Overview

This a ros package for multi lidar calibration improved qh's previous appearance-based work. Several method are to be implemented:

Dependency List

• PCL 1.8 (http://pointclouds.org/)
• Eigen 3
• Boost
• libpointmatcher (https://github.com/ethz-asl/libpointmatcher)
• Ceres-solver (http://ceres-solver.org/)
• YAML (https://github.com/jbeder/yaml-cpp)

Test on Ubuntu 16.04, ROS Kinetic

Usage

1. Create a yaml file cfg.yaml into a fold, please follow ../data/example/top_tail/cfg.yaml to write
2. Preproces raw pointcloud to keep points with only planes. You can use the below function or CloudCompare software like this:
   rosrun lidar_appearance_calibration calib_preprocess ../data/example/raw/ref.pcd ../data/example/raw/data.pcd ../data/example/raw/ref_filter.pcd ../data/example/raw/data_filter.pcd
   
3. Extract planes from pointcloud
   rosrun lidar_appearance_calibration calib_plane_extraction pcd ../data/example/top_front/cfg.yaml
rostopic pub /contact/icp std_msgs/String "data: ''" rviz -d ../rviz/plane_extraction
4. Visualize and check the extracted plane order
   rosrun pcl_ros pcd_to_pointcloud ../data/example/top_front/plane/ref_planes.pcd 1

rosrun pcl_ros pcd_to_pointcloud ../data/example/top_front/plane/data_planes.pcd 1

rviz -d ../rviz/plane_extraction
   
5. Implement ICP to minimize Plane-to-Plane error
   
   • Auto initialization
     rosrun lidar_appearance_calibration calib_icp ../data/example/top_front/ref_cfg.yaml ../data/example/top_front/data_cfg.yaml a
   • Manual initialization
     rosrun lidar_appearance_calibration calib_icp ../data/example/top_front/ref_cfg.yaml ../data/example/top_front/data_cfg.yaml m
   • Call the program
     rostopic pub /contact/save_plane std_msgs/String "data: ''"
6. Visualize the calibration result
   pcl_viewer ../data/example/top_front/merged_opt.pcd

Result

1. Plane extraction
   
   
2. Pointcloud fusion
   
   
3. Calibration resut
   
   

---

LQH's previous work

1. ICP(point-plane minimizer, libpointmatcher)
2. plane fitting optimization(single shot)
3. auxiliary objects(plane, stick)

JJH's current work (20190103 - now)

1. Automatic plane selection and correspondence matching
   
   • RANSAC
     
   • Order normal
     
2. Find rotation between three pairs of normals
   
3. Minimize point-to-plane error