ompl::geometric::KPIECE1 Class Reference

Kinematic Planning by Interior-Exterior Cell Exploration. More...

#include <KPIECE1.h>

Inheritance diagram for ompl::geometric::KPIECE1:

Classes
class	Motion
	Representation of a motion for this algorithm. More...
Public Member Functions
virtual void	clear (void)
	Clear all internal datastructures. Planner settings are not affected. Subsequent calls to solve() will ignore all previous work.
double	getBadCellScoreFactor (void) const
	Get the factor that is multiplied to a cell's score if extending a motion from that cell failed.
double	getBorderFraction (void) const
	Get the fraction of time to focus exploration on boundary.
double	getGoalBias (void) const
	Get the goal bias the planner is using.
double	getGoodCellScoreFactor (void) const
	Get the factor that is multiplied to a cell's score if extending a motion from that cell succeeded.
double	getMinValidPathFraction (void) const
	Get the value of the fraction set by setMinValidPathFraction().
virtual void	getPlannerData (base::PlannerData &data) const
	Get information about the current run of the motion planner. Repeated calls to this function will update data (only additions are made). This is useful to see what changed in the exploration datastructure, between calls to solve(), for example (without calling clear() in between).
const base::ProjectionEvaluatorPtr &	getProjectionEvaluator (void) const
	Get the projection evaluator.
double	getRange (void) const
	Get the range the planner is using.
	KPIECE1 (const base::SpaceInformationPtr &si)
	Constructor.
void	setBorderFraction (double bp)
	Set the fraction of time for focusing on the border (between 0 and 1). This is the minimum fraction used to select cells that are exterior (minimum because if 95% of cells are on the border, they will be selected with 95% chance, even if this fraction is set to 90%).
void	setCellScoreFactor (double good, double bad)
	When extending a motion from a cell, the extension can be successful or it can fail. If the extension is successful, the score of the cell is multiplied by good. If the extension fails, the score of the cell is multiplied by bad. These numbers should be in the range (0, 1].
void	setGoalBias (double goalBias)
	Set the goal bias.
void	setMinValidPathFraction (double fraction)
	When extending a motion, the planner can decide to keep the first valid part of it, even if invalid states are found, as long as the valid part represents a sufficiently large fraction from the original motion. This function sets the minimum acceptable fraction (between 0 and 1).
void	setProjectionEvaluator (const std::string &name)
	Set the projection evaluator (select one from the ones registered with the state space).
void	setProjectionEvaluator (const base::ProjectionEvaluatorPtr &projectionEvaluator)
	Set the projection evaluator. This class is able to compute the projection of a given state.
void	setRange (double distance)
	Set the range the planner is supposed to use.
virtual void	setup (void)
	Perform extra configuration steps, if needed. This call will also issue a call to ompl::base::SpaceInformation::setup() if needed. This must be called before solving.
virtual bool	solve (const base::PlannerTerminationCondition &ptc)
	Function that can solve the motion planning problem. This function can be called multiple times on the same problem, without calling clear() in between. This allows the planner to continue work more time on an unsolved problem, for example. If this option is used, it is assumed the problem definition is not changed (unpredictable results otherwise). The only change in the problem definition that is accounted for is the addition of starting or goal states (but not changing previously added start/goal states). The function terminates if the call to ptc returns true.
virtual	~KPIECE1 (void)
Protected Member Functions
void	freeMotion (Motion *motion)
	Free the memory for a motion.
Protected Attributes
double	badScoreFactor_
	When extending a motion from a cell, the extension can fail. If it is, the score of the cell is multiplied by this factor.
Discretization< Motion >	disc_
	The tree datastructure and the grid that covers it.
double	goalBias_
	The fraction of time the goal is picked as the state to expand towards (if such a state is available).
double	goodScoreFactor_
	When extending a motion from a cell, the extension can be successful. If it is, the score of the cell is multiplied by this factor.
double	maxDistance_
	The maximum length of a motion to be added to a tree.
double	minValidPathFraction_
	When extending a motion, the planner can decide to keep the first valid part of it, even if invalid states are found, as long as the valid part represents a sufficiently large fraction from the original motion.
base::ProjectionEvaluatorPtr	projectionEvaluator_
	This algorithm uses a discretization (a grid) to guide the exploration. The exploration is imposed on a projection of the state space.
RNG	rng_
	The random number generator.
base::StateSamplerPtr	sampler_
	A state space sampler.

Detailed Description

Kinematic Planning by Interior-Exterior Cell Exploration.

