SaD-SLAM: A Visual SLAM Based on Semantic and Depth Information

Simultaneous Localization and Mapping (SLAM) is considered significant for intelligent mobile robot autonomous pathfinding. Over the past years, many successful SLAM systems have been developed and works satisfactorily in static environments. However, in some dynamic scenes with moving objects, the camera pose estimation error would be unacceptable, or the systems even lose their locations. In this paper, we present SaD-SLAM, a visual SLAM system that, building on ORB-SLAM2, achieves excellent performance in dynamic environments. With the help of semantic and depth information, we find out feature points that belong to movable objects. And we detect whether those feature points are keeping still at the moment. To make the system perform accurately and robustly in dynamic scenes, we use both feature points extracted from static objects and static feature points derived from movable objects to finetune the camera pose estimation. We evaluate our algorithm in TUM RGB-D datasets. The results demonstrate the absolute trajectory accuracy of SaD-SLAM can be improved significantly compared with the original ORB-SLAM2. We also compare our algorithm with DynaSLAM and DS-SLAM, which are designed to fit dynamic scenes.