ADBLib::SimplePID Class Reference

#include <SimplePID.h>

Public Member Functions
	SimplePID (double p, double i, double d, bool continuous, double period=0.05)
	~SimplePID ()
double	getOutput ()
void	setInputRange (double minimumInput, double maximumInput)
void	setOutputRange (double mimimumOutput, double maximumOutput)
void	setPID (double p, double i, double d)
void	setMV (double mv)
void	setSetpoint (double setpoint)
double	setSetpoint ()
double	setError ()
void	setTolerance (double percent)
bool	onTarget ()
void	enable ()
void	disable ()
void	reset ()

Protected Member Functions
void	calculate ()

Static Protected Member Functions
static void	callCalculate (void *controller)

Protected Attributes
double	m_P
double	m_I
double	m_D
double	m_maximumOutput
double	m_minimumOutput
double	m_maximumInput
double	m_minimumInput
bool	m_continuous
bool	m_enabled
double	m_prevError
double	m_totalError
double	m_tolerance
double	m_setpoint
double	m_error
double	m_result
double	m_period
double	m_measuredValue
Notifier *	m_controlLoop

Detailed Description

Class for doing PID calculations without slaving an output into a PIDController object. Class originally by Parker Stebbins, adapted for use in ADBLib in 2016.

To use this class, first give it your PID values, select whether input is continuous, and select a control period (default is 50 ms). To provide sensor input, call setMV() and provide your sensor input. To set a setpoint, use setSetpoint(). To get the calculated value that your output should be set to, call getOutput().

Note

You MUST call enable(), all SimplePID objects start as DISABLED!

Constructor & Destructor Documentation

ADBLib::SimplePID::SimplePID	(	double	Kp,
		double	Ki,
		double	Kd,
		bool	continuous,
		double	period = 0.05
	)

Create a PID object with the given constants for P, I, D. Default values for min/max IO are -1 and 1 respectively, continuous input is disabled, tolerance is set to 5%, and the SimplePID starts as disabled (zero output).

Parameters

Kp	The proportional coefficient
Ki	The integral coefficient
Kd	The derivative coefficient
period	The loop time for doing calculations in seconds. This particularly affects calculations of the integral and differential terms. The default is 50 ms.

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ADBLib::SimplePID::~SimplePID

(

)

Destroys this object.

Member Function Documentation

void ADBLib::SimplePID::calculate ( )

protected

Internal function. Performs necessary PID calculations.

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void ADBLib::SimplePID::callCalculate ( void *  controller )

staticprotected

Internal function. Calls the calculate function... for some reason.

Parameters

controller

A pointer to a SimplePID object.

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void ADBLib::SimplePID::disable

(

)

Disables the SimplePID, zeroing output from getOutput().

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void ADBLib::SimplePID::enable

(

)

Enables the SimplePID, starting output from getOutput().

double ADBLib::SimplePID::getOutput

(

)

Gets the output as calculated using input and setpoint.

Returns

The output from the PID calculation. Give this to the object you want work with (eg. a motor).

bool ADBLib::SimplePID::onTarget

(

)

Returns the status of whether this PID controller is on target or not to within tolerance set by the SetTolerance function. Tolerance is set at 5% by default. Calculation is done by getting the absolute value of error and checking whether it's less than the tolerance times the input range.

Returns

True for on-target, false otherwise.

void ADBLib::SimplePID::reset

(

)

Resets the SimplePID, disabling it and resetting all error and calculated output.

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double ADBLib::SimplePID::setError

(

)

void ADBLib::SimplePID::setInputRange	(	double	minimumInput,
		double	maximumInput
	)

Sets the input range this object expects. For example. a gyro could output from -180 to 180, so you would call this function with Set

Parameters

minimumInput	The minimum input expected. Can be negative.
maximumInput	The maximum input expected.

Todo:

Investigate "SetSetpoint(m_setpoint)"

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void ADBLib::SimplePID::setMV

(

double

mv

)

Sets the measured value, presumably from sensors.

Parameters

mv	The measured value as a double.

void ADBLib::SimplePID::setOutputRange	(	double	minimumOutput,
		double	maximumOutput
	)

Sets the output range delivered. For example, if you have a drivebase expecting values between -512 and 512, call this function with -512 and 512, respectively.

Parameters

minimumOutput	The minimum output delivered. Can be negative.
maximumOutput	The maximum output delivered.

void ADBLib::SimplePID::setPID	(	double	p,
		double	i,
		double	d
	)

Sets PID constants.

Parameters

p	The proportional constant. Multiplied by the error.
i	The integral constant. Multiplied by the sum of error.
d	The derivative constant. Multiplied by the rate at which error is changing.

void ADBLib::SimplePID::setSetpoint

(

double

setpoint

)

Sets the point that PID calculations will try to work towards. This value should be somewhere within the output range, which by default is from -1 to 1. This function can and should be used similarly to motor set functions.

Parameters

setpoint

The desired setpoint.

double ADBLib::SimplePID::setSetpoint

(

)

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void ADBLib::SimplePID::setTolerance

(

double

tolerance

)

Sets the tolerance to error.

Parameters

tolerance

Tolerance as a percent (eg. 0.02)

Member Data Documentation

bool ADBLib::SimplePID::m_continuous

protected

Notifier* ADBLib::SimplePID::m_controlLoop

protected

double ADBLib::SimplePID::m_D

protected

bool ADBLib::SimplePID::m_enabled

protected

double ADBLib::SimplePID::m_error

protected

double ADBLib::SimplePID::m_I

protected

double ADBLib::SimplePID::m_maximumInput

protected

double ADBLib::SimplePID::m_maximumOutput

protected

double ADBLib::SimplePID::m_measuredValue

protected

double ADBLib::SimplePID::m_minimumInput

protected

double ADBLib::SimplePID::m_minimumOutput

protected

double ADBLib::SimplePID::m_P

protected

double ADBLib::SimplePID::m_period

protected

double ADBLib::SimplePID::m_prevError

protected

double ADBLib::SimplePID::m_result

protected

double ADBLib::SimplePID::m_setpoint

protected

double ADBLib::SimplePID::m_tolerance

protected

double ADBLib::SimplePID::m_totalError

protected

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

• src/control/SimplePID.h
• src/control/SimplePID.cpp