PID Class Reference

Implements a proportional-integral-derivative (PID) controller. More...

#include <PID.h>

Public Member Functions
	PID ()
	Default constructor for PID, initializes gains to zero.
	PID (float kp, float ki, float kd)
	Constructs a PID controller with specified gains.
	~PID ()
	Destructor for PID.
float	Calculate (float setpoint, float processVariable, unsigned long currentMillis)
	Calculates the control output based on the setpoint and process variable.
float	Calculate (float setpoint, float processVariable, float dT)
	Calculates the control output based on the setpoint and process variable.

Private Attributes
float	integral
	Integral term accumulator.
float	error
	Current error value.
float	previousError
	Previous error value for derivative calculation.
float	output
	Calculated output value.
float	kp
	Proportional gain.
float	ki
	Integral gain.
float	kd
	Derivative gain.
float	previousSeconds
	Time of the previous calculation in seconds.

Detailed Description

Implements a proportional-integral-derivative (PID) controller.

This class calculates control outputs based on the error between a setpoint and a process variable, using configurable proportional, integral, and derivative gains.

Definition at line 22 of file PID.h.

Constructor & Destructor Documentation

PID() [1/2]

PID

(

)

Default constructor for PID, initializes gains to zero.

Definition at line 3 of file PID.cpp.

PID() [2/2]

PID	(	float	kp,
		float	ki,
		float	kd
	)

Constructs a PID controller with specified gains.

Parameters

kp	Proportional gain.
ki	Integral gain.
kd	Derivative gain.

Definition at line 13 of file PID.cpp.

~PID()

~PID

(

)

Destructor for PID.

Definition at line 23 of file PID.cpp.

Member Function Documentation

Calculate() [1/2]

float Calculate	(	float	setpoint,
		float	processVariable,
		float	dT
	)

Calculates the control output based on the setpoint and process variable.

This method requires the caller to provide the time delta in seconds since the last calculation.

Parameters

setpoint	Desired target value.
processVariable	Current value of the process variable.
dT	Time delta in seconds since the last calculation.

Returns

Calculated control output.

Definition at line 46 of file PID.cpp.

References error, integral, kd, ki, kp, output, and previousError.

Calculate() [2/2]

float Calculate	(	float	setpoint,
		float	processVariable,
		unsigned long	currentMillis
	)

Calculates the control output based on the setpoint and process variable.

This method uses the elapsed time in milliseconds since the last call to calculate the derivative term.

Parameters

setpoint	Desired target value.
processVariable	Current value of the process variable.
currentMillis	Current time in milliseconds.

Returns

Calculated control output.

Definition at line 25 of file PID.cpp.

References error, integral, kd, ki, kp, output, previousError, and previousSeconds.

Member Data Documentation

error

float error

private

Current error value.

Definition at line 25 of file PID.h.

Referenced by Calculate(), and Calculate().

integral

float integral

private

Integral term accumulator.

Definition at line 24 of file PID.h.

Referenced by Calculate(), and Calculate().

kd

float kd

private

Derivative gain.

Definition at line 30 of file PID.h.

Referenced by Calculate(), and Calculate().

ki

float ki

private

Integral gain.

Definition at line 29 of file PID.h.

Referenced by Calculate(), and Calculate().

kp

float kp

private

Proportional gain.

Definition at line 28 of file PID.h.

Referenced by Calculate(), and Calculate().

output

float output

private

Calculated output value.

Definition at line 27 of file PID.h.

Referenced by Calculate(), and Calculate().

previousError

float previousError

private

Previous error value for derivative calculation.

Definition at line 26 of file PID.h.

Referenced by Calculate(), and Calculate().

previousSeconds

float previousSeconds

private

Time of the previous calculation in seconds.

Definition at line 31 of file PID.h.

Referenced by Calculate().

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

• PID.h
• PID.cpp