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OpenSim::ClutchedPathSpring Class Reference

The ClutchedPathSpring is an actuator that has passive path spring behavior only when the clutch is engaged. More...

#include <ClutchedPathSpring.h>

Inheritance diagram for OpenSim::ClutchedPathSpring:
OpenSim::PathActuator OpenSim::Actuator OpenSim::Actuator_ OpenSim::Force OpenSim::ModelComponent OpenSim::Object

Public Member Functions

 ClutchedPathSpring ()
 
 ClutchedPathSpring (const std::string &name, double stiffness, double dissipation, double relaxationTau, double stretch0=0.0)
 Convenience constructor with ClutchedPathSpring parameters. More...
 
double getStiffness () const
 Spring stiffness in N/m when clutch is engaged. More...
 
void setStiffness (double stiffness)
 
double getDissipation () const
 Spring dissipation factor in s/m when clutch is engaged. More...
 
void setDissipation (double dissipation)
 
double getInitialStretch ()
 Initial spring stretch in m. More...
 
void setInitialStretch (double stretch0)
 
double getStretch (const SimTK::State &s) const
 The stretch in the PathSpring. More...
 
double getTension (const SimTK::State &s) const
 The tension generated by the PathSpring. More...
 
Property declarations

These are the serializable properties of the ClutchedPathSpring class.

 OpenSim_DECLARE_PROPERTY (stiffness, double,"The linear stiffness (N/m) of the ClutchedPathSpring")
 
 OpenSim_DECLARE_PROPERTY (dissipation, double,"The dissipation factor (s/m) of the ClutchedPathSpring")
 
 OpenSim_DECLARE_PROPERTY (relaxation_time_constant, double,"The time constant (s) for the spring to relax (go slack) after the clutch ""is disengaged (i.e. control == 0). If the clutch is re-engaged within the ""relaxation period there will be residual tension in the spring.")
 
 OpenSim_DECLARE_PROPERTY (initial_stretch, double,"The initial stretch (m) of the spring element. Note if the clucth is ""not engaged, the actuator will 'slip' until there is no stretch according ""to the relaxation_time_constant.")
 
- Public Member Functions inherited from OpenSim::PathActuator
 PathActuator ()
 
GeometryPathupdGeometryPath ()
 
const GeometryPathgetGeometryPath () const
 
virtual bool hasGeometryPath () const
 Return a flag indicating whether the Force is applied along a Path. More...
 
void setOptimalForce (double aOptimalForce)
 
double getOptimalForce () const
 
virtual double getLength (const SimTK::State &s) const
 
virtual double getLengtheningSpeed (const SimTK::State &s) const
 
virtual double getPower (const SimTK::State &s) const
 
virtual double getStress (const SimTK::State &s) const
 
void addNewPathPoint (const std::string &proposedName, OpenSim::Body &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...
 
virtual void computeForce (const SimTK::State &state, SimTK::Vector_< SimTK::SpatialVec > &bodyForces, SimTK::Vector &mobilityForces) const
 Subclasses must implement this method to compute the forces that should be applied to bodies and generalized speeds. More...
 
virtual double computeMomentArm (const SimTK::State &s, Coordinate &aCoord) const
 
virtual void updateFromXMLNode (SimTK::Xml::Element &aNode, int versionNumber=-1)
 Use this method to deserialize an object from a SimTK::Xml::Element. More...
 
virtual void preScale (const SimTK::State &s, const ScaleSet &aScaleSet)
 
virtual void scale (const SimTK::State &s, const ScaleSet &aScaleSet)
 
virtual void postScale (const SimTK::State &s, const ScaleSet &aScaleSet)
 
virtual const VisibleObjectgetDisplayer () const
 Methods to support making the object displayable in the GUI or Visualizer Implemented only in few objects. More...
 
virtual void updateDisplayer (const SimTK::State &s) const
 In case the ModelComponent has a visual representation (VisualObject), override this method to update it. More...
 
 OpenSim_DECLARE_UNNAMED_PROPERTY (GeometryPath,"The set of points defining the path of the muscle.")
 
 OpenSim_DECLARE_PROPERTY (optimal_force, double,"The maximum force this actuator can produce.")
 
