sync_lidartag_apriltag

Overview

This is a synchronization package for LiDARTags and AprilTags. As the LiDAR and camera data streams arrive, they are synchronized (synchronization node), examined for fiducial markers (LiDARTags and AprilTags), and checked for false positives (tag-pairing node). The relevant information is saved as ROS bagfiles from alignment_msgs for post-processing in another package. For LiDAR-Camera extrinsic calibration, we use target vertices and image corners as our features.

• Authors: Bruce JK Huang, Chenxi Feng
• Maintainer: Bruce JK Huang, brucejkh[at]gmail.com
• Affiliation: The Biped Lab, the University of Michigan

This package has been tested under MATLAB2019a and Ubuntu 16.04.

Required packages

Please download alignment_msgs from here. Please download LiDARTag from here.
Please download LiDARTag_msgs from here.
Please download AprilTag from here.
Please download AprilTag_msgs from here.

Input/Output

Input: LiDAR piont clouds and camera images publish via ROS.
Output: alignment_msgs containing relevant information such as AprilTag corners and LiDARTag target points.

How it works

Comming by 4/5/2020

Usage

This package contains three launch files.

1. The sync_cam_lidar launch file will run the data synchronization node, launch the LiDARTag and AprilTag nodes.
2. The alignment_node_only launch file will run the tag pairing node, which detect false positives of the LiDARTags and AprilTags.
3. The sync_node_only launch file will only run the data synchronization node, which synchronizes LiDAR point clouds and camera images.

Usage for automatic calibration

To compete the fron-end of the pipeline of the automatic calibration, the sync_cam_lidar launch file should be ran first, and then run the alignment_node_only launch file to run the tag pairing node.

Citations

1. Jiunn-Kai Huang, Chenxi Feng, Madhav Achar, Maani Ghaffari, and Jessy W. Grizzle, "Global Unifying Intrinsic Calibration for Spinning and Solid-State LiDARs" (arXiv)

@article{huang2020global,
  title={Global Unifying Intrinsic Calibration for Spinning and Solid-State LiDARs},
  author={Huang, Jiunn-Kai and Feng, Chenxi and Achar, Madhav and Ghaffari, Maani and Grizzle, Jessy W},
  journal={arXiv preprint arXiv:2012.03321},
  year={2020}
}

2. Jiunn-Kai Huang and J. Grizzle, "Improvements to Target-Based 3D LiDAR to Camera Calibration" (PDF)(arXiv)

@article{huang2020improvements,
  author={J. {Huang} and J. W. {Grizzle}},
  journal={IEEE Access}, 
  title={Improvements to Target-Based 3D LiDAR to Camera Calibration}, 
  year={2020},
  volume={8},
  number={},
  pages={134101-134110},}

3. Jiunn-Kai Huang, Maani Ghaffari, Ross Hartley, Lu Gan, Ryan M. Eustice, and Jessy W. Grizzle, "LiDARTag: A Real-Time Fiducial Tag using Point Clouds" (PDF)(arXiv)

@article{huang2019lidartag,
  title={LiDARTag: A Real-Time Fiducial Tag using Point Clouds},
  author={Huang, Jiunn-Kai and Ghaffari, Maani and Hartley, Ross and Gan, Lu and Eustice, Ryan M and Grizzle, Jessy W},
  journal={arXiv preprint arXiv:1908.10349},
  year={2019}
}