robot_controllers::PID Class Reference

#include <pid.h>

List of all members.

Public Member Functions
bool	init (const ros::NodeHandle &nh)
	initialize gain settings from ROS parameter values
	PID (double p, double i, double d, double i_max, double i_min)
	Constructor.
	PID ()
	Constructor. Starts all gains and limits at zero.
void	reset ()
	Reset integral wind-up term.
double	update (double error, double dt)
	Run PID calculation and return control result.
double	update (double error, double error_dot, double dt)
	Run PID calculation and return control result.
Protected Member Functions
bool	checkGains ()
	Checks and fixes gain settings.
Protected Attributes
double	d_gain_
	derivative gain
double	error_last_
	Last error value, used for calculating error_dot when not provided.
double	i_gain_
	integral gain
double	i_max_
	integral gain min and max limits
double	i_min_
double	i_term_
	integral wind-up term
double	p_gain_
	proportial gain

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Detailed Description

Definition at line 45 of file pid.h.

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Constructor & Destructor Documentation

robot_controllers::PID::PID	(	double	p,
		double	i,
		double	d,
		double	i_max,
		double	i_min
	)

Constructor.

Parameters:

p	proportional gain
i	integral gain
d	derivative gain
i_max	integral wind-up max value
i_min	integral wind-up min value

Definition at line 47 of file pid.cpp.

robot_controllers::PID::PID

(

)

Constructor. Starts all gains and limits at zero.

Definition at line 58 of file pid.cpp.

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Member Function Documentation

bool robot_controllers::PID::checkGains

(

)

[protected]

Checks and fixes gain settings.

Returns:

true is gains are ok, false if gains are invalid

Definition at line 92 of file pid.cpp.

bool robot_controllers::PID::init

(

const ros::NodeHandle &

nh

)

initialize gain settings from ROS parameter values

Definition at line 68 of file pid.cpp.

void robot_controllers::PID::reset

(

)

Reset integral wind-up term.

Definition at line 140 of file pid.cpp.

double robot_controllers::PID::update	(	double	error,
		double	dt
	)

Run PID calculation and return control result.

Parameters:

error	error term (goal-actual)
dt	timestep used for calculating derivative term and integral windup

Returns:

calculated PID command

PID derivate term is calculated from change in error value and dt

Definition at line 146 of file pid.cpp.

double robot_controllers::PID::update	(	double	error,
		double	error_dot,
		double	dt
	)

Run PID calculation and return control result.

Parameters:

error	error term (goal-actual)
error_dot	value that is used for derivative term calculation
dt	timestep used for integral windup

Returns:

calculated PID command

Definition at line 164 of file pid.cpp.

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Member Data Documentation

double robot_controllers::PID::d_gain_ [protected]

derivative gain

Definition at line 99 of file pid.h.

double robot_controllers::PID::error_last_ [protected]

Last error value, used for calculating error_dot when not provided.

Definition at line 107 of file pid.h.

double robot_controllers::PID::i_gain_ [protected]

integral gain

Definition at line 97 of file pid.h.

double robot_controllers::PID::i_max_ [protected]

integral gain min and max limits

Definition at line 101 of file pid.h.

double robot_controllers::PID::i_min_ [protected]

Definition at line 101 of file pid.h.

double robot_controllers::PID::i_term_ [protected]

integral wind-up term

Definition at line 104 of file pid.h.

double robot_controllers::PID::p_gain_ [protected]

proportial gain

Definition at line 95 of file pid.h.

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

• pid.h
• pid.cpp