Package com.stuypulse.stuylib.control.feedback

Class PIDController

java.lang.Object

com.stuypulse.stuylib.control.Controller

com.stuypulse.stuylib.control.feedback.PIDController

public class PIDController
extends Controller

The PID algorithm is a feedback control algorithm meant for calculating an output based on an error between a measurement and a setpoint.

PID takes into account the error itself, the rate of change of error, and built-up error over time to create a stable controller.

Because it's a feedback algorithm, it will only react when the system is already behind (there must be error for there to be any output). *However, a feedback contrller can be easily combined with a feedforward model to reduce the delay.*

This PID controller is built by extending the Controller class. It has a dynamic rate, so it can detect how much time has passed between each update. It is made to be easy to use and simple to understand while still being accurate.

Constructor Summary

Constructors

Constructor	Description
PIDController()	Creates a blank PIDController that doesn't move
PIDController(Number p, Number i, Number d)

Method Summary

Modifier and Type	Method	Description
protected double	calculate(double setpoint, double measurement)	Calculates the output of the controller given a setpoint and measurement.
double	getD()
double	getI()
double	getP()
void	reset()	Resets the integrator in the PIDController.
PIDController	setD(Number d)
PIDController	setDerivativeFilter(IFilter... derivativeFilter)	Add a filter to the error velocity / derivative of the PID controller.
PIDController	setI(Number i)
PIDController	setIntegratorFilter(Number range, Number limit)	Add constraints to the integral of the PID Controller
PIDController	setP(Number p)
PIDController	setPID(PIDController pidValues)
PIDController	setPID(Number p, Number i, Number d)

Methods inherited from class com.stuypulse.stuylib.control.Controller

add, getError, getMeasurement, getOutput, getSetpoint, isDone, setMeasurementFilter, setOutputFilter, setSetpointFilter, update

Methods inherited from class java.lang.Object

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

Constructor Details

PIDController

public PIDController(Number p,
 Number i,
 Number d)

Parameters:

p - The Proportional Multiplier

i - The Integral Multiplier

d - The Derivative Multiplier

PIDController

public PIDController()

Creates a blank PIDController that doesn't move

Method Details

reset

public void reset()

Resets the integrator in the PIDController. This automatically gets called if the gap between update() commands is too large

calculate

protected double calculate(double setpoint,
 double measurement)

Description copied from class: Controller

Calculates the output of the controller given a setpoint and measurement.

Specified by:

calculate in class Controller

Parameters:

setpoint - setpoint

measurement - measurement

Returns:

calculated output

getP

public double getP()

Returns:

the P value being used by the PID controller.

getI

public double getI()

Returns:

the P value being used by the PID controller.

getD

public double getD()

Returns:

the P value being used by the PID controller.

setP

public PIDController setP(Number p)

Parameters:

p - new p value used by the PID controller.

Returns:

reference to PIDController (so you can chain the commands together)

setI

public PIDController setI(Number i)

Parameters:

i - new i value used by the PID controller.

Returns:

reference to PIDController (so you can chain the commands together)

setD

public PIDController setD(Number d)

Parameters:

d - new d value used by the PID controller.

Returns:

reference to PIDController (so you can chain the commands together)

setPID

public PIDController setPID(Number p,
 Number i,
 Number d)

Parameters:

p - new p value used by the PID controller.

i - new i value used by the PID controller.

d - new d value used by the PID controller.

Returns:

reference to PIDController (so you can chain the commands together)

setPID

public PIDController setPID(PIDController pidValues)

Parameters:

pidValues - PIDController that stores the PID values

Returns:

reference to PIDController (so you can chain the commands together)

setIntegratorFilter

public PIDController setIntegratorFilter(Number range,
 Number limit)

Add constraints to the integral of the PID Controller

Parameters:

range - the range of error in which the integral is allowed to accumulate (0 will disable)

limit - the max / min the integral is allowed to accumulate to (0 will disables)

Returns:

reference to PIDController (so you can chain the commands together)

setDerivativeFilter

public PIDController setDerivativeFilter(IFilter... derivativeFilter)

Add a filter to the error velocity / derivative of the PID controller.

Parameters:

derivativeFilter - the filter to apply to derivative

Returns:

reference to PIDController (so you can chain the commands together)