TrajectoryPhase Object

Description

The TrajectoryPhase object represents a user configurable trajectory arc for solving generic optimal control problems in FreeFlyer. Users can configure and link multiple trajectory phases with varying control models including: ballistic, simple thruster, and ideal solar sail control models. Using the TrajectoryPhase object, users can add bounds and constraints to the optimization problem to reflect real world limits when optimizing the objective function.

The TrajectoryPhase object is added to the Optimizer using the Optimizer.AddTrajectoryPhase() method. When the Optimizer.LoadEngine() method is called, all variables and constraints associated with the added TrajectoryPhases will automatically be added to the optimization problem. No further action inside of the Optimizer evaluation loop is needed from the user in order to solve the constraints originating from TrajectoryPhases.

Inheritance Hierarchy: Object->TrajectoryPhase

Available In Editions:

Mission

Timing Precision Mode

This page describes functionality in millisecond timing precision mode. Millisecond timing precision mode is deprecated and will be removed in a future release. We recommend that you migrate your Mission Plans to nanosecond timing precision mode.

Click here to see the documentation for this object in nanosecond timing precision mode.

Name	Description	Attributes
BestSolutionFirstNode	The first node in the TrajectoryPhase.BestSolutionNodes list.	Type: TrajectoryNode Access: Read-Only
BestSolutionLastNode	The last node in the TrajectoryPhase.BestSolutionNodes list.	Type: TrajectoryNode Access: Read-Only
BestSolutionNodes	The TrajectoryNodes from the best solution found by the Optimizer.	Type: Array of TrajectoryNode Access: Read-Only
CentralBodyObject	CelestialObject that defines the origin for the TrajectoryPhase's position and velocity.	Type: CelestialObject Access: Read-Only
CollocationOptions	Holds properties/methods that pertain specifically to the collocation dynamical solver.	Type: PhaseCollocationOptions Access: Read-Only
ControlModel	Used to configure the control model for the phase.	Type: PhaseControlModel Access: Read-Only
ControlVectorColorMode	The method used to color the TrajectoryPhase control vectors when viewing the TrajectoryPhase. If the 'Collocation Defect Error' or 'Dynamical Error' option is selected, the path coloring will use a gradient of red/orange/yellow/green. Red indicates collocation defect/dynamical error, and green indicates collocation defect/dynamical integrity.	Type: Variable Access: Read/Write
ControlVectorConstantColor	The color used for the control vectors when viewing the TrajectoryPhase and ControlVectorsDrawMode is set to Constant.	Type: Variable Access: Read/Write
ControlVectorMaximumLength	The maximum length in km of the control vectors in the mission view. When the control model is producing less than the maximum possible thrust, the actual length of the visualized control vector will be scaled down proportionately to the ratio of actual thrust to maximum possible thrust. You can set this property to zero to have FreeFlyer automatically scale the control vectors so that the maximum control vector length is about 1/8th the scale of the TrajectoryPhase itself in a central body-centric inertial frame.	Type: Variable Access: Read/Write Units: km
DeclaredName	The name of the object as declared.	Type: String Access: Read-Only
DeltaV	The total delta v due to the control model across the TrajectoryPhase. This value is computed via trapezoid rule integration and should be considered an approximation.	Type: Variable Access: Read-Only
DrawControlVector	Determines whether a control vector will be drawn at the current node. Note that a control vector may not exist in which case this property has no effect.	Type: Variable Access: Read/Write
DrawNode	Determines whether a tick mark will be drawn at the current node.	Type: Variable Access: Read/Write
DrawPath	Determines whether a line will be drawn between the previous node and the current node when updating a ViewWindow.	Type: Variable Access: Read/Write
FirstNode	The first node in the TrajectoryPhase.Nodes list.	Type: TrajectoryNode Access: Read-Only
LastNode	The last node in the TrajectoryPhase.Nodes list.	Type: TrajectoryNode Access: Read-Only
Name	The name displayed for this object in output windows such as views, plots, and reports.	Type: String Access: Read/Write
NodeColorMode	The method used to color the TrajectoryNodes when viewing the TrajectoryPhase. If the 'Collocation Defect Error' or 'Dynamical Error' option is selected, the path coloring will use a gradient of red/orange/yellow/green. Red indicates collocation defect/dynamical error, and green indicates collocation defect/dynamical integrity.	Type: Variable Access: Read/Write
NodeConstantColor	The color used for the nodes when viewing the TrajectoryPhase while TrajectoryPhase.NodesColorMode is set to Constant.	Type: Variable Access: Read/Write
NodeIndexToView	This index is used to determine the next node to add to the path when viewing the TrajectoryPhase in a ViewWindow. When the index is set to -999, no updates will occur for ViewWindows where the TrajectoryPhase is added. When visualizing multiple TrajectoryPhases in sequence, visualize all nodes for the first phase and then set NodeIndexToView = -999 before moving on to visualize the next phase.	Type: Variable Access: Read/Write
Nodes	The TrajectoryPhase's nodes. The nodes represent the discretized path of the TrajectoryPhase.	Type: Array of TrajectoryNode Access: Read-Only
NodeTickType	The tick mark shape to draw at each node in a Mission View.	Type: String Access: Read/Write
NodeTickWidth	The width of the tick marks.	Type: Variable Access: Read/Write
NumberOfNodes	The number of nodes in the TrajectoryPhase.	Type: Variable Access: Read-Only
ObjectId	The unique identifier for the object.	Type: Variable Access: Read-Only
ObjectType	The type of the object.	Type: String Access: Read-Only
PathColorMode	The method used to color the lines in between TrajectoryNodes when viewing the TrajectoryPhase. If the 'Collocation Defect Error' or 'Dynamical Error' option is selected, the path coloring will use a gradient of red/orange/yellow/green. Red indicates collocation defect/dynamical error, and green indicates collocation defect/dynamical integrity.	Type: Variable Access: Read/Write
PathConstantColor	The color to use for the trajectory path when viewing the TrajectoryPhase while TrajectoryPhase.PathColorMode is set to Constant.	Type: Variable Access: Read/Write
TimeOfFlight	The time of flight of the TrajectoryPhase.	Type: Variable Access: Read-Only Units: day

