EP3162958B1 - Method for measuring and assessing the geometry of a railway track - Google Patents

Description

Field of the invention

The invention belongs to the field of metrology, more specifically the control of railway infrastructure to ensure the safety and comfort of traffic on these rail infrastructure.

The invention relates more particularly to obtaining and analyzing geometrical data relating to a railway track of a railway infrastructure, in particular leveling and dressing.

State of the art

Measuring the geometry of railways is a particularly heterogeneous field of railway science, as much because of the diversity of the techniques and means of measurement used as for the purpose of the measurements.

Indeed, while the quantification and evaluation of the quality of railway geometry is necessary to ensure the safety and comfort of rail traffic on the infrastructure inspected, it finds an increasingly important application during maintenance and major work operations for purposes of preparation, constitution of input data for studies, provisional recording, or reception for entry into the maintenance domain.

It is becoming more and more important to sustain the infrastructures against aging but also to control them in order to ensure that their characteristics remain in conformity with the maintenance standards in force, whether from the installation of new works or during the construction activities. maintenance.

It is equally important to ensure the proper execution of this work. Moreover, these monitoring correspond in addition to a legal or regulatory obligation according to the type of network considered. For example, on the French National Rail Network, the control of the geometry of the lane of high-speed lines is exerted every 15 days as opposed to every 6 months to a year on conventional network lines and this, according to the National Instructions established by SNCF Infra as Infrastructure Manager on behalf of Réseau Ferré de France. On urban networks, whose control is assumed by a deconcentrated State technical service, the inspection step is annual.

• le nivellement du rail de la file intérieure et celui du rail de la file extérieure ;
• le dévers ;
• le gauche ;
• le dressage du rail de la file intérieure et celui du rail de la file extérieure ;
• l'écartement.

Measuring the geometry of a railway is usually characterized by a set of mathematical parameters. These parameters, seven in number, are as follows:

• the leveling of the rail of the inner line and that of the rail of the outer line;
• the slope;
• the left;
• the railing of the inner line and the rail of the outer line;
• the spacing.

By rail of the inner line is meant the rail located on the side of the entrance in case of double lane or the rail of the queue of the small radius.

Left rail means the rail opposite to the previous rail.

• un premier domaine D1 où les longueurs d'onde sont comprises entre 3 et 25m, qui ne concerne que la sécurité,
• un deuxième domaine D2 où les longueurs d'onde sont comprises entre 25m et 70m, qui concerne la sécurité et le confort
• un troisième domaine D3 où les longueurs d'onde sont comprises entre 70m et 150m, qui concerne uniquement le confort.

The spacing and left settings are mainly used for security purposes only. These are the parameters to be controlled at a minimum, especially on the service and industrial tracks. For lanes of the main network, it is imperative to have complete parameters such as leveling and training that relate to both safety issues but also comfort. However, the delimitation between safety and comfort is not really based on this or that parameter but more on the spectrum of defects in that it is the frequency components of the measured parameters (leveling, dressing) that excite the vehicles' own modes. Thus, concerning the leveling and the training, one generally separates the domains of wavelengths included between three domains:

• a first domain D1 where the wavelengths are between 3 and 25m, which concerns only security,
• a second area D2 where the wavelengths are between 25m and 70m, which concerns safety and comfort
• a third area D3 where the wavelengths are between 70m and 150m, which concerns only the comfort.

The most common form of track geometry measurement is that of inspection of national networks with heavy means of car type or ream of measurement. These periodic inspections, usually every six months, are carried out under load (that is to say, the measurement takes place under the real load that the railway usually supports when passing rail traffic) and aim to monitor the overall quality of the geometry. track and to detect and quantify defects in order to preserve the safety and comfort of traffic but also allow the conditional preventive maintenance that is triggered from the identification of threshold exceedances standardized by one or more of the measured parameters. These operation triggers are intended, inter alia, to prevent irreversible damage to the components of the pathway occur.

Among others, there is the high-speed train, called IRIS 320®, consisting of an entire train of a high-speed train.

The principle applied in this high speed train is the inertial measurement. The inertial measurement advantageously allows the direct measurement of the leveling and the absolute alignment of the track. This measurement therefore makes it possible to obtain the absolute profiles of the channel directly.

The term absolute profile refers to the leveling and / or dressage of the railway.

The measurement principle is based on the evaluation of the position of the rail in the vertical and lateral directions with respect to an inertial reference given by gyroscopes and accelerometers. At a minimum, an accelerometer and a gyroscope per reference axis are required.

An inertial reference unit is mounted on a dimensionally stable beam, for example of the box or bogie type. Added to this are additional laser measurement systems for determining the position of the inertial unit relative to the rails. The measurement of the distance from the inertial unit to the rails is necessary in order to evaluate the position of the rails in the inertial reference. In fact, the measurement of joint tracks or of channels with numerous gaps is tricky because the laser measurement systems drop at the joints or gaps.

Such a non-contact inertial measuring device allows a measurement of all the parameters of the track geometry up to a speed of movement on the train track of 360 km / h.

However, such a device has some significant disadvantages that are the difficulty of managing the shortcomings of railways, for example at joints and in switches, the particularly high cost of a single machine or the need for a minimum speed of traffic on the track of the measuring car of at least 60 km / h.

The inertial measurement, unlike a rope measurement (with or without contact) is dependent on the speed of the vector that embeds the measurement system. Indeed, the estimation of the displacements of the inertial reference is based on measurements of acceleration and rotation from which one can find said displacement values. It is easy to understand that at low speed, the acceleration levels recorded are low and therefore insufficient to correctly obtain displacement values. The correspondence between the spectrum of the input of the inertial system and the transfer function of the accelerometers that partially compose it can only be done at speeds of the order of that indicated above. In any case, it is not possible to obtain measurements for steps or slow steps.

The scope of measurement cars equipped with such a non-contact inertial measurement system is therefore limited.

Beside this unique system, we can also mention Mauzin cars whose measurement principle is a rope principle with contact. Equipped with eight measurement wheels for taking up motion in vertical directions and three pairs of feeler rollers for measurements in the horizontal direction, these cars are the reference for measuring in France for conventional lines. The transfer function of such machines has the interesting particularity of being close to the unit for the usual wavelengths close to the terminals of the domain D1. The bandwidth at -3dB of the system has been cleverly defined so that defects, whose frequencies correspond statistically to those found on the conventional network, are restored in full size.

However, such cars are particularly expensive to build but especially to maintain because of the very great mechanical rigor of maintenance that must be done, both on the vector but also on the grip and mechanical transmission of the movement. The operation of such a car can only be conceived at the level of national or multinational companies because of the important costs related to the training and the traction of the special measuring trains including car of measurement, cars for the weight brake and locomotives framing the convoy for its reversibility. Programming track geometry recording runs is therefore several months in advance, and there is no flexibility for specific local needs. These cars thus exercise an annual or semiannual control with no possibility of adaptation of the steps of measurement to the particular need of the local maintainers (according to work in progress etc.).

Alongside these measurement cars is a set of needs that is more clearly identified by the fact that it is understood that the inspections of the measuring cars are planned years in advance and that their small number does not allow a employment corresponding to all the needs of those responsible for the maintenance of railways. They have more or less specific needs, such as site validation, tracking identified defects, and so on. which may take place between two major inspections.

Thus, over the last decade, the rail market has developed, mainly thanks to the progress of instrumentation and microcomputer technology, lighter and manual measurement devices. These measuring devices are in the form of small trolleys pushed by hand, commonly referred to as lorries in the railway environment.

• première catégorie : les lorries de contrôle dont les fonctionnalités sont uniquement de mesurer et contrôler les paramètres usuels de sécurité que sont le gauche et l'écartement. Ces lorries sont de petites dimensions, de l'ordre de 1 à 2 mètres, donc facilement transportables. Ces lorries sont des améliorations directes des dispositifs manuels, du type règles à devers et écartement, pour effectuer des courses de mesure jusqu'à quelques centaines de mètres et réaliser, à la différence des dispositifs manuels, la mesure en continu. Les besoins couverts sont essentiellement ceux de la petite inspection, de la vérification limitée à ces deux paramètres de travaux effectués, en attendant le passage de la voiture de mesure. A titre d'exemple, on peut citer le lorry de mesure Diamond's® de la société Geismar ;
• deuxième catégorie : les lorries destinés de manière quasi exclusives au chantier et visant à faciliter le travail historique des géomètres topographes. Il s'agit d'engins de petites dimensions, très légers (de l'ordre de 40 kg), poussés à la main et recevant généralement des mires de géomètre, des cibles de théodolite ou des stations totales. Soit le lorry est visé depuis une station totale fixe au sol, soit la station totale est installée sur le lorry et vise des mires fixes au sol ou sur des points fixes. Ces systèmes sont destinés à guider des bourreuses où permettre des récolements de projet de géomètres. C'est surtout durant la phase même de la pose des rails que ces systèmes présentent une utilité ou pour les lignes à grande vitesse. Ces systèmes nécessitent alors l'implantation de goujons géo-référencés sur des points fixes, ces goujons étant référencés dans des repères absolus de type nivellement général de la France (NGF) ou Lambert étendu. Ces systèmes, couteux à poser et entretenir, ne sont pas généralisés à l'ensemble du réseau.. A titre d'exemple, on peut citer le lorry Amberg GRP5000 ou encore le Hergie de la société Rhomberg. Ces deux lorries portent la mire. Les données fournies ne sont cependant pas exploitables facilement et directement pour la maintenance car elles ne peuvent pas être comparées aux seuils de maintenance prédéfinis.
• troisième catégorie : les lorries de mesure relative, destinés à mesurer le nivellement et le dressage. Ces lorries mesurent essentiellement des flèches sur des cordes matérialisées par des poutres. En raison de la difficulté de rendre les mesures indépendantes des défauts de gauche, que ce soit par soucis d'ergonomie, ou par difficulté mécanique, les bases de mesures sont particulièrement limitées avec un maximum atteint à 5m. Il s'agit par exemple des lorries Plasma de la société Rhomberg ou bien du lorry EMA de la société Vögel und Plöstcher.

Three main categories of lorries stand out:

• first category: control lorries whose functions are only to measure and control the usual security parameters that are the left and the distance. These lorries are small, of the order of 1 to 2 meters, so easily transportable. These lorries are direct improvements of the manual devices, of the type rules to devers and gauge, for perform measurement runs up to a few hundred meters and, unlike manual devices, perform continuous measurement. The needs covered are essentially those of the small inspection, the verification limited to these two parameters of work done, pending the passage of the measuring car. By way of example, mention may be made of the Diamond's® measurement lorry from Geismar;
• second category: the lorries destined in a manner almost exclusive to the site and aiming to facilitate the historical work of the topographers. They are small, very light machines (around 40 kg), pushed by hand and generally receiving surveyors, theodolite targets or total stations. Either the lorry is targeted from a fixed total station on the ground, or the total station is installed on the lorry and targets fixed sights on the ground or on fixed points. These systems are intended to guide tampers where to allow the survey of projectors of geometers. It is especially during the very phase of laying the rails that these systems have utility or for high speed lines. These systems then require the implantation of studs georeferenced on fixed points, these studs are referenced in absolute benchmarks of general leveling type of France (NGF) or extended Lambert. These systems, expensive to install and maintain, are not generalized to the entire network .. For example, we can mention the lorry Amberg GRP5000 or the Hergie from Rhomberg. These two lorries carry the test pattern. However, the data provided can not be used easily and directly for maintenance because they can not be compared to the predefined maintenance thresholds.
• third category: relative measurement lorries, intended to measure leveling and training. These lorries measure mainly arrows on ropes materialized by beams. Due to the difficulty of making measurements independent of the defects of left, either for the sake of ergonomics, or by mechanical difficulty, the bases of measurements are particularly limited with a maximum reached with 5m. These are, for example, Plomma lorries from Rhomberg or LORRY EMA from Vögel und Plöstcher.

