Probabilistic RoadMap planner. More...
#include <PRM.h>
Classes | |
struct | vertex_state_t |
struct | vertex_successful_connection_attempts_t |
struct | vertex_total_connection_attempts_t |
Public Types | |
typedef boost::adjacency_list < boost::vecS, boost::vecS, boost::undirectedS, boost::property < vertex_state_t, base::State *, boost::property < vertex_total_connection_attempts_t, unsigned int, boost::property < vertex_successful_connection_attempts_t, unsigned int, boost::property < boost::vertex_predecessor_t, unsigned long int, boost::property < boost::vertex_rank_t, unsigned long int > > > > >, boost::property < boost::edge_weight_t, double, boost::property < boost::edge_index_t, unsigned int > > > | Graph |
The underlying roadmap graph. | |
typedef boost::graph_traits < Graph >::vertex_descriptor | Vertex |
typedef boost::graph_traits < Graph >::edge_descriptor | Edge |
typedef boost::shared_ptr < NearestNeighbors< Vertex > > | RoadmapNeighbors |
typedef boost::function1 < std::vector< Vertex > &, const Vertex > | ConnectionStrategy |
A function returning the milestones that should be attempted to connect to. | |
typedef boost::function2< bool, const Vertex &, const Vertex & > | ConnectionFilter |
A function that can reject connections. | |
Public Member Functions | |
PRM (const base::SpaceInformationPtr &si, bool starStrategy=false) | |
Constructor. | |
virtual void | setProblemDefinition (const base::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(). | |
void | setConnectionStrategy (const ConnectionStrategy &connectionStrategy) |
Set the connection strategy function that specifies the milestones that connection attempts will be make to for a given milestone. | |
void | setMaxNearestNeighbors (unsigned int k) |
Convenience function that sets the connection strategy to the default one with k nearest neighbors. | |
void | setConnectionFilter (const ConnectionFilter &connectionFilter) |
Set the function that can reject a milestone connection. | |
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 void | growRoadmap (double growTime) |
If the user desires, the roadmap can be improved for a specified amount of time. The solve() method will also improve the roadmap, as needed. | |
virtual void | expandRoadmap (double expandTime) |
Attempt to connect disjoint components in the roadmap using random bounding motions (the PRM expansion step) | |
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 void | clear (void) |
Clear all internal datastructures. Planner settings are not affected. Subsequent calls to solve() will ignore all previous work. | |
template<template< typename T > class NN> | |
void | setNearestNeighbors (void) |
Set a different nearest neighbors datastructure. | |
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. | |
const Graph & | getRoadmap (void) const |
double | distanceFunction (const Vertex a, const Vertex b) const |
Compute distance between two milestones (this is simply distance between the states of the milestones) | |
unsigned int | milestoneCount (void) const |
Compute distance between two milestones (this is simply distance between the states of the milestones) | |
const RoadmapNeighbors & | getNearestNeighbors (void) |
Protected Member Functions | |
void | freeMemory (void) |
Free all the memory allocated by the planner. | |
Vertex | addMilestone (base::State *state) |
Construct a milestone for a given state (state) and store it in the nearest neighbors data structure. | |
void | uniteComponents (Vertex m1, Vertex m2) |
Make two milestones (m1 and m2) be part of the same connected component. The component with fewer elements will get the id of the component with more elements. | |
void | growRoadmap (const std::vector< Vertex > &start, const std::vector< Vertex > &goal, const base::PlannerTerminationCondition &ptc, base::State *workState) |
Randomly sample the state space, add and connect milestones in the roadmap. Stop this process when the termination condition ptc returns true or when any of the start milestones are in the same connected component as any of the goal milestones. Use workState as temporary memory. | |
void | expandRoadmap (const std::vector< Vertex > &starts, const std::vector< Vertex > &goals, const base::PlannerTerminationCondition &ptc, std::vector< base::State * > &workStates) |
Attempt to connect disjoint components in the roadmap using random bounding motions (the PRM expansion step) | |
bool | haveSolution (const std::vector< Vertex > &start, const std::vector< Vertex > &goal, std::pair< Vertex, Vertex > *endpoints=NULL) |
Check if there exists a solution, i.e., there exists a pair of milestones such that the first is in start and the second is in goal, and the two milestones are in the same connected component. If endpoints is not null, that pair is recorded. | |
