Minimize the error between compliant contact force elements in the model and experimentally measured contact forces. More...

Inheritance diagram for OpenSim::MocoContactTrackingGoal:

Public Member Functions
	MocoContactTrackingGoal ()

	MocoContactTrackingGoal (std::string name)

	MocoContactTrackingGoal (std::string name, double weight)

void	setExternalLoadsFile (const std::string &extLoadsFile)
	Set the ExternalLoads as an XML file. More...

void	setExternalLoads (const ExternalLoads &extLoads)
	Set the ExternalLoads as an object. More...

void	addContactGroup (const std::vector< std::string > &contactForcePaths, const std::string &externalForceName)
	Add a group of contact forces whose sum should track the force data from a single ExternalForce. More...

void	addContactGroup (MocoContactTrackingGoalGroup group)
	Add a group of contact forces whose sum should track the force data from a single ExternalForce. More...

void	setProjection (std::string projection)
	Set if the force error should be projected onto either a vector or plane. More...

std::string	getProjection () const

void	setProjectionVector (SimTK::Vec3 normal)
	Set the vector to use for projecting the force error. More...

void	clearProjectionVector ()
	Unset the projection vector. More...

SimTK::Vec3	getProjectionVector () const

Public Member Functions inherited from OpenSim::MocoGoal
	MocoGoal ()

	MocoGoal (std::string name)

	MocoGoal (std::string name, double weight)

void	setEnabled (bool enabled)
	Set whether this goal is used in the problem. More...

bool	getEnabled () const

void	setWeight (double weight)
	In cost mode, the goal is multiplied by this weight. More...

double	getWeight () const

void	setMode (std::string mode)
	Set the mode property to either 'cost' or 'endpoint_constraint'. More...

std::string	getModeAsString () const
	This returns the default mode of the goal, unless the user overrode the default using setMode(). More...

Mode	getMode () const

bool	getModeIsCost () const

bool	getModeIsEndpointConstraint () const

Mode	getDefaultMode () const
	Types of goals have a class-level default for whether they are enforced as a cost or endpoint constraint. More...

bool	getSupportsEndpointConstraint () const
	Can this goal be used in endpoint constraint mode? More...

const MocoConstraintInfo &	getConstraintInfo () const
	Get bounds for the constraints that are enforced when using this goal in endpoint constraint mode. More...

MocoConstraintInfo &	updConstraintInfo ()

int	getNumOutputs () const
	Get the length of the return value of calcGoal(). More...

int	getNumIntegrals () const
	Get the number of integrals required by this cost. More...

SimTK::Stage	getStageDependency () const
	Obtain the stage that this goal depends on. More...

SimTK::Real	calcIntegrand (const IntegrandInput &input) const
	Calculate the integrand that should be integrated and passed to calcCost(). More...

void	calcGoal (const GoalInput &input, SimTK::Vector &goal) const
	In cost mode, the returned cost includes the weight, and the elements of the returned vector should be summed by the caller to obtain the total cost. More...

void	initializeOnModel (const Model &model) const
	Perform error checks on user input for this goal, and cache quantities needed when computing the goal value. More...

void	printDescription () const
	Print the name type and mode of this goal. 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...

Object &	operator= (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 AbstractProperty &	getPropertyByIndex (int propertyIndex) const
	Get a const reference to a property by its index number, returned as an AbstractProperty. More...

AbstractProperty &	updPropertyByIndex (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 AbstractProperty &	getPropertyByName (const std::string &name) const
	Get a const reference to a property by its name, returned as an AbstractProperty. More...

AbstractProperty &	updPropertyByName (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...

virtual void	updateFromXMLNode (SimTK::Xml::Element &objectElement, int versionNumber)
	Use this method to deserialize an object from a SimTK::Xml::Element. 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...

PropertySet &	getPropertySet ()
	OBSOLETE: Get a reference to the PropertySet maintained by the Object. More...

const PropertySet &	getPropertySet () const

Static Public Member Functions
Auto-generated functions
static MocoContactTrackingGoal *	safeDownCast (OpenSim::Object *obj)
	For use in MATLAB and Python to access the concrete class. More...

Static Public Member Functions inherited from OpenSim::MocoGoal
static MocoGoal *	safeDownCast (OpenSim::Object *obj)
	For use in MATLAB and Python to access the concrete class. More...

static const std::string &	getClassName ()
	This returns "MocoGoal" 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 Object *	getDefaultInstanceOfType (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 Object *	newInstanceOfType (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 Object *	makeObjectFromFile (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 Object *	SafeCopy (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...