- Public Member Functions inherited from OpenSim::Actuator
 Actuator ()
 
virtual double getControl (const SimTK::State &s) const
 Convenience method to set controls given scalar (double) valued control. More...
 
virtual int numControls () const
 
virtual void setForce (const SimTK::State &s, double aForce) const
 
virtual double getForce (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)
 
double getMinControl () const
 
void setMaxControl (const double &aMaxControl)
 
double getMaxControl () const
 
void overrideForce (SimTK::State &s, bool flag) const
 Enable/disable an Actuator's override force. More...
 
bool isForceOverriden (const SimTK::State &s) const
 return Actuator's override status More...
 
void setOverrideForce (SimTK::State &s, double value) const
 set the force value used when the override is true More...
 
double getOverrideForce (const SimTK::State &s) const
 return override force More...
 
 OpenSim_DECLARE_PROPERTY (min_control, double,"Minimum allowed value for control signal. Used primarily when solving ""for control values.")
 Default is -Infinity (no limit). More...
 
 OpenSim_DECLARE_PROPERTY (max_control, double,"Maximum allowed value for control signal. Used primarily when solving ""for control values.")
 Default is Infinity (no limit). 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...
 
virtual void computeEquilibrium (SimTK::State &s) const
 
- Public Member Functions inherited from OpenSim::Force
 Force (const Force &aForce)
 Implements a copy constructor just so it can invalidate the SimTK::Force index after copying. More...
 
Forceoperator= (const Force &aForce)
 Implements a copy assignment operator just so it can invalidate the SimTK::Force index after the assignment. More...
 
bool isDisabled (const SimTK::State &s) const
 Return if the Force is disabled or not. More...
 
void setDisabled (SimTK::State &s, bool disabled) const
 Set the Force as disabled (true) or not (false). More...
 
 OpenSim_DECLARE_PROPERTY (isDisabled, bool,"Flag indicating whether the force is disabled or not. Disabled means"" that the force is not active in subsequent dynamics realizations.")
 A Force element is active (enabled) by default. More...
 
- Public Member Functions inherited from OpenSim::ModelComponent
 ModelComponent ()
 Default constructor. More...
 
 ModelComponent (const std::string &aFileName, bool aUpdateFromXMLNode=true) SWIG_DECLARE_EXCEPTION
 Construct ModelComponent from an XML file. More...
 
 ModelComponent (SimTK::Xml::Element &aNode)
 Construct ModelComponent from a specific node in an XML document. More...
 
 ModelComponent (const ModelComponent &source)
 Construct ModelComponent with its contents copied from another ModelComponent; this is a deep copy so nothing is shared with the source after the copy. More...
 
virtual ~ModelComponent ()
 Destructor is virtual to allow concrete model component cleanup. More...
 
ModelComponentoperator= (const ModelComponent &aModelComponent)
 Assignment operator to copy contents of an existing component. 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...
 
virtual int getNumStateVariables () const
 Get the number of "Continuous" state variables maintained by the ModelComponent and its specified subcomponents. More...
 
int getModelingOption (const SimTK::State &state, const std::string &name) const
 Get a ModelingOption flag for this ModelComponent by name. More...
 
void setModelingOption (SimTK::State &state, const std::string &name, int flag) const
 Set the value of a ModelingOption flag for this ModelComponent. More...
 
double getStateVariable (const SimTK::State &state, const std::string &name) const
 Get the value of a state variable allocated by this ModelComponent. More...
 
void setStateVariable (SimTK::State &state, const std::string &name, double value) const
 Set the value of a state variable allocated by this ModelComponent by name. More...
 
double getDiscreteVariable (const SimTK::State &state, const std::string &name) const
 Get the value of a discrete variable allocated by this ModelComponent by name. More...
 
void setDiscreteVariable (SimTK::State &state, const std::string &name, double value) const
 Set the value of a discrete variable allocated by this ModelComponent by name. More...
 
template<typename T >
const T & getCacheVariable (const SimTK::State &state, const std::string &name) const
 Get the value of a cache variable allocated by this ModelComponent by name. More...
 
template<typename T >
T & updCacheVariable (const SimTK::State &state, const std::string &name) const
 Obtain a writable cache variable value allocated by this ModelComponent by name. More...
 
void markCacheVariableValid (const SimTK::State &state, const std::string &name) const
 After updating a cache variable value allocated by this ModelComponent, you can mark its value as valid, which will not change until the realization stage falls below the minimum set at the time the cache variable was created. More...
 
void markCacheVariableInvalid (const SimTK::State &state, const std::string &name) const
 Mark a cache variable value allocated by this ModelComponent as invalid. More...
 
bool isCacheVariableValid (const SimTK::State &state, const std::string &name) const
 Enables the to monitor the validity of the cache variable value using the returned flag. More...
 
template<typename T >
void setCacheVariable (const SimTK::State &state, const std::string &name, const T &value) const
 Set cache variable value allocated by this ModelComponent by name. More...
 
