ompl::geometric::LBKPIECE1 Class Reference

Lazy Bi-directional KPIECE with one level of discretization. More...

#include <ompl/geometric/planners/kpiece/LBKPIECE1.h>

Inheritance diagram for ompl::geometric::LBKPIECE1:

Classes
class	Motion
	Representation of a motion for this algorithm. More...

Public Member Functions
	LBKPIECE1 (const base::SpaceInformationPtr &si)
	Constructor.
void	setProjectionEvaluator (const base::ProjectionEvaluatorPtr &projectionEvaluator)
	Set the projection evaluator. This class is able to compute the projection of a given state.
void	setProjectionEvaluator (const std::string &name)
	Set the projection evaluator (select one from the ones registered with the state space).
const base::ProjectionEvaluatorPtr &	getProjectionEvaluator () const
	Get the projection evaluator.
void	setRange (double distance)
	Set the range the planner is supposed to use. More...
double	getRange () const
	Get the range the planner is using.
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%)
double	getBorderFraction () const
	Get the fraction of time to focus exploration on boundary.
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.
double	getMinValidPathFraction () const
	Get the value of the fraction set by setMinValidPathFraction()
void	setup () override
	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.
base::PlannerStatus	solve (const base::PlannerTerminationCondition &ptc) override
	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 for 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). If clearQuery() is called, the planner may retain prior datastructures generated from a previous query on a new problem definition. The function terminates if the call to ptc returns true.
void	clear () override
	Clear all internal datastructures. Planner settings are not affected. Subsequent calls to solve() will ignore all previous work.
void	getPlannerData (base::PlannerData &data) const override
	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).
Public Member Functions inherited from ompl::base::Planner
	Planner (const Planner &)=delete
Planner &	operator= (const Planner &)=delete
	Planner (SpaceInformationPtr si, std::string name)
	Constructor.
virtual	~Planner ()=default
	Destructor.
template<class T >
T *	as ()
	Cast this instance to a desired type. More...
template<class T >
const T *	as () const
	Cast this instance to a desired type. More...
const SpaceInformationPtr &	getSpaceInformation () const
	Get the space information this planner is using.
const ProblemDefinitionPtr &	getProblemDefinition () const
	Get the problem definition the planner is trying to solve.
ProblemDefinitionPtr &	getProblemDefinition ()
	Get the problem definition the planner is trying to solve.
const PlannerInputStates &	getPlannerInputStates () const
	Get the planner input states.
virtual void	setProblemDefinition (const ProblemDefinitionPtr &pdef)
	Set the problem definition for the planner. The problem needs to be set before calling solve(). Note: If this problem definition replaces a previous one, it may also be necessary to call clear() or clearQuery().
PlannerStatus	solve (const PlannerTerminationConditionFn &ptc, double checkInterval)
	Same as above except the termination condition is only evaluated at a specified interval.
PlannerStatus	solve (double solveTime)
	Same as above except the termination condition is solely a time limit: the number of seconds the algorithm is allowed to spend planning.
virtual void	clearQuery ()
	Clears internal datastructures of any query-specific information from the previous query. Planner settings are not affected. The planner, if able, should retain all datastructures generated from previous queries that can be used to help solve the next query. Note that clear() should also clear all query-specific information along with all other datastructures in the planner. By default clearQuery() calls clear().
const std::string &	getName () const
	Get the name of the planner.
void	setName (const std::string &name)
	Set the name of the planner.
const PlannerSpecs &	getSpecs () const
	Return the specifications (capabilities of this planner)
virtual void	checkValidity ()
	Check to see if the planner is in a working state (setup has been called, a goal was set, the input states seem to be in order). In case of error, this function throws an exception.
bool	isSetup () const
	Check if setup() was called for this planner.
ParamSet &	params ()
	Get the parameters for this planner.
const ParamSet &	params () const
	Get the parameters for this planner.
const PlannerProgressProperties &	getPlannerProgressProperties () const
	Retrieve a planner's planner progress property map.
virtual void	printProperties (std::ostream &out) const
	Print properties of the motion planner.
virtual void	printSettings (std::ostream &out) const
	Print information about the motion planner's settings.

