#include <hpp/constraints/implicit.hh>

Inheritance diagram for hpp::constraints::Implicit:

[legend]

Public Member Functions
bool	operator== (const Implicit &other) const
	Operator equality. More...

Implicit &	operator= (const Implicit &other)
	Operator assignation. More...

virtual ImplicitPtr_t	copy () const
	Copy object and return shared pointer to copy. More...

virtual	~Implicit ()

const ComparisonTypes_t &	comparisonType () const
	Return the ComparisonType. More...

void	comparisonType (const ComparisonTypes_t &comp)
	Set the comparison type. More...

const segments_t &	activeRows () const

bool	checkAllRowsActive () const
	Check if all rows are active (no inactive rows) More...

const Eigen::RowBlockIndices &	equalityIndices () const
	Get indices of constraint coordinates that are equality. More...

void	setInactiveRowsToZero (vectorOut_t error) const

DifferentiableFunction &	function () const
	Return a reference to function \(h\). More...

const DifferentiableFunctionPtr_t &	functionPtr () const
	Return a reference to function \(h\). More...

virtual std::pair< JointConstPtr_t, JointConstPtr_t >	doesConstrainRelPoseBetween (DeviceConstPtr_t robot) const

Right hand side
void	rightHandSideFromConfig (ConfigurationIn_t config, LiegroupElementRef rhs)

bool	checkRightHandSide (LiegroupElementConstRef rhs) const

size_type	parameterSize () const

size_type	rightHandSideSize () const

void	rightHandSideFunction (const DifferentiableFunctionPtr_t &rhsF)

const DifferentiableFunctionPtr_t &	rightHandSideFunction () const

vectorIn_t	rightHandSideAt (const value_type &s)

Static Public Member Functions
static ImplicitPtr_t	create (const DifferentiableFunctionPtr_t &func, ComparisonTypes_t comp, std::vector< bool > mask=std::vector< bool >())

static ImplicitPtr_t	createCopy (const ImplicitPtr_t &other)
	Create a copy and return shared pointer. More...

Protected Member Functions
	Implicit (const DifferentiableFunctionPtr_t &function, ComparisonTypes_t comp, std::vector< bool > mask)

	Implicit (const Implicit &other)
	Copy constructor. More...

virtual bool	isEqual (const Implicit &other, bool swapAndTest) const

void	init (const ImplicitWkPtr_t &weak)

	Implicit ()

Friends
class	ImplicitConstraintSet

Detailed Description

This class represents a parameterizable numerical constraint that compares the output of a function \(h\) to a right hand side Lie group element.

Definition

The function \(h\) takes input in a configuration space \(\mathcal{C}\) and output in a Lie group \(\mathbf{L}\),
the dimensions of \(\mathbf{L}\) and of its tangent space are respectively \((n_q,n_v)\).
The comparison is represented by a vector \(\mathbf{c}\) of dimension \(n_v\) with values in enum hpp::constraints::ComparisonType = { \(\mathbf{Equality}\), \(\mathbf{EqualToZero}\), \(\mathbf{Inferior}\), \(\mathbf{Superior}\) }.
The right hand side is Lie group element of dimension \(n_q\).

Error

A configuration \(\mathbf{q}\) is said to satisfy the constraint for a given right hand side if and only if the error \(e\) as computed below is smaller in norm than a given threshold.

Let

\[ \Delta = h (\mathbf{q}) - rhs \in \mathbf{R}^{n_v}, \]

for each component \(i\in\{0,\cdots,n_v-1\}\),

if \(c_i\) is \(\mathbf{Inferior}\), \(e_i = \max (0,\Delta_i)\),
if \(c_i\) is \(\mathbf{Superior}\), \(e_i = \min (0,\Delta_i)\),
if \(c_i\) is \(\mathbf{Equality}\), \(e_i = \Delta_i\),
if \(c_i\) is \(\mathbf{EqualToZero}\), \(e_i = \Delta_i\).

Mask

A mask is a vector of Boolean values of size \(n_v\). Values set to false means that the corresponding component of the error defined above is not taken into account to determine whether the constraint is satisfied. The active rows of the constraint may be accessed via method activeRows.

