Method and system for checking a securing of at least one rail of a track

Abstract

The invention relates to a method for checking a securing of at least one rail (4a, 4b) of a track (3), comprising the following steps: generating a mechanical movement (Fv); pressing at least one first transmission element (16a, 16b) onto the rail (4a, 4b) using at least one first pressing element (14), wherein the first pressing element (14) generates a first contact pressure (PI) according to a first static target pressure (Plstatisch_ soll); transmitting the mechanical movement (Fv) to the rail (4a, 4b); detecting the movement reactions (R) of the rail (4a, 4b) due to the mechanical movement (Fv) at a first (27) and a second point (28); comparing the movement reaction (R) of the rail (4a, 4b) at the first point (27) with the movement reaction (R) of the rail (4a, 4b) at the second point (28); and evaluating the rail securing on the basis of the comparison of the movement reactions (R) of the rail (4a, 4b) at the first and the second point (28). The invention also relates to a system (7) for carrying out the method.

Description

[0001] Method and system for checking the fastening of at least one rail of a track

[0002] Technical area

[0003]

[0001] The invention relates to a method and a system for checking a fastening of at least one rail of a track.

[0004] State of the art

[0005]

[0002] Defective rail fastenings pose a high safety risk to people and rail vehicles. Therefore, tracks, especially after construction or maintenance work, must be inspected very carefully for possible defects in the rail fastening. A visual inspection is very time-consuming and, in most cases, inadequate.

[0006]

[0003] Since the subsurface of the rails must also be sufficiently solid, the fastening of the rails is defined not only by the direct fixing of the rails to the sleepers, but also by the tamping of the underlying track bed. Proper tamping of the sleepers is a prerequisite for the long-term preservation of the track geometry and thus for lower infrastructure costs and high safety on the railway line. However, it is hardly possible, or very difficult, to check the tamping of the track bed beneath the sleeper using known methods. Poor tamping usually only becomes apparent when the track geometry changes after it has been subjected to operational loads.

[0007]

[0004] AT 523 949 A1 discloses a machine for compacting a ballast bed of a track, which can be used to detect weak points in the track during the stabilization process. The machine has spreading and clamping drives for applying a variable horizontal load to the rails, as well as a measuring device for detecting rail head deflections or track gauge changes caused by the variable horizontal load. Based on the rail head deflections or track gauge changes, it is possible to determine whether the track structure is inherently stable.

[0008]

[0005] A disadvantage of the device known from AT 523 949 A1 is that an additional load force of a lower frequency must be superimposed on the inherently higher-frequency vibration movement of the spreading and clamping drives, and deliberately induced low-frequency track gauge changes caused by the additional load force must be accepted, which in turn can impair the quality of the rail fastening. Furthermore, the tamping of the track bed cannot be verified by measuring the reaction to the additional load force, since no force resulting from the additional, horizontally acting load force reacts and can be measured from the area below the track sleepers.

[0009] Description of the invention

[0010]

[0006] In light of these statements, the object of the present invention is to alleviate or even completely eliminate the disadvantages of the prior art. Preferably, the object of the present invention is to provide a method and a system with which the fastening of a rail of a track, which particularly preferably also concerns the tamping of the track, can be checked in a simple manner and with little additional effort.

[0011]

[0007] This object is achieved by a method according to claim 1 and by a system according to claim 11. Preferred embodiments are specified in the dependent claims.

[0012]

[0008] The method according to the invention for checking the fastening of at least one rail of a track comprises the following steps: generating a mechanical movement, in particular a vibration movement, by means of a movement unit arranged on a device movable along the track; pressing at least one first transmission element of the movable device, in particular a first roller, against the rail by means of at least one first pressing element, wherein the first pressing element generates a first contact pressure according to a first static target pressure;

[0013] Transferring the mechanical movement to the rail;

[0014] detecting the movement reactions of the rail as a result of the mechanical movement at a first location and at a second location, the locations being spaced apart from one another in the longitudinal direction of the rail;

[0015] Comparing the movement response, in particular amplitude and phase position, of the rail at the first location with the movement response, in particular amplitude and phase position, of the rail at the second location; and

[0016] Evaluate the rail fastening based on comparing the motion response of the rail at the first location with the motion response of the rail at the second location.

