BFMT.h

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/* Authors: Joseph Starek (Stanford) */
/* Co-developers: Javier V Gomez (UC3M)*/
/* Algorithm design: Joseph Starek (Stanford), Ed Schmerling (Stanford), Lucas Janson (Stanford) and Marco Pavone
 * (Stanford) */
/* Acknowledgements for insightful comments: Ashley Clark (Stanford) */
 
#ifndef OMPL_GEOMETRIC_PLANNERS_BIDIRECTIONALFMT_H
#define OMPL_GEOMETRIC_PLANNERS_BIDIRECTIONALFMT_H
 
#include <ompl/geometric/planners/PlannerIncludes.h>
#include <ompl/base/goals/GoalSampleableRegion.h>
#include <ompl/datastructures/NearestNeighbors.h>
#include <ompl/datastructures/BinaryHeap.h>
#include <ompl/base/OptimizationObjective.h>
#include <map>
#include <utility>
 
namespace ompl
{
    namespace geometric
    {
        class BFMT : public ompl::base::Planner
        {
        public:
            enum TreeType
            {
                FWD = 0,
                REV = 1
            };
 
            enum ExploreType
            {
                SWAP_EVERY_TIME = 0,
                CHOOSE_SMALLEST_Z = 1
            };
 
            enum TerminateType
            {
                FEASIBILITY = 0,
                OPTIMALITY = 1
            };
 
            BFMT(const base::SpaceInformationPtr &si);
 
            ~BFMT() override;
 
            void setup() override;
 
            base::PlannerStatus solve(const base::PlannerTerminationCondition &ptc) override;
 
            void clear() override;
 
            void getPlannerData(base::PlannerData &data) const override;
 
            void setNumSamples(const unsigned int numSamples)
            {
                numSamples_ = numSamples;
            }
 
            unsigned int getNumSamples() const
            {
                return numSamples_;
            }
 
            void setNearestK(bool nearestK)
            {
                nearestK_ = nearestK;
            }
 
            bool getNearestK() const
            {
                return nearestK_;
            }
 
            void setRadiusMultiplier(const double radiusMultiplier)
            {
                if (radiusMultiplier <= 0.0)
                    throw Exception("Radius multiplier must be greater than zero");
                radiusMultiplier_ = radiusMultiplier;
            }
 
            double getRadiusMultiplier() const
            {
                return radiusMultiplier_;
            }
 
            void setFreeSpaceVolume(const double freeSpaceVolume)
            {
                if (freeSpaceVolume < 0.0)
                    throw Exception("Free space volume should be greater than zero");
                freeSpaceVolume_ = freeSpaceVolume;
            }
 
            double getFreeSpaceVolume() const
            {
                return freeSpaceVolume_;
            }
 
            void setCacheCC(bool ccc)
            {
                cacheCC_ = ccc;
            }
 
            bool getCacheCC() const
            {
                return cacheCC_;
            }
 
            void setHeuristics(bool h)
            {
                heuristics_ = h;
            }
 
            bool getHeuristics() const
            {
                return heuristics_;
            }
 
            void setExtendedFMT(bool e)
            {
                extendedFMT_ = e;
            }
 
            bool getExtendedFMT() const
            {
                return extendedFMT_;
            }
 
            void setExploration(bool balanced)
            {
                exploration_ = SWAP_EVERY_TIME;
                if (balanced)
                {
                    exploration_ = CHOOSE_SMALLEST_Z;
                }
            }
 
            bool getExploration() const
            {
                return (exploration_ == CHOOSE_SMALLEST_Z);
            }
 
            void setTermination(bool optimality)
            {
                termination_ = FEASIBILITY;
                if (optimality)
                {
                    termination_ = OPTIMALITY;
                }
            }
 
            bool getTermination() const
            {
                return (termination_ == OPTIMALITY);
            }
 
            void setPrecomputeNN(bool p)
            {
                precomputeNN_ = p;
            }
 
            bool setPrecomputeNN() const
            {
                return precomputeNN_;
            }
 
            class BiDirMotion
            {
            public:
                enum SetType
                {
                    SET_CLOSED,
                    SET_OPEN,
                    SET_UNVISITED
                };
 
