dart::constraint::BallJointConstraint Class Reference

BallJointConstraint represents ball joint constraint between a body and the world or between two bodies. More...

#include <BallJointConstraint.hpp>

Inheritance diagram for dart::constraint::BallJointConstraint:

Public Member Functions
	BallJointConstraint (dynamics::BodyNode *_body, const Eigen::Vector3d &_jointPos)
	Constructor that takes one body and the joint position in the world frame.
	BallJointConstraint (dynamics::BodyNode *_body1, dynamics::BodyNode *_body2, const Eigen::Vector3d &_jointPos)
	Constructor that takes two bodies and the joint position in the frame of _body1.
virtual	~BallJointConstraint ()
	Destructor.
const std::string &	getType () const override
	Returns a string representing the constraint type.
dynamics::BodyNode *	getBodyNode1 () const
	Get the first BodyNode that this constraint is associated with.
dynamics::BodyNode *	getBodyNode2 () const
	Get the second BodyNode that this constraint is associated with.
std::size_t	getDimension () const
	Return dimesion of this constranit.

Static Public Member Functions
static const std::string &	getStaticType ()
	Returns constraint type for this class.
static void	setErrorAllowance (double allowance)
	Set global error reduction parameter.
static double	getErrorAllowance ()
	Get global error reduction parameter.
static void	setErrorReductionParameter (double erp)
	Set global error reduction parameter.
static double	getErrorReductionParameter ()
	Get global error reduction parameter.
static void	setMaxErrorReductionVelocity (double erv)
	Set global error reduction parameter.
static double	getMaxErrorReductionVelocity ()
	Get global error reduction parameter.
static void	setConstraintForceMixing (double cfm)
	Set global constraint force mixing parameter.
static double	getConstraintForceMixing ()
	Get global constraint force mixing parameter.
static dynamics::SkeletonPtr	getRootSkeleton (dynamics::SkeletonPtr skeleton)
static dynamics::SkeletonPtr	compressPath (dynamics::SkeletonPtr skeleton)

Protected Member Functions
void	update () override
	Update constraint using updated Skeleton's states.
void	getInformation (ConstraintInfo *_lcp) override
	Fill LCP variables.
void	applyUnitImpulse (std::size_t _index) override
	Apply unit impulse to constraint space.
void	getVelocityChange (double *_vel, bool _withCfm) override
	Get velocity change due to the uint impulse.
void	excite () override
	Excite the constraint.
void	unexcite () override
	Unexcite the constraint.
void	applyImpulse (double *_lambda) override
	Apply computed constraint impulse to constrained skeletons.
bool	isActive () const override
	Return true if this constraint is active.
dynamics::SkeletonPtr	getRootSkeleton () const override
void	uniteSkeletons () override

Protected Attributes
dynamics::BodyNode *	mBodyNode1
	First body node.
dynamics::BodyNode *	mBodyNode2
	Second body node.
std::size_t	mDim
	Dimension of constraint.

Static Protected Attributes
static double	mErrorAllowance = 0.0
	Global constraint error allowance.
static double	mErrorReductionParameter = 0.01
	Global constraint error redection parameter in the range of [0, 1].
static double	mMaxErrorReductionVelocity = 1e+1
	Maximum error reduction velocity.
static double	mConstraintForceMixing = 1e-9
	Global constraint force mixing parameter in the range of [1e-9, 1].

Private Attributes
Eigen::Vector3d	mOffset1
	Offset from the origin of body frame 1 to the ball joint position where the offset is expressed in body frame 1.
Eigen::Vector3d	mOffset2
	Offset from the origin of body frame 2 to the ball joint position where the offset is expressed in body frame 2.
Eigen::Vector3d	mViolation
	Position constraint violation expressed in body frame 1.
Eigen::Matrix< double, 3, 6 >	mJacobian1
	Linear map between constraint space and Cartesian space for body1.
Eigen::Matrix< double, 3, 6 >	mJacobian2
	Linear map between constraint space and Cartesian space for body2.
double	mOldX [3]
std::size_t	mAppliedImpulseIndex
	Index of applied impulse.