[0017]

[0009] The invention is based on the finding that a potentially inadequate rail fastening can be identified by comparing the movement responses of a rail at different locations. If the rail fastening is inadequate at one of the locations, the rail is more mobile at that location than at one of the other locations where the rail is properly fastened, so that the movement responses of the rail at the locations differ as a result of the transmitted mechanical movement, particularly in amplitude and phase. It was found that the method according to the invention can also detect the under-tamping of the track, which constitutes part of the rail fastening, since this affects the movement response of the rail due to the more flexible subsurface.This is because the mechanical movement is also transmitted into the tamping and causes corresponding reaction forces there, which is not the case with a horizontal loading force as in AT 523 949 A1.

[0010] Advantageously, the method according to the invention can be combined with track stabilization by a dynamic track stabilizer (DGS), since during track stabilization a mechanical movement is already transmitted to the rails of the track in order to stabilize the track or the track bed. It is therefore advantageous if the movable device according to the invention is designed as a dynamic track stabilizer in one embodiment of the invention. A DGS has a movement unit for generating a mechanical movement, in particular a vibratory movement, and is used to compact the grains in the track bed after a tamping process.The mechanical movement of the DGS can be used to generate movement reactions of the rails at different locations, which can be compared with each other using the method according to the invention.

[0018]

[0011] The mechanical movement is preferably a periodic vibration movement. However, the mechanical movement can generally have any form and be limited in time. The mechanical movement can be generated, for example, by means of one or more rotating unbalanced masses. The movement unit can be mounted on a frame of the movable device, so that the mechanical movement is transmitted to the rail via the frame, the at least one first pressure element, and the at least one first transmission element.

[0019]

[0012] The movable device can be designed to be independently movable along the rail by means of its own drive and / or, in particular, to be displaceable by a preferably superordinate rail vehicle. For this purpose, the movable device can have wheels or rollers that can roll along a track. If the mechanical movement is a vibration movement, its frequency is preferably between 25 Hz and 40 Hz, in particular between 30 Hz and 35 Hz.

[0020]

[0013] In one embodiment of the invention, the mechanical movement has an amplitude selected such that a correctly fastened rail head experiences a horizontal movement with an amplitude of between 1 mm and 2 mm when viewed from above. Such an amplitude does not impair the rail fastening but allows for the detection of errors or deficiencies in the rail fastening.

[0021]

[0014] To transmit the mechanical movement to a rail of a track, the movable device has at least one first transmission element, which is preferably designed as a first roller for the purpose of mobility. The first transmission element is pressed against the rail by means of the first pressing element, whereby the applied first contact pressure corresponds to a first static target pressure. Preferably, the first transmission element is pressed from the center of the track outward against the inside of the rail, as seen in a plan view of the track.

[0022]

[0015] In order to transmit the mechanical movement to the other rail of the same track, a further first transmission element, which can also be designed as a first roller, can preferably be provided at the same longitudinal position of the track opposite the first transmission element. The further first transmission element can be pressed against the other rail of the track using the same first pressing element or using a further first pressing element, so that the device is clamped between the rails of the track.

[0023]

[0016] In the case of a further first contact pressure element, this generates a further first contact pressure according to a further first static target pressure, which is preferably substantially identical to the first static target pressure. Mirrored to the first transmission element, the further first transmission element is preferably pressed from the center of the track outwards against the inside of the further rail in a plan view of the track. The first transmission elements can therefore be pressed in opposite directions against the rails of a track. In this case, the movable device is spread between the rails, which is why the at least one first contact pressure element can also be referred to as a spreading drive.

[0017] In a preferred embodiment of the invention, at least one second transmission element, in particular a second roller, can also be provided, which is offset in the direction of travel of the device.The second transmission element can be pressed against the inside of the rail by means of a second pressure element which generates a second contact pressure according to a second desired pressure in order to transmit the mechanical movement to the rail.

[0024]

[0018] As with the first transmission element, a further second transmission element, which can also be designed as a second roller, can also be provided, preferably at the same longitudinal position of the track opposite the second transmission element. The further second transmission element can be pressed against the further rail of the track using the same second pressing element or using a further second pressing element. In the case of a further second pressing element, this generates a further second contact pressure according to a further second static target pressure, which is preferably substantially identical to the second static target pressure. As already described in connection with the first and further first transmission element, the second or further second transmission element can be pressed against the inside of the rail or the further rail.By means of the (further) first and (further) second pressing and transmission element, the mechanical movement can be transmitted to two different longitudinal positions of the rail or the further rail of the same track.

[0025]

[0019] All pressing elements and transmission elements can be designed similarly. Statements in the present disclosure that refer to the first pressing element and the first transmission element also apply, unless otherwise stated, to all other pressing elements and all other transmission elements.

