The H-signature in three dimensions (here: x-y-t) defines an equivalence relation based on homology using theorems from electro magnetism. More...

#include <h_signature.h>

Inheritance diagram for teb_local_planner::HSignature3d:

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Public Member Functions
template<typename BidirIter , typename Fun >
void	calculateHSignature (BidirIter path_start, BidirIter path_end, Fun fun_cplx_point, const ObstContainer *obstacles, boost::optional< TimeDiffSequence::iterator > timediff_start, boost::optional< TimeDiffSequence::iterator > timediff_end)
	Calculate the H-Signature of a path. More...

	HSignature3d (const TebConfig &cfg)
	Constructor accepting a TebConfig. More...

virtual bool	isEqual (const EquivalenceClass &other) const
	Check if two candidate classes are equivalent. More...

virtual bool	isReasonable () const
	Check if the trajectory is non-looping around any obstacle. Values greater than 1 indicate a looping trajectory. More...

virtual bool	isValid () const
	Check if the equivalence value is detected correctly. More...

const std::vector< double > &	values () const
	Get the current h-signature (read-only) More...

Public Member Functions inherited from teb_local_planner::EquivalenceClass
	EquivalenceClass ()
	Default constructor. More...

virtual	~EquivalenceClass ()
	virtual destructor More...

Private Attributes
const TebConfig *	cfg_

std::vector< double >	hsignature3d_

Detailed Description

The H-signature in three dimensions (here: x-y-t) defines an equivalence relation based on homology using theorems from electro magnetism.

The H-Signature depends on the obstacle configuration and can be utilized to check whether two trajectores belong to the same homology class. Refer to:

S. Bhattacharya et al.: Identification and Representation of Homotopy Classes of Trajectories for Search-based Path Planning in 3D, 2011

Definition at line 254 of file h_signature.h.

Constructor & Destructor Documentation

teb_local_planner::HSignature3d::HSignature3d ( const TebConfig & cfg )

inline

Constructor accepting a TebConfig.

Parameters

cfg	TebConfig storing some user configuration options

Definition at line 261 of file h_signature.h.

Member Function Documentation

template<typename BidirIter , typename Fun >

void teb_local_planner::HSignature3d::calculateHSignature	(	BidirIter	path_start,
		BidirIter	path_end,
		Fun	fun_cplx_point,
		const ObstContainer *	obstacles,
		boost::optional< TimeDiffSequence::iterator >	timediff_start,
		boost::optional< TimeDiffSequence::iterator >	timediff_end
	)

inline

Calculate the H-Signature of a path.

The implemented function accepts generic path descriptions that are restricted to the following structure:
The path is composed of points T and is represented by a std::vector< T > or similar type (std::list, std::deque, ...).
Provide a unary function with the following signature std::complex< long double > (const T& point_type) that returns a complex value for the position (Re(*)=x, Im(*)=y).

T could also be a pointer type, if the passed function also accepts a const T* point_Type.

Parameters

path_start	Iterator to the first element in the path
path_end	Iterator to the last element in the path
obstacles	obstacle container
fun_cplx_point	function accepting the dereference iterator type and that returns the position as complex number.

Template Parameters

BidirIter	Bidirectional iterator type
Fun	function of the form std::complex< long double > (const T& point_type)

Definition at line 282 of file h_signature.h.

virtual bool teb_local_planner::HSignature3d::isEqual ( const EquivalenceClass & other ) const

inlinevirtual

Check if two candidate classes are equivalent.

If the absolute value of the H-Signature is equal or greater than 1, a loop (in x-y) around the obstacle is indicated. Positive H-Signature: Obstacle lies on the left hand side of the planned trajectory Negative H-Signature: Obstacle lies on the right hand side of the planned trajectory H-Signature equals zero: Obstacle lies in infinity, has no influence on trajectory

Parameters

other The other equivalence class to test with

Implements teb_local_planner::EquivalenceClass.

Definition at line 358 of file h_signature.h.

virtual bool teb_local_planner::HSignature3d::isReasonable ( ) const

inlinevirtual

Check if the trajectory is non-looping around any obstacle. Values greater than 1 indicate a looping trajectory.

Returns: Returns false, if the trajectory loops around an obstacle

Implements teb_local_planner::EquivalenceClass.

Definition at line 402 of file h_signature.h.

virtual bool teb_local_planner::HSignature3d::isValid ( ) const

inlinevirtual

Check if the equivalence value is detected correctly.

Returns: Returns false, if the equivalence class detection failed, e.g. if nan- or inf values occur.

Implements teb_local_planner::EquivalenceClass.

Definition at line 388 of file h_signature.h.

const std::vector<double>& teb_local_planner::HSignature3d::values ( ) const

inline

Get the current h-signature (read-only)

Returns: h-signature in complex-number format

Definition at line 416 of file h_signature.h.

Member Data Documentation

const TebConfig* teb_local_planner::HSignature3d::cfg_

private

Definition at line 419 of file h_signature.h.

std::vector<double> teb_local_planner::HSignature3d::hsignature3d_

private

Definition at line 420 of file h_signature.h.

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

h_signature.h

Public Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation