28 accepted papers
In this paper, we propose a non-parametric method for estimating the posterior distribution of global positioning satellite systems (GNSS) integer ambiguity. It is difficult to estimate the posterior probability of discrete integer ambiguities directly from carrier phase observations due to the uncl
This paper presents range-based 6-DoF Monte Carlo SLAM with a gradient-guided particle update strategy. While non-parametric state estimation methods, such as particle filters, are robust in situations with high ambiguity, they are known to be unsuitable for high-dimensional problems due to the curs
Accurate localization is essential for enabling modern full self-driving services. These services heavily rely on map-based traffic information to reduce uncertainties in recognizing lane shapes, traffic light locations, and traffic signs. Achieving this level of reliance on map information requires
In this letter, we present tightly coupled LiDAR-IMU-leg odometry, which is robust to challenging conditions such as featureless environments and deformable terrains. We developed an online learning-based leg kinematics model named the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xli
This paper presents an accurate and fast 3D global localization method, 3D-BBS, that extends the existing branchand-bound (BnB)-based 2D scan matching (BBS) algorithm. To reduce memory consumption, we utilize a sparse hash table for storing hierarchical 3D voxel maps. To improve the processing cost…
This paper presents a 6-DoF range-based Monte Carlo localization method with a GPU-accelerated Stein particle filter. To update a massive amount of particles, we propose a Gauss-Newton-based Stein variational gradient descent (SVGD) with iterative neighbor particle search. This method uses SVGD to c…
This paper presents a range inertial localization algorithm for a 3D prior map. The proposed algorithm tightly couples scan-to-scan and scan-to-map point cloud registration factors along with IMU factors on a sliding window factor graph. The tight coupling of the scan-to-scan and scan-to-map registr…
This paper presents a point cloud downsampling algorithm for fast and accurate trajectory optimization based on global registration error minimization. The proposed algorithm selects a weighted subset of residuals of the input point cloud such that the subset yields exactly the same quadratic point…
This paper presents an open source LiDAR-camera calibration toolbox that is general to LiDAR and cam-era projection models, requires only one pairing of LiDAR and camera data without a calibration target, and is fully automatic. For automatic initial guess estimation, we employ the Super-Glue image…
This study presents a framework, L-C*, for resilient and lightweight direct visual localization, employing a loosely coupled fusion of visual and inertial data. Unlike indirect methods, direct visual localization facilitates accurate pose estimation on general color three-dimensional maps that are n…
This letter presents a LiDAR odometry estimation framework called Generalized LOAM. Our proposed method is generalized in that it can seamlessly fuse various local geometric shapes around points to improve the position estimation accuracy compared to the conventional LiDAR odometry and mapping (LOAM
This paper presents a real-time 3D mapping framework based on global matching cost minimization and LiDAR-IMU tight coupling. The proposed framework comprises a preprocessing module and three estimation modules: odometry estimation, local mapping, and global mapping, which are all based on the tight…
This paper presents an accurate and scalable method for fiducial tag localization on a 3D prior environmental map. The proposed method comprises three steps: 1) visual odometry-based landmark SLAM for estimating the relative poses between fiducial tags, 2) geometrical matching-based global tag-map r…
This study presents a framework for capturing human attention in the spatio-temporal domain using eye-tracking glasses. Attention mapping is a key technology for human perceptual activity analysis or Human-Robot Interaction (HRI) to support human visual cognition; however, measuring human attention
This study proposes an adaptive data-driven hy-perparameter tuning framework for black-box 3D LiDAR odometry algorithms. The proposed framework comprises offline parameter-error function modeling and online adaptive parameter selection. In the offline step, we run the odometry estimation algorithm f…
LiDAR odometry algorithms are complex and involve a number of hyper-parameters. The choice of hyper-parameters can substantively affect the performance of odometry estimation, and it is necessary to carefully fine-tune the hyper-parameters depending on the sensor, environment, and algorithm to achie…
This letter presents a real-time 3D LiDAR mapping framework based on global matching cost minimization. The proposed method constructs a factor graph that directly minimizes matching costs between frames over the entire map, unlike pose graph-based approaches that minimize errors in the pose space.
This letter presents an interactive graph SLAM framework with a 3D LIDAR. This framework allows the user to interactively correct a 3D environmental map generated by an automatic SLAM system. By optimizing a pose graph consisting of pose constraints created by the automatic SLAM and map correction c
In this paper, a three-dimensional light detection and ranging simultaneous localization and mapping (SLAM) method is proposed that is available for tracking and mapping with 500–1000 Hz processing. The proposed method significantly reduces the number of points used for point cloud registration usin…
This paper presents the voxelized generalized iterative closest point (VGICP) algorithm for fast and accurate three-dimensional point cloud registration. The proposed approach extends the generalized iterative closest point (GICP) approach with voxelization to avoid costly nearest neighbor search wh…
We present a monocular camera localization technique for a three-dimensional prior map. Visual localization has been attracting considerable attention as a lightweight and widely available localization technique for any mobilities; however, it still suffers from appearance changes and a high computa
With the aim of contributing to the development of a robotic attendant system, this study proposes the concept of assessing the risk of collision using awareness estimation. The proposed approach enables an attendant robot to assess a person's risk of colliding with an obstacle by estimating whether…
This paper proposes a 3D LiDAR simultaneous localization and mapping (SLAM) method that improves accuracy, robustness, and computational efficiency for an iterative closest point (ICP) algorithm employing a locally approximated geometry with clusters of normal distributions. In comparison with previ…
This paper describes a calibration method for RGB-D camera networks consisting of not only static overlapping, but also dynamic and non-overlapping cameras. The proposed method consists of two steps: online visual odometry-based calibration and depth image-based calibration refinement. It first esti…
This letter describes a novel hand-eye calibration technique based on reprojection error minimization. In contrast to traditional hand-eye calibration methods, the proposed method directly takes images of the calibration pattern and does not require to explicitly estimate the camera pose for each in
This paper describes a person identification method using a smartphone and laser range finders (LRFs) for a mobile service robot. The robot is equipped with LRFs and the target person holds a smartphone. The method first detects the foot strike timings of the target person using the smartphone and t…