ompl/control/planners/rrt/src/RRT.cpp
00001 /*********************************************************************
00002 * Software License Agreement (BSD License)
00003 *
00004 *  Copyright (c) 2008, Willow Garage, Inc.
00005 *  All rights reserved.
00006 *
00007 *  Redistribution and use in source and binary forms, with or without
00008 *  modification, are permitted provided that the following conditions
00009 *  are met:
00010 *
00011 *   * Redistributions of source code must retain the above copyright
00012 *     notice, this list of conditions and the following disclaimer.
00013 *   * Redistributions in binary form must reproduce the above
00014 *     copyright notice, this list of conditions and the following
00015 *     disclaimer in the documentation and/or other materials provided
00016 *     with the distribution.
00017 *   * Neither the name of the Willow Garage nor the names of its
00018 *     contributors may be used to endorse or promote products derived
00019 *     from this software without specific prior written permission.
00020 *
00021 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
00022 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
00023 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
00024 *  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
00025 *  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
00026 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
00027 *  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
00028 *  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
00029 *  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
00030 *  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
00031 *  ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
00032 *  POSSIBILITY OF SUCH DAMAGE.
00033 *********************************************************************/
00034 
00035 /* Author: Ioan Sucan */
00036 
00037 #include "ompl/control/planners/rrt/RRT.h"
00038 #include "ompl/base/goals/GoalSampleableRegion.h"
00039 #include "ompl/tools/config/SelfConfig.h"
00040 #include <limits>
00041 
00042 ompl::control::RRT::RRT(const SpaceInformationPtr &si) : base::Planner(si, "RRT")
00043 {
00044     specs_.approximateSolutions = true;
00045     siC_ = si.get();
00046     addIntermediateStates_ = false;
00047     lastGoalMotion_ = NULL;
00048 
00049     goalBias_ = 0.05;
00050 
00051     Planner::declareParam<double>("goal_bias", this, &RRT::setGoalBias, &RRT::getGoalBias, "0.:.05:1.");
00052     Planner::declareParam<bool>("intermediate_states", this, &RRT::setIntermediateStates, &RRT::getIntermediateStates);
00053 }
00054 
00055 ompl::control::RRT::~RRT()
00056 {
00057     freeMemory();
00058 }
00059 
00060 void ompl::control::RRT::setup()
00061 {
00062     base::Planner::setup();
00063     if (!nn_)
00064         nn_.reset(tools::SelfConfig::getDefaultNearestNeighbors<Motion*>(si_->getStateSpace()));
00065     nn_->setDistanceFunction(boost::bind(&RRT::distanceFunction, this, _1, _2));
00066 }
00067 
00068 void ompl::control::RRT::clear()
00069 {
00070     Planner::clear();
00071     sampler_.reset();
00072     controlSampler_.reset();
00073     freeMemory();
00074     if (nn_)
00075         nn_->clear();
00076     lastGoalMotion_ = NULL;
00077 }
00078 
00079 void ompl::control::RRT::freeMemory()
00080 {
00081     if (nn_)
00082     {
00083         std::vector<Motion*> motions;
00084         nn_->list(motions);
00085         for (unsigned int i = 0 ; i < motions.size() ; ++i)
00086         {
00087             if (motions[i]->state)
00088                 si_->freeState(motions[i]->state);
00089             if (motions[i]->control)
00090                 siC_->freeControl(motions[i]->control);
00091             delete motions[i];
00092         }
00093     }
00094 }
00095 
00096 ompl::base::PlannerStatus ompl::control::RRT::solve(const base::PlannerTerminationCondition &ptc)
00097 {
00098     checkValidity();
00099     base::Goal                   *goal = pdef_->getGoal().get();
00100     base::GoalSampleableRegion *goal_s = dynamic_cast<base::GoalSampleableRegion*>(goal);
00101 
00102     while (const base::State *st = pis_.nextStart())
00103     {
00104         Motion *motion = new Motion(siC_);
00105         si_->copyState(motion->state, st);
00106         siC_->nullControl(motion->control);
00107         nn_->add(motion);
00108     }
00109 
00110     if (nn_->size() == 0)
00111     {
00112         OMPL_ERROR("%s: There are no valid initial states!", getName().c_str());
00113         return base::PlannerStatus::INVALID_START;
00114     }
00115 
00116     if (!sampler_)
00117         sampler_ = si_->allocStateSampler();
00118     if (!controlSampler_)
00119         controlSampler_ = siC_->allocDirectedControlSampler();
00120 
00121     OMPL_INFORM("%s: Starting planning with %u states already in datastructure", getName().c_str(), nn_->size());
00122 
00123     Motion *solution  = NULL;
00124     Motion *approxsol = NULL;
00125     double  approxdif = std::numeric_limits<double>::infinity();
00126 
00127     Motion      *rmotion = new Motion(siC_);
00128     base::State  *rstate = rmotion->state;
00129     Control       *rctrl = rmotion->control;
00130     base::State  *xstate = si_->allocState();
00131 
00132     while (ptc == false)
00133     {
00134         /* sample random state (with goal biasing) */
00135         if (goal_s && rng_.uniform01() < goalBias_ && goal_s->canSample())
00136             goal_s->sampleGoal(rstate);
00137         else
00138             sampler_->sampleUniform(rstate);
00139 
00140         /* find closest state in the tree */
00141         Motion *nmotion = nn_->nearest(rmotion);
00142 
00143         /* sample a random control that attempts to go towards the random state, and also sample a control duration */
00144         unsigned int cd = controlSampler_->sampleTo(rctrl, nmotion->control, nmotion->state, rmotion->state);
