modifier and Type	Method and Description
protected void	checkInitialFiringState(SpacecraftState initialState) Method to set the firing state on initialization.
Action	eventOccurred(SpacecraftState s, EventDetector detector, boolean increasing) eventOccurred method mirrors the same interface method as in EventDetector and its subclasses, but with an additional parameter that allows the calling method to pass in an object from the detector which would have potential additional data to allow the implementing class to determine the correct return state.
Stream<EventDetector>	getEventsDetectors() Get the event detectors associated with the triggers.
<T extends CalculusFieldElement<T>> Stream<FieldEventDetector<T>>	getFieldEventsDetectors(Field<T> field) Get the event detectors associated with the triggers.
AbstractDetector<? extends EventDetector>	getStartFiringDetector() Getter for the start firing detector.
AbstractDetector<? extends EventDetector>	getStopFiringDetector() Getter for the stop firing detector.
AbsoluteDate	getTriggeredEnd() Getter for the triggered date of engine stop.
AbsoluteDate	getTriggeredStart() Getter triggered date of engine start.
void	init(SpacecraftState initialState, AbsoluteDate target) Initialization method called at propagation start.
boolean	isFiring(AbsoluteDate date) Check if maneuvering is on.
boolean	isFiring(AbsoluteDate date, double[] parameters) Find out if the maneuver is firing or not.
<T extends CalculusFieldElement<T>> boolean	isFiring(FieldAbsoluteDate<T> date, T[] parameters) Find out if the maneuver is firing or not.
protected boolean	isFiringOnInitialState(SpacecraftState initialState) Method to check if the thruster is firing on initialization.
void	setFiring(boolean firing, AbsoluteDate date) Set the firing start or end date depending on the firing flag.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.orekit.forces.maneuvers.trigger.ManeuverTriggers

getName, getParametersDrivers, init

Methods inherited from interface org.orekit.propagation.events.handlers.EventHandler

init, resetState

Constructor Detail

EventBasedManeuverTriggers

public EventBasedManeuverTriggers(AbstractDetector<? extends EventDetector> startFiringDetector,
                                  AbstractDetector<? extends EventDetector> stopFiringDetector)

Constructor.

This legacy constructor forbids backward propagation.

Parameters:

startFiringDetector - Detector to start firing, only detect increasing sign change

stopFiringDetector - Detector to stop firing, only detect increasing sign change. e.g. it can be a negate detector of the start detector.

EventBasedManeuverTriggers

public EventBasedManeuverTriggers(AbstractDetector<? extends EventDetector> startFiringDetector,
                                  AbstractDetector<? extends EventDetector> stopFiringDetector,
                                  boolean allowBackwardPropagation)

Constructor.

Parameters:

startFiringDetector - Detector to start firing, only detect increasing sign change

stopFiringDetector - Detector to stop firing, only detect increasing sign change. e.g. it can be a negate detector of the start detector.

allowBackwardPropagation - if true, backward propagation is allowed

Since:

11.1

Method Detail

getStartFiringDetector

public AbstractDetector<? extends EventDetector> getStartFiringDetector()

Getter for the start firing detector.

Returns:

Detectors to start firing,

getStopFiringDetector

public AbstractDetector<? extends EventDetector> getStopFiringDetector()

Getter for the stop firing detector.

Returns:

Detectors to stop firing

init

public void init(SpacecraftState initialState,
                 AbsoluteDate target)

Initialization method called at propagation start.

The default implementation does nothing.

Specified by:

init in interface ManeuverTriggers

Parameters:

initialState - initial spacecraft state (at the start of propagation).

target - date of propagation. Not equal to initialState.getDate().

checkInitialFiringState

protected void checkInitialFiringState(SpacecraftState initialState)

Method to set the firing state on initialization. can be overloaded by sub classes.

Parameters:

initialState - initial spacecraft state

isFiringOnInitialState

protected boolean isFiringOnInitialState(SpacecraftState initialState)

Method to check if the thruster is firing on initialization. can be called by sub classes

Parameters:

initialState - initial spacecraft state

Returns:

true if firing

getEventsDetectors

public Stream<EventDetector> getEventsDetectors()

Get the event detectors associated with the triggers.

Specified by:

getEventsDetectors in interface ManeuverTriggers

Returns:

the event detectors

getFieldEventsDetectors

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

Get the event detectors associated with the triggers.

Specified by:

getFieldEventsDetectors in interface ManeuverTriggers

Type Parameters:

T - type of the field elements

Parameters:

field - field to which the state belongs

Returns:

the event detectors

setFiring

public void setFiring(boolean firing,
                      AbsoluteDate date)

Set the firing start or end date depending on the firing flag. There is no effect if the firing state is not changing.

Parameters:

firing - true to start a maneuver, false to stop

date - date of event

isFiring

public boolean isFiring(AbsoluteDate date,
                        double[] parameters)

Find out if the maneuver is firing or not.

Specified by:

isFiring in interface ManeuverTriggers

Parameters:

date - current date

parameters - maneuver triggers parameters

Returns:

true if the maneuver is firing, false otherwise

isFiring

public <T extends CalculusFieldElement<T>> boolean isFiring(FieldAbsoluteDate<T> date,
                                                            T[] parameters)

Find out if the maneuver is firing or not.

Specified by:

isFiring in interface ManeuverTriggers

Type Parameters:

T - type of the field elements

Parameters:

date - current date

parameters - maneuver triggers parameters

Returns:

true if the maneuver is firing, false otherwise

eventOccurred

public Action eventOccurred(SpacecraftState s,
                            EventDetector detector,
                            boolean increasing)

eventOccurred method mirrors the same interface method as in EventDetector and its subclasses, but with an additional parameter that allows the calling method to pass in an object from the detector which would have potential additional data to allow the implementing class to determine the correct return state.

Specified by:

eventOccurred in interface EventHandler<EventDetector>

Parameters:

s - SpaceCraft state to be used in the evaluation

detector - object with appropriate type that can be used in determining correct return state

increasing - with the event occurred in an "increasing" or "decreasing" slope direction

Returns:

the Action that the calling detector should pass back to the evaluation system

isFiring

public boolean isFiring(AbsoluteDate date)

Check if maneuvering is on.

Parameters:

date - current date

Returns:

true if maneuver is on at this date

getTriggeredEnd

public AbsoluteDate getTriggeredEnd()

Getter for the triggered date of engine stop.

Returns:

Triggered date of engine stop

getTriggeredStart

public AbsoluteDate getTriggeredStart()

Getter triggered date of engine start.

Returns:

Triggered date of engine start