Package trclib.archive

Class TrcCascadePidController

java.lang.Object

trclib.robotcore.TrcPidController

trclib.archive.TrcCascadePidController

public class TrcCascadePidController
extends TrcPidController

This class implements a Cascade PID Controller. A Cascade PID controller consists of two PID controllers in cascade. The output of the primary PID controller feeds into the input of the secondary PID controller. If the motor is not linear, it may be very difficult to get good performance out of a single PID controller. In Cascade PID control, the distance set-point, for example, will produce a speed control as the primary output and feeds into the secondary PID controller as input that will try to compensate for the non-linearity of the motor or even battery level changes. The TrcCascadePidController class extends a regular PID control as its primary PID controller and creates a second PID controller as its secondary controller.

Nested Class Summary

Nested classes/interfaces inherited from class trclib.robotcore.TrcPidController

TrcPidController.PidCoefficients, TrcPidController.PidInput

Field Summary

Fields

Modifier and Type	Field	Description
TrcPidController	secondaryCtrl

Fields inherited from class trclib.robotcore.TrcPidController

DEF_SETTLING_TIME, tracer

Constructor Summary

Constructors

Constructor	Description
TrcCascadePidController(String instanceName, TrcPidController.PidCoefficients primaryPidCoefficients, TrcPidController.PidCoefficients secondaryPidCoefficients, TrcPidController.PidInput primaryInput, TrcPidController.PidInput secondaryInput)	Constructor: Create an instance of the object.

Method Summary

Modifier and Type	Method	Description
double	getOutput()	This method calculates the Cascade PID control output by calling the primary PID controller, feeding its output to the secondary PID controller and finally returning the output of the secondary PID controller.
void	reset()	This method is called to reset the Cascade PID controller.

Methods inherited from class trclib.robotcore.TrcPidController

displayPidInfo, endStallDetection, getCurrentInput, getError, getOutput, getOutputLimit, getPidCoefficients, getPidInput, getTarget, hasAbsoluteSetPoint, isOnTarget, isOnTarget, isStalled, printPidInfo, printPidInfo, printPidInfo, printPidInfo, restoreOutputLimit, saveAndSetOutputLimit, setAbsoluteSetPoint, setInverted, setNoOscillation, setOutputLimit, setOutputRange, setPidCoefficients, setRampRate, setStallDetectionEnabled, setStallDetectionEnabled, setTarget, setTarget, setTarget, setTarget, setTraceLevel, setTraceLevel, setTraceLevel, startStallDetection, toString

Methods inherited from class java.lang.Object

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

Field Details

secondaryCtrl

public TrcPidController secondaryCtrl

Constructor Details

TrcCascadePidController

public TrcCascadePidController(String instanceName,
 TrcPidController.PidCoefficients primaryPidCoefficients,
 TrcPidController.PidCoefficients secondaryPidCoefficients,
 TrcPidController.PidInput primaryInput,
 TrcPidController.PidInput secondaryInput)

Constructor: Create an instance of the object.

Parameters:

instanceName - specifies the instance name.

primaryPidCoefficients - specifies the PID coefficients of the primary PID controller.

secondaryPidCoefficients - specifies the PID coefficients of the secondary PID controller.

primaryInput - specifies the supplier of the primary PID input.

secondaryInput - specifies the supplier of the secondary PID input.

Method Details

reset

public void reset()

This method is called to reset the Cascade PID controller. It resets both the primary and secondary PID controller.

Overrides:

reset in class TrcPidController

getOutput

public double getOutput()

This method calculates the Cascade PID control output by calling the primary PID controller, feeding its output to the secondary PID controller and finally returning the output of the secondary PID controller.

Overrides:

getOutput in class TrcPidController

Returns:

output of the Cascade PID controller.