Computer Engineering and Applications ›› 2024, Vol. 60 ›› Issue (20): 180-188.DOI: 10.3778/j.issn.1002-8331.2307-0114

• Graphics and Image Processing • Previous Articles     Next Articles

Visual SLAM Loop Closure Algorithm Based on Semantic and Geometric Consistency

ZHANG Gan, ZHOU Fei, ZHANG Kuo, LI Jiahui   

  1. School of Communication and Information Engineering, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
  • Online:2024-10-15 Published:2024-10-15

基于语义和几何一致性的视觉SLAM回环检测算法

张干,周非,张阔,李嘉辉   

  1. 重庆邮电大学 通信与信息工程学院,重庆 400065

Abstract: Loop closure is the key to eliminate the cumulative error in simultaneous localization and mapping (SLAM) system. When the illumination conditions or the viewing angle change greatly, the traditional appearance-based loop closure methods often fail. Aiming at this situation, an object-level loop closure method is proposed based on ORBSLAM2 framework. Firstly, semantic information obtained by object detection and the feature point information are used to construct object-level semantic map. Then semantic map is abstracted into topological map and landmarks into nodes, node information is described by color histogram, and combined geometric relationship between nodes, a graph matching method is proposed to realize loop detection based on semantic and geometric consistency constraints. When a loop is detected, the loop is corrected by object alignment. Finally, experiments are carried out on the published TUM and USTC data sets, and the results show that the accuracy of the proposed system is 49.58% higher than that of ORBSLAM2 on average, and the constructed semantic map shows a good positioning effect.

Key words: visual simultaneous localization and mapping, loop detection, color histogram, geometric consistency, loop correction

摘要: 回环检测是消除同时定位与地图构建(simultaneous localization and mapping,SLAM)系统中累计误差的关键所在,在光照条件或视角变化较大的情况下,传统的基于外观的回环检测方法往往失效。针对这种情况,在ORBSLAM2的框架基础上提出一种物体级的回环检测方法。利用目标检测获得的语义信息和特征点信息构建物体级语义地图。将语义地图抽象成拓扑图并将地标抽象成节点,用颜色直方图描述节点信息,结合节点间的几何关系,基于语义和几何一致性约束,提出一种图匹配方法实现回环检测。当检测到回环时,通过物体对齐的方式进行回环校正。在公开的TUM和USTC数据集上进行实验,结果表明提出的系统精度较ORBSLAM2平均提高了49.58%,并且构建的语义地图显示出良好的定位效果。

关键词: 视觉同时定位与地图构建, 回环检测, 颜色直方图, 几何一致性, 回环校正