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Protected Types |
Protected Member Functions |
Protected Attributes
ompl::geometric::SBL Class Reference
Single-Query Bi-Directional Probabilistic Roadmap Planner with Lazy Collision Checking. More...
#include <ompl/geometric/planners/sbl/SBL.h>
Inheritance diagram for ompl::geometric::SBL:

Classes | |
class | Motion |
Representation of a motion. More... | |
struct | MotionInfo |
A struct containing an array of motions and a corresponding PDF element. More... | |
struct | TreeData |
Representation of a search tree. Two instances will be used. One for start and one for goal. More... | |
Public Member Functions | |
SBL (const base::SpaceInformationPtr &si) | |
The constructor needs the instance of the space information. | |
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. | |
double | getRange () const |
Get the range the planner is using. | |
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 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 | 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). | |
Protected Types | |
typedef Grid< MotionInfo >::Cell | GridCell |
A grid cell. | |
typedef PDF< GridCell * > | CellPDF |
A PDF of grid cells. | |
Protected Member Functions | |
void | freeMemory () |
Free the memory allocated by the planner. | |
void | freeGridMotions (Grid< MotionInfo > &grid) |
Free the memory used by the motions contained in a grid. | |
void | addMotion (TreeData &tree, Motion *motion) |
Add a motion to a tree. | |
Motion * | selectMotion (TreeData &tree) |
Select a motion from a tree. | |
void | removeMotion (TreeData &tree, Motion *motion) |
Remove a motion from a tree. | |
bool | isPathValid (TreeData &tree, Motion *motion) |
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. | |
bool | checkSolution (bool start, TreeData &tree, TreeData &otherTree, Motion *motion, std::vector< Motion * > &solution) |
Check if a solution can be obtained by connecting two trees using a specified motion. | |
Protected Attributes | |
base::ValidStateSamplerPtr | sampler_ |
The employed state sampler. | |
base::ProjectionEvaluatorPtr | projectionEvaluator_ |
The employed projection evaluator. | |
TreeData | tStart_ |
The start tree. | |
TreeData | tGoal_ |
The goal tree. | |
double | maxDistance_ |
The maximum length of a motion to be added in the tree. | |
RNG | rng_ |
The random number generator to be used. | |
std::pair< base::State *, base::State * > | connectionPoint_ |
The pair of states in each tree connected during planning. Used for PlannerData computation. |
Detailed Description
Single-Query Bi-Directional Probabilistic Roadmap Planner with Lazy Collision Checking.
- Short description
- SBL is a tree-based motion planner that attempts to grow two trees at once: one grows from the starting state and the other from the goal state. The tree expansion strategy is the same as for EST. Attempts are made to connect these trees at every step of the expansion. If they are connected, a solution path is obtained. However, this solution path is not certain to be valid (the lazy part of the algorithm) so it is checked for validity. If invalid parts are found, they are removed from the tree and exploration of the state space continues until a solution is found. To guide the exploration, an additional grid data structure is maintained. Grid cells contain states that have been previously visited. When deciding which state to use for further expansion, this grid is used; least-filled grid cells have most chances of being selected. The grid is usually imposed on a projection of the state space. This projection needs to be set before using the planner (setProjectionEvaluator() function). Connection of states in different trees is attempted if they fall in the same grid cell. 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
- G. Sánchez and J.-C. Latombe, A single-query bi-directional probabilistic roadmap planner with lazy collision checking, in The Tenth International Symposium on Robotics Research, pp. 403–417, 2001. DOI: [10.1007/3-540-36460-9_27](http://dx.doi.org/10.1007/3-540-36460-9_27)
[[PDF]](http://www.springerlink.com/content/9843341054386hh6/fulltext.pdf)
Member Function Documentation
void ompl::geometric::SBL::setRange | ( | double | distance | ) | [inline] |
The documentation for this class was generated from the following files: