artisynth.core.mechmodels

Class JointActuator

java.lang.Object

artisynth.core.modelbase.ModelComponentBase

artisynth.core.mechmodels.JointActuator

All Implemented Interfaces:

ExcitationComponent, ForceComponent, ForceEffector, HasNumericState, ModelComponent, PostScannable, ScalableUnits, java.lang.Cloneable, HasProperties, HierarchyNode, Scannable

public class JointActuator
extends ModelComponentBase
implements ExcitationComponent, ForceComponent, HasNumericState, ScalableUnits

Applies, as an external force, the generalized force associated with a joint coordinate. This is done by setting the actuator's excitation property, which is then scaled by the forceScale property to determine the actual applied force.

Nested Class Summary

Nested classes/interfaces inherited from interface artisynth.core.mechmodels.ExcitationComponent

ExcitationComponent.CombinationRule

Nested classes/interfaces inherited from interface artisynth.core.modelbase.ModelComponent

ModelComponent.FilePathSaveType, ModelComponent.NavpanelVisibility

Field Summary

Fields

Modifier and Type	Field and Description
static boolean	DEFAULT_ENABLED
static double	DEFAULT_EXCITATION
static double	DEFAULT_FORCE_SCALE
static PropertyList	myProps

Fields inherited from class artisynth.core.modelbase.ModelComponentBase

enforceUniqueCompositeNames, enforceUniqueNames, myNumber, NULL_OBJ, useCompactPathNames

Constructor Summary

Constructors

Constructor and Description
JointActuator() No-args constructor needed for write/scan.
JointActuator(JointCoordinateHandle ch, double forceScale) Creates an unnamed JointActuator from a specified coordinate handle.
JointActuator(java.lang.String name, JointBase joint, int idx, double forceScale) Creates a named JointActuator from a specified joint and coordinate index.
JointActuator(java.lang.String name, JointCoordinateHandle ch, double forceScale) Creates a named JointActuator from a specified coordinate handle.

Method Summary

Modifier and Type	Method and Description
void	addExcitationSource(ExcitationComponent ex, double gain) Adds a new excitation source to this Excitable with a specified gain.
void	addPosJacobian(SparseNumberedBlockMatrix M, double s) Scales the components of the position Jacobian associated with this force effector and adds it to the supplied solve matrix M.
void	addSolveBlocks(SparseNumberedBlockMatrix M) Adds any needed blocks to a solve matrix in order to accomodate the Jacobian terms associated with this force effector.
void	addVelJacobian(SparseNumberedBlockMatrix M, double s) Scales the components of the velocity Jacobian associated with this force effector and adds it to the supplied solve matrix M.
void	applyForces(double t) Adds forces to the components affected by this force effector at a particular time.
static java.util.ArrayList<JointActuator>	createActuators(MechModel mech, JointBase joint, double forceScale) Creates a complete set of JointActuators for all coordinates associated with a specific joint.
PropertyList	getAllPropertyInfo() Returns a list giving static information about all properties exported by this object.
ExcitationComponent.CombinationRule	getCombinationRule() Return the combination rule for excitations.
JointCoordinateHandle	getCoordinateHandle() Returns the handle for the coordinate/joint pair used by this JointActuator.
double	getExcitation() Queries the excitation associated with this JointActuator.
double	getExcitationGain(ExcitationComponent ex) Gets the gain for an excitation source in this component.
double	getForceScale() Queries the force scale associated with this JointActuator.
void	getHardReferences(java.util.List<ModelComponent> refs) Appends all hard references for this component to a list.
int	getJacobianType() Returns a code indicating the matrix type that results when the Jacobian terms of this force effector are added to the solve matrix.
double	getNetExcitation() Returns the net excitation for this Excitable.
void	getSoftReferences(java.util.List<ModelComponent> refs) Appends all soft references for this component to a list.
void	getState(DataBuffer data) Saves state information for this component by adding data to the supplied DataBuffer.
boolean	hasState() Queries if this component has state.
boolean	isEnabled() Queries whether this actuator is enabled.
boolean	removeExcitationSource(ExcitationComponent ex) Removes an excitation source from this Excitable.
void	scaleDistance(double s) Scales all distance coordinates.
void	scaleMass(double s) Scales all mass units.
void	setCombinationRule(ExcitationComponent.CombinationRule rule) Sets the rule for combining excitations.
void	setEnabled(boolean enabled) Sets whether or not this actuator is enabled.
void	setExcitation(double e) Sets the excitation associated with this JointActuator.
boolean	setExcitationGain(ExcitationComponent ex, double gain) Sets the gain for an excitation source in this component.
void	setForceScale(double s) Sets the force scale associated with this JointActuator.
void	setState(DataBuffer data) Restores the state for this component by reading from the supplied data buffer, starting at the current buffer offsets.
void	updateReferences(boolean undo, java.util.Deque<java.lang.Object> undoInfo) May be called by the system if any of the soft references for this component are removed from the the component hierarchy.

Methods inherited from class artisynth.core.modelbase.ModelComponentBase

checkFlag, checkName, checkNameUniqueness, clearFlag, clone, connectToHierarchy, copy, createTempFlag, disconnectFromHierarchy, getChildren, getGrandParent, getName, getNameRange, getNavpanelVisibility, getNavpanelVisibility, getNumber, getParent, getProperty, hasChildren, isFixed, isMarked, isScanning, isSelected, isWritable, makeValidName, makeValidName, notifyParentOfChange, postscan, printReferences, recursivelyContained, recursivelyContains, removeTempFlag, scan, setFixed, setFlag, setMarked, setName, setNavpanelVisibility, setNavpanelVisibility, setNumber, setParent, setScanning, setSelected, setWritable, write

Methods inherited from class java.lang.Object

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

Methods inherited from interface artisynth.core.modelbase.ModelComponent

connectToHierarchy, disconnectFromHierarchy, getName, getNavpanelVisibility, getNumber, getParent, isFixed, isMarked, isSelected, notifyParentOfChange, scan, setFixed, setMarked, setName, setNumber, setParent, setSelected, setWritable

Methods inherited from interface maspack.properties.HasProperties

getProperty

Methods inherited from interface maspack.properties.HierarchyNode

getChildren, hasChildren

Methods inherited from interface artisynth.core.modelbase.PostScannable

postscan

Methods inherited from interface maspack.util.Scannable

isWritable, write

Methods inherited from interface artisynth.core.modelbase.HasNumericState

advanceState, getAuxVarDerivative, getAuxVarState, getStateVersion, numAuxVars, requiresAdvance, setAuxVarState

Field Detail

DEFAULT_ENABLED

public static final boolean DEFAULT_ENABLED

See Also:

Constant Field Values

DEFAULT_FORCE_SCALE

public static final double DEFAULT_FORCE_SCALE

See Also:

Constant Field Values

DEFAULT_EXCITATION

public static final double DEFAULT_EXCITATION

See Also:

Constant Field Values

myProps

public static PropertyList myProps

Constructor Detail

JointActuator

public JointActuator()

No-args constructor needed for write/scan.

JointActuator

public JointActuator(java.lang.String name,
                     JointCoordinateHandle ch,
                     double forceScale)

Creates a named JointActuator from a specified coordinate handle.

Parameters:

name - name of the JointActuator (can be null)

ch - handle describing the coordinate and its joint

forceScale - excitation scale factor that determines the actual applied force

JointActuator

public JointActuator(JointCoordinateHandle ch,
                     double forceScale)

Creates an unnamed JointActuator from a specified coordinate handle.

Parameters:

ch - handle describing the coordinate and its joint

forceScale - excitation scale factor that determines the actual applied force

JointActuator

public JointActuator(java.lang.String name,
                     JointBase joint,
                     int idx,
                     double forceScale)

Creates a named JointActuator from a specified joint and coordinate index.

Parameters:

name - name of the JointActuator (can be null)

joint - joint containing the coordinate

idx - index of the coordinate within the joint

forceScale - excitation scale factor that determines the actual applied force

Method Detail

getAllPropertyInfo

public PropertyList getAllPropertyInfo()

Description copied from interface: HasProperties

Returns a list giving static information about all properties exported by this object.

Specified by:

getAllPropertyInfo in interface HasProperties

Overrides:

getAllPropertyInfo in class ModelComponentBase

Returns:

static information for all exported properties

getCoordinateHandle

public JointCoordinateHandle getCoordinateHandle()

Returns the handle for the coordinate/joint pair used by this JointActuator. Should not be modified.

Returns:

coordinate handle

isEnabled

public boolean isEnabled()

Queries whether this actuator is enabled.

Returns:

true if this actuator is enabled

setEnabled

public void setEnabled(boolean enabled)

Sets whether or not this actuator is enabled. A disabled actuator produces no force.

