ptolemy.domains.ct.lib
Class CTRateLimiter

java.lang.Object
  ptolemy.kernel.util.NamedObj
      ptolemy.kernel.InstantiableNamedObj
          ptolemy.kernel.Entity
              ptolemy.kernel.ComponentEntity
                  ptolemy.actor.AtomicActor
                      ptolemy.actor.TypedAtomicActor
                          ptolemy.actor.lib.Transformer
                              ptolemy.domains.ct.lib.CTRateLimiter

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, Actor, Executable, FiringsRecordable, Initializable, TypedActor, Changeable, Debuggable, DebugListener, Derivable, Instantiable, ModelErrorHandler, MoMLExportable, Moveable, Nameable

public class CTRateLimiter
extends Transformer

This actor limits the first derivative of the input signal (u). The output (y) changes no faster than the specified limit. The derivative is calculated using this equation:

         u(k) - y(k-1)
 rate = --------------
         t(k) - t(k-1)
 

where u(k) and t(k) are the current input and time, and y(k-1) and t(k-1) are the output and time at the previous step. The output is determined by comparing rate to the risingSlewRate and fallingSlewRate parameters.

• If rate is greater than risingSlewRate, the output is

   y(k) = (t(k)-t(k-1))*risingSlewRate + y(k-1)
   

• If rate is less than fallingSlewRate, the output is

   y(k) = (t(k)-t(k-1))*fallingSlewRate + y(k-1)
   

• Otherwise, just output the input.

This actor works as a (continuous) nonlinear function. It does not control integration step sizes. Notice that this actor does not try to find the time instant that the input rate reaches the rising slew rate or falling slew rate. As a consequence, this may cause some ODE solvers not converging under some circumstances.

FIXME: This actor should implement the CTStateful interface to support rollback.

Since:

Ptolemy II 1.0

Version:

$Id: CTRateLimiter.java 57040 2010-01-27 20:52:32Z cxh $

Author:

Jie Liu

See Also:

Serialized Form

Accepted Rating:

Red (cxh)

Proposed Rating:

Red (liuj)

Nested Class Summary

Nested classes/interfaces inherited from class ptolemy.kernel.Entity

Entity.ContainedObjectsIterator

Field Summary

private Time	_lastTime
private Token	_lastToken
private Token	_newToken
Parameter	fallingSlewRate The rising slew rate.
Parameter	risingSlewRate The rising slew rate.

Fields inherited from class ptolemy.actor.lib.Transformer

input, output

Fields inherited from class ptolemy.actor.AtomicActor

_actorFiringListeners, _initializables, _notifyingActorFiring, _stopRequested

Fields inherited from class ptolemy.kernel.util.NamedObj

_changeListeners, _changeLock, _changeRequests, _debugging, _debugListeners, _elementName, _isPersistent, _verbose, _workspace, ATTRIBUTES, CLASSNAME, COMPLETE, CONTENTS, DEEP, FULLNAME, LINKS

Fields inherited from interface ptolemy.actor.Executable

COMPLETED, NOT_READY, STOP_ITERATING

Constructor Summary

CTRateLimiter(CompositeEntity container, java.lang.String name)
Construct an actor with the given container and name.

Method Summary

void	fire() Compute the change rate of the input and compare it to the risingSlewRate and the fallingSlewRate.
void	initialize() Initialize the local time variables and the cache of last token.
boolean	postfire() Update the time and value for this iteration.

Methods inherited from class ptolemy.actor.TypedAtomicActor

_addPort, _fireAt, _fireAt, attributeTypeChanged, clone, newPort, typeConstraintList, typeConstraints

Methods inherited from class ptolemy.actor.AtomicActor

_actorFiring, _actorFiring, addActorFiringListener, addInitializable, clone, connectionsChanged, createReceivers, declareDelayDependency, getCausalityInterface, getDirector, getExecutiveDirector, getManager, inputPortList, isFireFunctional, isStrict, iterate, newReceiver, outputPortList, prefire, preinitialize, pruneDependencies, recordFiring, removeActorFiringListener, removeDependency, removeInitializable, setContainer, stop, stopFire, terminate, wrapup

Methods inherited from class ptolemy.kernel.ComponentEntity

_adjustDeferrals, _checkContainer, _getContainedObject, _propagateExistence, getContainer, instantiate, isAtomic, isOpaque, moveDown, moveToFirst, moveToIndex, moveToLast, moveUp, propagateExistence, setName

