Class PIDController

    • Constructor Summary

      Constructors 
      Constructor Description
      PIDController​(double Kp, double Ki, double Kd)
      Allocates a PIDController with the given constants for Kp, Ki, and Kd and a default period of 0.02 seconds.
      PIDController​(double Kp, double Ki, double Kd, double period)
      Allocates a PIDController with the given constants for Kp, Ki, and Kd.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean atSetpoint()
      Returns true if the error is within the tolerance of the setpoint.
      double calculate​(double measurement)
      Returns the next output of the PID controller.
      double calculate​(double measurement, double setpoint)
      Returns the next output of the PID controller.
      void close()  
      void disableContinuousInput()
      Disables continuous input.
      void enableContinuousInput​(double minimumInput, double maximumInput)
      Enables continuous input.
      double getD()
      Get the Differential coefficient.
      double getI()
      Get the Integral coefficient.
      double getP()
      Get the Proportional coefficient.
      double getPeriod()
      Returns the period of this controller.
      double getPositionError()
      Returns the difference between the setpoint and the measurement.
      double getSetpoint()
      Returns the current setpoint of the PIDController.
      double getVelocityError()
      Returns the velocity error.
      void initSendable​(SendableBuilder builder)
      Initializes this Sendable object.
      boolean isContinuousInputEnabled()
      Returns true if continuous input is enabled.
      void reset()
      Resets the previous error and the integral term.
      void setD​(double Kd)
      Sets the Differential coefficient of the PID controller gain.
      void setI​(double Ki)
      Sets the Integral coefficient of the PID controller gain.
      void setIntegratorRange​(double minimumIntegral, double maximumIntegral)
      Sets the minimum and maximum values for the integrator.
      void setP​(double Kp)
      Sets the Proportional coefficient of the PID controller gain.
      void setPID​(double Kp, double Ki, double Kd)
      Sets the PID Controller gain parameters.
      void setSetpoint​(double setpoint)
      Sets the setpoint for the PIDController.
      void setTolerance​(double positionTolerance)
      Sets the error which is considered tolerable for use with atSetpoint().
      void setTolerance​(double positionTolerance, double velocityTolerance)
      Sets the error which is considered tolerable for use with atSetpoint().
    • Constructor Detail

      • PIDController

        public PIDController​(double Kp,
                             double Ki,
                             double Kd)
        Allocates a PIDController with the given constants for Kp, Ki, and Kd and a default period of 0.02 seconds.
        Parameters:
        Kp - The proportional coefficient.
        Ki - The integral coefficient.
        Kd - The derivative coefficient.
      • PIDController

        public PIDController​(double Kp,
                             double Ki,
                             double Kd,
                             double period)
        Allocates a PIDController with the given constants for Kp, Ki, and Kd.
        Parameters:
        Kp - The proportional coefficient.
        Ki - The integral coefficient.
        Kd - The derivative coefficient.
        period - The period between controller updates in seconds.
    • Method Detail

      • setPID

        public void setPID​(double Kp,
                           double Ki,
                           double Kd)
        Sets the PID Controller gain parameters.

        Set the proportional, integral, and differential coefficients.

        Parameters:
        Kp - The proportional coefficient.
        Ki - The integral coefficient.
        Kd - The derivative coefficient.
      • setP

        public void setP​(double Kp)
        Sets the Proportional coefficient of the PID controller gain.
        Parameters:
        Kp - proportional coefficient
      • setI

        public void setI​(double Ki)
        Sets the Integral coefficient of the PID controller gain.
        Parameters:
        Ki - integral coefficient
      • setD

        public void setD​(double Kd)
        Sets the Differential coefficient of the PID controller gain.
        Parameters:
        Kd - differential coefficient
      • getP

        public double getP()
        Get the Proportional coefficient.
        Returns:
        proportional coefficient
      • getI

        public double getI()
        Get the Integral coefficient.
        Returns:
        integral coefficient
      • getD

        public double getD()
        Get the Differential coefficient.
        Returns:
        differential coefficient
      • getPeriod

        public double getPeriod()
        Returns the period of this controller.
        Returns:
        the period of the controller.
      • setSetpoint

        public void setSetpoint​(double setpoint)
        Sets the setpoint for the PIDController.
        Parameters:
        setpoint - The desired setpoint.
      • getSetpoint

        public double getSetpoint()
        Returns the current setpoint of the PIDController.
        Returns:
        The current setpoint.
      • atSetpoint

        public boolean atSetpoint()
        Returns true if the error is within the tolerance of the setpoint.

        This will return false until at least one input value has been computed.

        Returns:
        Whether the error is within the acceptable bounds.
      • enableContinuousInput

        public void enableContinuousInput​(double minimumInput,
                                          double maximumInput)
        Enables continuous input.

        Rather then using the max and min input range as constraints, it considers them to be the same point and automatically calculates the shortest route to the setpoint.

        Parameters:
        minimumInput - The minimum value expected from the input.
        maximumInput - The maximum value expected from the input.
      • disableContinuousInput

        public void disableContinuousInput()
        Disables continuous input.
      • isContinuousInputEnabled

        public boolean isContinuousInputEnabled()
        Returns true if continuous input is enabled.
      • setIntegratorRange

        public void setIntegratorRange​(double minimumIntegral,
                                       double maximumIntegral)
        Sets the minimum and maximum values for the integrator.

        When the cap is reached, the integrator value is added to the controller output rather than the integrator value times the integral gain.

        Parameters:
        minimumIntegral - The minimum value of the integrator.
        maximumIntegral - The maximum value of the integrator.
      • setTolerance

        public void setTolerance​(double positionTolerance)
        Sets the error which is considered tolerable for use with atSetpoint().
        Parameters:
        positionTolerance - Position error which is tolerable.
      • setTolerance

        public void setTolerance​(double positionTolerance,
                                 double velocityTolerance)
        Sets the error which is considered tolerable for use with atSetpoint().
        Parameters:
        positionTolerance - Position error which is tolerable.
        velocityTolerance - Velocity error which is tolerable.
      • getPositionError

        public double getPositionError()
        Returns the difference between the setpoint and the measurement.
        Returns:
        The error.
      • getVelocityError

        public double getVelocityError()
        Returns the velocity error.
      • calculate

        public double calculate​(double measurement,
                                double setpoint)
        Returns the next output of the PID controller.
        Parameters:
        measurement - The current measurement of the process variable.
        setpoint - The new setpoint of the controller.
      • calculate

        public double calculate​(double measurement)
        Returns the next output of the PID controller.
        Parameters:
        measurement - The current measurement of the process variable.
      • reset

        public void reset()
        Resets the previous error and the integral term.