Polyhedral wrench friction (coulomb) cone constraint according to https://scaron.info/robotics/wrench-friction-cones.html (Wrench friction cone for surface contacts). More...

#include <ContactsFrictionSurfaceConstraint.hpp>

Inheritance diagram for wbc::ContactsFrictionSurfaceConstraint:

Public Member Functions
	ContactsFrictionSurfaceConstraint (bool _reduced=false, bool _use_slack=false)
	Default constructor.
virtual	~ContactsFrictionSurfaceConstraint ()=default
virtual void	update (RobotModelPtr robot_model) override
	Update constraint matrix and vectors, depending on the type. Abstract method.
void	setUseSlack (bool enable)
	Enable/disable softening of the friction cone using one slack variable per contact.
bool	useSlack () const
	Return whether the friction cone is softened using slack variables.
Public Member Functions inherited from wbc::Constraint
virtual	~Constraint ()=default
Type	type ()
	Return the type of this constraint.
const Eigen::MatrixXd &	A ()
	return constraint matrix A
const Eigen::VectorXd &	b ()
	return constraint vector b
const Eigen::VectorXd &	lb ()
	return constraint lower bound lb
const Eigen::VectorXd &	ub ()
	return constraint upper bound ub
uint	size ()
	return size of the constraint (i.e. number of rows of the constraint matrix)

Additional Inherited Members
Public Types inherited from wbc::Constraint
enum	Type { equality = 0 , inequality = 1 , bounds = 2 }
Protected Member Functions inherited from wbc::Constraint
	Constraint ()
	Default constructor.
	Constraint (Type type)
	Constructor. Initialiye the type of this constraint.
Protected Attributes inherited from wbc::Constraint
Type	c_type
Eigen::MatrixXd	A_mtx
Eigen::VectorXd	b_vec
Eigen::VectorXd	lb_vec
Eigen::VectorXd	ub_vec

Detailed Description

Polyhedral wrench friction (coulomb) cone constraint according to https://scaron.info/robotics/wrench-friction-cones.html (Wrench friction cone for surface contacts).

If use_slack is set, the cone is softened using a single slack variable s per contact: A*f <= s, s >= 0. The slack variables are assumed to be appended to the qp variables, i.e., the variable order becomes (qdd,f_ext,s). The bounds s >= 0 and the penalty on s have to be added by the scene.

Constructor & Destructor Documentation

◆ ContactsFrictionSurfaceConstraint()

wbc::ContactsFrictionSurfaceConstraint::ContactsFrictionSurfaceConstraint	(	bool	_reduced = false,
		bool	_use_slack = false )

inlineexplicit

Default constructor.

◆ ~ContactsFrictionSurfaceConstraint()

virtual wbc::ContactsFrictionSurfaceConstraint::~ContactsFrictionSurfaceConstraint ( )

virtualdefault

Member Function Documentation

◆ setUseSlack()

void wbc::ContactsFrictionSurfaceConstraint::setUseSlack ( bool enable )

inline

Enable/disable softening of the friction cone using one slack variable per contact.

◆ update()

void wbc::ContactsFrictionSurfaceConstraint::update ( RobotModelPtr robot_model )

overridevirtual

Update constraint matrix and vectors, depending on the type. Abstract method.

Implements wbc::Constraint.

◆ useSlack()

bool wbc::ContactsFrictionSurfaceConstraint::useSlack ( ) const

inline

Return whether the friction cone is softened using slack variables.

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

src/constraints/ContactsFrictionSurfaceConstraint.hpp
src/constraints/ContactsFrictionSurfaceConstraint.cpp

Public Member Functions

Additional Inherited Members