- Public Member Functions inherited from OpenSim::Object
virtual ~Object ()
 Virtual destructor for cleanup. More...
 
virtual Objectclone () const =0
 Create a new heap-allocated copy of the concrete object to which this Object refers. More...
 
virtual const std::string & getConcreteClassName () const =0
 Returns the class name of the concrete Object-derived class of the actual object referenced by this Object, as a string. More...
 
virtual VisibleObjectupdDisplayer ()
 get Non const pointer to VisibleObject 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, call this method in your constructor if needed. 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...
 
void setObjectIsUpToDateWithProperties ()
 When an object is initialized using the current values of its properties, it can set a flag indicating that it is up to date. 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...
 
virtual void updateXMLNode (SimTK::Xml::Element &parent)
 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...
 
void setAllPropertiesUseDefault (bool aUseDefault)
 
bool print (const std::string &fileName)
 Write this Object into an XML file of the given name; conventionally the suffix to use is ".osim". More...
 
std::string dump (bool dumpName=false)
 dump the XML representation of this Object into an std::string and return it. More...
 
void clearObjectIsUpToDateWithProperties ()
 For testing or debugging purposes, manually clear the "object is up to date with respect to properties" flag. 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
 

Protected Member Functions

double computeActuation (const SimTK::State &s) const override
 
SimTK::Vec3 computePathColor (const SimTK::State &state) const override
 Override PathActuator method to calculate a color for use when the ClutchedPathSpring's path is displayed in the visualizer. More...
 
void addToSystem (SimTK::MultibodySystem &system) const override
 Implement ModelComponent interface. More...
 
void initStateFromProperties (SimTK::State &state) const override
 Subclass should override; be sure to invoke Force::initStateFromProperties() at the beginning of the overriding method. More...
 
void setPropertiesFromState (const SimTK::State &state) override
 Subclass should override; be sure to invoke Force::setPropertiesFromState() at the beginning of the overriding method. More...
 
Array< std::string > getStateVariableNames () const override
 Get the names of "continuous" state variables maintained by the ModelComponent and its subcomponents. More...
 
SimTK::SystemYIndex getStateVariableSystemIndex (const std::string &stateVariableName) const override
 Get the System Index of a state variable allocated by this ModelComponent. More...
 
SimTK::Vector computeStateVariableDerivatives (const SimTK::State &s) const override
 If a model component has allocated any continuous state variables using the addStateVariable() method, then computeStateVariableDerivatives() must be implemented to provide time derivatives for those states. More...
 
- Protected Member Functions inherited from OpenSim::PathActuator
void connectToModel (Model &aModel) override
 Extension of parent class method; derived classes may extend further. More...
 
void realizeDynamics (const SimTK::State &state) const override
 Extension of parent class method; derived classes may extend further. More...
 
- Protected Member Functions inherited from OpenSim::Actuator
double computeOverrideForce (const SimTK::State &s) const
 
OpenSim::Array< std::string > getRecordLabels () const
 Methods to query a Force for the value actually applied during simulation The names of the quantities (column labels) is returned by this first function getRecordLabels() More...
 
OpenSim::Array< double > getRecordValues (const SimTK::State &state) const
 Given SimTK::State object extract all the values necessary to report forces, application location frame, etc. More...
 
- Protected Member Functions inherited from OpenSim::Actuator_
virtual void updateGeometry ()
 
- Protected Member Functions inherited from OpenSim::Force
 Force ()
 Default constructor sets up Force-level properties; can only be called from a derived class constructor. More...
 
 Force (SimTK::Xml::Element &node)
 Deserialization from XML, necessary so that derived classes can (de)serialize. More...
 
virtual double computePotentialEnergy (const SimTK::State &state) const
 Subclasses may optionally override this method to compute a contribution to the potential energy of the system. More...
 
void applyForceToPoint (const SimTK::State &state, const OpenSim::Body &body, const SimTK::Vec3 &point, const SimTK::Vec3 &force, SimTK::Vector_< SimTK::SpatialVec > &bodyForces) const
 Apply a force at a particular point (a "station") on a given body. More...
 
void applyTorque (const SimTK::State &state, const OpenSim::Body &body, const SimTK::Vec3 &torque, SimTK::Vector_< SimTK::SpatialVec > &bodyForces) const
 Apply a torque to a particular body. More...
 
void applyGeneralizedForce (const SimTK::State &state, const Coordinate &coord, double force, SimTK::Vector &generalizedForces) const
 Apply a generalized force. More...
 
