FormationFlying Module

Directory List

Analysis Collision Control
Coord DataStructures Demos/Collision
Demos/Control Demos/Coord Demos/Dynamics
Demos/Eccentric Demos/Guidance Demos/LP
Demos/SafeGuidance Demos/Visual Dynamics
EccDynamics Guidance IntegratedSim
LP SafeGuidance Transformation
Utility Visual


Analysis

Analyze delta-V maneuver sequences with time between burns
Plot the trajectory that will result from a planned maneuver.
Compare closed form Hills equations with other methods of propagation.
Simulation routine for testing DFF guidance and control laws.
Compute the total delta-v assoc. w/ several types of reconfigurations.
Find the standard deviation of along-track drift per orbit due to rel nav errors.
Compare two methods of computing the relative motion in an eccentric orbit.
Plot the results from "FFMaintenanceSim".
Formation flying maintenance simulation.
Returns data associated with various test runs for "FFMaintenanceSim".
Find the drift rate term given a probability
Compare the delta-v and trajectory for two methods of relative orbit control.
Compute max. navigation error that maintains the specified performance.
Test the FFEccLinOrb function.
Test the LPEccentric function.
Test the LPEccentric function.
Test the LPEccentricGVE function.

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Collision

Coarse collision probability estimate
Calculates the probability of collision given two ellipsoid sets.
Calculates the probability of collision given two ellipsoids using volume relations.
Sample data for collision algorithm initialization.
Collision monitoring algorithm for maneuvering spacecraft.
Runs the collision monitoring algorithm.
Monte-Carlo analysis of collision probability
Runs the collision monitoring algorithm for n maneuvering spacecraft.
Transformation matrix for relative conjunction geometry.
Distance from a point to the edge of an ellipsoid.
2D elliptical patch, with axes a along x and b along y
Function finds the propagated state uncertainty ellipsoid
Calculate vertices for an ellipsoid.
Generate a time vector evenly spaced over true anomaly
Finds the polynomial roots using Laguerre's method.
Computes the minimum distance between two ellipsoids.
Plot collision ellipsoids in 3D
Predict collisions given a new state measurement.
Relative disturbances for use with a relative state.
Update computed fields in the collision data structure fields.
Plot collision monitoring ellipsoids.
Worst-case differential accelerations for spacecraft in formation.

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Control

Computes the delta-v sequence for a relative orbit maneuver.
Computes a delta-v sequence for a relative orbit maneuver in a circular orbit
Computes the delta-v's required for an in-plane maneuver.
Iterative impulsive maneuver delta-V
Demonstrates control of a large formation of satellites.
Generate an LQG controller for linearized relative orbit dynamics.
Compute a constant gain feedback controller for relative orbital motion.
Computes the delta-v's and half-orbit delays for an in-plane maneuver.
Computes the delta-v's required for an out-of-plane maneuver.

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Coord

Add one set of geometric goals to the other.
Computes the desired Hills-to-Body frame quaternion for a thruster firing.
Compute the desired phase on the circle from the desired phase on the ellipse.
Compute the desired phase on the ellipse from the desired phase on the circle.
Get Hills transformation matrices
Generate LVLH transformation matrices
Initialize formation orbital states from geometric goals
Check whether the supplied data structure is for circular geometry or not.
Check whether the supplied data structure is for eccentric geometry or not.
Leader-follower Hills state
Projected circle state in Hills frame
Calculates orbital elements for projected circular formation.
Calculates orbital elements for an in-line formation.
Generate the quaternion that transforms from the ECI to the Frenet frame.
Compute the Hills-to-Body quaternion
Rotate a geometric state to the circular phase angle phi.
Scale a relative state represented by a geometric goal set. This
Subtract one set of geometric goals from the other.
Extract the geometry data from the team goals data structure
Computes body vectors to align with velocity and nadir for a thruster firing.

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DataStructures

Initialize a burn data structure.
Command data structure for external commands supplied to DFF system.
Initialize a constraints data structure.
Initialize a cost estimate data structure.
Initialize a delta-v command data structure.
Initialize an eccentric geometry data structure.
Initialize a team goals data structure (for eccentric geometries)
Initialize a geometry data structure.
The ISL message data structure format.
Initialize a maneuver data structure.
Initialize an orientation command data structure.
Initialize a planning parameters data structure.
Initialize a state data structure.
Initialize a team goals data structure.
Initialize a team data structure.
Initialize a window data structure.

