Although VSLAM/VISLAM has achieved great success,it is still difficult to quantitatively evaluate the localization results of different kinds of SLAM systems from the aspect of augmented reality due to the lack of an ...Although VSLAM/VISLAM has achieved great success,it is still difficult to quantitatively evaluate the localization results of different kinds of SLAM systems from the aspect of augmented reality due to the lack of an appropriate benchmark.For AR applications in practice,a variety of challenging situations(e.g.,fast motion,strong rotation,serious motion blur,dynamic interference)may be easily encountered since a home user may not carefully move the AR device,and the real environment may be quite complex.In addition,the frequency of camera lost should be minimized and the recovery from the failure status should be fast and accurate for good AR experience.Existing SLAM datasets/benchmarks generally only provide the evaluation of pose accuracy and their camera motions are somehow simple and do not fit well the common cases in the mobile AR applications.With the above motivation,we build a new visual-inertial dataset as well as a series of evaluation criteria for AR.We also review the existing monocular VSLAM/VISLAM approaches with detailed analyses and comparisons.Especially,we select 8 representative monocular VSLAM/VISLAM approaches/systems and quantitatively evaluate them on our benchmark.Our dataset,sample code and corresponding evaluation tools are available at the benchmark website http://www.zjucvg.net/eval-vislam/.展开更多
A new method for speeding up the state augment operations involved in the compressed extended Kalman filter-based simultaneous localization and mapping （CEKF-SLAM） algorithm was proposed. State augment usually requi...A new method for speeding up the state augment operations involved in the compressed extended Kalman filter-based simultaneous localization and mapping （CEKF-SLAM） algorithm was proposed. State augment usually requires a fully-updated state eovariance so as to append the information of newly observed landmarks, thus computational volume increases quadratically with the number of landmarks in the whole map. It was proved that state augment can also be achieved by augmenting just one auxiliary coefficient ma- trix. This method can yield identical estimation results as those using EKF-SLAM algorithm, and computa- tional amount grows only linearly with number of increased landmarks in the local map. The efficiency of this quick state augment for CEKF-SLAM algorithm has been validated by a sophisticated simulation project.展开更多
载体定位是实现自动驾驶的关键技术之一,其中基于地图的定位技术具有精度高和鲁棒性强的优点。同步定位与建图(simultaneous localization and mapping,SLAM)技术是针对未知环境地图构建的典型方法,在地铁隧道场景中,传统SLAM算法易因...载体定位是实现自动驾驶的关键技术之一,其中基于地图的定位技术具有精度高和鲁棒性强的优点。同步定位与建图(simultaneous localization and mapping,SLAM)技术是针对未知环境地图构建的典型方法,在地铁隧道场景中,传统SLAM算法易因几何结构的严重退化而导致建图失败。针对此问题,文章提出一种基于点云强度特征的建图算法。其首先进行基于点云强度的特征点云提取,并根据广义迭代最近点算法完成高强度特征点云残差构建,以增加运动约束;其次,基于位姿图优化融合激光雷达数据与惯性测量单元数据,完成位姿优化与地图构建;最后,使用地铁隧道离线数据进行算法验证,结果显示,采用该方法成功构建了地铁全线的点云地图,地图无明显漂移,并采用隧道壁上固定安装距离的标识物体进行地图精度评估,所建地图平均偏差小于0.2m,验证了所提算法的有效性与鲁棒性。展开更多