Name	Description
AddNode	Adds a TrajectoryNode to the underlying TrajectoryPhase.Nodes array.
AddNodes	Adds TrajectoryNodes to the underlying TrajectoryPhase.Nodes array.
AddRadiusConstraint	Constrains the radius (with respect to the central body) at the node(s) associated with the passed range.
AddRotatingStateConstraint	Adds a constraint on the TrajectoryPhase's position and velocity variables in a rotating frame of reference.
ApplyBestSolution	Overwrites the Nodes array using the BestSolutionNodes array.
ClearSavedStates	Clears previous saved states for this object.
ClearStateConstraints	Clears the TrajectoryPhase's state constraints.
ClearVariableBounds	Clears all bounds on the TrajectoryPhase's variables. Variable bounds are created whenever a Lock or SetBounds method is used.
ComputeInterphaseDeltaV	Computes the delta v between the calling TrajectoryPhase and the passed TrajectoryPhase.
GetFromFile	Load the object state from the specified FreeFlyer object file.
GetFromString	Load the object state from the specified string.
Lock	Locks all TrajectoryPhase position, velocity, mass, and epoch variables associated with the passed endpoint argument to their current values.
LockByIndices	Locks only the TrajectoryPhase variables associated with the passed endpoint and indices. Indices: 0 : x position 1 : y position 2 : z position 3 : x velocity 4 : y velocity 5 : z velocity 6 : mass 7 : epoch Any indices after 7 represent potential control variables. Certain control variables may or may not exist depending on which ControlModel is selected.
LockControlVariables	Locks TrajectoryPhase control variables.
LockEpoch	Locks the TrajectoryPhase epoch variable.
LockMass	Locks the TrajectoryPhase mass variable.
LockPosition	Locks TrajectoryPhase cartesian position variables.
LockPositionVelocity	Locks TrajectoryPhase cartesian position and velocity variables.
LockTimeOfFlight	Locks the time of flight of the TrajectoryPhase.
LockVelocity	Locks TrajectoryPhase cartesian velocity variables.
PutToFile	Convert the object state to FreeFlyer object xml and write to a file.
PutToString	Convert the object state to FreeFlyer object xml and return as a string.
ReferenceEquals	Returns 1 if the argument refers to the calling object and 0 otherwise.
RemoveAllNodes	Removes all nodes from the TrajectoryPhase's TrajectoryNodes array.
RemoveNode	Removes the node at the specified index in the TrajectoryPhase's TrajectoryNodes array.
ResampleNodes	Re-interpolates the TrajectoryPhase's nodes using new node spacing.
Restore	Restore an object's state from a previously saved state.
Reverse	Reverses the order of the TrajectoryPhase's TrajectoryNodes.
Save	Save the object's state so that it can be restored later.
SetCentralBody	Sets the TrajectoryPhase's central body. Note: once nodes have been added to the TrajectoryPhase.Nodes array, calling this method is not allowed.
SetControlVariableBounds	Set bounds for the TrajectoryPhase control variables associated with the passed region and indices.
SetEpochBounds	Set bounds for the TrajectoryPhase's epoch variable associated with the passed endpoint.
SetMassBounds	Set bounds for the TrajectoryPhase mass variable associated with the passed range.
SetPositionBounds	Set bounds for the TrajectoryPhase's cartesian position variables.
SetTimeOfFlightBounds	Sets bounds for the time of flight of the TrajectoryPhase.
SetVelocityBounds	Set bounds for the TrajectoryPhase's cartesian velocity variables.