                BiDirMotion(TreeType *tree) : state_(nullptr), tree_(tree)
                {
                    parent_[FWD] = nullptr;
                    parent_[REV] = nullptr;
                    cost_[FWD] = base::Cost(0.0);
                    cost_[REV] = base::Cost(0.0);
                    hcost_[FWD] = base::Cost(0.0);
                    hcost_[REV] = base::Cost(0.0);
                    currentSet_[FWD] = SET_UNVISITED;
                    currentSet_[REV] = SET_UNVISITED;
                }
 
                BiDirMotion(const base::SpaceInformationPtr &si, TreeType *tree) : state_(si->allocState()), tree_(tree)
                {
                    parent_[FWD] = nullptr;
                    parent_[REV] = nullptr;
                    cost_[FWD] = base::Cost(0.0);
                    cost_[REV] = base::Cost(0.0);
                    hcost_[FWD] = base::Cost(0.0);
                    hcost_[REV] = base::Cost(0.0);
                    currentSet_[FWD] = SET_UNVISITED;
                    currentSet_[REV] = SET_UNVISITED;
                }
 
                using BiDirMotionPtrs = std::vector<BiDirMotion *>;
 
                base::State *state_;
 
                BiDirMotion *parent_[2];
 
                BiDirMotionPtrs children_[2];
 
                SetType currentSet_[2];
 
                TreeType *tree_;
 
                base::Cost cost_[2];
 
                base::Cost hcost_[2];
 
                std::set<BiDirMotion *> collChecksDone_;
 
                inline base::Cost getCost() const
                {
                    return this->cost_[*tree_];
                }
 
                inline base::Cost getOtherCost() const
                {
                    return this->cost_[(*tree_ + 1) % 2];
                }
 
                inline void setCost(base::Cost cost)
                {
                    this->cost_[*tree_] = cost;
                }
 
                inline void setParent(BiDirMotion *parent)
                {
                    this->parent_[*tree_] = parent;
                }
 
                inline BiDirMotion *getParent() const
                {
                    return this->parent_[*tree_];
                }
 
                inline void setChildren(BiDirMotionPtrs children)
                {
                    this->children_[*tree_] = std::move(children);
                }
 
                inline BiDirMotionPtrs getChildren() const
                {
                    return this->children_[*tree_];
                }
 
                inline void setCurrentSet(SetType set)
                {
                    this->currentSet_[*tree_] = set;
                }
 
                inline SetType getCurrentSet() const
                {
                    return this->currentSet_[*tree_];
                }
 
                inline SetType getOtherSet() const
                {
                    return this->currentSet_[(*tree_ + 1) % 2];
                }
 
                inline void setTreeType(TreeType *treePtr)
                {
                    this->tree_ = treePtr;
                }
 
                inline TreeType getTreeType() const
                {
                    return *tree_;
                }
 
                void setState(base::State *state)
                {
                    state_ = state;
                }
 
                base::State *getState() const
                {
                    return state_;
                }
 
                bool alreadyCC(BiDirMotion *m)
                {
                    return !(collChecksDone_.find(m) == collChecksDone_.end());
                }
 
                void addCC(BiDirMotion *m)
                {
                    collChecksDone_.insert(m);
                }
 
                void setHeuristicCost(const base::Cost h)
                {
                    hcost_[*tree_] = h;
                }
 
                base::Cost getHeuristicCost() const
                {
                    return hcost_[*tree_];
                }
            };
 
            using BiDirMotionPtrs = std::vector<BiDirMotion *>;
 
