OpenSim::ExternalForce Class Reference

This applies a force and/or torque to a body according describe by arrays contained in a Storage The source of the Storage may be experimental sensor recording or user generated data. More...

#include <ExternalForce.h>

Inheritance diagram for OpenSim::ExternalForce:

List of all members.

Public Member Functions
	ExternalForce ()
	Default Construct of an ExternalForce.
	ExternalForce (const Storage &dataSource, std::string forceIdentifier="force", std::string PointIdentifier="point", std::string torqueIdentifier="torque", std::string appliedToBodyName="", std::string forceExpressedInBodyName="ground", std::string pointExpressedInBodyName="ground")
	Convenience Constructor of an ExternalForce.
	ExternalForce (const ExternalForce &force)
	Copy constructor.
	ExternalForce (DOMElement *aNode)
	Constructor from XML file.
	~ExternalForce ()
	Destructor.
virtual Object *	copy () const
	Copy this force and return a pointer to the copy.
virtual void	updateFromXMLNode ()
	Update this object based on its XML node.
void	setDataSource (const Storage *dataSource)
	Associate the data source from which the force, point and/or torque data is to be extracted.
void	setAppliedToBodyName (const std::string &applyToName) const
	Specify or obtain the body to which the force will be applied.
const std::string &	getAppliedToBodyName () const
void	setPointExpressedInBodyName (const std::string &pointInBodyName) const
	Specify or obtain the body in which the point of application is expressed.
const std::string &	getPointExpressedInBodyName () const
void	setForceExpressedInBodyName (const std::string &forceInBodyName) const
	Specify or obtain the body in which the force is expressed.
const std::string &	getForceExpressedInBodyName () const
void	setForceIdentifier (const std::string aForceIdentifier)
	Identifiers.
void	setPointIdentifier (const std::string aPointIdentifier)
void	setTorqueIdentifier (const std::string aTorqueIdentifier)
const std::string &	getForceIdentifier () const
const std::string &	getPointIdentifier () const
const std::string &	getTorqueIdentifier () const
SimTK::Vec3	getForceAtTime (double aTime) const
	Convenience methods to access external forces at a given time.
SimTK::Vec3	getPointAtTime (double aTime) const
SimTK::Vec3	getTorqueAtTime (double aTime) const
virtual OpenSim::Array < std::string >	getRecordLabels () const
	Methods used for reporting.
virtual 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.
bool	appliesForce () const
	Methods to query the force properties to find out if it's a body vs.
bool	specifiesPoint () const
bool	appliesTorque () const
ExternalForce &	operator= (const ExternalForce &aForce)
	Assignment operator.
	OPENSIM_DECLARE_DERIVED (ExternalForce, Force)
Protected Member Functions
virtual void	setup (Model &model)
	ModelComponent interface.
virtual void	computeForce (const SimTK::State &state, SimTK::Vector_< SimTK::SpatialVec > &bodyForces, SimTK::Vector &generalizedForces) const
	Compute the force.
Protected Attributes
PropertyStr	_appliedToBodyNameProp
	The body that the external force(torque) is applied to.
std::string &	_appliedToBodyName
PropertyStr	_forceExpressedInBodyNameProp
	The body (reference frame) that the external force(torque) is expressed in.
std::string &	_forceExpressedInBodyName
PropertyStr	_pointExpressedInBodyNameProp
	The body (reference frame) that the point of force application is expressed.
std::string &	_pointExpressedInBodyName
PropertyStr	_dataSourceNameProp
	The name of the data source (Storage) that contains the force as data points in time.
std::string &	_dataSourceName
PropertyStr	_forceIdentifierProp
	The identifier (as part of its label) of the force data in the dataSource necessary to retrieve the force data from the dataSource.
std::string &	_forceIdentifier
PropertyStr	_pointIdentifierProp
	The identifier of the point data in the dataSource necessary to retieve the point data from the dataSource.
std::string &	_pointIdentifier
PropertyStr	_torqueIdentifierProp
	The identifier for the torque data in the dataSource necessary to retieve the torque data from the dataSource.
std::string &	_torqueIdentifier
Friends
class	ExternalLoads

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Detailed Description

This applies a force and/or torque to a body according describe by arrays contained in a Storage The source of the Storage may be experimental sensor recording or user generated data.

