#include <hpp/constraints/min-manipulability.hh>

Inheritance diagram for hpp::constraints::MinManipulability:

Collaboration diagram for hpp::constraints::MinManipulability:

Public Member Functions
virtual	~MinManipulability ()

void	lockJoint (const JointPtr_t &joint)

const DevicePtr_t &	robot () const
	Get robot.

Public Member Functions inherited from hpp::constraints::DifferentiableFunction
virtual	~DifferentiableFunction ()

LiegroupElement	operator() (vectorIn_t argument) const

void	value (LiegroupElementRef result, vectorIn_t argument) const

void	jacobian (matrixOut_t jacobian, vectorIn_t argument) const

const ArrayXb &	activeParameters () const

const ArrayXb &	activeDerivativeParameters () const

size_type	inputSize () const
	Get dimension of input vector.

size_type	inputDerivativeSize () const

LiegroupSpacePtr_t	outputSpace () const
	Get output space.

size_type	outputSize () const
	Get dimension of output vector.

size_type	outputDerivativeSize () const
	Get dimension of output derivative vector.

const std::string &	name () const
	Get function name.

virtual std::ostream &	print (std::ostream &o) const
	Display object in a stream.

std::string	context () const

void	context (const std::string &c)

void	finiteDifferenceForward (matrixOut_t jacobian, vectorIn_t arg, DevicePtr_t robot=DevicePtr_t(), value_type eps=std::sqrt(Eigen::NumTraits< value_type >::epsilon())) const

void	finiteDifferenceCentral (matrixOut_t jacobian, vectorIn_t arg, DevicePtr_t robot=DevicePtr_t(), value_type eps=std::sqrt(Eigen::NumTraits< value_type >::epsilon())) const

bool	operator== (DifferentiableFunction const &other) const

bool	operator!= (DifferentiableFunction const &b) const

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

Static Public Member Functions
static MinManipulabilityPtr_t	create (DifferentiableFunctionPtr_t function, DevicePtr_t robot, std::string name)

Static Public Member Functions inherited from hpp::constraints::DifferentiableFunction
static DifferentiableFunctionPtr_t	extract (DifferentiableFunctionPtr_t original, interval_t interval)

Protected Member Functions
	MinManipulability (DifferentiableFunctionPtr_t function, DevicePtr_t robot, std::string name)
	Concrete class constructor should call this constructor.

void	impl_compute (LiegroupElementRef result, vectorIn_t argument) const
	User implementation of function evaluation.

void	impl_jacobian (matrixOut_t jacobian, vectorIn_t arg) const

bool	isEqual (const DifferentiableFunction &other) const

Protected Member Functions inherited from hpp::constraints::DifferentiableFunction
	DifferentiableFunction (size_type sizeInput, size_type sizeInputDerivative, size_type sizeOutput, std::string name=std::string())
	Concrete class constructor should call this constructor.

	DifferentiableFunction (size_type sizeInput, size_type sizeInputDerivative, const LiegroupSpacePtr_t &outputSpace, std::string name=std::string())
	Concrete class constructor should call this constructor.

	DifferentiableFunction ()

Additional Inherited Members
Protected Attributes inherited from hpp::constraints::DifferentiableFunction
size_type	inputSize_
	Dimension of input vector.

size_type	inputDerivativeSize_
	Dimension of input derivative.

LiegroupSpacePtr_t	outputSpace_
	Dimension of output vector.

ArrayXb	activeParameters_

ArrayXb	activeDerivativeParameters_

Detailed Description

Enforce minimal manipulability

This function takes as input another differentiable function $f_1$ defined over the same configuration space and computes a one dimensional value as follows:

$f(\mathbf{q}) = \max \left(-\log\det(J_1 J_1^T), 0\right)$

where $J_1$ is the Jacobian matrix of $f_1$ .

As a consequence when,

$\det(J_1 J_1^T) \geq 1$ , the function is uniformly equal to 0,
$\det(J_1 J_1^T) < 1$ , the function is positive.

Inserting a constraint with this function with comparison type EQUAL_TO_ZERO into a numerical solver will make the solution lie in the domain defined by $\det(J_1 J_1^T) \geq 1$ , where the Jacobian of $f_1$ has a manipulability index (product of singular values) greater than 1.

Lock joints

In some cases, it is useful not to consider some joints in the kinematic chain. For example, when evaluating the manipulability of a robotic arm moving on a prismatic rail, it can be useful to consider the manipulability of the system when the rail is locked. To do so, call method MinManipulability::lockJoint.

Note: The Jacobian of this function is computed by finite difference.

Constructor & Destructor Documentation

◆ ~MinManipulability()

virtual hpp::constraints::MinManipulability::~MinManipulability ( )

inlinevirtual

◆ MinManipulability()

hpp::constraints::MinManipulability::MinManipulability	(	DifferentiableFunctionPtr_t	function,
		DevicePtr_t	robot,
		std::string	name )

protected

Concrete class constructor should call this constructor.

Parameters

function	the function which must be analysed
name	function's name

Member Function Documentation

◆ create()

static MinManipulabilityPtr_t hpp::constraints::MinManipulability::create	(	DifferentiableFunctionPtr_t	function,
		DevicePtr_t	robot,
		std::string	name )

inlinestatic

◆ impl_compute()

void hpp::constraints::MinManipulability::impl_compute	(	LiegroupElementRef	result,
		vectorIn_t	argument ) const

protectedvirtual

User implementation of function evaluation.

Implements hpp::constraints::DifferentiableFunction.

◆ impl_jacobian()

void hpp::constraints::MinManipulability::impl_jacobian	(	matrixOut_t	jacobian,
		vectorIn_t	arg ) const

protectedvirtual

Implements hpp::constraints::DifferentiableFunction.

◆ isEqual()

bool hpp::constraints::MinManipulability::isEqual ( const DifferentiableFunction & other ) const

inlineprotectedvirtual

Reimplemented from hpp::constraints::DifferentiableFunction.

◆ lockJoint()

void hpp::constraints::MinManipulability::lockJoint ( const JointPtr_t & joint )

Lock a joint

Consider this joint as fixed when computing the manipulability

◆ robot()

const DevicePtr_t & hpp::constraints::MinManipulability::robot ( ) const

inline

Get robot.

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

include/hpp/constraints/min-manipulability.hh

Public Member Functions

Static Public Member Functions

Protected Member Functions

Additional Inherited Members