demos/Koules/KoulesSimulator.h
00001 /*********************************************************************
00002 * Software License Agreement (BSD License)
00003 *
00004 *  Copyright (c) 2013, Rice University
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 Rice University 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: Beck Chen, Mark Moll */
00036 
00037 #ifndef DEMOS_KOULES_SIMULATOR_
00038 #define DEMOS_KOULES_SIMULATOR_
00039 
00040 #include "KoulesConfig.h"
00041 #include <ompl/control/StatePropagator.h>
00042 #include <boost/tuple/tuple.hpp>
00043 #include <boost/tuple/tuple_comparison.hpp>
00044 #include <queue>
00045 
00046 // State propagator for KoulesSetup.
00047 class KoulesSimulator
00048 {
00049 public:
00050     KoulesSimulator(const ompl::control::SpaceInformation* si);
00051 
00052     // A propagate step.
00053     void step(const ompl::base::State *start, const ompl::control::Control* control,
00054         const double t, ompl::base::State *result);
00055 
00056 protected:
00057     // A tuple containing the time and id's of two objects colliding
00058     typedef boost::tuple<double, unsigned int, unsigned int> CollisionEvent;
00059     // A priority queue of events, s.t. the top element is the collision
00060     // that will happen first.
00061     typedef std::priority_queue<CollisionEvent, std::vector<CollisionEvent>,
00062         std::greater<CollisionEvent> > CollisionEventQueue;
00063 
00064     // Compute the collision events based on current positions and velocities.
00065     // Push objects apart if they are slightly overlapping.
00066     void initCollisionEvents(void);
00067     // Return time when i will return with horizontal (dim==0) or vertical
00068     // (dim==1) walls.
00069     double wallCollideEvent(unsigned int i, int dim);
00070     // Compute the collision response velocities when i and j collide.
00071     void elasticCollision(unsigned int i, unsigned int j);
00072     // Compute time if/when i and j will collide. If it happens before
00073     // endTime_, insert a collision event in the queue.
00074     void computeCollisionEvent(unsigned int i, unsigned int j);
00075     // Advance to the system to time t assuming no collision happen
00076     // between time_ and t.
00077     void advance(double t);
00078     // Mark object i as dead. The koules have id's 1,..,numKoules_, while
00079     // the ship has id 0.
00080     void markAsDead(unsigned int i);
00081     // Analytic solution for ship's motion from time 0 to t.
00082     void updateShip(const ompl::control::Control* control, double t);
00083 
00084     // Pointer to Koules' SpaceInformation.
00085     const ompl::control::SpaceInformation* si_;
00086     // Number of dimensions in state space.
00087     unsigned int numDimensions_;
00088     // Number of koules.
00089     unsigned int numKoules_;
00090     // Scratch space holding the current state.
00091     std::vector<double> qcur_;
00092     // Scrath space holding the next state after integration.
00093     std::vector<double> qnext_;
00094     // A vector of flags indicating which objects are dead.
00095     std::vector<bool> dead_;
00096     // The current time in the simulation.
00097     double time_;
00098     // The time to stop the simulation.
00099     double endTime_;
00100     // A queue of collision events.
00101     CollisionEventQueue collisionEvents_;
00102 };
00103 
00104 #endif
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Defines