API  4.3
For MATLAB, Python, Java, and C++ users
OpenSim::Millard2012AccelerationMuscle Class Reference


This class implements a 3 state (activation,fiber length and fiber velocity) acceleration musculo-tendon model that has several advantages over equilibrium musculo-tendon models: it is possible to simulate 0 activation, it requires fewer integrator steps to simulate, and physiological active force-length (with a minimum value of 0) and force velocity (with true asymptotes at the maximum shortening and lengthening velocities) curves can be employed. More...

+ Inheritance diagram for OpenSim::Millard2012AccelerationMuscle:

OpenSim Properties, Sockets, Outputs, Inputs

Properties (single-value)
double default_activation
 "assumed initial activation level if none is assigned." More...
 
double default_fiber_length
 "assumed initial fiber length if none is assigned." More...
 
double default_fiber_velocity
 "assumed initial fiber velocity if none is assigned." More...
 
double fiber_damping
 "fiber damping coefficient" More...
 
double fiber_force_length_damping
 "fiber force length damping coefficient" More...
 
double fiber_compressive_force_length_damping
 "fiber compressive force length damping coefficient" More...
 
double fiber_compressive_force_cos_pennation_damping
 "fiber compressive force cos(pennationAngle) damping coefficient" More...
 
double tendon_force_length_damping
 "tendon force length damping coefficient" More...
 
double mass
 "lumped mass" More...
 
Properties (unnamed)
MuscleFirstOrderActivationDynamicModel MuscleFirstOrderActivationDynamicModel
 "activation dynamics model with a lower bound" More...
 
ActiveForceLengthCurve ActiveForceLengthCurve
 "active force length curve" More...
 
ForceVelocityCurve ForceVelocityCurve
 "force velocity curve" More...
 
FiberForceLengthCurve FiberForceLengthCurve
 "fiber force length curve" More...
 
TendonForceLengthCurve TendonForceLengthCurve
 "Tendon force length curve" More...
 
FiberCompressiveForceLengthCurve FiberCompressiveForceLengthCurve
 "fiber compressive force length curve" More...
 
FiberCompressiveForceCosPennationCurve FiberCompressiveForceCosPennationCurve
 "fiber compressive force cos(pennationAngle) curve" More...
 
- OpenSim Properties, Sockets, Outputs, Inputs inherited from OpenSim::Muscle
double max_isometric_force
 "Maximum isometric force that the fibers can generate" More...
 
double optimal_fiber_length
 "Optimal length of the muscle fibers" More...
 
double tendon_slack_length
 "Resting length of the tendon" More...
 
double pennation_angle_at_optimal
 "Angle between tendon and fibers at optimal fiber length expressed in radians" More...
 
double max_contraction_velocity
 "Maximum contraction velocity of the fibers, in optimal fiberlengths/second" More...
 
bool ignore_tendon_compliance
 "Compute muscle dynamics ignoring tendon compliance. Tendon is assumed to be rigid." More...
 
bool ignore_activation_dynamics
 "Compute muscle dynamics ignoring activation dynamics. Activation is equivalent to excitation." More...
 
double excitation
 Provides the value of getExcitation() and is available at stage SimTK::Stage::Dynamics . More...
 
double activation
 Provides the value of getActivation() and is available at stage SimTK::Stage::Dynamics . More...
 
double fiber_length
 Provides the value of getFiberLength() and is available at stage SimTK::Stage::Position . More...
 
double pennation_angle
 Provides the value of getPennationAngle() and is available at stage SimTK::Stage::Position . More...
 
double cos_pennation_angle
 Provides the value of getCosPennationAngle() and is available at stage SimTK::Stage::Position . More...
 
double tendon_length
 Provides the value of getTendonLength() and is available at stage SimTK::Stage::Position . More...
 
double normalized_fiber_length
 Provides the value of getNormalizedFiberLength() and is available at stage SimTK::Stage::Position . More...
 
double fiber_length_along_tendon
 Provides the value of getFiberLengthAlongTendon() and is available at stage SimTK::Stage::Position . More...
 
double tendon_strain
 Provides the value of getTendonStrain() and is available at stage SimTK::Stage::Position . More...
 
double passive_force_multiplier
 Provides the value of getPassiveForceMultiplier() and is available at stage SimTK::Stage::Position . More...
 
double active_force_length_multiplier
 Provides the value of getActiveForceLengthMultiplier() and is available at stage SimTK::Stage::Position . More...
 
double fiber_velocity
 Provides the value of getFiberVelocity() and is available at stage SimTK::Stage::Velocity . More...
 
double normalized_fiber_velocity
 Provides the value of getNormalizedFiberVelocity() and is available at stage SimTK::Stage::Velocity . More...
 
double fiber_velocity_along_tendon
 Provides the value of getFiberVelocityAlongTendon() and is available at stage SimTK::Stage::Velocity . More...
 
double tendon_velocity
 Provides the value of getTendonVelocity() and is available at stage SimTK::Stage::Velocity . More...
 
double force_velocity_multiplier
 Provides the value of getForceVelocityMultiplier() and is available at stage SimTK::Stage::Velocity . More...
 
double pennation_angular_velocity
 Provides the value of getPennationAngularVelocity() and is available at stage SimTK::Stage::Velocity . More...
 
double fiber_force
 Provides the value of getFiberForce() and is available at stage SimTK::Stage::Dynamics . More...
 
double fiber_force_along_tendon
 Provides the value of getFiberForceAlongTendon() and is available at stage SimTK::Stage::Dynamics . More...
 
double active_fiber_force
 Provides the value of getActiveFiberForce() and is available at stage SimTK::Stage::Dynamics . More...
 
double passive_fiber_force
 Provides the value of getPassiveFiberForce() and is available at stage SimTK::Stage::Dynamics . More...
 
double active_fiber_force_along_tendon
 Provides the value of getActiveFiberForceAlongTendon() and is available at stage SimTK::Stage::Dynamics . More...
 
double passive_fiber_force_along_tendon
 Provides the value of getPassiveFiberForceAlongTendon() and is available at stage SimTK::Stage::Dynamics . More...
 
double tendon_force
 Provides the value of getTendonForce() and is available at stage SimTK::Stage::Dynamics . More...
 
double fiber_stiffness
 Provides the value of getFiberStiffness() and is available at stage SimTK::Stage::Dynamics . More...
 
double fiber_stiffness_along_tendon
 Provides the value of getFiberStiffnessAlongTendon() and is available at stage SimTK::Stage::Dynamics . More...
 
double tendon_stiffness
 Provides the value of getTendonStiffness() and is available at stage SimTK::Stage::Dynamics . More...
 
double muscle_stiffness
 Provides the value of getMuscleStiffness() and is available at stage SimTK::Stage::Dynamics . More...
 
double fiber_active_power
 Provides the value of getFiberActivePower() and is available at stage SimTK::Stage::Dynamics . More...
 
double fiber_passive_power
 Provides the value of getFiberPassivePower() and is available at stage SimTK::Stage::Dynamics . More...
 
double tendon_power
 Provides the value of getTendonPower() and is available at stage SimTK::Stage::Dynamics . More...
 
double muscle_power
 Provides the value of getMusclePower() and is available at stage SimTK::Stage::Dynamics . More...
 
- OpenSim Properties, Sockets, Outputs, Inputs inherited from OpenSim::PathActuator
GeometryPath GeometryPath
 "The set of points defining the path of the actuator." More...
 
double optimal_force
 "The maximum force this actuator can produce." More...
 
double tension
 Provides the value of computeActuation() and is available at stage SimTK::Stage::Acceleration . More...
 
- OpenSim Properties, Sockets, Outputs, Inputs inherited from OpenSim::ScalarActuator
double min_control
 "Minimum allowed value for control signal. Used primarily when solving " "for control values." More...
 
double max_control
 "Maximum allowed value for control signal. Used primarily when solving " "for control values." More...
 
double actuation
 Provides the value of getActuation() and is available at stage SimTK::Stage::Velocity . More...
 
double speed
 Provides the value of getSpeed() and is available at stage SimTK::Stage::Velocity . More...
 
- OpenSim Properties, Sockets, Outputs, Inputs inherited from OpenSim::Actuator
double power
 Provides the value of getPower() and is available at stage SimTK::Stage::Dynamics . More...
 
- OpenSim Properties, Sockets, Outputs, Inputs inherited from OpenSim::Force
bool appliesForce
 "Flag indicating whether the force is applied or not. If true the force" "is applied to the MultibodySystem otherwise the force is not applied." "NOTE: Prior to OpenSim 4.0, this behavior was controlled by the " "'isDisabled' property, where 'true' meant that force was not being " "applied. Thus, if 'isDisabled' is true, then 'appliesForce` is false." More...
 
double potential_energy
 Provides the value of computePotentialEnergy() and is available at stage SimTK::Stage::Velocity . More...
 
- OpenSim Properties, Sockets, Outputs, Inputs inherited from OpenSim::Component
Component components
 "List of components that this component owns and serializes." More...
 

Public Member Functions

 Millard2012AccelerationMuscle ()
 Default constructor: produces a non-functional empty muscle. More...
 
 Millard2012AccelerationMuscle (const std::string &aName, double aMaxIsometricForce, double aOptimalFiberLength, double aTendonSlackLength, double aPennationAngle)
 Constructs a functional muscle using all of the default curves and activation model. More...
 
double getFiberCompressiveForceLengthMultiplier (SimTK::State &s) const
 
More...
 
double getFiberCompressiveForceCosPennationMultiplier (SimTK::State &s) const
 
More...
 
double getTendonForceMultiplier (SimTK::State &s) const
 
More...
 
double getMass () const
 
More...
 
const MuscleFirstOrderActivationDynamicModelgetActivationModel () const
 
More...
 
const MuscleFixedWidthPennationModelgetPennationModel () const
 
More...
 
const ActiveForceLengthCurvegetActiveForceLengthCurve () const
 
More...
 
const ForceVelocityCurvegetForceVelocityCurve () const
 
More...
 
const FiberForceLengthCurvegetFiberForceLengthCurve () const
 
More...
 
const TendonForceLengthCurvegetTendonForceLengthCurve () const
 
More...
 
const FiberCompressiveForceLengthCurvegetFiberCompressiveForceLengthCurve () const
 
More...
 
const FiberCompressiveForceCosPennationCurvegetFiberCompressiveForceCosPennationCurve () const
 
More...
 
double getFiberStiffnessAlongTendon (const SimTK::State &s) const
 
More...
 
void setActivationModel (MuscleFirstOrderActivationDynamicModel &aActivationMdl)
 
More...
 
void setActiveForceLengthCurve (ActiveForceLengthCurve &aActiveForceLengthCurve)
 
More...
 
void setForceVelocityCurve (ForceVelocityCurve &aForceVelocityCurve)
 
More...
 
void setFiberForceLengthCurve (FiberForceLengthCurve &aFiberForceLengthCurve)
 
More...
 
void setTendonForceLengthCurve (TendonForceLengthCurve &aTendonForceLengthCurve)
 
More...
 
void setFiberCompressiveForceLengthCurve (FiberCompressiveForceLengthCurve &aFiberCompressiveForceLengthCurve)
 
More...
 
void setFiberCompressiveForceCosPennationCurve (FiberCompressiveForceCosPennationCurve &aFiberCompressiveForceCosPennationCurve)
 
More...
 
void setMass (double mass)
 
More...
 
double getDefaultActivation () const
 
More...
 
double getDefaultFiberLength () const
 
More...
 
double getDefaultFiberVelocity () const
 
More...
 
double getActivationRate (const SimTK::State &s) const
 
More...
 
double getFiberVelocity (const SimTK::State &s) const
 
More...
 
double getFiberAcceleration (const SimTK::State &s) const
 
More...
 
void setDefaultActivation (double activation)
 
More...
 
void setDefaultFiberLength (double fiberLength)
 
More...
 
void setDefaultFiberVelocity (double fiberVelocity)
 
More...
 
void setActivation (SimTK::State &s, double activation) const override
 
More...
 
void setFiberLength (SimTK::State &s, double fiberLength) const
 
More...
 
void setFiberVelocity (SimTK::State &s, double fiberVelocity) const
 
More...
 
double computeActuation (const SimTK::State &s) const override final
 
More...
 
void computeInitialFiberEquilibrium (SimTK::State &s) const override final
 This function computes the fiber length such that muscle fiber and tendon are developing the same force, and so that the velocity of the entire muscle-tendon is spread between the fiber and the tendon according to their relative compliances. More...
 
void extendPostScale (const SimTK::State &s, const ScaleSet &scaleSet) override
 Adjust the properties of the muscle after the model has been scaled. More...
 