Auto-generated functions <br>
static const std::string &	getClassName ()
	This returns "MocoContactTrackingGoal" More...

MocoContactTrackingGoal *	clone () 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...

Detailed Description

Minimize the error between compliant contact force elements in the model and experimentally measured contact forces.

This class handles multiple groups of contact forces and a single experimental external loads file. Tracking ground reaction forces for the left and right feet in gait requires only one instance of this goal.

Note: The only contact element supported is SmoothSphereHalfSpaceForce.; This goal does not include torques or centers of pressure.

This goal is computed as follows:

\[ \frac{1}{mg} \int_{t_i}^{t_f} \sum_{j \in G} \|\mathrm{proj}_{\hat{n}}(\vec{F}_{m,j} - \vec{F}_{e,j})\|^2 ~dt \]

We use the following notation:

\( t_i \): the initial time of this phase.
\( t_f \): the final time of this phase.
\( mg \): the total weight of the system; replaced with \( m \) if \( g = 0 \).
\( G \): the set of contact groups.
\( \hat{n} \): a vector used for projecting the force error.
\( \mathrm{proj}_{\hat{n}}() \): this function projects the force error either onto \( \hat{n} \) or onto the plane perpendicular to \( \hat{n} \).
\( \vec{F}_{m,j} \) the sum of the contact forces in group \( j \), expressed in ground.
\( \vec{F}_{e,j} \) the experimental contact force for group \( j \), expressed in ground.

Tracking a subset of force components

The projection is useful for selecting which components of the force to track. The force can be projected to be onto a vector or onto a plane. For example, with gait, projecting onto the vector (0, 1, 0) allows tracking only the vertical component of a ground reaction force; projecting onto the plane perpendicular to the vector (0, 0, 1) allows ignoring the transverse force. See the projection and projection_vector properties.

Usage

To use this goal, specify the following:

a single ExternalLoads file or object, which is a set of ExternalForces.
a set of contact groups, each of which contains the name of an ExternalForce (within the ExternalLoads).

Configuring the ExternalLoads

The ExternalLoads class is the standard way to provide experimental contact forces in OpenSim. This class is a set of ExternalForce objects. For gait, typically the ExternalLoads contains 2 ExternalForces, one for each foot. This goal uses the following information from ExternalLoads:

data_file: This scalar file contains all experimental force data with columns named according to each ExternalForce's force_identifier.

This goal uses the following information from each ExternalForce:

name: We use the name of the ExternalForce to associate it with a contact force group.
applied_on_body: All contact forces in the group with which this ExternalForce is associated must use this body as either the sphere_frame's base frame or the half_space_frame's base frame.
force_expressed_in_body: We use this to re-express the experimental force in ground. This is either the absolute path to a PhysicalFrame in the model, or the name of a Body in the model's BodySet.
force_identifier: The ExternalLoads data_file must include the 3 columns <force_identifier>x, <force_identifier>y, <force_identifier>z.

All other properties of ExternalLoads and ExternalForce are ignored by this goal. This means that experimental forces are processed differently by this goal than by other OpenSim tools such as Inverse Dynamics, Computed Muscle Control, and Forward.

Note: The ExternalLoads used by this goal is separate from the model. Using this goal implies that the model contains compliant contact forces, so adding ExternalLoads to the model would be redundant. This class uses the ExternalLoads only for computing the force error, not for applying forces to the model.

Constructor & Destructor Documentation

◆ MocoContactTrackingGoal() [1/3]

OpenSim::MocoContactTrackingGoal::MocoContactTrackingGoal ( )

inline

◆ MocoContactTrackingGoal() [2/3]

OpenSim::MocoContactTrackingGoal::MocoContactTrackingGoal ( std::string name )

inline

◆ MocoContactTrackingGoal() [3/3]

OpenSim::MocoContactTrackingGoal::MocoContactTrackingGoal	(	std::string	name,
		double	weight
	)

inline

Member Function Documentation

◆ addContactGroup() [1/2]

void OpenSim::MocoContactTrackingGoal::addContactGroup	(	const std::vector< std::string > &	contactForcePaths,
		const std::string &	externalForceName
	)

inline

Add a group of contact forces whose sum should track the force data from a single ExternalForce.

The externalForceName should be the name of an ExternalForce object in the ExternalLoads.

◆ addContactGroup() [2/2]

void OpenSim::MocoContactTrackingGoal::addContactGroup ( MocoContactTrackingGoalGroup group )

inline

Add a group of contact forces whose sum should track the force data from a single ExternalForce.