Parameterizable right hand side

Lines with \(\mathbf{Equality}\) comparator in the above definition of the error need a parameter, while lines with comparators \(\mathbf{Inferior}\), \(\mathbf{Superior}\), or \(\mathbf{EqualToZero}\) do not. As a consequence, the right hand side of the constraint is defined by a vector \(\lambda\) of parameters of size the number of \(\mathbf{Equality}\) occurences in vector \(\mathbf{c}\). The right hand side is then defined as in the following example:

\[ rhs = \exp\left(\begin{array}{c}\lambda_1 \\ 0 \\ 0 \\ \lambda_2 \\ \vdots \end{array}\right) \ \ \ \ \mathbf{c} = \left(\begin{array}{c}\mathbf{Equality} \\ \mathbf{EqualToZero} \\ \mathbf{Inferior} \\ \mathbf{Equality} \\ \vdots \end{array}\right) \]

To retrieve the size of vector \(\lambda\), call method Implicit::parameterSize (). To set and get the right hand side value, use method Implicit::rightHandSide.

Time varying right hand side

The right hand side of the constraint may depend on time, for instance if the constraint is associated to a trajectory following task. In this case, the right hand side is a function from \(\mathbf{R}\) to \(\mathbf{L}\).

Constructor & Destructor Documentation

◆ ~Implicit()

virtual hpp::constraints::Implicit::~Implicit ( )

inlinevirtual

◆ Implicit() [1/3]

hpp::constraints::Implicit::Implicit	(	const DifferentiableFunctionPtr_t &	function,
		ComparisonTypes_t	comp,
		std::vector< bool >	mask
	)

protected

Constructor

Parameters

function	the differentiable function
comp	vector of comparison \(\mathbf{c}\).
mask	mask defining which components of the error are taken into account to determine whether the constraint is satisfied. \precond sizes of comp and of mask should be equal to size of tangent space to function output space \(\mathbf{L}\).

◆ Implicit() [2/3]

hpp::constraints::Implicit::Implicit ( const Implicit & other )

protected

Copy constructor.

◆ Implicit() [3/3]

hpp::constraints::Implicit::Implicit ( )

inlineprotected

Member Function Documentation

◆ activeRows()

const segments_t& hpp::constraints::Implicit::activeRows ( ) const

inline

Return the active rows taken into account to determine whether the constraint is satisfied

◆ checkAllRowsActive()

bool hpp::constraints::Implicit::checkAllRowsActive ( ) const

inline

Check if all rows are active (no inactive rows)

◆ checkRightHandSide()

bool hpp::constraints::Implicit::checkRightHandSide ( LiegroupElementConstRef rhs ) const

Check right hand side with regard to comparison types

Parameters

rhs	right hand side,

Returns: true if right hand side is correct

This method checks that elements of the right hand side log corresponding to comparison types different from Equality are equal to 0.

◆ comparisonType() [1/2]

const ComparisonTypes_t& hpp::constraints::Implicit::comparisonType ( ) const

Return the ComparisonType.

◆ comparisonType() [2/2]

void hpp::constraints::Implicit::comparisonType ( const ComparisonTypes_t & comp )

Set the comparison type.

◆ copy()

virtual ImplicitPtr_t hpp::constraints::Implicit::copy ( ) const

virtual

Copy object and return shared pointer to copy.

Reimplemented in hpp::constraints::LockedJoint, hpp::constraints::explicit_::RelativePose, hpp::constraints::explicit_::ConvexShapeContact, and hpp::constraints::Explicit.

◆ create()

static ImplicitPtr_t hpp::constraints::Implicit::create	(	const DifferentiableFunctionPtr_t &	func,
		ComparisonTypes_t	comp,
		std::vector< bool >	mask = `std::vector< bool >()`
	)

static

Create a shared pointer to a new instance.

See also: constructors

◆ createCopy()

static ImplicitPtr_t hpp::constraints::Implicit::createCopy ( const ImplicitPtr_t & other )

static

Create a copy and return shared pointer.

◆ doesConstrainRelPoseBetween()

virtual std::pair<JointConstPtr_t, JointConstPtr_t> hpp::constraints::Implicit::doesConstrainRelPoseBetween ( DeviceConstPtr_t robot ) const

virtual

Get pair of joints whose relative pose is fully constrained

If the function value depends on the relative pose between j1 and j2 and if the relative pose between j1 and j2 is fully constrained because of Implicit constraint (relative transformation may still differ from one path to another), return these two joints.

Parameters

robot the device that this constraint is applied to

Returns: the pair of joints constrained, in order of increasing joint index, or a pair of empty shared pointers

Note: absolute pose is considered relative pose with respect to "universe". "universe" is returned as a nullpointer as the first element of the pair, if applicable.

Reimplemented in hpp::constraints::LockedJoint.

