Analysis of Lidar Actuator System Influence on the Quality of Dense 3D Point Cloud Obtained with SLAM

Abstract

Mobile mapping technologies, based on techniques such as simultaneous localization and mapping (SLAM) and surface-from-motion (SfM), are being vigorously developed both in the scientific community and in industry. They are crucial concepts for automated 3D surveying and autonomous vehicles. For various applications, rotating multiline scanners, manufactured, for example, by Velodyne and Ouster, are utilized as the main sensor of the mapping hardware system. However, their principle of operation has a substantial drawback, as their scanning pattern creates natural gaps between the scanning lines. In some models, the vertical lidar field of view can also be severely limited. To overcome these issues, more sensors could be employed, which would significantly increase the cost of the mapping system. Instead, some investigators have added a tilting or rotating motor to the lidar. Although the effectiveness of such a solution is usually clearly visible, its impact on the quality of the acquired 3D data has not yet been investigated. This paper presents an adjustable mapping system, which allows for switching between a stable, tilting or fully rotating lidar position. A simple experiment in a building corridor was performed, simulating the conditions of a mobile robot passing through a narrow tunnel: a common setting for applications, such as mining surveying or industrial facility inspection. A SLAM algorithm is utilized to create a coherent 3D point cloud of the mapped corridor for three settings of the sensor movement. The extent of improvement in the 3D data quality when using the tilting and rotating lidar, compared to keeping a stable position, is quantified. Different metrics are proposed to account for different aspects of the 3D data quality, such as completeness, density and geometry coherence. The ability of SLAM algorithms to faithfully represent selected objects appearing in the mapped scene is also examined. The results show that the fully rotating solution is optimal in terms of most of the metrics analyzed. However, the improvement observed from a horizontally mounted sensor to a tilting sensor was the most significant.

Design of structured meshes of mining excavations based on variability trends of real point clouds from laser scanning for numerical airflow modeling

“…It is used to map an unknown environment while estimating the exact location of the sensor. It can be mounted on a robot [25] or a UAV [26], as well as a hand-held [4]. The main sensors used in SLAM technology are LiDARs [27] and cameras [28].…”

LiDAR-based SLAM for robotic mapping: state of the art and new frontiers

“…Although the sensor rotating in its entire range produced the greatest results, a tilting sensor produced results that were not significantly poorer than the static, horizontal location of the LiDAR (shown in Figure 5) (Trybała et al , 2023).…”

Comparison of TLS and SLAM technologies for 3D reconstruction of objects with different geometries

“…TLS scanners are usually placed directly on the ground or mounted on ground platforms such as tripods, often equipped with additional components such as cameras or Global Navigation Satellite System (GNSS) receivers [14]. Another often used method is Mobile Laser Scanning (MLS) where the LiDAR sensor is handheld or mounted onboard a moving platform (a car, a boat, or a robot) [15]. In the case of flying platforms, it is called Aerial (or Airborne) Laser Scanning (ALS) [16].…”