GB2023835A - Transcription of numbers representative of geometrical defects of railway tracks - Google Patents

Abstract

Transcription of numbers representative of the amplitudes (a) of the defects on railway track sections (k) traversed in succession in which - these amplitudes are measured by means of a measurement device (1); - they are recorded for each section in a memory (9); - they are distributed among classes of increasing importance for each section, by means of a classification unit (10); - their number is counted in each of these classes by means of a counter (11); - from the results of this counting there are eliminated the numbers of a value less than or equal to a selected minimum (as shown, zero) by means of a discriminator (12); - the remaining numbers are transcribed onto a document (14) by means of a printer (13) to positions appropriate to the class of amplitudes and the section to which they belong. <IMAGE>

Description

SPECIFICATION Process and apparatus for the statistical transcription of at least one category of geometrical defects of railway tracks and document resulting from said transcription The present invention relates to a process and apparatus for the statistical transcription of at least one category of geometrical defects of railway tracks and a document resulting from said transcription, which are intended for the making of diagnoses concerning the condition of the track, for the preparing of short-term, medium-term and long-term maintenance work programs for the qualities required by said condition, as well as for verifying such work.

Recourse to the geometrical measurements of two lines of rail of the railway track in order to program the track maintenance work is a recent innovation. It makes it possible to avoid the needless work inherent in the old methods of programming, which provided for the carrying out of this work in accordance with rigid periodic cycles covering all of the maintenance operations, and thus to save time and money.

On the other hand, in order to be usable in this sense, these geometrical measurements must be transcribed in a form which is as representative as possible of the change in the geometrical state of the tracks so as to facilitate their examination and analysis.

In the recent past, and still today in certain railway networks, this examination and analysis were effected and are still effected on basis of graphical records giving an analog picture of the geometrical characteristics of the two lines of rail of the track and by comparing the results obtained with preestablished tolerances.

However, the method of examination and analysis based on graphical recordings is lengthy and requires highly qualified personnel since the picture given is deformed in amplitude and position to a greater or lesser extent depending upon the measurement apparatus employed. This personnel must therefore interpret this picture by reference to a so-called "transfer" function relating the input magnitude to the response magnitude, assumed known and directly usable, of the measurement apparatus employed. Then, as this picture is purely an analog image, this personnel must quantify the results by reference to a magnitude scale indicated on the graph and then classify them in different classes of increasing importance and by characteristic rail sections before being able to establish an optimum programming of this work.

At present, a process and a transcription device are known which, as defined in the preambles of Claims 1 and 2, make it possible automatically to carry out this quantification and classification. The document resulting from this transcription, defined in the preamble of Claim 3, is in the form of a table the numerical values of which representing the number of geometrical defects of each class cover the entire are contained within the limits of the number of classes and the number of measurement runs or sections.

This transcription greatly simplifies the task of the personnel assigned to the analysis of the geometrical measurements of the track but it does not, on the other hand, supply a picture of the change in said measurements. A rapid visual interpretation of such change and of its critical values is therefore not possible on basis of such a document and this is prejudicial to a rapid interpretation of the results which it presents in this purely digital form.

As characterized in Claims 1, 2 and 3, the object of the invention is to solve this problem by imparting to the distribution of the numerical values representative of the number of defects of each class of amplitudes on the face of the document resulting from the transcription, an analog picture of their development, measurement section after measurement section.

The solution proposed, by eliminating values less than or equal to the minimum selected, is simple and shows visibly the envelope of the values of amplitudes greater than this minimum of defects, counted and classified for each measurement section, the shape of this envelope being significant of the development of the said amplitudes section by section.

The accompanying drawing illustrates one particular point of the transcription process of the invention and shows by way of example one embodiment of the device for the carrying out thereof as well as a document resulting from this transcription.

Figure 1 is a graph referring to the transcription process.

Figure 2 is a block diagram of the transcription device.

Figure 3 is a partial view of the document resulting from the transcription.

The example given refers to the surface defects of the travel surface of a line of rails and, in order to simplify understanding, the minimum selected number of defects is considered to be zero. However, it is to be understood that the process is applicable to all other defects in the geometry of the track such as defects in longitudinal and transverse level as well as defects in straightness, and the minimum number selected may be other than zero or express, for instance, a percentage of the defects measured in each section.

The curve C of the graph shown in Figure 1 is representative of the change in amplitude of the surface defects of the travel surface of a line of rails 2, shown in Figure 2, traversed and sensed continuously by a measurement car 3 pulled by a vehicle (not shown) and equipped with an electronic sensor 4which supplies an analog signal which is proportional to the amplitude of said defects, said car being part of a measurement device 1.

In this graph, the amplitudes of the defects measured are read in abscissas along the horizontal axis 0 a and the position of these defects with respect to a point of origin in spa > e is read in ordinates along the vertical axis Ok.

In order to obtain the digital value of the amplitudes of the defects measured, the electronic sensor 4 is connected to an analog-digital code 5. The restitution of the measurement signals as a function of the space traversed by the measurement car 3 is obtained by a magnetic proximity detector 6 providing, due to the action of a gear wheel 7 rigidly connected with a wheel of the measurement car 3, one pulse every x units of linear displacement, for instance in the present case every 100 mm.This value x corresponds in the graph to the such multiples of the graduations of the axis Ok of the spaces traversed,4nd the graduations of the amplitudes on the axis 0 a are representative of classes of increasing amplitudes measured from 1 to 9 which are selected in accordance with their dynamic effects on the track and the rolling stock, each of which classes may cover equal or different differences in amplitude. These classes of amplitudes are understood for the given example from 0.1 mm for class 1 to 1 mm for class 9.

