FAST-LIO-Localization-SC-QN

• This repository is a map-based localization implementation combining FAST-LIO2 as an odometry with Quatro and Nano-GICP module as a map matching method, and with ScanContext as a loop candidate detection method
  • Quatro - fast, accurate and robust global registration which provides great initial guess of transform
  • Quatro module - Quatro as a module, can be easily used in other packages
  • Nano-GICP module - fast ICP combining FastGICP + NanoFLANN
  • ScanContext - a global descriptor for LiDAR point cloud, here it is used as loop candidate pair detection
• Note: similar repositories already exist
  • FAST_LIO_LOCALIZATION: FAST-LIO2 + Open3D's ICP
  • FAST-LIO-Localization-QN: FAST-LIO2 + Quatro + Nano-GICP
• Note2: main code is modularized and hence can be combined with any other LIO / LO
• Note3: this repo is to apply Quatro in localization. Quatro can be worked in scan-to-scan matching or submap-to-submap matching but not scan-to-submap, i.e., the numbers of pointclouds to be matched should be similar.
• Note4: saved map file is needed. The map should be in .bag format. This .bag files can be built with FAST-LIO-SAM-QN and FAST-LIO-SAM

Video clip - https://youtu.be/MQ8XxRY472Y

Main difference between FAST-LIO-Localization-QN and FAST-LIO-Localization-SC-QN

• FAST-LIO-Localization-QN sets loop candidate pair as (current keyframe, the closest and old enough keyframe saved in the map data)
• FAST-LIO-Localization-SC-QN gets loop candidate pair from ScanContext

Dependencies

• C++ >= 17, OpenMP >= 4.5, CMake >= 3.10.0, Eigen >= 3.2, Boost >= 1.54
• ROS
• Teaser++

  git clone https://github.com/MIT-SPARK/TEASER-plusplus.git
  cd TEASER-plusplus && mkdir build && cd build
  cmake .. -DENABLE_DIAGNOSTIC_PRINT=OFF
  sudo make install -j16
  sudo ldconfig

• tbb (is used for faster Quatro)

  sudo apt install libtbb-dev

How to build and use

• Get the code and then build the main code.

  cd ~/your_workspace/src
  git clone https://github.com/engcang/FAST-LIO-Localization-SC-QN --recursive
  
  cd ~/your_workspace
  # nano_gicp, quatro first
  catkin build nano_gicp -DCMAKE_BUILD_TYPE=Release
  # Note the option!
  catkin build quatro -DCMAKE_BUILD_TYPE=Release -DQUATRO_TBB=ON
  catkin build -DCMAKE_BUILD_TYPE=Release
  . devel/setup.bash

• Then run

  roslaunch fast_lio_localization_sc_qn run.launch lidar:=ouster
  roslaunch fast_lio_localization_sc_qn run.launch lidar:=velodyne
  roslaunch fast_lio_localization_sc_qn run.launch lidar:=livox

• Change config files in
  • third_party/FAST_LIO/config
  • fast_lio_localization_sc_qn/config

Structure

• odom_pcd_cb
  • pub realtime pose in corrected frame
  • keyframe detection -> if keyframe, add to pose graph + save to keyframe queue
• matching_timer_func
  • process a saved keyframe
    • detect map match -> if matched, correct TF
• vis_timer_func
  • visualize all