As one of the most important transportation, the safety of railway is paid much attention to. The quality of wheel should
be checked periodically, especially in high-speed application. Normally, Non Destructive Testing (NDT), such as
ultrasonic inspection method, is applied on wheels to find the defect. A stationary automatic railway wheelset inspection
system by using ultrasonic technique is described in this paper. The phased array ultrasonic technique and wheel defect
inspection method is described in detail. Specially designed line is installed for wheelset transportation. Wheelset lifting
and rotating device is used for wheelset loading, unloading and rotating. A steel frame with complicated mechanical
structure and ultrasonic devices are designed for wheelset defect detecting. System ultrasonic performance, system
working flow, system control networking, data processing and results displaying are also described in the paper. Now,
the system is installed in Chinese EMU maintenance center for disassembled wheelset inspection and the safety of
wheels is well protected.
A dynamic detection technology for the irregularity state of railway track by means of linear array CCD sensor is
introduced, and the detecting method, the structure of the system are also described in detail. In this paper, a model of
2-meter chord measuring method is established; the digital inverse filter is analyzed and simulated to get the irregularity
state of railway track. The analysis and Summary about how to apply the inverse filter are given. Finally some
experiment result and detection data are given from the depot.
The railway line profile measurement is necessary for the safety of the train. This article expounds a method of railway line profile measuring using laser ranging and laser scanning technology with high precision and speed. With this method, the obstacle near the track can be found out and the hidden trouble can be removed. In tunnel, the crack and deformation on the tunnel wall can be measured. The parameter of the track and contact wire can be also inspected, such as rail gauge and superelevation, position of contact wire (stagger and height), wire wearing.
In this paper, the importance of the contact line height and gradient in the electrified railway and the current inspection methods for the contact line height and gradient are analyzed, and then the dynamic detection system for that is deigned, which based on the laser phase ranging principle. The detection system is setting on the top of locomotive and a cooperative target is fixed on the pantograph; the laser system measures the height between the top of locomotive and the working pantograph by the cooperative target when the locomotive runs, and then the gradient of contact line can be calculated in real time when the locomotive's running information is provided. The laser phase ranging system uses the DFT method to calculate the phase difference, which can get the higher resolution than the method of the electronic phase demodulation and reduce the influence of the shift of laser intensity etc. The dynamic detection system works well to detect the contact line gradient, without influencing the normal operation of the locomotive, and the disadvantages of manual detecting and detecting car are avoided.
Flange Height and Flange Thickness are vital parameters for train wheels. Usually, they are manually measured by wheel
vernier after train stopped. This article introduces a dynamic wheel inspection system. Pulsed slit diode lasers project
onto wheel tread while train is in motion, CCD cameras record light-section images of wheel profile. Geometric
parameters and profile of wheel are measured on basis of image processing. This paper introduces measuring principle
and structure of this inspection system, analyzes influences resulted from laser parameters and environment, designs
instantaneous high-powered slit diode laser and narrowband optical filter according to ±0.2mm accuracy requirement
and environment situation.