ompl::geometric::STRIDE Class Reference

Search Tree with Resolution Independent Density Estimation. More...

#include <ompl/geometric/planners/stride/STRIDE.h>

Inheritance diagram for ompl::geometric::STRIDE:

Classes
class	Motion
	The definition of a motion. More...

Public Member Functions
	STRIDE (const base::SpaceInformationPtr &si, bool useProjectedDistance=false, unsigned int degree=16, unsigned int minDegree=12, unsigned int maxDegree=18, unsigned int maxNumPtsPerLeaf=6, double estimatedDimension=0.0)
	Constructor.
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	setGoalBias (double goalBias)
	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.
double	getGoalBias () const
	Get the goal bias the planner is using.
void	setUseProjectedDistance (bool useProjectedDistance)
	Set whether nearest neighbors are computed based on distances in a projection of the state rather distances in the state space itself.
bool	getUseProjectedDistance () const
	Return whether nearest neighbors are computed based on distances in a projection of the state rather distances in the state space itself.
void	setDegree (unsigned int degree)
	Set desired degree of a node in the GNAT.
unsigned int	getDegree () const
	Get desired degree of a node in the GNAT.
void	setMinDegree (unsigned int minDegree)
	Set minimum degree of a node in the GNAT.
unsigned int	getMinDegree () const
	Get minimum degree of a node in the GNAT.
void	setMaxDegree (unsigned int maxDegree)
	Set maximum degree of a node in the GNAT.
unsigned int	getMaxDegree () const
	Set maximum degree of a node in the GNAT.
void	setMaxNumPtsPerLeaf (unsigned int maxNumPtsPerLeaf)
	Set maximum number of elements stored in a leaf node of the GNAT.
unsigned int	getMaxNumPtsPerLeaf () const
	Get maximum number of elements stored in a leaf node of the GNAT.
void	setEstimatedDimension (double estimatedDimension)
	Set estimated dimension of the free space, which is needed to compute the sampling weight for a node in the GNAT.
double	getEstimatedDimension () const
	Get estimated dimension of the free space, which is needed to compute the sampling weight for a node in the GNAT.
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	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).
double	getMinValidPathFraction () const
	Get the value of the fraction set by setMinValidPathFraction()
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	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	freeMemory ()
	Free the memory allocated by this planner.
void	setupTree ()
	Initialize GNAT data structure.
double	distanceFunction (const Motion *a, const Motion *b) const
	Compute distance between motions (actually distance between contained states)
double	projectedDistanceFunction (const Motion *a, const Motion *b) const
	Compute distance between motions (actually distance between projections of contained states)
void	addMotion (Motion *motion)
	Add a motion to the exploration tree.
Motion *	selectMotion ()
	Select a motion to continue the expansion of the tree from.
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::ValidStateSamplerPtr	sampler_
	Valid state sampler.
base::ProjectionEvaluatorPtr	projectionEvaluator_
	This algorithm can optionally use a projection to guide the exploration.
boost::scoped_ptr< NearestNeighborsGNAT< Motion * > >	tree_
	The exploration tree constructed by this algorithm.
double	goalBias_ {.05}
	The fraction of time the goal is picked as the state to expand towards (if such a state is available)
double	maxDistance_ {0.}
	The maximum length of a motion to be added to a tree.
bool	useProjectedDistance_
	Whether to use distance in the projection (instead of distance in the state space) for the GNAT.
unsigned int	degree_
	Desired degree of an internal node in the GNAT.
unsigned int	minDegree_
	Minimum degree of an internal node in the GNAT.
unsigned int	maxDegree_
	Maximum degree of an internal node in the GNAT.
unsigned int	maxNumPtsPerLeaf_
	Maximum number of points stored in a leaf node in the GNAT.
double	estimatedDimension_
	Estimate of the local dimensionality of the free space around a state.
double	minValidPathFraction_ {.2}
	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 is used only when extendWhileValid_ is true.
RNG	rng_
	The random number generator.
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

Search Tree with Resolution Independent Density Estimation.

Short description

STRIDE (Search Tree with Resolution Independent Density Estimation) is a tree-based motion planner that attempts to detect the less explored area of the space through the use of a GNAT nearest-neighbor data structure. It is similar to EST, but unlike the EST implementation in OMPL does not require a projection. However, in case the state space has many dimensions, a projection can be specified and the GNAT can be built using distances in the projected space. This has the advantage over the EST implementation that no grid cell sizes have to be specified.

External documentation

B. Gipson, M. Moll, and L.E. Kavraki, Resolution independent density estimation for motion planning in high-dimensional spaces, in IEEE Intl. Conf. on Robotics and Automation, pp. 2429-2435, 2013. [PDF]

Definition at line 110 of file STRIDE.h.

Member Function Documentation

setRange()

void ompl::geometric::STRIDE::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 220 of file STRIDE.h.

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

• ompl/geometric/planners/stride/STRIDE.h
• ompl/geometric/planners/stride/src/STRIDE.cpp