These three types of lorries only partially fulfill the need that may exist between measurement steps of inspection cars or waiting for the first pass after laying or renewal of lanes.

The lorries of the third category only measure on short measurement bases (of the order of 1 to 2 meters) and can only measure a "local" profile of the track, ie the defects low wavelengths. Beyond that, the vast majority of them only provide raw arrows, without recoloring, that is to say without eliminating the influence of the transfer function.

In addition, the measurements made on these lorries are performed only on one rail at a time, and therefore do not allow to properly take into account the curves and against curves.

Another disadvantage for lorries of the ^2nd class is that the topographic measurement informs above all on a positioning in x, y, z of the axis of the way. In this way, we do not obtain any information that can be easily identified by the field, in particular because of the abstraction of the formalism of the representation, far from the formalism useful for the maintenance track and specified in the standard NF EN 13848-1 . The measurement is discretized, generally every 5 to 10 meters, which allows to appreciate only the components of wavelength at least higher than these values, ie 10-20 meters minimum.

These disadvantages are all the more visible during the temporary reconstruction operations of the railway works. Indeed, during these tests, the need, which does not meet these lorries, corresponds to a measurement made from light gear, easily derailed between the different trains of construction site so as not to hinder the traffic, which can provide real time all the parameters of the track geometry and enable measurement on larger or absolute measurement bases to better quantify long-term defects.

The results of measurement of the majority of these lorries are not in conformity with the expectations of the norms NF EN 13848-4 in force since 2010. Indeed, it is at the level of the formalism of the data, with the level of the exhaustiveness of the measured parameters or the correction of the influence of transfer functions, the number of deviations from the standard renders them unsuitable for use in line with the expectations of this series of European standards.

The major disadvantage of these different lorries beyond the disadvantages described above lies in the impossibility of providing data compatible with the expected work of the operations of the work or preparation of future operations. The lorries of the second category, the topographic lorries, can not in addition provide useful information that can be detected by the eye in real time.

Presentation of the invention

The object of the present invention is to overcome the drawbacks mentioned above and in particular to the lack of devices for measuring all of the track geometry parameters, more specifically the leveling and the dressing parameters, in the D1 and D2 domains of lengths d. wave between 3 and 70 meters.

The present application describes for this purpose a measuring device (or lorry) whose arrangement of the constituent elements and the properties make it possible, via a suitable signal processing method, to obtain all of the seven above-mentioned channel geometry parameters. in relative and absolute terms. The parameters of the track geometry are advantageously obtained over wavelength ranges of between 3 and 70 meters, areas where very few measuring devices exist. These ranges of wavelengths between 3 and 70 meters are defined so as to be compatible with the domains D1 and D2 defined by the standard NF EN 13848-1, in force since 2010. The patent application US 3,604,359 A describes a known measuring device.

The parameters measured by the demand measuring device advantageously make it possible to carry out track and trace studies of railways. They allow in particular to be placed in conformity with the formalism of the input data of such studies: arrows obtained on bases of elongated measurements (of at least 20m), elongated or absolute leveling on domains D1 and D2.

The parameters measured and obtained with the demand measuring device are advantageously in accordance with the expectations of the standard NF EN 13848-4.

• un chariot de guidage,
• deux bras de mesure s'étendant de part et d'autre du chariot de guidage, destinés à s'étendre dans une direction longitudinale X des rails de la voie ferrée,
• deux chariots de stabilisation, chaque chariot de stabilisation étant relié au chariot de guidage par un bras de mesure,
• des moyens de mesure d'au moins un paramètre géométrique.

The device for measuring geometric parameters of a railway line according to the application comprises:

• a guide carriage,
• two measuring arms extending on either side of the guide carriage, intended to extend in a longitudinal direction X of the tracks of the railway,
• two stabilization trolleys, each stabilization trolley being connected to the trolley by a measuring arm,
• means for measuring at least one geometrical parameter.

Such a measuring device advantageously makes it possible to roll on the two rails of the railroad track and to record, via the measuring means, the seven geometrical parameters of the track, without interdependence of the parameters between them. The measuring device advantageously makes it possible to measure vertical and horizontal arrows intended for estimating the leveling or the dressing of the railway.

In a manner known per se, the terms arrows refer to the mathematical notion of orthogonal distance between a string stretched between two points and a third point. In the railway field, the two extreme points are in contact with the same rail and the third point, also in contact with the same rail, is located either equidistant from the two extreme points, or at any distance between the two extreme points. The arrow is said to be horizontal when the rope is stretched with respect to a side of a mushroom of the rail. The arrow is said to be vertical when the rope is stretched relative to a tread of the rail.

According to preferred embodiments, the request also satisfies the following characteristics, implemented separately or in each of their technically operating combinations.

In preferred embodiments, the two stabilizing carriages are made so as to be insensitive to the left of the railway.

In preferred embodiments, each measuring arm is integrally bonded to a stabilization carriage by a ball joint.

Preferably, in order to make the arrow measurement insensitive to the left of the railway, the ball joint is positioned in the immediate vicinity, ie as close as possible, of a rolling plane of a rail line, without touching said rail queue.

In preferred embodiments, each measuring arm is dimensioned and bonded with a measuring plate of the guide carriage so that the measurement of a horizontal arrow is independent of the track cant.

• une plateforme à trois ensembles de roulage, destinée à être positionnée sur une première file de rail de la voie ferrée,
• un quatrième ensemble de roulage, destiné à être positionné sur une seconde file de rail de la voie ferrée,
• une traverse destinée à relier la plateforme au quatrième ensemble de roulage.

La demande est également relative à un procédé d'estimation d'un profil absolu d'une voie ferrée à partir de signaux de flèches obtenus par le dispositif de mesure suivant au moins l'un de ses modes de réalisations. La demande se distingue de la demande de brevet WO 2004/029825 A1 de par sa capacité à tenir compte de la fonction de transfert réelle d'un dispositif de mesure physiquement réalisé, tel que construit avec ses imperfections mécaniques et ses contacts non ponctuels, et non de la basique fonction de transfert du principe de mesure 3 points.In preferred embodiments, the stabilization trolley comprises:

• a platform with three rolling sets, intended to be positioned on a first rail line of the railway,
• a fourth rolling assembly, intended to be positioned on a second rail line of the railway,
• a cross member for connecting the platform to the fourth rolling assembly.

The application also relates to a method for estimating an absolute profile of a railway track from arrows signals obtained by the measuring device according to at least one of its embodiments. The application is different from the patent application WO 2004/029825 A1 because of its ability to take into account the actual transfer function of a physically realized measuring device, as constructed with its mechanical imperfections and non-point contacts, and not the basic transfer function of the 3-point measurement principle.

The method comprises a step of applying an impulse response filter to the arrow signals, said impulse response filter being characterized by a polynomial function whose coefficients are determined from a reverse transfer function of said device. measured.

According to preferred embodiments, the request also satisfies the following characteristics, implemented separately or in each of their technically operating combinations.

In preferred embodiments, the impulse response filter is an infinite impulse response filter.

In preferred embodiments, the impulse response filter is a finite impulse response filter.

• une sous-étape d'obtention des valeurs numériques des modules et arguments d'une fonction de transfert caractérisant le dispositif de mesure,
• une sous-étape d'inversion numérique des modules et de prise de l'opposé des arguments de ladite fonction de transfert,
• une sous-étape d'une estimation polynomiale de la fonction de transfert inverse à partir des modules et arguments de la fonction de transfert inverse,

lesdits coefficients de la fonction polynomiale du filtre à réponse impulsionnelle correspondant aux coefficients de l'estimation polynomiale de la fonction de transfert inverse.In preferred embodiments, the estimation method comprises a preliminary step of determining the coefficients of the polynomial function of the impulse response filter. Said step comprises:

• a substep of obtaining the numerical values of the modules and arguments of a transfer function characterizing the measuring device,
• a substep of numerical inversion of the modules and taking the opposite of the arguments of said transfer function,
• a sub-step of a polynomial estimation of the inverse transfer function from the modules and arguments of the inverse transfer function,

said coefficients of the polynomial function of the impulse response filter corresponding to the coefficients of the polynomial estimation of the inverse transfer function.

The determination of the coefficients makes it possible to produce a signal processing filter that really takes into account the measuring device and not the measuring principle. The patent application WO 2004/029825 A1 uses the expression of a pure 3-point measuring device, whereas a physical measuring device has a transfer function which is not necessarily exactly that corresponding to a pure 3-point principle. Indeed, there are always several wheels in contact with the rail, with a certain wheelbase, so there are not three point relations with the rail. In addition, the connections and the transmission of the movement therefore require wheelbases between parts, modifying somewhat the transfer function with respect to a device measuring 3 pure points.

In preferred embodiments, in order to obtain the transfer function of the measuring device and not of the measuring principle, the numerical values of the modules and arguments of the transfer function characterizing the measuring device are obtained from a kinematic modeling of the measuring device. Kinematic modeling takes into account the very constitution of the measuring device and the non-punctual character of the real links.

In preferred implementation modes, the preliminary step of determining the coefficients of the polynomial function of the impulse response filter comprises a sub-step of frequency windowing of the inverse transfer function, in which the estimation sub-step polynomial of the inverse transfer function from the modules and arguments of the inverse transfer function is performed for each window and wherein the arrow signal is windowed frequently before application of the impulse response filter. This sub-step advantageously makes it possible to considerably improve the quality of the interpolation aimed at defining the module and the argument of the transfer function. The application also relates to a method for obtaining an arrow signal based on virtually elongated measurement from arrow signals obtained by a measuring device according to at least one of its embodiments.

The method comprises a step of applying an impulse response filter to the arrow signals, said impulse response filter being characterized by a polynomial function whose coefficients are determined from an inverse transfer function of said measuring device. and a transfer function characterizing a second larger measurement base measurement device.

In preferred embodiments, the impulse response filter is an infinite impulse response filter.

In preferred embodiments, the impulse response filter is a finite impulse response filter.

• une sous-étape d'obtention des valeurs numériques des modules et arguments d'une fonction de transfert caractérisant le dispositif de mesure,
• une sous étape d'obtention des valeurs numériques des modules et arguments d'une fonction de transfert caractérisant le deuxième dispositif de mesure de base de mesure plus grande,
• une sous-étape d'inversion numérique des modules et de prise de l'opposé des arguments de ladite fonction de transfert,
• une sous étape de multiplication par le module de la fonction de transfert du deuxième dispositif et de sommation de l'argument de la fonction de transfert du deuxième dispositif,
• une sous-étape d'estimation polynomiale du rapport des fonctions de transfert caractérisant le deuxième dispositif et le dispositif de mesure à partir des rapports des modules et de la différence des arguments des fonctions de transfert.

In preferred embodiments, the method comprises a preliminary step of determining the coefficients of the polynomial function of the impulse response filter. Said step comprises:

• a substep of obtaining the numerical values of the modules and arguments of a transfer function characterizing the measuring device,
• a sub-step of obtaining the numerical values of the modules and arguments of a transfer function characterizing the second larger measurement base measuring device,
• a substep of numerical inversion of the modules and taking the opposite of the arguments of said transfer function,
• a substep of multiplication by the module of the transfer function of the second device and summation of the argument of the transfer function of the second device,
• a sub-step of polynomial estimation of the ratio of the transfer functions characterizing the second device and the measurement device from the reports of the modules and the difference of the arguments of the transfer functions.

The coefficients of the polynomial function of the impulse response filter correspond to the coefficients of the polynomial estimation of the impulse response filter.

The determination of the coefficients makes it possible to produce a signal processing filter that really takes into account the measuring device and not the measuring principle.

In preferred embodiments, in order to improve the signal processing method by allowing a polynomial estimation as close as possible to the inverse transfer function, each measurement measuring arm has a length such that the arrow catch is in an asymmetric chord configuration and such that a transfer function of such a measuring device has zero for any frequency component as well as no abrupt variation of slope.