- Protected Member Functions inherited from OpenSim::ModelComponent
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 ModelComponent at the specified state. More...
 
virtual void realizeTopology (SimTK::State &state) const
 Obtain state resources that are needed unconditionally, and perform computations that depend only on the system topology. More...
 
virtual void realizeModel (SimTK::State &state) const
 Obtain state resources that may be needed, depending on modeling options, and perform computations that depend only on topology and selected modeling options. More...
 
virtual void realizeInstance (const SimTK::State &state) const
 Perform computations that depend only on instance variables, like lengths and masses. More...
 
virtual void realizeTime (const SimTK::State &state) const
 Perform computations that depend only on time and earlier stages. More...
 
virtual void realizePosition (const SimTK::State &state) const
 Perform computations that depend only on position-level state variables and computations performed in earlier stages (including time). More...
 
virtual void realizeVelocity (const SimTK::State &state) const
 Perform computations that depend only on velocity-level state variables and computations performed in earlier stages (including position, and time). More...
 
virtual void realizeAcceleration (const SimTK::State &state) const
 Perform computations that may depend on applied forces. More...
 
virtual void realizeReport (const SimTK::State &state) const
 Perform computations that may depend on anything but are only used for reporting and cannot affect subsequent simulation behavior. More...
 
void includeAsSubComponent (ModelComponent *aComponent)
 Include another ModelComponent as a Subcomponent of this ModelComponent. More...
 
void addModelingOption (const std::string &optionName, int maxFlagValue) const
 Add a modeling option (integer flag stored in the State) for use by this ModelComponent. More...
 
void addStateVariable (const std::string &stateVariableName, SimTK::Stage invalidatesStage=SimTK::Stage::Dynamics) const
 Add a continuous system state variable belonging to this ModelComponent, and assign a name by which to refer to it. More...
 
void addDiscreteVariable (const std::string &discreteVariableName, SimTK::Stage invalidatesStage) const
 Add a system discrete variable belonging to this ModelComponent, give it a name by which it can be referenced, and declare the lowest Stage that should be invalidated if this variable's value is changed. More...
 
template<class T >
void addCacheVariable (const std::string &cacheVariableName, const T &variablePrototype, SimTK::Stage dependsOnStage) const
 Add a state cache entry belonging to this ModelComponent to hold calculated values that must be automatically invalidated when certain state values change. More...
 
const int getStateIndex (const std::string &name) const
 Get the index of a ModelComponent's continuous state variable in the Subsystem for allocations. More...
 
const SimTK::DiscreteVariableIndex getDiscreteVariableIndex (const std::string &name) const
 Get the index of a ModelComponent's discrete variable in the Subsystem for allocations. More...
 
const SimTK::CacheEntryIndex getCacheVariableIndex (const std::string &name) const
 Get the index of a ModelComponent's cache variable in the Subsystem for allocations. More...
 
- Protected Member Functions inherited from OpenSim::Object
 Object ()
 The default constructor is only for use by constructors of derived types. More...
 
 Object (const std::string &fileName, bool aUpdateFromXMLNode=true) SWIG_DECLARE_EXCEPTION
 Constructor from a file, to be called from other constructors that take a file as input. More...
 
 Object (const Object &source)
 Copy constructor is invoked automatically by derived classes with default copy constructors; otherwise it must be invoked explicitly. More...
 
 Object (SimTK::Xml::Element &aElement)
 Construct the base class portion of an Object from a given Xml element that describes this Object. More...
 
template<class T >
PropertyIndex addProperty (const std::string &name, const std::string &comment, const T &value)
 Define a new single-value property of known type T, with the given name, associated comment, and initial value. More...
 
template<class T >
PropertyIndex addOptionalProperty (const std::string &name, const std::string &comment)
 Add an optional property, meaning it can contain either no value or a single value. More...
 
template<class T >
PropertyIndex addOptionalProperty (const std::string &name, const std::string &comment, const T &value)
 Add an optional property, meaning it can contain either no value or a single value. More...
 
template<class T >
PropertyIndex addListProperty (const std::string &name, const std::string &comment, int minSize, int maxSize)
 Define a new list-valued property of known type T, with the given name, associated comment, minimum (==0) and maximum (>0) allowable list lengths, and a zero-length initial value. More...
 
template<class T , template< class > class Container>
PropertyIndex addListProperty (const std::string &name, const std::string &comment, int minSize, int maxSize, const Container< T > &valueList)
 Define a new list-valued property as above, but assigning an initial value via some templatized container class that supports size() and indexing. More...
 