[0026]

[0020] In order to fix the device even better to the track, one or more clamping rollers can also be provided, which can be placed on an outer side of the rail and / or the further rail and which press the rail and / or the further rail towards the center of the track when viewed from the outer side in a plan view of the track. For example, a clamping roller can be assigned to each first, further first, second and / or further second transmission element. It can also be provided that, viewed in the direction of travel of the device, a clamping roller is provided between the first and the second transmission element and / or between the further first and the further second transmission element.

[0027]

[0021] The first pressing element and the first transmission element are described in more detail below. However, the explanations are transferable to the other pressing elements and transmission elements, in particular if they are designed similarly to the first pressing element or the first transmission element. The first pressing element can be formed by a hydraulic and / or pneumatic cylinder. The first static target pressure can be regulated and / or controlled. A dynamic pressure can be superimposed on the first static target pressure during operation. The dynamic pressure generated by the first pressing element can be in the range between 10 bar and 120 bar, in particular between 20 bar and 110 bar. A time-average value of the pressure, which can correspond to the first static target pressure, can be between 40 bar and 80 bar, for example 60 bar.This can result in dynamic compressive forces between 1.1 kN and 7 kN, particularly between 1.2 kN and 6.6 kN, acting on the transmission element. A time-averaged compressive force can be between 3 kN and 4 kN, for example, 3.6 kN.

[0028]

[0022] Alternatively, the first pressure element can also be formed, for example, by a fixable rod. Due to the mechanical movement transmitted to a rail by the first transmission element, the rail is also set in motion. The movement response is a measure of the rail's fastening quality. The movement response of the rail can be detected directly or indirectly. For example, the movement response can be measured using an optical, inductive, capacitive, and / or electromechanical sensor. The movement response of the rail can be detected as a discrete or continuous temporal progression.

[0029]

[0023] According to the invention, the movement reactions of the rail are recorded at a first and a second location on the rail, different from the first. For this purpose, in one embodiment, the movable device can be moved to the first and second locations. The first and second locations on the rail can be spaced apart from each other, for example, by at least 60 cm, preferably at least 100 cm, and particularly preferably at least 140 cm. The greater the distance, the better the movement reactions at the locations are decoupled from each other.

[0030]

[0024] After recording the movement reactions at the first and second locations, the movement reactions are compared. Preferably, only the dynamic components of the movement reactions are used for the comparison. If the difference between the movement reactions, particularly in amplitude and / or phase, is greater than a predetermined limit, it can be assumed that there is a defective or inadequate rail fastening at one of the two locations.

[0031]

[0025] The comparison of the movement reactions can be based on a mathematical operation. For this purpose, for example, a class of mathematical operations can be selected that multiplicatively links the movement reactions, preferably in combination with temporal integration. Concrete examples of this are auto- or cross-correlation functions or convolution. However, the method also works if, for example, the amplitudes and / or phases of the movement reactions are directly compared. A defective rail fastening may be present, for example, if an amplitude and / or phase difference between the movement reactions at the first and second location exceeds a limit value.

[0032]

[0026] Directional information in this disclosure refers to the intended state of use of the device according to the invention, in which the device is located on a track arranged horizontally, ie perpendicular to the acceleration due to gravity.

[0033]

[0027] In a preferred embodiment of the invention, it is possible to determine the fastening quality of both rails of a track, in particular if a further first transmission element and a further first pressure element are provided.

[0034]

[0028] In a first embodiment of the invention, the detection of the movement reactions of the rail at the first location and at the second location is carried out by means of a measurement of the first contact pressure and by moving the device from the first to the second location. The first contact pressure is preferably detected as a pressure profile over time. The measurement of the first contact pressure can be used to regulate it in accordance with the first static target pressure. The movement reaction of the rail acts back on the first transmission element and the first contact pressure element, so that a dynamic pressure component is superimposed on the static target pressure by the movement reaction of the rail. This dynamic pressure component is related to the movement reaction of the rail, so that the movement reaction of the rail can be detected by measuring the first contact pressure.A larger range of motion of the rail due to a defective rail fastening leads to a higher amplitude of the dynamic pressure component. Furthermore, a defective rail fastening can also lead to a phase shift in the dynamic pressure component.