Simultaneous localization and mapping(SLAM)has attracted considerable research interest from the robotics and computer-vision communities for>30 years.With steady and progressive efforts being made,modern SLAM syst...Simultaneous localization and mapping(SLAM)has attracted considerable research interest from the robotics and computer-vision communities for>30 years.With steady and progressive efforts being made,modern SLAM systems allow robust and online applications in real-world scenes.We examined the evolution of this powerful perception tool in detail and noticed that the insights concerning incremental computation and temporal guidance are persistently retained.Herein,we denote this temporal continuity as a flow basis and present for the first time a survey that specifically focuses on the flow-based nature,ranging from geometric computation to the emerging learning techniques.We start by reviewing two essential stages for geometric computation,presenting the de facto standard pipeline and problem formulation,along with the utilization of temporal cues.The recently emerging techniques are then summarized,covering a wide range of areas,such as learning techniques,sensor fusion,and continuous time trajectory modeling.This survey aims at arousing public attention on how robust SLAM systems benefit from a continuously observing nature,as well as the topics worthy of further investigation for better utilizing the temporal cues.展开更多
目的研究增强现实(augmented reality,AR)航天飞行训练空间定位问题。方法采用同步定位与建图(simultaneous localization and mapping,SLAM)技术提出增强现实航天飞行训练系统框架;构建包含图像获取,特征提取描述与匹配、相机位姿估计...目的研究增强现实(augmented reality,AR)航天飞行训练空间定位问题。方法采用同步定位与建图(simultaneous localization and mapping,SLAM)技术提出增强现实航天飞行训练系统框架;构建包含图像获取,特征提取描述与匹配、相机位姿估计,图优化以闭环检测及构图的空间定位算法,并对算法进行实验验证。结果通过与高精度全站仪数据比较,验证了算法的测量精度和有效性。结论本文方法能够以主动方式向航天员提供飞行训练引导信息,减轻航天飞行训练认知负担。展开更多
激光雷达在扫描周围环境时会产生部分杂乱且稀疏的点云,该类点云会在配准过程中产生过大的分布拟合误差和关联距离,进而影响配准算法的精度及同步定位与建图(simultaneous localization and mapping,SLAM)的效果。针对以上问题,提出了...激光雷达在扫描周围环境时会产生部分杂乱且稀疏的点云,该类点云会在配准过程中产生过大的分布拟合误差和关联距离,进而影响配准算法的精度及同步定位与建图(simultaneous localization and mapping,SLAM)的效果。针对以上问题,提出了一种基于分布优化配准的实时激光SLAM算法。设计了一个特征谱滤波器,该滤波器以归一化最小特征值为滤波对象,去除不符合设定分布的点云以减小分布拟合误差;提出了一个点云配准损失函数,对源点云和目标点云构成的联合协方差矩阵和误差项进行复合归一化,以减小关联距离过大的点在迭代求解过程中的干扰;设计了一个SLAM算法框架,该框架包含前端里程计、回环检测和后端优化等环节,兼容纯激光建图和激光/惯性融合建图,进而保证建图的精确性和一致性,并提高了算法的适应性。在公开数据集上进行了多组实验,实验结果表明,相较于现有SLAM算法,所提算法在精度和速度指标方面均具有较大优势。展开更多
基金the National Key Research and Development Program of China(2016YFB1001501)NSF of China(61672457)+1 种基金the Fundamental Research Funds for the Central Universities(2018FZA5011)Zhejiang University-SenseTime Joint Lab of 3D Vision.
文摘Although VSLAM/VISLAM has achieved great success,it is still difficult to quantitatively evaluate the localization results of different kinds of SLAM systems from the aspect of augmented reality due to the lack of an appropriate benchmark.For AR applications in practice,a variety of challenging situations(e.g.,fast motion,strong rotation,serious motion blur,dynamic interference)may be easily encountered since a home user may not carefully move the AR device,and the real environment may be quite complex.In addition,the frequency of camera lost should be minimized and the recovery from the failure status should be fast and accurate for good AR experience.Existing SLAM datasets/benchmarks generally only provide the evaluation of pose accuracy and their camera motions are somehow simple and do not fit well the common cases in the mobile AR applications.With the above motivation,we build a new visual-inertial dataset as well as a series of evaluation criteria for AR.We also review the existing monocular VSLAM/VISLAM approaches with detailed analyses and comparisons.Especially,we select 8 representative monocular VSLAM/VISLAM approaches/systems and quantitatively evaluate them on our benchmark.Our dataset,sample code and corresponding evaluation tools are available at the benchmark website http://www.zjucvg.net/eval-vislam/.
