light::PID Class Reference

Discrete PID controller with rich exit-condition support. More...

#include <pid.hpp>

Classes
struct	Constants
	PID gain constants. More...
struct	exit_condition_
	Exit condition timing and thresholds. More...

Public Member Functions
	PID ()
	Default constructor.
	PID (double p, double i=0, double d=0, double start_i=0, std::string name="")
	Constructor with constants.
void	constants_set (double p, double i=0, double d=0, double p_start_i=0)
	Set constants for PID.
void	exit_condition_set (int p_small_exit_time, double p_small_error, int p_big_exit_time=0, double p_big_error=0, int p_velocity_exit_time=0, int p_mA_timeout=0)
	Set's constants for exit conditions.
void	target_set (double input)
	Sets PID target.
double	compute (double current)
	Computes PID.
double	compute_error (double err, double current)
	Computes PID, but you compute the error yourself.
double	target_get ()
	Returns target value.
Constants	constants_get ()
	Returns constants.
bool	constants_set_check ()
	Returns true if PID constants are set, returns false if they're all 0.
void	variables_reset ()
	Resets all variables to 0.
void	velocity_sensor_secondary_set (double secondary_sensor)
	Updates a secondary sensor for velocity exiting.
double	velocity_sensor_secondary_get ()
	Returns the updated secondary sensor for velocity exiting.
void	velocity_sensor_secondary_toggle_set (bool toggle)
	Boolean for if the secondary sensor will be updated or not.
bool	velocity_sensor_secondary_toggle_get ()
	Returns the boolean for if the secondary sensor will be updated or not.
void	velocity_sensor_main_exit_set (double zero)
	Sets the threshold that the main sensor will return 0 velocity within.
double	velocity_sensor_main_exit_get ()
	Returns the threshold that the main sensor will return 0 velocity within.
void	velocity_sensor_secondary_exit_set (double zero)
	Sets the threshold that the secondary sensor will return 0 velocity within.
double	velocity_sensor_secondary_exit_get ()
	Returns the threshold that the secondary sensor will return 0 velocity within.
light::exit_output	exit_condition (bool print=false)
	Iterative exit condition for PID.
light::exit_output	exit_condition (pros::Motor sensor, bool print=false)
	Iterative exit condition for PID.
light::exit_output	exit_condition (std::vector< pros::Motor > sensor, bool print=false)
	Iterative exit condition for PID.
light::exit_output	exit_condition (pros::MotorGroup sensor, bool print=false)
	Iterative exit condition for PID.
void	name_set (std::string name)
	Sets the name of the PID that prints during exit conditions.
std::string	name_get ()
	Returns the name of the PID that prints during exit conditions.
void	i_reset_toggle (bool toggle)
	Enables / disables i resetting when sgn of error changes.
bool	i_reset_get ()
	Returns if i will reset when sgn of error changes.
void	timers_reset ()
	Resets all timers for exit conditions.

Public Attributes
Constants	constants
	Active PID gain constants (read/write).
exit_condition_	exit
	Active exit-condition thresholds (read/write).
Live PID state
Updated each call to compute() / compute_error().
double	output = 0.0
	Last computed control output.
double	cur = 0.0
	Last sensor value seen.
double	error = 0.0
	Current error (target − cur).
double	target = 0.0
	Current target.
double	prev_error = 0.0
	Previous-cycle error.
double	prev_current = 0.0
	Previous-cycle sensor value.
double	integral = 0.0
	Accumulated integral term.
double	derivative = 0.0
	Last derivative term.
long	time = 0
	Timestamp of last compute (ms).
long	prev_time = 0
	Timestamp of previous compute (ms).

Detailed Description

Discrete PID controller with rich exit-condition support.

Configure once via the constructor or constants_set(), then call compute() each cycle with the latest sensor reading. Use exit_condition() to detect when the controller has settled.

Definition at line 30 of file pid.hpp.

Constructor & Destructor Documentation

PID() [1/2]

light::PID::PID

(

)

Default constructor.

PID() [2/2]

light::PID::PID	(	double	p,
		double	i = 0,
		double	d = 0,
		double	start_i = 0,
		std::string	name = ""
	)

Constructor with constants.

Parameters

p	kP
i	ki
d	kD
p_start_i	error value that i starts within
name	std::string of name that prints

Member Function Documentation

compute()

double light::PID::compute

(

double

current

)

Computes PID.

Parameters

current

current sensor value

compute_error()

double light::PID::compute_error	(	double	err,
		double	current
	)

Computes PID, but you compute the error yourself.

Current is only used here for calculative derivative to solve derivative kick.

Parameters

err	error for the PID, you need to calculate this yourself
current	current sensor value

constants_get()

Constants light::PID::constants_get

(

)

Returns constants.

constants_set()

void light::PID::constants_set	(	double	p,
		double	i = 0,
		double	d = 0,
		double	p_start_i = 0
	)

Set constants for PID.

Parameters

p	kP
i	ki
d	kD
p_start_i	error value that i starts within

constants_set_check()

bool light::PID::constants_set_check

(

)

Returns true if PID constants are set, returns false if they're all 0.

exit_condition() [1/4]

light::exit_output light::PID::exit_condition

(

bool

print = false

)

Iterative exit condition for PID.

Parameters

print

= false if true, prints when complete

exit_condition() [2/4]

light::exit_output light::PID::exit_condition	(	pros::Motor	sensor,
		bool	print = false
	)

Iterative exit condition for PID.

