public class EventShifter extends AbstractDetector
This class wraps an event detector to slightly shift the events occurrences times.
A typical use case is for handling operational delays before or after some physical event really occurs.
For example, the satellite attitude mode may be switched from sun pointed to spin-stabilized a few minutes before
eclipse entry, and switched back to sun pointed a few minutes after eclipse exit. This behavior is handled by
wrapping an eclipse detector into an instance of this class with a positive times shift for
increasing events (eclipse exit) and a negative times shift for decreasing events (eclipse entry).
Propagator.addEventDetector(EventDetector),
EventDetector,
Serialized FormEventDetector.ActionDEFAULT_MAXCHECK, DEFAULT_THRESHOLDDECREASING, INCREASING, INCREASING_DECREASING| Constructor and Description |
|---|
EventShifter(EventDetector detectorIn,
boolean useShiftedStatesIn,
double increasingTimeShift,
double decreasingTimeShift)
Build a new instance.
|
| Modifier and Type | Method and Description |
|---|---|
EventDetector.Action |
eventOccurred(SpacecraftState s,
boolean increasing,
boolean forward)
Handle an event and choose what to do next.
|
double |
g(SpacecraftState s)
Compute the value of the switching function.
|
double |
getDecreasingTimeShift()
Get the decreasing events time shift.
|
double |
getIncreasingTimeShift()
Get the increasing events time shift.
|
void |
init(SpacecraftState s0,
AbsoluteDate t)
Initialize event handler at the start of a propagation.
|
boolean |
shouldBeRemoved()
This method is called after
EventDetector.eventOccurred(fr.cnes.sirius.patrius.propagation.SpacecraftState, boolean, boolean) has been triggered. |
getMaxCheckInterval, getMaxIterationCount, getSlopeSelection, getThreshold, resetStatepublic EventShifter(EventDetector detectorIn, boolean useShiftedStatesIn, double increasingTimeShift, double decreasingTimeShift)
The max check interval, the convergence threshold of the
raw unshifted events will be used for the shifted event. When an event occurs, the
eventOccurred method of the raw unshifted events will
be called (with spacecraft state at either the shifted or the unshifted event date depending on the
useShiftedStates parameter).
detectorIn - event detector for the raw unshifted eventuseShiftedStatesIn - if true, the state provided to eventOccurred
method of
the detector will remain shifted, otherwise it will
be unshifted to correspond to the underlying raw event.increasingTimeShift - increasing events time shift.decreasingTimeShift - decreasing events time shift.public double getIncreasingTimeShift()
public double getDecreasingTimeShift()
public void init(SpacecraftState s0, AbsoluteDate t)
This method is called once at the start of the propagation. It may be used by the event handler to initialize some internal data if needed.
init in interface EventDetectorinit in class AbstractDetectors0 - initial statet - target time for the integrationpublic boolean shouldBeRemoved()
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.shouldBeRemoved in interface EventDetectorshouldBeRemoved in class AbstractDetectorpublic EventDetector.Action eventOccurred(SpacecraftState s, boolean increasing, boolean forward) throws PatriusException
The scheduling between this method and the PatriusStepHandler method handleStep() is to call this method first
and handleStep afterwards. This
scheduling allows the propagator to pass true as the isLast parameter to the step
handler to make it aware the step will be the last one if this method returns EventDetector.Action.STOP.
As the interpolator may be used to navigate back throughout the last step (as
OrekitStepNormalizer does for example),
user code called by this method and user code called by step handlers may experience apparently out of order
values of the independent time variable. As an example, if the same user object implements both this
EventDetector interface and the
OrekitFixedStepHandler interface, a
forward integration may call its eventOccurred method with a state at 2000-01-01T00:00:10
first and call its handleStep method with a state at 2000-01-01T00:00:09 afterwards. Such out of
order calls are limited to the size of the integration step for
variable step handlers and to the size of
the fixed step for fixed step
handlers.
eventOccurred in interface EventDetectoreventOccurred in class AbstractDetectors - the current state information: date, kinematics, attitude for forces
and events computation, mass provider, and additional statesincreasing - 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.EventDetector.Action.STOP, EventDetector.Action.RESET_STATE,
EventDetector.Action.RESET_DERIVATIVES, EventDetector.Action.CONTINUEPatriusException - if some specific error occurspublic double g(SpacecraftState s) throws PatriusException
g in interface EventDetectorg in class AbstractDetectors - the current state information: date, kinematics, attitude for forces
and events computation, mass provider, and additional statesPatriusException - if some specific error occursCopyright © 2017 CNES. All rights reserved.