In preferred embodiments, the two measuring arms have a total length such that the cutoff of the transfer function at the long wavelengths is pushed back so as to obtain limited attenuations for frequency components whose wavelength is close to a high bound of a domain D2.

The invention relates to a method for estimating an absolute profile of a railway track from arrow signals obtained by a measuring device.

The method comprises a step of applying an impulse response filter to the arrow signals, said impulse response filter being characterized by a polynomial function whose coefficients are determined from an inverse transfer function of said measuring device. .

In preferred embodiments, the impulse response filter is an infinite impulse response filter.

• une sous-étape d'obtention des valeurs numériques des modules et arguments d'une fonction de transfert caractérisant le dispositif de mesure,
• une sous-étape d'inversion numérique des modules et de prise de l'opposé des arguments de ladite fonction de transfert,
• une sous-étape d'une estimation polynomiale de la fonction de transfert inverse à partir des modules et arguments de la fonction de transfert inverse,

lesdits coefficients de la fonction polynomiale du filtre à réponse impulsionnelle correspondant aux coefficients de l'estimation polynomiale de la fonction de transfert inverse.In preferred embodiments, the impulse response filter is a finite impulse response filter. The estimation method comprises a preliminary step of determining the coefficients of the polynomial function of the impulse response filter. Said step comprises:

• a substep of obtaining the numerical values of the modules and arguments of a transfer function characterizing the measuring device,
• a substep of numerical inversion of the modules and taking the opposite of the arguments of said transfer function,
• a sub-step of a polynomial estimation of the inverse transfer function from the modules and arguments of the inverse transfer function,

said coefficients of the polynomial function of the impulse response filter corresponding to the coefficients of the polynomial estimation of the inverse transfer function.

In preferred modes of implementation, in order to obtain the transfer function of the measuring device and not of the measuring principle, the numerical values of the modules and arguments of the transfer function characterizing the measuring device are obtained from a kinematic modeling.

In preferred implementation modes, the preliminary step of determining the coefficients of the polynomial function of the impulse response filter comprises a sub-step of frequency windowing of the inverse transfer function, in which the estimation sub-step polynomial of the inverse transfer function from the modules and arguments of the inverse transfer function is performed for each window and wherein the arrow signal is windowed frequently before application of the impulse response filter. The application also relates to a method for obtaining an arrow signal on a basis of measurement that is virtually elongated from arrow signals obtained by a measuring device.

The method comprises a step of applying an impulse response filter to the arrow signals, said impulse response filter being characterized by a polynomial function whose coefficients are determined from an inverse transfer function of said measuring device. and a transfer function characterizing a second larger measurement base measurement device.

In preferred embodiments, the impulse response filter is an infinite impulse response filter.

In preferred embodiments, the impulse response filter is a finite impulse response filter.

• une sous-étape d'obtention des valeurs numériques des modules et arguments d'une fonction de transfert caractérisant le dispositif de mesure,
• une sous étape d'obtention des valeurs numériques des modules et arguments d'une fonction de transfert caractérisant le deuxième dispositif de mesure de base de mesure plus grande,

• une sous-étape d'inversion numérique des modules et de prise de l'opposé des arguments de ladite fonction de transfert,
• une sous étape de multiplication par le module de la fonction de transfert du deuxième dispositif et de sommation de l'argument de la fonction de transfert du deuxième dispositif,
• une sous-étape d'estimation polynomiale du rapport des fonctions de transfert caractérisant le deuxième dispositif et le dispositif de mesure à partir des rapports des modules et de la différence des arguments des fonctions de transfert.

La demande est également relative à un dispositif de mesure dans lequel chaque bras de mesure présente une longueur telle que la prise de flèche soit en une configuration de corde asymétrique et telle qu'une fonction de transfert d'un tel dispositif de mesure ne comporte de zéro pour aucune composante fréquentielle ainsi qu'aucune variation brusque de pente. Ainsi, le procédé de traitement du signal est considérablement amélioré en permettant une estimation polynomiale au plus près de la fonction de transfert inverse.In preferred embodiments, the method comprises a preliminary step of determining the coefficients of the polynomial function of the impulse response filter. Said step comprises:

• a substep of obtaining the numerical values of the modules and arguments of a transfer function characterizing the measuring device,
• a sub-step of obtaining the numerical values of the modules and arguments of a transfer function characterizing the second largest measuring device of larger measurement,

• a substep of numerical inversion of the modules and taking the opposite of the arguments of said transfer function,
• a substep of multiplication by the module of the transfer function of the second device and summation of the argument of the transfer function of the second device,
• a sub-step of polynomial estimation of the ratio of the transfer functions characterizing the second device and the measurement device from the reports of the modules and the difference of the arguments of the transfer functions.

The application also relates to a measuring device in which each measuring arm has a length such that the arrow catch is in an asymmetric rope configuration and such that a transfer function of such a measuring device does not include zero for any frequency component as well as no abrupt variation of slope. Thus, the signal processing method is considerably improved by allowing a polynomial estimation as close as possible to the inverse transfer function.

In preferred embodiments, the two measuring arms have a total length such that the breaking of the transfer function at long wavelengths is pushed back so as to obtain limited attenuations for frequency components whose length of wave is close to a high bound of a domain D2.

Presentation of figures

• La figure 1, représente une vue en perspective du dispositif de mesure selon l'invention,
• La figure 2 représente une vue latérale du dispositif de mesure de la figure 1,
• La figure 3 représente un agrandissement du dispositif de mesure au niveau d'un chariot de guidage,
• La figure 4 représente une vue en perspective de la première plateforme du chariot de guidage,
• La figure 5 représente une vue latérale de la première plateforme du chariot de guidage,
• La figure 6 représente une vue latérale opposée de la première plateforme du chariot de guidage,
• La figure 7a représente une vue de dessus d'un plateau de mesure de la première plateforme du chariot de guidage destiné à recevoir les bras de mesure du chariot de guidage,
• La figure 7b représente une coupe transversale de la figure 7a au niveau d'une double chape,
• La figure 8 représente une vue de dessus d'un chariot de stabilisation,
• La figure 9 représente une vue en perspective du chariot de stabilisation de la figure 8,
• La figure 10 représente une vue de coté du chariot de stabilisation,
• La figure 11 représente un schéma synoptique du procédé d'estimation d'un profil absolu d'une voie ferrée à partir de signaux de flèches obtenus par un dispositif de mesure selon l'invention.

The invention will now be more specifically described in the context of preferred embodiments, which are in no way limiting, represented on the Figures 1 to 11 , in which :

• The figure 1 , represents a perspective view of the measuring device according to the invention,
• The figure 2 represents a side view of the measuring device of the figure 1 ,
• The figure 3 represents an enlargement of the measuring device at level of a guiding carriage,
• The figure 4 represents a perspective view of the first platform of the carriage,
• The figure 5 represents a side view of the first platform of the carriage,
• The figure 6 represents an opposite side view of the first platform of the carriage,
• The figure 7a is a top view of a measuring plate of the first platform of the carriage for receiving the measuring arms of the carriage,
• The figure 7b represents a cross-section of the figure 7a at the level of a double screed,
• The figure 8 represents a top view of a stabilization trolley,
• The figure 9 represents a perspective view of the stabilization trolley of the figure 8 ,
• The figure 10 represents a side view of the stabilization trolley,
• The figure 11 represents a block diagram of the method for estimating an absolute profile of a railway track from arrow signals obtained by a measuring device according to the invention.

Detailed description of the invention

An exemplary embodiment of a measuring device 1 according to an embodiment of the invention is now described in detail and illustrated by the Figures 1 to 10 .

The invention is described in the case of a railway 5 of a national network, normal gauge, or 1435mm, but the invention is also applicable to all types of railroads, including metric gauge tracks.

A railway line 5 consists of two rows of rails 6, 7 facing each other, the spacing of which is kept constant by fastening on crosspieces 8.

For the entire description, we define a reference XYZ, of center 0, in where the X axis represents the longitudinal direction of the railway, the Y axis represents the direction transverse to the rails, that is to say in the direction of the sleepers, and the Z axis represents the vertical, perpendicular axis to both X and Y axes.

The measuring device 1 is suitable for measuring the seven parameters of the geometry of the channel. More specifically, the measuring device 1 is suitable for measuring the leveling and the dressing of each rail line 6, 7 by an arrow measurement via the three-point rope measuring principle.

The training measurement is obtained from the measurement of a horizontal arrow, that is to say an arrow measured in an XOY plane.

The leveling measurement is obtained from the measurement of a vertical arrow, that is to say an arrow measured in an XOZ plane.

• un chariot de guidage 10,
• deux bras de mesure 20 s'étendant de part et d'autre du chariot de guidage 10,
• deux chariots de stabilisation 30, chaque chariot de stabilisation 30 étant relié au chariot de guidage par un bras de mesure.

The measuring device 1, intended to be installed on the two rows of rails 6, 7 of a railway line 5, comprises:

• a guide carriage 10,
• two measuring arms 20 extending on either side of the guide carriage 10,
• two stabilizing carriages 30, each stabilizing carriage 30 being connected to the guide carriage by a measuring arm.

The guide carriage 30

• une première plateforme 11 destinée à être positionnée sur une première file de rail 6,
• une seconde plateforme 12 destinée à être positionnée sur une seconde file de rail 7,
• une barre de liaison 13 rigide destinée à relier les deux plateformes 11, 12, et destinée à être positionnée selon un axe transversal Y, parallèlement aux traverses.

The guide carriage 30 comprises, as illustrated in the Figures 3 to 7b :

• a first platform 11 intended to be positioned on a first rail line 6,
• a second platform 12 intended to be positioned on a second rail line 7,
• a rigid connecting bar 13 for connecting the two platforms 11, 12, and intended to be positioned along a transverse axis Y, parallel to the crosspieces.

• un premier ensemble, dit de roulage 110, destiné à prendre appui et à faire rouler la première plateforme 11 sur la première file de rail 6,
• un second ensemble, dit de liaison 111, destiné à relier la première plateforme 11 aux bras de mesure 20.

The first platform 11 , illustrated figure 4 to 7b , includes:

• a first assembly, said rolling 110, intended to support and roll the first platform 11 on the first rail line 6,
• a second assembly, called link 111, for connecting the first platform 11 to the measuring arms 20.

Throughout the description, by two integral parts or two parts connected / joined together, means two mechanically linked parts allowing at least one degree of freedom.

By degree of freedom in a connection is meant a relative movement independent of a part with respect to another authorized by this connection.

The running assembly 110 comprises at least one wheel 1101 intended to bear against the top of the mushroom of the first rail line, called the running surface 62. In a preferred embodiment, illustrated in FIG. figure 6 two wheels 1101 are supported on the first rail line 6 in order to give stability to the guide carriage 10 which thus rests on three wheels 1101 and is therefore insensitive to the left of the track. The two wheels are spaced from each other, along the longitudinal axis X, by such a distance that the wheelbase formed between the two wheels 1101 can easily allow the crossing of the gaps of the crossing parts of the switches. .

Support roller trains 1102 are intended to be positioned against an inner side 63 of the mushroom 61 of the first rail line 6, located opposite the mushroom 71 of the second opposite rail line 7. In a preferred embodiment, illustrated on the figure 4 two sets of support rollers 1102 bear against the first rail line 6, one set of rollers per wheel.

In an exemplary embodiment, each support roll train 1102 comprises three support rollers in order to be able to easily cross the gaps of the rails, whether at the rail joints, at the level of the expansion devices and so on. The two roller trains 1102 are spaced from each other along the longitudinal axis X by a distance such that this distance is greater than the length of an existing maximum gap in the track.

The running assembly 110 further comprises magnetic means 1103 for keeping the wheel 1101, and therefore the first platform 11, against the rail 6, to avoid derailments of said platform.

In a nonlimiting embodiment, the magnetic means 1103 are magnetized blocks, preferably two in number.