In orderto transcribe by the process of the invention the results of the measurements effected by means of the measurement device 1,the latter is connected to a processing circuit 8 comprising: - A memory 9 for recording the amplitude of the defects measured on the successive measurement sections of given length, here corresponding toWhe graduations of the axis of the spaces traversed Ok and each of which comprises 10 measurements of amplitudes spaced by the value x.

- A classification unit 10 for distributing the said amplitudes within a plurality of classes of increasing importance, which in this case are the classes marked from 1 to 9 which have already been described.

- A counter 11 for counting their number in each of said classes and for each of the measurement sections 0.1 - 0.2 - 0.3, etc.

- A discriminator 12 for eliminating all the num bers resulting from the counting whose significant value is less than or equal to the selected minimum, in this case equal to zero.

- A printer 13 for transcribing the remaining numbers on a detailed support document 14, Figure 3, readable along two perpendicular axes one of which k is representative of the succession of measurement sections and the other of which, a, is representative of the succession of the classes of amplitudes of increasing importance.

By means of the graph of Figure 1, it is clearly noted that this document 14 represents, for each measurement section and with respectto only certain of the classes of amplitudes a number representing the number of defects whose ampli tude is contained within said classes, to the exclu sion of the other classes to which none of the ten defects measured belong, and which, on the docu ment resulting from the known process, is indicated by zero sincethe minimum selected is zero.

Thus, for instance, it is seen that for the path 0.1 0.2 the ten defects measured have amplitudes belonging to classes 5, 6 and 7 exclusively and that only their number in each of these classes is transcribed on the document, while in the known document the succession of numbers transcribed for this path would be: 0,2*000034300 and for the following paths: 0,3*022600000 0,4*022222000 0,5*000001540 0,6*000005500 0,7*005230000 0,8*143200000 By comparison of these two forms of transcription there is clearly noted the advantage of the one in accordance with the invention which has already been pointed out, showing the envelope of the values of amplitudes of the defects measured, counted and classified for each measurement section, the shape of this envelope being significant of the development of the said amplitudes section by section.

Variants can be utilized.

For example, the measuement device 1 may be of a different type based on an accelerometer measurement or else on a combination of linear and accelerometric measurement, as is done in this field, provided that the measurement values supplied are significant of the amplitude of the defects measured.

The memory 9, the classification unit 10, the counter 11 and the discriminator 12 of the processing circuit can be replaced by a processor programmed to carry outthe same functions.

Finally, the document 14 may contain other transcriptions relating to the second line of rail as well as to other categories of defects, depending on the number of maintenance actions or numbers of controls desired.

Claims (6)

CLAIMS:

1. A process for the statistical transcription of at least one category of geometrical defects of railway tracks in which one measures and memorizes a sampling of the said defects on track sections of given length traversed in succession, in which these defects are classified in accordance with their amplitude and, for each of these sections, in a plurality of classes of increasing importance, and in which their number is counted in each of said classes and the numbers thus obtained are transcribed for each measurement path on a support document which is readable along two perpendicular directions, one of which is representative of the succession of measurement sections and the other of which is representative of the succession of classes of importance in their increasing order, characterized by the fact that only numbers having a significant value greater than a selected minimum are transcribed.

2. An apparatus for the statistical transcription of at least one category of geometrical defects of railway tracks comprising a measurment device (1) for measuring the amplitude of a sampling of the said defects and a processing circuit (8) for processing the measurement magnitudes including a memory (9) to record the amplitude of the defects which is measured on the track sections of given length which are traversed in succession, a classification unit (10) for distributing the said amplitudes within a plurality of classes of increasing importance, a counter (11) to count the number in each of the said classes and for each of the said measurement sections, and a printer (13) to transcribe the numbers thus obtained for each measurement section on a support document (14) which can be read along two perpendicular directions, one of which is representative of the succession of measurement sections and the other of which is representative of the succession of the classes of importance in their increasing order, characterized by the fact that the printer (13) is connected to the processing circuit via a discriminator (12) in order to eliminate from the transcription all numbers representing numbers of defects the significant value of which is less than or equal to a selected minimum.

3. A support document as the statistical transcription of at least one category of geometric defects of railway tracks comprising a plurality of numbers each significant of a number of defects the amplitude of which is contained within a class of given importance and which are counted on track sections of given length which are traversed in succession, and on which the said numbers are distributed along two perpendicular directions one of which is representative of the succession of measurement sections while the other is representative of the sucession of the classes in their increasing order, characterized by the fact that for each measurement section it comprises only numbers whose significant value is greater than a selected minimum.

4. A process for the statistical transcription of at least one category of geometrical defects of railway tracks substantially as herein described.

5. An apparatus for the statistical transcription of at least one category of geometrical defects of railway tracks constructed and arranged to operate substantially as herein described with reference to and as illustrated in the accompanying drawings.

6. A support document as the statistical transcription of at least one category of geometric defects of railway tracks substantially as herein described with reference to and as illustrated in Figure 3 of the accompanying drawings.