fr.cnes.sirius.patrius.events.detectors

Class NullMassDetector

java.lang.Object

fr.cnes.sirius.patrius.events.AbstractDetector

fr.cnes.sirius.patrius.events.detectors.NullMassDetector

All Implemented Interfaces:

EventDetector, Serializable

public class NullMassDetector
extends AbstractDetector

This class creates an event detector that detects when the global mass of the satellite becomes null. This detector is automatically added (in first position) to every propagator and stops the propagation once it detects a null global mass. Since the initial mass is positive or null, the first time where g = 0 will indicate the first time when the mass becomes null.

Since:

2.3

Version:

$Id: NullMassDetector.java 18094 2017-10-02 17:18:57Z bignon $

Author:

Sophie LAURENS

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface fr.cnes.sirius.patrius.events.EventDetector

EventDetector.Action

Field Summary

Fields inherited from class fr.cnes.sirius.patrius.events.AbstractDetector

actionAtEntry, actionAtExit, DEFAULT_MAXITER, removeAtEntry, removeAtExit, shouldBeRemovedFlag

Fields inherited from interface fr.cnes.sirius.patrius.events.EventDetector

DECREASING, INCREASING, INCREASING_DECREASING

Constructor Summary

Constructors

Constructor and Description
NullMassDetector(double maxCheck, double threshold, MassProvider massModel) Inherited constructor.
NullMassDetector(int slopeSelection, double maxCheck, double threshold, MassProvider massModel) Inherited constructor.
NullMassDetector(MassProvider massModel) Build a new instance (based on DateDetector).

Method Summary

Modifier and Type	Method and Description
EventDetector	copy() A copy of the detector.
EventDetector.Action	eventOccurred(SpacecraftState s, boolean increasing, boolean forward) If the global mass of the satellite becomes negative, the propagation is stopped.
double	g(SpacecraftState s) Compute the value of the switching function.
boolean	isTriggered() Returns true if detector has been triggered.
boolean	shouldBeRemoved() This method is called after EventDetector.eventOccurred(fr.cnes.sirius.patrius.propagation.SpacecraftState, boolean, boolean) has been triggered.

Methods inherited from class fr.cnes.sirius.patrius.events.AbstractDetector

filterEvent, getActionAtEntry, getActionAtExit, getMaxCheckInterval, getMaxIterationCount, getSlopeSelection, getThreshold, init, isRemoveAtEntry, isRemoveAtExit, logEventsOverTimeInterval, resetState, setMaxCheckInterval, setMaxIter

Methods inherited from class java.lang.Object

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

Constructor Detail

NullMassDetector

public NullMassDetector(double maxCheck,
                        double threshold,
                        MassProvider massModel)

Inherited constructor.

Parameters:

maxCheck - maximum checking interval (s)

threshold - convergence threshold (s)

massModel - mass model

NullMassDetector

public NullMassDetector(int slopeSelection,
                        double maxCheck,
                        double threshold,
                        MassProvider massModel)

Inherited constructor.

Parameters:

slopeSelection - g-function slope selection (0, 1, or 2)

maxCheck - maximum checking interval (s)

threshold - convergence threshold (s)

massModel - mass model

NullMassDetector

public NullMassDetector(MassProvider massModel)

Build a new instance (based on DateDetector).

This constructor is dedicated to single date detection. MaxCheck is set to 10.e9, so almost no other date can be added. Tolerance is set to 10.e-10.

Parameters:

massModel - mass model

Method Detail

eventOccurred

public EventDetector.Action eventOccurred(SpacecraftState s,
                                          boolean increasing,
                                          boolean forward)

If the global mass of the satellite becomes negative, the propagation is stopped.

Specified by:

eventOccurred in interface EventDetector

Overrides:

eventOccurred in class AbstractDetector

Parameters:

s - the current state information : date, kinematics, attitude

increasing - if true, the value of the switching function increases when times increases around event (note that increase is measured with respect to physical time, not with respect to propagation which may go backward in time)

forward - if true, the integration variable (time) increases during integration.

Returns:

EventDetector.Action.STOP

g

public double g(SpacecraftState s)
         throws PatriusException

Compute the value of the switching function.

Specified by:

g in interface EventDetector

Specified by:

g in class AbstractDetector

Parameters:

s - the current state information: date, kinematics, attitude

Returns:

value of the switching function

Throws:

PatriusException - if some specific error occurs

isTriggered

public final boolean isTriggered()

Returns true if detector has been triggered.

Returns:

true if detector has been triggered

shouldBeRemoved

public boolean shouldBeRemoved()

This method is called after EventDetector.eventOccurred(fr.cnes.sirius.patrius.propagation.SpacecraftState, boolean, boolean) has been triggered. It returns true if the current detector should be removed after first event detection. WARNING: this method can be called only once a event has been triggered. Before, the value is not available.

Specified by:

shouldBeRemoved in interface EventDetector

Overrides:

shouldBeRemoved in class AbstractDetector

Returns:

true if the current detector should be removed after first event detection

copy

public EventDetector copy()

A copy of the detector. By default copy is deep. If not, detector javadoc will specify which attribute is not fully copied. In that case, the attribute reference is passed.

The following attributes are not deeply copied:

• mass: MassProvider

Returns:

a copy of the detector.