ORB-SLAM3: An Accurate Open-Source Library for Visual, Visual–Inertial, and Multimap

Date: 2021
Journal: T-RO

3. System Overview

1) Atlas

Multimap representation composed of a set of disconnected maps

Active map is where tracking threads localizes incoming frames, the others are nonactive maps

2) Tracking thread

Compute pose of current frame with respect to active map in real time

If tracking is lost, tries to relocalize in all the atlas maps

3) Local mapping thread

Add keyframes and points to the active map, removes redundant ones, and refines the map using visual or visual-inertial BA

4) Loop and map merging thread

Detect common regions between active map and the whole atlas at keyframe rate

If it belongs to active map, performs loop correction

If not, merge both maps into single one

ORB SLAM 정리
WIP ORB SLAM2 정리
WIP ORB SLAM3 정리