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Demos/Collision

Extension of AssignmentDemo to include collision monitoring.
AssignmentResults.matSaved output from AssignmentDemo for collision monitoring demo.
Coarse probability demo
Simulation for testing the collision monitoring algorithms.
Collision monitoring demo.
Collision monitoring demo: compare CollisionSurvey and coarse methods.
Ellipsoid minimum distance demo
Collision monitoring demo for highly eccentric reconfiguration.
SampleMvr.matSaved maneuver data with 4 burns for collision demos
Set membership probability demo. Verify shape of function.

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Demos/Control

Analyze the performance of relative orbit control in eccentric orbits
Demonstrate the use of FFMaintenanceSim to analyze disturbance effects.
Demonstrate LQG control of relative motion in an eccentric orbit
Relative orbit control using LQG

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Demos/Coord

Demonstrate the RotateState function
Two orbits are initialized with a small inclination difference. The orbits

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Demos/Dynamics

Simulate relative motion in a HEO orbit with solar pressure disturbance
Compares the relative motion predicted by propagation of the discrete state-space system with the motion predicted by Hills equations.
Relative simulation with accelerations to produce an offset in leader-follower frame.

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Demos/Eccentric

Demonstrate an example relative trajectory with an eccentric reference orbit
Demonstrate the different solutions found by the optimal assignment method and the privileged assignment method, in an eccentric orbit.
Demonstrate how relative motion changes when the same relative state is initialized at different true anomalies.
Compare discrete propagation with continuous solution.
Compute several reconfiguation maneuvers of varying duration for an elliptical reference orbit.

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Demos/Guidance

Demonstrate the different solutions found by the optimal assignment method and the privileged assignment method.
Run a formation flying simulation with "DFFSim".
Demonstrate rendezvous control with PD or LQ

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Demos/LP

Examine the "convergence rate" for an impulsive LP solution
Analyze the performance of the LPEccentric algorithm.

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Demos/SafeGuidance

Demonstrate the safe ellipse for safe relative orbit guidance
Demonstrate the performance of Safe Guidance Mode

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Demos/Visual

Visualization of eccentric relative orbits

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Dynamics

Compute a trajectory from discretized Hills equations
Integrate two neighboring orbits, with applied relative accelerations
Closed form solution of relative orbital motion using Hills equations.
Continuous-time linear model of Hills equations in the Hills frame.
Convert short arc measurements to an approximate Hill's state.

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EccDynamics

Compute the second derivative of x with respect to true anomaly.
Compute the second derivative of y with respect to true anomaly.
Compute the second derivative of z with respect to true anomaly.
Compute the first derivative of x with respect to true anomaly.
Compute the first derivative of y with respect to true anomaly.
Compute the slope of an ellipse, dy/dx, at a particular true anomaly.
Compute the second derivative of y with respect to x on an ellipse.
Compute the first derivative of z with respect to true anomaly.
Computes the relative state trajectory in an eccentric reference orbit.
Compute integration constant dH for homogeneous solution to LTV diff eqs
Compute velocities for periodic motion in an eccentric orbit
Computes the relative state trajectory in an eccentric reference orbit.
Compute integration constants and initial state given the geometric goals.
Compute the H term for the homogeneous solution to LTV diff eqs
Integration constants for eccentric relative motion
Compute Hills frame state given initial state, true anomaly, and eccentricity
Linearized relative motion in an eccentric reference orbit
Compute Hills frame state at nu given integ. constants and eccentricity.
Compute the state-transition matrix, R, given the eccentricity and true anomaly.
Compute extreme x-values and associated true anomalies for given relative motion.
Compute extreme y-values and associated true anomalies for given relative motion.
Compute extreme z-values and associated true anomalies for given relative motion.

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Guidance

Autonomously update geometric goals
Given the team goals, determines the starting row (a) and ending row (b)
Given a set of geometric goals for the cluster, with corresponding target
Estimate the (weighted) cost to achieve all specified unique target states.
Estimate the weighted cost to achieve all specified unique target states
Generate a Team Goals data structure given the formation type and size.
Geometric goals for a hexahedron
Goals for tetrahedron geometry in an eccentric orbit.
Find the order of columns in a square matrix which minimizes
Generate a Team Goals data structure given the formation type and size.
Given the team goals, initialize the cost matrix "f" with the right size.
Determine whether two geometric goal sets are duplicates or not.
Determine the nearest along-track offset for a trajectory that is safe.
Compute the optimal configuration for a group of objects.
Generate the geometric goals for a cluster in a projected circular formation.
Fill in a single column of the cost matrix.
Assign target states to satellites using the privileged assignment method.
Given an initial set of relative spacecraft IDs, examine the constraints
Set up the parameters for the assignment problem given the team goals struct.
Sort the team goals with fixed states listed before variable states.

