A-LOAM

Introduction

LOAM is a real-time method for odometry and mapping using range measurements from a 2-axis lidar moving in 6-DOF. It achieves both low-drift and low-computational complexity with- out the need for high accuracy ranging or inertial measurements. The key idea in obtaining this level of performance is the division of the complex problem of simultaneous localization and mapping, which seeks to optimize a large number of variables simultaneously, by two algorithms. One algorithm performs odometry at a high frequency but low fidelity to estimate velocity of the lidar. Another algorithm runs at a frequency of an order of magnitude lower for fine matching and registration of the point cloud. Combination of the two algorithms allows the method to map in real-time. The method has been evaluated by a large set of experiments as well as on the KITTI odometry benchmark. Here are some reference links: code link. paper link.

Image description — Fig. 1. Workflow diagram of LOAM

2 Compilation Process

2.1 Requirement

ubuntu20.04 、ros-noetic、cmake、gcc、g++、opencv、cv-bridge、eigen、pcl1.10、ceres-solver-1.14.0、aloam code、bag。
During the installation of third-party libraries, there may be many version mismatch issues.
Below are just examples of installation.
Please make sure to match the versions, otherwise compilation will have significant problems.
If there are any issues during the appeal process, please search online to resolve them.

install dependence


              sudo apt-get update 

              sudo apt-get install git gcc g++ vim make cmake

install Eigen3


              download Eigen3 

              cd eigen3

              mkdir build && cd build

              cmake ..

              make

              sudo make install

install Ceres


              sudo apt-get install libgoogle-glog-dev libgflags-dev

              sudo apt-get install libatlas-base-dev

              download Ceres 

              mkdir ceres-bin 

              cd ceres-bin 

              cmake ../ceres-solver-1.14.0 

              make  

              sudo make install

2.2 Build 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

if you fail in this step, try to find another computer with clean system or reinstall Ubuntu and ROS

2.3 Run LOAM


            roslaunch aloam_velodyne xxxxx.launch

Evaluation

Platforms	Sequences	Length(m)	ATE
A Handheld Device	Escalator	77.460	3.235
	MCR normal dark	76.499	0.042
	MCR aggressive 6dof light	100.871	0.425
	Parkway loop night	461.049	25.818
	Forest	130.937	0.357
A UGV	Elevator	39.336	X
	Indoor loop	270.674	0.090
	MCR hdr	193.918	0.049
	Street day	2064.475	27.454
	Parkway loop night	461.051	12.501
A QR	Underground	98.312	0.052
	MCR hdr	85.08	0.086
	Forest	108.037	0.129
A UAV	MCR loop light	104.989	LiDARs not supported
A Car	Urban night loop	1807.884	33.893