Method of optical determination of tack irregularities and defects

FIELD: transport.

SUBSTANCE: Invention relates to railway transport, particularly, to determination of track irregularities and other defects. Propose method consists in defining the level controlled track section of electromagnetic radiation by video control appliances in shifting electromagnetic radiation receiver along said section. Measured level of electromagnetic radiation is used to define track wear and defects. Track image is locked in visible spectrum of electromagnetic radiation in polarisation filter with rotary gating axis and processing of images by estimation of Stocks parameters.

EFFECT: determination of track whatever defects and irregularities by whatever processing means.

4 dwg

 

1. The technical field

The invention relates to the field of rail transport, and in particular to methods of identifying irregularities and other defects in the rail.

2. The level of technology

There is a method of condition monitoring of railway track (patent RU 2123445, UK 9/08, EV 35/00 from 12.07.1995), namely, that detect the angular fluctuations and the coordinates of the axle box of a pair of wheels. Find the coordinates of the touch points of the left and right wheel pair and the drawdown of each rails expressed as the difference between the vertical coordinate of the touch point of the wheel, corresponding to the two points in time. There is also known a method of inertial measurement rail (patent RU 2242391, UK 9/08, EV 35/06 from 30.12.2002), in this way form the vector of the virtual speed of each of the rail lines in the project coordinate system, using the signals from the sensor path, go to the independent variable along the longitudinal coordinate of the path. Integration found velocities receive the vertical and horizontal profiles of rail lines and desired roughness receive as the difference between the measured profiles and their approximarely curves, obtained by processing measurements or passport profiles. The drawbacks are the low sensitivity to small discontinuities smaller than the width of the top support surface of the rail, as well as the need to have a passport profiles of rail lines.

The closest analogue (prototype) is a method of assessing the condition of the track structure (patent RU 2096221, UK 9/06, UK 9/08 from 03.10.1994). How is that determined the level of electromagnetic radiation from the surface of the controlled area, which is compared with a reference corresponding to a given characteristic of the track structure, and by comparing the results reveal the degree of wear and defects of the track structure. The disadvantages of this method are the low sensitivity to small discontinuities smaller than the width of the upper support surface of the rail, and the need to have a passport (reference) profiles of rail lines and the need to install device for nondestructive inspection on special potenzmitteln cars.

3. List of figures, drawings and other materials

Figure 1 presents the block diagram of the image acquisition track: 1 - non-polarized electromagnetic radiation of the visible spectrum; 2 - partially polarized radiation; 3 - track; 4 - polarizing filter rotating axis of the transmission; 5 - receiver electromagnetic radiation of the visible spectrum, 6 is the angle of sight; 7 - normal to the surface of the rail head.

Figure 2 presents the photo of the depression is and the rail, captured in the profile (long depression - 300 mm, depth 3 mm).

Figure 3 shows the original image of the section of rail track in the visible range of the electromagnetic spectrum of radiation.

Figure 4 shows the result of image processing of the depression on the rail, obtained at different positions of the polarization filter, and their subsequent processing by the evaluation of the Stokes parameters.

4. The invention

4.1. Task

The technical challenge is to remedy these disadvantages by fixing the image track in the visible range of the spectrum of electromagnetic radiation using a polarizing filter with a rotating axis of the transmission.

4.2. Distinctive features

The technical result is achieved by the fact that in contrast to the known method, namely, that determine the level of electromagnetic radiation of the surface of the controlled section of railway track by videoendoscope read by moving a receiver of electromagnetic radiation along a specified section, and the measured level of electromagnetic radiation to detect the degree of wear and defects of the track structure is fixed images of rail track in the visible range of the spectrum of electromagnetic radiation through a polarizing filter rotating axis transmittance and PEFC is blowing processing of obtained images by estimating the Stokes parameters.

4.3. The method

The method for the optical determination of the roughness of the track shown in figure 1: non-polarized electromagnetic radiation of the visible spectrum 1 becomes partially polarized 2, reflected from the track 3, passes through a polarizing filter with a rotation shaft of the transmission 4 and enters the receiver of electromagnetic radiation of the visible spectrum 5, further resulting image is processed by the transformation of the Stokes equations, which allows to obtain a clearer image of the defects of the track (including small). This effect is based on the fact that the degree of polarization of the reflected angle of sight 6 (7 is normal to the surface of the rail head), which is a constant for smooth sections of the rail head and changed its irregularities.

5. Information confirming the possibility of carrying out the invention

It is known that when light is reflected from the metal surface there is a change of parameters of polarization, i.e. the polarization characteristics of the reflected light does not coincide with similar characteristics falling (M. born, E. wolf, principles of optics, M., 1973, 716 S.; Sokolov, A.V., Optical properties of metals, M, 1961, 464 S.) Parameters of polarization depends on the angle of sight, which, in turn, is determined by profileproperty rail at the place of observation.

For the implementation of the proposed method was carried out shooting rail track camera Canon 40D with mounted lens Canon EF-S 17-55 f/2.8 IS USM lens and polarizing filter. Used focal length 55 mm For each piece of cloth was done in a series of frames (60 or 30) with different orientation of the polarization filter (step 6 or 12 degrees, respectively), while performed a complete rotation of the filter 360 degrees.

As a model of the echo signal (ICj)registered by the matrix camera at an angle φjbetween the main axis of the polarization filter and a vertical plane passing through the axis of the optical system, we used the following expression:

IC(φj)=12[I+Qcos(2φj)+Usin(2φj)].(1)

For each series of images was calculated estimates of the Stokes parameters

I=2N j=1NIC(φj),(2)

Q=4Nj=1NIC(φj)cos(2φj),(3)

U=4Nj=1NIC(φj)sin(2φj)(4)

and error models:

err2=1N-1j=1N(I +Qcos(2φj)+Usin(2φj)-IC(φj))2,(5)

where N is the number of frames;andφj=2πjN- the rotation angle of the polarizing filter for frame j.

For experiments we used part of the way near the station Rzhevskaya Oktyabrskaya railway, Moscow.

As a first test sample was selected portion of the path with welded rail joint (figure 2). Because of the violation of the structure of the metal in the weld area during long-term operation of such a rail occurs cavity, the length of which was about 30 cm, and the maximum depth was about 3 mm, the Image of the depression on the rail, captured in the profile shown in figure 2.

Figure 3 shows the image of the depression on the rail in natural light, and figure 4 - after processing the original image by estimating the parameters of the Stokes equations. The converted image is their significantly increase the contrast of the depression on the source image.

The method is based on the change of parameters of polarization of the electromagnetic radiation of the visible range reflected from the defects of rail lines, compared to defect-free sections of the route allows you to use as a media equipment in addition to potenzmitteln cars and low-flying aircraft, including remotely-manned aerial vehicles (UAVs). The use of UAVs will improve the performance and efficiency of diagnostics of railway tracks.

The analysis performed by the applicant is known to him prior art showed that the proposed invention has novelty and industrial applicability, is responsible in respect of the totality of its essential features to the requirement of the criterion of "inventive step", in the prior art is unknown mechanism to achieve a technical result disclosed in the application materials.

Method for the optical determination of defects in the track, namely, that determine the level of electromagnetic radiation of the surface of the controlled section of railway track by video reading by moving the receiver of electromagnetic radiation along a specified section, and the measured level of electromagnetic radiation to detect the degree of wear and defects of the track structure is URS, characterized in that the produced image is fixed rail track in the visible range of the spectrum of electromagnetic radiation through a polarizing filter with a rotating axis of the transmission and subsequent processing of the obtained images by estimating the parameters of the Stokes equations.



 

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