Property-related functions
const double & get_default_activation () const
 Get the value of the default_activation property. More...
 
double & upd_default_activation ()
 Get a writable reference to the default_activation property. More...
 
void set_default_activation (const double &value)
 Set the value of the default_activation property. More...
 
const double & get_default_fiber_length () const
 Get the value of the default_fiber_length property. More...
 
double & upd_default_fiber_length ()
 Get a writable reference to the default_fiber_length property. More...
 
void set_default_fiber_length (const double &value)
 Set the value of the default_fiber_length property. More...
 
const double & get_default_fiber_velocity () const
 Get the value of the default_fiber_velocity property. More...
 
double & upd_default_fiber_velocity ()
 Get a writable reference to the default_fiber_velocity property. More...
 
void set_default_fiber_velocity (const double &value)
 Set the value of the default_fiber_velocity property. More...
 
const MuscleFirstOrderActivationDynamicModelget_MuscleFirstOrderActivationDynamicModel () const
 Get the value of the MuscleFirstOrderActivationDynamicModel property. More...
 
MuscleFirstOrderActivationDynamicModelupd_MuscleFirstOrderActivationDynamicModel ()
 Get a writable reference to the MuscleFirstOrderActivationDynamicModel property. More...
 
void set_MuscleFirstOrderActivationDynamicModel (const MuscleFirstOrderActivationDynamicModel &value)
 Set the value of the MuscleFirstOrderActivationDynamicModel property. More...
 
const ActiveForceLengthCurveget_ActiveForceLengthCurve () const
 Get the value of the ActiveForceLengthCurve property. More...
 
ActiveForceLengthCurveupd_ActiveForceLengthCurve ()
 Get a writable reference to the ActiveForceLengthCurve property. More...
 
void set_ActiveForceLengthCurve (const ActiveForceLengthCurve &value)
 Set the value of the ActiveForceLengthCurve property. More...
 
const ForceVelocityCurveget_ForceVelocityCurve () const
 Get the value of the ForceVelocityCurve property. More...
 
ForceVelocityCurveupd_ForceVelocityCurve ()
 Get a writable reference to the ForceVelocityCurve property. More...
 
void set_ForceVelocityCurve (const ForceVelocityCurve &value)
 Set the value of the ForceVelocityCurve property. More...
 
const FiberForceLengthCurveget_FiberForceLengthCurve () const
 Get the value of the FiberForceLengthCurve property. More...
 
FiberForceLengthCurveupd_FiberForceLengthCurve ()
 Get a writable reference to the FiberForceLengthCurve property. More...
 
void set_FiberForceLengthCurve (const FiberForceLengthCurve &value)
 Set the value of the FiberForceLengthCurve property. More...
 
const TendonForceLengthCurveget_TendonForceLengthCurve () const
 Get the value of the TendonForceLengthCurve property. More...
 
TendonForceLengthCurveupd_TendonForceLengthCurve ()
 Get a writable reference to the TendonForceLengthCurve property. More...
 
void set_TendonForceLengthCurve (const TendonForceLengthCurve &value)
 Set the value of the TendonForceLengthCurve property. More...
 
const FiberCompressiveForceLengthCurveget_FiberCompressiveForceLengthCurve () const
 Get the value of the FiberCompressiveForceLengthCurve property. More...
 
FiberCompressiveForceLengthCurveupd_FiberCompressiveForceLengthCurve ()
 Get a writable reference to the FiberCompressiveForceLengthCurve property. More...
 
void set_FiberCompressiveForceLengthCurve (const FiberCompressiveForceLengthCurve &value)
 Set the value of the FiberCompressiveForceLengthCurve property. More...
 
const FiberCompressiveForceCosPennationCurveget_FiberCompressiveForceCosPennationCurve () const
 Get the value of the FiberCompressiveForceCosPennationCurve property. More...
 
FiberCompressiveForceCosPennationCurveupd_FiberCompressiveForceCosPennationCurve ()
 Get a writable reference to the FiberCompressiveForceCosPennationCurve property. More...
 
void set_FiberCompressiveForceCosPennationCurve (const FiberCompressiveForceCosPennationCurve &value)
 Set the value of the FiberCompressiveForceCosPennationCurve property. More...
 
const double & get_fiber_damping () const
 Get the value of the fiber_damping property. More...
 
double & upd_fiber_damping ()
 Get a writable reference to the fiber_damping property. More...
 
void set_fiber_damping (const double &value)
 Set the value of the fiber_damping property. More...
 
const double & get_fiber_force_length_damping () const
 Get the value of the fiber_force_length_damping property. More...
 
double & upd_fiber_force_length_damping ()
 Get a writable reference to the fiber_force_length_damping property. More...
 
void set_fiber_force_length_damping (const double &value)
 Set the value of the fiber_force_length_damping property. More...
 
const double & get_fiber_compressive_force_length_damping () const
 Get the value of the fiber_compressive_force_length_damping property. More...
 
double & upd_fiber_compressive_force_length_damping ()
 Get a writable reference to the fiber_compressive_force_length_damping property. More...
 
void set_fiber_compressive_force_length_damping (const double &value)
 Set the value of the fiber_compressive_force_length_damping property. More...
 
const double & get_fiber_compressive_force_cos_pennation_damping () const
 Get the value of the fiber_compressive_force_cos_pennation_damping property. More...
 
double & upd_fiber_compressive_force_cos_pennation_damping ()
 Get a writable reference to the fiber_compressive_force_cos_pennation_damping property. More...
 
void set_fiber_compressive_force_cos_pennation_damping (const double &value)
 Set the value of the fiber_compressive_force_cos_pennation_damping property. More...
 
const double & get_tendon_force_length_damping () const
 Get the value of the tendon_force_length_damping property. More...
 
double & upd_tendon_force_length_damping ()
 Get a writable reference to the tendon_force_length_damping property. More...
 
void set_tendon_force_length_damping (const double &value)
 Set the value of the tendon_force_length_damping property. More...
 
const double & get_mass () const
 Get the value of the mass property. More...
 
double & upd_mass ()
 Get a writable reference to the mass property. More...
 
void set_mass (const double &value)
 Set the value of the mass property. More...
 
- Public Member Functions inherited from OpenSim::Muscle
const double & get_max_isometric_force () const
 Get the value of the max_isometric_force property. More...
 
double & upd_max_isometric_force ()
 Get a writable reference to the max_isometric_force property. More...
 
void set_max_isometric_force (const double &value)
 Set the value of the max_isometric_force property. More...
 
const double & get_optimal_fiber_length () const
 Get the value of the optimal_fiber_length property. More...
 
double & upd_optimal_fiber_length ()
 Get a writable reference to the optimal_fiber_length property. More...
 
void set_optimal_fiber_length (const double &value)
 Set the value of the optimal_fiber_length property. More...
 
const double & get_tendon_slack_length () const
 Get the value of the tendon_slack_length property. More...
 
double & upd_tendon_slack_length ()
 Get a writable reference to the tendon_slack_length property. More...
 
void set_tendon_slack_length (const double &value)
 Set the value of the tendon_slack_length property. More...
 
const double & get_pennation_angle_at_optimal () const
 Get the value of the pennation_angle_at_optimal property. More...
 
double & upd_pennation_angle_at_optimal ()
 Get a writable reference to the pennation_angle_at_optimal property. More...
 
void set_pennation_angle_at_optimal (const double &value)
 Set the value of the pennation_angle_at_optimal property. More...
 
const double & get_max_contraction_velocity () const
 Get the value of the max_contraction_velocity property. More...
 
double & upd_max_contraction_velocity ()
 Get a writable reference to the max_contraction_velocity property. More...
 
void set_max_contraction_velocity (const double &value)
 Set the value of the max_contraction_velocity property. More...
 
const bool & get_ignore_tendon_compliance () const
 Get the value of the ignore_tendon_compliance property. More...
 
bool & upd_ignore_tendon_compliance ()
 Get a writable reference to the ignore_tendon_compliance property. More...
 
void set_ignore_tendon_compliance (const bool &value)
 Set the value of the ignore_tendon_compliance property. More...
 
const bool & get_ignore_activation_dynamics () const
 Get the value of the ignore_activation_dynamics property. More...
 
bool & upd_ignore_activation_dynamics ()
 Get a writable reference to the ignore_activation_dynamics property. More...
 
void set_ignore_activation_dynamics (const bool &value)
 Set the value of the ignore_activation_dynamics property. More...
 
 Muscle ()
 Default constructor. More...
 
double getMaxIsometricForce () const
 get/set the maximum isometric force (in N) that the fibers can generate More...
 
void setMaxIsometricForce (double maxIsometricForce)
 
double getOptimalFiberLength () const
 get/set the optimal length (in m) of the muscle fibers (lumped as a single fiber) More...
 
void setOptimalFiberLength (double optimalFiberLength)
 
double getTendonSlackLength () const
 get/set the resting (slack) length (in m) of the tendon that is in series with the muscle fiber More...
 
void setTendonSlackLength (double tendonSlackLength)
 
double getPennationAngleAtOptimalFiberLength () const
 get/set the angle (in radians) between fibers at their optimal fiber length and the tendon More...
 
void setPennationAngleAtOptimalFiberLength (double pennationAngle)
 
double getMaxContractionVelocity () const
 get/set the maximum contraction velocity of the fibers, in optimal fiber-lengths per second More...
 
void setMaxContractionVelocity (double maxContractionVelocity)
 
bool getIgnoreTendonCompliance (const SimTK::State &s) const
 Get/set Modeling (runtime) option to ignore tendon compliance when computing muscle dynamics. More...
 
void setIgnoreTendonCompliance (SimTK::State &s, bool ignore) const
 
bool getIgnoreActivationDynamics (const SimTK::State &s) const
 Get/set Modeling (runtime) option to ignore activation dynamics when computing muscle dynamics. More...
 
void setIgnoreActivationDynamics (SimTK::State &s, bool ignore) const
 
virtual double getActivation (const SimTK::State &s) const
 get the activation level of the muscle, which modulates the active force of the muscle and has a normalized (0 to 1) value Note: method remains virtual to permit override by deprecated muscles. More...
 
double getFiberLength (const SimTK::State &s) const
 get the current working fiber length (m) for the muscle More...
 
double getPennationAngle (const SimTK::State &s) const
 get the current pennation angle (radians) between the fiber and tendon at the current fiber length More...
 
double getCosPennationAngle (const SimTK::State &s) const
 get the cosine of the current pennation angle (radians) between the fiber and tendon at the current fiber length More...
 
double getTendonLength (const SimTK::State &s) const
 get the current tendon length (m) given the current joint angles and fiber length More...
 
double getNormalizedFiberLength (const SimTK::State &s) const
 get the current normalized fiber length (fiber_length/optimal_fiber_length) More...
 
double getFiberLengthAlongTendon (const SimTK::State &s) const
 get the current fiber length (m) projected (*cos(pennationAngle)) onto the tendon direction More...
 
double getTendonStrain (const SimTK::State &s) const
 get the current tendon strain (delta_l/tendon_slack_length is dimensionless) More...
 
double getFiberPotentialEnergy (const SimTK::State &s) const
 the potential energy (J) stored in the fiber due to its parallel elastic element More...
 
double getTendonPotentialEnergy (const SimTK::State &s) const
 the potential energy (J) stored in the tendon More...
 
double getMusclePotentialEnergy (const SimTK::State &s) const
 the total potential energy (J) stored in the muscle More...
 
double getPassiveForceMultiplier (const SimTK::State &s) const
 get the passive fiber (parallel elastic element) force multiplier More...
 
double getActiveForceLengthMultiplier (const SimTK::State &s) const
 get the active fiber (contractile element) force multiplier due to current fiber length More...
 
