ompl::geometric::PDST Class Reference

Path-Directed Subdivision Tree. More...

#include <ompl/geometric/planners/pdst/PDST.h>

Inheritance diagram for ompl::geometric::PDST:

List of all members.

Classes

struct  Cell
 Cell is a Binary Space Partition. More...
struct  Motion
 Class representing the tree of motions exploring the state space. More...
struct  MotionCompare
 Comparator used to order motions in the priority queue. More...

Public Member Functions

 PDST (const base::SpaceInformationPtr &si)
virtual base::PlannerStatus 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 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). The function terminates if the call to ptc returns true.
virtual void clear ()
 Clear all internal datastructures. Planner settings are not affected. Subsequent calls to solve() will ignore all previous work.
virtual void setup ()
 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 void getPlannerData (base::PlannerData &data) const
 Extracts the planner data from the priority queue into data.
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 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 */.

Protected Member Functions

void addMotion (Motion *motion, Cell *cell, base::State *, base::EuclideanProjection &)
 Inserts the motion into the appropriate cell.
void updateHeapElement (Motion *motion)
 Either update heap after motion's priority has changed or insert motion into heap.
MotionpropagateFrom (Motion *motion, base::State *, base::State *)
 Select a state along motion and propagate a new motion from there. Return NULL if no valid motion could be generated starting at the selected state.
void freeMemory ()

Protected Attributes

ompl::base::StateSamplerPtr sampler_
 State sampler.
RNG rng_
std::vector< Motion * > startMotions_
 Vector holding all of the start states supplied for the problem Each start motion is the root of its own tree of motions.
ompl::BinaryHeap< Motion
*, MotionCompare
priorityQueue_
 Priority queue of motions.
Cellbsp_
 Binary Space Partition.
ompl::base::ProjectionEvaluatorPtr projectionEvaluator_
 Projection evaluator for the problem.
double goalBias_
 Number between 0 and 1 specifying the probability with which the goal should be sampled.
ompl::base::GoalSampleableRegion * goalSampler_
 Objected used to sample the goal.
unsigned int iteration_
 Iteration number and priority of the next Motion that will be generated.
MotionlastGoalMotion_
 Closest motion to the goal.

Detailed Description

Path-Directed Subdivision Tree.

Short description
PDST is a tree-based motion planner that attempts to detect the less explored area of the space through the use of a binary space partition of a projection of the state space. Exploration is biased towards large cells with few path segments. Unlike most tree-based planners which expand from a randomly select endpoint of a path segment, PDST expands from a randomly selected point along a deterministically selected path segment. 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
A.M. Ladd and L.E. Kavraki, Motion planning in the presence of drift, underactuation and discrete system changes, in Robotics: Science and Systems I, pp. 233–241, MIT Press, June 2005. [[PDF]](http://www.roboticsproceedings.org/rss01/p31.pdf)

Definition at line 80 of file PDST.h.


The documentation for this class was generated from the following files:
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Defines