[0035]

[0029] The first contact pressure can be measured in or on the first contact pressure element. If the first contact pressure element is a hydraulic and / or pneumatic cylinder, the fluid can be measured, for example, in the pressure chamber or at its inlet or outlet. If several first contact pressure elements are provided, the first contact pressure of each of these first contact pressure elements can be measured. The first contact pressure can, but does not necessarily have to, be used directly to record the movement response. The movement response of the rail also affects variables related to the first contact pressure, which can also be referred to as variables derived from the first contact pressure. Such a derived variable can, for example, be a controller input variable or control deviation, or a control variable for the first contact pressure.“By measuring the first contact pressure” therefore means that the measurement of the first contact pressure can also indirectly serve to record the movement reaction. In the case of a further first transmission element that is connected to the first contact pressure element, the movement reaction of the further rail can also be recorded by measuring the first contact pressure. If a further first contact pressure element and a further first transmission element are present, it can be provided that the movement reactions of the further rail at the first point and at the second point on the further rail are recorded by measuring the further first contact pressure and by moving the device from the first to the second point on the further rail.

[0036]

[0030] In order to be able to easily compare the movement response of a rail at the first location with the movement response at the second location, it is advantageous if only the dynamic components of the movement responses, in particular the first contact pressure or a variable derived therefrom, are taken into account when comparing the movement response of the rail at the first location with the movement response of the rail at the second location. In this way, any similarities between the static components of the movement responses at the first and second locations are ignored, so that errors in the rail fastening can be reliably detected. The static component can be filtered, for example, using low-pass filtering. Since the first static target pressure is known, it can be subtracted from the measured first contact pressure as an alternative to low-pass filtering if the first contact pressure is used directly.The statements also apply accordingly if multiple first contact pressure elements are present, in particular also for the additional first contact pressure or a variable derived therefrom. A derived variable of the contact pressure can, as already mentioned, be, for example, a controller input variable or control deviation or a manipulated variable for controlling the first contact pressure.

[0037]

[0031] A particularly reliable embodiment of the invention results when the comparison of the movement response of the rail at the first location with the movement response of the rail at the second location is carried out by mathematically linking the first contact pressure or a variable derived therefrom with itself, taking into account a time shift, in particular by an autocorrelation function of the first contact pressure or the variable derived therefrom. The mathematical link is preferably a multiplicative link, in particular in combination with a temporal integration. The mathematical link is preferably normalized. An autocorrelation function is particularly preferably used. As already explained, a derived variable can be, for example, a controller input variable or control deviation or a manipulated variable for controlling the first contact pressure.The time shift preferably corresponds to the time period between the detection of the movement reaction at the first and second locations. In this case, particularly in the case of periodic mechanical movements, a phase shift in the movement reaction can be compensated for, which is not due to the rail fastening quality, but merely to the time interval due to the displacement of the movable device between the first and second locations. This can be done, for example, by taking into account the phase positions of the detected movement reactions at the first and second locations in relation to the phase position of the mechanical movement.

[0032] Alternatively, the phase shift can be due to the distance traveled orThe time interval between the comparison of the movement reactions at the first and second locations can be compensated for by determining the phase shift based on the distance traveled or the time elapsed between the comparison of the movement reactions on the basis of a signal from the movement unit, in particular a rotation angle signal, and thus correcting the phase of the movement reaction at the second location. In this way, errors in the evaluation of the rail fastening can be avoided. The statements also apply accordingly if several first contact pressure elements are present, in particular also for the further first contact pressure or a variable derived therefrom.

[0038]

[0033] In one embodiment of the invention, the device can be moved along the track, the first contact pressure can be recorded, and, taking into account the time shift between the measurement at the first and second location, which results from the movement speed of the device and the distance between the first and second location, the temporal progression of the first contact pressure can be mathematically linked to itself, in particular autocorrelated. For autocorrelation, for example, the general formula Equation 1 where T is the autocorrelation signal, T is the time shift between the comparison of the movement reactions at the first and second location, T is a time period, and Pl(t) is the temporal pressure curve of the first contact pressure. For periodic signals, the formula Equation 2 can be used, where T in this case denotes the period of the vibrational movement. The autocorrelation can be calculated by dividing equations 1 and 2 by M J p 1P1 (0). A normalized autocorrelation function is preferred. For PI (t), only the dynamic pressure components can be used.

[0039]

[0034] In a second embodiment of the invention, a second transmission element, in particular a second roller, is provided, which is offset from the first transmission element in the longitudinal direction of the rail and is pressed against the rail by means of a second pressure element, wherein the second pressure element generates a second contact pressure according to a second static target pressure, and the detection of the movement reactions of the rail at the first location and at the second location takes place by measuring the first and second contact pressures. This makes it easy to generate and detect the movement reaction of the rail at two different locations. Displacement of the device is not necessary for this purpose, but is advantageous in order to check the rail and its fastening over a certain distance. The first and second transmission elements are spaced apart from one another in a direction of travel of the device.The distance between the first and second transmission elements can be at least 60 cm, preferably at least 100 cm, particularly preferably at least 140 cm. The second static target pressure can essentially correspond to the first static target pressure. The second transmission element can be designed in the same way as the first transmission element. As already explained in connection with the first transmission element, the second transmission element can be pressed outwards against an inner side of the rail when viewed from the center of the track in a plan view of the track. As already mentioned above, a further first transmission element and a further second transmission element can also be provided, which can be connected to the first or second pressing element or to a further first or further second pressing element. In this case, the explanations also apply mutatis mutandis to these pressing elements and transmission elements.

