GradientMethod is a base class for different ways of computing the gradient of an InverseKinematics module. More...

#include <InverseKinematics.hpp>

Inheritance diagram for dart::dynamics::InverseKinematics::GradientMethod:

Classes
struct	Properties

Public Member Functions
	GradientMethod (InverseKinematics *_ik, const std::string &_methodName, const Properties &_properties)
	Constructor. More...

virtual	~GradientMethod ()=default
	Virtual destructor. More...

virtual std::unique_ptr< GradientMethod >	clone (InverseKinematics *_newIK) const =0
	Enable this GradientMethod to be cloned to a new IK module. More...

virtual void	computeGradient (const Eigen::Vector6d &_error, Eigen::VectorXd &_grad)=0
	Override this function with your implementation of the gradient computation. More...

void	evalGradient (const Eigen::VectorXd &_q, Eigen::Map< Eigen::VectorXd > _grad)
	This function is used to handle caching the gradient vector and interfacing with the solver. More...

const std::string &	getMethodName () const
	Get the name of this GradientMethod. More...

void	clampGradient (Eigen::VectorXd &_grad) const
	Clamp the gradient based on the clamp settings of this GradientMethod. More...

void	setComponentWiseClamp (double _clamp=DefaultIKGradientComponentClamp)
	Set the component-wise clamp for this GradientMethod. More...

double	getComponentWiseClamp () const
	Get the component-wise clamp for this GradientMethod. More...

void	applyWeights (Eigen::VectorXd &_grad) const
	Apply weights to the gradient based on the weight settings of this GradientMethod. More...

void	setComponentWeights (const Eigen::VectorXd &_weights)
	Set the weights that will be applied to each component of the gradient. More...

const Eigen::VectorXd &	getComponentWeights () const
	Get the weights of this GradientMethod. More...

void	convertJacobianMethodOutputToGradient (Eigen::VectorXd &grad, const std::vector< std::size_t > &dofs)
	Convert the gradient that gets generated by Jacobian methods into a gradient that can be used by a GradientDescentSolver. More...

Properties	getGradientMethodProperties () const
	Get the Properties of this GradientMethod. More...

void	clearCache ()
	Clear the cache to force the gradient to be recomputed. More...

InverseKinematics *	getIK ()
	Returns the IK module that this GradientMethod belongs to. More...

const InverseKinematics *	getIK () const
	Returns the IK module that this GradientMethod belongs to. More...

Protected Member Functions
void	sendDestructionNotification () const
	Send a destruction notification to all Observers. More...

void	addObserver (Observer *_observer) const
	Add an Observer to the list of Observers. More...

void	removeObserver (Observer *_observer) const
	Remove an Observer from the list of Observers. More...

Protected Attributes
common::sub_ptr< InverseKinematics >	mIK
	The IK module that this GradientMethod belongs to. More...

std::string	mMethodName
	The name of this method. More...

Eigen::VectorXd	mLastPositions
	The last positions that was passed to this GradientMethod. More...

Eigen::VectorXd	mLastGradient
	The last gradient that was computed by this GradientMethod. More...

Properties	mGradientP
	Properties for this GradientMethod. More...

std::set< Observer * >	mObservers
	List of current Observers. More...

Private Attributes
Eigen::VectorXd	mInitialPositionsCache
	Cache used by convertJacobianMethodOutputToGradient to avoid reallocating this vector on each iteration. More...

Detailed Description

GradientMethod is a base class for different ways of computing the gradient of an InverseKinematics module.

Constructor & Destructor Documentation

◆ GradientMethod()

dart::dynamics::InverseKinematics::GradientMethod::GradientMethod	(	InverseKinematics *	_ik,
		const std::string &	_methodName,
		const Properties &	_properties
	)

Constructor.

◆ ~GradientMethod()

virtual dart::dynamics::InverseKinematics::GradientMethod::~GradientMethod ( )

virtualdefault

Virtual destructor.

Member Function Documentation

◆ addObserver()

void dart::common::Subject::addObserver ( Observer * _observer ) const

protectedinherited

Add an Observer to the list of Observers.

◆ applyWeights()

void dart::dynamics::InverseKinematics::GradientMethod::applyWeights ( Eigen::VectorXd & _grad ) const

Apply weights to the gradient based on the weight settings of this GradientMethod.

◆ clampGradient()

void dart::dynamics::InverseKinematics::GradientMethod::clampGradient ( Eigen::VectorXd & _grad ) const

Clamp the gradient based on the clamp settings of this GradientMethod.

◆ clearCache()

void dart::dynamics::InverseKinematics::GradientMethod::clearCache ( )

Clear the cache to force the gradient to be recomputed.

It should generally not be necessary to call this function.

◆ clone()

virtual std::unique_ptr<GradientMethod> dart::dynamics::InverseKinematics::GradientMethod::clone ( InverseKinematics * _newIK ) const

pure virtual

Enable this GradientMethod to be cloned to a new IK module.

Implemented in dart::dynamics::SharedLibraryIkFast, dart::dynamics::InverseKinematics::JacobianTranspose, and dart::dynamics::InverseKinematics::JacobianDLS.

◆ computeGradient()

virtual void dart::dynamics::InverseKinematics::GradientMethod::computeGradient	(	const Eigen::Vector6d &	_error,
		Eigen::VectorXd &	_grad
	)

pure virtual

Override this function with your implementation of the gradient computation.

The direction that this gradient points in should make the error worse if applied to the joint positions, because the Problem is configured as a gradient descent error minimization Problem.

The error vector that is passed in will be determined by the IK module's ErrorMethod. The expectation is that the first three components of the vector correspond to orientation error (in an angle-axis format) while the last three components correspond to translational error.

When implementing this function, you should assume that the Skeleton's current joint positions corresponds to the positions that you must use to compute the error. This function will only get called when an update is needed.

Implemented in dart::dynamics::InverseKinematics::Analytical, dart::dynamics::InverseKinematics::JacobianTranspose, and dart::dynamics::InverseKinematics::JacobianDLS.

◆ convertJacobianMethodOutputToGradient()

void dart::dynamics::InverseKinematics::GradientMethod::convertJacobianMethodOutputToGradient	(	Eigen::VectorXd &	grad,
		const std::vector< std::size_t > &	dofs
	)

Convert the gradient that gets generated by Jacobian methods into a gradient that can be used by a GradientDescentSolver.

Not all Joint types can be integrated using standard addition (e.g. FreeJoint and BallJoint), therefore Jacobian-based differential methods will tend to generate gradients that cannot be correctly used by a simple addition-based GradientDescentSolver. Running your gradient through this function before returning it will make the gradient suitable for a standard solver.

◆ evalGradient()

void dart::dynamics::InverseKinematics::GradientMethod::evalGradient	(	const Eigen::VectorXd &	_q,
		Eigen::Map< Eigen::VectorXd >	_grad
	)

This function is used to handle caching the gradient vector and interfacing with the solver.

◆ getComponentWeights()

const Eigen::VectorXd & dart::dynamics::InverseKinematics::GradientMethod::getComponentWeights ( ) const

Get the weights of this GradientMethod.

◆ getComponentWiseClamp()

double dart::dynamics::InverseKinematics::GradientMethod::getComponentWiseClamp ( ) const

Get the component-wise clamp for this GradientMethod.

◆ getGradientMethodProperties()

InverseKinematics::GradientMethod::Properties dart::dynamics::InverseKinematics::GradientMethod::getGradientMethodProperties ( ) const

Get the Properties of this GradientMethod.

◆ getIK() [1/2]

InverseKinematics * dart::dynamics::InverseKinematics::GradientMethod::getIK ( )

Returns the IK module that this GradientMethod belongs to.

◆ getIK() [2/2]

const InverseKinematics * dart::dynamics::InverseKinematics::GradientMethod::getIK ( ) const

Returns the IK module that this GradientMethod belongs to.

◆ getMethodName()

const std::string & dart::dynamics::InverseKinematics::GradientMethod::getMethodName ( ) const

Get the name of this GradientMethod.

◆ removeObserver()

void dart::common::Subject::removeObserver ( Observer * _observer ) const

protectedinherited

Remove an Observer from the list of Observers.

◆ sendDestructionNotification()

void dart::common::Subject::sendDestructionNotification ( ) const

protectedinherited

Send a destruction notification to all Observers.

This will cause all Observers to behave as if this Subject has been permanently deleted, so it should only be called when that behavior is desired.

◆ setComponentWeights()

void dart::dynamics::InverseKinematics::GradientMethod::setComponentWeights ( const Eigen::VectorXd & _weights )

Set the weights that will be applied to each component of the gradient.

If the number of components in _weights is smaller than the number of components in the gradient, then a weight of 1.0 will be applied to all components that are out of the range of _weights. Passing in an empty vector for _weights will effectively make all the gradient components unweighted.

◆ setComponentWiseClamp()

void dart::dynamics::InverseKinematics::GradientMethod::setComponentWiseClamp ( double _clamp = DefaultIKGradientComponentClamp )

Set the component-wise clamp for this GradientMethod.

Each component of the gradient will be individually clamped to this size.

Member Data Documentation

◆ mGradientP

Properties dart::dynamics::InverseKinematics::GradientMethod::mGradientP

protected

Properties for this GradientMethod.

◆ mIK

common::sub_ptr<InverseKinematics> dart::dynamics::InverseKinematics::GradientMethod::mIK

protected

The IK module that this GradientMethod belongs to.

◆ mInitialPositionsCache

Eigen::VectorXd dart::dynamics::InverseKinematics::GradientMethod::mInitialPositionsCache

private

Cache used by convertJacobianMethodOutputToGradient to avoid reallocating this vector on each iteration.

◆ mLastGradient

Eigen::VectorXd dart::dynamics::InverseKinematics::GradientMethod::mLastGradient

protected

The last gradient that was computed by this GradientMethod.

◆ mLastPositions

Eigen::VectorXd dart::dynamics::InverseKinematics::GradientMethod::mLastPositions

protected

The last positions that was passed to this GradientMethod.

◆ mMethodName

std::string dart::dynamics::InverseKinematics::GradientMethod::mMethodName

protected

The name of this method.

◆ mObservers

std::set<Observer*> dart::common::Subject::mObservers

mutableprotectedinherited

List of current Observers.

Classes

Public Member Functions

Protected Member Functions

Protected Attributes

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ GradientMethod()

◆ ~GradientMethod()

Member Function Documentation

◆ addObserver()

◆ applyWeights()

◆ clampGradient()

◆ clearCache()

◆ clone()

◆ computeGradient()

◆ convertJacobianMethodOutputToGradient()

◆ evalGradient()

◆ getComponentWeights()

◆ getComponentWiseClamp()

◆ getGradientMethodProperties()

◆ getIK() [1/2]

◆ getIK() [2/2]

◆ getMethodName()

◆ removeObserver()

◆ sendDestructionNotification()

◆ setComponentWeights()

◆ setComponentWiseClamp()

Member Data Documentation

◆ mGradientP

◆ mIK

◆ mInitialPositionsCache

◆ mLastGradient

◆ mLastPositions

◆ mMethodName

◆ mObservers