The magnetic means 1103 are intended to be arranged against a flank of the mushroom of the first rail line 6. In the nonlimiting example of the figure 4 , the magnetic means are arranged against the inner side 63 so as to present no hindrance in the crossing of the crossing apparatus and level crossing decks. This inner side 63 being guaranteed to be free, since it is on him that comes to bear the roll of the wheels of railway vehicles.

• un premier bloc, dit plateau de mesure 1111, destiné à assurer la continuité rigide des deux bras de mesure 20, sur lequel va venir se solidariser les deux bras de mesure, afin de ne former qu'une seule et même base de mesure,
• un second bloc, dit embase de mesure 1112, sur lequel va venir se fixer en liaison pivot le plateau de mesure 1111, ledit second bloc roulera dans des moyens de guidage 131 portés par la barre de liaison 13.

The link assembly 111 includes, illustrated on the Figures 4 to 6 :

• a first block, said measuring plate 1111, intended to ensure the rigid continuity of the two measuring arms 20, on which the two measurement arms will be joined, so as to form only one and the same measurement base,
• a second block, called measuring base 1112, on which will be fixed in pivot connection the measuring plate 1111, said second block will roll in guide means 131 carried by the connecting bar 13.

The measuring plate 1111 has a substantially rectangular parallelepiped shape of length L (along the transverse axis Y) greater than a width of the rail. The measuring plate 1111 has a width such that a distance between the vertical end plates of the link arms is sufficiently short for the measuring device to remain comparable to a three-point rope measuring system.

The measuring plate 1111 is rigid enough to be insensitive to the bending that can be experienced by the guide carriage 10.

The measuring plate 1111 is advantageously made of an aluminum or treated steel material.

The measuring plate 1111 comprises, at the level of longitudinal flanks 11111, clevises 11112, Figures 7a and 7b . Each longitudinal flank 11111 has a double clevis. In total, the measuring plate 1111 has four screeds 11112. In each double screed is mounted without play a shaft 11113 carried by rolling bearings mounted tight. Each shaft 11113 is secured respectively to a measuring arm 20 described later.

The measuring base 1112 has a substantially rectangular parallelepiped shape.

In an exemplary embodiment, the measuring base 1112 has a width substantially identical to the width of the measuring plate.

The measuring base 1112, at a first face, is integral with a so-called lower face 11114, the measuring plate 1111. Only a rotation along the vertical axis Z between the measuring plate 1111 and the base 1112 is permitted. The aim is to enable the guide carriage 10 to form an angle with the measuring arms (always aligned) when the measuring device 1 enters or leaves a curve of the railway line 5.

The measuring base 1112, at a second face, opposite the first face, is in sliding connection with the connecting bar 13. Said measuring base 1112 comprises two roller trains which roll on the guide means 131 carried by said link bar.

The guide means 131 are intended to allow the lateral displacement, along the transverse axis Y, of the first platform 11.

In a preferred embodiment, the guide means 131 are two parallel guide rails, preferably of treated steel, inserted into said connecting bar.

The rollers have a shape complementary to the shape of the guide rails.

The shape of the rollers is defined so that said rollers hold the measuring base 1112 secured to the connecting bar 13 so as to allow rotation along the vertical axis Z, while allowing transverse axis translation Y. This transverse axis translation Y allows, via the measuring plate 1111, in pivot connection of vertical axis Z with this measurement base 1112 but integral with it in this same vertical direction, the measuring arms 20 to materialize the rope as soon as possible. when a curve is created on the track.

The wheelbase between the two roller trains is important particular and must be a number of times the value of the spacing between the two guide rails on which these roll trains roll and this to prevent the measuring base can slide in a direction other than parallel to said rails of guide. The importance of this parallel guidance is made necessary by the desire to avoid any non-normal forces to the measuring arms and thus to promote possible bending.

The minimization of bending makes it possible to make the measurement of horizontal arrows for training by the measuring device 1 accurate and faithful, but above all to make this measurement totally independent of the tilt parameter and thus to measure the training of the tracks even in the ends. the extent of the slope, that is to say, in a steep curve, up to 220mm.

In conclusion, the integral connection between the connecting bar 13 and the first platform 11 of the carriage is only a translation transverse axis Y. A translation X horizontal axis is impossible because there is no play between the rollers and the respective guide rails 131. A vertical axis translation Z is impossible because the rollers and the respective guide rails are of complementary shapes. The complementary shape of the rollers and respective guide rails and the absence of play prevents the pitch of the measuring device, or prevents rotation along the transverse axis Y. A rotation along the horizontal axis X and the vertical axis Z is impossible because the two roller trains are separated by a predefined wheelbase.

The second platform 12 comprises a rolling assembly 120, as for the first platform 11, intended to support and roll the second platform 12 on the second rail line 7.

The rolling assembly 120 comprises at least one wheel 1201 intended to rest on the rolling plane 72 of the second rail 7. In a preferred embodiment, illustrated in FIG. figure 1 a single wheel 1201 is supported on the rail.

A support roll train 1202 is intended to be positioned against an inner side 73 of the mushroom 71 of the second rail 7, located opposite the mushroom 61 of the first rail 6.

In a nonlimiting embodiment, the support roll train 1202 comprises three support rollers.

The rolling assembly 120 further comprises magnetic means (not shown) for keeping the wheel 1201, and therefore the second platform 12, against the second rail 7, to avoid derailments of said second platform.

In an exemplary embodiment, the magnetic means are a single magnetized block.

The magnetic means are intended to be arranged against a flank of the rail head.

Measuring arms 20

Each measuring arm 20 is likened to a beam sufficiently rigid so as to resist torsion and bending during the displacement of the measuring device on the railway.

Each measuring arm 20 comprises a core 21 of length L _b predefined having, at longitudinal ends 22, a reinforcing plate 23, 24 and intended to ensure connection with the guide carriage 10.

The measuring arms 20 are intended to be positioned, when the measuring device 1 is placed on the track 5, so that their webs 21 are in the longitudinal axis X and the reinforcing plates 23, 24 in the axis transverse Y.

A reinforcing plate, called the first outer plate 23, of each measuring arm 20 comprises first connecting means 231 intended to be secured to the measuring plate 1111 of the connection assembly 111 of the first platform 11 of the guide carriage 10.

In a preferred embodiment, the first connecting means 231 are a jaw having a substantially parallelepipedal shape, one face 2311, intended to be positioned facing the shaft 11113, is recessed in a triangular manner, so that the positioning the jaw 231 (triangular recess) on the shaft 11113 (substantially circular shape) provides a three-point connection, thus an absence of play between them, which ultimately minimizes the measurement errors of the horizontal and vertical arrows.

In one embodiment of a first external plate 23, said first outer plate comprises stiffeners 232 at a face 233 of the first reinforcing plates 23 vis-à-vis the connection assembly.

In a non-limiting example of the invention, the stiffeners 232 are ribs.

Preferably, the first outer plate 23 has a length, along the transverse axis Y, substantially equal to the length L of the measuring plate 1111 of the guide carriage 10.

The second reinforcing plate, called the second outer plate 24, of each measuring arm 20 comprises second attachment means 241 with the stabilizing trolley 30.

In one embodiment of a second outer plate 24, said second outer plate comprises stiffeners 242 at a face 243 of the second outer plate opposite to the face bonded to the core of the measuring arm.

In one embodiment of a core 21 of a measuring arm 20, the core 31 has a triangular lattice-type structure with a choice of spacing between the tubes making up the trellis that make them distant from the neutral fiber of the trunk. 'soul.

In an exemplary embodiment, the core 31 is a right triangular base prism formed by an assembly of tubes in the form of a lattice, of width (along the transverse axis Y) less than the length of the first outer plate. The core 31 further comprises a strut 211 to limit the torsion.

In another embodiment, the core 21 is any parallelepiped formed by an assembly of tubes in the form of a lattice, of width (along the transverse axis Y) substantially equal to the length of the first plate.

Preferably, in order to minimize the bending generation, each measuring arm 20 is made in one piece.

Each measuring arm 20 is fixed integrally respectively to a shaft 11113 mounted in a double yoke 11112. This assembly serves to form the interface with the first outer plates 23 of the measuring arms. The first outer plates 23, on the side of the carriage, each comprise two jaws 231, preferably treated steel, which comes to rest on two shafts 11113, preferably treated steel, carried by a double yoke. The bond thus formed is purely three points, therefore without possibility of games. These double clevises carry shafts mounted without clearance, the jaws 231 disposed on the first outer plates 23 of the measuring arms are positioned and maintained always on the same face of each double clevis, each by a system of flanges 26 and locusts 27, illustrated figure 6 , ensuring the setting and the maintenance in position and this, never to have a zero offset of the arrow measurement.

The single degree of connection between the measuring arms 20 and the guide carriage 10 is a transverse axis rotation Y. This single rotation is possible via the principle of the jaw which encloses the axes held by the double clevises. There is no other rotation or translation along any of the three axes.

The distance between the axis of the two double clevises on each side of the measuring plate must be large enough for the guidance to be rigorous in order to avoid any bending. This distance must be greater than a fraction of the length of each measuring arm. This distance plays an important role in obtaining an overall rigidity of the measurement cord represented by the two measurement arms connected at the level of this measuring plate.

In a nonlimiting embodiment, such a distance is 7.4% of the length of the longest measuring arm.

Preferably, the measuring arms are made of a light material, for example aluminum.

Stabilization trolleys 30

The stabilizing carriages 30 are substantially identical. The description will be made only on a stabilization trolley.

• une plateforme 31 destinée à être positionnée sur la première file de rail 6, comportant trois ensembles de roulage 311 en série le long de l'axe longitudinal X,
• un quatrième ensemble de roulage 32 destiné à être positionné sur la seconde file de rail 7,
• une traverse rigide 33 destinée à relier la plateforme 31 au quatrième ensemble de roulage 32.

A stabilization trolley 30 comprises, as illustrated in the Figures 8 to 10 :

• a platform 31 intended to be positioned on the first rail line 6, comprising three rolling assemblies 311 in series along the longitudinal axis X,
• a fourth rolling assembly 32 intended to be positioned on the second rail line 7,
• a rigid cross member 33 for connecting the platform 31 to the fourth rolling assembly 32.

The three rolling assemblies 311a, 311b are spaced from each other, along the longitudinal axis X, by a distance such that the distance formed between the so-called central rolling assembly 311a and the two so-called external rolling assemblies 311b allow, via rods rods, to prevent the derailment of the measuring device, the moment necessary for detachment of the integral magnets so-called rolling assembly being even larger than the spacing between these sets of rolling is large.

The central rolling assembly 311a is secured to the second outer plate 24 of a measuring arm 20.

In a non-limiting example of the invention, the central rolling assembly 311a is secured to the second outer plate 24 by a bracket provided with a bore which carries the bearing into which the axis of the wheel engages.

The three rolling assemblies 311a, 311b of the platform 31 of the stabilization trolley 30 each comprise at least one wheel 3111 intended to rest on the rolling plane 62 of the first rail 6. In a preferred embodiment of a set of rolling, illustrated on the figure 10 a wheel is leaning on the rail.

Support roller trains 3112 are intended to be positioned against the inner side 63 of the mushroom 61 of the first rail line 6. In a preferred embodiment, illustrated in FIG. figure 10 two sets of support rollers bear against the first rail line.

In an exemplary embodiment, the support roll train of the three central rolling assemblies comprises three support rollers in order to easily cross the gaps of the rails.

The roller trains 3112 are spaced from each other, along the longitudinal axis X, by a distance such that this distance is greater than the length of an existing maximum gap on the track.

The three rolling assemblies 311a, 311b further comprise magnetic means 3113 intended to keep the wheel 3111 pressed, and by therefore the platform 31, against the first rail line 6, to avoid derailments of said platform.

In a nonlimiting embodiment, the magnetic means 3113 are magnetized blocks, preferably two in number for the central rolling assembly 311a and the number of one for the other two sets of rolling 311b.

