RU2818020C1 - Rolling stock wheel pair defect control system - Google Patents

Abstract

FIELD: railway automation and telemechanics.

SUBSTANCE: rolling stock wheel pair defect control system comprises a single-mode fibre-optic cable laid in the ground, one side of which is made with a sealed plug, other side is connected to input/output of coherent reflectometer, by other output connected to input of processing unit, and a sensitive element connected to the fibre of the fibre-optic cable, which includes k turns of single-mode optical fibre, fixed on the sensitive membrane of the rear wall of the horn, horn is installed on a support at a given distance from the rail and height from the level of the railroad bed with the direction of the central axis of the horn to the point of contact of the wheel rolling surface with the rail surface, also used is a horn with geometrical dimensions, providing maximum coefficient of sound wave energy concentration on sensitive membrane, number of turns is selected depending on pulse width of coherent optical radiation of reflectometer laser.

EFFECT: improving reliability and accuracy of diagnostics and identification of faults of passing rolling stock wheels in real time.

3 cl, 3 dwg

Description

The invention relates to the field of railway automation and telemechanics and can be used to diagnose the technical condition of wheel sets of passing trains.

A known system for monitoring the rolling surface of a railway wheelset contains dynamic load sensors mounted on the rail, control zone sensors and a processing unit, outputs connected to the first information input of the decision-making unit, the dynamic load sensors are made in the form of fiber-optic pressure sensors placed on measuring section of the track with a length not less than the circumference of the wheel between the sleeper and the rail on opposite sides of the track, the control zone sensors are located along the rail at the beginning and end of the measuring section and are connected through an interface unit to the input of the power supply, as well as to the inputs of the wheel set counter and block for calculating the train speed, the system includes crushed stone ballast temperature sensors installed on both sides of the track at the depth of the sleeper sole, a block of reference temperature values, a comparison block, the inputs of which are connected to the outputs of the temperature sensors and the block of reference temperature values, and the output - to the input of the correction unit, the outputs of which are connected to the inputs of the processing unit, and the other inputs are connected to the outputs of the converter, the inputs of which are connected to the output ends of fiber-optic sensors, the input ends of which are connected to the source of optical radiation, the dynamic coefficient calculation unit, the output of which is connected to the second information input decision-making block, a block for isolating the dynamic component of forces and a block for isolating the static component of forces, connected between the output of the processing block and the inputs of the block for calculating the dynamic coefficient, a car identification block, an indication block and an information storage block, while the outputs of the wheel pair counter and the car identification block are connected to the third and fourth information inputs of the decision-making block, the corresponding inputs/outputs of which are connected to the outputs/inputs of the information storage block, and the other outputs are connected, respectively, to the display block, the adjustment block and through a communication channel with the personal computer of the automated workstation of the dispatch center employee (RU 92840, V61K 9/12, 2010.04.10).

The disadvantage of the known solution is the impossibility of identifying defects in axlebox units when monitoring the rolling surface of a car wheel.

The closest analogue is a system for early diagnostics of axle box bearings of a moving train wheel pair, containing at least twelve acoustic signal receivers, the output of each of which is connected to the corresponding input of the amplification unit, a processing unit including a series-connected bandpass filter, a signal conditioner, an analog - a digital converter and an amplitude detector, an analysis unit containing a block for calculating diagnostic parameters, the inputs of which are connected to the outputs of the amplitude detector, a decision-making block and a comparison block connected between the block for calculating diagnostic parameters and the decision-making block, a block of specified diagnostic parameters connected to the third input of the comparison block, memory block, information output block, train speed determination block, output connected to the corresponding input of the block for calculating diagnostic parameters and decision-making block, output connected to the input of the memory block and information output block, serially connected base of rolling stock types, determination block type of mobile unit and a counter of mobile units, the output of a decision-making unit connected to the corresponding input, three magnetic sensors, a wheel pair counter, with each of the receivers located in a separate box, its sensitive element is installed at the height of the axle box unit of the wheel pair of a moving train car, the boxes are installed evenly along the railway track on a given section of the track, at least six on each side of the railway track opposite each other, one of the sides of each box facing the railway track is equipped with a curtain, the opening mechanism of which is located in the box itself and is connected control input to the output of the box curtain control unit, each box has a thermostating system installed, the input/output of which is connected to the output/input of the thermostat system control unit, with the first and second magnetic sensors installed on opposite sides of the track on the rails opposite the first and last receiver, respectively, and outputs are connected to the corresponding inputs of the block for determining the type of mobile unit and the wheel pair counter, the output connected to the corresponding inputs of the block for calculating diagnostic parameters, the decision-making block, the block for determining the type of mobile unit and the block for determining the speed of the train, the third magnetic sensor is placed at a given distance from the last the acoustic signal receiver is directly on the rail and its output is connected to the input of the box shutter control unit (RU 89053 U1, B61K9/00, 2009.11.27).

