Real-Time Geometric Parameter Measurement of High-Speed Railway Fastener Based on Point Cloud from Structured Light Sensors.

Hao Cui,Qingwu Hu,Qingzhou Mao

doi:10.3390/s18113675

Abstract

With the increase in the number of service years for high-speed railways, the foundation of the rail track suffers from settlement, which causes rail track irregularity. To adjust the position of the track and meet track regularity demands, several components of the fastening system will be replaced by different sized components. It is important to measure the exact geometric parameters for the components of a fastening system before adjusting the track. Currently, the measurement process is conducted manually, which is laborious and error-prone. In this paper, a real-time geometric parameter measurement system for high-speed railway fastener based on 2-D laser profilers is presented. Dense and precise 3-D point clouds of high-speed railway fasteners are obtained from the system. A fastener extraction method is presented to extract fastener point cloud and a region-growing algorithm is used to locate key components of the fastener. Then, the geometric parameter of the fastener is worked out. An experiment was conducted on a high-speed railway near Wuhan, China to verify the accuracy and repeatability of the system. The maximum root-mean-square-error between the manual measurement and the system measurement is 0.3 mm, which demonstrates adequate accuracy. This system can replace manual measurements and greatly improve the efficiency of geometric parameter measurements for fasteners.

Highlights

Fasteners are critical parts of high-speed railway system, as they can fasten the rail track onto the track slab and maintain the track gauge
Thesensors sensorscan can provide provide a a maximum are are used in the measurement system
Field tests were conducted on a high-speed railway, and the geometric parameter of the fasteners was measured manually to verify the results of the IRC

Summary

Introduction

Fasteners are critical parts of high-speed railway system, as they can fasten the rail track onto the track slab and maintain the track gauge. A typical high-speed railway fastening system (Figure 1). Consists of a metal clip, bolts, an insulation block, a support pad and a height adjustment pad. The rail track of high-speed railway need to be adjusted accurately to ensure the high demands of track regularity [1,2]. During the adjustment of the track, the insulation block and the height adjustment pad may be replaced by those of different sizes according to the track adjustment plan [3,4,5]. WJ-7, WJ-8, and Vossloh-300 are most commonly used type of fastener in China’s high-speed railways It is crucial to identify exact geometric parameters of the fastening system before adjusting the track.

Methods

Results

Conclusion