A Vehicle-Borne Mobile Mapping System Based Framework for Semantic Segmentation and Modeling on Overhead Catenary System Using Deep Learning

Abstract

Overhead catenary system (OCS) automatic detection is of important significance for the safe operation and maintenance of electrified railways. The vehicle-borne mobile mapping system (VMMS) may significantly improve the data acquisition. This paper proposes a VMMS-based framework to realize the automatic detection and modelling of OCS. The proposed framework performed semantic segmentation, model reconstruction and geometric parameters detection based on LiDAR point cloud using VMMS. Firstly, an enhanced VMMS is designed for accurate data generation. Secondly, an automatic searching method based on a two-level stereo frame is designed to filter the irrelevant non-OCS point cloud. Then, a deep learning network based on multi-scale feature fusion and an attention mechanism (MFF_A) is trained for semantic segmentation on a catenary facility. Finally, the 3D modelling is performed based on the OCS segmentation result, and geometric parameters are then extracted. The experimental case study was conducted on a 100 km high-speed railway in Guangxi, China. The experimental results show that the proposed framework has a better accuracy of 96.37%, outperforming other state-of-art methods for segmentation. Compared with traditional manual laser measurement, the proposed framework can achieve a trustable accuracy within 10 mm for OCS geometric parameter detection.

Point Cloud Analysis of Railway Infrastructure: A Systematic Literature Review

“…The reception and accuracy of GNSS is not always consistent, therefore GNSS data is often augmented with gyroscope, heading and odometer data. The work of Xu et al sheds some light on this matter [66]. During the processing of raw frames into larger scenes, also duplicate measurements are excluded.…”

“…• Rotational correction and projection of 3D points, fitting a pre-defined rail model, and interpolation using Fourier curve fitting [62]. • Piecewise straight line fitting for contact wire and dropper [66]. • Identifying and classifying railway cables (contact, catenary, return current) [35].…”