core::PID Class Reference

#include <pid.h>

Public Member Functions
void	set_pid (double kP, double kI, double kD)
void	set_p (double kP)
void	set_i (double kI)
void	set_d (double kD)
void	set_tolerance (double tolerance)
void	set_i_zone (double i_zone)
double	p () const
double	i () const
double	d () const
double	tolerance () const
double	i_zone () const
void	set_i_limits (double i_min, double i_max)
void	set_output_limits (double minimum_output, double maximum_output)
double	dt () const
void	set_dt (double dt)
void	set_setpoint (double setpoint)
double	setpoint () const
bool	is_continuous () const
void	enable_continuous (double minimum_input=-1, double maximum_input=1)
void	disable_continuous ()
bool	at_setpoint () const
double	calculate (double measurement)
double	calculate (double setpoint, double measurement)
void	reset ()
void	reset_i ()

Detailed Description

Implements a PID controller with some additional features.

This class allows for setting PID gains, tolerance, integral zone, integral limits, output limits, and continuous mode for angle wrapping.

The PID formula is: output = kP * error + kI * integral(error) + kD * derivative(error)

Author

Ryan McGee, Jack Cammarata

Date

4/3/2020, 6/27/2025

Member Function Documentation

at_setpoint()

bool core::PID::at_setpoint ( ) const

inline

Checks if the measured value is at the setpoint within the tolerance.

Returns

True if the error is within the tolerance.

calculate() [1/2]

double core::PID::calculate ( double measurement )

inline

Calculates the PID output based on the current measurement.

Parameters

measurement

The current measurement value.

Returns

The calculated PID output.

calculate() [2/2]

double core::PID::calculate ( double setpoint, double measurement )

inline

Calculates the PID output based on a setpoint and current measurement.

Parameters

setpoint	The desired setpoint value.
measurement	The current measurement value.

Returns

The calculated PID output.

d()

double core::PID::d ( ) const

inline

Returns the derivative gain.

Returns

The derivative gain.

disable_continuous()

void core::PID::disable_continuous ( )

inline

Disables continuous mode.

dt()

double core::PID::dt ( ) const

inline

Returns the time period in seconds.

Returns

The time period in seconds.

enable_continuous()

void core::PID::enable_continuous ( double minimum_input = -1, double maximum_input = 1 )

inline

Enables continuous mode and sets the input range. This wraps the inputs, mostly useful for angles.

Parameters

minimum_input	The minimum input value (default -1).
maximum_input	The maximum input value (default 1).

i()

double core::PID::i ( ) const

inline

Returns the integral gain.

Returns

The integral gain.

i_zone()

double core::PID::i_zone ( ) const

inline

Returns the integral zone.

Returns

The integral zone value.

is_continuous()

bool core::PID::is_continuous ( ) const

inline

Checks if the PID controller is in continuous mode.

Returns

True if in continuous mode.

p()

double core::PID::p ( ) const

inline

Returns the proportional gain.

Returns

The proportional gain.

reset()

void core::PID::reset ( )

inline

Resets the PID controller.

reset_i()

void core::PID::reset_i ( )

inline

Resets the integral term only.

set_d()

void core::PID::set_d ( double kD )

inline

Sets the Derivative gain.

Parameters

kD	The derivative gain.

set_dt()

void core::PID::set_dt ( double dt )

inline

Sets the update time period in seconds.

Parameters

dt	The time period in seconds.

set_i()

void core::PID::set_i ( double kI )

inline

Sets the Integral gain.

Parameters

kI	The integral gain.

set_i_limits()

void core::PID::set_i_limits ( double i_min, double i_max )

inline

Sets limits on the effect of the integral term.

Parameters

i_min	The minimum value for the integral term.
i_max	The maximum value for the integral term.

set_i_zone()

void core::PID::set_i_zone ( double i_zone )

inline

Sets the integral zone. If the absolute error is less than this value, the integral term will accumulate. If the absolute error is greater than this value, the accumulated error will be reset to zero.

Parameters

i_zone

The integral zone value.

set_output_limits()

void core::PID::set_output_limits ( double minimum_output, double maximum_output )

inline

Sets the output limits, usually -12V to 12V for a motor.

Parameters

minimum_output	The minimum output value.
maximum_output	The maximum output value.

set_p()

void core::PID::set_p ( double kP )

inline

Sets the Proportional gain.

Parameters

kP	The proportional gain.

set_pid()

void core::PID::set_pid ( double kP, double kI, double kD )

inline

Sets the PID gains.

Parameters

kP	The proportional gain.
kI	The integral gain.
kD	The derivative gain.

set_setpoint()

void core::PID::set_setpoint ( double setpoint )

inline

Sets the setpoint.

Parameters

setpoint

The setpoint value.

set_tolerance()

void core::PID::set_tolerance ( double tolerance )

inline

Sets the tolerance for whether the setpoint is reached.

Parameters

tolerance

The tolerance value. If absolute error < tol then it's at the setpoint.

setpoint()

double core::PID::setpoint ( ) const

inline

Returns the current setpoint.

Returns

The setpoint value.

tolerance()

double core::PID::tolerance ( ) const

inline

Returns the tolerance.

Returns

The tolerance value.

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The documentation for this class was generated from the following file:

• math/controls/pid.h