A-LOAM算法完全注释

# A-LOAM ## Advanced implementation of LOAM A-LOAM is an Advanced implementation of LOAM (J. Zhang and S. Singh. LOAM: Lidar Odometry and Mapping in Real-time), which uses Eigen and Ceres Solver to simplify code structure. This code is modified from LOAM and [LOAM_NOTED](https://github.com/cuitaixiang/LOAM_NOTED). This code is clean and simple without complicated mathematical derivation and redundant operations. It is a good learning material for SLAM beginners. <img src="https://github.com/HKUST-Aerial-Robotics/A-LOAM/blob/devel/picture/kitti.png" width = 55% height = 55%/> **Modifier:** [Tong Qin](http://www.qintonguav.com), [Shaozu Cao](https://github.com/shaozu) ## 1. Prerequisites ### 1.1 **Ubuntu** and **ROS** Ubuntu 64-bit 16.04 or 18.04. ROS Kinetic or Melodic. [ROS Installation](http://wiki.ros.org/ROS/Installation) ### 1.2. **Ceres Solver** Follow [Ceres Installation](http://ceres-solver.org/installation.html). ### 1.3. **PCL** Follow [PCL Installation](http://www.pointclouds.org/downloads/linux.html). ## 2. Build A-LOAM Clone the repository and catkin_make: ``` cd ~/catkin_ws/src git clone https://github.com/HKUST-Aerial-Robotics/A-LOAM.git cd ../ catkin_make source ~/catkin_ws/devel/setup.bash ``` ## 3. Velodyne VLP-16 Example Download [NSH indoor outdoor](https://drive.google.com/file/d/1s05tBQOLNEDDurlg48KiUWxCp-YqYyGH/view) to YOUR_DATASET_FOLDER. ``` roslaunch aloam_velodyne aloam_velodyne_VLP_16.launch rosbag play YOUR_DATASET_FOLDER/nsh_indoor_outdoor.bag ``` ## 4. KITTI Example (Velodyne HDL-64) Download [KITTI Odometry dataset](http://www.cvlibs.net/datasets/kitti/eval_odometry.php) to YOUR_DATASET_FOLDER and set the `dataset_folder` and `sequence_number` parameters in `kitti_helper.launch` file. Note you also convert KITTI dataset to bag file for easy use by setting proper parameters in `kitti_helper.launch`. ``` roslaunch aloam_velodyne aloam_velodyne_HDL_64.launch roslaunch aloam_velodyne kitti_helper.launch ``` <img src="https://github.com/HKUST-Aerial-Robotics/A-LOAM/blob/devel/picture/kitti_gif.gif" width = 720 height = 351 /> ## 5. Docker Support To further facilitate the building process, we add docker in our code. Docker environment is like a sandbox, thus makes our code environment-independent. To run with docker, first make sure [ros](http://wiki.ros.org/ROS/Installation) and [docker](https://docs.docker.com/install/linux/docker-ce/ubuntu/) are installed on your machine. Then add your account to `docker` group by `sudo usermod -aG docker $YOUR_USER_NAME`. **Relaunch the terminal or logout and re-login if you get `Permission denied` error**, type: ``` cd ~/catkin_ws/src/A-LOAM/docker make build ``` The build process may take a while depends on your machine. After that, run `./run.sh 16` or `./run.sh 64` to launch A-LOAM, then you should be able to see the result. ## 6.Acknowledgements Thanks for LOAM(J. Zhang and S. Singh. LOAM: Lidar Odometry and Mapping in Real-time) and [LOAM_NOTED](https://github.com/cuitaixiang/LOAM_NOTED).