double getFiberVelocity (const SimTK::State &s) const
 get current fiber velocity (m/s) positive is lengthening More...
 
double getNormalizedFiberVelocity (const SimTK::State &s) const
 get normalized fiber velocity. More...
 
double getFiberVelocityAlongTendon (const SimTK::State &s) const
 get the current fiber velocity (m/s) projected onto the tendon direction More...
 
double getPennationAngularVelocity (const SimTK::State &s) const
 get pennation angular velocity (radians/s) More...
 
double getTendonVelocity (const SimTK::State &s) const
 get the tendon velocity (m/s) positive is lengthening More...
 
double getForceVelocityMultiplier (const SimTK::State &s) const
 get the dimensionless multiplier resulting from the fiber's force-velocity curve More...
 
double getFiberForce (const SimTK::State &s) const
 get the current fiber force (N) applied to the tendon More...
 
double getFiberForceAlongTendon (const SimTK::State &s) const
 get the force of the fiber (N/m) along the direction of the tendon More...
 
double getActiveFiberForce (const SimTK::State &s) const
 get the current active fiber force (N) due to activation*force_length*force_velocity relationships More...
 
double getPassiveFiberForce (const SimTK::State &s) const
 get the total force applied by all passive elements in the fiber (N) More...
 
double getActiveFiberForceAlongTendon (const SimTK::State &s) const
 get the current active fiber force (N) projected onto the tendon direction More...
 
double getPassiveFiberForceAlongTendon (const SimTK::State &s) const
 get the total force applied by all passive elements in the fiber (N) projected onto the tendon direction More...
 
double getTendonForce (const SimTK::State &s) const
 get the current tendon force (N) applied to bones More...
 
double getFiberStiffness (const SimTK::State &s) const
 get the current fiber stiffness (N/m) defined as the partial derivative of fiber force with respect to fiber length More...
 
double getFiberStiffnessAlongTendon (const SimTK::State &s) const
 get the stiffness of the fiber (N/m) along the direction of the tendon, that is the partial derivative of the fiber force along the tendon with respect to small changes in fiber length along the tendon More...
 
double getTendonStiffness (const SimTK::State &s) const
 get the current tendon stiffness (N/m) defined as the partial derivative of tendon force with respect to tendon length More...
 
double getMuscleStiffness (const SimTK::State &s) const
 get the current muscle stiffness (N/m) defined as the partial derivative of muscle force with respect to muscle length More...
 
double getFiberActivePower (const SimTK::State &s) const
 get the current active fiber power (W) More...
 
double getFiberPassivePower (const SimTK::State &s) const
 get the current passive fiber power (W) More...
 
double getTendonPower (const SimTK::State &s) const
 get the current tendon power (W) More...
 
double getMusclePower (const SimTK::State &s) const
 get the current muscle power (W) More...
 
double getStress (const SimTK::State &s) const override
 get the stress in the muscle (part of the Actuator interface as well) More...
 
void setExcitation (SimTK::State &s, double excitation) const
 set the excitation (control) for this muscle. More...
 
double getExcitation (const SimTK::State &s) const
 
void computeEquilibrium (SimTK::State &s) const override final
 Find and set the equilibrium state of the muscle (if any) More...
 
- Public Member Functions inherited from OpenSim::PathActuator
 PathActuator ()
 
GeometryPathupdGeometryPath ()
 
const GeometryPathgetGeometryPath () const
 
bool hasGeometryPath () const override
 Return a flag indicating whether the Force is applied along a Path. More...
 
void setOptimalForce (double aOptimalForce)
 
double getOptimalForce () const override
 
virtual double getLength (const SimTK::State &s) const
 
virtual double getLengtheningSpeed (const SimTK::State &s) const
 
double getPower (const SimTK::State &s) const override
 
double getStress (const SimTK::State &s) const override
 
void addNewPathPoint (const std::string &proposedName, const PhysicalFrame &aBody, const SimTK::Vec3 &aPositionOnBody)
 Note that this function does not maintain the State and so should be used only before a valid State is created. More...
 
double computeActuation (const SimTK::State &s) const override
 
virtual double computeMomentArm (const SimTK::State &s, Coordinate &aCoord) const
 
const GeometryPathget_GeometryPath () const
 Get the value of the GeometryPath property. More...
 
GeometryPathupd_GeometryPath ()
 Get a writable reference to the GeometryPath property. More...
 
void set_GeometryPath (const GeometryPath &value)
 Set the value of the GeometryPath property. More...
 
const double & get_optimal_force () const
 Get the value of the optimal_force property. More...
 
double & upd_optimal_force ()
 Get a writable reference to the optimal_force property. More...
 
void set_optimal_force (const double &value)
 Set the value of the optimal_force property. More...
 
PathActuatorclone () const override
 Create a new heap-allocated copy of the concrete object to which this Object refers. More...
 
const std::string & getConcreteClassName () const override
 Returns the class name of the concrete Object-derived class of the actual object referenced by this Object, as a string. More...
 
- Public Member Functions inherited from OpenSim::ScalarActuator
 ScalarActuator ()
 
virtual double getControl (const SimTK::State &s) const
 Convenience method to get control given scalar (double) valued control. More...
 
int numControls () const override
 
virtual void setActuation (const SimTK::State &s, double aActuation) const
 
virtual double getActuation (const SimTK::State &s) const
 
virtual void setSpeed (const SimTK::State &s, double aspeed) const
 
virtual double getSpeed (const SimTK::State &s) const
 
void setMinControl (const double &aMinControl)
 Methods to manage the bounds on ScalarActuator's control. More...
 
double getMinControl () const
 
void setMaxControl (const double &aMaxControl)
 
double getMaxControl () const
 
void overrideActuation (SimTK::State &s, bool flag) const
 Enable/disable a ScalarActuator's override actuation. More...
 
bool isActuationOverridden (const SimTK::State &s) const
 return ScalarActuator's override status More...
 
void setOverrideActuation (SimTK::State &s, double value) const
 set the actuation value used when the override is true More...
 
double getOverrideActuation (const SimTK::State &s) const
 return override actuation More...
 
const double & get_min_control () const
 Get the value of the min_control property. More...
 
double & upd_min_control ()
 Get a writable reference to the min_control property. More...
 
void set_min_control (const double &value)
 Set the value of the min_control property. More...
 
const double & get_max_control () const
 Get the value of the max_control property. More...
 
double & upd_max_control ()
 Get a writable reference to the max_control property. More...
 
void set_max_control (const double &value)
 Set the value of the max_control property. More...
 
- Public Member Functions inherited from OpenSim::Actuator
 Actuator ()
 
virtual const SimTK::Vector getDefaultControls ()
 Actuator default controls are zero. More...
 
virtual const SimTK::VectorView_< double > getControls (const SimTK::State &s) const
 
virtual void getControls (const SimTK::Vector &modelControls, SimTK::Vector &actuatorControls) const
 Convenience methods for getting, setting and adding to actuator controls from/into the model controls. More...
 
virtual void setControls (const SimTK::Vector &actuatorControls, SimTK::Vector &modelControls) const
 set actuator controls subvector into the right slot in the system-wide model controls More...
 
virtual void addInControls (const SimTK::Vector &actuatorControls, SimTK::Vector &modelControls) const
 add actuator controls to the values already occupying the slot in the system-wide model controls More...
 
- Public Member Functions inherited from OpenSim::Force
virtual bool shouldBeParallelized () const
 Tell SimBody to parallelize this force. More...
 
bool appliesForce (const SimTK::State &s) const
 Return if the Force is applied (or enabled) or not. More...
 
void setAppliesForce (SimTK::State &s, bool applyForce) const
 Set whether or not the Force is applied. More...
 
const bool & get_appliesForce () const
 Get the value of the appliesForce property. More...
 
bool & upd_appliesForce ()
 Get a writable reference to the appliesForce property. More...
 
void set_appliesForce (const bool &value)
 Set the value of the appliesForce property. More...
 
- Public Member Functions inherited from OpenSim::ModelComponent
 ModelComponent ()
 Default constructor. More...
 
 ModelComponent (const std::string &aFileName, bool aUpdateFromXMLNode=true)
 Construct ModelComponent from an XML file. More...
 
 ModelComponent (SimTK::Xml::Element &aNode)
 Construct ModelComponent from a specific node in an XML document. More...
 
virtual ~ModelComponent ()
 Destructor is virtual to allow concrete model component cleanup. More...
 
void connectToModel (Model &model)
 Connect this ModelComponent to its aggregate- a Model. More...
 
const ModelgetModel () const
 Get a const reference to the Model this component is part of. More...
 
ModelupdModel ()
 Get a modifiable reference to the Model this component is part of. More...
 
bool hasModel () const
 Does this ModelComponent have a Model associated with it? More...
 
void preScale (const SimTK::State &s, const ScaleSet &scaleSet)
 Perform any computations that must occur before ModelComponent::scale() is invoked on all ModelComponents in the Model. More...
 
void scale (const SimTK::State &s, const ScaleSet &scaleSet)
 Scale the ModelComponent. More...
 
void postScale (const SimTK::State &s, const ScaleSet &scaleSet)
 Perform any computations that must occur after ModelComponent::scale() has been invoked on all ModelComponents in the Model. More...
 
- Public Member Functions inherited from OpenSim::Component
 Component ()
 Default constructor. More...
 
 Component (const std::string &aFileName, bool aUpdateFromXMLNode=true)
 Construct Component from an XML file. More...
 
 Component (SimTK::Xml::Element &aNode)
 Construct Component from a specific node in an XML document. More...
 
 Component (const Component &)=default
 Use default copy constructor and assignment operator. More...
 
Componentoperator= (const Component &)=default
 
virtual ~Component ()=default
 Destructor is virtual to allow concrete Component to cleanup. More...
 
virtual void generateDecorations (bool fixed, const ModelDisplayHints &hints, const SimTK::State &state, SimTK::Array_< SimTK::DecorativeGeometry > &appendToThis) const
 Optional method for generating arbitrary display geometry that reflects this Component at the specified state. More...
 
const SimTK::MultibodySystem & getSystem () const
 Get the underlying MultibodySystem that this component is connected to. More...
 
bool hasSystem () const
 Check if this component has an underlying MultibodySystem. More...
 
bool isComponentInOwnershipTree (const Component *component) const
 Does the provided component already exist anywhere in the ownership tree (not just subcomponents of this component)? More...
 
void addComponent (Component *subcomponent)
 
Add a Component (as a subcomponent) of this component. More...
 
template<typename T = Component>
ComponentList< const T > getComponentList () const
 Get an iterator through the underlying subcomponents that this component is composed of. More...
 
template<typename T = Component>
ComponentList< T > updComponentList ()
 Similar to getComponentList(), except the resulting list allows one to modify the components. More...
 
template<typename T = Component>
unsigned countNumComponents () const
 Uses getComponentList<T>() to count the number of underlying subcomponents of the specified type. More...
 
std::string getAbsolutePathString () const
 Get the complete (absolute) pathname for this Component to its ancestral Component, which is the root of the tree to which this Component belongs. More...
 
ComponentPath getAbsolutePath () const
 Return a ComponentPath of the absolute path of this Component. More...
 
std::string getRelativePathString (const Component &wrt) const
 Get the relative path of this Component with respect to another Component, as a string. More...
 
ComponentPath getRelativePath (const Component &wrt) const
 Get the relative path of this Component with respect to another Component. More...
 
bool hasComponent (const std::string &pathname) const
 Query if there is a component (of any type) at the specified path name. More...
 
template<class C = Component>
bool hasComponent (const std::string &pathname) const
 Query if there is a component of a given type at the specified path name. More...
 
template<class C = Component>
const C & getComponent (const std::string &pathname) const
 Get a unique subcomponent of this Component by its path name and type 'C'. More...
 
template<class C = Component>
const C & getComponent (const ComponentPath &pathname) const
 
const ComponentgetComponent (const std::string &pathname) const
 Similar to the templatized getComponent(), except this returns the component as the generic Component type. More...
 
template<class C = Component>
C & updComponent (const std::string &name)
 Get a writable reference to a subcomponent. More...
 
template<class C = Component>
C & updComponent (const ComponentPath &name)
 
ComponentupdComponent (const std::string &pathname)
 Similar to the templatized updComponent(), except this returns the component as the generic Component type. More...
 
unsigned printComponentsMatching (const std::string &substring) const
 Print a list to the console of all components whose absolute path name contains the given string. More...
 
int getNumStateVariables () const
 Get the number of "continuous" state variables maintained by the Component and its subcomponents. More...
 
