Rail Track Detection and Projection-Based 3D Modeling from UAV Point Cloud

Abstract

The expansion of the railway industry has increased the demand for the three-dimensional modeling of railway tracks. Due to the increasing development of UAV technology and its application advantages, in this research, the detection and 3D modeling of rail tracks are investigated using dense point clouds obtained from UAV images. Accordingly, a projection-based approach based on the overall direction of the rail track is proposed in order to generate a 3D model of the railway. In order to extract the railway lines, the height jump of points is evaluated in the neighborhood to select the candidate points of rail tracks. Then, using the RANSAC algorithm, line fitting on these candidate points is performed, and the final points related to the rail are identified. In the next step, the pre-specified rail piece model is fitted to the rail points through a projection-based process, and the orientation parameters of the model are determined. These parameters are later improved by fitting the Fourier curve, and finally a continuous 3D model for all of the rail tracks is created. The geometric distance of the final model from rail points is calculated in order to evaluate the modeling accuracy. Moreover, the performance of the proposed method is compared with another approach. A median distance of about 3 cm between the produced model and corresponding point cloud proves the high quality of the proposed 3D modeling algorithm in this study.

A Projection-Based Reconstruction Algorithm for 3d Modeling of Bridge Structures From Drone-Based Point Cloud

“…In this paper, the proposed 3D modeling workflow is a projection-based method (Arefi and Reinartz, 2013;Sahebdivani et al, 2020) which transfers the 3D point cloud to an orthogonal plane and generates 2D models using primitive points. The final model is formed by merging individual models based on horizontal and vertical curvatures of the bridge.…”

“…Similar to our previous study (Sahebdivani et al, 2020), we model the linear railing elements on both sides of the bridge, separately. First, the points of each railing element are identified and extracted using the RANSAC-based line-fitting algorithm.…”

Drone-Based Container Crane Inspection: Concept, Challenges and Preliminary Results

“…The laborious, time-consuming, unsafe and subjective nature of manual inspections motivate research into methods for automating such inspections. Drones have become an efficient tool in many * Corresponding author applications due to the flexible use in data capturing process (Kerle et al, 2019;Nex & Remondino, 2014;Sahebdivani et al, 2020). Therefore, a logical step forward in increasing the automation of container cranes' inspection is employing the photos taken by drones and the visual evaluation of the photos with the help of qualified specialists.…”

Application of Rail Track Geometry Measuring Trolleys for Georeferencing of Uav Images

“…3D models are often stored in up-todate databases for maintaining the railways (Jwa, Sonh, 2015). For detecting rails with high accuracy special algorithms and techniques are being developed (Sahebdivani et al, 2020). One of the latest methods for rail line extraction from UAV images was proposed by Tong et al, 2020. Regardless of survey parameters not all UAV models can provide an acceptable accuracy of processed data for solving a certain task.…”