SimpleDirectedControlSampler.cpp
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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 control.
Definition: Control.h:111
Definition of an abstract state.
Definition: State.h:113
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...
Abstract definition of a directed control sampler. Motion planners that need to sample controls that ...
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...