Detailed Description

BallJointConstraint represents ball joint constraint between a body and the world or between two bodies.

Constructor & Destructor Documentation

BallJointConstraint() [1/2]

dart::constraint::BallJointConstraint::BallJointConstraint	(	dynamics::BodyNode *	_body,
		const Eigen::Vector3d &	_jointPos
	)

Constructor that takes one body and the joint position in the world frame.

Parameters

[in]	_body
[in]	_jointPos	Joint position expressed in world frame

BallJointConstraint() [2/2]

dart::constraint::BallJointConstraint::BallJointConstraint	(	dynamics::BodyNode *	_body1,
		dynamics::BodyNode *	_body2,
		const Eigen::Vector3d &	_jointPos
	)

Constructor that takes two bodies and the joint position in the frame of _body1.

Parameters

[in]	_body1
[in]	_body2
[in]	_jointPos	Joint position expressed in world frame

~BallJointConstraint()

dart::constraint::BallJointConstraint::~BallJointConstraint ( )

virtual

Destructor.

Member Function Documentation

applyImpulse()

void dart::constraint::BallJointConstraint::applyImpulse ( double *  lambda )

overrideprotectedvirtual

Apply computed constraint impulse to constrained skeletons.

Implements dart::constraint::ConstraintBase.

applyUnitImpulse()

void dart::constraint::BallJointConstraint::applyUnitImpulse ( std::size_t  index )

overrideprotectedvirtual

Apply unit impulse to constraint space.

Implements dart::constraint::ConstraintBase.

compressPath()

dynamics::SkeletonPtr dart::constraint::ConstraintBase::compressPath ( dynamics::SkeletonPtr  skeleton )

staticinherited

excite()

void dart::constraint::BallJointConstraint::excite ( )

overrideprotectedvirtual

Excite the constraint.

Implements dart::constraint::ConstraintBase.

getBodyNode1()

dynamics::BodyNode * dart::constraint::DynamicJointConstraint::getBodyNode1 ( ) const

inherited

Get the first BodyNode that this constraint is associated with.

getBodyNode2()

dynamics::BodyNode * dart::constraint::DynamicJointConstraint::getBodyNode2 ( ) const

inherited

Get the second BodyNode that this constraint is associated with.

getConstraintForceMixing()

double dart::constraint::DynamicJointConstraint::getConstraintForceMixing ( )

staticinherited

Get global constraint force mixing parameter.

getDimension()

std::size_t dart::constraint::ConstraintBase::getDimension ( ) const

inherited

Return dimesion of this constranit.

getErrorAllowance()

double dart::constraint::DynamicJointConstraint::getErrorAllowance ( )

staticinherited

Get global error reduction parameter.

getErrorReductionParameter()

double dart::constraint::DynamicJointConstraint::getErrorReductionParameter ( )

staticinherited

Get global error reduction parameter.

getInformation()

void dart::constraint::BallJointConstraint::getInformation ( ConstraintInfo *  info )

overrideprotectedvirtual

Fill LCP variables.

Implements dart::constraint::ConstraintBase.

getMaxErrorReductionVelocity()

double dart::constraint::DynamicJointConstraint::getMaxErrorReductionVelocity ( )

staticinherited

Get global error reduction parameter.

getRootSkeleton() [1/2]

dynamics::SkeletonPtr dart::constraint::BallJointConstraint::getRootSkeleton ( ) const

overrideprotectedvirtual

Implements dart::constraint::ConstraintBase.

getRootSkeleton() [2/2]

dynamics::SkeletonPtr dart::constraint::ConstraintBase::getRootSkeleton ( dynamics::SkeletonPtr  skeleton )

staticinherited

getStaticType()

const std::string & dart::constraint::BallJointConstraint::getStaticType ( )

static

Returns constraint type for this class.

getType()

const std::string & dart::constraint::BallJointConstraint::getType ( ) const

overridevirtual

Returns a string representing the constraint type.

