Contact wire position measurement on trolley-based system using 3D Laser-Scanning with geometric constraint method

Abstract

The position of overhead contact wire (POCW) is a critical technical parameter for electrified rail transportation systems, and should be measured using contactless approaches. Although various contactless POCW measuring systems have been developed, their limited accuracy and insufficient coverage remain challenges. This paper presents a novel trolley-based system for efficient and accurate POCW measurement. This system integrates the POCW measurement system with an inertial track geometric measurement system, which can be used to measure the absolute POCW. The proposed system uses 3D laser-scanning with a line profiler (3D-LLP) and a robust POCW estimation method to overcome ambient light, speckles, and reflections. The estimation method employs a least-squares circle fitting technique utilizing prior OCW information and geometric photographic constraints. Laboratory and railway experiments demonstrate the system's robustness, accuracy, and precision. Some prospects were proposed for further improving the measurement performance.