OpenSim::Constraint Class Reference

A parent class for implementing a Simbody Constraint. More...

#include <Constraint.h>

Inheritance diagram for OpenSim::Constraint:

Public Member Functions
	Constraint ()
	Default constructor.
	Constraint (const Constraint &aConstraint)
	Copy constructor.
virtual	~Constraint ()
	Destructor.
virtual Object *	copy () const =0
	Construct and return a copy of this object.
Constraint &	operator= (const Constraint &aConstraint)
	Assignment operator.
void	copyData (const Constraint &aConstraint)
	Copy data members from one Constraint to another.
virtual void	updateFromConstraint (SimTK::State &s, const Constraint &aConstraint)
	Update an existing Constraint with parameter values from a new one, but only for the parameters that were explicitly specified in the XML node.
virtual bool	isDisabled (const SimTK::State &s) const
	Get whether or not this Constraint is disabled.
virtual bool	setDisabled (SimTK::State &s, bool isDisabled)
	Set whether or not this Constraint is disabled.
virtual void	calcConstraintForces (const SimTK::State &s, SimTK::Vector_< SimTK::SpatialVec > &bodyForcesInAncestor, SimTK::Vector &mobilityForces) const
	Ask the constraint for the forces it is imposing on the system Simbody multibody system must be realized to at least position Returns: the bodyForces on those bodies being constrained (constrainedBodies) a SpatialVec (6 components) describing resulting torque and force mobilityForces acting along constrained mobilities.
virtual Array< std::string >	getRecordLabels () const
	Methods to query a Constraint forces (defaults to the Lagrange mulipliers) applied The names of the quantities (column labels) is returned by this first function getRecordLabels().
virtual Array< double >	getRecordValues (const SimTK::State &state) const
	Given SimTK::State object extract all the values necessary to report constraint forces (multipliers) Subclasses can override to report force, application location frame, etc.
virtual void	scale (const ScaleSet &aScaleSet)
virtual void	setContactPointForInducedAccelerations (const SimTK::State &s, SimTK::Vec3 point)
	This method specifies the interface that a constraint must implement in order to be used by the Induced Accelerations Analysis.
	OPENSIM_DECLARE_DERIVED (Constraint, Object)
Protected Member Functions
virtual void	setup (Model &aModel)
	Perform some set up functions that happen after the object has been deserialized or copied.
virtual void	initState (SimTK::State &state) const
	This is called after a SimTK System and State have been created for the Model.
virtual void	setDefaultsFromState (const SimTK::State &state)
	Set all default values for this object to match those in a specified State.
virtual int	getNumStateVariables () const
	Gets the number of "Continuous" state variables maintained by the ModelComponent If the ModelComponent defines any that are of interest to the user, names should also be given.
Protected Attributes
PropertyBool	_isDisabledProp
	Flag indicating whether the constraint is disabled or not.
SimTK::ConstraintIndex	_index
	ID for the constraint in Simbody.
Friends
class	SimbodyEngine

Detailed Description

A parent class for implementing a Simbody Constraint.

Specific constraints should be derived from this class.

Author:: Frank C. Anderson; Ajay Seth

Version:: 1.0

Constructor & Destructor Documentation

Constraint::Constraint ( )

Default constructor.

Constraint::Constraint ( const Constraint & aConstraint )

Copy constructor.

Parameters:

aConstraint

Constraint to be copied.

Constraint::~Constraint ( ) [virtual]

Destructor.

Member Function Documentation

void Constraint::calcConstraintForces	(	const SimTK::State &	s,
		SimTK::Vector_< SimTK::SpatialVec > &	bodyForcesInAncestor,
		SimTK::Vector &	mobilityForces
	)			const `[virtual]`

Ask the constraint for the forces it is imposing on the system Simbody multibody system must be realized to at least position Returns: the bodyForces on those bodies being constrained (constrainedBodies) a SpatialVec (6 components) describing resulting torque and force mobilityForces acting along constrained mobilities.

Parameters:

	state	State of model
	bodyForcesInAncestor	is a Vector of SpatialVecs contain constraint forces
	mobilityForces	is a Vector of forces that act along the constrained mobilitities associated with this constraint

Reimplemented in OpenSim::RollingOnSurfaceConstraint.

virtual Object* OpenSim::Constraint::copy ( ) const [pure virtual]

Construct and return a copy of this object.

The object is allocated using the new operator, so the caller is responsible for deleting the returned object.

Returns:: Copy of this object.

Reimplemented from OpenSim::Object.

Implemented in OpenSim::CoordinateCouplerConstraint, OpenSim::PointConstraint, OpenSim::PointOnLineConstraint, OpenSim::RollingOnSurfaceConstraint, OpenSim::UnilateralConstraint, and OpenSim::WeldConstraint.

void Constraint::copyData ( const Constraint & aConstraint )

Copy data members from one Constraint to another.

Parameters:

aConstraint

Constraint to be copied.

Reimplemented in OpenSim::CoordinateCouplerConstraint, OpenSim::PointConstraint, OpenSim::PointOnLineConstraint, OpenSim::RollingOnSurfaceConstraint, OpenSim::UnilateralConstraint, and OpenSim::WeldConstraint.

virtual int OpenSim::Constraint::getNumStateVariables ( ) const [inline, protected, virtual]

Gets the number of "Continuous" state variables maintained by the ModelComponent If the ModelComponent defines any that are of interest to the user, names should also be given.

Implements OpenSim::ModelComponent.

Array< std::string > Constraint::getRecordLabels ( ) const [virtual]

Methods to query a Constraint forces (defaults to the Lagrange mulipliers) applied The names of the quantities (column labels) is returned by this first function getRecordLabels().

Methods to query a Constraint forces for the value actually applied during simulation The names of the quantities (column labels) is returned by this first function getRecordLabels().

Array< double > Constraint::getRecordValues ( const SimTK::State & state ) const [virtual]

Given SimTK::State object extract all the values necessary to report constraint forces (multipliers) Subclasses can override to report force, application location frame, etc.

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

used in conjunction with getRecordLabels and should return same size Array

void Constraint::initState ( SimTK::State & state ) const [protected, virtual]

This is called after a SimTK System and State have been created for the Model.

It must be implementd to set initial values of state variables.

Parameters:

state

the State to initialize

Reimplemented from OpenSim::ModelComponent.

Reimplemented in OpenSim::RollingOnSurfaceConstraint.

bool Constraint::isDisabled ( const SimTK::State & s ) const [virtual]

Get whether or not this Constraint is disabled.

Simbody multibody system instance is realized every time the isDisabled changes, BUT multiple sets to the same value have no cost.

Parameters:

isDisabled

If true the constraint is disabled; if false the constraint is enabled.

Reimplemented in OpenSim::RollingOnSurfaceConstraint.

OpenSim::Constraint::OPENSIM_DECLARE_DERIVED	(	Constraint	,
		Object
	)

Constraint & Constraint::operator= ( const Constraint & aConstraint )

Assignment operator.

Returns:: Reference to this object.

Reimplemented from OpenSim::ModelComponent.

Reimplemented in OpenSim::CoordinateCouplerConstraint, OpenSim::PointConstraint, OpenSim::PointOnLineConstraint, OpenSim::RollingOnSurfaceConstraint, OpenSim::UnilateralConstraint, and OpenSim::WeldConstraint.

virtual void OpenSim::Constraint::scale ( const ScaleSet & aScaleSet ) [inline, virtual]

Reimplemented in OpenSim::CoordinateCouplerConstraint.

virtual void OpenSim::Constraint::setContactPointForInducedAccelerations	(	const SimTK::State &	s,
		SimTK::Vec3	point
	)			`[inline, virtual]`

This method specifies the interface that a constraint must implement in order to be used by the Induced Accelerations Analysis.

Reimplemented in OpenSim::PointConstraint, OpenSim::RollingOnSurfaceConstraint, and OpenSim::WeldConstraint.

void Constraint::setDefaultsFromState ( const SimTK::State & state ) [protected, virtual]

Set all default values for this object to match those in a specified State.

It must be implemented/overriden to set any default values defined by each subclass.

Parameters:

state

the State from which to take values that should become the defaults for this object

Reimplemented from OpenSim::ModelComponent.

Reimplemented in OpenSim::RollingOnSurfaceConstraint.

bool Constraint::setDisabled	(	SimTK::State &	s,
		bool	isDisabled
	)			`[virtual]`

Set whether or not this Constraint is disabled.

Simbody multibody system instance is realized every time the isDisabled changes, BUT multiple sets to the same value have no cost.

Parameters:

isDisabled

If true the constraint is disabled; if false the constraint is enabled.

Reimplemented in OpenSim::RollingOnSurfaceConstraint.

void Constraint::setup ( Model & aModel ) [protected, virtual]

Perform some set up functions that happen after the object has been deserialized or copied.

Parameters:

aModel

OpenSim model containing this Constraint.

Reimplemented from OpenSim::ModelComponent.

Reimplemented in OpenSim::CoordinateCouplerConstraint, OpenSim::PointConstraint, OpenSim::PointOnLineConstraint, OpenSim::RollingOnSurfaceConstraint, OpenSim::UnilateralConstraint, and OpenSim::WeldConstraint.

void Constraint::updateFromConstraint	(	SimTK::State &	s,
		const Constraint &	aConstraint
	)			`[virtual]`

Update an existing Constraint with parameter values from a new one, but only for the parameters that were explicitly specified in the XML node.

Parameters:

aConstraint

Constraint to update from

Friends And Related Function Documentation

friend class SimbodyEngine [friend]

Reimplemented in OpenSim::CoordinateCouplerConstraint, and OpenSim::WeldConstraint.

Member Data Documentation

SimTK::ConstraintIndex OpenSim::Constraint::_index [protected]

ID for the constraint in Simbody.

PropertyBool OpenSim::Constraint::_isDisabledProp [protected]

Flag indicating whether the constraint is disabled or not.

Disabled means that the constraint is not active in subsequent dynamics realizations.

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

OpenSim/Simulation/SimbodyEngine/Constraint.h
OpenSim/Simulation/SimbodyEngine/Constraint.cpp

OpenSim::Constraint Class Reference

Public Member Functions

Protected Member Functions

Protected Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

Member Data Documentation