Template Class FrictionConeTpl

Defined in File friction-cone.hpp

Class Documentation

template<typename _Scalar> class FrictionConeTpl

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

Public Types

typedef MathBaseTpl<Scalar> MathBase

typedef MathBase::Vector3s Vector3s

typedef MathBase::Matrix3s Matrix3s

typedef MathBase::VectorXs VectorXs

typedef MathBase::MatrixXs MatrixXs

typedef MathBase::MatrixX3s MatrixX3s

typedef MathBase::Quaternions Quaternions

Public Functions

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:

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

FrictionConeTpl(const FrictionConeTpl<Scalar> &cone)

Initialize the wrench cone.

Parameters:: cone – [in] Friction cone

explicit FrictionConeTpl(): Initialize the friction cone.

~FrictionConeTpl()

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.

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()))

template<typename NewScalar> FrictionConeTpl<NewScalar> cast() const

Cast the friction cone to a different scalar type.

It is useful for operations requiring different precision or scalar types.

Template Parameters:: NewScalar – The new scalar type to cast to.
Returns:: FrictionConeTpl<NewScalar> An friction conel with the new scalar type.

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

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

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

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

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

const Scalar get_mu() const: Return the friction coefficient.

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

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

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

void set_R(const Matrix3s &R)

Modify the rotation matrix that defines the cone orientation w.r.t. the inertial frame.