The magnetic means 3113 are intended to be arranged against a flank of the rail head. In the example of the figure 9 , the magnetic means are arranged against the inner side 63 so as to present no hindrance in the crossing of the crossing apparatus and level crossing decks. This interior flank being guaranteed to be free, since it is on him that comes to bear the roll of the wheels of the railway vehicles.

The fourth rolling assembly 32 is intended to support and roll on the second rail line 7.

The fourth rolling assembly comprises a wheel 321 intended to rest on the rolling plane 72 of the second rail line 7.

The rigid cross member 33 connects the wheel 3111 of the central rolling assembly 311a to the wheel 321 of the fourth rolling assembly 32.

The rigid cross member 33 is positioned so as to meet along the transverse axis Y, when the measuring device 1 is in place on the railway track.

The two outer rolling assemblies 311b are connected to the rigid cross member 33, via a beam 34. A first end of the beam connecting said beam to a sliding mobile frame 35 on the cross member is a pivot connection. There is thus no rotation relative to the rigid crossbar 33, but a degree of freedom in translation along the transverse axis Y and a degree of freedom in translation along the vertical axis Z. Said sliding mobile frame 35 is the interface with the rigid cross member 33 and allows not to impact the horizontal deflection measurement by the large wheelbase between the two sets of external rollings 311b. This sliding mobile frame 35 also makes it possible to render the behavior of the stabilization carriage insensitive to the left of the track. Indeed, the left is the distance from one point to the planes formed by the other four. If there are only three wheel / rail contact points, two on a rail line and one in the opposite row, there can be no left. This movable frame, allows the stabilization trolley to have this embodiment by making the wheels of external rolling sets independent in the vertical and lateral planes of the wheels carrying the cross. A second end of the beam, opposite the first end, connecting the beam to the outer running assembly is a ball joint.

The rigid crossbar 33 has a slide connection 36 to which are integrally connected two pivoted rods 361, said two pivoted rods being integrally connected each to a beam.

The slide link 36 is intended to prevent the recesses or derailments of the wheel 321 of the fourth rolling assembly 32 of the second rail run 7 and to distort the measurements recorded by the measuring device. Such recesses or derailments could occur when the railway has a curve or simply when disturbing elements, such as pebbles, are on the rolling plane 72 of the second rail line 7.

Each pivoted connecting rod 361 is secured to an external rolling assembly 311b by a ball joint 37. The connection between a measuring arm 20 and a stabilization trolley 30 is therefore a ball joint, which allows rotation along the three axes X, Y and Z. There is no possible translation on said three axes.

The stabilization trolley 30 further comprises an elastic return means 38 connecting the slide connection to one end of the cross member located on the side of the fourth rolling assembly. This elastic return means advantageously makes it possible to keep the central rolling assembly 331a pressed against the first rail line 6.

The measuring device 1 also comprises a device for locating the odometric position (not shown) of the fixed points on the railway track.

The odometry device makes it possible to determine the measurement of a distance traveled on the track by the measuring device 1.

In a preferred embodiment, the odometry device comprises an incremental encoder for a gear wheel of the measuring device. In an exemplary embodiment, the odometry device is positioned on the wheel 1201 of the rolling assembly 120 of the second platform 12 of the guide carriage 10.

In another embodiment, the odometry device comprises an auxiliary location device, for example of the satellite type such as the so-called GPS system (Global positioning system). Such an auxiliary device makes it possible to prelocalize the measuring device on the track by ensuring an approximate absolute marking.

The measuring device 1 further comprises first measuring means (not shown) for measuring the left and right sides of the track 5.

The first means of measuring the devers are preferably an inclinometer for measuring an angle in the YOZ plane.

The first measuring means allow on the one hand the direct measurement of the devers of the railway and on the other hand the indirect measurement of the left, via a differential measurement of the devers.

In one embodiment, the inclinometer is positioned on the connecting bar 13 of the guide carriage 10.

In another embodiment, the inclinometer is positioned on the crossmember 33 of the stabilization trolley 30.

The measuring device 1 further comprises second measuring means (not shown) for measuring the gauge of the railroad track.

The second measuring means are preferably a linear displacement sensor intended to measure a variation in the spacing between the two rails.

Advantageously, the displacement sensor is positioned on the connecting bar 13 of the guide carriage 10, along the transverse axis Y.

In a nonlimiting embodiment, the displacement sensor is positioned on a so-called horizontal face of the connecting bar of the guide carriage, when the measuring device is in place on the railroad track in order to differentially measure the position of the measuring plate carrying the rolling elements and the connecting bar.

In an exemplary embodiment, the displacement sensor is connected to the connecting bar by centering studs and bolts.

Preferably, the displacement sensor is a magnetostrictive type sensor, for example the MKS sensor from TWK.

The measuring device 1 further comprises third measuring means 2 for the direct measurement of the horizontal arrow. The measurement of the horizontal arrow gives the information on the training of the first line of rail.

The dressing of the second rail line is advantageously determined from the measurement of the distance and that of the horizontal arrow of the first rail line.

The three trolleys (guide and stabilizer) are in contact with the first rail and the measuring arms materialize a rigid rope. The measuring device 1 is thus comparable to a three-point rope measurement system.

When the railway has a curve, there is a displacement along the transverse axis Y of the two rigid measuring arms 20 materializing the rope and secured by the measurement base of the guide carriage relative to the connecting bar of said carriage guidance. It is then possible to carry out a direct measurement of the horizontal arrow.

The third measurement means are preferably linear displacement sensors.

Advantageously, the displacement sensor is positioned on the connecting bar of the guide carriage, along the transverse axis Y.

Preferably, the displacement sensor is a magnetostrictive type sensor, for example the MKS sensor from TWK.

In a nonlimiting embodiment, the displacement sensor is positioned on the vertical face of the connecting bar of the guide carriage comprising the sliding means for measuring differentially the displacement of the measuring plate, integral with the two measuring arms.

The measuring base comprises on one of its vertical faces, a point of attachment, swiveled connecting rod with the linear displacement sensor.

Preferably, the displacement sensor is a magnetostrictive type sensor, for example the MKS sensor from TWK.

The measuring device further comprises fourth measurement means 3 for the indirect measurement of the vertical arrow. The measurement of the vertical arrow gives information on the relative leveling of the first line of rail.

The leveling of the second rail line is advantageously determined from the measurement of devers and that of the vertical arrow of the first rail line.

When the railway has differences in height, there is a displacement along the vertical axis Z of at least one of the two rigid measuring arms materializing the rope and secured by the measuring base of the guide carriage. It is then possible to carry out an indirect measurement of the vertical arrow, with the sign close, and consequently the relative leveling.

The fourth measurement means are preferably a linear displacement sensor.

Advantageously, the displacement sensor is positioned on the two measuring arms 20, near the first outer plates of said measuring arms, along the longitudinal axis X.

Preferably, the displacement sensor is a magnetostrictive type sensor, for example the MKS sensor from TWK.

Preferably, the displacement sensor is positioned on the furthest part of the running assembly of the guide carriage, that is to say the highest part relative to the railroad track when the measuring device is in position. place on the railway sight.

Ends of the measuring arms positioned on the side of the carriage have elements for fixing the two parts of a displacement sensor, as shown in FIG. figure 6 .

In a preferred embodiment, the fastening elements are threaded conical shafts, fitted into a tube of the mesh constituting the measuring arm previously drilled and conically bored.

In this embodiment, a threaded conical pin is mounted by arms measurement.

In an exemplary embodiment, the displacement sensor is secured to the threaded conical axis of a measuring arm, the movable portion of the displacement sensor is connected by a pivoted rod to the end of the threaded conical axis. fitted on the opposite measuring arm.

Obtaining the left and right parameters from the signals obtained with the first and second measuring means is of a type known per se and will not be described here.

The possibility of obtaining an absolute profile leveling (respectively training) from a relative measurement of the vertical (horizontal) arrow signal obtained with the fourth measurement means (respectively third measuring means) is of known type in itself.

In an exemplary embodiment, the absolute leveling profile (respectively the absolute profile of training) of the railway is obtained by means of a method of deconvolution of the vertical (respectively horizontal) arrow signal obtained with the fourth measurement means ( respectively third measuring means) and a convolution mask of the idealized measuring device.

However, this method has the disadvantage of not being able to make an estimate in real time. It also presents difficulties in obtaining absolute profiles of leveling (respectively of training) in particular at short wavelengths. The convolution mask, in the case of complex measuring devices, describes the measurement principle more than the actual measuring configuration of the measuring device and takes into account the realization of the kinematic links, etc. which make a measuring device is rarely of a pure three-point type.

In a manner known per se, a measurement of the 3-point type is an arrow measurement, that is to say a relative measurement intended to obtain an orthogonal difference between a materialization of a rope whose ends are in contact with the rail and a point of the rail located between these two ends. This point may be equidistant from the extremities, or at any distance.

In another embodiment, obtaining the parameters of Dressing and leveling from the signals obtained with the third and fourth measuring means is obtained from a treatment method as maintained described.

In a manner known per se, the term "dressage" designates the description of the layout of the railway in a horizontal plane, XOY, as presented on the figure 1 . This description can be done in two modes. Respectively, the term "leveling" refers to the description of the alignment of the railway in a vertical plane, XOZ, as shown on the figure 1 .

The first mode is constituted by a Cartesian representation, superimposing what the skilled person designates as a plane plot: a set of arcs of circles and alignments, connected to each other by clothoids or spiral branches of Cornu, which are sometimes replaced by approximations in cubic parabola; with the positioning defects of the railway. This first mode of description can be called absolute because it is done in an absolute reference, independent of any relative measuring device, finite dimension. This description can easily be done by a series of Fourier, in which each sinusoidal component participates in the overall description of the layout in plan or in length (according to whether we speak of dressage or leveling) as well as defects in lengths. wave more or less important. Those skilled in the art admit that a clear separation exists between the carrier of these "absolute" signals describing the pattern and the frequency components of higher frequencies, describing superimposed defects, more or less short.

This Cartesian plot, corresponding to a function y = e (x) where x is the curvilinear abscissa, along the railway (the curvilinear abscissa is usually equated with the Cartesian abscissa, as in the patent application WO 2004/029825 ) (respectively, z = e (x) for leveling). This function can be described by a Fourier series. It is therefore advantageous to represent the absolute profile of the railway by a sum of sinusoid.

The other mode of description is that characterized by horizontal and / or vertical arrows depending on whether the pattern is described in the horizontal and / or vertical plane. This signal of arrows, y2 = v (x), respectively z2 = v (x), is also a function of the curvilinear abscissa and mathematical relationships exist between said signal of arrows and the absolute signal referred to in the paragraph above.

It is also clear and obvious that this method of processing an arrow measurement signal, whether vertical or horizontal, can be adapted to any type of measuring device, other than that of the invention, adapted to the measuring said arrow.

A relative measurement device, whatever it is, is characterized by a transfer function. Said transfer function makes the connection between the amplitudes and phases of the frequency components of the input signal (representing the absolute measured channel profiles) and those of the frequency components of the output signal. These transfer functions are only used for modeling leveling and dressing parameters. The said leveling and dressing parameters are measured by the measuring device using a three-point type rope measurement principle corresponding to vertical and horizontal arrow measurements.

The method for processing the leveling and dressing measurement data (arrows) described is advantageously suitable for obtaining extrapolated arrows on elongated measurement bases or for obtaining signal components over length-of-length domains. precise wave for which their amplitudes have been restored to their true value, that is to say to obtain absolute profiles on specific bandwidths. Such bandwidths are, for example, the wavelength domains [3m; 25m] and [25m; 70m] known to those skilled in the art, or D1 and D2 as defined by the standard NF EN 13848-1. By measurement basis, we mean the materialization of the string of the measuring principle.