Parameters

sensor	a pros motor on your mechanism
print	= false if true, prints when complete

exit_condition() [3/4]

light::exit_output light::PID::exit_condition	(	pros::MotorGroup	sensor,
		bool	print = false
	)

Iterative exit condition for PID.

Parameters

sensor	pros motor group on your mechanism
print	= false if true, prints when complete

exit_condition() [4/4]

light::exit_output light::PID::exit_condition	(	std::vector< pros::Motor >	sensor,
		bool	print = false
	)

Iterative exit condition for PID.

Parameters

sensor	pros motors on your mechanism
print	= false if true, prints when complete

exit_condition_set()

void light::PID::exit_condition_set	(	int	p_small_exit_time,
		double	p_small_error,
		int	p_big_exit_time = 0,
		double	p_big_error = 0,
		int	p_velocity_exit_time = 0,
		int	p_mA_timeout = 0
	)

Set's constants for exit conditions.

Parameters

p_small_exit_time	sets small_exit_time, timer for to exit within smalL_error
p_small_error	sets smalL_error, timer will start when error is within this
p_big_exit_time	sets big_exit_time, timer for to exit within big_error
p_big_error	sets big_error, timer will start when error is within this
p_velocity_exit_time	sets velocity_exit_time, timer will start when velocity is 0

i_reset_get()

bool light::PID::i_reset_get

(

)

Returns if i will reset when sgn of error changes.

True resets, false doesn't.

i_reset_toggle()

void light::PID::i_reset_toggle

(

bool

toggle

)

Enables / disables i resetting when sgn of error changes.

True resets, false doesn't.

Parameters

toggle

true resets, false doesn't

name_get()

std::string light::PID::name_get

(

)

Returns the name of the PID that prints during exit conditions.

name_set()

void light::PID::name_set

(

std::string

name

)

Sets the name of the PID that prints during exit conditions.

Parameters

name	the name of the mechanism for printing

target_get()

double light::PID::target_get

(

)

Returns target value.

target_set()

void light::PID::target_set

(

double

input

)

Sets PID target.

Parameters

target

new target for PID

timers_reset()

void light::PID::timers_reset

(

)

Resets all timers for exit conditions.

variables_reset()

void light::PID::variables_reset

(

)

Resets all variables to 0.

This does not reset constants.

velocity_sensor_main_exit_get()

double light::PID::velocity_sensor_main_exit_get

(

)

Returns the threshold that the main sensor will return 0 velocity within.

velocity_sensor_main_exit_set()

void light::PID::velocity_sensor_main_exit_set

(

double

zero

)

Sets the threshold that the main sensor will return 0 velocity within.

Parameters

zero	a small double

velocity_sensor_secondary_exit_get()

double light::PID::velocity_sensor_secondary_exit_get

(

)

Returns the threshold that the secondary sensor will return 0 velocity within.

velocity_sensor_secondary_exit_set()

void light::PID::velocity_sensor_secondary_exit_set

(

double

zero

)

Sets the threshold that the secondary sensor will return 0 velocity within.

Parameters

zero	a small double

velocity_sensor_secondary_get()

double light::PID::velocity_sensor_secondary_get

(

)

Returns the updated secondary sensor for velocity exiting.

velocity_sensor_secondary_set()

void light::PID::velocity_sensor_secondary_set

(

double

secondary_sensor

)

Updates a secondary sensor for velocity exiting.

Ideal use is IMU during normal drive motions.

Parameters

secondary_sensor

secondary sensor value

velocity_sensor_secondary_toggle_get()

bool light::PID::velocity_sensor_secondary_toggle_get

(

)

Returns the boolean for if the secondary sensor will be updated or not.

True uses this sensor, false does not.

velocity_sensor_secondary_toggle_set()

void light::PID::velocity_sensor_secondary_toggle_set

(

bool

toggle

)

Boolean for if the secondary sensor will be updated or not.

True uses this sensor, false does not.

Parameters

toggle

true uses this sensor, false does not

Member Data Documentation

constants

Constants light::PID::constants

Active PID gain constants (read/write).

Definition at line 154 of file pid.hpp.

cur

double light::PID::cur = 0.0

Last sensor value seen.

Definition at line 290 of file pid.hpp.

derivative

double light::PID::derivative = 0.0

Last derivative term.

Definition at line 296 of file pid.hpp.

error

double light::PID::error = 0.0

Current error (target − cur).

Definition at line 291 of file pid.hpp.

exit

exit_condition_ light::PID::exit

Active exit-condition thresholds (read/write).

Definition at line 157 of file pid.hpp.

integral

double light::PID::integral = 0.0

Accumulated integral term.

Definition at line 295 of file pid.hpp.

output

double light::PID::output = 0.0

Last computed control output.

Definition at line 289 of file pid.hpp.

prev_current

double light::PID::prev_current = 0.0

Previous-cycle sensor value.

Definition at line 294 of file pid.hpp.

prev_error

double light::PID::prev_error = 0.0

Previous-cycle error.

Definition at line 293 of file pid.hpp.

prev_time

long light::PID::prev_time = 0

Timestamp of previous compute (ms).

Definition at line 298 of file pid.hpp.

target

double light::PID::target = 0.0

Current target.

Definition at line 292 of file pid.hpp.

time

long light::PID::time = 0

Timestamp of last compute (ms).

Definition at line 297 of file pid.hpp.

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

• include/LightLib/control/pid.hpp