[0035] In order to be able to compare the movement reactions of the rails at the first and second locations more easily, it is advantageous if only the dynamic components of the movement reactions, in particular the first and second contact pressures or a variable derived therefrom, are taken into account when comparing the movement reaction of the rail at the first location with the movement reaction of the rail at the second location. A low-pass filter can be used to filter the static component. Since the static target pressure is known, if the contact pressure is used directly for the comparison of the movement reactions, it can be subtracted from the measured contact pressure as an alternative to low-pass filtering. As already mentioned, a derived variable can be, for example, a controller input variable or control deviation or a manipulated variable for controlling the first contact pressure.The statements also apply accordingly if a further first contact pressure element and a further second contact pressure element are present, in particular also for the further first and further second contact pressure or a variable derived therefrom.

[0040]

[0036] It is advantageous if the comparison of the movement response of the rail at the first point with the movement response of the rail at the second point is carried out by mathematically linking the first and second contact pressures or a variable derived therefrom, in particular by a cross-correlation function. The mathematical link is preferably a multiplicative link in combination with temporal integration. A cross-correlation function is particularly preferably used. However, convolution is also possible. A derived variable can, for example, be a controller input variable or control deviation or a manipulated variable for controlling the first contact pressure. The statements also apply mutatis mutandis if a further first contact pressure element and a further second contact pressure element are present, in particular also for the further first contact pressure and the further second contact pressure or a variable derived therefrom.For cross-correlation, for example, the general formula Equation 3 can be used. where T is the cross-correlation signal, T is a time shift, T is a time duration, PI (t) is the temporal pressure profile of the first contact pressure, and P2(t) is the temporal pressure profile of the first and second contact pressure. Since the mechanical movement is transmitted simultaneously from the two transmission elements to the rail, T = 0 can be assumed, so that equation 3 becomes equation 4. simplified. For periodic signals, the formula Equation 5 or Equation 6 can be used, where T in this case denotes the period. The cross-correlation can be calculated by dividing equations 1 and 2 by ( P1P1 (0) * P2P2 (0)) 1 / 2(see autocorrelation above). A normalized cross-correlation function is preferred. For PI(t) and P2(t), only the dynamic pressure components can be used.

[0041]

[0037] In order to assess the rail fastening of a track along a section of the railway line, it is advantageous if the mathematical linkage is performed continuously or repeatedly at intervals while the movable device is moved along the track. In this case, first and second locations on the rail can be continuously determined, and if a further first and second transmission element are present, on the further rail.

[0042]

[0038] In order to be able to evaluate the rail fastening quality equally at all locations, it is advantageous if the mathematical link is standardized and a fault in the rail fastening is detected if the absolute value of the mathematical function is below a limit value, preferably where the limit value is between 0.75 and 0.95. Standardization allows the rail fastening quality to be assessed uniformly. In one example, the mathematical link is standardized to the product of the largest expected values ​​of the movement reactions at the first and second locations. An autocorrelation and a cross-correlation function can be standardized as indicated above.

[0043]

[0039] A particularly advantageous embodiment of the invention results when the mechanical movement is a vibration movement with a frequency between 20 Hz and 40 Hz, preferably between 25 Hz and 35 Hz. Tests have shown that it is advantageous if the amplitude of the vibration movement is selected such that a horizontal movement of a properly fastened rail head has an amplitude of 1 mm to 2 mm.

[0044]

[0040] The above-mentioned object is also achieved by a system for checking a fastening of a rail of a track according to claim 11. The system comprises:

[0045] - a device movable along the track, in particular a device for compacting a ballast bed of a track, comprising:

[0046] - a frame;

[0047] - at least one first transmission element, preferably a first roller, in particular a flanged roller;

[0048] - a movement unit on the frame for generating a mechanical movement, in particular a vibratory movement;

[0049] - a first contact pressure element configured to generate a first contact pressure according to a first static target pressure and to press the at least one transmission element against the rail of the track, so that the mechanical movement is transmitted to the rail; - a detection unit for detecting a movement reaction of the rail as a result of the mechanical movement;

[0050] - an evaluation unit which is designed to compare the movement reaction of the rail at a first location with the movement reaction of the rail at a second location and to evaluate the rail fastening on the basis of the comparison.

