Class ThrusterControlSoftware

Namespace

NominalSystems.Classes

Assembly

NominalSystems.Classes.dll

[Nominal] Defines the thruster controller software. This module takes a desired torque to control the spacecraft, and maps it to an array of thrusters.

---

public class ThrusterControlSoftware : Software

Inheritance

object

Simulation.Object

UniverseEvent

UniverseBehaviour

Software

ThrusterControlSoftware

Constructors

ThrusterControlSoftware()

Default constructor

protected ThrusterControlSoftware()

Fields

AngleErrorThreshold

[rad] Angular error at which thruster forces are scaled to not be super-saturated

[Unit(UnitType.RADIAN)]
public double AngleErrorThreshold

Field Value

double

ControlAxes_B

Array of the control unit axes

[Unit(UnitType.NONE)]
public Matrix3 ControlAxes_B

Field Value

Matrix3

In_BodyMassMsg

Vehicle configuration input message. Gets component's parent if null.

public MassMessage? In_BodyMassMsg

Field Value

MassMessage

In_CommandTorqueMsg

Commanded spacecraft external control torque message

public CommandTorqueMessage? In_CommandTorqueMsg

Field Value

CommandTorqueMessage

In_ThrusterArrayConfigMsg

Configuration of thrusters attached to the spacecraft

public ThrusterArrayConfigMessage? In_ThrusterArrayConfigMsg

Field Value

ThrusterArrayConfigMessage

Out_ThrustForceArrayMsg

Output thruster force commands for thruster array

public ThrustForceArrayMessage? Out_ThrustForceArrayMsg

Field Value

ThrustForceArrayMessage

SmallValue

[-] Specifies what is considered a small number

[Unit(UnitType.NONE)]
public double SmallValue

Field Value

double

ThrusterForceSign

Flag indicating if pos (+1) or negative (-1) thruster solutions are found

[Unit(UnitType.NONE)]
public int ThrusterForceSign

Field Value

int

TorqueAngleError

[rad] Angular error of the effector torque

[Unit(UnitType.RADIAN)]
public double TorqueAngleError

Field Value

double

UseSecondLoop

Flag indicating if the 2nd least squares fitting loop should be used

public bool UseSecondLoop

Field Value

bool

Methods

ComputeTorqueAngleError(Matrix, Vector3, int, Vector, double[])

Determine the angle between the desired torque vector and the actual torque vector.

protected double ComputeTorqueAngleError(Matrix torque, Vector3 bLr_B, int numForces, Vector force, double[] forceMag)

Parameters

torque Matrix

bLr_B Vector3

numForces int

force Vector

forceMag double[]

Returns

double

FindMinimumNormForce(Matrix, Vector3, int)

Use a least square inverse to determine the smallest set of thruster forces that yield the desired torque vector.
Note that this routine does not constrain yet the forces to be either positive or negative

protected Vector FindMinimumNormForce(Matrix D, Vector3 Lr_B_Bar, int NumForces)

Parameters

D Matrix

Lr_B_Bar Vector3

NumForces int

Returns

Vector

Initialise()

This method is called whenever some key parameters are changed and any new local variables are required to be recalculated. This can be called by the software chains if a configuration of some values are updated.

public override void Initialise()

OnBegin(double)

Called when the object is beginning ticking for the first time. This is when the simulation calls the very first tick and will run before the update call.

protected override void OnBegin(double time)

Parameters

time double

[s] Current time of the simulation before the tick

OnCreate()

Called when the object is created from the controller and has been attached to the parent object. By this point, it has been registered to the simulation and will run after the constructor.

protected override void OnCreate()

OnLoad(double)

Called after all of the data has been loaded from a save state on this object. This enables any post-load operations to be performed and extra data to be loaded from the metadata.

protected override void OnLoad(double time)

Parameters

time double

[s] The current clock time of the simulation

OnUpdate(double, double)

Called when the object should update from the simulation tick. This will take in a time and a step, where the time is the time of the clock before updating the object.

protected override void OnUpdate(double time, double step)

Parameters

time double

[s] Current time of the simulation before the update

step double

[s] The time-step to update during this tick

SubtractMin(Vector, int)

Take a stack of force values find the smallest value, and subtract if from all force values. Here the smallest values will become zero, while other forces increase.
Assumption: Thrusters are aligned such that if all thrusters are firing, then no torque or force is applied.
This ensures only positive force values are computed.

protected Vector SubtractMin(Vector F, int size)

Parameters

F Vector

size int

Returns

Vector