ompl::geometric::LazyRRT Class Reference

Lazy RRT. More...

#include <ompl/geometric/planners/rrt/LazyRRT.h>

Inheritance diagram for ompl::geometric::LazyRRT:

List of all members.

Classes

class  Motion
 Representation of a motion. More...

Public Member Functions

 LazyRRT (const base::SpaceInformationPtr &si)
 Constructor.
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).
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.
void setGoalBias (double goalBias)
 Set the goal biasing.
double getGoalBias () const
 Get the goal bias the planner is using.
void setRange (double distance)
 Set the range the planner is supposed to use.
double getRange () const
 Get the range the planner is using.
template<template< typename T > class NN>
void setNearestNeighbors ()
 Set a different nearest neighbors datastructure.
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.

Protected Member Functions

void freeMemory ()
 Free the memory allocated by this planner.
void removeMotion (Motion *motion)
 Remove a motion from the tree datastructure.
double distanceFunction (const Motion *a, const Motion *b) const
 Compute distance between motions (actually distance between contained states)

Protected Attributes

base::StateSamplerPtr sampler_
 State sampler.
boost::shared_ptr
< NearestNeighbors< Motion * > > 
nn_
 A nearest-neighbors datastructure containing the tree of motions.
double goalBias_
 The fraction of time the goal is picked as the state to expand towards (if such a state is available)
double maxDistance_
 The maximum length of a motion to be added to a tree.
RNG rng_
 The random number generator.
MotionlastGoalMotion_
 The most recent goal motion. Used for PlannerData computation.

Detailed Description

Lazy RRT.

Short description
RRT is a tree-based motion planner that uses the following idea: RRT samples a random state qr in the state space, then finds the state qc among the previously seen states that is closest to qr and expands from qc towards qr, until a state qm is reached. qm is then added to the exploration tree. The difference between RRT and LazyRRT is that when moving towards the new state qm, LazyRRT does not check to make sure the path is valid. Instead, it is optimistic and attempts to find a path as soon as possible. Once a path is found, it is checked for collision. If collisions are found, the invalid path segments are removed and the search process is continued.
External documentation

Definition at line 78 of file LazyRRT.h.


Member Function Documentation

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

Set the goal biasing.

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 102 of file LazyRRT.h.

void ompl::geometric::LazyRRT::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 118 of file LazyRRT.h.


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