        protected:
            struct BiDirMotionCompare
            {
                bool operator()(const BiDirMotion *p1, const BiDirMotion *p2) const
                {
                    if (heuristics_)
                        return (opt_->combineCosts(p1->getCost(), p1->getHeuristicCost()).value() <
                                opt_->combineCosts(p2->getCost(), p2->getHeuristicCost()).value());
                    return (p1->getCost().value() < p2->getCost().value());
                }
 
                base::OptimizationObjective *opt_;
                bool heuristics_;
            };
 
            using BiDirMotionBinHeap = ompl::BinaryHeap<BiDirMotion *, BiDirMotionCompare>;
 
            void swapTrees();
 
            void useFwdTree()
            {
                tree_ = FWD;
            }
 
            void useRevTree()
            {
                tree_ = REV;
            }
 
            double distanceFunction(const BiDirMotion *a, const BiDirMotion *b) const
            {
                return opt_->motionCost(a->getState(), b->getState()).value();
            }
 
            double calculateUnitBallVolume(unsigned int dimension) const;
 
            double calculateRadius(unsigned int dimension, unsigned int n) const;
 
            void freeMemory();
 
            void saveNeighborhood(BiDirMotion *m);
 
            void sampleFree(const std::shared_ptr<NearestNeighbors<BiDirMotion *>> &nn,
                            const base::PlannerTerminationCondition &ptc);
 
            void initializeProblem(base::GoalSampleableRegion *&goal_s);
 
            void expandTreeFromNode(BiDirMotion *&z, BiDirMotion *&connection_point);
 
            bool plan(BiDirMotion *x_init, BiDirMotion *x_goal, BiDirMotion *&connection_point,
                      const base::PlannerTerminationCondition &ptc);
 
            bool termination(BiDirMotion *&z, BiDirMotion *&connection_point,
                             const base::PlannerTerminationCondition &ptc);
 
            void chooseTreeAndExpansionNode(BiDirMotion *&z);
 
            void tracePath(BiDirMotion *z, BiDirMotionPtrs &path);
 
            void updateNeighborhood(BiDirMotion *m, std::vector<BiDirMotion *> nbh);
 
            void insertNewSampleInOpen(const base::PlannerTerminationCondition &ptc);
 
            unsigned int numSamples_{1000u};
 
            double radiusMultiplier_{1.};
 
            double freeSpaceVolume_;
 
            unsigned int collisionChecks_{0u};
 
            bool nearestK_{true};
 
            double NNr_{0.};
 
            unsigned int NNk_{0};
 
            TreeType tree_{FWD};
 
            ExploreType exploration_{SWAP_EVERY_TIME};
 
            TerminateType termination_{OPTIMALITY};
 
            bool precomputeNN_{false};
 
            std::shared_ptr<NearestNeighbors<BiDirMotion *>> nn_;
 
            std::map<BiDirMotion *, BiDirMotionPtrs> neighborhoods_;
 
            BiDirMotionBinHeap Open_[2];
 
            std::map<BiDirMotion *, BiDirMotionBinHeap::Element *> Open_elements[2];
 
            base::StateSamplerPtr sampler_;
 
            base::OptimizationObjectivePtr opt_;
 
            bool heuristics_{true};
 
            base::State *heurGoalState_[2];
 
            bool cacheCC_{true};
 
            bool extendedFMT_{true};
 
            // For sorting a list of costs and getting only their sorted indices
            struct CostIndexCompare
            {
                CostIndexCompare(const std::vector<base::Cost> &costs, const base::OptimizationObjective &opt)
                  : costs_(costs), opt_(opt)
                {
                }
                bool operator()(unsigned i, unsigned j)
                {
                    return (costs_[i].value() < costs_[j].value());
                }
                const std::vector<base::Cost> &costs_;
                const base::OptimizationObjective &opt_;
            };
        };
 
    }  // End "geometric" namespace
}  // End "ompl" namespace
 
#endif /* OMPL_GEOMETRIC_PLANNERS_BIDIRECTIONALFMT_H */