Array< std::string > getStateVariableNames () const
 Get the names of "continuous" state variables maintained by the Component and its subcomponents. More...
 
template<class C = Component>
const C * findComponent (const ComponentPath &pathToFind) const
 Find a Component to which this Component is an ancestor—in other words, a Component that is directly owned by this Component or is owned by one of its sub-components, sub-sub-components, etc. More...
 
template<class C = Component>
const C * findComponent (const std::string &pathToFind) const
 Same as findComponent(const ComponentPath&), but accepting a string (a path or just a name) as input. More...
 
const StateVariabletraverseToStateVariable (const std::string &pathName) const
 Get a StateVariable anywhere in the Component tree, given a StateVariable path. More...
 
void finalizeFromProperties ()
 Define a Component's internal data members and structure according to its properties. More...
 
void finalizeConnections (Component &root)
 Satisfy the Component's connections specified by its Sockets and Inputs. More...
 
void clearConnections ()
 Disconnect/clear this Component from its aggregate component. More...
 
void addToSystem (SimTK::MultibodySystem &system) const
 Have the Component add itself to the underlying computational System. More...
 
void initStateFromProperties (SimTK::State &state) const
 Initialize Component's state variable values from its properties. More...
 
void setPropertiesFromState (const SimTK::State &state)
 Set Component's properties given a state. More...
 
int getNumSockets () const
 Get the number of Sockets in this Component. More...
 
std::vector< std::string > getSocketNames ()
 Collect and return the names of the sockets in this component. More...
 
template<typename T >
const T & getConnectee (const std::string &name) const
 Get the "connectee" object that the Component's Socket is bound to. More...
 
const ObjectgetConnectee (const std::string &name) const
 Get the connectee as an Object. More...
 
const AbstractSocketgetSocket (const std::string &name) const
 Get an AbstractSocket for the given socket name. More...
 
AbstractSocketupdSocket (const std::string &name)
 Get a writable reference to the AbstractSocket for the given socket name. More...
 
template<typename T >
const Socket< T > & getSocket (const std::string &name) const
 Get a const reference to the concrete Socket provided by this Component by name. More...
 
template<typename T >
Socket< T > & updSocket (const std::string &name)
 Get a writable reference to the concrete Socket provided by this Component by name. More...
 
void printSubcomponentInfo () const
 List all subcomponents by name and recurse into these components to list their subcomponents, and so on. More...
 
void printSocketInfo () const
 List all the Sockets of this component and whether or not they are connected. More...
 
void printInputInfo () const
 List all the inputs of this component and whether or not they are connected. More...
 
template<typename C >
void printSubcomponentInfo () const
 
void printOutputInfo (const bool includeDescendants=true) const
 Print outputs of this component and optionally, those of all subcomponents. More...
 
int getNumInputs () const
 Access the number of Inputs that this component has. More...
 
int getNumOutputs () const
 Access the number of Outputs that this component has. More...
 
std::vector< std::string > getInputNames () const
 Collect and return the names of Inputs in this component as an std::vector. More...
 
std::vector< std::string > getOutputNames () const
 Collect and return the names of Outputs in this component as an std::vector. More...
 
const AbstractInputgetInput (const std::string &name) const
 Get an Input provided by this Component by name. More...
 
AbstractInputupdInput (const std::string &name)
 Get a writable reference to an Input provided by this Component by name. More...
 
template<typename T >
const Input< T > & getInput (const std::string &name) const
 Get a concrete Input that you can directly ask for its values. More...
 
const AbstractOutputgetOutput (const std::string &name) const
 Get the Output provided by this Component by name. More...
 
AbstractOutputupdOutput (const std::string &name)
 Get a writable reference to an Output provided by this Component by name. More...
 
SimTK::IteratorRange< OutputConstIteratorgetOutputs () const
 Iterate through all Outputs of this component. More...
 
int getModelingOption (const SimTK::State &state, const std::string &name) const
 Get a ModelingOption flag for this Component by name. More...
 
void setModelingOption (SimTK::State &state, const std::string &name, int flag) const
 Set the value of a ModelingOption flag for this Component. More...
 
template<typename T >
const T & getInputValue (const SimTK::State &state, const std::string &name) const
 Get the Input value that this component is dependent on. More...
 
template<typename T >
const T & getOutputValue (const SimTK::State &state, const std::string &name) const
 Get the Output value provided by this Component by name. More...
 
double getStateVariableValue (const SimTK::State &state, const std::string &name) const
 Get the value of a state variable allocated by this Component. More...
 
void setStateVariableValue (SimTK::State &state, const std::string &name, double value) const
 Set the value of a state variable allocated by this Component by name. More...
 
SimTK::Vector getStateVariableValues (const SimTK::State &state) const
 Get all values of the state variables allocated by this Component. More...
 
void setStateVariableValues (SimTK::State &state, const SimTK::Vector &values) const
 Set all values of the state variables allocated by this Component. More...
 
double getStateVariableDerivativeValue (const SimTK::State &state, const std::string &name) const
 Get the value of a state variable derivative computed by this Component. More...
 
double getDiscreteVariableValue (const SimTK::State &state, const std::string &name) const
 Get the value of a discrete variable allocated by this Component by name. More...
 
void setDiscreteVariableValue (SimTK::State &state, const std::string &name, double value) const
 Set the value of a discrete variable allocated by this Component by name. More...
 
template<class T >
SimTK::CacheEntryIndex getCacheVariableIndex (const CacheVariable< T > &cv) const
 Get the index of a Component's cache variable in the Subsystem for allocations. More...
 
SimTK::CacheEntryIndex getCacheVariableIndex (const std::string &name) const
 Get the index of a Component's cache variable in the Subsystem for allocations. More...
 
template<class T >
const T & getCacheVariableValue (const SimTK::State &state, const std::string &name) const
 Get the value of a cache variable allocated by this Component by name. More...
 
template<class T >
const T & getCacheVariableValue (const SimTK::State &state, const CacheVariable< T > &cv) const
 Get the value of a cache variable allocated by this Component. More...
 
template<typename T >
void setCacheVariableValue (const SimTK::State &state, const std::string &k, T value) const
 Set the value of a cache variable, identified by name, to a new value and mark the cache variable as valid. More...
 
template<typename T >
void setCacheVariableValue (const SimTK::State &state, const CacheVariable< T > &cv, T value) const
 Set the value of a cache variable to a new value and mark the cache variable as valid. More...
 
template<typename T >
T & updCacheVariableValue (const SimTK::State &state, const std::string &name) const
 Returns a mutable reference to the value of a cache variable identified by name. More...
 
template<typename T >
T & updCacheVariableValue (const SimTK::State &state, const CacheVariable< T > &cv) const
 Returns a mutable reference to the value of a cache variable. More...
 
bool isCacheVariableValid (const SimTK::State &state, const std::string &name) const
 Returns true if the cache variable, identified by name, is valid. More...
 
template<class T >
bool isCacheVariableValid (const SimTK::State &state, const CacheVariable< T > &cv) const
 Returns true if the cache variable is valid. More...
 
void markCacheVariableValid (const SimTK::State &state, const std::string &name) const
 Marks the value of a cache variable, identified by name, as valid. More...
 
template<typename T >
void markCacheVariableValid (const SimTK::State &state, const CacheVariable< T > &cv) const
 Marks the value of a cache variable as valid. More...
 
void markCacheVariableInvalid (const SimTK::State &state, const std::string &name) const
 Marks the value of a cache variable, identified by name, as invalid. More...
 
template<class T >
void markCacheVariableInvalid (const SimTK::State &state, const CacheVariable< T > &cv) const
 Marks the value of a cache variable as invalid. More...
 
const ComponentgetOwner () const
 Access the owner of this Component. More...
 
bool hasOwner () const
 (For advanced users) Check if this Component has an owner. More...
 
const ComponentgetRoot () const
 Obtain the root Component, which is this component if it is orphaned. More...
 
- Public Member Functions inherited from OpenSim::Object
virtual ~Object ()
 Virtual destructor for cleanup. More...
 
bool isEqualTo (const Object &aObject) const
 Equality operator wrapper for use from languages not supporting operator overloading. More...
 
Objectoperator= (const Object &aObject)
 Copy assignment copies he base class fields, including the properties. More...
 
virtual bool operator== (const Object &aObject) const
 Determine if two objects are equal. More...
 
virtual bool operator< (const Object &aObject) const
 Provide an ordering for objects so they can be put in sorted containers. More...
 
void setName (const std::string &name)
 Set the name of the Object. More...
 
const std::string & getName () const
 Get the name of this Object. More...
 
void setDescription (const std::string &description)
 Set description, a one-liner summary. More...
 
const std::string & getDescription () const
 Get description, a one-liner summary. More...
 
const std::string & getAuthors () const
 Get Authors of this Object. More...
 
void setAuthors (const std::string &authors)
 Set Authors of this object. More...
 
const std::string & getReferences () const
 Get references or publications to cite if using this object. More...
 
void setReferences (const std::string &references)
 Set references or publications to cite if using this object. More...
 
int getNumProperties () const
 Determine how many properties are stored with this Object. More...
 
const AbstractPropertygetPropertyByIndex (int propertyIndex) const
 Get a const reference to a property by its index number, returned as an AbstractProperty. More...
 
AbstractPropertyupdPropertyByIndex (int propertyIndex)
 Get a writable reference to a property by its index number, returned as an AbstractProperty. More...
 
bool hasProperty (const std::string &name) const
 Return true if this Object has a property of any type with the given name, which must not be empty. More...
 
const AbstractPropertygetPropertyByName (const std::string &name) const
 Get a const reference to a property by its name, returned as an AbstractProperty. More...
 
AbstractPropertyupdPropertyByName (const std::string &name)
 Get a writable reference to a property by its name, returned as an AbstractProperty. More...
 
template<class T >
bool hasProperty () const
 Return true if this Object contains an unnamed, one-object property that contains objects of the given template type T. More...
 
template<class T >
const Property< T > & getProperty (const PropertyIndex &index) const
 Get property of known type Property<T> as a const reference; the property must be present and have the right type. More...
 
template<class T >
Property< T > & updProperty (const PropertyIndex &index)
 Get property of known type Property<T> as a writable reference; the property must be present and have the right type. More...
 
bool isObjectUpToDateWithProperties () const
 Returns true if no property's value has changed since the last time setObjectIsUpToDateWithProperties() was called. More...
 
void readObjectFromXMLNodeOrFile (SimTK::Xml::Element &objectElement, int versionNumber)
 We're given an XML element from which we are to populate this Object. More...
 
void updateXMLNode (SimTK::Xml::Element &parent, const AbstractProperty *prop=nullptr) const
 Serialize this object into the XML node that represents it. More...
 
bool getInlined () const
 Inlined means an in-memory Object that is not associated with an XMLDocument. More...
 
void setInlined (bool aInlined, const std::string &aFileName="")
 Mark this as inlined or not and optionally provide a file name to associate with the new XMLDocument for the non-inline case. More...
 
std::string getDocumentFileName () const
 If there is a document associated with this object then return the file name maintained by the document. More...
 
int getDocumentFileVersion () const
 If there is a document associated with this object then return its version number. More...
 
void setAllPropertiesUseDefault (bool aUseDefault)
 
bool print (const std::string &fileName) const
 Write this Object into an XML file of the given name; conventionally the suffix to use is ".osim". More...
 
std::string dump () const
 dump the XML representation of this Object into an std::string and return it. More...
 
virtual bool isA (const char *type) const
 The default implementation returns true only if the supplied string is "Object"; each Object-derived class overrides this to match its own class name. More...
 
const std::string & toString () const
 Wrapper to be used on Java side to display objects in tree; this returns just the object's name. More...
 