Short description: KPIECE is a tree-based planner that uses a discretization (multiple levels, in general) to guide the exploration of the continuous space. This implementation is a simplified one, using a single level of discretization: one grid. The grid is imposed on a projection of the state space. When exploring the space, preference is given to the boundary of this grid. The boundary is computed to be the set of grid cells that have less than 2n non-diagonal neighbors in an n-dimensional projection space. It is important to set the projection the algorithm uses (setProjectionEvaluator() function). If no projection is set, the planner will attempt to use the default projection associated to the state space. An exception is thrown if no default projection is available either.

External documentation: I.A. Şucan and L.E. Kavraki, Kinodynamic motion planning by interior-exterior cell exploration, in Workshop on the Algorithmic Foundations of Robotics, Dec. 2008.
[PDF]

Definition at line 76 of file geometric/planners/kpiece/KPIECE1.h.

Constructor & Destructor Documentation

ompl::geometric::KPIECE1::KPIECE1 ( const base::SpaceInformationPtr & si ) [inline]

Constructor.

Definition at line 81 of file geometric/planners/kpiece/KPIECE1.h.

virtual ompl::geometric::KPIECE1::~KPIECE1 ( void ) [inline, virtual]

Definition at line 93 of file geometric/planners/kpiece/KPIECE1.h.

Member Function Documentation

virtual void ompl::geometric::KPIECE1::clear ( void ) [virtual]

Clear all internal datastructures. Planner settings are not affected. Subsequent calls to solve() will ignore all previous work.

Reimplemented from ompl::base::Planner.

void ompl::geometric::KPIECE1::freeMotion ( Motion * motion ) [protected]

Free the memory for a motion.

double ompl::geometric::KPIECE1::getBadCellScoreFactor ( void ) const [inline]

Get the factor that is multiplied to a cell's score if extending a motion from that cell failed.

Definition at line 193 of file geometric/planners/kpiece/KPIECE1.h.

double ompl::geometric::KPIECE1::getBorderFraction ( void ) const [inline]

Get the fraction of time to focus exploration on boundary.

Definition at line 150 of file geometric/planners/kpiece/KPIECE1.h.

double ompl::geometric::KPIECE1::getGoalBias ( void ) const [inline]

Get the goal bias the planner is using.

Definition at line 116 of file geometric/planners/kpiece/KPIECE1.h.

double ompl::geometric::KPIECE1::getGoodCellScoreFactor ( void ) const [inline]

Get the factor that is multiplied to a cell's score if extending a motion from that cell succeeded.

Definition at line 186 of file geometric/planners/kpiece/KPIECE1.h.

double ompl::geometric::KPIECE1::getMinValidPathFraction ( void ) const [inline]

Get the value of the fraction set by setMinValidPathFraction().

Definition at line 167 of file geometric/planners/kpiece/KPIECE1.h.

virtual void ompl::geometric::KPIECE1::getPlannerData ( base::PlannerData & data ) const [virtual]

Get information about the current run of the motion planner. Repeated calls to this function will update data (only additions are made). This is useful to see what changed in the exploration datastructure, between calls to solve(), for example (without calling clear() in between).

Reimplemented from ompl::base::Planner.

const base::ProjectionEvaluatorPtr& ompl::geometric::KPIECE1::getProjectionEvaluator ( void ) const [inline]

Get the projection evaluator.

Definition at line 213 of file geometric/planners/kpiece/KPIECE1.h.

double ompl::geometric::KPIECE1::getRange ( void ) const [inline]

Get the range the planner is using.

Definition at line 132 of file geometric/planners/kpiece/KPIECE1.h.

void ompl::geometric::KPIECE1::setBorderFraction ( double bp ) [inline]

Set the fraction of time for focusing on the border (between 0 and 1). This is the minimum fraction used to select cells that are exterior (minimum because if 95% of cells are on the border, they will be selected with 95% chance, even if this fraction is set to 90%).

Definition at line 143 of file geometric/planners/kpiece/KPIECE1.h.

void ompl::geometric::KPIECE1::setCellScoreFactor	(	double	good,
		double	bad
	)			`[inline]`

When extending a motion from a cell, the extension can be successful or it can fail. If the extension is successful, the score of the cell is multiplied by good. If the extension fails, the score of the cell is multiplied by bad. These numbers should be in the range (0, 1].

Definition at line 178 of file geometric/planners/kpiece/KPIECE1.h.

void ompl::geometric::KPIECE1::setGoalBias ( double goalBias ) [inline]

Set the goal bias.

