artisynth.core.materials

Class PaiAxialMuscle

java.lang.Object

artisynth.core.materials.MaterialBase

artisynth.core.materials.AxialMaterial

artisynth.core.materials.AxialMuscleMaterialBase

artisynth.core.materials.AxialMuscleMaterial

artisynth.core.materials.PaiAxialMuscle

All Implemented Interfaces:

HasMaterialState, PostScannable, ScalableUnits, java.lang.Cloneable, CompositeProperty, HasProperties, Clonable, Scannable

public class PaiAxialMuscle
extends AxialMuscleMaterial

Field Summary

Fields inherited from class artisynth.core.materials.AxialMuscleMaterial

DEFAULT_DAMPING, DEFAULT_MAX_FORCE, DEFAULT_MAX_LENGTH, DEFAULT_OPT_LENGTH, DEFAULT_PASSIVE_FRACTION, DEFAULT_SCALING, DEFAULT_TENDON_RATIO, maxStretch, minStretch, myProps

Constructor Summary

Constructors

Constructor and Description
PaiAxialMuscle() Constructs a new PaiAxialMuscle.
PaiAxialMuscle(double fmax, double lopt, double lmax, double tratio, double pfrac) Deprecated. For historical reasons, this constructor sets the deprecated forceScaling property to 1000, thus scaling the effective value of fmax.
PaiAxialMuscle(double fmax, double lopt, double lmax, double tratio, double pfrac, double damping) Deprecated. For historical reasons, this constructor sets the deprecated forceScaling property to 1000, this scaling the effective values of fmax and damping.

Method Summary

Modifier and Type	Method and Description
double	computeDFdl(double l, double ldot, double l0, double ex) Computes and returns the derivative of the axial spring tension with respect to the length.
double	computeDFdldot(double l, double ldot, double l0, double ex) Computes and returns the derivative of the axial spring tension with respect to the length time derivative.
double	computeF(double l, double ldot, double l0, double ex) Computes and returns the axial spring tension, as a function of length, length time derivative, rest length, and excitation.
static PaiAxialMuscle	create() Creates a new PaiAxialMuscle with default values.
static PaiAxialMuscle	create(double fmax, double lopt, double lmax, double tratio, double pfrac) Creates a new PaiAxialMuscle with specified values.
static PaiAxialMuscle	create(double fmax, double lopt, double lmax, double tratio, double pfrac, double damping) Creates a new PaiAxialMuscle with specified values.
boolean	isDFdldotZero() Returns true if computeDFdldot() always returns zero.

Methods inherited from class artisynth.core.materials.AxialMuscleMaterial

clone, equals, getAllPropertyInfo, getDamping, getDampingMode, getForceScaling, getForceScalingMode, getMaxForce, getMaxForceMode, getMaxLength, getMaxLengthMode, getOptLength, getOptLengthMode, getPassiveFraction, getPassiveFractionMode, getSubClasses, getTendonRatio, getTendonRatioMode, normalizeForceScaling, scaleDistance, scaleMass, setAxialMuscleMaterialProps, setDamping, setDampingMode, setForceScaling, setForceScalingMode, setMaxForce, setMaxForceMode, setMaxLength, setMaxLengthMode, setOptLength, setOptLengthMode, setPassiveFraction, setPassiveFractionMode, setTendonRatio, setTendonRatioMode, toString

Methods inherited from class artisynth.core.materials.AxialMaterial

equals

Methods inherited from class artisynth.core.materials.MaterialBase

advanceState, createStateObject, getProperty, getPropertyHost, getPropertyInfo, hasProperty, hasState, hasSymmetricTangent, isWritable, postscan, scan, setPropertyHost, setPropertyInfo, symmetryOrStateChanged, updateMaterial, write, writeItems

Methods inherited from class java.lang.Object

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

Constructor Detail

PaiAxialMuscle

public PaiAxialMuscle()

Constructs a new PaiAxialMuscle.

Important: for historical reasons, this constructor sets the deprecated forceScaling property to 1000, thus scaling the effective values of the maxForce and damping properties.

PaiAxialMuscle

public PaiAxialMuscle(double fmax,
                      double lopt,
                      double lmax,
                      double tratio,
                      double pfrac)

Deprecated. For historical reasons, this constructor sets the deprecated forceScaling property to 1000, thus scaling the effective value of fmax.

Constructs a new PaiAxialMuscle with specified values. The damping parameter is set to 0.

Parameters:

fmax - maximum contractile force

lopt - length beyond which maximum active force is generated

lmax - length at which maximum passive force is generated

tratio - tendon to fibre length ratio

pfrac - passive fraction (of fmax) that forms the maximum passive force

PaiAxialMuscle

public PaiAxialMuscle(double fmax,
                      double lopt,
                      double lmax,
                      double tratio,
                      double pfrac,
                      double damping)

Deprecated. For historical reasons, this constructor sets the deprecated forceScaling property to 1000, this scaling the effective values of fmax and damping.

Constructs a new PaiAxialMuscle with specified values.

Parameters:

fmax - maximum contractile force

lopt - length beyond which maximum active force is generated

lmax - length at which maximum passive force is generated

tratio - tendon to fibre length ratio

pfrac - passive fraction (of fmax) that forms the maximum passive force

damping - damping parameter

Method Detail

create

public static PaiAxialMuscle create()

Creates a new PaiAxialMuscle with default values. The (deprecated) forceScaling property is set to 1.

Returns:

created material

create

public static PaiAxialMuscle create(double fmax,
                                    double lopt,
                                    double lmax,
                                    double tratio,
                                    double pfrac)

Creates a new PaiAxialMuscle with specified values. The damping property is set to 0 and the (deprecated) forceScaling property is set to 1.

Parameters:

fmax - maximum contractile force

lopt - length beyond which maximum active force is generated

lmax - length at which maximum passive force is generated

tratio - tendon to fibre length ratio

pfrac - passive fraction (of fmax) that forms the maximum passive force

Returns:

created material

create

public static PaiAxialMuscle create(double fmax,
                                    double lopt,
                                    double lmax,
                                    double tratio,
                                    double pfrac,
                                    double damping)

Creates a new PaiAxialMuscle with specified values. The (deprecated) forceScaling property is set to 1.

Parameters:

fmax - maximum contractile force

lopt - length beyond which maximum active force is generated

lmax - length at which maximum passive force is generated

tratio - tendon to fibre length ratio

pfrac - passive fraction (of fmax) that forms the maximum passive force

damping - damping parameter

Returns:

created material

computeF

public double computeF(double l,
                       double ldot,
                       double l0,
                       double ex)

Description copied from class: AxialMaterial

Computes and returns the axial spring tension, as a function of length, length time derivative, rest length, and excitation.

Specified by:

computeF in class AxialMaterial

Parameters:

l - spring length

ldot - spring length time derivative

l0 - spring rest length

ex - excitation value (varying from 0 to 1)

Returns:

spring tension

computeDFdl

public double computeDFdl(double l,
                          double ldot,
                          double l0,
                          double ex)

Description copied from class: AxialMaterial

Computes and returns the derivative of the axial spring tension with respect to the length.

Specified by:

computeDFdl in class AxialMaterial

Parameters:

l - spring length

ldot - spring length time derivative

l0 - spring rest length

ex - excitation value (varying from 0 to 1)

Returns:

tension derivative with respect to length

computeDFdldot

public double computeDFdldot(double l,
                             double ldot,
                             double l0,
                             double ex)

Description copied from class: AxialMaterial

Computes and returns the derivative of the axial spring tension with respect to the length time derivative.

Specified by:

computeDFdldot in class AxialMaterial

Parameters:

l - spring length

ldot - spring length time derivative

l0 - spring rest length

ex - excitation value (varying from 0 to 1)

Returns:

tension derivative with respect to length time derivative

isDFdldotZero

public boolean isDFdldotZero()

Description copied from class: AxialMaterial

Returns true if computeDFdldot() always returns zero. For a linear spring, this simply means the damping is zero. When dFdldot is always 0, then stiffness matrix will be symmetric.

Specified by:

isDFdldotZero in class AxialMaterial