This class encapsulates a friction cone. More...

#include <friction-cone.hpp>

Public Types
typedef MathBaseTpl< Scalar >	MathBase

typedef MathBase::Matrix3s	Matrix3s

typedef MathBase::MatrixX3s	MatrixX3s

typedef MathBase::MatrixXs	MatrixXs

typedef MathBase::Quaternions	Quaternions

typedef MathBase::Vector3s	Vector3s

typedef MathBase::VectorXs	VectorXs

Public Member Functions
	FrictionConeTpl ()
	Initialize the friction cone.

	FrictionConeTpl (const Matrix3s &R, const Scalar mu, std::size_t nf=4, const bool inner_appr=true, const Scalar min_nforce=Scalar(0.), const Scalar max_nforce=std::numeric_limits< Scalar >::infinity())
	Initialize the wrench cone.

	DEPRECATED ("Use constructor based on rotation matrix.", FrictionConeTpl(const Vector3s &normal, const Scalar mu, std::size_t nf=4, const bool inner_appr=true, const Scalar min_nforce=Scalar(0.), const Scalar max_nforce=std::numeric_limits< Scalar >::infinity());) FrictionConeTpl(const FrictionConeTpl< Scalar > &cone)
	Initialize the wrench cone.

	DEPRECATED ("Use update()", void update(const Vector3s &normal, const Scalar mu, const bool inner_appr=true, const Scalar min_nforce=Scalar(0.), const Scalar max_nforce=std::numeric_limits< Scalar >::infinity()))

const MatrixX3s &	get_A () const
	Return the matrix of friction cone.

bool	get_inner_appr () const
	Return the label that describes the type of friction cone approximation (inner/outer)

const VectorXs &	get_lb () const
	Return the lower bound of the friction cone.

const Scalar	get_max_nforce () const
	Return the maximum normal force.

const Scalar	get_min_nforce () const
	Return the minimum normal force.

const Scalar	get_mu () const
	Return the friction coefficient.

std::size_t	get_nf () const
	Return the number of facets.

const Matrix3s &	get_R () const
	Return the surface normal vector.

const VectorXs &	get_ub () const
	Return the upper bound of the friction cone.

FrictionConeTpl< Scalar > &	operator= (const FrictionConeTpl< Scalar > &other)

void	set_inner_appr (const bool inner_appr)
	Modify the label that describes the type of friction cone approximation (inner/outer)

void	set_max_nforce (const Scalar max_nforce)
	Modify the maximum normal force.

void	set_min_nforce (const Scalar min_nforce)
	Modify the maximum normal force.

void	set_mu (const Scalar mu)
	Modify friction coefficient.

void	set_R (const Matrix3s &R)
	Modify the rotation matrix that defines the cone orientation w.r.t. the inertial frame.

void	update ()
	Update the matrix and bound of friction cone inequalities in the world frame.

Public Attributes
EIGEN_MAKE_ALIGNED_OPERATOR_NEW typedef _Scalar	Scalar

Friends
template<class Scalar >
std::ostream &	operator<< (std::ostream &os, const FrictionConeTpl< Scalar > &X)

Detailed Description

template<typename _Scalar>
class crocoddyl::FrictionConeTpl< _Scalar >

This class encapsulates a friction cone.

A friction cone is a 3D cone that characterizes feasible contact wrench. The friction cone defines a linearized version (pyramid) with a predefined number of facets.

/sa WrenchConeTpl

Definition at line 28 of file friction-cone.hpp.

Member Typedef Documentation

◆ MathBase

template<typename _Scalar >

typedef MathBaseTpl<Scalar> MathBase

Definition at line 33 of file friction-cone.hpp.

◆ Vector3s

template<typename _Scalar >

typedef MathBase::Vector3s Vector3s

Definition at line 34 of file friction-cone.hpp.

◆ Matrix3s

template<typename _Scalar >

typedef MathBase::Matrix3s Matrix3s

Definition at line 35 of file friction-cone.hpp.

◆ VectorXs

template<typename _Scalar >

typedef MathBase::VectorXs VectorXs

Definition at line 36 of file friction-cone.hpp.

◆ MatrixXs

template<typename _Scalar >

typedef MathBase::MatrixXs MatrixXs

Definition at line 37 of file friction-cone.hpp.

◆ MatrixX3s

template<typename _Scalar >

typedef MathBase::MatrixX3s MatrixX3s

Definition at line 38 of file friction-cone.hpp.

◆ Quaternions

template<typename _Scalar >

typedef MathBase::Quaternions Quaternions

Definition at line 39 of file friction-cone.hpp.

Constructor & Destructor Documentation

◆ FrictionConeTpl()

template<typename _Scalar >

FrictionConeTpl	(	const Matrix3s &	R,
		const Scalar	mu,
		std::size_t	nf = `4`,
		const bool	inner_appr = `true`,
		const Scalar	min_nforce = `Scalar(0.)`,
		const Scalar	max_nforce = `std::numeric_limits< Scalar >::infinity()`
	)

Initialize the wrench cone.

Parameters

[in]	R	Rotation matrix that defines the cone orientation w.r.t. the inertial frame
[in]	mu	Friction coefficient
[in]	nf	Number of facets (default 4)
[in]	inner_appr	Label that describes the type of friction cone approximation (inner/outer)
[in]	min_nforce	Minimum normal force (default 0.)
[in]	max_nforce	Maximum normal force (default inf number))

Member Function Documentation

◆ DEPRECATED()

template<typename _Scalar >

DEPRECATED	(	"Use constructor based on rotation matrix."	,
		FrictionConeTpl< _Scalar >(const Vector3s &normal, const Scalar mu, std::size_t nf=4, const bool inner_appr=true, const Scalar min_nforce=Scalar(0.), const Scalar max_nforce=std::numeric_limits< Scalar >::infinity());
	)		const &

Initialize the wrench cone.

Parameters

[in] cone Friction cone

◆ update()

template<typename _Scalar >

void update ( )

Update the matrix and bound of friction cone inequalities in the world frame.

This matrix-vector pair describes the linearized Coulomb friction model as follow: \( -ub \leq A \times w \leq -lb \), where wrench, \( w \), is expressed in the inertial frame located with axes parallel to those of the world frame.