PropertyIndex getPropertyIndex (const std::string &name) const
 Look up a property by name and return its PropertyIndex if it is found. More...
 
template<class T >
PropertyIndex getPropertyIndex () const
 Look up an unnamed property by the type of object it contains, and return its PropertyIndex if it is found. More...
 
void updateFromXMLDocument ()
 Use this method only if you're deserializing from a file and the object is at the top level; that is, primarily in constructors that take a file name as input. More...
 
void setDocument (XMLDocument *doc)
 Unconditionally set the XMLDocument associated with this object. More...
 
const XMLDocumentgetDocument () const
 Get a const pointer to the document (if any) associated with this object. More...
 
XMLDocumentupdDocument ()
 Get a writable pointer to the document (if any) associated with this object. More...
 

Additional Inherited Members

- 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 void PrintPropertyInfo (std::ostream &os, const std::string &classNameDotPropertyName)
 Dump formatted property information to a given output stream, useful for creating a "help" facility for registered objects. More...
 
static void PrintPropertyInfo (std::ostream &os, const std::string &className, const std::string &propertyName)
 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 debug level to get verbose output. More...
 
static int getDebugLevel ()
 Get 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...
 
- Static Public Attributes inherited from OpenSim::Object
static const std::string DEFAULT_NAME
 Name used for default objects when they are serialized. More...
 
- Protected Attributes inherited from OpenSim::Actuator_
int _controlIndex
 

Detailed Description

The ClutchedPathSpring is an actuator that has passive path spring behavior only when the clutch is engaged.

The clutch is engaged by a control signal of 1 and is off for a control signal of 0. Off means the spring is not engaged and the path is free to change length with the motion of the bodies it is connected to. The tension produced by the spring is proportional to the stretch (z) from the instant that the clutch is engaged.

The spring tension = x*(K*z)*(1+D*Ldot), where

  • x is the control signal to the actuator
  • z is the stretch in the spring
  • Ldot is the lengthening speed of the actuator
  • K is the spring's linear stiffness (N/m)
  • D is the spring's dissipation factor

The ClutchedPathSpring maintains the "stretch", z, as an internal state with the following dynamics:

dz/dt = Ldot, when x>0 (clutch is engaged)
-(1/Tau)*z, (decay to zero), otherwise

Note that the control signal, x, is clamped to (0,1).

Author
Ajay Seth

Constructor & Destructor Documentation

OpenSim::ClutchedPathSpring::ClutchedPathSpring ( )
OpenSim::ClutchedPathSpring::ClutchedPathSpring ( const std::string &  name,
double  stiffness,
double  dissipation,
double  relaxationTau,
double  stretch0 = 0.0 
)

Convenience constructor with ClutchedPathSpring parameters.

Parameters
namethe name of a ClutchedPathSpring instance
stiffnessthe spring stiffness (K) in N/m
dissipationthe dissipation factor (D) in s/m
relaxationTauthe spring relaxation time constant (Tau) in s
stretch0the initial stretch of the spring in m

Member Function Documentation

void OpenSim::ClutchedPathSpring::addToSystem ( SimTK::MultibodySystem &  system) const
overrideprotectedvirtual

Implement ModelComponent interface.

Reimplemented from OpenSim::Actuator.

double OpenSim::ClutchedPathSpring::computeActuation ( const SimTK::State &  s) const
overrideprotectedvirtual

Reimplemented from OpenSim::PathActuator.

SimTK::Vec3 OpenSim::ClutchedPathSpring::computePathColor ( const SimTK::State &  state) const
overrideprotectedvirtual

Override PathActuator method to calculate a color for use when the ClutchedPathSpring's path is displayed in the visualizer.

Parameters
[in]stateA SimTK::State already realized through Stage::Velocity. Do not attempt to realize it any further.
Returns
The desired color for the path as an RGB vector with each component ranging from 0 to 1, or NaN to indicate that the color should not be changed.