Reimplemented from dart::constraint::ConstraintBase.

getVelocityChange()

void dart::constraint::BallJointConstraint::getVelocityChange ( double *  vel, bool  withCfm  )

overrideprotectedvirtual

Get velocity change due to the uint impulse.

Implements dart::constraint::ConstraintBase.

isActive()

bool dart::constraint::BallJointConstraint::isActive ( ) const

overrideprotectedvirtual

Return true if this constraint is active.

Implements dart::constraint::ConstraintBase.

setConstraintForceMixing()

void dart::constraint::DynamicJointConstraint::setConstraintForceMixing ( double  cfm )

staticinherited

Set global constraint force mixing parameter.

setErrorAllowance()

void dart::constraint::DynamicJointConstraint::setErrorAllowance ( double  allowance )

staticinherited

Set global error reduction parameter.

setErrorReductionParameter()

void dart::constraint::DynamicJointConstraint::setErrorReductionParameter ( double  erp )

staticinherited

Set global error reduction parameter.

setMaxErrorReductionVelocity()

void dart::constraint::DynamicJointConstraint::setMaxErrorReductionVelocity ( double  erv )

staticinherited

Set global error reduction parameter.

unexcite()

void dart::constraint::BallJointConstraint::unexcite ( )

overrideprotectedvirtual

Unexcite the constraint.

Implements dart::constraint::ConstraintBase.

uniteSkeletons()

void dart::constraint::BallJointConstraint::uniteSkeletons ( )

overrideprotectedvirtual

Reimplemented from dart::constraint::ConstraintBase.

update()

void dart::constraint::BallJointConstraint::update ( )

overrideprotectedvirtual

Update constraint using updated Skeleton's states.

Implements dart::constraint::ConstraintBase.

Member Data Documentation

mAppliedImpulseIndex

std::size_t dart::constraint::BallJointConstraint::mAppliedImpulseIndex

private

Index of applied impulse.

mBodyNode1

dynamics::BodyNode* dart::constraint::DynamicJointConstraint::mBodyNode1

protectedinherited

First body node.

mBodyNode2

dynamics::BodyNode* dart::constraint::DynamicJointConstraint::mBodyNode2

protectedinherited

Second body node.

mConstraintForceMixing

double dart::constraint::DynamicJointConstraint::mConstraintForceMixing = 1e-9

staticprotectedinherited

Global constraint force mixing parameter in the range of [1e-9, 1].

The default is 1e-5

See also

http://www.ode.org/ode-latest-userguide.html#sec_3_8_0

mDim

std::size_t dart::constraint::ConstraintBase::mDim

protectedinherited

Dimension of constraint.

mErrorAllowance

double dart::constraint::DynamicJointConstraint::mErrorAllowance = 0.0

staticprotectedinherited

Global constraint error allowance.

mErrorReductionParameter

double dart::constraint::DynamicJointConstraint::mErrorReductionParameter = 0.01

staticprotectedinherited

Global constraint error redection parameter in the range of [0, 1].

The default is 0.01.

mJacobian1

Eigen::Matrix<double, 3, 6> dart::constraint::BallJointConstraint::mJacobian1

private

Linear map between constraint space and Cartesian space for body1.

mJacobian2

Eigen::Matrix<double, 3, 6> dart::constraint::BallJointConstraint::mJacobian2

private

Linear map between constraint space and Cartesian space for body2.

mMaxErrorReductionVelocity

double dart::constraint::DynamicJointConstraint::mMaxErrorReductionVelocity = 1e+1

staticprotectedinherited

Maximum error reduction velocity.

mOffset1

Eigen::Vector3d dart::constraint::BallJointConstraint::mOffset1

private

Offset from the origin of body frame 1 to the ball joint position where the offset is expressed in body frame 1.

mOffset2

Eigen::Vector3d dart::constraint::BallJointConstraint::mOffset2

private

Offset from the origin of body frame 2 to the ball joint position where the offset is expressed in body frame 2.

mOldX

double dart::constraint::BallJointConstraint::mOldX[3]

private

mViolation

Eigen::Vector3d dart::constraint::BallJointConstraint::mViolation

private

Position constraint violation expressed in body frame 1.