Track gauge dynamic measurement based on 2d laser displacement sensor
Track irregularities can cause deterioation of riding comfort and derailment. Track gauge variation is one of the basic track irregularities. Track Recording Car is an automated track inspection vehicle on a rail transport system used to test several geometric parameters of the track. Track geomeotry parameters generally measured include position, speed, gauge, alignment, crosslevel, curvature and so on. This paper presents a novel technique for the measurement of track gauge variation, a new measurement system was introduced and been in assembled on a new type underground track recording car.
Integrating the Symmetry Image and Improved Sparse Representation for Railway Fastener Classification and Defect Recognition
The detection of fastener defects is an important task for ensuring the safety of railway traffic. The earlier automatic inspection systems based on computer vision can detect effectively the completely missing fasteners, but they have weaker ability to recognize the partially worn ones. In this paper, we propose a method for detecting both partly worn and completely missing fasteners, the proposed algorithm exploits the first and second symmetry sample of original testing fastener image and integrates them for improved representation-based fastener recognition. This scheme is simple and computationally efficient. The underlying rationales of the scheme are as follows: First, the new virtual symmetrical images really reflect some possible appearance of the fastener; then the integration of two judgments of the symmetrical sample for fastener recognition can somewhat overcome the misclassification problem. Second, the improved sparse representation method discarding the training samples that are “far” from the test sample and uses a small number of samples that are “near” to the test sample to represent the test sample, so as to perform classification and it is able to reduce the side-effect of the error identification problem of the original fastener image. The experimental results show that the proposed method outperforms state-of-the-art fastener recognition methods.
The Use Of Solid-State Image Scanners In The British Railways Track Recording Coach
The measurement of lateral track parameters, using contacting sensors, from a high-speed rail vehicle presents problems due to the vulnerability of mechanical probes and feelers. To overcome these problems a non-contacting system based on commercially available solid-state scanners has been developed by British Railways. The sensor equipment consists of two separate linescan cameras mounted vertically above each rail. The rails are obliquely illuminated from projectors mounted on the bogie (truck), and it is possible by processing the camera video signals to detect -that part of the scan corresponding to the gauge face of each rai1. This information can then be used to calculate track gauge, and, in conjunction with other equipment, track alignment.