In the process of randomly selecting states in the state space to attempt to go towards, the algorithm may in fact choose the actual goal state, if it knows it, with some probability. This probability is a real number between 0.0 and 1.0; its value should usually be around 0.05 and should not be too large. It is probably a good idea to use the default value.

Definition at line 110 of file geometric/planners/kpiece/KPIECE1.h.

void ompl::geometric::KPIECE1::setMinValidPathFraction ( double fraction ) [inline]

When extending a motion, the planner can decide to keep the first valid part of it, even if invalid states are found, as long as the valid part represents a sufficiently large fraction from the original motion. This function sets the minimum acceptable fraction (between 0 and 1).

Definition at line 161 of file geometric/planners/kpiece/KPIECE1.h.

void ompl::geometric::KPIECE1::setProjectionEvaluator ( const std::string & name ) [inline]

Set the projection evaluator (select one from the ones registered with the state space).

Definition at line 207 of file geometric/planners/kpiece/KPIECE1.h.

void ompl::geometric::KPIECE1::setProjectionEvaluator ( const base::ProjectionEvaluatorPtr & projectionEvaluator ) [inline]

Set the projection evaluator. This class is able to compute the projection of a given state.

Definition at line 200 of file geometric/planners/kpiece/KPIECE1.h.

void ompl::geometric::KPIECE1::setRange ( double distance ) [inline]

Set the range the planner is supposed to use.

This parameter greatly influences the runtime of the algorithm. It represents the maximum length of a motion to be added in the tree of motions.

Definition at line 126 of file geometric/planners/kpiece/KPIECE1.h.

virtual void ompl::geometric::KPIECE1::setup ( void ) [virtual]

Perform extra configuration steps, if needed. This call will also issue a call to ompl::base::SpaceInformation::setup() if needed. This must be called before solving.

Reimplemented from ompl::base::Planner.

virtual bool ompl::geometric::KPIECE1::solve ( const base::PlannerTerminationCondition & ptc ) [virtual]

Function that can solve the motion planning problem. This function can be called multiple times on the same problem, without calling clear() in between. This allows the planner to continue work more time on an unsolved problem, for example. If this option is used, it is assumed the problem definition is not changed (unpredictable results otherwise). The only change in the problem definition that is accounted for is the addition of starting or goal states (but not changing previously added start/goal states). The function terminates if the call to ptc returns true.

Implements ompl::base::Planner.

Member Data Documentation

double ompl::geometric::KPIECE1::badScoreFactor_ [protected]

When extending a motion from a cell, the extension can fail. If it is, the score of the cell is multiplied by this factor.

Definition at line 271 of file geometric/planners/kpiece/KPIECE1.h.

Discretization<Motion> ompl::geometric::KPIECE1::disc_ [protected]

The tree datastructure and the grid that covers it.

Definition at line 256 of file geometric/planners/kpiece/KPIECE1.h.

double ompl::geometric::KPIECE1::goalBias_ [protected]

The fraction of time the goal is picked as the state to expand towards (if such a state is available).

Definition at line 274 of file geometric/planners/kpiece/KPIECE1.h.

double ompl::geometric::KPIECE1::goodScoreFactor_ [protected]

When extending a motion from a cell, the extension can be successful. If it is, the score of the cell is multiplied by this factor.

Definition at line 266 of file geometric/planners/kpiece/KPIECE1.h.

double ompl::geometric::KPIECE1::maxDistance_ [protected]

The maximum length of a motion to be added to a tree.

Definition at line 284 of file geometric/planners/kpiece/KPIECE1.h.

double ompl::geometric::KPIECE1::minValidPathFraction_ [protected]

When extending a motion, the planner can decide to keep the first valid part of it, even if invalid states are found, as long as the valid part represents a sufficiently large fraction from the original motion.

Definition at line 281 of file geometric/planners/kpiece/KPIECE1.h.

base::ProjectionEvaluatorPtr ompl::geometric::KPIECE1::projectionEvaluator_ [protected]

This algorithm uses a discretization (a grid) to guide the exploration. The exploration is imposed on a projection of the state space.

Definition at line 261 of file geometric/planners/kpiece/KPIECE1.h.

RNG ompl::geometric::KPIECE1::rng_ [protected]

The random number generator.

Definition at line 287 of file geometric/planners/kpiece/KPIECE1.h.

base::StateSamplerPtr ompl::geometric::KPIECE1::sampler_ [protected]

A state space sampler.

Definition at line 253 of file geometric/planners/kpiece/KPIECE1.h.

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