The disadvantage of the known technical solution is the inability to detect wheel defects in moving train cars.

The technical result of the proposed invention is to increase the reliability, accuracy of diagnosis and identification of faults in the wheels of passing rolling stock in real time.

The technical result is achieved in that the system for monitoring defects in wheel pairs of rolling stock contains a single-mode fiber-optic cable laid in the ground at a given distance from the railway track, one side of which is made with a sealed plug, and the other side is connected to the input/output of a coherent reflectometer, the other output of the processing unit connected to the input, and connected to the fiber of the fiber-optic cable, at least one sensitive element, including k turns of single-mode optical fiber, mounted on a sensitive membrane on the rear wall of the horn mounted on a support at a given distance from the rail and height from the level embankment of the railway track with the direction of the central axis of the horn to the point of contact of the wheel tread surface with the rail surface, while using a horn with geometric dimensions that ensure the maximum concentration coefficient of sound wave energy on the sensitive membrane, and the number of turns of single-mode optical fiber is selected depending on the width of the coherent pulse optical radiation from a reflectometer laser.

To carry out precise location reference, the sensitive element of the system is installed next to a picket or overhead power pole.

To increase the reliability and accuracy of diagnostics and event identification, the sensitive element of the system is installed at a distance from the rail butt joints.

The system is illustrated by drawings in Figs. 1-3.

Figure 1 shows a diagram of the implementation of a system for monitoring acoustic influences using a sensitive element; in fig. 2A shows an example of calculating the horizontal sweep of a horn, and FIG. 2B shows an example of determining the dimensions of the horn of the sensitive element; Fig. Figure 3A shows reflectograms of the acoustic signal of the passage of rolling stock (TS) without a wheel defect, Fig. 3B shows the change in the acoustic signal in the presence of a defective wheel.

The system for monitoring defects in wheel pairs of rolling stock contains a single-mode fiber-optic cable 1 laid in the ground at a given distance from the railway track, one side of which is made with a sealed plug 2, and the other side is connected to the input/output of a coherent reflectometer 3, the other output of which is connected to input of the processing unit 4, and connected to the fiber of the fiber-optic cable at least one sensitive element, including k turns of single-mode optical fiber, mounted on the sensitive membrane 6 of the rear wall of the horn 7, mounted on a support at a given distance from the rail and height from the level embankment of the railway track with the direction of the central axis of the horn 7 to the point of contact of the wheel tread surface with the rail surface, while using a horn 7 with geometric dimensions that ensure the maximum concentration coefficient of sound wave energy on the sensitive membrane 6, and the number of turns 5 of single-mode optical fiber 1 is selected in depending on the pulse width of the coherent optical radiation of the reflectometer laser 3.

In this case, the sensitive element of the system is installed next to a picket or a contact network pole.

The sensitive element of the system is installed at a distance from the rail butt joints.

The system for monitoring defects in wheel pairs of rolling stock works as follows.

When a train passes the location of the sensitive element, the energy of the acoustic wave 8 from the noise source (Fig. 1), entering the horn 7, which is structurally designed to eliminate or minimize the possibility of back reflection outward of part of the acoustic energy, as a result of re-reflections of acoustic waves from the walls of the resonator part horn 7, the energy of the acoustic wave 8 is focused (accumulated) on the sensitive membrane 6 (acoustic diaphragm) of the rear wall of the resonator part of the horn 7. The energy of the acoustic wave, focused by the resonator of the sensitive element, causes vibration vibrations 9 of the sensitive membrane 6 together with the turns 5 of single-mode optical fiber attached to it , the free ends of which are included in the fiber of the fiber-optic cable 1 (FOC) by optical welding or through optical couplings.