00145 
00146         if (addIntermediateStates_)
00147         {
00148             // this code is contributed by Jennifer Barry
00149             std::vector<base::State *> pstates;
00150             cd = siC_->propagateWhileValid(nmotion->state, rctrl, cd, pstates, true);
00151 
00152             if (cd >= siC_->getMinControlDuration())
00153             {
00154                 Motion *lastmotion = nmotion;
00155                 bool solved = false;
00156                 size_t p = 0;
00157                 for ( ; p < pstates.size(); ++p)
00158                 {
00159                     /* create a motion */
00160                     Motion *motion = new Motion();
00161                     motion->state = pstates[p];
00162                     //we need multiple copies of rctrl
00163                     motion->control = siC_->allocControl();
00164                     siC_->copyControl(motion->control, rctrl);
00165                     motion->steps = 1;
00166                     motion->parent = lastmotion;
00167                     lastmotion = motion;
00168                     nn_->add(motion);
00169                     double dist = 0.0;
00170                     solved = goal->isSatisfied(motion->state, &dist);
00171                     if (solved)
00172                     {
00173                         approxdif = dist;
00174                         solution = motion;
00175                         break;
00176                     }
00177                     if (dist < approxdif)
00178                     {
00179                         approxdif = dist;
00180                         approxsol = motion;
00181                     }
00182                 }
00183 
00184                 //free any states after we hit the goal
00185                 while (++p < pstates.size())
00186                     si_->freeState(pstates[p]);
00187                 if (solved)
00188                     break;
00189             }
00190             else
00191                 for (size_t p = 0 ; p < pstates.size(); ++p)
00192                     si_->freeState(pstates[p]);
00193         }
00194         else
00195         {
00196             if (cd >= siC_->getMinControlDuration())
00197             {
00198                 /* create a motion */
00199                 Motion *motion = new Motion(siC_);
00200                 si_->copyState(motion->state, rmotion->state);
00201                 siC_->copyControl(motion->control, rctrl);
00202                 motion->steps = cd;
00203                 motion->parent = nmotion;
00204 
00205                 nn_->add(motion);
00206                 double dist = 0.0;
00207                 bool solv = goal->isSatisfied(motion->state, &dist);
00208                 if (solv)
00209                 {
00210                     approxdif = dist;
00211                     solution = motion;
00212                     break;
00213                 }
00214                 if (dist < approxdif)
00215                 {
00216                     approxdif = dist;
00217                     approxsol = motion;
00218                 }
00219             }
00220         }
00221     }
00222 
00223     bool solved = false;
00224     bool approximate = false;
00225     if (solution == NULL)
00226     {
00227         solution = approxsol;
00228         approximate = true;
00229     }
00230 
00231     if (solution != NULL)
00232     {
00233         lastGoalMotion_ = solution;
00234 
00235         /* construct the solution path */
00236         std::vector<Motion*> mpath;
00237         while (solution != NULL)
00238         {
00239             mpath.push_back(solution);
00240             solution = solution->parent;
00241         }
00242 
00243         /* set the solution path */
00244         PathControl *path = new PathControl(si_);
00245         for (int i = mpath.size() - 1 ; i >= 0 ; --i)
00246             if (mpath[i]->parent)
00247                 path->append(mpath[i]->state, mpath[i]->control, mpath[i]->steps * siC_->getPropagationStepSize());
00248             else
00249                 path->append(mpath[i]->state);
00250         solved = true;
00251         pdef_->addSolutionPath(base::PathPtr(path), approximate, approxdif, getName());
00252     }
00253 
00254     if (rmotion->state)
00255         si_->freeState(rmotion->state);
00256     if (rmotion->control)
00257         siC_->freeControl(rmotion->control);
00258     delete rmotion;
00259     si_->freeState(xstate);
00260 
00261     OMPL_INFORM("%s: Created %u states", getName().c_str(), nn_->size());
00262 
00263     return base::PlannerStatus(solved, approximate);
00264 }
00265 
00266 void ompl::control::RRT::getPlannerData(base::PlannerData &data) const
00267 {
00268     Planner::getPlannerData(data);
00269 
00270     std::vector<Motion*> motions;
00271     if (nn_)
00272         nn_->list(motions);
00273 
00274     double delta = siC_->getPropagationStepSize();
00275 
00276     if (lastGoalMotion_)
00277         data.addGoalVertex(base::PlannerDataVertex(lastGoalMotion_->state));
00278 
00279     for (unsigned int i = 0 ; i < motions.size() ; ++i)
00280     {
00281         const Motion *m = motions[i];
00282         if (m->parent)
00283         {
00284             if (data.hasControls())
00285                 data.addEdge(base::PlannerDataVertex(m->parent->state),
00286                              base::PlannerDataVertex(m->state),
00287                              control::PlannerDataEdgeControl(m->control, m->steps * delta));
00288             else
00289                 data.addEdge(base::PlannerDataVertex(m->parent->state),
00290                              base::PlannerDataVertex(m->state));
00291         }
00292         else
00293             data.addStartVertex(base::PlannerDataVertex(m->state));
00294     }
00295 }
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Defines