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IntegratedSim

Thruster pulsewidth model for DFF.
Ideal actuator
Post simulation analysis of alignment.
Post-simulation message analysis for DFF.
Test each DFF Module individually, in batch mode.
Command list for the following scenario.
Command list for testing autonomous formation and bridging of teams.
Command list for demonstrating the achievement of cluster goals
Command list for monitoring a collision. Same as ProjCircCommandList
Command list for collision monitoring demo scenario.
Command list for Collision Detection Simulation
A specific command list is loaded for each simulation run.
Command list for the testing the controller. Two spacecraft initialized
Command list for achieving a tetrahedron formation in an eccentric orbit
Command list for the main demo. Involves autonomous team formation
Command list for achieving a dual-plane projected circle,
Command list for implementing a simple maneuver with 2 spacecraft.
Command list for exercising the team management functionality.
Command list for testing the proper function of the ADCS.
Command list for the testing the controller. Two spacecraft initialized
Command list for Collision Detection Simulation
Command list for the testing the controller. Two spacecraft initialized
Command list for testing the functionality of the Team Management agent.
Generate a reference quaternion for a variety of targets. There
The executive function that initializes and runs the DFF software modules.
Right-hand-side of the spacecraft dynamic equations for the DFF system.
DFF simulation status GUI.
Initialize and run a multiple spacecraft simulation with the DFF software.
ClusterGoalsTeamOrg.matExample cluster goals data
Generate a data structure for fuel tank info.
Load the dictionary of parameters that may be uploaded to the DFF system.
Load the dictionary of known software commands for the DFF system.
Obtain the specified set of fixed spacecraft parameters (for DFF system).
Load the dictionary of telemetry data to be gathered for the DFF system.
Define the simulation data structure for the following scenario.
Team autonomous formation simulation data structure.
Cluster goals demo simulation data structure.
ProjCircSimStruct with a new command list to run collision survey.
Collision detection simulation data structure.
ProjCircSimStruct with a new command list to run collision survey.
Set up the data structure for a DFF simulation. All inputs are optional.
Set up the data structure for testing the controller.
Eccentric tetrahedron simulation data structure.
Define the simulation data structure for the main demo
Projected circle reconfiguration simulation data structure.
Set up the data structure for testing the controller.
Set up the data structure for a Team Management demonstration of the DFF system.
TeamOrgDemo.matExample data with 5 satellites and 2 teams
Attitude control test data structure
Set up a DFF simulation data structure to demonstrate collision detection
Set up the data structure for testing the controller.
Set up the data structure for testing both orbit and attitude control.
Team management simulation data structure
State sensor. Gives the ideal states of the system.
DFF attitude control routine.
The attitude coordination component of the decentralized framework.
The attitude management component of the decentralized framework.
DFF attitude maneuver planning
The Collision Avoidance module for the DFF system.
The Collision monitoring component for the decentralized framework
Receive ground commands and route them to the appropriate module(s).
The decentralized control law.
The coordinate transformation element of the software.
The delta-v management component of the control software.
The decentralized guidance law.
The ISL management software for the decentralized framework.
Template for DFF software module. Describe the basic functionality here.
The parameter database for the decentralized formation flying framework.
DFF relative navigation
The team management software for the decentralized satellite framework.

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LP

Computes the thrust trajectory to go from an initial state x0
Determine the target state on the desired trajectory that gives the minimum
Computes the thrust trajectory to go from an initial state x0
Computes the thrust trajectory to go from an initial state x0 to a
Determine the target state on the desired trajectory that gives the minimum

