Online simultaneous localization and mapping in dynamic environments

The state-of-art simultaneous localization and mapping (SLAM) methods have been demonstrated of satisfactory results in static environments. However, most of the existing methods cannot be directly applied in dynamic environments to account for moving objects. To solve the practical problem of SLAM in dynamic environments, an RGB-D SLAM method is developed based on moving objects removal and dense map reconstruction. Specifically, deep learning-based instance segmentation is performed to obtain the semantic information which is furthermore combined with multiview geometry theory to detect possible moving objects. Kalman filter and feature fusion algorithms are further used for moving objects tracking to improve the detection accuracy. Then the camera pose is estimated using the static feature points after motion removal to realize reliable localization in dynamic environments. Out of concern for the infeasibility of navigation and perception with sparse feature maps, each-single-view of dense map is constructed using the RGB image and the depth map collected by the RGB-D camera after motion removal. The dense environmental map is finally reconstructed through the registration of point cloud of selected key image frames. Experiments are conducted on public datasets and real scene data to evaluate the performance of the proposed method. Compared with the state-of-art method ORB-SLAM2, the absolute trajectory error and the relative pose error obtained by the proposed method are significantly reduced by at least 91%, and the localization accuracy reaches 0.001 m.

Autonomous vehicles operating in real-world industrial environments have to overcome numerous challenges, chief among which is the creation and maintenance of consistent 3D world models. This paper focuses on a particularly important challenge: mapping in dynamic environments. We introduce several improvements to the recently proposed Normal Distributions Transform Occupancy Map (NDT-OM) aimed for efficient mapping in dynamic environments. A careful consistency analysis is given based on convergence and similarity metrics specifically designed for evaluation of NDT maps in dynamic environments. We show that in the context of mapping with known poses the proposed method results in improved consistency and in superior runtime performance, when compared against 3D occupancy grids at the same size and resolution. Additionally, we demonstrate that NDT-OM features real-time performance in a highly dynamic 3D mapping and tracking scenario with centimeter accuracy over a 1.5km trajectory.

SUMMARY Mobile robots need Simultaneous Localization and Mapping (SLAM) for autonomous movement in human living environments. The occupancy grid map used in SLAM is a conventional method which makes a map by an occupancy probability in each grid. This method renews a map based on whether an object is observed or not. In order to remove moving objects from a map, an additional method is required. However, conventional methods deal only with actually moving objects, and potential moving objects (e.g., standing humans) are mapped as static objects. Furthermore, only binary states, used or not used, are given to each object in map updating. This paper proposes the immobility area grid map to represent a map by an immobility probability in each grid. The proposed method renews a map based on the identification of observed objects by a robot's sensors, in addition to whether an object is observed or not. We introduce the map update parameter, which is set adaptively from the certainty of identification result of the object. Observed objects can take continuous states, truly static—unknown—truly moving, according to the parameter value. Potential moving objects are not mapped if the parameter takes values corresponding to moving objects. The experimental results show robust mapping in dynamic environments including potential moving objects.

In this paper we describe a scalable algorithm for the simultaneous mapping and localization (SLAM) problem. SLAM is the problem of acquiring a map of a static environment with a mobile robot. The vast majority of SLAM algorithms are based on the extended Kalman filter (EKF). In this paper we advocate an algorithm that relies on the dual of the EKF, the extended information filter (EIF). We show that when represented in the information form, map posteriors are dominated by a small number of links that tie together nearby features in the map. This insight is developed into a sparse variant of the EIF, called the sparse extended information filter (SEIF). SEIFs represent maps by graphical networks of features that are locally interconnected, where links represent relative information between pairs of nearby features, as well as information about the robot’s pose relative to the map. We show that all essential update equations in SEIFs can be executed in constant time, irrespective of the size of the map. We also provide empirical results obtained for a benchmark data set collected in an outdoor environment, and using a multi-robot mapping simulation.