[0051]

[0041] The system according to the invention is configured to carry out the method described above for checking the fastening of a rail of a track. The features and advantages described above in connection with the method are therefore transferable to the system. The at least one first transmission element, the movement unit, the at least one first pressure element, and the detection unit can be fastened directly or indirectly to the frame. In one embodiment of the invention, the evaluation unit can also be fastened directly or indirectly to the frame. In an alternative embodiment, the evaluation unit is designed as a remote evaluation unit that is not arranged on the device, but at a remote location or on a higher-level rail vehicle (see below). The evaluation unit can be connected to the detection unit by cable or wirelessly.The evaluation unit can be formed by a microprocessor, a computer, or a server. The detection unit can have an optical, an inductive, a capacitive, and / or an electromechanical sensor. In a particularly preferred embodiment, the detection unit has at least one pressure measuring sensor that measures the first contact pressure of the first contact pressure element. The first transmission element is preferably a rotatable roller, but can also be formed, for example, by a block. The device can have its own drive for moving the device, for example an electric motor, or form part of a higher-level rail vehicle that can move the device. As described above in connection with the method, a further first transmission element can also be provided, which is connected to the first contact pressure element or to a further contact pressure element.

[0052]

[0042] In one embodiment of the invention, the first pressure element is formed by a hydraulic and / or pneumatic cylinder. The hydraulic and / or pneumatic cylinder can transmit the desired pressure to the rail via the first transmission element. The hydraulic and / or pneumatic cylinder can be arranged substantially horizontally, i.e., substantially transversely to the acceleration due to gravity. If a second pressure element is provided, this can also be formed by a hydraulic and / or pneumatic cylinder, in particular of a similar type. Any further first or second pressure elements can also be formed by a hydraulic and / or pneumatic cylinder and preferably arranged horizontally.

[0053]

[0043] In order to detect the movement reaction of the rail, the detection unit can be provided with a pressure sensor in or on the hydraulic and / or pneumatic cylinder. If several pressure elements are provided, which are formed by a hydraulic and / or pneumatic cylinder, a separate pressure sensor can be provided in or on each hydraulic and / or pneumatic cylinder. A pressure sensor can measure the contact pressure of the pressure element assigned to it.

[0054]

[0044] In a preferred embodiment of the invention, at least one second pressing element can be provided, offset from the first pressing element in a direction of travel of the device, which is configured to generate a second contact pressure according to a second static target pressure and to press the second transmission element against the rail of the track. The second pressing element is preferably arranged horizontally. The second pressing element and the first pressing element can be of similar design.

[0055] Advantageously, the rail can be set in motion at two points simultaneously by two pressure elements offset in the direction of travel. The second pressure element can also be designed as a hydraulic and / or pneumatic cylinder. Any further second pressure elements (see above) can also be formed by a hydraulic and / or pneumatic cylinder. A further second transmission element can also be provided. The further second transmission element can also be pressed against the further rail by the second pressure element or by a further second pressure element. In the case of a further second pressure element, this generates a further second contact pressure according to a further second static target pressure, which is preferably identical to the second static target pressure.

[0056]

[0045] In order to be able to adjust a vertical compressive load on the track, at least one load-pressure element can be provided, with which a vertical contact force on the rail can be adjusted. This embodiment is particularly advantageous when the device forms part of a rail vehicle. The load-pressure element can also be formed by a hydraulic and / or pneumatic cylinder.

[0057] Short description of the drawings

[0058]

[0046] The invention is explained in more detail below with reference to figures, to which, however, it is not intended to be limited. They show:

[0059] Fig. 1 is a side view of a superordinate rail vehicle moving a movable device of a system for checking the fastening of a rail;

[0060] Fig. 2 shows a movable device of a system for checking a fastening of a rail of a track in a front view;

[0061] Fig. 3 is a schematic representation of a movable device of a system for checking a fastening of a rail of a track in a plan view;

[0062] Fig. 4 shows a movable device of a system for checking the fastening of a rail of a track in a plan view; Fig. 5A shows unfiltered pressure signals, Fig. 5B shows filtered pressure signals, Fig.