Reimplemented from OpenSim::PathActuator.

SimTK::Vector OpenSim::ClutchedPathSpring::computeStateVariableDerivatives ( const SimTK::State &  s) const
overrideprotectedvirtual

If a model component has allocated any continuous state variables using the addStateVariable() method, then computeStateVariableDerivatives() must be implemented to provide time derivatives for those states.

Override to return a Vector of the same size as the number of state variables defined and in order added to the system (also

See Also
addToSystem()). Default returns empty (no derivatives are defined). Implement like this:
SimTK::Vector computeStateVariableDerivatives(const SimTK::State& s) const {
// Collect derivatives from parent class and above first.
SimTK::Vector derivs = Super::computeStateVariableDerivatives(s);
const int n = derivs.size();
derivs.resizeKeep(n + myNumStateVariables); // grow
for (int i=0; i < myNumStateVariables; ++i)
derivs[n+i] = ...; // i'th state variable derivative
return derivs;
}
This method is invoked from the base class realizeAcceleration() method.

Reimplemented from OpenSim::ModelComponent.

double OpenSim::ClutchedPathSpring::getDissipation ( ) const
inline

Spring dissipation factor in s/m when clutch is engaged.

double OpenSim::ClutchedPathSpring::getInitialStretch ( )
inline

Initial spring stretch in m.

Array<std::string> OpenSim::ClutchedPathSpring::getStateVariableNames ( ) const
overrideprotectedvirtual

Get the names of "continuous" state variables maintained by the ModelComponent and its subcomponents.

Reimplemented from OpenSim::ModelComponent.

SimTK::SystemYIndex OpenSim::ClutchedPathSpring::getStateVariableSystemIndex ( const std::string &  stateVariableName) const
overrideprotectedvirtual

Get the System Index of a state variable allocated by this ModelComponent.

Returns an InvalidIndex if no state variable with the name provided is found.

Parameters
stateVariableNamethe name of the state variable

Reimplemented from OpenSim::ModelComponent.

double OpenSim::ClutchedPathSpring::getStiffness ( ) const
inline

Spring stiffness in N/m when clutch is engaged.

double OpenSim::ClutchedPathSpring::getStretch ( const SimTK::State &  s) const

The stretch in the PathSpring.

The value of the stretch can only be obtained after the system has been realized to Stage::Position

double OpenSim::ClutchedPathSpring::getTension ( const SimTK::State &  s) const

The tension generated by the PathSpring.

The value of the tension can only be obtained after the system has been realized to Stage::Dynamics

void OpenSim::ClutchedPathSpring::initStateFromProperties ( SimTK::State &  state) const
overrideprotectedvirtual

Subclass should override; be sure to invoke Force::initStateFromProperties() at the beginning of the overriding method.

Reimplemented from OpenSim::Force.

OpenSim::ClutchedPathSpring::OpenSim_DECLARE_PROPERTY ( stiffness  ,
double  ,
"The linear stiffness (N/m) of the ClutchedPathSpring  
)
OpenSim::ClutchedPathSpring::OpenSim_DECLARE_PROPERTY ( dissipation  ,
double  ,
"The dissipation factor (s/m) of the ClutchedPathSpring  
)
OpenSim::ClutchedPathSpring::OpenSim_DECLARE_PROPERTY ( relaxation_time_constant  ,
double  ,
"The time constant (s) for the spring to relax (go slack) after the clutch ""is disengaged (i.e. control == 0). If the clutch is re-engaged within the ""relaxation period there will be residual tension in the spring."   
)
OpenSim::ClutchedPathSpring::OpenSim_DECLARE_PROPERTY ( initial_stretch  ,
double  ,
"The initial stretch (m) of the spring element. Note if the clucth is ""not  engaged,
the actuator will 'slip'until there is no stretch according""to the relaxation_time_constant."   
)
void OpenSim::ClutchedPathSpring::setDissipation ( double  dissipation)
void OpenSim::ClutchedPathSpring::setInitialStretch ( double  stretch0)
void OpenSim::ClutchedPathSpring::setPropertiesFromState ( const SimTK::State &  state)
overrideprotectedvirtual

Subclass should override; be sure to invoke Force::setPropertiesFromState() at the beginning of the overriding method.

Reimplemented from OpenSim::Force.

void OpenSim::ClutchedPathSpring::setStiffness ( double  stiffness)

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