The importance of indoor mapping has surged across various applications, encompassing human navigation, indoor exploration, and hazardous site mapping. With satellite positioning systems ineffective indoors, alternative navigational sensors and methods, such as inertial measurement units (IMU) and simultaneous localization and mapping algorithms (SLAM), have been harnessed to furnish precise indoor positioning for mapping endeavors. Leveraging LiDAR-based SLAM, which is sensitive to environmental textures and various pose configurations, addresses these challenges. In order to accomplish reliable and precise indoor 3D mapping, this study combines the Velodyne VLP-16 3D-LiDAR sensor with the Pixhawk Cube Orange, which has a 9 Degrees of Freedom (DOF) IMU sensor. The study uses the LIO-SAM (LiDAR Inertial Odometry and Simultaneous Localization and Mapping) technique, which integrates data from LiDAR and IMU to increase mapping precision. It is carried out at the BAAK Dr. Angka Building, Institut Teknologi Sepuluh Nopember, Surabaya. The experimental results reveal that the 3D indoor mapping exhibits commendable visualization and high geometric accuracy, meeting the LoD 3 criteria. Validation using a roll meter yielded a root mean square error (RMSE) of 0.3552 meters, indicating considerable accuracy. The accuracy was further validated by showing LiDAR point cloud errors ranging from 7.92% to 15.75%. Linear regression analysis confirmed a high correlation (R2 0.9954) between LiDAR point cloud measurements and manual measurements, substantiating the method’s reliability. In order to accomplish reliable and precise indoor 3D mapping, this study combines the Velodyne VLP-16 3D-LiDAR sensor with the Pixhawk Cube Orange, which has a 9 Degrees of Freedom (DOF) IMU sensor. The study uses the LIO-SAM (LiDAR Inertial Odometry and Simultaneous Localization and Mapping) technique, which integrates data from LiDAR and IMU to increase mapping precision. It is carried out at the BAAK Dr. Angka Building, Institut Teknologi Sepuluh Nopember, Surabaya.

Frequency-modulated continuous waveform (FMCW) microwave and millimetre-wave radar is an attractive sensor for intelligent transport systems due to its reliable all-weather performance. This paper discusses issues involved in the design of FMCW radar mapping systems for use in collision avoidance in large vehicles operating in dynamic environments. The performance characteristics of radar are examined before an analysis is made of traditional grid-based and feature-based mapping approaches, both conceptually and in terms of implementation. The probability hypothesis density (PHD) filter is discussed as a potentially superior approach for radar mapping in dynamic environments.

In dynamic environments, performance of visual SLAM techniques can be impaired by visual features taken from moving objects. One solution is to identify those objects so that their visual features can be removed for localization and mapping. This paper presents a simple and fast pipeline that uses deep neural networks, extended Kalman filters and visual SLAM to improve both localization and mapping in dynamic environments (around 14 fps on a GTX 1080). Results on the dynamic sequences from the TUM dataset using RTAB-Map as visual SLAM suggest that the approach achieves similar localization performance compared to other state-of-the-art methods, while also providing the position of the tracked dynamic objects, a 3D map free of those dynamic objects, better loop closure detection with the whole pipeline able to run on a robot moving at moderate speed.

Augmented reality (AR) can support neurosurgical procedures by integrating 3-dimensional (3D) images into real-world views to help anatomical understanding. However, current systems are cumbersome and not attractive for trainees. Studies on wearable AR devices show promise but need further refinement. This preliminary report assesses a novel augmented reality navigation system (ARnavS) using a simultaneous localization and mapping algorithm provided with the Vuforia SDK and a quick response code. The system was applied to burr-hole surgeries in 10 cases of chronic subdural hematoma to evaluate its convenience and accuracy. Ten patients with 11 hematomas underwent burr-hole surgeries using ARnavS. The system was effective without equipment issues, with an average registration time of 2.6 minutes. Discrepancy between planned and actual burr-hole locations was 3.5 mm. Skin incisions avoided 3D image of the superficial temporal artery, with no superficial temporal artery damage in any case. The mean surgical time was 37.1 minutes, and no severe postoperative bleeding occurred. Our ARnavS for burr-hole surgery in chronic subdural hematoma offers good 3D imaging with quick registration. It provided surgeons with better anatomical comprehension, helping to avoid injury to critical structures. Unlike conventional systems, ARnavS allows direct visualization of 3D graphics in the surgical field, beneficial for less-experienced neurosurgeons and medical students. While further studies are needed, the AR navigation system with simultaneous localization and mapping algorithm and quick response code showed precise intraoperative 3D imaging with sufficient accuracy after quick registration. While further studies are needed, it has demonstrated practical usefulness in clinical neurosurgical procedures.

Simultaneous localization and mapping (SLAM) plays a crucial role in the field of intelligent mobile robots. However, the traditional Visual SLAM (VSLAM) framework is based on strong assumptions about static environments, which are not applicable to dynamic real-world environments. The correctness of re-localization and recall of loop closure detection are both lower when the mobile robot loses frames in a dynamic environment. Thus, in this paper, the re-localization and loop closure detection method with a semantic topology graph based on ORB-SLAM2 is proposed. First, we use YOLOv5 for object detection and label the recognized dynamic and static objects. Secondly, the topology graph is constructed using the position information of static objects in space. Then, we propose a weight expression for the topology graph to calculate the similarity of topology in different keyframes. Finally, the re-localization and loop closure detection are determined based on the value of topology similarity. Experiments on public datasets show that the semantic topology graph is effective in improving the correct rate of re-localization and the accuracy of loop closure detection in a dynamic environment.

