In-Service Detection and Quantification of Railway Wheel Flat by the Reflective Optical Position Sensor.

Run Gao,Qixin He,Qibo Feng,Jianying Cui

doi:10.3390/s20174969

Abstract

Railway wheel tread flat is one of the main faults of railway wheels, which brings great harm to the safety of vehicle operation. In order to detect wheel flats dynamically and quantitatively when trains are running at high speed, a new wheel flat detection system based on the self-developed reflective optical position sensor is demonstrated in this paper. In this system, two sensors were mounted along each rail to measure the wheel-rail impact force of the entire circumference by detecting the displacement of the collimated laser spot. In order to establish a quantitative relationship between the sensor signal and the wheel flat length, a vehicle-track coupling dynamics analysis model was developed using the finite element method and multi-body dynamics method. The effects of train speed, load, wheel flat lengths, as well as the impact positions on impact forces were simulated and evaluated, and the measured data can be normalized according to the simulation results. The system was assessed through simulation and laboratory investigation, and real field tests were conducted to certify its validity and correctness. The system can determine the position of the flat wheel and can realize the quantification of the detected wheel flat, which has extensive application prospects.

Highlights

With the development of railway transportation towards faster speeds and larger axle loads, the wheel-rail contract force is increasing, which puts forward higher quality requirements on the wheels
The the laser collimation method-based flat detection system was mounted in laboratories simulation results were normalized wheel to realize quantitative measurement
Effectiveness of the system, the laser collimation method-based wheel flat detection system was mounted in laboratories and railway sites, respectively, and experiments in the laboratory and on5.1

Summary

Introduction

With the development of railway transportation towards faster speeds and larger axle loads, the wheel-rail contract force is increasing, which puts forward higher quality requirements on the wheels. Wheel flat is the most common local surface defect in the service life of railway wheels. The reason for this defect is mainly related to abnormal braking of the vehicle, and may be caused by low wheel-rail adhesion due to environmental conditions (rain, snow, leaves, etc.), which makes the wheel slide locally on the rail surface [1,2,3]. Wheel flats will bring additional periodic impact load to the rail during vehicle operation, giving rise to high impact forces in the wheel-rail interface. The deterioration is the inevitable result of increasing wheel-rail contact force. The rapid and accurate detection of overrun flat wheels has become the most important issue for researchers

Methods

Discussion

Conclusion