Parameters:

enabled - if true, enables this actuator

setForceScale

public void setForceScale(double s)

Sets the force scale associated with this JointActuator. The applied coordinate force is given by

 excitation * forceScale
 

Parameters:

s - force scale

getForceScale

public double getForceScale()

Queries the force scale associated with this JointActuator. See setForceScale(double).

Returns:

force scale

setExcitation

public void setExcitation(double e)

Sets the excitation associated with this JointActuator. The applied coordinate force is given by

 excitation * forceScale
 

Specified by:

setExcitation in interface ExcitationComponent

Parameters:

e - excitation value

getExcitation

public double getExcitation()

Queries the excitation associated with this JointActuator. See setExcitation(double).

Specified by:

getExcitation in interface ExcitationComponent

Returns:

excitation value

applyForces

public void applyForces(double t)

Adds forces to the components affected by this force effector at a particular time. Component forces should be added and not set, since other forces may be added to the same components by other force effectors.

Specified by:

applyForces in interface ForceEffector

Parameters:

t - time (seconds)

addSolveBlocks

public void addSolveBlocks(SparseNumberedBlockMatrix M)

Adds any needed blocks to a solve matrix in order to accomodate the Jacobian terms associated with this force effector. In general, blocks will be need to be added at locations given by the block indices (bi, bj), where bi and bj correspond to the solve indices (as returned by getSolveIndex) for all dynamic or attached components affected by this force effector.

Specified by:

addSolveBlocks in interface ForceEffector

Parameters:

M - solve matrix to which blocks should be added

addPosJacobian

public void addPosJacobian(SparseNumberedBlockMatrix M,
                           double s)

Scales the components of the position Jacobian associated with this force effector and adds it to the supplied solve matrix M.

M is guaranteed to be the same matrix supplied in the most recent call to addSolveBlocks, and so implementations may choose to cache the relevant matrix blocks from that call, instead of retrieving them directly from M.

Specified by:

addPosJacobian in interface ForceEffector

Parameters:

M - solve matrix to which scaled position Jacobian is to be added

s - scaling factor for position Jacobian

addVelJacobian

public void addVelJacobian(SparseNumberedBlockMatrix M,
                           double s)

Scales the components of the velocity Jacobian associated with this force effector and adds it to the supplied solve matrix M.

M is guaranteed to be the same matrix supplied in the most recent call to addSolveBlocks, and so implementations may choose to cache the relevant matrix blocks from that call, instead of retrieving them directly from M.

Specified by:

addVelJacobian in interface ForceEffector

Parameters:

M - solve matrix to which scaled velocity Jacobian is to be added

s - scaling factor for velocity Jacobian

getJacobianType

public int getJacobianType()

Returns a code indicating the matrix type that results when the Jacobian terms of this force effector are added to the solve matrix. This should be a logical or-ing of either Matrix.SYMMETRIC or Matrix.POSITIVE_DEFINITE. The former should be set if adding the Jacobian terms preserves symmetry, and the latter should be set if positive definiteness if preserved. Both should be set if there is no Jacobian for this effector (i.e., the Jacobian methods are not implemented). Matrix types from all the force effectors are logically and-ed together to determine the type for the entire solve matrix.

Specified by:

getJacobianType in interface ForceEffector

Returns:

solve matrix type resulting from adding Jacobian terms

getState

public void getState(DataBuffer data)

Saves state information for this component by adding data to the supplied DataBuffer. Existing data in the buffer should not be disturbed.

Specified by:

getState in interface HasNumericState

Parameters:

data - buffer for storing the state values.

setState

public void setState(DataBuffer data)

Restores the state for this component by reading from the supplied data buffer, starting at the current buffer offsets.

Specified by:

setState in interface HasNumericState

Parameters:

data - buffer containing the state information

hasState

public boolean hasState()

Queries if this component has state. Structure change events involving components that have state will cause the current state history of of the system to be cleared.

Specified by:

hasState in interface HasNumericState

Specified by:

hasState in interface ModelComponent

Overrides:

hasState in class ModelComponentBase

Returns:

true if this component has state

setCombinationRule

public void setCombinationRule(ExcitationComponent.CombinationRule rule)

Sets the rule for combining excitations.

Specified by:

setCombinationRule in interface ExcitationComponent

Parameters:

rule - rule for combining excitations

getCombinationRule

public ExcitationComponent.CombinationRule getCombinationRule()

Return the combination rule for excitations.

Specified by:

getCombinationRule in interface ExcitationComponent

Returns:

combination rule for excitations

addExcitationSource

public void addExcitationSource(ExcitationComponent ex,
                                double gain)

Adds a new excitation source to this Excitable with a specified gain.

Specified by:

addExcitationSource in interface ExcitationComponent

Parameters:

ex - excitatation source to be added

gain - gain for the source

setExcitationGain

public boolean setExcitationGain(ExcitationComponent ex,
                                 double gain)

Sets the gain for an excitation source in this component.

Specified by:

setExcitationGain in interface ExcitationComponent

Parameters:

ex - excitatation source whose gain is to be modified

gain - new gain for the source

Returns:

false if the source is not present in this component.

getExcitationGain

public double getExcitationGain(ExcitationComponent ex)

Gets the gain for an excitation source in this component.

Specified by:

getExcitationGain in interface ExcitationComponent

Parameters:

ex - excitatation source whose gain is to be queried

Returns:

source gain value, or -1 if the source is not present in this component.

removeExcitationSource

public boolean removeExcitationSource(ExcitationComponent ex)

Removes an excitation source from this Excitable. Returns false if the source was not present.

Specified by:

removeExcitationSource in interface ExcitationComponent

Parameters:

ex - excitatation source to be removed

Returns:

true if the source was present and removed

getNetExcitation

public double getNetExcitation()

Returns the net excitation for this Excitable. The net excitation is the combination of the primary excitation and the net excitations of all the excitation sources.

Specified by:

getNetExcitation in interface ExcitationComponent

Returns:

net excitation for this Excitable

updateReferences

public void updateReferences(boolean undo,
                             java.util.Deque<java.lang.Object> undoInfo)

May be called by the system if any of the soft references for this component are removed from the the component hierarchy. If called with undo equal to false, this component should then examine its soft references and use ComponentUtils.areConnected() to determine which of them have been disconnected from the hierarchy. Disconnected references should be removed, and sufficient information should be appended to undoInfo to allow this update to be undone if this method is called later with undo equal to true. When undoing an update, the undo information should be removed from the front of undoInfo.

Specified by:

updateReferences in interface ModelComponent

Overrides:

updateReferences in class ModelComponentBase

Parameters:

undo - if true, indicates that the most recent reference update should be undone, using the supplied undo information.

undoInfo - if undo is false, should be used to store information allowing the reference update to be undone. Otherwise, if undo is true, then this supplied information to undo the most recent update.

getSoftReferences

public void getSoftReferences(java.util.List<ModelComponent> refs)

Appends all soft references for this component to a list. References are other components, outside of this component's immediate ancestry, on which this component depends. For example, an ExcitationComponent may refer to one or more other ExcitationComponents to act as excitation sources. A soft reference is one which can be removed from the referring component. In particular, if any soft references for a component are deleted, then that component's updateReferences() method will be called to update its internal reference information.

Specified by:

getSoftReferences in interface ModelComponent

Overrides:

getSoftReferences in class ModelComponentBase

Parameters:

refs - list to which soft references are appended

getHardReferences

public void getHardReferences(java.util.List<ModelComponent> refs)

Appends all hard references for this component to a list. References are other components, outside of this component's immediate ancestry, on which this component depends. For example, an AxialSpring refers to two Point components as for it's end points. A hard reference is one which the referring component must have, and which if deleted, implies that the referring component should be deleted too.

Specified by:

getHardReferences in interface ModelComponent

Overrides:

getHardReferences in class ModelComponentBase

Parameters:

refs - list to which hard references are appended

createActuators

public static java.util.ArrayList<JointActuator> createActuators(MechModel mech,
                                                                 JointBase joint,
                                                                 double forceScale)

Creates a complete set of JointActuators for all coordinates associated with a specific joint.

Parameters:

mech - if non-null, adds the actuators to the MechModel's set of force effectors

joint - joint for which the actuators should be created

forceScale - force scale for each actuator

Returns:

list of the created exciters

scaleDistance

public void scaleDistance(double s)

Description copied from interface: ScalableUnits

Scales all distance coordinates.

Specified by:

scaleDistance in interface ScalableUnits

Parameters:

s - scaling factor

scaleMass

public void scaleMass(double s)

Description copied from interface: ScalableUnits

Scales all mass units.

Specified by:

scaleMass in interface ScalableUnits

Parameters:

s - scaling factor