PropertySetgetPropertySet ()
 OBSOLETE: Get a reference to the PropertySet maintained by the Object. More...
 
const PropertySetgetPropertySet () const
 

Auto-generated functions

static Millard2012AccelerationMusclesafeDownCast (OpenSim::Object *obj)
 For use in MATLAB and Python to access the concrete class. More...
 
static const std::string & getClassName ()
 This returns "Millard2012AccelerationMuscle". More...
 
Millard2012AccelerationMuscleclone () const override
 Create a new heap-allocated copy of the concrete object to which this Object refers. More...
 
const std::string & getConcreteClassName () const override
 Returns the class name of the concrete Object-derived class of the actual object referenced by this Object, as a string. More...
 

Additional Inherited Members

- Static Public Member Functions inherited from OpenSim::Muscle
static MusclesafeDownCast (OpenSim::Object *obj)
 For use in MATLAB and Python to access the concrete class. More...
 
static const std::string & getClassName ()
 This returns "Muscle". More...
 
- Static Public Member Functions inherited from OpenSim::PathActuator
static PathActuatorsafeDownCast (OpenSim::Object *obj)
 For use in MATLAB and Python to access the concrete class. More...
 
static const std::string & getClassName ()
 This returns "PathActuator". More...
 
- Static Public Member Functions inherited from OpenSim::ScalarActuator
static ScalarActuatorsafeDownCast (OpenSim::Object *obj)
 For use in MATLAB and Python to access the concrete class. More...
 
static const std::string & getClassName ()
 This returns "ScalarActuator". More...
 
- Static Public Member Functions inherited from OpenSim::Actuator
static ActuatorsafeDownCast (OpenSim::Object *obj)
 For use in MATLAB and Python to access the concrete class. More...
 
static const std::string & getClassName ()
 This returns "Actuator". More...
 
- Static Public Member Functions inherited from OpenSim::Force
static ForcesafeDownCast (OpenSim::Object *obj)
 For use in MATLAB and Python to access the concrete class. More...
 
static const std::string & getClassName ()
 This returns "Force". More...
 
- Static Public Member Functions inherited from OpenSim::ModelComponent
static ModelComponentsafeDownCast (OpenSim::Object *obj)
 For use in MATLAB and Python to access the concrete class. More...
 
static const std::string & getClassName ()
 This returns "ModelComponent". More...
 
- Static Public Member Functions inherited from OpenSim::Component
static ComponentsafeDownCast (OpenSim::Object *obj)
 For use in MATLAB and Python to access the concrete class. More...
 
static const std::string & getClassName ()
 This returns "Component". More...
 
- Static Public Member Functions inherited from OpenSim::Object
static void registerType (const Object &defaultObject)
 Register an instance of a class; if the class is already registered it will be replaced. More...
 
static void renameType (const std::string &oldTypeName, const std::string &newTypeName)
 Support versioning by associating the current Object type with an old name. More...
 
static const ObjectgetDefaultInstanceOfType (const std::string &concreteClassName)
 Return a pointer to the default instance of the registered (concrete) Object whose class name is given, or NULL if the type is not registered. More...
 
template<class T >
static bool isObjectTypeDerivedFrom (const std::string &concreteClassName)
 Return true if the given concrete object type represents a subclass of the template object type T, and thus could be referenced with a T*. More...
 
static ObjectnewInstanceOfType (const std::string &concreteClassName)
 Create a new instance of the concrete Object type whose class name is given as concreteClassName. More...
 
static void getRegisteredTypenames (Array< std::string > &typeNames)
 Retrieve all the typenames registered so far. More...
 
template<class T >
static void getRegisteredObjectsOfGivenType (ArrayPtrs< T > &rArray)
 Return an array of pointers to the default instances of all registered (concrete) Object types that derive from a given Object-derived type that does not have to be concrete. More...
 
static bool PrintPropertyInfo (std::ostream &os, const std::string &classNameDotPropertyName, bool printFlagInfo=true)
 Dump formatted property information to a given output stream, useful for creating a "help" facility for registered objects. More...
 
static bool PrintPropertyInfo (std::ostream &os, const std::string &className, const std::string &propertyName, bool printFlagInfo=true)
 Same as the other signature but the class name and property name are provided as two separate strings. More...
 
static ObjectmakeObjectFromFile (const std::string &fileName)
 Create an OpenSim object whose type is based on the tag at the root node of the XML file passed in. More...
 
static const std::string & getClassName ()
 Return the name of this class as a string; i.e., "Object". More...
 
static void setSerializeAllDefaults (bool shouldSerializeDefaults)
 Static function to control whether all registered objects and their properties are written to the defaults section of output files rather than only those values for which the default was explicitly overwritten when read in from an input file or set programmatically. More...
 
static bool getSerializeAllDefaults ()
 Report the value of the "serialize all defaults" flag. More...
 
static bool isKindOf (const char *type)
 Returns true if the passed-in string is "Object"; each Object-derived class defines a method of this name for its own class name. More...
 
static void setDebugLevel (int newLevel)
 Set the amount of logging output. More...
 
static int getDebugLevel ()
 Get the current setting of debug level. More...
 
static ObjectSafeCopy (const Object *aObject)
 Use the clone() method to duplicate the given object unless the pointer is null in which case null is returned. More...
 
static void RegisterType (const Object &defaultObject)
 OBSOLETE alternate name for registerType(). More...
 
static void RenameType (const std::string &oldName, const std::string &newName)
 OBSOLETE alternate name for renameType(). More...
 

Detailed Description


This class implements a 3 state (activation,fiber length and fiber velocity) acceleration musculo-tendon model that has several advantages over equilibrium musculo-tendon models: it is possible to simulate 0 activation, it requires fewer integrator steps to simulate, and physiological active force-length (with a minimum value of 0) and force velocity (with true asymptotes at the maximum shortening and lengthening velocities) curves can be employed.

fig_Millard2012AccelerationMuscle.png

The dynamic equation of the mass, constrained to move in direction \( \hat{i} \) is given by the scalar equation:

\[ m \ddot{x} = F_{SE} - F_{CE} \cdot \hat{i} \]

The kinematic expression for the acceleration of the mass, \( \ddot{s} \), expressed in terms of the fiber length, \(l_{CE}\), and pennation angle \(\phi\) is

\[ \ddot{x} = \Big(\ddot{l}_{CE} \cos \phi - 2 \dot{l}_{CE}\dot{\phi}\sin\phi - \dot{\phi}^2 l_{CE} \cos \phi - \ddot{\phi} l_{CE} \sin \phi\Big) \]

The kinematic expression for the angular acceleration of the pennation angle can be found by taking the second derivative of the pennation constraint equation

\[ l_{CE} \sin \phi = h \]

which yields

\[ \ddot{\phi} = -\Big( \ddot{l}_{CE}\sin\phi + 2 \dot{l}_{CE} \dot{\phi} \cos\phi - \dot{\phi}^2 l_{CE} \sin \phi \Big) / \Big( l_{CE} \cos \phi \Big) \]

An expression for \( \ddot{l}_{CE}\) can be obtained by substituting in the equations \( \ddot{\phi} \) into the equation for \(\ddot{x}\) and simplifying:

\[ \ddot{l}_{CE} = \frac{1}{m} \Big( F_{SE} - F_{CE} \cdot \hat{i} \Big) \cos \phi + l_{CE} \dot{\phi}^2 \]

Notice that the above equation for \(\ddot{l}_{CE}\) has no singularities, provided that there are no singularities in \( F_{SE}\) and \( F_{M}\cdot\hat{i}\). The force the fiber applies to the tendon (in N), \(F_{CE}\cdot\hat{i}\), is given by (+'ve is tension)

\[ F_{CE} \cdot \hat{i} = f_{ISO}\Big(\mathbf{a} \mathbf{f}_L(\hat{l}_{CE}) \mathbf{f}_V(\frac{\hat{v}_{CE}}{v_{MAX}}) + \beta_{CE}\hat{v}_{CE} + \mathbf{f}_{PE}(\hat{l}_{CE})(1+\beta_{PE}\hat{v}_{CE}) - \mathbf{f}_K(\hat{l}_{CE})(1-\beta_{K}\hat{v}_{CE}) \Big) \cos \phi - f_{ISO} \Big( \mathbf{f}_{c\phi}(\cos \phi) (1- \beta_{c \phi} \frac{d}{dt}(\frac{l_{CE}\cos\phi}{l_{CE,OPT}\cos\phi_{OPT}})) \Big) \]

The force the tendon generates (in N) is given by (+'ve is tension)

\[ F_{SE} = f_{ISO} \mathbf{f}_{SE}(\hat{l}_{SE})(1+\beta_{SE}\hat{v}_{SE}) \]

Every elastic element ( \(\mathbf{f}_{PE}\), \(\mathbf{f}_{K}\), \(\mathbf{f}_{c\phi}\), and \(\mathbf{f}_{SE}\)) is accompanied by a non-linear damping element of a form that is identical to the damping found in a Hunt-Crossley contact model. Additionally a linear damping element, \(\beta_{CE}\hat{v}_{CE}\), is located in the fiber as in J.He et al. Damping is necessary to include in this model to prevent the mass from oscillating in a non-physiologic manner. Nonlinear damping Hunt-Crossley damping (where the damping force is scaled by the elastic force) has been chosen because this form of damping doesn't increase the stiffness of the system equations (because it is gradually turned on).

As with the Hunt-Crossley contact model, the force generated by the nonlinear spring and damper saturated so that it is greater than or equal to zero. This saturation is necessary to ensure that tension elements can only generate tensile forces, and that compressive elements only generate compressive forces. Note that the sign conventions have been chosen so that damping forces are generated in the correct direction for each element.

\begin{eqnarray*} (1+\beta_{PE}\hat{v}_{CE}) > 0 \\ (1-\beta_{K}\hat{v}_{CE}) > 0 \\ (1- \beta_{c \phi} \frac{d}{dt}(\frac{l_{CE}\cos\phi}{l_{CE,OPT}\cos\phi_{OPT}})) > 0 \\ (1+\beta_{SE}\hat{v}_{SE}) > 0 \end{eqnarray*}

For more information on these new terms please see the doxygen for FiberCompressiveForceLengthCurve, FiberCompressiveForceCosPennationCurve, and MuscleFirstOrderActivationDynamicModel.

Units

  • m: meters
  • rad: radians
  • N: Newtons
  • kg: kilograms
  • s: seconds

Caution

The Millard2012AccelerationMuscle class is experimental and has not been extensively tested in all operational conditions.

Usage

Note that this object should be updated through the set methods provided. These set methods will take care of rebuilding the muscle correctly. If you modify the properties directly, the curve will not be rebuilt, and upon calling a function that requires a state an exception will be thrown because the muscle is out of date with its properties.

Note that this muscle does not currently implement the ignore_tendon_compliance flag, nor the ignore_activation_dynamics flag.