[0063] 5C dynamic pressure components of filtered pressure signals;

[0064] Fig. 6 a cross-correlation signal;

[0065] Fig. 7A unfiltered pressure signals,

[0066] Fig. 7B filtered pressure signals,

[0067] Fig. 7C dynamic pressure components of filtered pressure signals;

[0068] Fig. 8A unfiltered pressure signals,

[0069] Fig. 8B filtered pressure signals,

[0070] Fig. 8C dynamic pressure components of filtered pressure signals; and

[0071] Fig. 9A unfiltered pressure signals,

[0072] Fig. 9B filtered pressure signals,

[0073] Fig. 9C dynamic pressure components of filtered pressure signals.

[0074] Description of the embodiments

[0075]

[0047] Fig. 1 shows a master rail vehicle 1 with a rail vehicle drive 2, which travels along a track 3 with two parallel rails 4a, 4b. Between the wheel sets 5 of the master rail vehicle 1, a movable device 6 of a system 7 according to the invention for checking the fastening of the rail 4a, 4b of the track 3 is arranged. The movable device 6 is connected to the master rail vehicle 1, preferably to a chassis 8 of the master rail vehicle 1. The master rail vehicle 1 can move the movable device 6 along the track 3. In another embodiment, the movable device 6 can have its own drive (not shown) and move itself. The movable device 6 is preferably designed as a device for compacting the ballast bed of the track 3 (dynamic track stabilizer 52).

[0076]

[0048] Fig. 2 shows the connection of the movable device 6 to the chassis 8 of the superordinate rail vehicle 1. In the embodiment shown, the movable device 6 has a plurality of load pressing elements 9 in the form of hydraulic cylinders 10, with which a vertical contact force F A the movable device 6 is adjustable to the rails 4a, 4b. Ends 11 of the load pressing elements 9 are connected to the chassis 8 of the superordinate rail vehicle 1. With the load pressing elements 9, the load of the movable device 6 can be adjusted to the rails 4a, 4b.

[0049] As can be seen in Fig. 2, the movable device 6 has a

[0077] Frame 12, on which a movement unit 13 for generating a mechanical movement F v , preferably a periodic vibration movement, and a first pressure element 14 is mounted. The movement unit 13 generates the mechanical movement Fv preferably with one or more unbalanced masses (not shown). Preferably, the mechanical movement F v a frequency between 30 Hz and 40 Hz. A first transmission element 16a and a further first transmission element 16b are connected to the first pressing element 14, which in the embodiment shown is designed as a hydraulic cylinder, at opposite ends 15a, 15b. It is also possible for a first pressing element 14 to be assigned to the first transmission element 16a and a further first pressing element to be assigned to the further transmission element 16b (not shown). The transmission element 16a and the further transmission element 16b are designed as first rollers 17a, 17b and are driven by the first

[0078] Pressing element 14 is pressed against an inner side 18a of the rail 4a facing the track center 21 and against an inner side 18b of the further rail 4b of the track 3 facing the track center 21. For this purpose, the first pressing element 14 generates a first static target pressure Pl S t a tisch_soii, which is exerted on the first transmission elements 16a, 16b. A control can be provided which adjusts the contact pressure PI of the first contact pressure element 14 according to the first static target pressure Pl S t a ti Sch_soii regulates. The movable device 6 is spread between the rails 4a, 4b by the transmission elements 16a, 16b. To further secure the device 6, the embodiment shown includes clamping rollers 19a, 19b on opposite sides. In a fixed position, these rollers rest against the rails 4a, 4b and press on the outer sides 20a, 20b of the rails 4a, 4b toward the track center 21. The clamping rollers 19a, 19b can be moved from the fixed position to a release position by deflection mechanisms 22a, 22b and actuators 23a, 23b.

[0079]

[0050] In order to check the fastening of a rail 4a, 4b of a track 3, which is defined not only by the fixation 50 of the rails 4a, 4b to the sleepers 24, for example by bolts and screws, but also by the tamping 25 of the sleepers 24 with ballast 26, movement reactions R of the rails 4a, 4b as a result of the mechanical movement F transmitted to the rails 4a, 4b v at different, spaced-apart locations 27, 28 on track 3 and compared with each other. The comparison of the movement reactions R at locations 27, 28 reveals differences in the fastening of the rails 4a, 4b. The comparison can be performed in an evaluation unit 51, which can be located, for example, in the parent rail vehicle 1.

