scan_match_localization.cpp

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/*
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#include <graph_slam/scan_match_localization.h>
#include <pose_graph/utils.h>
#include <pose_graph/transforms.h>

namespace graph_slam
{

namespace gm=geometry_msgs;
namespace ksm=karto_scan_matcher;

using namespace pose_graph;


ScanMatchLocalization::ScanMatchLocalization (const gm::Pose2D& laser_offset, double nbd_size,
                                              const unsigned localizations_per_scan_match) :
  ScanManager(laser_offset), max_link_length_(nbd_size),
  localizations_per_scan_match_(localizations_per_scan_match)
{}

LocalizationState ScanMatchLocalization::nextState (const LocalizationState& state,
                                                    const gm::Pose& fixed_frame_pose, const LaserPtr scan, 
                                                    const pg::PoseGraph& graph, 
                                                    const NodePoseMap& optimized_poses) const
{
  // Set optimized poses during this function
  WithOptimizedPoses opt(this, optimized_poses);
  
  // Initialize matcher if necessary
  if (!matcher_)
    matcher_.reset(new ksm::KartoScanMatcher(*scan, laser_offset_, 0.3, 0.01));
  
  // Identify transform between fixed frame and implicit frame of the optimized poses
  const gm::Pose opt_ref_pose = keyValue(optimized_poses, state.ref_node);
  const Eigen3::Affine3d node_to_opt(poseToWorldTransform(opt_ref_pose));
  const Eigen3::Affine3d fixed_frame_to_node(state.node_to_fixed_frame.inverse());
  const Eigen3::Affine3d fixed_frame_to_opt = node_to_opt*fixed_frame_to_node;
  
  // Initial estimate of current pose in optimized frame
  const gm::Pose init_pose = applyTransform(fixed_frame_to_opt, fixed_frame_pose);
  ROS_DEBUG_STREAM_NAMED ("localization_internal", "Fixed frame pose is " << projectToPose2D(fixed_frame_pose) 
                          << " and optimized frame pose is " << projectToPose2D(init_pose));
  ROS_DEBUG_STREAM_NAMED ("localization_internal", "Fixed frame to opt transform is " <<
                          toString2D(fixed_frame_to_opt));

  // Barycenter
  const gm::Point barycenter_base = computeBarycenterInBaseFrame(scan);
  const gm::Point barycenter_fixed = pointInReferenceFrame(barycenter_base, fixed_frame_pose);
  const gm::Point barycenter_opt = transformPoint(fixed_frame_to_opt, barycenter_fixed);
  ROS_DEBUG_STREAM_NAMED ("localization_internal", "Barycenter in fixed frame is " << barycenter_fixed);

  // Nodes that we'll scan match against
  const NodeSet nbd = nearbyNodes(state.ref_node, barycenter_opt, graph, max_link_length_);
  ROS_DEBUG_STREAM_NAMED ("localization_internal", "Neighborhood is " << toString(nbd));

  if (nbd.size() > 0) {

    static unsigned counter = 0;

    // Do the scan matching
    gm::Pose corrected_pose;
    if (counter++ % localizations_per_scan_match_) {
      corrected_pose = init_pose;
      ROS_DEBUG_NAMED ("localization_internal", "Not scan matching this time");
    }
    else {
      const ksm::ScanMatchResult res = scanMatchNodes(matcher_, init_pose, scan, nbd);
      corrected_pose = convertToPose(res.pose);
      ROS_DEBUG_STREAM_NAMED ("localization_internal", "Scan matching returned pose " << toString(res.pose) << 
                              " with response " << res.response);
    }
  
    // Figure out the new closest node
    Eigen3::Affine3d corrected_fixed_frame_to_opt = transformBetween(fixed_frame_pose, corrected_pose);
    const pg::NodeId closest = closestNode(projectToPose2D(corrected_pose), nbd);
    const gm::Pose closest_pose = keyValue(optimized_poses, closest);
    ROS_DEBUG_STREAM_NAMED ("localization_internal", "Corrected fixed frame to opt transform is " 
                            << toString2D(corrected_fixed_frame_to_opt));

    // Return updated state
    const Eigen3::Affine3d opt_to_closest(poseToWorldTransform(closest_pose).inverse());
    const Eigen3::Affine3d corrected_fixed_frame_to_node=opt_to_closest*corrected_fixed_frame_to_opt;
    const Pose new_local_pose = applyTransform(corrected_fixed_frame_to_node, fixed_frame_pose);
    const Eigen3::Affine3d node_to_fixed_frame(corrected_fixed_frame_to_node.inverse());
    ROS_DEBUG_STREAM_COND_NAMED (closest!=state.ref_node, "localization_switch", "Switching from node " <<
                                 state.ref_node << " to " << closest << "; poses are " <<
                                 toString2D(state.node_frame_pose) << " and " << toString2D(new_local_pose));
    return LocalizationState(closest, node_to_fixed_frame, new_local_pose, scan->header.stamp);
  }
  else {
    ROS_WARN_THROTTLE (3.0, "In localization update, current position had an empty neighborhood, so not updating");
    return state;
  }
}

} // namespace graph_slam