The source of coherent radiation 10 (laser) of the reflectometer 3 generates direct optical radiation 11, which, through the optical circulator 12, FOC 1, passes through turns 5 of single-mode optical fiber attached to the sensitive membrane 6 of the horn 7 of the sensitive element. As a result, acoustic waves from the noise source have an oscillatory and vibrational effect on the sensitive membrane 6, which, being attached to the turns of optical fiber, causes changes in the reflected laser radiation corresponding to the vibrations of the membrane 6, resulting in the formation of an additional source of reflected optical signal in each turn 5 of the fiber-optic cable, which, as a result of summation, amplify the power signal by k times, where k is the number of turns of the optical fiber.

The appearance of vibrations from a defective wheel, the frequency-amplitude spectrum of which introduces corresponding, pre-classified changes in the flow of Rayleigh reflection from turns 5 of the optical fiber, is converted into changes in the power of reflected laser radiation, which are determined using a reflectometer 3. Next, the reflected radiation 13 enters through the circulator 12 to the input of the photodetector 14 for processing the signal of reflected radiation and converting optical energy into electrical energy, from the output of which the converted electrical signals are sent to the input of block 15 for preliminary digital processing of the reflected signal and presenting them in the form of reflectograms 16. Reflectograms 16 with changes in optical radiation as a result of acoustic influence , obtained during pre-processing 15, are fed to the input of processing block 4 in order to detect signs of an event, their subsequent analysis, and make a decision based on the analysis results about the presence or absence of a wheel defect based on a comparison of the results obtained with the standards obtained at the training stage. After this, at the output of processing block 4, an event message 17 is generated, which is transmitted to the information exchange network to provide access to consumers. In addition, the reflectometer 3 is connected by another input to the output of the processing unit 4 for calibration (not indicated in Fig. 1). The installation of reflectometer 3 is carried out to ensure the temperature conditions during its operation.

Geographical reference of the location of the sensitive element (location of installation of the horn 7 of the sensitive element) can be done by reference to the nearest picket or overhead power pole. Geographical coordinates are referenced using the picket (post) number + distance from it in meters.

Since the rail joint for the sensitive element is a pronounced source of interference, it is better to place it as far as possible or in the middle of the continuous section of the track.

The system for monitoring defects in wheel pairs during the passage of a rolling stock can be used to identify in real time events from the list of defects in wheels (such as slider, weld, etc.), car bogies (jamming), rail surface (in the area of effect of the installed horn), and other events related to monitoring the condition of stationary objects and rolling stock, which have a significant impact on the safety of railway traffic, the transportation of passengers and cargo.

In fig. 2A shows an example of calculating the horizontal sweep of a horn, and FIG. 2B provides an example of determining the size of the horn of a sensitive element with a calculated coefficient of concentration of sound wave energy on the membrane equal, for these dimensions, to 2.641.

To calculate the parameters of the horn, the following values are fixed:

- horizontal width of the horn;

- initial horn depth - this parameter is necessary to set the angle of reflection of the sound wave;

- range to a point sound source.

To calculate the horizontal geometric dimensions of the horn, carry out the following calculations (Fig. 2A):

1) determine the angles α, β, γ :

; ; ;

2) calculate the ratios:

; ;

;

; ;

;

3) determine the total depth of the conical part of the horn: .

To calculate the vertical geometric dimensions of the horn, carry out the following calculations (Fig. 2B):

1) determine the height horn, based on the condition of ensuring vertical scanning:

with the same initial data: And :

; ; ;

; ;

; .

2) determine the total depth of the conical part of the horn: .

The basis for defect detection using the Rayleigh effect is the cognitive graph shown in FIG. 3 (upper two parts), and reflectograms shown in the lower part of FIG. 3. Reflectograms characterize changes in the amplitudes of the cognitive graph signal at certain points in time, which are marked on the cognitive graphs (Fig. 3) by vertical lines.