Nomenclature

Note that dot notation is used to denote time derivatives (units of \(m/s\) and \(m/s^2\) in this case), where as the hat symbol (as in \(\hat{l}\), \(\hat{v}\)) is used to denote time derivatives that have been scaled by a characteristic dimension (appear in units of \(1/s\) and \(1/s^2\) in this case)

  • \(m\): is the mass located at the junction between the fiber and the tendon. This mass should be thought of as a time constant that indicates how quickly this model will converge to the force an equilibrium muscle-tendon model would produce ( \(kg\))
  • \(\ddot{x}\): is the acceleration of the mass, in the \(\hat{i}\) direction ( \(m/s^2\))
  • \(F_{SE}\): is the force developed by the tendon ( \(N\))
  • \(F_{CE}\cdot\hat{i}\): is the force developed by the fiber along the tendon ( \(N\))
  • \(l_{CE}\): Length of the fiber(m)
  • \(l_{CE,OPT}\): Length the fiber generates maximal isometric force (m)
  • \(\hat{l}_{CE}=l_{CE}/l_{CE,OPT}\): Normalized length of the fiber (dimensionless)
  • \(\hat{v}_{CE}=\dot{l}_{CE}/l_{CE,OPT}\): Fiber velocity divided by ( \(1/s\))
  • \(\hat{v}_{MAX}\): Maximum normalized fiber velocity ( \(l_{CE,OPT}/s\)). This quantity typically ranges between 10 and 15 lengths per second (1/s)
  • \(\phi\): Pennation angle(rad)
  • \(\phi_{OPT}\): Pennation angle when the fiber is at its optimal length (rad)
  • \(l_{SE}\): Length of the series element (tendon) (m)
  • \(l_{SE,R}\): Resting length of the series element(m)
  • \(\hat{l}_{SE} = l_{SE}/l_{SE,R}\): Normalized length of the series element (dimensionless)
  • \( \hat{v}_{SE} = \dot{l}_{SE}/l_{SE,R}\): Normalized velocity of the tendon (1/s)
  • \(f_{ISO}\): maximum force the muscle can develop statically ( \(\hat{v}_{CE}=0\)) at its optimal length ( \(l_{CE,OPT}\)) and pennation angle ( \(\phi_{OPT}\))
  • \(\mathbf{a}\): activation (unitless)
  • \(\mathbf{f}_L(\hat{l}_{CE})\): Active force length multiplier (dimensionless)
  • \(\mathbf{f}_V(\frac{\hat{v}_{CE}}{v_{MAX}})\): Force velocity multiplier (dimensionless)
  • \(\mathbf{f}_{PE}(\hat{l}_{CE})\): Passive force length multiplier (dimensionless)
  • \(\mathbf{f}_{K}(\hat{l}_{CE})\): Fiber compressive force length multiplier (dimensionless)
  • \(\mathbf{f}_{c\phi}(\cos \phi)\): Fiber compressive cosine pennation multiplier (dimensionless)
  • \(\mathbf{f}_{SE}(\hat{l}_{SE})\): Series element (tendon) force-length multiplier (dimensionless)
  • \(\beta_{CE}\): Fiber damping (s)
  • \(\beta_{PE}\): Fiber parallel element damping coefficient (s)
  • \(\beta_{K}\): Fiber compressive force length damping coefficient (s)
  • \(\beta_{c \phi}\): Fiber compressive cosine pennation damping coefficient (s)
  • \(\beta_{SE}\): Series element (tendon) force length damping coefficient (s)

References

Hunt,K., and Crossley,F. Coefficient of restitution interpreted as damping in vibroimpact. Transactions of the ASME Journal of Applied Mechanics, 42(E):440445, 1975.

J.He, W.S. Levine, and G.E. Leob."The Modelling of the Neuro-musculo-skeletal Control System of A Cat Hindlimb", Proceedings of the IEEE International Symposium on Intelligent Control, 1988.

Author
Matt Millard

Constructor & Destructor Documentation

◆ Millard2012AccelerationMuscle() [1/2]

OpenSim::Millard2012AccelerationMuscle::Millard2012AccelerationMuscle ( )

Default constructor: produces a non-functional empty muscle.

◆ Millard2012AccelerationMuscle() [2/2]

OpenSim::Millard2012AccelerationMuscle::Millard2012AccelerationMuscle ( const std::string &  aName,
double  aMaxIsometricForce,
double  aOptimalFiberLength,
double  aTendonSlackLength,
double  aPennationAngle 
)

Constructs a functional muscle using all of the default curves and activation model.

Parameters
aNameThe name of the muscle.
aMaxIsometricForceThe force generated by the muscle when it at its optimal resting length, has a contraction velocity of zero, and is fully activated (Newtons).
aOptimalFiberLengthThe optimal length of the muscle fiber (meters).
aTendonSlackLengthThe resting length of the tendon (meters).
aPennationAngleThe angle of the fiber relative to the tendon when the fiber is at its optimal resting length (radians).

Member Function Documentation

◆ calcActivationRate()

double OpenSim::Millard2012AccelerationMuscle::calcActivationRate ( const SimTK::State &  s) const
protected


Parameters
sthe state of the model
Returns
the time derivative of activation

◆ calcFiberVelocityInfo()

void OpenSim::Millard2012AccelerationMuscle::calcFiberVelocityInfo ( const SimTK::State &  s,
FiberVelocityInfo fvi 
) const
finaloverrideprotectedvirtual

calculate muscle's velocity related values such fiber and tendon velocities,normalized velocities, pennation angular velocity, etc...

Parameters
sthe state of the model
fvithe fiber velocity info struct that will hold updated information about the muscle that is available at the velocity stage

Reimplemented from OpenSim::Muscle.

◆ calcMuscleDynamicsInfo()

void OpenSim::Millard2012AccelerationMuscle::calcMuscleDynamicsInfo ( const SimTK::State &  s,
MuscleDynamicsInfo mdi 
) const
finaloverrideprotectedvirtual

calculate muscle's active and passive force-length, force-velocity, tendon force, relationships and their related values

Parameters
sthe state of the model
mdithe muscle dynamics info struct that will hold updated information about the muscle that is available at the dynamics stage

Reimplemented from OpenSim::Muscle.

◆ calcMuscleLengthInfo()

void OpenSim::Millard2012AccelerationMuscle::calcMuscleLengthInfo ( const SimTK::State &  s,
MuscleLengthInfo mli 
) const
finaloverrideprotectedvirtual

calculate muscle's position related values such fiber and tendon lengths, normalized lengths, pennation angle, etc...

Parameters
sthe state of the model
mlithe muscle length info struct that will hold updated information about the muscle that is available at the position stage

Reimplemented from OpenSim::Muscle.

◆ calcMusclePotentialEnergyInfo()

void OpenSim::Millard2012AccelerationMuscle::calcMusclePotentialEnergyInfo ( const SimTK::State &  s,
MusclePotentialEnergyInfo mpei 
) const
finaloverrideprotectedvirtual

calculate muscle's fiber and tendon potential energy

Reimplemented from OpenSim::Muscle.

◆ clone()

Millard2012AccelerationMuscle* OpenSim::Millard2012AccelerationMuscle::clone ( ) const
inlineoverridevirtual

Create a new heap-allocated copy of the concrete object to which this Object refers.

It is up to the caller to delete the returned object when no longer needed. Every concrete object deriving from Object implements this pure virtual method automatically, via the declaration macro it invokes (e.g., OpenSim_DECLARE_CONCRETE_OBJECT()). Note that the concrete class overrides modify the return type to be a pointer to the concrete object; that still overrides the base class method because the return type is covariant with (that is, derives from) Object.

Implements OpenSim::Muscle.

◆ computeActuation()

double OpenSim::Millard2012AccelerationMuscle::computeActuation ( const SimTK::State &  s) const
finaloverridevirtual


Parameters
sthe state of the system
Returns
the tensile force the muscle is generating in N

Implements OpenSim::Muscle.

◆ computeInitialFiberEquilibrium()

void OpenSim::Millard2012AccelerationMuscle::computeInitialFiberEquilibrium ( SimTK::State &  s) const
finaloverridevirtual

This function computes the fiber length such that muscle fiber and tendon are developing the same force, and so that the velocity of the entire muscle-tendon is spread between the fiber and the tendon according to their relative compliances.

Parameters
sthe state of the system
Exceptions
MuscleCannotEquilibrate

Implements OpenSim::Muscle.

◆ computeStateVariableDerivatives()

void OpenSim::Millard2012AccelerationMuscle::computeStateVariableDerivatives ( const SimTK::State &  s) const
finaloverrideprotectedvirtual

computes state variable derivatives

Parameters
sthe state of the model

Reimplemented from OpenSim::Component.

◆ extendAddToSystem()

void OpenSim::Millard2012AccelerationMuscle::extendAddToSystem ( SimTK::MultibodySystem &  system) const
finaloverrideprotectedvirtual

Creates the ModelComponent so that it can be used in simulation.

Parameters
systemthe multibody system

Reimplemented from OpenSim::Component.

◆ extendInitStateFromProperties()

void OpenSim::Millard2012AccelerationMuscle::extendInitStateFromProperties ( SimTK::State &  s) const
finaloverrideprotectedvirtual

Initializes the state of the ModelComponent.

Parameters
sthe state of the model

Reimplemented from OpenSim::Component.

◆ extendPostScale()

void OpenSim::Millard2012AccelerationMuscle::extendPostScale ( const SimTK::State &  s,
const ScaleSet scaleSet 
)
overridevirtual

Adjust the properties of the muscle after the model has been scaled.

The optimal fiber length and tendon slack length are each multiplied by the ratio of the current path length and the path length before scaling.

Reimplemented from OpenSim::ModelComponent.

◆ extendSetPropertiesFromState()

void OpenSim::Millard2012AccelerationMuscle::extendSetPropertiesFromState ( const SimTK::State &  s)
finaloverrideprotectedvirtual

Sets the default state for ModelComponent.

Parameters
sthe state of the model

Reimplemented from OpenSim::Component.

◆ get_ActiveForceLengthCurve()

const ActiveForceLengthCurve& OpenSim::Millard2012AccelerationMuscle::get_ActiveForceLengthCurve ( ) const
inline

Get the value of the ActiveForceLengthCurve property.

◆ get_default_activation()

const double& OpenSim::Millard2012AccelerationMuscle::get_default_activation ( ) const
inline

Get the value of the default_activation property.

◆ get_default_fiber_length()

const double& OpenSim::Millard2012AccelerationMuscle::get_default_fiber_length ( ) const
inline

Get the value of the default_fiber_length property.

◆ get_default_fiber_velocity()

const double& OpenSim::Millard2012AccelerationMuscle::get_default_fiber_velocity ( ) const
inline

Get the value of the default_fiber_velocity property.

◆ get_fiber_compressive_force_cos_pennation_damping()

const double& OpenSim::Millard2012AccelerationMuscle::get_fiber_compressive_force_cos_pennation_damping ( ) const
inline

Get the value of the fiber_compressive_force_cos_pennation_damping property.

◆ get_fiber_compressive_force_length_damping()

const double& OpenSim::Millard2012AccelerationMuscle::get_fiber_compressive_force_length_damping ( ) const
inline

Get the value of the fiber_compressive_force_length_damping property.

◆ get_fiber_damping()

const double& OpenSim::Millard2012AccelerationMuscle::get_fiber_damping ( ) const
inline

Get the value of the fiber_damping property.

◆ get_fiber_force_length_damping()

const double& OpenSim::Millard2012AccelerationMuscle::get_fiber_force_length_damping ( ) const
inline

Get the value of the fiber_force_length_damping property.

◆ get_FiberCompressiveForceCosPennationCurve()

const FiberCompressiveForceCosPennationCurve& OpenSim::Millard2012AccelerationMuscle::get_FiberCompressiveForceCosPennationCurve ( ) const
inline

Get the value of the FiberCompressiveForceCosPennationCurve property.

◆ get_FiberCompressiveForceLengthCurve()

const FiberCompressiveForceLengthCurve& OpenSim::Millard2012AccelerationMuscle::get_FiberCompressiveForceLengthCurve ( ) const
inline

Get the value of the FiberCompressiveForceLengthCurve property.

◆ get_FiberForceLengthCurve()

const FiberForceLengthCurve& OpenSim::Millard2012AccelerationMuscle::get_FiberForceLengthCurve ( ) const
inline

Get the value of the FiberForceLengthCurve property.

◆ get_ForceVelocityCurve()

const ForceVelocityCurve& OpenSim::Millard2012AccelerationMuscle::get_ForceVelocityCurve ( ) const
inline

Get the value of the ForceVelocityCurve property.

◆ get_mass()

const double& OpenSim::Millard2012AccelerationMuscle::get_mass ( ) const
inline

Get the value of the mass property.

◆ get_MuscleFirstOrderActivationDynamicModel()

const MuscleFirstOrderActivationDynamicModel& OpenSim::Millard2012AccelerationMuscle::get_MuscleFirstOrderActivationDynamicModel ( ) const
inline

Get the value of the MuscleFirstOrderActivationDynamicModel property.

◆ get_tendon_force_length_damping()

const double& OpenSim::Millard2012AccelerationMuscle::get_tendon_force_length_damping ( ) const
inline

Get the value of the tendon_force_length_damping property.

◆ get_TendonForceLengthCurve()

const TendonForceLengthCurve& OpenSim::Millard2012AccelerationMuscle::get_TendonForceLengthCurve ( ) const
inline

Get the value of the TendonForceLengthCurve property.