Protected Member Functions
void	freeMotion (Motion *motion)
	Free the memory for a motion.
void	removeMotion (Discretization< Motion > &disc, Motion *motion)
	Remove a motion from a tree of motions.
bool	isPathValid (Discretization< Motion > &disc, Motion *motion, base::State *temp)
	Since solutions are computed in a lazy fashion, once trees are connected, the solution found needs to be checked for validity. This function checks whether the reverse path from a given motion to a root is valid. If this is not the case, invalid motions are removed
Protected Member Functions inherited from ompl::base::Planner
template<typename T , typename PlannerType , typename SetterType , typename GetterType >
void	declareParam (const std::string &name, const PlannerType &planner, const SetterType &setter, const GetterType &getter, const std::string &rangeSuggestion="")
	This function declares a parameter for this planner instance, and specifies the setter and getter functions.
template<typename T , typename PlannerType , typename SetterType >
void	declareParam (const std::string &name, const PlannerType &planner, const SetterType &setter, const std::string &rangeSuggestion="")
	This function declares a parameter for this planner instance, and specifies the setter function.
void	addPlannerProgressProperty (const std::string &progressPropertyName, const PlannerProgressProperty &prop)
	Add a planner progress property called progressPropertyName with a property querying function prop to this planner's progress property map.

Protected Attributes
base::StateSamplerPtr	sampler_
	The employed state sampler.
base::ProjectionEvaluatorPtr	projectionEvaluator_
	The employed projection evaluator.
Discretization< Motion >	dStart_
	The start tree.
Discretization< Motion >	dGoal_
	The goal tree.
double	minValidPathFraction_ {0.5}
	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.
double	maxDistance_ {0.}
	The maximum length of a motion to be added to a tree.
RNG	rng_
	The random number generator.
std::pair< base::State *, base::State * >	connectionPoint_ {nullptr, nullptr}
	The pair of states in each tree connected during planning. Used for PlannerData computation.
Protected Attributes inherited from ompl::base::Planner
SpaceInformationPtr	si_
	The space information for which planning is done.
ProblemDefinitionPtr	pdef_
	The user set problem definition.
PlannerInputStates	pis_
	Utility class to extract valid input states
std::string	name_
	The name of this planner.
PlannerSpecs	specs_
	The specifications of the planner (its capabilities)
ParamSet	params_
	A map from parameter names to parameter instances for this planner. This field is populated by the declareParam() function.
PlannerProgressProperties	plannerProgressProperties_
	A mapping between this planner's progress property names and the functions used for querying those progress properties.
bool	setup_
	Flag indicating whether setup() has been called.

Additional Inherited Members
Public Types inherited from ompl::base::Planner
using	PlannerProgressProperty = std::function< std::string()>
	Definition of a function which returns a property about the planner's progress that can be queried by a benchmarking routine.
using	PlannerProgressProperties = std::map< std::string, PlannerProgressProperty >
	A dictionary which maps the name of a progress property to the function to be used for querying that property.

Detailed Description

Lazy Bi-directional KPIECE with one level of discretization.

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. This variant of the implementation use two trees of exploration with lazy collision checking, hence the LB prefix.

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]
• R. Bohlin and L.E. Kavraki, Path planning using lazy PRM, in Proc. 2000 IEEE Intl. Conf. on Robotics and Automation, pp. 521–528, 2000. DOI: 10.1109/ROBOT.2000.844107
  [PDF]

Definition at line 142 of file LBKPIECE1.h.

Member Function Documentation

setRange()

void ompl::geometric::LBKPIECE1::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 207 of file LBKPIECE1.h.

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

• ompl/geometric/planners/kpiece/LBKPIECE1.h
• ompl/geometric/planners/kpiece/src/LBKPIECE1.cpp