io.github.robolib.module.controller

Class PIDController

java.lang.Object

io.github.robolib.module.controller.PIDController

All Implemented Interfaces:

LiveWindowSendable, Sendable, UpdatingSendable

public class PIDController
extends java.lang.Object
implements LiveWindowSendable

Author:

noriah

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private class	PIDController.PIDTask The task each PIDController runs
static interface	PIDController.Tolerance Interface for representing the error and tolerance of the PID

Field Summary

Fields

Modifier and Type	Field and Description
static double	DEFAULT_PERIOD
private boolean	m_continuous
(package private) java.util.Timer	m_controlLoop
private double	m_D
private boolean	m_enabled
private double	m_error
private double	m_F
private double	m_I
private static int	m_instances
private ITableListener	m_listener
private double	m_maxInput
private double	m_maxOutput
private double	m_minInput
private double	m_minOutput
private double	m_P
private double	m_prevError
private double	m_result
private double	m_setpoint
(package private) PIDSink	m_sink
(package private) PIDSource	m_source
private ITable	m_table
private PIDController.Tolerance	m_tolerance
private double	m_totalError

Constructor Summary

Constructors

Constructor and Description
PIDController(double p, double i, double d, double f, PIDSource source, PIDSink sink) Allocate a PID object with the given constants for P, I, D, using a 50ms period.
PIDController(double p, double i, double d, double f, PIDSource source, PIDSink sink, double period) Allocate a PID object with the given constants for P, I, D, and F
PIDController(double p, double i, double d, PIDSource source, PIDSink sink) Allocate a PID object with the given constants for P, I, D, using a 50ms period.
PIDController(double p, double i, double d, PIDSource source, PIDSink sink, double period) Allocate a PID object with the given constants for P, I, D and period

Method Summary

Modifier and Type	Method and Description
private void	calculate() Read the input, calculate the output accordingly, and write to the output.
void	disable() Stop running the PIDController, this sets the output to zero before stopping.
void	enable() Begin running the PIDController
void	free()
double	get() Return the current PID result This is always centered on zero and constrained the the max and min outs
double	getD() Get the Differential coefficient
double	getError() Returns the current difference of the input from the setpoint
double	getF() Get the Feed forward coefficient
double	getI() Get the Integral coefficient
double	getP() Get the Proportional coefficient
double	getSetpoint() Returns the current setpoint of the PIDController
java.lang.String	getSmartDashboardType()
ITable	getTable()
void	initTable(ITable table)
boolean	isEnabled() Return true if PIDController is enabled.
boolean	onTarget() Return true if the error is within the percentage of the total input range, determined by setTolerance.
void	reset() Reset the previous error,, the integral term, and disable the controller.
void	setAbsoluteTolerance(double absValue) Set the absolute error which is considered tolerable for use with OnTarget.
void	setContinuous() Set the PID controller to consider the input to be continuous, Rather then using the max and min in as constraints, it considers them to be the same point and automatically calculates the shortest route to the setpoint.
void	setContinuous(boolean continuous) Set the PID controller to consider the input to be continuous, Rather then using the max and min in as constraints, it considers them to be the same point and automatically calculates the shortest route to the setpoint.
void	setInputRange(double min, double max) Sets the maximum and minimum values expected from the input and setpoint.
void	setOutputRange(double min, double max) Sets the minimum and maximum values to write.
void	setPercentTolerance(double percentage) Set the percentage error which is considered tolerable for use with OnTarget.
void	setPID(double p, double i, double d) Set the PID Controller gain parameters.
void	setPID(double p, double i, double d, double f) Set the PID Controller gain parameters.
void	setSetpoint(double point) Set the setpoint for the PIDController
void	setTolerance(PIDController.Tolerance tolerance) Set the PID tolerance using a Tolerance object.
void	startLiveWindowMode()
void	stopLiveWindowMode()
void	updateTable()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_PERIOD

public static final double DEFAULT_PERIOD

See Also:

Constant Field Values

m_instances

private static int m_instances

m_P

private double m_P

m_I

private double m_I

m_D

private double m_D

m_F

private double m_F

m_maxOutput

private double m_maxOutput

m_minOutput

private double m_minOutput

m_maxInput

private double m_maxInput

m_minInput

private double m_minInput

m_continuous

private boolean m_continuous

m_enabled

private boolean m_enabled

m_prevError

private double m_prevError

m_totalError

private double m_totalError

m_tolerance

private PIDController.Tolerance m_tolerance

m_setpoint

private double m_setpoint

m_error

private double m_error

m_result

private double m_result

m_source

PIDSource m_source

m_sink

PIDSink m_sink

m_controlLoop

java.util.Timer m_controlLoop

m_table

private ITable m_table

m_listener

private final ITableListener m_listener

Constructor Detail

PIDController

public PIDController(double p,
                     double i,
                     double d,
                     double f,
                     PIDSource source,
                     PIDSink sink,
                     double period)

Allocate a PID object with the given constants for P, I, D, and F

Parameters:

p - the proportional coefficient

i - the integral coefficient

d - the derivative coefficient

f - the feed forward term

source - The PIDSource object that is used to get values

sink - The PIDOutput object that is set to the output percentage

period - the loop time for doing calculations. This particularly effects calculations of the integral and differential terms. The default is 50ms.