base::PathPtr | constructSolution (const Vertex start, const Vertex goal) |
Given two milestones from the same connected component, construct a path connecting them and set it as the solution. | |
Protected Attributes | |
bool | starStrategy_ |
Flag indicating whether the default strategy is the Star trategy or not. | |
base::ValidStateSamplerPtr | sampler_ |
Sampler user for generating valid samples in the state space. | |
base::StateSamplerPtr | simpleSampler_ |
Sampler user for generating random in the state space. | |
RoadmapNeighbors | nn_ |
Nearest neighbors data structure. | |
Graph | g_ |
Connectivity graph. | |
std::vector< Vertex > | startM_ |
Array of start milestones. | |
std::vector< Vertex > | goalM_ |
Array of goal milestones. | |
base::PathPtr | approxsol_ |
Storage for approximate solutions. | |
double | approxlen_ |
The length of the approximate solution. | |
boost::property_map< Graph, vertex_state_t >::type | stateProperty_ |
Access to the internal base::state at each Vertex. | |
boost::property_map< Graph, vertex_total_connection_attempts_t > ::type | totalConnectionAttemptsProperty_ |
Access to the number of total connection attempts for a vertex. | |
boost::property_map< Graph, vertex_successful_connection_attempts_t > ::type | successfulConnectionAttemptsProperty_ |
Access to the number of successful connection attempts for a vertex. | |
boost::property_map< Graph, boost::edge_weight_t >::type | weightProperty_ |
Access to the weights of each Edge. | |
boost::property_map< Graph, boost::edge_index_t >::type | edgeIDProperty_ |
Access to the indices of each Edge. | |
boost::disjoint_sets < boost::property_map< Graph, boost::vertex_rank_t >::type, boost::property_map< Graph, boost::vertex_predecessor_t > ::type > | disjointSets_ |
Data structure that maintains the connected components. | |
unsigned int | maxEdgeID_ |
Maximum unique id number used so for for edges. | |
ConnectionStrategy | connectionStrategy_ |
Function that returns the milestones to attempt connections with. | |
ConnectionFilter | connectionFilter_ |
Function that can reject a milestone connection. | |
bool | userSetConnectionStrategy_ |
Flag indicating whether the employed connection strategy was set by the user (or defaults are assumed) | |
RNG | rng_ |
Random number generator. |
Probabilistic RoadMap planner.
@par Short description PRM is a planner that constructs a roadmap of milestones that approximate the connectivity of the state space. The milestones are valid states in the state space. Near-by milestones are connected by valid motions. Finding a motion plan that connects two given states is reduced to a discrete search (this implementation uses A*) in the roadmap. @par External documentation L.E. Kavraki, P.Švestka, J.-C. Latombe, and M.H. Overmars, Probabilistic roadmaps for path planning in high-dimensional configuration spaces, <em>IEEE Trans. on Robotics and Automation</em>, vol. 12, pp. 566–580, Aug. 1996. DOI: <a href="http://dx.doi.org/10.1109/70.508439">10.1109/70.508439</a><br> <a href="http://ieeexplore.ieee.org/ielx4/70/11078/00508439.pdf?tp=&arnumber=508439&isnumber=11078">[PDF]</a> <a href="http://www.kavrakilab.org/robotics/prm.html">[more]</a>
typedef boost::function2<bool, const Vertex&, const Vertex&> ompl::geometric::PRM::ConnectionFilter |
typedef boost::function1<std::vector<Vertex>&, const Vertex> ompl::geometric::PRM::ConnectionStrategy |
typedef boost::adjacency_list< boost::vecS, boost::vecS, boost::undirectedS, boost::property < vertex_state_t, base::State*, boost::property < vertex_total_connection_attempts_t, unsigned int, boost::property < vertex_successful_connection_attempts_t, unsigned int, boost::property < boost::vertex_predecessor_t, unsigned long int, boost::property < boost::vertex_rank_t, unsigned long int > > > > >, boost::property < boost::edge_weight_t, double, boost::property < boost::edge_index_t, unsigned int> > > ompl::geometric::PRM::Graph |
The underlying roadmap graph.
void ompl::geometric::PRM::setConnectionFilter | ( | const ConnectionFilter & | connectionFilter | ) | [inline] |
Set the function that can reject a milestone connection.
connectionFilter | A function that takes the new milestone, a neighboring milestone and returns whether a connection should be attempted. |
void ompl::geometric::PRM::setConnectionStrategy | ( | const ConnectionStrategy & | connectionStrategy | ) | [inline] |
Set the connection strategy function that specifies the milestones that connection attempts will be make to for a given milestone.
pdef | A function that takes a milestone as an argument and returns a collection of other milestones to which a connection attempt must be made. The default connection strategy is to connect a milestone's 10 closest neighbors. |