Package edu.wpi.first.math.controller

Class ImplicitModelFollower<States extends Num,Inputs extends Num,Outputs extends Num>

java.lang.Object

edu.wpi.first.math.controller.ImplicitModelFollower<States,Inputs,Outputs>

Type Parameters:

States - Number of states.

Inputs - Number of inputs.

Outputs - Number of outputs.

public class ImplicitModelFollower<States extends Num,Inputs extends Num,Outputs extends Num>
extends Object

Contains the controller coefficients and logic for an implicit model follower.

Implicit model following lets us design a feedback controller that erases the dynamics of our system and makes it behave like some other system. This can be used to make a drivetrain more controllable during teleop driving by making it behave like a slower or more benign drivetrain.

For more on the underlying math, read appendix B.3 in https://file.tavsys.net/control/controls-engineering-in-frc.pdf.

Constructor Summary

Constructors

Constructor	Description
ImplicitModelFollower(Matrix<States,States> A, Matrix<States,Inputs> B, Matrix<States,States> Aref, Matrix<States,Inputs> Bref)	Constructs a controller with the given coefficients and plant.
ImplicitModelFollower(LinearSystem<States,Inputs,Outputs> plant, LinearSystem<States,Inputs,Outputs> plantRef)	Constructs a controller with the given coefficients and plant.

Method Summary

Modifier and Type	Method	Description
Matrix<Inputs,N1>	calculate(Matrix<States,N1> x, Matrix<Inputs,N1> u)	Returns the next output of the controller.
Matrix<Inputs,N1>	getU()	Returns the control input vector u.
double	getU(int i)	Returns an element of the control input vector u.
final void	reset()	Resets the controller.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

ImplicitModelFollower

public ImplicitModelFollower(LinearSystem<States,Inputs,Outputs> plant,
 LinearSystem<States,Inputs,Outputs> plantRef)

Constructs a controller with the given coefficients and plant.

Parameters:

plant - The plant being controlled.

plantRef - The plant whose dynamics should be followed.

ImplicitModelFollower

public ImplicitModelFollower(Matrix<States,States> A,
 Matrix<States,Inputs> B,
 Matrix<States,States> Aref,
 Matrix<States,Inputs> Bref)

Constructs a controller with the given coefficients and plant.

Parameters:

A - Continuous system matrix of the plant being controlled.

B - Continuous input matrix of the plant being controlled.

Aref - Continuous system matrix whose dynamics should be followed.

Bref - Continuous input matrix whose dynamics should be followed.

Method Details

getU

public Matrix<Inputs,N1> getU()

Returns the control input vector u.

Returns:

The control input.

getU

public double getU(int i)

Returns an element of the control input vector u.

Parameters:

i - Row of u.

Returns:

The row of the control input vector.

reset

public final void reset()

Resets the controller.

calculate

public Matrix<Inputs,N1> calculate(Matrix<States,N1> x,
 Matrix<Inputs,N1> u)

Returns the next output of the controller.

Parameters:

x - The current state x.

u - The current input for the original model.

Returns:

The next controller output.