An SE(2) state space where distance is measured by the length of Dubins curves. Note that this Dubins distance is not a proper distance metric, so nearest neighbor methods that rely on distance() being a metric (such ompl::NearestNeighborsGNAT) will not always return the true nearest neighbors or get stuck in an infinite loop. This means that if you use any of the RRT-based planners (which use GNAT by default), you need to do the following: More...
#include <DubinsStateSpace.h>
Classes | |
class | DubinsPath |
Complete description of a Dubins path. More... | |
Public Types | |
enum | DubinsPathSegmentType { DUBINS_LEFT = 0, DUBINS_STRAIGHT = 1, DUBINS_RIGHT = 2 } |
The Dubins path segment type. | |
Public Member Functions | |
DubinsStateSpace (double turningRadius=1.0, bool isSymmetric=false) | |
virtual double | distance (const State *state1, const State *state2) const |
Computes distance between two states. This function satisfies the properties of a metric and its return value will always be between 0 and getMaximumExtent() | |
virtual void | interpolate (const State *from, const State *to, const double t, State *state) const |
Computes the state that lies at time t in [0, 1] on the segment that connects from state to to state. The memory location of state is not required to be different from the memory of either from or to. | |
virtual void | interpolate (const State *from, const State *to, const double t, bool &firstTime, DubinsPath &path, State *state) const |
virtual void | sanityChecks (void) const |
Convenience function that allows derived state spaces to choose which checks should pass (see SanityChecks flags) and how strict the checks are. This just calls sanityChecks() with some default arguments. | |
DubinsPath | dubins (const State *state1, const State *state2) const |
Return the shortest Dubins path from SE(2) state state1 to SE(2) state state2. | |
Static Public Attributes | |
static const DubinsPathSegmentType | dubinsPathType [6][3] |
Dubins path types. | |
Protected Member Functions | |
virtual void | interpolate (const State *from, const DubinsPath &path, const double t, State *state) const |
Protected Attributes | |
double | rho_ |
Turning radius. | |
bool | isSymmetric_ |
Whether the distance is "symmetrized". |
An SE(2) state space where distance is measured by the length of Dubins curves. Note that this Dubins distance is not a proper distance metric, so nearest neighbor methods that rely on distance() being a metric (such ompl::NearestNeighborsGNAT) will not always return the true nearest neighbors or get stuck in an infinite loop. This means that if you use any of the RRT-based planners (which use GNAT by default), you need to do the following:
ob::StateSpacePtr stateSpace(new ob::DubinsStateSpace); og::SimpleSetup setup(stateSpace); og::RRTConnect* planner = new og::RRTConnect(setup.getSpaceInformation()); planner->setNearestNeighbors<ompl::NearestNeighborsSqrtApprox>(); setup.setPlanner(ompl::base::PlannerPtr(planner));
The notation and solutions in the code are taken from:
A.M. Shkel and V. Lumelsky, “Classification of the Dubins set,” Robotics and Autonomous Systems, 34(4):179-202, 2001. DOI: 10.1016/S0921-8890(00)00127-5
The classification scheme described there is not actually used, since it only applies to “long” paths.
Definition at line 72 of file DubinsStateSpace.h.
const ompl::base::DubinsStateSpace::DubinsPathSegmentType ompl::base::DubinsStateSpace::dubinsPathType [static] |
{ { DUBINS_LEFT, DUBINS_STRAIGHT, DUBINS_LEFT }, { DUBINS_RIGHT, DUBINS_STRAIGHT, DUBINS_RIGHT }, { DUBINS_RIGHT, DUBINS_STRAIGHT, DUBINS_LEFT }, { DUBINS_LEFT, DUBINS_STRAIGHT, DUBINS_RIGHT }, { DUBINS_RIGHT, DUBINS_LEFT, DUBINS_RIGHT }, { DUBINS_LEFT, DUBINS_RIGHT, DUBINS_LEFT } }
Dubins path types.
Definition at line 79 of file DubinsStateSpace.h.
bool ompl::base::DubinsStateSpace::isSymmetric_ [protected] |
Whether the distance is "symmetrized".
If true the distance from state s1 to state s2 is the same as the distance from s2 to s1. This is done by taking the minimum length of the Dubins curves that connect s1 to s2 and s2 to s1. If isSymmetric_ is true, then the distance no longer satisfies the triangle inequality.
Definition at line 148 of file DubinsStateSpace.h.