◆ getActivationModel()

const MuscleFirstOrderActivationDynamicModel& OpenSim::Millard2012AccelerationMuscle::getActivationModel ( ) const


Returns
the MuscleFirstOrderActivationDynamicModel that this muscle model uses

◆ getActivationRate()

double OpenSim::Millard2012AccelerationMuscle::getActivationRate ( const SimTK::State &  s) const


Parameters
sThe state of the system
Returns
the time derivative of activation

◆ getActiveForceLengthCurve()

const ActiveForceLengthCurve& OpenSim::Millard2012AccelerationMuscle::getActiveForceLengthCurve ( ) const


Returns
the ActiveForceLengthCurve that this muscle model uses

◆ getClassName()

static const std::string& OpenSim::Millard2012AccelerationMuscle::getClassName ( )
inlinestatic

This returns "Millard2012AccelerationMuscle".

See getConcreteClassName() if you want the class name of the underlying concrete object instead.

◆ getConcreteClassName()

const std::string& OpenSim::Millard2012AccelerationMuscle::getConcreteClassName ( ) const
inlineoverridevirtual

Returns the class name of the concrete Object-derived class of the actual object referenced by this Object, as a string.

This is the string that is used as the tag for this concrete object in an XML file. Every concrete class derived from Object automatically overrides this method via the declaration macro it uses. See getClassName() to get the class name of the referencing (possibly abstract) class rather than the concrete object.

See also
getClassName()

Implements OpenSim::Muscle.

◆ getDefaultActivation()

double OpenSim::Millard2012AccelerationMuscle::getDefaultActivation ( ) const


Returns
the default activation level that is used as an initial condition if none is provided by the user.

◆ getDefaultFiberLength()

double OpenSim::Millard2012AccelerationMuscle::getDefaultFiberLength ( ) const


Returns
the default fiber length that is used as an initial condition if none is provided by the user.

◆ getDefaultFiberVelocity()

double OpenSim::Millard2012AccelerationMuscle::getDefaultFiberVelocity ( ) const


Returns
the default fiber velocity that is used as an initial condition if none is provided by the user.

◆ getFiberAcceleration()

double OpenSim::Millard2012AccelerationMuscle::getFiberAcceleration ( const SimTK::State &  s) const


Parameters
sThe state of the system
Returns
the acceleration of the fiber (m/s)

◆ getFiberCompressiveForceCosPennationCurve()

const FiberCompressiveForceCosPennationCurve& OpenSim::Millard2012AccelerationMuscle::getFiberCompressiveForceCosPennationCurve ( ) const


Returns
the FiberCompressiveForceCosPennationCurve that this muscle model uses.

◆ getFiberCompressiveForceCosPennationMultiplier()

double OpenSim::Millard2012AccelerationMuscle::getFiberCompressiveForceCosPennationMultiplier ( SimTK::State &  s) const


Parameters
sthe state of the system
Returns
the normalized force term associated with the compressive force cosine pennation element, \(\mathbf{f}_{c\phi}(\cos \phi)\), in the equilibrium equation

◆ getFiberCompressiveForceLengthCurve()

const FiberCompressiveForceLengthCurve& OpenSim::Millard2012AccelerationMuscle::getFiberCompressiveForceLengthCurve ( ) const


Returns
the FiberCompressiveForceLengthCurve that this muscle model uses

◆ getFiberCompressiveForceLengthMultiplier()

double OpenSim::Millard2012AccelerationMuscle::getFiberCompressiveForceLengthMultiplier ( SimTK::State &  s) const


Parameters
sthe state of the system
Returns
the normalized force term associated with the compressive force length element, \(\mathbf{f}_K(\hat{l}_{CE})\), in the equilibrium equation

◆ getFiberForceLengthCurve()

const FiberForceLengthCurve& OpenSim::Millard2012AccelerationMuscle::getFiberForceLengthCurve ( ) const


Returns
the FiberForceLengthCurve that this muscle model uses

◆ getFiberStiffnessAlongTendon()

double OpenSim::Millard2012AccelerationMuscle::getFiberStiffnessAlongTendon ( const SimTK::State &  s) const


Returns
the stiffness of the muscle fibers along the tendon (N/m)

◆ getFiberVelocity()

double OpenSim::Millard2012AccelerationMuscle::getFiberVelocity ( const SimTK::State &  s) const


Parameters
sThe state of the system
Returns
the velocity of the fiber (m/s)

◆ getForceVelocityCurve()

const ForceVelocityCurve& OpenSim::Millard2012AccelerationMuscle::getForceVelocityCurve ( ) const


Returns
the ForceVelocityInverseCurve that this muscle model uses

◆ getMass()

double OpenSim::Millard2012AccelerationMuscle::getMass ( ) const


Returns
the size of the mass between the tendon and fiber

◆ getPennationModel()

const MuscleFixedWidthPennationModel& OpenSim::Millard2012AccelerationMuscle::getPennationModel ( ) const


Returns
the MuscleFixedWidthPennationModel that this muscle model uses

◆ getStateVariableDeriv()

double OpenSim::Millard2012AccelerationMuscle::getStateVariableDeriv ( const SimTK::State &  s,
const std::string &  aStateName 
) const
protected


Get the derivative of an actuator state, by index.

Parameters
sthe state
aStateNamethe name of the state to get.
Returns
The value of the state derivative

◆ getTendonForceLengthCurve()

const TendonForceLengthCurve& OpenSim::Millard2012AccelerationMuscle::getTendonForceLengthCurve ( ) const


Returns
the TendonForceLengthCurve that this muscle model uses

◆ getTendonForceMultiplier()

double OpenSim::Millard2012AccelerationMuscle::getTendonForceMultiplier ( SimTK::State &  s) const


Parameters
sthe state of the system
Returns
the normalized force term associated with tendon element, \(\mathbf{f}_{SE}(\hat{l}_{T})\), in the equilibrium equation

◆ safeDownCast()

static Millard2012AccelerationMuscle* OpenSim::Millard2012AccelerationMuscle::safeDownCast ( OpenSim::Object obj)
inlinestatic

For use in MATLAB and Python to access the concrete class.

Example: cObj = Millard2012AccelerationMuscle.safeDownCast(obj). This is equivalent to dynamic_cast<Millard2012AccelerationMuscle*>(obj) in C++.

◆ set_ActiveForceLengthCurve()

void OpenSim::Millard2012AccelerationMuscle::set_ActiveForceLengthCurve ( const ActiveForceLengthCurve value)
inline

Set the value of the ActiveForceLengthCurve property.

◆ set_default_activation()

void OpenSim::Millard2012AccelerationMuscle::set_default_activation ( const double &  value)
inline

Set the value of the default_activation property.

◆ set_default_fiber_length()

void OpenSim::Millard2012AccelerationMuscle::set_default_fiber_length ( const double &  value)
inline

Set the value of the default_fiber_length property.

◆ set_default_fiber_velocity()

void OpenSim::Millard2012AccelerationMuscle::set_default_fiber_velocity ( const double &  value)
inline

Set the value of the default_fiber_velocity property.

◆ set_fiber_compressive_force_cos_pennation_damping()

void OpenSim::Millard2012AccelerationMuscle::set_fiber_compressive_force_cos_pennation_damping ( const double &  value)
inline

Set the value of the fiber_compressive_force_cos_pennation_damping property.

◆ set_fiber_compressive_force_length_damping()

void OpenSim::Millard2012AccelerationMuscle::set_fiber_compressive_force_length_damping ( const double &  value)
inline

Set the value of the fiber_compressive_force_length_damping property.

◆ set_fiber_damping()

void OpenSim::Millard2012AccelerationMuscle::set_fiber_damping ( const double &  value)
inline

Set the value of the fiber_damping property.

◆ set_fiber_force_length_damping()

void OpenSim::Millard2012AccelerationMuscle::set_fiber_force_length_damping ( const double &  value)
inline

Set the value of the fiber_force_length_damping property.

◆ set_FiberCompressiveForceCosPennationCurve()

void OpenSim::Millard2012AccelerationMuscle::set_FiberCompressiveForceCosPennationCurve ( const FiberCompressiveForceCosPennationCurve value)
inline

Set the value of the FiberCompressiveForceCosPennationCurve property.

◆ set_FiberCompressiveForceLengthCurve()

void OpenSim::Millard2012AccelerationMuscle::set_FiberCompressiveForceLengthCurve ( const FiberCompressiveForceLengthCurve value)
inline

Set the value of the FiberCompressiveForceLengthCurve property.

◆ set_FiberForceLengthCurve()

void OpenSim::Millard2012AccelerationMuscle::set_FiberForceLengthCurve ( const FiberForceLengthCurve value)
inline

Set the value of the FiberForceLengthCurve property.

◆ set_ForceVelocityCurve()

void OpenSim::Millard2012AccelerationMuscle::set_ForceVelocityCurve ( const ForceVelocityCurve value)
inline

Set the value of the ForceVelocityCurve property.

◆ set_mass()

void OpenSim::Millard2012AccelerationMuscle::set_mass ( const double &  value)
inline

Set the value of the mass property.

◆ set_MuscleFirstOrderActivationDynamicModel()

void OpenSim::Millard2012AccelerationMuscle::set_MuscleFirstOrderActivationDynamicModel ( const MuscleFirstOrderActivationDynamicModel value)
inline

Set the value of the MuscleFirstOrderActivationDynamicModel property.

◆ set_tendon_force_length_damping()

void OpenSim::Millard2012AccelerationMuscle::set_tendon_force_length_damping ( const double &  value)
inline

Set the value of the tendon_force_length_damping property.

◆ set_TendonForceLengthCurve()

void OpenSim::Millard2012AccelerationMuscle::set_TendonForceLengthCurve ( const TendonForceLengthCurve value)
inline

Set the value of the TendonForceLengthCurve property.

◆ setActivation()

void OpenSim::Millard2012AccelerationMuscle::setActivation ( SimTK::State &  s,
double  activation 
) const
overridevirtual


Parameters
sthe state of the system
activationthe desired activation level

Implements OpenSim::Muscle.

◆ setActivationModel()

void OpenSim::Millard2012AccelerationMuscle::setActivationModel ( MuscleFirstOrderActivationDynamicModel aActivationMdl)


Parameters
aActivationMdlthe MuscleFirstOrderActivationDynamicModel that this muscle model uses to simulate activation dynamics

◆ setActiveForceLengthCurve()

void OpenSim::Millard2012AccelerationMuscle::setActiveForceLengthCurve ( ActiveForceLengthCurve aActiveForceLengthCurve)


Parameters
aActiveForceLengthCurvethe ActiveForceLengthCurve that this muscle model uses to scale active fiber force as a function of length

◆ setDefaultActivation()

void OpenSim::Millard2012AccelerationMuscle::setDefaultActivation ( double  activation)


Parameters
activationthe default activation level that is used to initialize the muscle

◆ setDefaultFiberLength()

void OpenSim::Millard2012AccelerationMuscle::setDefaultFiberLength ( double  fiberLength)


Parameters
fiberLengththe default fiber length that is used to initialize the muscle

◆ setDefaultFiberVelocity()

void OpenSim::Millard2012AccelerationMuscle::setDefaultFiberVelocity ( double  fiberVelocity)


Parameters
fiberVelocitythe default fiber velocity that is used to initialize the muscle

◆ setFiberCompressiveForceCosPennationCurve()

void OpenSim::Millard2012AccelerationMuscle::setFiberCompressiveForceCosPennationCurve ( FiberCompressiveForceCosPennationCurve aFiberCompressiveForceCosPennationCurve)


Parameters
aFiberCompressiveForceCosPennationCurvethe FiberCompressiveForceCosPennationCurve that this muscle model uses to prevent pennation angles from approaching 90 degrees, which is associated with a singularity in this model.

◆ setFiberCompressiveForceLengthCurve()

void OpenSim::Millard2012AccelerationMuscle::setFiberCompressiveForceLengthCurve ( FiberCompressiveForceLengthCurve aFiberCompressiveForceLengthCurve)


Parameters
aFiberCompressiveForceLengthCurvethe FiberCompressiveForceLengthCurve that this muscle model uses to ensure the length of the fiber is always greater than a physically realistic lower bound.

