Package org.orekit.forces.maneuvers

Class ImpulseManeuver

  • All Implemented Interfaces:
    EventDetector
    public class ImpulseManeuver
extends Object
implements EventDetector
    Impulse maneuver model.

    This class implements an impulse maneuver as a discrete event that can be provided to any Propagator.

    The maneuver is executed when an underlying is triggered, in which case this class will generate a RESET_STATE event. By default, the detection settings are those of the trigger. In the simple cases, the underlying event detector may be a basic date event, but it can also be a more elaborate apside event for apogee maneuvers for example.

    The maneuver is defined by a single velocity increment. If no AttitudeProvider is given, the current attitude of the spacecraft, defined by the current spacecraft state, will be used as the AttitudeProvider so the velocity increment should be given in the same pseudoinertial frame as the SpacecraftState used to construct the propagator that will handle the maneuver. If an AttitudeProvider is given, the velocity increment given should be defined appropriately in consideration of that provider. So, a typical case for tangential maneuvers is to provide a LOF aligned attitude provider along with a velocity increment defined in accordance with that LOF aligned attitude provider; e.g. if the LOF aligned attitude provider was constructed using LOFType.VNC the velocity increment should be provided in VNC coordinates.

    The norm through which the delta-V maps to the mass consumption is chosen via the enum Control3DVectorCostType. Default is Euclidean.

    Beware that the triggering event detector must behave properly both before and after maneuver. If for example a node detector is used to trigger an inclination maneuver and the maneuver change the orbit to an equatorial one, the node detector will fail just after the maneuver, being unable to find a node on an equatorial orbit! This is a real case that has been encountered during validation ...

    Author:
    Luc Maisonobe
    See Also:
    Propagator.addEventDetector(EventDetector)

    • Constructor Detail

      • ImpulseManeuver

        public ImpulseManeuver​(EventDetector trigger,
                       Vector3D deltaVSat,
                       double isp)
        Build a new instance.
        Parameters:
        trigger - triggering event
        deltaVSat - velocity increment in satellite frame
        isp - engine specific impulse (s)

      • ImpulseManeuver

        public ImpulseManeuver​(EventDetector trigger,
                       AttitudeProvider attitudeOverride,
                       Vector3D deltaVSat,
                       double isp)
        Build a new instance.
        Parameters:
        trigger - triggering event
        attitudeOverride - the attitude provider to use for the maneuver
        deltaVSat - velocity increment in satellite frame
        isp - engine specific impulse (s)

      • ImpulseManeuver

        public ImpulseManeuver​(EventDetector trigger,
                       AttitudeProvider attitudeOverride,
                       Vector3D deltaVSat,
                       double isp,
                       Control3DVectorCostType control3DVectorCostType)
        Build a new instance.
        Parameters:
        trigger - triggering event
        attitudeOverride - the attitude provider to use for the maneuver
        deltaVSat - velocity increment in satellite frame
        isp - engine specific impulse (s)
        control3DVectorCostType - increment's norm for mass consumption

    • Method Detail

      • withDetectionSettings

        public ImpulseManeuver withDetectionSettings​(EventDetectionSettings eventDetectionSettings)
        Creates a copy with different event detection settings.
        Parameters:
        eventDetectionSettings - new detection settings
        Returns:
        a new detector with same properties except for the detection settings

      • init

        public void init​(SpacecraftState s0,
                 AbsoluteDate t)
        Initialize event handler at the start of a propagation.

        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.

        The default implementation does nothing

        Specified by:
        init in interface EventDetector
        Parameters:
        s0 - initial state
        t - target time for the integration

      • g

        public double g​(SpacecraftState s)
        Compute the value of the switching function. This function must be continuous (at least in its roots neighborhood), as the integrator will need to find its roots to locate the events.
        Specified by:
        g in interface EventDetector
        Parameters:
        s - the current state information: date, kinematics, attitude
        Returns:
        value of the switching function

      • finish

        public void finish​(SpacecraftState state)
        This method finalizes the event detector's job.
        Specified by:
        finish in interface EventDetector
        Parameters:
        state - state at propagation end

      • getAttitudeOverride

        public AttitudeProvider getAttitudeOverride()
        Get the Attitude Provider to use during maneuver.
        Returns:
        the attitude provider

      • getTrigger

        public EventDetector getTrigger()
        Get the triggering event.
        Returns:
        triggering event

      • getDeltaVSat

        public Vector3D getDeltaVSat()
        Get the velocity increment in satellite frame.
        Returns:
        velocity increment in satellite frame

      • getIsp

        public double getIsp()
        Get the specific impulse.
        Returns:
        specific impulse

      • getControl3DVectorCostType

        public Control3DVectorCostType getControl3DVectorCostType()
        Get the control vector's cost type.
        Returns:
        control cost type
        Since:
        12.0