By arrows obtained on a long base, or contracted long base or elongated base, is meant, a signal of arrows obtained by post treatment on a virtually long basis. This "elongated" signal is obtained from a real physical signal measured on a real measurement basis of a device as described above. These arrows obtained on long base must correspond exactly to the arrows that one would really get with a rope measuring system of length equal to the length of the base being virtually long or elongated.

The method for estimating an absolute profile of a railway track from arrows signals obtained by the measuring device 1 comprises a step 50 of applying an impulse response filter 51 to the arrow signals, said impulse response filter characterized by a polynomial function whose coefficients are determined from an inverse transfer function of said measuring device.

The implementation of the method is actually two parameters that are leveling and dressing because they are two parameters constituting an indirect measurement approach of what is called leveling and dressing. Leveling is described either as a rope measure by arrows as well as by a Cartesian, absolute description.

The input of the measuring device is constituted by the "absolute" profile of the railway (said Cartesian description) which can be assimilated as seen to a signal with several sinusoidal components ranging from low to high frequencies.

The absolute profile of the railway can be represented as a sum of sinusoids of different wavelengths. The carrier is based on the long wavelength components related to the longitudinal profile. There are other superimposed sinusoids.

Assuming that the measuring device is a continuous and invariant linear device, its input can be represented as the sum of several signals and thus study the passage of components one by one through the impulse response filter constituted by the device. measurement. If we observe the passage of components one by one, we have at the input a sinusoidal signal characterized by its amplitude and its spatial wavelength.

The output is represented by the plot of v (x) which is a signal consisting of the arrows measured by the 3-point measuring device on this sinusoid or a signal of variation of height with respect to a mean plane, such as for example the MAUZIN system.

This output is in all cases sinusoidal also. A correct representation of the leveling (which is an amplitude relative to an average profile) can be given by drawing the leveling arrows taken over a certain length of rope.

This vision induces a distortion of reality.

This question also arises in the same way for dressage, only the plan is different.

A measurement system behaves like a filter that amplifies or attenuates the amplitudes of the input signal components according to their wavelength. To characterize the FT transfer function, the amplitude of the signal representing the vertical profile of the channel (absolute leveling profile), the horizontal profile of the channel (absolute profile of dressing), and the amplitude output, respectively, are input. of v (x), signal representing the drawing of the leveling arrows, respectively drawing of the training arrows.

The drawing of the leveling or dressing arrows is therefore a signal filtered from the absolute signals characterizing the railway track being measured.

The transfer function of a rope system or height difference type compared to the average height of a chassis (MAUZIN principle) will therefore be characterized by its module and its argument. The transfer function is a function of the wavelength of the components of the leveling or dressing defects and of the profiles in length and in plane (carriers). The knowledge of the transfer function makes it possible to know for each sinusoidal component the attenuation or amplification of the amplitude of the component (having the same wavelength) of the input signal as well as the phase shift.

The module is defined for each wavelength of the sinusoidal components as the ratio of the amplitude of the arrow signal (output signal) to the amplitude of the input signal (or absolute profile). The argument corresponds to a phase difference. For a given component of λ, therefore, FT (λ) = b / a where b is the amplitude of the wavelength component λ in the output signal and has the amplitude of the length component of wave λ in the input signal.

The module and the argument of the transfer function are an application of R in R, it is a function of λ (and the asymmetry of the measurement basis). This function is bounded since the module can vary only between 0 and 2. Since the chord serving as a measurement base is limited, it is understood that the 3-point type systems are high pass filters. Attenuation is therefore increasingly important at large and very long wavelengths. The module tends to 0 regardless of the type of system characterized by a transfer function. He tends more or less rapidly towards this 0.

As a reminder, three-point string measurement systems are considered linear continuous and invariant which allows to use the theorem of the superposition. Thus, the study of the systems is sinusoidal response by sinusoids. The sinusoidal response of a chord system to a sinusoidal input is compared to that of another larger basic measurement system.

pour une longueur d'onde donnée.For a given wavelength λ (x) is the measured input (one of the sinusoidal components of the absolute profile of the channel or a simplified representation of the channel) and E its amplitude; e (x) = E.cos (ω.x), with ω the spatial pulsation $\left(\omega =\frac{2\pi }{\lambda }\right)$

for a given wavelength.

It is easy for the amplitude of the output v (x) of the measuring device 1, called the signal of the arrows, to be V ₁ = FT ₁ .E where FT ₁ is the value of the module of the transfer function of the measuring device for this given λ.

• V₂=FT₂.E où FT₂ est la valeur du module de la fonction de transfert du dispositif de mesure pour une longueur d'onde λ₂ donnée.
• or, comme E=V₁/FT₁ on a bien V₂=(FT₂/FT₁).V₁.

Similarly, under the same conditions, for another measuring device of the same type but with a longer base:

• V ₂ = FT ₂ .E where FT ₂ is the value of the modulus of the transfer function of the measuring device for a given wavelength λ ₂ .
• however, since E = V ₁ / FT _1, we have V ₂ = (FT ₂ / FT ₁ ) .V ₁ .

Thus, again for given λ, to obtain the amplitude of the arrow signal of a long base system from a short base arrow signal, it is necessary to multiply the amplitude of the short base arrow signal by the ratio of the transfer function modules for this λ considered. For to obtain an "absolute" profile, multiply only by the inverse of the module of the transfer function of the measuring system.

By way of illustration, a numerical example is given below:
The input is characterized by its amplitude and its wavelength (E and λ), the amplitude of the input is the amplitude of the sinusoid with respect to the line of faith (0) is the amplitude compared at the average profile of the track. E = 10mm and λ = 25m.

The output or response of the measuring device 1 (symmetrical base 10m 2c = 10m) characterized by the module of its Transfer Function has a characteristic characteristic (generally different from that of the input) but the same wavelength. Its amplitude here is 0.69 * E is 6.9mm.

For the same input but with a symmetrical chord measurement system of 20m 2c = 20m, the amplitude of the output signal is: 1.81 * E is 18.1mm.

0.69 and 1.81 are the basic transfer function modules 10m and base 20m for this given λ (25m).

If we had multiplied the amplitude of the output signal 1 by 2.623 (= 1.81 / 0.69) we would have obtained 1.81mm is the amplitude of the output signal of the extrapolated rope system.

The general principle on which the method is based therefore consists in expressing for all wavelengths the ratio of the modules of the transfer function of the extrapolated system to the transfer function of the actual measuring device. Or the inverse of the module ratio, if you want to find the input of the measuring device, the absolute profile of the channel.

Thus, for an output signal, the sum of several sinusoids of different wavelengths, it will be necessary to multiply the amplitude of each component by the ratio of the modules for this given component (at a given λ). The total signal thus modified will represent the signal of arrows that one would obtain with an extrapolated rope system.

On the other hand, it is necessary to keep in mind that, in the general case, the correction of the amplitudes must also be accompanied by a correction of the phases.

• où ϕ₀, ..., ϕ_n est la phase,
• ω₀, ..., ω_n est la pulsation spatiale,
• v(x) est le signal de flèches issu de la mesure d'un profil de voie ferrée par un dispositif de mesure caractérisé par une Fonction de Transfert FT₁.

Is : $$\mathrm{v}\left(\mathrm{x}\right)={\mathrm{<figure-callout\; id="0"\; label="AT"\; filenames="imgf0003.png"\; state="\{\{state\}\}">AT</figure-callout>}}_0.\mathrm{<figure-callout\; id="0"\; label="cos\; \omega "\; filenames="imgf0003.png"\; state="\{\{state\}\}">cos\; </figure-callout>}\left({\mathrm{\omega }}_{}\right)\left({\mathrm{}}_0.\mathrm{x}+{\mathrm{<figure-callout\; id="0"\; label="\phi "\; filenames="imgf0003.png"\; state="\{\{state\}\}">\phi </figure-callout>}}_0\right)+{\mathrm{<figure-callout\; id="1"\; label="AT"\; filenames="imgf0001.png"\; state="\{\{state\}\}">AT</figure-callout>}}_1.\mathrm{<figure-callout\; id="1"\; label="cos\; \omega "\; filenames="imgf0001.png"\; state="\{\{state\}\}">cos\; </figure-callout>}\left({\mathrm{\omega }}_{}\right)\left({\mathrm{}}_1.\mathrm{x}+{\mathrm{<figure-callout\; id="1"\; label="\phi "\; filenames="imgf0001.png"\; state="\{\{state\}\}">\phi </figure-callout>}}_1\right)+{\mathrm{<figure-callout\; id="2"\; label="AT"\; filenames="imgf0002.png"\; state="\{\{state\}\}">AT</figure-callout>}}_2.\mathrm{<figure-callout\; id="2"\; label="cos\; \omega "\; filenames="imgf0002.png"\; state="\{\{state\}\}">cos\; </figure-callout>}\left({\mathrm{\omega }}_{}\right)\left({\mathrm{}}_2.\mathrm{x}+{\mathrm{<figure-callout\; id="2"\; label="\phi "\; filenames="imgf0002.png"\; state="\{\{state\}\}">\phi </figure-callout>}}_2\right)+...+{\mathrm{AT}}_{\mathrm{not}}.\cos \left({\mathrm{\omega }}_{\mathrm{not}}.\mathrm{x}+{\mathrm{\phi }}_{\mathrm{not}}\right)$$

• where φ ₀ , ..., φ _n is the phase,
• ω ₀ , ..., ω _n is the spatial pulsation,
• v (x) is the signal of arrows resulting from the measurement of a track profile by a measuring device characterized by an FT Transfer Function ₁ .

The signal V (x) corresponding to the signal of arrows extrapolated on a different basis is expressed $$\begin{array}{l}\mathrm{V}\left(\mathrm{x}\right)={\mathrm{AT}}_0\text{'}.\mathrm{<figure-callout\; id="0"\; label="cos\; \omega "\; filenames="imgf0003.png"\; state="\{\{state\}\}">cos\; </figure-callout>}\left({\mathrm{\omega }}_{}\right)\left({\mathrm{}}_0.\mathrm{x}+{\mathrm{\phi }}_0\text{'}\right)+{\mathrm{AT}}_1\text{'}.\mathrm{<figure-callout\; id="1"\; label="cos\; \omega "\; filenames="imgf0001.png"\; state="\{\{state\}\}">cos\; </figure-callout>}\left({\mathrm{\omega }}_{}\right)\left({\mathrm{}}_1.\mathrm{x}+{\mathrm{\phi }}_1\text{'}\right)+{\mathrm{AT}}_2\text{'}.\cos \left({\mathrm{\omega }}_2+{\mathrm{\phi }}_2\text{'}\right)+...+{\mathrm{AT}}_{\mathrm{not}}\text{'}.\cos (\\ {\mathrm{\omega }}_{\mathrm{not}}.\mathrm{x}+{\mathrm{\phi }}_{\mathrm{not}}\text{'})\end{array}$$