◆ setFiberForceLengthCurve()

void OpenSim::Millard2012AccelerationMuscle::setFiberForceLengthCurve ( FiberForceLengthCurve aFiberForceLengthCurve)


Parameters
aFiberForceLengthCurvethe FiberForceLengthCurve that this muscle model uses to calculate the passive force the muscle fiber generates as the length of the fiber changes

◆ setFiberLength()

void OpenSim::Millard2012AccelerationMuscle::setFiberLength ( SimTK::State &  s,
double  fiberLength 
) const


Parameters
sthe state of the system
fiberLengththe desired fiber length (m)

◆ setFiberVelocity()

void OpenSim::Millard2012AccelerationMuscle::setFiberVelocity ( SimTK::State &  s,
double  fiberVelocity 
) const


Parameters
sthe state of the system
fiberVelocitythe desired fiber velocity (m/s)

◆ setForceVelocityCurve()

void OpenSim::Millard2012AccelerationMuscle::setForceVelocityCurve ( ForceVelocityCurve aForceVelocityCurve)


Parameters
aForceVelocityCurvethe ForceVelocityCurve that this muscle model uses to calculate the derivative of fiber length.

◆ setMass()

void OpenSim::Millard2012AccelerationMuscle::setMass ( double  mass)


Parameters
massThe size of the mass parameter between the fiber and the tendon. Making this parameter small will make the muscle model more rapidly converge to the results an equilibrium model would produce.

Conditions

    mass >= 0.001

◆ setStateVariableDeriv()

void OpenSim::Millard2012AccelerationMuscle::setStateVariableDeriv ( const SimTK::State &  s,
const std::string &  aStateName,
double  aValue 
) const
protected


Set the derivative of an actuator state, specified by name

Parameters
sthe state
aStateNameThe name of the state to set.
aValueThe value to set the state to.

◆ setTendonForceLengthCurve()

void OpenSim::Millard2012AccelerationMuscle::setTendonForceLengthCurve ( TendonForceLengthCurve aTendonForceLengthCurve)


Parameters
aTendonForceLengthCurvethe TendonForceLengthCurve that this muscle model uses to define the tendon force length curve

◆ upd_ActiveForceLengthCurve()

ActiveForceLengthCurve& OpenSim::Millard2012AccelerationMuscle::upd_ActiveForceLengthCurve ( )
inline

Get a writable reference to the ActiveForceLengthCurve property.

◆ upd_default_activation()

double& OpenSim::Millard2012AccelerationMuscle::upd_default_activation ( )
inline

Get a writable reference to the default_activation property.

◆ upd_default_fiber_length()

double& OpenSim::Millard2012AccelerationMuscle::upd_default_fiber_length ( )
inline

Get a writable reference to the default_fiber_length property.

◆ upd_default_fiber_velocity()

double& OpenSim::Millard2012AccelerationMuscle::upd_default_fiber_velocity ( )
inline

Get a writable reference to the default_fiber_velocity property.

◆ upd_fiber_compressive_force_cos_pennation_damping()

double& OpenSim::Millard2012AccelerationMuscle::upd_fiber_compressive_force_cos_pennation_damping ( )
inline

Get a writable reference to the fiber_compressive_force_cos_pennation_damping property.

◆ upd_fiber_compressive_force_length_damping()

double& OpenSim::Millard2012AccelerationMuscle::upd_fiber_compressive_force_length_damping ( )
inline

Get a writable reference to the fiber_compressive_force_length_damping property.

◆ upd_fiber_damping()

double& OpenSim::Millard2012AccelerationMuscle::upd_fiber_damping ( )
inline

Get a writable reference to the fiber_damping property.

◆ upd_fiber_force_length_damping()

double& OpenSim::Millard2012AccelerationMuscle::upd_fiber_force_length_damping ( )
inline

Get a writable reference to the fiber_force_length_damping property.

◆ upd_FiberCompressiveForceCosPennationCurve()

FiberCompressiveForceCosPennationCurve& OpenSim::Millard2012AccelerationMuscle::upd_FiberCompressiveForceCosPennationCurve ( )
inline

Get a writable reference to the FiberCompressiveForceCosPennationCurve property.

◆ upd_FiberCompressiveForceLengthCurve()

FiberCompressiveForceLengthCurve& OpenSim::Millard2012AccelerationMuscle::upd_FiberCompressiveForceLengthCurve ( )
inline

Get a writable reference to the FiberCompressiveForceLengthCurve property.

◆ upd_FiberForceLengthCurve()

FiberForceLengthCurve& OpenSim::Millard2012AccelerationMuscle::upd_FiberForceLengthCurve ( )
inline

Get a writable reference to the FiberForceLengthCurve property.

◆ upd_ForceVelocityCurve()

ForceVelocityCurve& OpenSim::Millard2012AccelerationMuscle::upd_ForceVelocityCurve ( )
inline

Get a writable reference to the ForceVelocityCurve property.

◆ upd_mass()

double& OpenSim::Millard2012AccelerationMuscle::upd_mass ( )
inline

Get a writable reference to the mass property.

◆ upd_MuscleFirstOrderActivationDynamicModel()

MuscleFirstOrderActivationDynamicModel& OpenSim::Millard2012AccelerationMuscle::upd_MuscleFirstOrderActivationDynamicModel ( )
inline

Get a writable reference to the MuscleFirstOrderActivationDynamicModel property.

◆ upd_tendon_force_length_damping()

double& OpenSim::Millard2012AccelerationMuscle::upd_tendon_force_length_damping ( )
inline

Get a writable reference to the tendon_force_length_damping property.

◆ upd_TendonForceLengthCurve()

TendonForceLengthCurve& OpenSim::Millard2012AccelerationMuscle::upd_TendonForceLengthCurve ( )
inline

Get a writable reference to the TendonForceLengthCurve property.

OpenSim Property, Socket, Output, Input Documentation

◆ ActiveForceLengthCurve

ActiveForceLengthCurve OpenSim::Millard2012AccelerationMuscle::ActiveForceLengthCurve

"active force length curve"

This property appears in XML files under the tag <ActiveForceLengthCurve>. This property was generated with the OpenSim_DECLARE_UNNAMED_PROPERTY macro; see Property to learn about the property system.

See also
get_ActiveForceLengthCurve(), upd_ActiveForceLengthCurve(), set_ActiveForceLengthCurve()

◆ default_activation

double OpenSim::Millard2012AccelerationMuscle::default_activation

"assumed initial activation level if none is assigned."

This property appears in XML files under the tag <default_activation>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.

See also
get_default_activation(), upd_default_activation(), set_default_activation()

◆ default_fiber_length

double OpenSim::Millard2012AccelerationMuscle::default_fiber_length

"assumed initial fiber length if none is assigned."

This property appears in XML files under the tag <default_fiber_length>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.

See also
get_default_fiber_length(), upd_default_fiber_length(), set_default_fiber_length()

◆ default_fiber_velocity

double OpenSim::Millard2012AccelerationMuscle::default_fiber_velocity

"assumed initial fiber velocity if none is assigned."

This property appears in XML files under the tag <default_fiber_velocity>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.

See also
get_default_fiber_velocity(), upd_default_fiber_velocity(), set_default_fiber_velocity()

◆ fiber_compressive_force_cos_pennation_damping

double OpenSim::Millard2012AccelerationMuscle::fiber_compressive_force_cos_pennation_damping

"fiber compressive force cos(pennationAngle) damping coefficient"

This property appears in XML files under the tag <fiber_compressive_force_cos_pennation_damping>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.

See also
get_fiber_compressive_force_cos_pennation_damping(), upd_fiber_compressive_force_cos_pennation_damping(), set_fiber_compressive_force_cos_pennation_damping()

◆ fiber_compressive_force_length_damping

double OpenSim::Millard2012AccelerationMuscle::fiber_compressive_force_length_damping

"fiber compressive force length damping coefficient"

This property appears in XML files under the tag <fiber_compressive_force_length_damping>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.

See also
get_fiber_compressive_force_length_damping(), upd_fiber_compressive_force_length_damping(), set_fiber_compressive_force_length_damping()

◆ fiber_damping

double OpenSim::Millard2012AccelerationMuscle::fiber_damping

"fiber damping coefficient"

This property appears in XML files under the tag <fiber_damping>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.

See also
get_fiber_damping(), upd_fiber_damping(), set_fiber_damping()

◆ fiber_force_length_damping

double OpenSim::Millard2012AccelerationMuscle::fiber_force_length_damping

"fiber force length damping coefficient"

This property appears in XML files under the tag <fiber_force_length_damping>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.

See also
get_fiber_force_length_damping(), upd_fiber_force_length_damping(), set_fiber_force_length_damping()

◆ FiberCompressiveForceCosPennationCurve

FiberCompressiveForceCosPennationCurve OpenSim::Millard2012AccelerationMuscle::FiberCompressiveForceCosPennationCurve

"fiber compressive force cos(pennationAngle) curve"

This property appears in XML files under the tag <FiberCompressiveForceCosPennationCurve>. This property was generated with the OpenSim_DECLARE_UNNAMED_PROPERTY macro; see Property to learn about the property system.

See also
get_FiberCompressiveForceCosPennationCurve(), upd_FiberCompressiveForceCosPennationCurve(), set_FiberCompressiveForceCosPennationCurve()

◆ FiberCompressiveForceLengthCurve

FiberCompressiveForceLengthCurve OpenSim::Millard2012AccelerationMuscle::FiberCompressiveForceLengthCurve

"fiber compressive force length curve"

This property appears in XML files under the tag <FiberCompressiveForceLengthCurve>. This property was generated with the OpenSim_DECLARE_UNNAMED_PROPERTY macro; see Property to learn about the property system.

See also
get_FiberCompressiveForceLengthCurve(), upd_FiberCompressiveForceLengthCurve(), set_FiberCompressiveForceLengthCurve()

◆ FiberForceLengthCurve

FiberForceLengthCurve OpenSim::Millard2012AccelerationMuscle::FiberForceLengthCurve

"fiber force length curve"

This property appears in XML files under the tag <FiberForceLengthCurve>. This property was generated with the OpenSim_DECLARE_UNNAMED_PROPERTY macro; see Property to learn about the property system.

See also
get_FiberForceLengthCurve(), upd_FiberForceLengthCurve(), set_FiberForceLengthCurve()

◆ ForceVelocityCurve

ForceVelocityCurve OpenSim::Millard2012AccelerationMuscle::ForceVelocityCurve

"force velocity curve"

This property appears in XML files under the tag <ForceVelocityCurve>. This property was generated with the OpenSim_DECLARE_UNNAMED_PROPERTY macro; see Property to learn about the property system.

See also
get_ForceVelocityCurve(), upd_ForceVelocityCurve(), set_ForceVelocityCurve()

◆ mass

double OpenSim::Millard2012AccelerationMuscle::mass

"lumped mass"

This property appears in XML files under the tag <mass>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.

See also
get_mass(), upd_mass(), set_mass()

◆ MuscleFirstOrderActivationDynamicModel

MuscleFirstOrderActivationDynamicModel OpenSim::Millard2012AccelerationMuscle::MuscleFirstOrderActivationDynamicModel

"activation dynamics model with a lower bound"

This property appears in XML files under the tag <MuscleFirstOrderActivationDynamicModel>. This property was generated with the OpenSim_DECLARE_UNNAMED_PROPERTY macro; see Property to learn about the property system.

See also
get_MuscleFirstOrderActivationDynamicModel(), upd_MuscleFirstOrderActivationDynamicModel(), set_MuscleFirstOrderActivationDynamicModel()

◆ tendon_force_length_damping

double OpenSim::Millard2012AccelerationMuscle::tendon_force_length_damping

"tendon force length damping coefficient"

This property appears in XML files under the tag <tendon_force_length_damping>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.

See also
get_tendon_force_length_damping(), upd_tendon_force_length_damping(), set_tendon_force_length_damping()

◆ TendonForceLengthCurve

TendonForceLengthCurve OpenSim::Millard2012AccelerationMuscle::TendonForceLengthCurve

"Tendon force length curve"

This property appears in XML files under the tag <TendonForceLengthCurve>. This property was generated with the OpenSim_DECLARE_UNNAMED_PROPERTY macro; see Property to learn about the property system.

See also
get_TendonForceLengthCurve(), upd_TendonForceLengthCurve(), set_TendonForceLengthCurve()

The documentation for this class was generated from the following file: