frc::BangBangController Class Reference

Implements a bang-bang controller, which outputs either 0 or 1 depending on whether the measurement is less than the setpoint. More...

#include <frc/controller/BangBangController.h>

Inheritance diagram for frc::BangBangController:

Public Member Functions
	BangBangController (double tolerance=std::numeric_limits< double >::infinity())
	Creates a new bang-bang controller. More...
void	SetSetpoint (double setpoint)
	Sets the setpoint for the bang-bang controller. More...
double	GetSetpoint () const
	Returns the current setpoint of the bang-bang controller. More...
bool	AtSetpoint () const
	Returns true if the error is within the tolerance of the setpoint. More...
void	SetTolerance (double tolerance)
	Sets the error within which AtSetpoint will return true. More...
double	GetTolerance () const
	Returns the current tolerance of the controller. More...
double	GetMeasurement () const
	Returns the current measurement of the process variable. More...
double	GetError () const
	Returns the current error. More...
double	Calculate (double measurement, double setpoint)
	Returns the calculated control output. More...
double	Calculate (double measurement)
	Returns the calculated control output. More...
void	InitSendable (wpi::SendableBuilder &builder) override
	Initializes this Sendable object. More...
Public Member Functions inherited from wpi::Sendable
virtual	~Sendable ()=default
virtual void	InitSendable (SendableBuilder &builder)=0
	Initializes this Sendable object. More...
Public Member Functions inherited from wpi::SendableHelper< BangBangController >
	SendableHelper (const SendableHelper &rhs)=default
	SendableHelper (SendableHelper &&rhs)
SendableHelper &	operator= (const SendableHelper &rhs)=default
SendableHelper &	operator= (SendableHelper &&rhs)

Additional Inherited Members
Protected Member Functions inherited from wpi::SendableHelper< BangBangController >
	SendableHelper ()=default
	~SendableHelper ()

Detailed Description

Implements a bang-bang controller, which outputs either 0 or 1 depending on whether the measurement is less than the setpoint.

This maximally-aggressive control approach works very well for velocity control of high-inertia mechanisms, and poorly on most other things.

Note that this is an asymmetric bang-bang controller - it will not exert any control effort in the reverse direction (e.g. it won't try to slow down an over-speeding shooter wheel). This asymmetry is extremely important. Bang-bang control is extremely simple, but also potentially hazardous. Always ensure that your motor controllers are set to "coast" before attempting to control them with a bang-bang controller.

Constructor & Destructor Documentation

BangBangController()

frc::BangBangController::BangBangController ( double  tolerance = std::numeric_limits< double >::infinity() )

explicit

Creates a new bang-bang controller.

Always ensure that your motor controllers are set to "coast" before attempting to control them with a bang-bang controller.

Parameters

tolerance

Tolerance for atSetpoint.

Member Function Documentation

AtSetpoint()

bool frc::BangBangController::AtSetpoint

(

)

const

Returns true if the error is within the tolerance of the setpoint.

Returns

Whether the error is within the acceptable bounds.

Calculate() [1/2]

double frc::BangBangController::Calculate

(

double

measurement

)

Returns the calculated control output.

Parameters

measurement

The most recent measurement of the process variable.

Returns

The calculated motor output (0 or 1).

Calculate() [2/2]

double frc::BangBangController::Calculate	(	double	measurement,
		double	setpoint
	)

Returns the calculated control output.

Always ensure that your motor controllers are set to "coast" before attempting to control them with a bang-bang controller.

Parameters

measurement	The most recent measurement of the process variable.
setpoint	The setpoint for the process variable.

Returns

The calculated motor output (0 or 1).

GetError()

double frc::BangBangController::GetError

(

)

const

Returns the current error.

Returns

The current error.

GetMeasurement()

double frc::BangBangController::GetMeasurement

(

)

const

Returns the current measurement of the process variable.

Returns

The current measurement of the process variable.

GetSetpoint()

double frc::BangBangController::GetSetpoint

(

)

const

Returns the current setpoint of the bang-bang controller.

Returns

The current setpoint.

GetTolerance()

double frc::BangBangController::GetTolerance

(

)

const

Returns the current tolerance of the controller.

Returns

The current tolerance.

InitSendable()

void frc::BangBangController::InitSendable ( wpi::SendableBuilder &  builder )

overridevirtual

Initializes this Sendable object.

Parameters

builder

sendable builder

Implements wpi::Sendable.

SetSetpoint()

void frc::BangBangController::SetSetpoint

(

double

setpoint

)

Sets the setpoint for the bang-bang controller.

Parameters

setpoint

The desired setpoint.

SetTolerance()

void frc::BangBangController::SetTolerance

(

double

tolerance

)

Sets the error within which AtSetpoint will return true.

Parameters

tolerance

Position error which is tolerable.

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

• frc/controller/BangBangController.h