Methods inherited from class ptolemy.kernel.Entity

_description, _exportMoMLContents, _removePort, _validateSettables, connectedPortList, connectedPorts, containedObjectsIterator, getAttribute, getPort, getPorts, linkedRelationList, linkedRelations, portList, removeAllPorts, setClassDefinition, uniqueName

Methods inherited from class ptolemy.kernel.InstantiableNamedObj

_setParent, exportMoML, getChildren, getElementName, getParent, getPrototypeList, isClassDefinition, isWithinClassDefinition

Methods inherited from class ptolemy.kernel.util.NamedObj

_addAttribute, _adjustOverride, _attachText, _cloneFixAttributeFields, _debug, _debug, _debug, _debug, _debug, _getIndentPrefix, _isMoMLSuppressed, _markContentsDerived, _propagateValue, _recordDecoratedAttributes, _removeAttribute, _splitName, _stripNumericSuffix, addChangeListener, addDebugListener, attributeChanged, attributeList, attributeList, deepContains, depthInHierarchy, description, description, event, executeChangeRequests, exportMoML, exportMoML, exportMoML, exportMoML, exportMoMLPlain, getAttribute, getAttributes, getChangeListeners, getClassName, getDecoratorAttribute, getDecoratorAttributes, getDerivedLevel, getDerivedList, getDisplayName, getFullName, getModelErrorHandler, getName, getName, getSource, handleModelError, isDeferringChangeRequests, isOverridden, isPersistent, lazyContainedObjectsIterator, message, propagateValue, propagateValues, removeChangeListener, removeDebugListener, requestChange, setClassName, setDeferringChangeRequests, setDerivedLevel, setDisplayName, setModelErrorHandler, setPersistent, setSource, sortContainedObjects, toplevel, toString, validateSettables, workspace

Methods inherited from class java.lang.Object

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

Methods inherited from interface ptolemy.actor.Actor

createReceivers, getCausalityInterface, getDirector, getExecutiveDirector, getManager, inputPortList, newReceiver, outputPortList

Methods inherited from interface ptolemy.actor.Executable

isFireFunctional, isStrict, iterate, prefire, stop, stopFire, terminate

Methods inherited from interface ptolemy.actor.Initializable

addInitializable, preinitialize, removeInitializable, wrapup

Methods inherited from interface ptolemy.kernel.util.Nameable

description, getContainer, getDisplayName, getFullName, getName, getName, setName

Methods inherited from interface ptolemy.kernel.util.Derivable

getDerivedLevel, getDerivedList, propagateValue

Field Detail

risingSlewRate

public Parameter risingSlewRate

The rising slew rate. The parameter has type double and default value 1.0.

fallingSlewRate

public Parameter fallingSlewRate

The rising slew rate. The parameter has type double and default value -1.0.

_lastTime

private Time _lastTime

_lastToken

private Token _lastToken

_newToken

private Token _newToken

Constructor Detail

CTRateLimiter

public CTRateLimiter(CompositeEntity container,
                     java.lang.String name)
              throws NameDuplicationException,
                     IllegalActionException

Construct an actor with the given container and name.

Parameters:

container - The container.

name - The name of this actor.

Throws:

IllegalActionException - If the actor cannot be contained by the proposed container.

NameDuplicationException - If the container already has an actor with this name.

Method Detail

fire

public void fire()
          throws IllegalActionException

Compute the change rate of the input and compare it to the risingSlewRate and the fallingSlewRate. If the rate is outside the range defined by the parameters, it will output the bounded signal. If there is no input, then produce no output.

Specified by:

fire in interface Executable

Overrides:

fire in class AtomicActor

Throws:

IllegalActionException - If there is no director.

initialize

public void initialize()
                throws IllegalActionException

Initialize the local time variables and the cache of last token.

Specified by:

initialize in interface Initializable

Overrides:

initialize in class AtomicActor

Throws:

IllegalActionException - If the super cclass throws it.

postfire

public boolean postfire()
                 throws IllegalActionException

Update the time and value for this iteration. Return the same value as super.postfire().

Specified by:

postfire in interface Executable

Overrides:

postfire in class AtomicActor

Returns:

True if execution can continue into the next iteration.

Throws:

IllegalActionException - If the director throws it when scheduling the next firing.