Tramway Track: A New Approach for Measuring the Transverse Profile of Worn-Out Rails

A New High-Efficiency Procedure for Aggregate Gradation Determination of the Railway Ballast by Means Image Recognition Method

“…For instance, in the image of Figure 3 the application of Otsu's method develops the binary image as in Figure 4 and its respective pixel intensity (variance) histogram is illustrated in Figure 5. Furthermore, it has been ascertained that [1,2,3], though individually segmented, each chromatic plane (RGB) of the same image provides, as expected, results that are almost identical. In order to simplify and to speed up the whole procedure, only the red chromatic plane was subject to thresholding.…”

“…As a matter of fact, the thresholded image with Otsu's method is highly infl uenced by the colorimetric intensity of each grain and/or by the local lighting variations of the scene which, on the other hand, in outdoor environment, are highly dependent of the time when the image is taken. In light of the above, the suggested procedure extracts the grain boundaries from the original image by means of the iterative algorithm discussed in [1,2,3]. Once closed and connected regions of grains have been obtained, their boundaries have been processed via a specifi cally adapted Watershedtype algorithm [13,14] in order to check and, if needed, repair the irregularities in the grain boundary shape as well as to subdivide the connected regions with a slight difference in colorimetric texture.…”

“…The next step is to extract the boundary contours {C} between grains from the image in Figure 7 and there marked in black. To this end, an appropriate binary morphological function [1,2,14,16] encodes every grain perimeter which, in this image, also represents the possible separation surface from the background. The result of such an activity is reported in Figure 8.…”

“…A specifi c research has therefore been carried out to develop a procedure for determining railway ballast particle size distribution by means of the image processing technique. Such a technique has already given very good results when adopted in railway monitoring [1,2,3,4,5] as well as in numerous other fi elds of transport engineering [6,7,8,9,10,11]. The equipment used in the analyses consists of a high-resolution 16.1MP camera placed on a tripod at a prefi xed height of 0.80 m. The experimentation has been conducted on a new Italian railway line, along the section "EMS/La Malfa -Cardillo" in Palermo which already had laboratory data acquired by a certifi ed authority and in complete conformity with the Italian Railway Network Specifi cations (Capitolato RFI, n. XXXX OD D IF SP XX.XX.X.X 001 B).…”

A numerical analysis of the contact stress distribution and physical modelling of abrasive wear in the tram wheel-frog system

“…The load, slippage and properties of the materials used have a decisive influence on the wear in the wheel rail system [2][3][4][5]. The load imposed on a rail and caused by the pressure of the rail vehicle wheels, which is a function of tram mass, induces a specific state of contact stresses in the contact place of the material.…”