[mrpt-graphslam]

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Detailed Description

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Library mrpt-graphslam

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Graph-SLAM: See the namespace mrpt::graphslam

Classes
struct	mrpt::graphslam::graphslam_traits
	Auxiliary traits template for use among graph-slam problems to make life easier with these complicated, long data type names. More...
struct	mrpt::graphslam::TResultInfoSpaLevMarq
	Output information for mrpt::graphslam::optimize_graph_spa_levmarq() More...
Namespaces
namespace	mrpt::graphslam
	SLAM methods related to graphs of pose constraints.
Functions
template<class GRAPH_T >
void	mrpt::graphslam::optimize_graph_spa_levmarq (GRAPH_T &graph, TResultInfoSpaLevMarq &out_info, const std::set< mrpt::utils::TNodeID > *in_nodes_to_optimize=NULL, const mrpt::utils::TParametersDouble &extra_params=mrpt::utils::TParametersDouble(), typename graphslam_traits< GRAPH_T >::TFunctorFeedback functor_feedback=NULL)
	Optimize a graph of pose constraints using the Sparse Pose Adjustment (SPA) sparse representation and a Levenberg-Marquartd optimizer.

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Function Documentation

template<class GRAPH_T >

void mrpt::graphslam::optimize_graph_spa_levmarq	(	GRAPH_T &	graph,
		TResultInfoSpaLevMarq &	out_info,
		const std::set< mrpt::utils::TNodeID > *	in_nodes_to_optimize = NULL,
		const mrpt::utils::TParametersDouble &	extra_params = mrpt::utils::TParametersDouble(),
		typename graphslam_traits< GRAPH_T >::TFunctorFeedback	functor_feedback = NULL
	)

Optimize a graph of pose constraints using the Sparse Pose Adjustment (SPA) sparse representation and a Levenberg-Marquartd optimizer.

This method works for all types of graphs derived from CNetworkOfPoses (see its reference mrpt::graphs::CNetworkOfPoses for the list). The input data are all the pose constraints in graph (graph.edges), and the gross first estimations of the "global" pose coordinates (in graph.nodes).

Note that these first coordinates can be obtained with mrpt::graphs::CNetworkOfPoses::dijkstra_nodes_estimate().

The method implemented in this file is based on this work:

• "Efficient Sparse Pose Adjustment for 2D Mapping", Kurt Konolige et al., 2010. , but generalized for not only 2D but 2D and 3D poses, and using on-manifold optimization.

Parameters:

[in,out]	graph	The input edges and output poses.
[out]	out_info	Some basic output information on the process.
[in]	nodes_to_optimize	The list of nodes whose global poses are to be optimized. If NULL (default), all the node IDs are optimized (but that marked as root in the graph).
[in]	extra_params	Optional parameters, see below.
[in]	functor_feedback	Optional: a pointer to a user function can be set here to be called on each LM loop iteration (eg to refresh the current state and error, refresh a GUI, etc.)

List of optional parameters by name in "extra_params":

• "verbose": (default=0) If !=0, produce verbose ouput.
• "max_iterations": (default=100) Maximum number of Lev-Marq. iterations.
• "scale_hessian": (default=0.1) Multiplies the Hessian matrix by this scalar (may improve convergence speed).
• "initial_lambda": (default=0) <=0 means auto guess, otherwise, initial lambda value for the lev-marq algorithm.
• "tau": (default=1e-3) Initial tau value for the lev-marq algorithm.
• "e1": (default=1e-6) Lev-marq algorithm iteration stopping criterion #1: |gradient| < e1
• "e2": (default=1e-6) Lev-marq algorithm iteration stopping criterion #2: |delta_incr| < e2*(x_norm+e2)

Note:

The following graph types are supported: mrpt::graphs::CNetworkOfPoses2D, mrpt::graphs::CNetworkOfPoses3D, mrpt::graphs::CNetworkOfPoses2DInf, mrpt::graphs::CNetworkOfPoses3DInf

Template Parameters:

GRAPH_T

Normally a mrpt::graphs::CNetworkOfPoses<EDGE_TYPE,MAPS_IMPLEMENTATION>. Users won't have to write this template argument by hand, since the compiler will auto-fit it depending on the type of the graph object.

See also:

The example "graph_slam_demo"

Note:

Implementation can be found in file levmarq_impl.h

Definition at line 73 of file levmarq.h.

References MRPT_START, mrpt::utils::CTimeLogger::enter(), mrpt::utils::CTimeLogger::leave(), ASSERT_ABOVE_, VERBOSE_PREFIX, ASSERTDEBMSG_, ASSERTDEB_, mrpt::utils::find_in_vector(), ASSERT_EQUAL_, mrpt::system::os::memcpy(), norm_inf(), mrpt::math::UNINITIALIZED_MATRIX, begin(), mrpt::utils::keep_max(), mrpt::math::CSparseMatrix::insert_entry_fast(), mrpt::math::CSparseMatrix::insert_submatrix(), mrpt::math::CSparseMatrix::compressFromTriplet(), mrpt::math::norm(), mrpt::utils::square(), mrpt::format(), mrpt::poses::UNINITIALIZED_POSE, Eigen::Matrix::swap(), mrpt::graphslam::TResultInfoSpaLevMarq::num_iters, mrpt::graphslam::TResultInfoSpaLevMarq::final_total_sq_error, and MRPT_END.