PlanarManipulatorIKGoal.h
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34 
35 /* Author: Ryan Luna */
36 
37 #ifndef PLANAR_MANIPULATOR_IK_GOAL_H_
38 #define PLANAR_MANIPULATOR_IK_GOAL_H_
39 
40 #include <ompl/base/goals/GoalLazySamples.h>
41 #include <eigen3/Eigen/Dense>
42 #include "PlanarManipulator.h"
43 #include "PlanarManipulatorStateSpace.h"
44 
45 #include <boost/math/constants/constants.hpp>
46 
47 #ifndef PI
48 #define PI boost::math::constants::pi<double>()
49 #define TWOPI boost::math::constants::two_pi<double>()
50 #endif
51 
52 // A goal that allows for specification of position (and optionally, the
53 // orientation) for the end effector of a planar manipulator.
54 // Uses GoalLazySamples to sample valid IK positions
56 {
57 public:
58  // If fixedOrientation is false, the orientation in the goalPose is not
59  // considered (a random orientation will be sampled).
60  PlanarManipulatorIKGoal(const ompl::base::SpaceInformationPtr &si, const Eigen::Affine2d &goalPose,
61  const PlanarManipulator *manipulator, bool fixedOrientation = true)
63  si, [this](const ompl::base::GoalLazySamples *, ompl::base::State *st) { return sampleGoalThread(st); },
64  true)
65  , goalPose_(goalPose)
66  , manipulator_(manipulator)
67  , fixedOrientation_(fixedOrientation)
68  {
69  }
70 
71  virtual double distanceGoal(const ompl::base::State *st) const
72  {
73  const double *angles = st->as<PlanarManipulatorStateSpace::StateType>()->values;
74 
75  // Figure out where the end effector is
76  Eigen::Affine2d eeFrame;
77  manipulator_->FK(angles, eeFrame);
78 
79  double cartesianDist = (eeFrame.translation() - goalPose_.translation()).norm();
80 
81  // Orientation does not matter
82  if (!fixedOrientation_)
83  return cartesianDist;
84 
85  double eeRot = acos(eeFrame.matrix()(0, 0));
86  double goalRot = acos(goalPose_.matrix()(0, 0));
87  double angleDiff = fabs(goalRot - eeRot);
88 
89  // return the translational and rotational differences
90  return cartesianDist + angleDiff;
91  }
92 
93 protected:
94  bool sampleGoalThread(ompl::base::State *st) const
95  {
96  std::vector<double> seed(manipulator_->getNumLinks());
97  std::vector<double> soln(manipulator_->getNumLinks());
98 
99  bool good = false;
100  unsigned int maxTries = 1000;
101  unsigned int tries = 0;
102  do
103  {
104  // random seed
105  for (size_t i = 0; i < seed.size(); ++i)
106  seed[i] = rng_.uniformReal(-PI, PI);
107 
108  for (size_t i = 0; i < 10 && !good; ++i)
109  {
110  Eigen::Affine2d pose(goalPose_);
111  if (!fixedOrientation_)
112  {
113  // Sample the orientation if it does not matter
114  pose.rotate(rng_.uniformReal(-PI, PI));
115  }
116 
117  if (manipulator_->FABRIK(soln, seed, pose))
118  {
119  // copy values into state
120  memcpy(st->as<PlanarManipulatorStateSpace::StateType>()->values, &soln[0],
121  soln.size() * sizeof(double));
122  // GoalLazySamples will check validity
123  good = true;
124  }
125  tries++;
126  }
127 
128  } while (!good && tries < maxTries);
129 
130  return good;
131  }
132 
133  Eigen::Affine2d goalPose_;
134  const PlanarManipulator *manipulator_;
135  bool fixedOrientation_;
136  mutable ompl::RNG rng_;
137 };
138 
139 #endif
virtual double distanceGoal(const ompl::base::State *st) const
Compute the distance to the goal (heuristic). This function is the one used in computing the distance...
Random number generation. An instance of this class cannot be used by multiple threads at once (membe...
Definition: RandomNumbers.h:58
double uniformReal(double lower_bound, double upper_bound)
Generate a random real within given bounds: [lower_bound, upper_bound)
Definition: RandomNumbers.h:73
Definition of a goal region that can be sampled, but the sampling process can be slow....
double * values
The value of the actual vector in Rn
A shared pointer wrapper for ompl::base::SpaceInformation.
Definition of an abstract state.
Definition: State.h:50
const T * as() const
Cast this instance to a desired type.
Definition: State.h:66