基金Sponsored by the Beijing Education Committee Cooperation Building Foundation Project
文摘A new method for speeding up the state augment operations involved in the compressed extended Kalman filter-based simultaneous localization and mapping （CEKF-SLAM） algorithm was proposed. State augment usually requires a fully-updated state eovariance so as to append the information of newly observed landmarks, thus computational volume increases quadratically with the number of landmarks in the whole map. It was proved that state augment can also be achieved by augmenting just one auxiliary coefficient ma- trix. This method can yield identical estimation results as those using EKF-SLAM algorithm, and computa- tional amount grows only linearly with number of increased landmarks in the local map. The efficiency of this quick state augment for CEKF-SLAM algorithm has been validated by a sophisticated simulation project.
文摘载体定位是实现自动驾驶的关键技术之一,其中基于地图的定位技术具有精度高和鲁棒性强的优点。同步定位与建图(simultaneous localization and mapping,SLAM)技术是针对未知环境地图构建的典型方法,在地铁隧道场景中,传统SLAM算法易因几何结构的严重退化而导致建图失败。针对此问题,文章提出一种基于点云强度特征的建图算法。其首先进行基于点云强度的特征点云提取,并根据广义迭代最近点算法完成高强度特征点云残差构建,以增加运动约束;其次,基于位姿图优化融合激光雷达数据与惯性测量单元数据,完成位姿优化与地图构建;最后,使用地铁隧道离线数据进行算法验证,结果显示,采用该方法成功构建了地铁全线的点云地图,地图无明显漂移,并采用隧道壁上固定安装距离的标识物体进行地图精度评估,所建地图平均偏差小于0.2m,验证了所提算法的有效性与鲁棒性。
基金National Key Research and Development Program of China(2017YFB1002601)National Natural Science Foundation of China(61632003,61771026)The authors thank Xin WANG,Qiuyuan WANG,Fei XUE,Pijian SUN,Shunkai LI,Junqiu WANG,Zhaoyang LV,and Wei DONG for their instructive discussion and feedback.
文摘Simultaneous localization and mapping(SLAM)has attracted considerable research interest from the robotics and computer-vision communities for>30 years.With steady and progressive efforts being made,modern SLAM systems allow robust and online applications in real-world scenes.We examined the evolution of this powerful perception tool in detail and noticed that the insights concerning incremental computation and temporal guidance are persistently retained.Herein,we denote this temporal continuity as a flow basis and present for the first time a survey that specifically focuses on the flow-based nature,ranging from geometric computation to the emerging learning techniques.We start by reviewing two essential stages for geometric computation,presenting the de facto standard pipeline and problem formulation,along with the utilization of temporal cues.The recently emerging techniques are then summarized,covering a wide range of areas,such as learning techniques,sensor fusion,and continuous time trajectory modeling.This survey aims at arousing public attention on how robust SLAM systems benefit from a continuously observing nature,as well as the topics worthy of further investigation for better utilizing the temporal cues.
文摘目的研究增强现实(augmented reality,AR)航天飞行训练空间定位问题。方法采用同步定位与建图(simultaneous localization and mapping,SLAM)技术提出增强现实航天飞行训练系统框架;构建包含图像获取,特征提取描述与匹配、相机位姿估计,图优化以闭环检测及构图的空间定位算法,并对算法进行实验验证。结果通过与高精度全站仪数据比较,验证了算法的测量精度和有效性。结论本文方法能够以主动方式向航天员提供飞行训练引导信息,减轻航天飞行训练认知负担。
文摘激光雷达在扫描周围环境时会产生部分杂乱且稀疏的点云,该类点云会在配准过程中产生过大的分布拟合误差和关联距离,进而影响配准算法的精度及同步定位与建图(simultaneous localization and mapping,SLAM)的效果。针对以上问题,提出了一种基于分布优化配准的实时激光SLAM算法。设计了一个特征谱滤波器,该滤波器以归一化最小特征值为滤波对象,去除不符合设定分布的点云以减小分布拟合误差;提出了一个点云配准损失函数,对源点云和目标点云构成的联合协方差矩阵和误差项进行复合归一化,以减小关联距离过大的点在迭代求解过程中的干扰;设计了一个SLAM算法框架,该框架包含前端里程计、回环检测和后端优化等环节,兼容纯激光建图和激光/惯性融合建图,进而保证建图的精确性和一致性,并提高了算法的适应性。在公开数据集上进行了多组实验,实验结果表明,相较于现有SLAM算法,所提算法在精度和速度指标方面均具有较大优势。