Where the amplitudes are modified as follows: $$\begin{array}{l}{\mathrm{AT}}_0\text{'}={\mathrm{AT}}_0\cdot \frac{{\left|\mathrm{<figure-callout\; id="2"\; label="F\; T"\; filenames="imgf0002.png"\; state="\{\{state\}\}">F\; </figure-callout>}{T}_{}{}_2\right|}_{\left({\mathrm{<figure-callout\; id="0"\; label="\omega "\; filenames="imgf0003.png"\; state="\{\{state\}\}">\omega </figure-callout>}}_0\right)}}{{\left|\mathrm{<figure-callout\; id="1"\; label="F\; T"\; filenames="imgf0001.png"\; state="\{\{state\}\}">F\; </figure-callout>}{T}_{}{}_1\right|}_{\left({\mathrm{<figure-callout\; id="0"\; label="\omega "\; filenames="imgf0003.png"\; state="\{\{state\}\}">\omega </figure-callout>}}_0\right)}}\mathrm{}{\mathrm{AT}}_1^{\text{'}}={\mathrm{AT}}_1\cdot \frac{{\left|\mathrm{<figure-callout\; id="2"\; label="F\; T"\; filenames="imgf0002.png"\; state="\{\{state\}\}">F\; </figure-callout>}{T}_{}{}_2\right|}_{\left({\mathrm{<figure-callout\; id="1"\; label="\omega "\; filenames="imgf0001.png"\; state="\{\{state\}\}">\omega </figure-callout>}}_1\right)}}{{\left|\mathrm{<figure-callout\; id="1"\; label="F\; T"\; filenames="imgf0001.png"\; state="\{\{state\}\}">F\; </figure-callout>}{T}_{}{}_1\right|}_{\left({\mathrm{<figure-callout\; id="1"\; label="\omega "\; filenames="imgf0001.png"\; state="\{\{state\}\}">\omega </figure-callout>}}_1\right)}}\mathrm{}{\mathrm{AT}}_2\text{'}={\mathrm{AT}}_2\cdot \frac{{\left|\mathrm{<figure-callout\; id="2"\; label="F\; T"\; filenames="imgf0002.png"\; state="\{\{state\}\}">F\; </figure-callout>}{T}_{}{}_2\right|}_{\left({\mathrm{<figure-callout\; id="2"\; label="\omega "\; filenames="imgf0002.png"\; state="\{\{state\}\}">\omega </figure-callout>}}_2\right)}}{{\left|\mathrm{<figure-callout\; id="1"\; label="F\; T"\; filenames="imgf0001.png"\; state="\{\{state\}\}">F\; </figure-callout>}{T}_{}{}_1\right|}_{\left({\mathrm{<figure-callout\; id="2"\; label="\omega "\; filenames="imgf0002.png"\; state="\{\{state\}\}">\omega </figure-callout>}}_2\right)}}\\ ...\mathrm{}{\mathrm{AT}}_{\mathrm{not}}\text{'}={\mathrm{AT}}_{\mathrm{not}}\cdot \frac{{\left|\mathrm{<figure-callout\; id="2"\; label="F\; T"\; filenames="imgf0002.png"\; state="\{\{state\}\}">F\; </figure-callout>}{T}_{}{}_2\right|}_{\left({\omega }_{\mathrm{not}}\right)}}{{\left|\mathrm{<figure-callout\; id="1"\; label="F\; T"\; filenames="imgf0001.png"\; state="\{\{state\}\}">F\; </figure-callout>}{T}_{}{}_1\right|}_{\left({\omega }_{\mathrm{not}}\right)}}\end{array}$$

And the phases are modified in this way: $$\begin{array}{ll}{\phi }_0^{\text{'}}& ={\mathrm{<figure-callout\; id="0"\; label="\phi "\; filenames="imgf0003.png"\; state="\{\{state\}\}">\phi </figure-callout>}}_0+\mathrm{<figure-callout\; id="2"\; label="arg\; FT"\; filenames="imgf0002.png"\; state="\{\{state\}\}">arg\; </figure-callout>}{\left({\mathrm{FT}}_{}\right)}_{}{\left({}_2\right)}_{\left({\mathrm{\omega }}_0\right)}-\mathrm{<figure-callout\; id="1"\; label="arg\; FT"\; filenames="imgf0001.png"\; state="\{\{state\}\}">arg\; </figure-callout>}{\left({\mathrm{FT}}_{}\right)}_{}{\left({}_1\right)}_{\left({\mathrm{<figure-callout\; id="0"\; label="\omega "\; filenames="imgf0003.png"\; state="\{\{state\}\}">\omega </figure-callout>}}_0\right)}\\ {\phi }_1^{\text{'}}& ={\mathrm{<figure-callout\; id="1"\; label="\phi "\; filenames="imgf0001.png"\; state="\{\{state\}\}">\phi </figure-callout>}}_1+\mathrm{<figure-callout\; id="2"\; label="arg\; FT"\; filenames="imgf0002.png"\; state="\{\{state\}\}">arg\; </figure-callout>}{\left({\mathrm{FT}}_{}\right)}_{}{\left({}_2\right)}_{\left({\mathrm{\omega }}_1\right)}-\mathrm{<figure-callout\; id="1"\; label="arg\; FT"\; filenames="imgf0001.png"\; state="\{\{state\}\}">arg\; </figure-callout>}{\left({\mathrm{FT}}_{}\right)}_{}{\left({}_1\right)}_{\left({\mathrm{<figure-callout\; id="1"\; label="\omega "\; filenames="imgf0001.png"\; state="\{\{state\}\}">\omega </figure-callout>}}_1\right)}\\ {\phi }_2^{\text{'}}& ={\mathrm{<figure-callout\; id="2"\; label="\phi "\; filenames="imgf0002.png"\; state="\{\{state\}\}">\phi </figure-callout>}}_2+\mathrm{<figure-callout\; id="2"\; label="arg\; FT"\; filenames="imgf0002.png"\; state="\{\{state\}\}">arg\; </figure-callout>}{\left({\mathrm{FT}}_{}\right)}_{}{\left({}_2\right)}_{\left({\mathrm{\omega }}_2\right)}-\mathrm{<figure-callout\; id="1"\; label="arg\; FT"\; filenames="imgf0001.png"\; state="\{\{state\}\}">arg\; </figure-callout>}{\left({\mathrm{FT}}_{}\right)}_{}{\left({}_1\right)}_{\left({\mathrm{<figure-callout\; id="2"\; label="\omega "\; filenames="imgf0002.png"\; state="\{\{state\}\}">\omega </figure-callout>}}_2\right)}\\ \cdots & \\ {\phi }_{\mathrm{not}}^{\text{'}}& ={\phi }_{\mathrm{not}}+\mathrm{<figure-callout\; id="2"\; label="arg\; FT"\; filenames="imgf0002.png"\; state="\{\{state\}\}">arg\; </figure-callout>}{\left({\mathrm{FT}}_{}\right)}_{}{\left({}_2\right)}_{\left({\mathrm{\omega }}_{\mathrm{not}}\right)}-\mathrm{<figure-callout\; id="1"\; label="arg\; FT"\; filenames="imgf0001.png"\; state="\{\{state\}\}">arg\; </figure-callout>}{\left({\mathrm{FT}}_{}\right)}_{}{\left({}_1\right)}_{\left({\mathrm{\omega }}_{\mathrm{not}}\right)}\end{array}$$

This signal obtained from an extrapolation is called "signal of arrows equivalent on a long base". Thus, the "equivalent base arrows 31m" correspond to a transition from the short base to the long base by the multiplication method of the amplitude of each component of the short base signal by a ratio for each component.

qui correspond bien à la description absolue de la géométrie en plan horizontal et en plan vertical de la voie ferrée.We can find in the same way, the absolute amplitudes of the components of the signal E (x) describing the absolute profile of leveling and training of the way by taking a function of transfer of the long base system equal to 1. One thus finds: $$\mathrm{E}\left(\mathrm{x}\right)={\mathrm{<figure-callout\; id="0"\; label="E"\; filenames="imgf0003.png"\; state="\{\{state\}\}">E</figure-callout>}}_0.\mathrm{<figure-callout\; id="0"\; label="cos\; \omega "\; filenames="imgf0003.png"\; state="\{\{state\}\}">cos\; </figure-callout>}\left({\mathrm{\omega }}_{}\right)\left({\mathrm{}}_0.\mathrm{x}+{\mathrm{<figure-callout\; id="0"\; label="\phi "\; filenames="imgf0003.png"\; state="\{\{state\}\}">\phi </figure-callout>}}_0\right)+{\mathrm{<figure-callout\; id="1"\; label="E"\; filenames="imgf0001.png"\; state="\{\{state\}\}">E</figure-callout>}}_1.\mathrm{<figure-callout\; id="1"\; label="cos\; \omega "\; filenames="imgf0001.png"\; state="\{\{state\}\}">cos\; </figure-callout>}\left({\mathrm{\omega }}_{}\right)\left({\mathrm{}}_1.\mathrm{x}+{\mathrm{<figure-callout\; id="1"\; label="\phi "\; filenames="imgf0001.png"\; state="\{\{state\}\}">\phi </figure-callout>}}_1\right)+{\mathrm{<figure-callout\; id="2"\; label="E"\; filenames="imgf0002.png"\; state="\{\{state\}\}">E</figure-callout>}}_2.\mathrm{<figure-callout\; id="2"\; label="cos\; \omega "\; filenames="imgf0002.png"\; state="\{\{state\}\}">cos\; </figure-callout>}\left({\mathrm{\omega }}_{}\right)\left({\mathrm{}}_2.\mathrm{x}+{\mathrm{<figure-callout\; id="2"\; label="\phi "\; filenames="imgf0002.png"\; state="\{\{state\}\}">\phi </figure-callout>}}_2\right)+...+{\mathrm{E}}_{\mathrm{not}}.\cos \left({\mathrm{\omega }}_{\mathrm{not}}.\mathrm{x}+{\mathrm{\phi }}_{\mathrm{not}}\right)$$

which corresponds to the absolute description of the geometry in horizontal plane and in vertical plane of the railway.

These are particular methods of applying these general principles which are described.

Advantageously, the impulse response filter is an infinite impulse response filter.

• une sous-étape 60 d'obtention des valeurs numériques des modules et arguments d'une fonction de transfert caractérisant le dispositif de mesure,
• une sous-étape 61 d'inversion numérique des modules et de prise de l'opposé des arguments de ladite fonction de transfert,
• une sous-étape 63 d'une estimation polynomiale de la fonction de transfert inverse à partir des modules et arguments de la fonction de transfert inverse,

lesdits coefficients de la fonction polynomiale du filtre à réponse impulsionnelle correspondant aux coefficients de l'estimation polynomiale de la fonction de transfert inverse.The estimation method comprises a preliminary step of determining the coefficients of the polynomial function of the impulse response filter comprising:

• a substep 60 of obtaining the numerical values of the modules and arguments of a transfer function characterizing the measuring device,
• a substep 61 of digital inversion of the modules and taking the opposite of the arguments of said transfer function,
• a sub-step 63 of a polynomial estimation of the inverse transfer function from the modules and arguments of the inverse transfer function,

said coefficients of the polynomial function of the impulse response filter corresponding to the coefficients of the polynomial estimation of the inverse transfer function.

The preliminary step can be carried out for each measurement of the geometrical parameters of a railway line. But advantageously, the coefficients of the polynomial estimation of the inverse transfer function being always the same for the measuring device, this step can be carried out once and only for a measuring device.

This step is to be performed for each different measuring device used.

Advantageously, the numerical values of the modules and arguments of the transfer function characterizing the measuring device are obtained from a kinematic modeling. The use of modeling kinematic measurement device allows to take into account that said measuring device, by the arrangement of its various components is not rigorously a three-point system. The kinematic modeling algorithm provides a rigorous representation of the actual and non-approximate transfer function of the measuring device. This modeling uses the properties of linearity, continuity and invariability of chord measurement devices as commonly accepted by those skilled in the art, in order to use the superposition theorems. The behavior of the measuring device is studied in order to know its theoretical response to a unitary input (example: sinusoidal input of precise wavelength, niche input, ramp input ...). The total response of the measuring device corresponds to the sum of the unit responses. We have seen that the geometry of the railway can be described for the leveling and the dressing by a series of Fourier, like sum of sinusoidal components describing a pink noise and lines specific to very particular wavelengths. The transfer function of the measuring device will therefore be easily determined by the study of each elementary response to these unitary inputs. The kinematic modeling, by numerical calculation, of a measuring device rolling on a railway makes it possible to determine the modification of the amplitude and the phase of the elementary signals by the filter constituted by said measuring device. Since the transfer function is a mathematical function of the wavelength of the frequency components describing the dressage (or leveling) and the asymmetry of the measurement on the string materializing the relative measurement base, the algorithm works by iteration with a sufficiently narrow pitch.