PIDController

public PIDController(double p,
                     double i,
                     double d,
                     PIDSource source,
                     PIDSink sink,
                     double period)

Allocate a PID object with the given constants for P, I, D and period

Parameters:

p - the proportional coefficient

i - the integral coefficient

d - the derivative coefficient

source - the PIDSource object that is used to get values

sink - the PIDOutput object that is set to the output percentage

period - the loop time for doing calculations. This particularly effects calculations of the integral and differential terms. The default is 50ms.

PIDController

public PIDController(double p,
                     double i,
                     double d,
                     PIDSource source,
                     PIDSink sink)

Allocate a PID object with the given constants for P, I, D, using a 50ms period.

Parameters:

p - the proportional coefficient

i - the integral coefficient

d - the derivative coefficient

source - The PIDSource object that is used to get values

sink - The PIDOutput object that is set to the output percentage

PIDController

public PIDController(double p,
                     double i,
                     double d,
                     double f,
                     PIDSource source,
                     PIDSink sink)

Allocate a PID object with the given constants for P, I, D, using a 50ms period.

Parameters:

p - the proportional coefficient

i - the integral coefficient

d - the derivative coefficient

f - the feed forward term

source - The PIDSource object that is used to get values

sink - The PIDOutput object that is set to the output percentage

Method Detail

free

public void free()

calculate

private void calculate()

Read the input, calculate the output accordingly, and write to the output. This should only be called by the PIDTask and is created during initialization.

setPID

public void setPID(double p,
                   double i,
                   double d)

Set the PID Controller gain parameters. Set the proportional, integral, and differential coefficients.

Parameters:

p - Proportional coefficient

i - Integral coefficient

d - Differential coefficient

setPID

public void setPID(double p,
                   double i,
                   double d,
                   double f)

Set the PID Controller gain parameters. Set the proportional, integral, and differential coefficients.

Parameters:

p - Proportional coefficient

i - Integral coefficient

d - Differential coefficient

f - Feed forward coefficient

getP

public double getP()

Get the Proportional coefficient

Returns:

proportional coefficient

getI

public double getI()

Get the Integral coefficient

Returns:

integral coefficient

getD

public double getD()

Get the Differential coefficient

Returns:

differential coefficient

getF

public double getF()

Get the Feed forward coefficient

Returns:

feed forward coefficient

get

public double get()

Return the current PID result This is always centered on zero and constrained the the max and min outs

Returns:

the latest calculated output

setContinuous

public void setContinuous(boolean continuous)

Set the PID controller to consider the input to be continuous, Rather then using the max and min in as constraints, it considers them to be the same point and automatically calculates the shortest route to the setpoint.

Parameters:

continuous - Set to true turns on continuous, false turns off continuous

setContinuous

public void setContinuous()

Set the PID controller to consider the input to be continuous, Rather then using the max and min in as constraints, it considers them to be the same point and automatically calculates the shortest route to the setpoint.

setInputRange

public void setInputRange(double min,
                          double max)

Sets the maximum and minimum values expected from the input and setpoint.

Parameters:

min - the minimum value expected from the input

max - the maximum value expected from the input

setOutputRange

public void setOutputRange(double min,
                           double max)

Sets the minimum and maximum values to write.

Parameters:

min - the minimum percentage to write to the output

max - the maximum percentage to write to the output

setSetpoint

public void setSetpoint(double point)

Set the setpoint for the PIDController

Parameters:

point - the desired setpoint

getSetpoint

public double getSetpoint()

Returns the current setpoint of the PIDController

Returns:

the current setpoint

getError

public double getError()

Returns the current difference of the input from the setpoint

Returns:

the current error

setTolerance

public void setTolerance(PIDController.Tolerance tolerance)

Set the PID tolerance using a Tolerance object. Tolerance can be specified as a percentage of the range or as an absolute value. The Tolerance object encapsulates those options in an object. Use it by creating the type of tolerance that you want to use: setTolerance(new PIDController.AbsoluteTolerance(0.1))

Parameters:

tolerance - a tolerance object of the right type, e.g. PercentTolerance or AbsoluteTolerance

setPercentTolerance

public void setPercentTolerance(double percentage)

Set the percentage error which is considered tolerable for use with OnTarget. (Input of 15.0 = 15 percent)

Parameters:

percentage - percent error which is tolerable

setAbsoluteTolerance

public void setAbsoluteTolerance(double absValue)

Set the absolute error which is considered tolerable for use with OnTarget.

Parameters:

absValue - absolute error which is tolerable in the units of the input object

onTarget

public boolean onTarget()

Return true if the error is within the percentage of the total input range, determined by setTolerance. This assumes that the maximum and minimum input were set using setInput.

Returns:

true if the error is less than the tolerance

enable

public void enable()

Begin running the PIDController

disable

public void disable()

Stop running the PIDController, this sets the output to zero before stopping.

isEnabled

public boolean isEnabled()

Return true if PIDController is enabled.

reset

public void reset()

Reset the previous error,, the integral term, and disable the controller.

getSmartDashboardType

public java.lang.String getSmartDashboardType()

Specified by:

getSmartDashboardType in interface Sendable

initTable

public void initTable(ITable table)

Specified by:

initTable in interface Sendable

getTable

public ITable getTable()

Specified by:

getTable in interface Sendable

updateTable

public void updateTable()

Specified by:

updateTable in interface UpdatingSendable

startLiveWindowMode

public void startLiveWindowMode()

Specified by:

startLiveWindowMode in interface LiveWindowSendable

stopLiveWindowMode

public void stopLiveWindowMode()

Specified by:

stopLiveWindowMode in interface LiveWindowSendable