Visual simultaneous localization and mapping (SLAM) is a critical technology for autonomous navigation in dynamic environments. However, traditional SLAM algorithms often struggle to maintain accuracy in highly dynamic environments, where elements undergo significant, rapid, and unpredictable changes, leading to asymmetric information acquisition. Aiming to improve the accuracy of the SLAM algorithm in a dynamic environment, a dynamic SLAM algorithm based on deep learning is proposed. Firstly, YOLOv10n is used to improve the front end of the system, and semantic information is added to each frame of the image. Then, ORB-SLAM2 is used to extract feature points in each region of each frame and retrieve semantic information from YOLOv10n. Finally, through the map construction thread, the dynamic object feature points extracted by YOLOv10n are eliminated, and the construction of a static map is realized. The experimental results show that the accuracy of the proposed algorithm is improved by more than 96% compared with the state-of-the-art ORB-SLAM2 in a highly dynamic environment. Compared with other dynamic SLAM algorithms, the proposed algorithm has improved both accuracy and runtime.

The integration of Autonomous Mobile Robots (AMRs) with LiDAR technology and 5G connectivity presents transformative potential for hospital environments. This study evaluates the performance of these technologies in critical metrics such as latency, throughput, reliability, and reaction time, with an emphasis on their application in the automation of logistics tasks, such as the transportation of medical materials. The results indicate that 5G networks outperform WiFi in terms of low latency, high throughput, and performance consistency, making them ideal for real-time applications. In addition, LiDAR technology enhances the navigation of AMRs by providing accurate three-dimensional mapping in dynamic environments. Despite promising technical advances, challenges remain, including infrastructure costs, interoperability, and cybersecurity concerns. The findings highlight the need for multidisciplinary approaches to overcome these barriers and pave the way for innovative solutions in healthcare. This research contributes to the growing knowledge about the applications of Industry 4.0 in the healthcare sector, aiming to improve the efficiency, safety, and quality of patient care.

Significant advances have been achieved in mobile robot localization and mapping in dynamic environments, however these are mostly incapable of dealing with the physical properties of automotive radar sensors. In this paper we present an accurate and robust solution to this problem, by introducing a memory efficient cluster map representation. Our approach is validated by experiments that took place on a public parking space with pedestrians, moving cars, as well as different parking configurations to provide a challenging dynamic environment. The results prove its ability to reproducibly localize our vehicle within an error margin of below 1% with respect to ground truth using only point based radar targets. A decay process enables our map representation to support local updates.

Simultaneous localization and mapping (SLAM) has been richly researched in past years particularly with regard to range-based or visual-based sensors. Instead of deploying dedicated devices that use visual features, it is more pragmatic to exploit the radio features to achieve this task, due to their ubiquitous nature and the wide deployment of Wifi wireless network. In this paper, we present a novel approach for crowd-sensing simultaneous localization and radio fingerprint mapping (C-SLAM-RF) in large unknown indoor environments. The proposed system makes use of the received signal strength (RSS) from surrounding Wifi access points (AP) and the motion tracking data from a smart phone (Tango as an example). These measurements are captured duration the walking of multiple users in unknown environments without map information and location of the AP. The experiments were done in a university building with dynamic environment and the results show that the proposed system is capable of estimating the tracks of a group of users with an accuracy of 1.74 meters when compared to the ground truth acquired from a point cloud-based SLAM.

Simultaneous localization and mapping (SLAM) is a central and complex problem in robot research community. In SLAM, extended Kalman filter (EKF) implementation is widely used to localize the robot and build the environment map incrementally. In this paper, we propose a strong tracking filter (STF) SLAM algorithm. This algorithm applies STF to deal with the non-linear estimated problem in SLAM instead of EKF. It can make the performance of the nonlinear filter approximate to that of optimal linear Kalman Filter (KF), so it can construct high accuracy maps and locate the robot more accurately than EKF SLAM. Simulation experiments illustrate the superior performance of our approach compared to EKF SLAM algorithm.

In order to solve the shortcomings of traditional simultaneous localization and mapping in dynamic environment, which is interfered by moving objects, resulting in low accuracy and poor robustness, a visual simultaneous localization and mapping algorithm combining semantic information for motion detection was proposed. First, the SegNet deep neural network is used to extract the semantic information of the environment, and the prior knowledge is used to determine the static attribute objects and dynamic attribute objects. In the motion detection module, the feature points on the dynamic attribute objects are used to perform motion detection using geometric constraint relationships. Then the building module uses semantic information to build a semantic octo-tree map. In order to analyse the effect of motion detection, a control experiment with a motion detection module removed was set up. Finally, experiments were conducted using TUM datasets, and the experimental results of the two schemes were compared and analysed.