The modules of the transfer function are therefore known for each frequency component of wavelengths (λ) varying from λmin to λmax according to an increment corresponding to the iteration step referred to in the preceding paragraph. Their determination is made by the ratio of the amplitude of the frequency component corresponding to the output of the measuring device to the amplitude of the frequency component corresponding to the digitally simulated input. The arguments are determined by the difference of the phases at the origin of these same signals.

In a preferred embodiment, the preliminary step of determining the coefficients of the polynomial function of the impulse response filter comprises a sub-step 62 of frequency windowing of the inverse transfer function, in which the substep of polynomial estimation of the inverse transfer function from the modules and arguments of the inverse transfer function is performed for each window and wherein the arrow signal is windowed frequently 65 before application of the impulse response filter.

In an exemplary embodiment, the determination of the high and low limits of the windows is performed according to the curve of the module of the inverse transfer function. The high and low limits are defined from the slopes of the module of the inverse transfer function, by calculating the variation of the second derivative of the module. When this variation is greater than a predefined threshold, a high / low limit is determined.

• une sous étape d'obtention des valeurs numériques des modules et arguments d'une fonction de transfert caractérisant un deuxième dispositif de mesure de base de mesure plus grande, s'ajoute à la sous étape d'obtention des valeurs numériques des modules et arguments d'une fonction de transfert caractérisant le dispositif de mesure,
• une sous étape de multiplication par le module de la fonction de transfert du deuxième dispositif et de sommation de l'argument de la fonction de transfert du deuxième dispositif s'ajoute à la sous-étape d'inversion numérique des modules et prise de l'opposé des arguments de ladite fonction de transfert,
• la sous- étape d'estimation polynomiale de la fonction de transfert inverse à partir des modules et arguments de la fonction de transfert inverse est remplacée par une sous- étape d'estimation polynomiale du rapport des fonctions de transfert caractérisant le deuxième dispositif et le dispositif à partir des rapports des modules et de la différence des arguments des fonctions de transfert.

When it is desired to obtain a signal of arrows on a basis of measurement that is virtually elongated from arrow signals obtained by the measuring device, the preliminary step of determining the coefficients of the polynomial function of the impulse response filter is modified. in such a way that :

• a sub-step of obtaining the numerical values of the modules and arguments of a transfer function characterizing a second measurement device of greater measurement base, is added to the sub-step of obtaining the numerical values of the modules and arguments of a transfer function characterizing the measuring device,
• a sub-step of multiplication by the module of the transfer function of the second device and summation of the argument of the transfer function of the second device is added to the digital inversion sub-step of the modules and taken from the opposite arguments of said transfer function,
• the sub-step of polynomial estimation of the inverse transfer function from the modules and arguments of the inverse transfer function is replaced by a substep of estimation polynomial report of the transfer functions characterizing the second device and the device from the reports of the modules and the difference of the arguments of the transfer functions.

• le calcul du signal de flèches sur base allongée (extrapolation du signal des flèches) à partir du signal de flèches sur base courte, que ce soit pour les flèches verticales ou horizontales,
• le calcul du signal sur une même base de mesure mais dans une configuration de prise de mesure différente.

The signal processing method therefore makes it possible, for the measuring device:

• the calculation of the arrows signal on an elongated base (extrapolation of the signal of the arrows) from the signal of arrows on a short base, whether for the vertical or horizontal arrows,
• the calculation of the signal on the same measurement basis but in a different measurement configuration.

The geometric characteristics of the measuring device can advantageously be calculated so as to facilitate the method for estimating an absolute profile and the method for obtaining an arrows signal on an elongated measuring basis.

These geometrical characteristics of the measuring device are advantageously determined by an optimization loop on the kinematic modeling algorithm of the estimation method of an absolute profile and the method of obtaining an arrows signal on the basis of elongated measurement. .

Thus, in an exemplary optimization of the measuring carriage of the invention, each measuring arm has a length of 5.2 m. Both measuring arms have a total length of 10.4m. This total length is a compromise between the minimum length of the measurement base of a measurement system in order to obtain a transfer function whose cut-off of long wavelength components is compatible with the expected results under the terms of the application of the signal processing method aimed at obtaining frequency components whose wavelengths vary between 3m and 70m or the domains D1 and D2 and the need for a structure which will not influence the measurement and whose the bending and torsion values must remain small in front of the resolution of the track geometry measurements made.

The length of the arms is an element of the optimization of the device of measurement to allow the easy implementation of the method of processing the measurement signals. The modeling of such a measuring device as presented uses a description by transfer function linking the input (the real, absolute profile of the channel) to the output signal (the image that is given). This transfer function has a module which is a function of the wavelength of the measured faults (parameter of the input) but also of the characteristics of the measuring system, in particular the lengths of the measuring arms.

Preferably, in order to implement the signal processing method associated with the measuring device, the total length of the two measuring arms, but also their individual length, must be accurately dimensioned.

The total length of the measurement arm must be such that it remains lower than 1/7 ^th of the value of the wavelength of the leveling defects or longer training which is desired to restore the absolute magnitude, but also that this length defines a system with a transfer function such that the ratio of the modules between the transfer function of the elongated base system that is desired and said transfer function is less than or equal to 4 for the objective elongated base .

Indeed, concerning the obtaining of arrows on an extrapolated basis, it is desired that the ratio of the modules (module of the virtually elongated basic transfer function and modulus of the transfer function of the measurement system) used in the described method remains lower than at a value of 4.

The limit lies essentially in the value of the reports of the modules. We can not hope to find the amplitude of the components that have been attenuated by more than 80 - 90%.

Thus, one can not hope to obtain an extrapolation on bases whose length to obtain necessarily leads to have reports of FT where at the denominator one finds attenuations too great (which corresponds to the attenuations of the system with the shortest rope at beyond certain wavelength values). This would result in excessive values of the ratio of modules for certain wavelengths. Now, since the amplitude of the signal components is multiplied by this ratio according to the wavelengths, we would be led to see certain amplitudes of components multiplied by very high values. The noise would be amplified as well.

Thus, a transfer function corresponding to a measuring device with a large measurement base, will have a fairly wide bandwidth and therefore repel large attenuations at very large wavelengths. In comparison, the transfer function of the measuring device that one wishes to "extrapolate" leads to fairly fast attenuation at long wavelengths. It is therefore necessary to select from the appearance of the transfer function of the shortest measuring device, the wavelengths beyond which we can hardly go because the attenuation becomes too strong. This is to avoid problems with outlier values.

This explains the problem of choosing a length of a measuring system whose length must be at least.

It is essentially the values of the ratio of the transfer functions that one seeks to control through the choice of attenuation values of the filter corresponding to the system to be extrapolated. Indeed, too large attenuation values at the denominator will lead to a ratio that is too great. This ratio (for a specific wavelength) being multiplied by the amplitude of the component (having this wavelength), there is a risk of amplifying the noise as well as the signal.

To express the limit for the extrapolation, we must take into account two aspects: we can extrapolate from one base to another as long as the ratio of the modules is not greater than four for a few wavelengths whatsoever . This limit of four is based only on the level of accuracy of the extrapolated arrow signal that is desired and the level of accuracy found in the measurement using the measurement system described. This choice depends on the fact that the precision that a person skilled in the art accepts for an extrapolated arrow measurement is of the order of a millimeter. The best achievable accuracy for geometry measurement systems should not be less than 0.25mm. The ratio of 4 is therefore related to this report of the details.

Those skilled in the art, a specialist in layout study questions, frequently use curve correction methods by the method of arrows. These curve rectification methods are therefore based on input data provided by measuring devices providing arrows on bases 20 m long.

• « Nouvelle méthode de raccordement des courbes » par M. E. HALLADE, RGCF 31ème année - 1er semestre avril 1908 - n° 4 ,
• V-693 « Dévers à donner aux voies principales - Raccordements des courbes entre elles et avec les alignements droits - Rectification des courbes déformées » Chemins de fer de Paris à Lyon et à la Méditerranée Service de la Voie 1928 ,
• « COURBES des CHEMINS DE FER » conférence par M. CHAPPELET année 1930 - 1931 ,
• « Le raccordement parfait » par M. A. CAQUOT, RGCF - 68ème année janvier 49 - n°1 ,
• « RECTIFICATION DU TRACE DES COURBES » mémento didactique école Nationale de Nanterre M. PLOUDRE 1983 ,
• « Les raccordements de courbure et de dévers dans le tracé des voies de chemin de fer, étude globale du problème » par M. H. PERROT 1983 ,

Many publications exist:

• "New method of connecting curves" by ME HALLADE, RGCF 31st year - 1st semester April 1908 - n ° 4 ,
• V-693 «Overflow to give to the main tracks - Connections between the curves and with straight alignments - Rectification of deformed curves» Railways from Paris to Lyon and the Mediterranean Service of the Way 1928 ,
• "CURVES OF RAILWAYS" conference by M. CHAPPELET year 1930 - 1931 ,
• "The perfect connection" by MA CAQUOT, RGCF - 68th year January 49 - n ° 1 ,
• "RECTIFICATION OF THE TRACE OF CURVES" memento didactic National School of Nanterre M. PLOUDRE 1983 ,
• "Curvature and cant connections in railway tracks, an overall study of the problem" by MH PERROT 1983 ,

Have frozen the state of the art regarding measurement requirements for line rectification studies.

The measurement bases of the arrows are all described as 20m. Currently, these methods are still in effect on large national networks and the need for input data involves a supply of 20m-based arrows.

Such basic measurement lengths for physical systems, of the "lorries" type, can not be envisaged with the degree of precision of the arrows to be measured, a millimeter desired by those skilled in the art. Indeed, simple modeling of the resistance of the materials, show that the deformations of the structures necessarily composing these measuring lorries, if they were about twenty meters long are much greater than the millimeter, in particular in the curves of strong cant.

The measuring device as described, has been dimensioned to obtain, using the method described, arrows on the basis of virtually elongated by 20m, using a shorter actual measurement measuring device, the length of which makes it possible to envisage smaller deformations.

Preferably, a total length of 10.4m is used, equal to 1 / 6.7 ^e of the value of the upper bound of the domain D 2 which is 70 m. This total length therefore makes it possible to respect a ratio of the modules of less than 4 to obtain extrapolated arrows on a virtual base of 20m in length.

The length of the measuring arm should preferably be different in order to obtain an asymmetric positioning of the guide carriage which carries the measuring head and which materializes the point of the rope where the vertical or horizontal arrow is measured so that the module of the Transfer function does not have zero for components of the particular wavelength signal, such as for example the half string or the quarter chord for symmetrical chord measurement systems.

Claims (3)

1. Method for estimating an absolute profile of a railway track comprising the steps:

   - of obtaining alignment versine signals via a measurement device (1),

   - of applying (50) an impulse response filter (51) to the alignment versine signals, the said impulse response filter being characterized by a polynomial function whose coefficients are determined on the basis of an inverse transfer function of the said measurement device,

   characterized in that the method comprises a prior step of determining the coefficients of the polynomial function of the impulse response filter, the said step comprising:

   - a sub-step (60) of obtaining the numerical values of the moduli and arguments of a transfer function characterizing the measurement device,

   - a sub-step (61) of numerically inverting the moduli and of taking the opposite of the arguments of the said transfer function,

   - a sub-step (63) of a polynomial estimation of the inverse transfer function on the basis of the moduli and arguments of the inverse transfer function,

   the said coefficients of the polynomial function of the impulse response filter corresponding to the coefficients of the polynomial estimation of the inverse transfer function.
2. Method of estimation according to Claim 1, wherein the numerical values of the moduli and arguments of the transfer function characterizing the measurement device are obtained on the basis of a kinematic modelling.
3. Method of estimation according to one of the preceding claims, wherein the prior step of determining the coefficients of the polynomial function of the impulse response filter comprises a sub-step of frequency windowing (62) of the inverse transfer function, wherein the sub-step of polynomial estimation of the inverse transfer function on the basis of the moduli and arguments of the inverse transfer function is carried out for each window and wherein the alignment versine signal is windowed frequency-wise before applying the impulse response filter.

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