PathLengthOptimizer Class Reference

The PathLengthOptimizer implements the 3 different path length optimizers presented in [1]. More...

#include <PathLengthOptimizer.hpp>

Public Types
typedef rw::core::Ptr< PathLengthOptimizer >	Ptr
	smart pointer type to this class
typedef rw::core::Ptr< const PathLengthOptimizer >	CPtr
	smart pointer type to this const class
typedef std::list< rw::math::Q >	QList
	A list of configurations.

Public Member Functions
	PathLengthOptimizer (const rw::pathplanning::PlannerConstraint &constraint, rw::math::QMetric::CPtr metric)
	Constructor. More...
virtual	~PathLengthOptimizer ()
	Destructor.
rw::trajectory::QPath	pathPruning (const rw::trajectory::QPath &path) const
	Optimizes using path pruning. More...
rw::trajectory::QPath	shortCut (const rw::trajectory::QPath &path, size_t cnt, double time, double subDivideLength) const
	Optimizes using the shortcut technique. More...
rw::trajectory::QPath	shortCut (const rw::trajectory::QPath &path) const
	Optimizes using the shortcut technique. More...
rw::trajectory::QPath	partialShortCut (const rw::trajectory::QPath &path, size_t cnt, double time, double subDivideLength) const
	Optimizes using the partial shortcut technique. More...
rw::trajectory::QPath	partialShortCut (const rw::trajectory::QPath &path) const
	Optimizes using the partial shortcut technique. More...
rw::core::PropertyMap &	getPropertyMap ()
	Returns the propertymap. More...

Static Public Attributes
static const std::string	PROP_LOOPCOUNT
	Property key for the maximal number of loops.
static const std::string	PROP_MAXTIME
	Property key for max time.
static const std::string	PROP_SUBDIVLENGTH
	Property key for length of segment in when subdividing.

Detailed Description

The PathLengthOptimizer implements the 3 different path length optimizers presented in [1].

[1]: R. Geraerts and M.H. Overmars, Creating High-Quality Paths for Motion Planning, The International Journal of Robotics Research, Vol. 26, No. 8, 845-863 (2007)

The simplest algorithm pathPruning runs through the path an tests if nodes with index i and i+2 can be directly connected. If so it removed node i+1.

The shortCut algorithm works similary except that it takes two random indices i and j and tries to connect those. This algorithm is non-deterministic but more powerful than pathPruning.

The partialShortCut algorithm select two random node indices i and j and a random position in the configuration vector. A shortcut is then only tried between the values corresponding to the random position. This algorithm is generally more powerful than shortCut but may in some cases be more computational expensive.

Constructor & Destructor Documentation

PathLengthOptimizer()

PathLengthOptimizer	(	const rw::pathplanning::PlannerConstraint &	constraint,
		rw::math::QMetric::CPtr	metric
	)

Constructor.

Path optimization is based on a constraint for edges together with a distance metric to measure whether the path modifications decrease the length of the path.

Parameters

constraint	[in] Verification of edges and configurations.
metric	[in] Distance metric for edge lengths

Member Function Documentation

getPropertyMap()

rw::core::PropertyMap& getPropertyMap

(

)

Returns the propertymap.

Returns

Reference to the property map

partialShortCut() [1/2]

rw::trajectory::QPath partialShortCut

(

const rw::trajectory::QPath &

path

)

const

Optimizes using the partial shortcut technique.

Works similar to partialShortCut(const rw::pathplanning::Path&, size_t, double, double) except that parameters are read from the propertymap.

Parameters

path	[inout] Path to optimize

Returns

The optimized path

partialShortCut() [2/2]

rw::trajectory::QPath partialShortCut	(	const rw::trajectory::QPath &	path,
		size_t	cnt,
		double	time,
		double	subDivideLength
	)		const

Optimizes using the partial shortcut technique.

The partialShortCut algorithm select two random node indices i and j and a random position in the configuration vector. A shortcut is then only tried between the values corresponding to the random position.

The algorithm will loop until either the specified cnt is of met or the specified time is reached.

Parameters

path	[inout] Path to optimize
cnt	[in] Max count to use. If cnt=0, only the time limit will be used
time	[in] Max time to use (in seconds). If time=0, only the cnt limit will be used
subDivideLength	[in] The length into which the path is subdivided

pathPruning()

rw::trajectory::QPath pathPruning

(

const rw::trajectory::QPath &

path

)

const

Optimizes using path pruning.

pathPruning runs through the path an tests if nodes with index i and i+2 can be directly connected. If so it removes node i+1.

Parameters

path	[in] Path to optimize

shortCut() [1/2]

rw::trajectory::QPath shortCut

(

const rw::trajectory::QPath &

path

)

const

Optimizes using the shortcut technique.

Works similar to shortCut(const rw::pathplanning::Path&, size_t, double, double) except that parameters are read from the propertymap.

Parameters

path	[inout] Path to optimize

shortCut() [2/2]

rw::trajectory::QPath shortCut	(	const rw::trajectory::QPath &	path,
		size_t	cnt,
		double	time,
		double	subDivideLength
	)		const

Optimizes using the shortcut technique.

The shortCut algorithm works by selecting two random indices i and j and try to connect those.

The algorithm will loop until either the specified cnt is of met or the specified time is reached.

Parameters

path	[inout] Path to optimize
cnt	[in] Max count to use. If cnt=0, only the time limit will be used
time	[in] Max time to use (in seconds). If time=0, only the cnt limit will be used
subDivideLength	[in] The length into which the path is subdivided

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

• PathLengthOptimizer.hpp