The Storage must be able to supply (1) array of time, (3) arrays for the x,y,z, components of force and/or torque in time. Optionaly (3) arrays for the point of force application in time. This Force must identify a force identifier (e.g. Force1.x Force1.y Force1.y) may be individual labels for force components but they are collectively identified (as "Force1"). Similarly, identifiers for torque and point are expected.

If an identifier is supplied and it cannot uniquely identify the quantity (force, torque, point) in the Storage an Excpetion is thrown.

An ExternalForce must apply either a force or a torque so both identifiers cannot be empty.

Author:

Ajay Seth

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Constructor & Destructor Documentation

ExternalForce::ExternalForce

(

)

Default Construct of an ExternalForce.

Default constructor.

By default ExternalForce has data source identified by name. By setup() time, Tool or modeler must setDataSource() on this Force for it to be able to apply any force. Otherwise, an exception is thrown.

OpenSim::ExternalForce::ExternalForce	(	const Storage &	dataSource,
		std::string	forceIdentifier = "force",
		std::string	PointIdentifier = "point",
		std::string	torqueIdentifier = "torque",
		std::string	appliedToBodyName = "",
		std::string	forceExpressedInBodyName = "ground",
		std::string	pointExpressedInBodyName = "ground"
	)

Convenience Constructor of an ExternalForce.

Parameters:

	dataSource	a storage containing the pertinent force data through time
	forceIdentifier	string used to access the force data in the dataSource
	pointIdentifier	string used to access the point of application of the force in dataSource
	torqueIdentifier	string used to access the force data in the dataSource
	appliedToBodyName	string used to specify the body to which the force is applied
	forceExpressedInBodyName	string used to define in which body the force is expressed
	pointExpressedInBodyName	string used to define the body in which the the point is expressed

ExternalForce::ExternalForce

(

const ExternalForce &

force

)

Copy constructor.

ExternalForce::ExternalForce

(

DOMElement *

aNode

)

Constructor from XML file.

ExternalForce::~ExternalForce

(

)

Destructor.

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Member Function Documentation

bool OpenSim::ExternalForce::appliesForce

(

)

const [inline]

Methods to query the force properties to find out if it's a body vs.

point force and/or if it applies a torque

bool OpenSim::ExternalForce::appliesTorque

(

)

const [inline]

void ExternalForce::computeForce	(	const SimTK::State &	state,
		SimTK::Vector_< SimTK::SpatialVec > &	bodyForces,
		SimTK::Vector &	generalizedForces
	)			const [protected, virtual]

Compute the force.

Reimplemented from OpenSim::Force.

Object * ExternalForce::copy

(

)

const [virtual]

Copy this force and return a pointer to the copy.

The copy constructor for this class is used.

Returns:

Pointer to a copy of this force.

Implements OpenSim::Force.

const std::string& OpenSim::ExternalForce::getAppliedToBodyName

(

)

const [inline]

Vec3 ExternalForce::getForceAtTime

(

double

aTime

)

const

Convenience methods to access external forces at a given time.

Conevenince methods to access prescribed force functions.

const std::string& OpenSim::ExternalForce::getForceExpressedInBodyName

(

)

const [inline]

const std::string& OpenSim::ExternalForce::getForceIdentifier

(

)

const [inline]

Vec3 ExternalForce::getPointAtTime

(

double

aTime

)

const

const std::string& OpenSim::ExternalForce::getPointExpressedInBodyName

(

)

const [inline]

const std::string& OpenSim::ExternalForce::getPointIdentifier

(

)

const [inline]

OpenSim::Array< std::string > ExternalForce::getRecordLabels

(

)

const [virtual]

Methods used for reporting.

First identify the labels for individual components

Reimplemented from OpenSim::Force.