◆ equalityIndices()

const Eigen::RowBlockIndices& hpp::constraints::Implicit::equalityIndices ( ) const

inline

Get indices of constraint coordinates that are equality.

◆ function()

DifferentiableFunction& hpp::constraints::Implicit::function ( ) const

inline

Return a reference to function \(h\).

◆ functionPtr()

const DifferentiableFunctionPtr_t& hpp::constraints::Implicit::functionPtr ( ) const

inline

Return a reference to function \(h\).

◆ init()

void hpp::constraints::Implicit::init ( const ImplicitWkPtr_t & weak )

inlineprotected

◆ isEqual()

virtual bool hpp::constraints::Implicit::isEqual	(	const Implicit &	other,
		bool	swapAndTest
	)		const

protectedvirtual

Test equality with other instance

Parameters

other	object to copy
swapAndTest	whether we should also check other == this

Reimplemented in hpp::constraints::LockedJoint, and hpp::constraints::Explicit.

◆ operator=()

Implicit& hpp::constraints::Implicit::operator= ( const Implicit & other )

inline

Operator assignation.

◆ operator==()

bool hpp::constraints::Implicit::operator== ( const Implicit & other ) const

Operator equality.

◆ parameterSize()

size_type hpp::constraints::Implicit::parameterSize ( ) const

Get size of parameter defining the right hand side of the constraint

See class documentation for details.

◆ rightHandSideAt()

vectorIn_t hpp::constraints::Implicit::rightHandSideAt ( const value_type & s )

Evaluate and set right hand side at given time

Parameters

s time

◆ rightHandSideFromConfig()

void hpp::constraints::Implicit::rightHandSideFromConfig	(	ConfigurationIn_t	config,
		LiegroupElementRef	rhs
	)

Computes the right hand side from a configuration

in such a way that the configuration satisfies the numerical constraints

Parameters

config the input configuration.

Return values

rhs	right hand side as a Lie group element. \precond rhs should be initialized with the right LiegroupSpace (ie the output space of the function).

Warning: Only values of the right hand side corresponding to "equality constraints" are set. As a result, the input configuration may not satisfy the other constraints.

◆ rightHandSideFunction() [1/2]

const DifferentiableFunctionPtr_t& hpp::constraints::Implicit::rightHandSideFunction ( ) const

inline

Get time-varying right hand side

Returns: the mapping from \(\mathbf{R}\) to output space \(\mathbf{L}\) of \(h\) defining the variation along time of the right hand side.

◆ rightHandSideFunction() [2/2]

void hpp::constraints::Implicit::rightHandSideFunction ( const DifferentiableFunctionPtr_t & rhsF )

Set time-varying right hand side

Parameters

rhsF	Mapping from \(\mathbf{R}\) to output space \(\mathbf{L}\) of \(h\) defining the variation along time of the right hand side.

◆ rightHandSideSize()

size_type hpp::constraints::Implicit::rightHandSideSize ( ) const

Get size of right hand side of the constraint

This is the dimension (nq) of the output space of the function

◆ setInactiveRowsToZero()

void hpp::constraints::Implicit::setInactiveRowsToZero ( vectorOut_t error ) const

Set inactive components of error to 0

Return values

error error vector computed by substracting a right hand side to the output to the value of the function.

Friends And Related Function Documentation

◆ ImplicitConstraintSet

friend class ImplicitConstraintSet

friend

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

include/hpp/constraints/implicit.hh

Public Member Functions

Static Public Member Functions

Protected Member Functions

Friends

Detailed Description

Constructor & Destructor Documentation

◆ ~Implicit()

◆ Implicit() [1/3]

◆ Implicit() [2/3]

◆ Implicit() [3/3]

Member Function Documentation

◆ activeRows()

◆ checkAllRowsActive()

◆ checkRightHandSide()

◆ comparisonType() [1/2]

◆ comparisonType() [2/2]

◆ copy()

◆ create()

◆ createCopy()

◆ doesConstrainRelPoseBetween()

◆ equalityIndices()

◆ function()

◆ functionPtr()

◆ init()

◆ isEqual()

◆ operator=()

◆ operator==()

◆ parameterSize()

◆ rightHandSideAt()

◆ rightHandSideFromConfig()

◆ rightHandSideFunction() [1/2]

◆ rightHandSideFunction() [2/2]

◆ rightHandSideSize()

◆ setInactiveRowsToZero()

Friends And Related Function Documentation

◆ ImplicitConstraintSet