基于软分配SIFT特征的回环检测算法  

Loop closure detection algorithm based on soft assignment SIFT features

作　　者：孙金风[1,2] 袁逸钊 黄斌 杨智勇 Sun Jinfeng;Yuan Yizhao;Huang Bin;Yang Zhiyong(School of Mechanical Engineering,Hubei University of Technology,Wuhan 430068,China;Hubei Key Laboratory of Modern Manufacturing Quantity Engineering,Wuhan 430068,China)

机构地区：[1]湖北工业大学机械工程学院,武汉430068 [2]现代制造质量工程湖北省重点实验室,武汉430068

出　　处：《计算机应用研究》2023年第7期2101-2105,共5页Application Research of Computers

基　　金：国家自然科学基金项目(51907055);湖北省教育厅中青年人才项目(Q20191404)。

摘　　要：回环检测能够消除视觉SLAM的累积误差,对SLAM系统意义重大。其中,应用较广泛的视觉词袋模型算法存在着视觉单词同一性和歧义性问题,影响了回环检测效果。为改善这些问题并提高回环检测效果,提出了一种基于软分配SIFT(scale-invariant feature transform)特征的回环检测算法。该算法将图像提取出的SIFT特征点分配到欧氏距离最近的几个单词上,并根据距离排序加权,剔除距离单词较远的特征点,生成更具区分性的描述子,并且在筛选候选项时,加入相同单词特征点占比以及单词偏移稳定性约束,筛选出少量候选项。实验结果中,该算法相较于传统视觉词袋模型以及近些年的几种回环检测算法,在三种数据集中的100%准确率下的召回率有所提升,图像平均查询时间在40 ms左右。结果表明,该算法对回环检测效果有一定提升,并且保证了实时性。Loop closure detection can eliminate the accumulated error of visual SLAM,which is of great significance to the SLAM system.Among them,the widely used visual bag-of-word model algorithm has the problem of visual word identity and ambiguity,which affects the loop closure detection effect.To improve these problems and loop back detection effect,this paper proposed a loop closure detection algorithm based on soft-assigned SIFT features.The algorithm allocated the SIFT feature points extracted from the image to several words with the closest Euclidean distance,according to the distance sorting and weighting,and removed the feature points that were far away from the words to generate more discriminating descriptors.In addition,when filtering candidates,the algorithm added the proportion constraint of the same word feature points and the stability constraint of word shift to filter out a few candidates.In the experimental results,the algorithm compared with the traditional visual bag-of-words model and several loop closure detection algorithms in recent years,the recall rate at 100%accuracy rate improved under three data sets,and the average image query time was about 40 ms.The results show that the algorithm can improve the loop detection effect and ensure the real-time performance.

关 键 词：视觉SLAM 视觉词袋模型 回环检测 软分配 SIFT 

分 类 号：TP242[自动化与计算机技术—检测技术与自动化装置]