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

java.lang.Object
org.wpilib.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 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.