OpenSim::Array< double > ExternalForce::getRecordValues

(

const SimTK::State &

state

)

const [virtual]

Given SimTK::State object extract all the values necessary to report forces, application location frame, etc.

used in conjunction with getRecordLabels and should return same size Array

Reimplemented from OpenSim::Force.

Vec3 ExternalForce::getTorqueAtTime

(

double

aTime

)

const

const std::string& OpenSim::ExternalForce::getTorqueIdentifier

(

)

const [inline]

OpenSim::ExternalForce::OPENSIM_DECLARE_DERIVED	(	ExternalForce	,
		Force
	)

ExternalForce & ExternalForce::operator=

(

const ExternalForce &

aForce

)

Assignment operator.

Returns:

Reference to this object.

Reimplemented from OpenSim::Force.

void OpenSim::ExternalForce::setAppliedToBodyName

(

const std::string &

applyToName

)

const [inline]

Specify or obtain the body to which the force will be applied.

void ExternalForce::setDataSource

(

const Storage *

dataSource

)

Associate the data source from which the force, point and/or torque data is to be extracted.

void OpenSim::ExternalForce::setForceExpressedInBodyName

(

const std::string &

forceInBodyName

)

const [inline]

Specify or obtain the body in which the force is expressed.

void OpenSim::ExternalForce::setForceIdentifier

(

const std::string

aForceIdentifier

)

[inline]

Identifiers.

void OpenSim::ExternalForce::setPointExpressedInBodyName

(

const std::string &

pointInBodyName

)

const [inline]

Specify or obtain the body in which the point of application is expressed.

void OpenSim::ExternalForce::setPointIdentifier

(

const std::string

aPointIdentifier

)

[inline]

void OpenSim::ExternalForce::setTorqueIdentifier

(

const std::string

aTorqueIdentifier

)

[inline]

void ExternalForce::setup

(

Model &

model

)

[protected, virtual]

ModelComponent interface.

Reimplemented from OpenSim::Force.

bool OpenSim::ExternalForce::specifiesPoint

(

)

const [inline]

void ExternalForce::updateFromXMLNode

(

)

[virtual]

Update this object based on its XML node.

Reimplemented from OpenSim::Object.

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Friends And Related Function Documentation

friend class ExternalLoads [friend]

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Member Data Documentation

std::string& OpenSim::ExternalForce::_appliedToBodyName [protected]

PropertyStr OpenSim::ExternalForce::_appliedToBodyNameProp [protected]

The body that the external force(torque) is applied to.

std::string& OpenSim::ExternalForce::_dataSourceName [protected]

PropertyStr OpenSim::ExternalForce::_dataSourceNameProp [protected]

The name of the data source (Storage) that contains the force as data points in time.

std::string& OpenSim::ExternalForce::_forceExpressedInBodyName [protected]

PropertyStr OpenSim::ExternalForce::_forceExpressedInBodyNameProp [protected]

The body (reference frame) that the external force(torque) is expressed in.

std::string& OpenSim::ExternalForce::_forceIdentifier [protected]

PropertyStr OpenSim::ExternalForce::_forceIdentifierProp [protected]

The identifier (as part of its label) of the force data in the dataSource necessary to retrieve the force data from the dataSource.

std::string& OpenSim::ExternalForce::_pointExpressedInBodyName [protected]

PropertyStr OpenSim::ExternalForce::_pointExpressedInBodyNameProp [protected]

The body (reference frame) that the point of force application is expressed.

std::string& OpenSim::ExternalForce::_pointIdentifier [protected]

PropertyStr OpenSim::ExternalForce::_pointIdentifierProp [protected]

The identifier of the point data in the dataSource necessary to retieve the point data from the dataSource.

std::string& OpenSim::ExternalForce::_torqueIdentifier [protected]

PropertyStr OpenSim::ExternalForce::_torqueIdentifierProp [protected]

The identifier for the torque data in the dataSource necessary to retieve the torque data from the dataSource.

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

• OpenSim/Simulation/Model/ExternalForce.h
• OpenSim/Simulation/Model/ExternalForce.cpp