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SafeGuidance

Compute attributes of along-track motion from relative state vector
Animate the evolution of the desired "safe ellipse" with the position
Compute a safe 2x1 relative in-plane ellipse.
Compute the DV to achieve a min. cross-track dist. at along-track crossing.
Generate a stacked bar chart showing delta-v directions over time
Compute a delta-v that will change the current relative trajectory to a
Closed form solution of relative orbital motion using Hills equations.
The Nominal Safe Guidance method.
Generate a 3D plot of a relative trajectory.
Compute delta-v required to reach a target position, given pos. and vel.
Compute the Hills-frame state associated with a relative ellipse.
Compute the SLO-frame state associated with a relative ellipse.
Compute the radial oscillation of the relative motion using Hills eqns.
Restrict the in-plane and cross-track components of the delta-v
Compute the "safe ellipse" parameters from relative SLO-frame pos & vel
Compute the relative SLO-frame position and velocity that corresponds to
The Safe Guidance Mode.
Find index values for separation, nominal and cross-track burns.
Tunable parameters for Safe Guidance and Collison Detection algorithms
Relative dynamic simulation for two LEO satellites with safe guidance.
Returns input data for various test cases for SafeGuidanceSim
Plot select results from a simulation
The Separation Guidance method.
Compute the maximum value of yR

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Transformation

Compute a Hills state from a relative ECI state
Compute standard differential elements from Alfriend differential elements.
Compute Alfriend differential elements from standard differential elements.
Reconstructs the geometric goals from the element differences.
Computes the Hills frame state from orbital element differences and
Compute the relative state in Hills frame given two ECI state vectors.
Compute relative LVLH state from a reference ECI state and ECI state
Computes mean orbital elements from reference ECI position and velocity
Convert element differences to eccentric geometric goals.
Convert element differences to Hills frame coordinates in an eccentric orbit.
Compute geometric goals given Frenet frame state and orbit info
Compute Hills frame state (time-domain) given geometric goals and orbit info
Compute element differences from Hills frame state and ref. elements
Compute geometric goals given Hills frame state and orbit info
Rotate the Frenet frame state to the Hills frame, where x is radial
Convert a circular geometry structure to an eccentric geometry structure.
Convert an eccentric geometry structure to a circular geometry structure.
Computes the desired orbital element differences, given the formation flying
Compute a Hills state from geometric goals
Computes the Hills orbital element differences
Given the reference state in ECI, converts a Hills frame state to ECI.
Rotate the Hills frame state to the Frenet frame, where x is along-track
Convert Hills state to geometric goals
Converts a state vector from the Hills to the LVLH coordinate frame.
Given the reference state in ECI, converts an LVLH frame state to ECI.
Converts a state vector from the LVLH to the Hills coordinate frame.
Transforms mean orbital elements to osculating orbital elements.
Transforms mean orbital elements to osculating orbital elements.
Transforms osculating orbital elements to mean orbital elements.
Transform geometric goals to hills-frame coordinates.

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Utility

Build a "maneuver" data structure from acceleration and time vectors.
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Find the size in bytes of a piece of data.
Compute the future true anomaly (unwrapped) at the specified number of orbits
Compute the 5 points of a regular tetrahedron, the surface area and volume.
Converts a Julian Date to seconds since 00:00:00 GMT, Jan. 1, 1970.
Compute a 3xN acceleration vector from a "maneuver" data structure.
Convert mean anomaly to true latitude.
Compute a vector of maneuver durations from time window data
Newton Raphson solver.
Convert a relative state from the nu-domain to the time-domain.
Compute the time-derivative of the true anomaly.
Generate an orbit by propagating Keplerian elements with impulsive delta-vs.
Converts seconds since 00:00:00 GMT, Jan. 1, 1970 to a Julian date.
Compute the 4 points of a regular tetrahedron, the surface area and volume.
Convert a relative state from the time-domain to the nu-domain.
Computes the time in seconds until the latitude "theta2" is reached from the

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Visual

CascadingTetrahedron.fd.matCascading tetrahedron saved formation design file.
Visualize the cost to achieve each target state on the trajectory.
Display Plugin for the Formation Design GUI.
Interactively analyze the shape of a relative trajectory in an eccentric reference orbit.
Compute the shape of the relative motion in the orbital plane.
Formation Design GUI.
Geometry Plugin for the Formation Design GUI.
Plot the trajectory in Hills frame and show the x-z, x-y projections.
MultiProjCirc.fd.matMulti-projected circle saved formation design file.
Orbit Data Plugin for the Formation Design GUI.
Relative State Plugin for the Formation Design GUI.
Satellite Plugin for the Formation Design GUI.
Graphically show the hierarchy of teams.
Assign a hierarchical level to each team in the array.
Team Plugin for the Formation Design GUI.
View the 3-D trajectory of a formation in Hills frame.
View the geometry created by a formation of spacecraft
Animation the relative motion in Hills frame.
View the relative motion for geometric goals
Animate a satellite's relative trajectory in the inertial frame.

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