SLAM	Simultaneous localization and mapping
IMU	Inertial measurement unit
ORB	Oriented FAST and rotated BRIEF
LIO	Lidar-inertial odometry
VIO	Visual-inertial odometry
LK	Lucas-Kanade
LIS	Lidar-inertial system
VIS	Visual-inertial system
ROS	Robot operating system
STD	Standard deviation
RMSE	Root mean square error