When conducting laboratory experiments, as well as in natural conditions at the training ground of JSC Russian Railways, the operating mock-up was placed at a given distance from the outer rail and at a height of 40 cm from the embankment level with the direction of the central axis of the horn to the point of contact of the wheel tread surface with the rail surface. The calculations and tests carried out showed that installing the horn at a height of 40 cm is optimal from the point of view of maximum concentration of the signal power by the horn when determining defects that appear during the interaction of the wheel and the rail.

In fig. Figure 3 shows the results of a full-scale experiment on a section of a railway track, in which 50 m of optical fiber was rolled up in the sensitive element and secured to the horn membrane, in which every 2 meters of the physical length of the fiber corresponds to one control section on the reflectogram, in this example, having a conditional numbering from 277 to 302 (X scale). This preliminary division is associated with the detection of defects in the form of a jammed wheel pair on a passing railway station, which during experimental studies was represented by a diesel locomotive and three freight gondola cars. The left column A shows the results of processing PS signals for the case when there are no wheel defects: at the top is a cognitive graph of reflectograms of the original signals; in the middle of column A - a cognitive graph after processing the original signal using mathematical methods of predistorting the signal generated by a reflectometer; in the lower part of column A - a graph of the passage of a PS without a defect in the form of a reflectogram obtained after processing the reflectometer signal, which corresponds to the area selected for experimental research (No. 298) of the sensitive element.

On the right side of Fig. Figure 3B shows the results of signal processing from the PS, which included a car with a jammed wheelset: on top - a cognitive graph of reflectograms of the original signals; in the middle of column B is a cognitive graph with the results of applying algorithms for mathematical processing of the original signal; The lower graph of column B is a graph of the passage of a PS with a defect in the form of a reflectogram obtained after processing the reflectometer signal in a selected area (No. 298) of the sensitive element.

As a result of a comparative analysis of these graphs, we can conclude that the proposed system for detecting defects in PS wheels is high. The column graphs of Fig. 3A show that by analyzing the acoustic signal, it is possible to obtain data on wheelsets, number of cars, train length, speed, etc. The graphs of the column of Fig. 3B display the change in the acoustic signal in the presence of a defective wheel in the composition, according to the characteristics of which it is possible to detect the presence of jammed wheelset at the PS, accurately determine the point of skidding (the point of contact of the tread surface of the jammed wheelset with the rail) when it slips rail joints.

The high sensitivity of the proposed detection system is ensured by introducing operations of predistortion of signals generated both by the distributed FOD itself, using the Rayleigh effect, and by the reflectometer. In the first case, the effect of pre-distortion of a group seismoacoustic wave formed in a distributed water-wave is implemented due to mechanical “markers”, and in the second - on the basis of mathematical methods of constructive finite field theory (CTFT) and adaptive nonlinear filtering (ANF).

The experimental studies carried out show that the proposed system can be used not only to solve important problems that are associated with diagnosing the technical condition of wheelsets and rails, but also actual problems of determining the location of speed, length and integrity of the railway.

Thus, the proposed invention provides a significant increase in the sensitivity of the proposed wheel defect detection system by increasing the signal-to-noise and signal-to-interference ratios in fiber-optic measurement data (FOI).

Claims (3)

1. A system for monitoring defects in wheel pairs of rolling stock, containing a single-mode fiber-optic cable laid in the ground at a given distance from the railway track, one side of which is made with a sealed plug, and the other side is connected to the input/output of a coherent reflectometer, the other output connected to input of the processing unit, and connected to the fiber of the fiber-optic cable at least one sensitive element, including k turns of single-mode optical fiber, mounted on the sensitive membrane of the rear wall of the horn mounted on a support at a given distance from the rail and height from the level of the embankment of the railway track with the direction of the central axis of the horn to the point of contact of the wheel tread surface with the rail surface, while using a horn with geometric dimensions that ensure the maximum concentration coefficient of sound wave energy on the sensitive membrane, and the number of turns of single-mode optical fiber is selected depending on the pulse width of coherent optical laser radiation reflectometer. 2. The system according to claim 1, characterized in that the sensitive element is installed next to a picket or a contact network pole. 3. The system according to any one of paragraphs. 1 and 2, characterized in that the sensitive element is installed at a distance from the rail butt joints.