SimpleDirectedControlSampler.cpp
1 /*********************************************************************
2 * Software License Agreement (BSD License)
3 *
4 * Copyright (c) 2011, Willow Garage, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * * Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * * Redistributions in binary form must reproduce the above
14 * copyright notice, this list of conditions and the following
15 * disclaimer in the documentation and/or other materials provided
16 * with the distribution.
17 * * Neither the name of the Willow Garage nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
29 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
31 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32 * POSSIBILITY OF SUCH DAMAGE.
33 *********************************************************************/
34 
35 /* Author: Ioan Sucan */
36 
37 #include "ompl/control/SimpleDirectedControlSampler.h"
38 #include "ompl/control/SpaceInformation.h"
39 
41  : DirectedControlSampler(si), cs_(si->allocControlSampler()), numControlSamples_(k)
42 {
43 }
44 
45 ompl::control::SimpleDirectedControlSampler::~SimpleDirectedControlSampler() = default;
46 
48  base::State *dest)
49 {
50  return getBestControl(control, source, dest, nullptr);
51 }
52 
54  const base::State *source, base::State *dest)
55 {
56  return getBestControl(control, source, dest, previous);
57 }
58 
60  base::State *dest, const Control *previous)
61 {
62  // Sample the first control
63  if (previous != nullptr)
64  cs_->sampleNext(control, previous, source);
65  else
66  cs_->sample(control, source);
67 
68  const unsigned int minDuration = si_->getMinControlDuration();
69  const unsigned int maxDuration = si_->getMaxControlDuration();
70 
71  unsigned int steps = cs_->sampleStepCount(minDuration, maxDuration);
72  // Propagate the first control, and find how far it is from the target state
73  base::State *bestState = si_->allocState();
74  steps = si_->propagateWhileValid(source, control, steps, bestState);
75 
76  if (numControlSamples_ > 1)
77  {
78  Control *tempControl = si_->allocControl();
79  base::State *tempState = si_->allocState();
80  double bestDistance = si_->distance(bestState, dest);
81 
82  // Sample k-1 more controls, and save the control that gets closest to target
83  for (unsigned int i = 1; i < numControlSamples_; ++i)
84  {
85  unsigned int sampleSteps = cs_->sampleStepCount(minDuration, maxDuration);
86  if (previous != nullptr)
87  cs_->sampleNext(tempControl, previous, source);
88  else
89  cs_->sample(tempControl, source);
90 
91  sampleSteps = si_->propagateWhileValid(source, tempControl, sampleSteps, tempState);
92  double tempDistance = si_->distance(tempState, dest);
93  if (tempDistance < bestDistance)
94  {
95  si_->copyState(bestState, tempState);
96  si_->copyControl(control, tempControl);
97  bestDistance = tempDistance;
98  steps = sampleSteps;
99  }
100  }
101 
102  si_->freeState(tempState);
103  si_->freeControl(tempControl);
104  }
105 
106  si_->copyState(dest, bestState);
107  si_->freeState(bestState);
108 
109  return steps;
110 }
Definition of an abstract state.
Definition: State.h:50
Definition of an abstract control.
Definition: Control.h:48
Abstract definition of a directed control sampler. Motion planners that need to sample controls that ...
SimpleDirectedControlSampler(const SpaceInformation *si, unsigned int k=1)
Constructor takes the state space to construct samples for as argument Optionally,...
virtual unsigned int getBestControl(Control *control, const base::State *source, base::State *dest, const Control *previous)
Samples numControlSamples_ controls, and returns the control that brings the system the closest to ta...
unsigned int sampleTo(Control *control, const base::State *source, base::State *dest) override
Sample a control given that it will be applied to state state and the intention is to reach state des...
Space information containing necessary information for planning with controls. setup() needs to be ca...