If the contact force elements associated with a single ExternalForce are distributed across multiple bodies use this function instead of the easier-to-use addContactGroup(), and set the group's alternative_frame_paths property accordingly. See MocoContactTrackingGoalGroup for more information.

◆ calcGoalImpl()

void OpenSim::MocoContactTrackingGoal::calcGoalImpl	(	const GoalInput &	input,
		SimTK::Vector &	goal
	)		const

inlineoverrideprotectedvirtual

You may need to realize the state to the stage required for your calculations.

Do NOT realize to a stage higher than the goal's stage dependency; doing so will cause an exception to be thrown. The Lagrange multipliers for kinematic constraints are not available.

Implements OpenSim::MocoGoal.

References OpenSim::MocoGoal::GoalInput::integral.

◆ calcIntegrandImpl()

void OpenSim::MocoContactTrackingGoal::calcIntegrandImpl	(	const IntegrandInput &	input,
		double &	integrand
	)		const

overrideprotected

◆ clearProjectionVector()

void OpenSim::MocoContactTrackingGoal::clearProjectionVector ( )

inline

Unset the projection vector.

◆ clone()

MocoContactTrackingGoal* OpenSim::MocoContactTrackingGoal::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::MocoGoal.

◆ getClassName()

static const std::string& OpenSim::MocoContactTrackingGoal::getClassName ( )

inlinestatic

This returns "MocoContactTrackingGoal"

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

◆ getConcreteClassName()

const std::string& OpenSim::MocoContactTrackingGoal::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::MocoGoal.

◆ getProjection()

std::string OpenSim::MocoContactTrackingGoal::getProjection ( ) const

inline

◆ getProjectionVector()

SimTK::Vec3 OpenSim::MocoContactTrackingGoal::getProjectionVector ( ) const

inline

◆ initializeOnModelImpl()

void OpenSim::MocoContactTrackingGoal::initializeOnModelImpl ( const Model & ) const

overrideprotectedvirtual

Perform any caching before the problem is solved.

You must override this function and invoke setRequirements().

Precondition(s):: The model is initialized (initSystem()) and getModel() is available. The passed-in model is equivalent to getModel(). Use this opportunity to check for errors in user input.

Implements OpenSim::MocoGoal.

◆ printDescriptionImpl()

void OpenSim::MocoContactTrackingGoal::printDescriptionImpl ( ) const

overrideprotectedvirtual

Print a more detailed description unique to each goal.

Reimplemented from OpenSim::MocoGoal.

◆ safeDownCast()

static MocoContactTrackingGoal* OpenSim::MocoContactTrackingGoal::safeDownCast ( OpenSim::Object * obj )

inlinestatic

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

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

◆ setExternalLoads()

void OpenSim::MocoContactTrackingGoal::setExternalLoads ( const ExternalLoads & extLoads )

Set the ExternalLoads as an object.

This clears the ExternalLoads XML file, if provided.

◆ setExternalLoadsFile()

void OpenSim::MocoContactTrackingGoal::setExternalLoadsFile ( const std::string & extLoadsFile )

Set the ExternalLoads as an XML file.

This clears the ExternalLoads provided as an object, if one exists.

◆ setProjection()

void OpenSim::MocoContactTrackingGoal::setProjection ( std::string projection )

inline

Set if the force error should be projected onto either a vector or plane.

Possible values: "none" (default), "vector", and "plane".

◆ setProjectionVector()

void OpenSim::MocoContactTrackingGoal::setProjectionVector ( SimTK::Vec3 normal )

inline

Set the vector to use for projecting the force error.

If the projection type is "vector", the force error is projected onto the vector provided here. If the projection type is "plane", the force error is projected onto the plane perpendicular to this vector.

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

OpenSim/Moco/MocoGoal/MocoContactTrackingGoal.h

Public Member Functions

Static Public Member Functions

Auto-generated functions <br>

Detailed Description

Tracking a subset of force components

Usage

Configuring the ExternalLoads

Constructor & Destructor Documentation

◆ MocoContactTrackingGoal() [1/3]

◆ MocoContactTrackingGoal() [2/3]

◆ MocoContactTrackingGoal() [3/3]

Member Function Documentation

◆ addContactGroup() [1/2]

◆ addContactGroup() [2/2]

◆ calcGoalImpl()

◆ calcIntegrandImpl()

◆ clearProjectionVector()

◆ clone()

◆ getClassName()

◆ getConcreteClassName()

◆ getProjection()

◆ getProjectionVector()

◆ initializeOnModelImpl()

◆ printDescriptionImpl()

◆ safeDownCast()

◆ setExternalLoads()

◆ setExternalLoadsFile()

◆ setProjection()

◆ setProjectionVector()