[0080]

[0051] In order to be able to determine the movement reactions R of the rails 4a, 4b, the movable device 6 has a detection unit 29 which is connected to the evaluation unit 51. The detection unit 29 can, for example, have an optical, an inductive, a capacitive and / or an electromechanical sensor with which the movement reactions R can be measured. However, it is preferred if, for detecting the movement reactions R, the detection unit 29 has a pressure measuring sensor 30 which measures a first contact pressure PI of the first contact element 14, which is derived from the first static target pressure Pl S t a table_soii u r| d the dynamic pressure component Pl dyn Since the dynamic pressure component Pl dynis influenced by the movement reaction R, the first contact pressure PI allows conclusions to be drawn about the movement reaction R of the rail 4a, 4b. In order to detect the movement reaction R of the rail 4a, 4b at a point 27, 28, the contact pressure PI or a variable derived therefrom, such as a control deviation or a control variable of a control loop for controlling the first contact pressure PI, can be used directly.

[0052] In order to check the fastening of a rail 4a, 4b, it is provided to compare the movement reaction R of the rail 4a, 4b at at least two different points 27, 28. For this purpose, the movable device 6 can be moved from a first point 27 to a second point 28 in a first embodiment of the invention. At the two points 27, 28, the mechanical movement F vare transmitted to the rails 4a, 4b and the movement reaction R at each of the two points 27, 28 is preferably recorded using a pressure measurement of the first contact pressure PI. A time course of the first contact pressure PI is shown, for example, in Fig. 5A. Fig. 7A, Fig. 8A and Fig. 9A show sections of the time course according to Fig. 5A of the first contact pressure PI at different times while the device 6 is moved along a track 3, and thus at different points 27, 28. After the movement reactions R have been recorded, the movement reactions R of the rails 4a, 4b at the points 27, 28 can be compared with one another. For example, the time course of the first contact pressure PI according to Fig. 7A (exemplary first point 27) can be compared with the time course of the first contact pressure PI according to Fig. 8A (exemplary second point 28).In order to detect deviations in the movement reactions R, preferably only the dynamic pressure components Pl are used. dyn of the contact pressure PI at points 27 and 28 were compared. Dynamic pressure components Pl dyn of the first contact pressure PI are shown in Fig. 70, Fig. 80 and Fig. 90. If a deviation, in particular in amplitude Al, A2 and / or phase 1, 2, of the dynamic pressure components Pl dyn is present, it can be concluded that a rail 4a, 4b is defectively fastened at one of the points 27, 28. If, for example, the deviation in amplitude A1, A2 or phase O1, O2 exceeds a limit, it can be assumed that the rail fastening at one of the points 27, 28 is defective.

[0081]

[0053] The movement reaction R of the rails 4a, 4b is recorded as a time profile (see the time profile of the first contact pressure P1 in Fig. 5A). In the first embodiment described, the contact pressure P1 or a variable derived therefrom, such as a manipulated variable or a control deviation, is compared with itself at different times at which the device is located at the points 27, 28. Preferably, as described, only the dynamic components of the first contact pressure P1 are used for this comparison (see Fig. 50). The comparison can be made, for example, on the basis of an autocorrelation function or another multiplicative and preferably integral mathematical operation.In order to avoid errors when checking the rail fastening, it is advantageous to compensate for a phase shift in the movement reaction R, which is not due to any defective rail fastening, but rather to the temporal and spatial distance between the positioning of the device 6 at the first location 27 and the second location 28. This can be achieved, for example, by taking into account the phase positions of the recorded movement reactions R at the first location 27 and the second location 28 relative to the phase position of the mechanical movement F. vAlternatively, the phase shift can be compensated for based on the distance traveled or the time interval between the comparison of the movement reactions R at the first location 27 and the second location 28 by determining the phase shift based on the distance traveled or the time elapsed between the comparison of the movement reactions R on the basis of a signal from the movement unit 13, in particular a rotation angle signal, and thus correcting the phase of the movement reaction.

[0082]

[0054] In a second embodiment of the invention, a second pressure element 31 and two second transmission elements 32a, 32b in the form of second rollers 33a, 33b are provided. This is shown in Fig. 3 or Fig. 4. The second pressure element 31 is essentially the same as the first pressure element 14 and is designed to generate a second static target pressure P2 statisch _ soNwhich essentially corresponds to the first static target pressure Pl S tatisch_soii corresponds. The second pressing element 31 presses the first transmission element 32a against the inner side 18a of the rail 4a and the further second transmission element 32b against the inner side 18b of the further rail 4b. As a result, the movable device 6 is spread at two points 27, 28 in the track 3 and the mechanical movement F v at the two points 27, 28 onto the rails 4a, 4b. The distance between the first transmission element 16a and the second transmission element 32a is preferably at least 60 cm. The same applies to the other transmission elements 16b, 32b. The first pressing element 14 and the first transmission elements 16a, 16b are essentially the same as the second pressing element 31 and the second transmission elements 32a, 32b. Due to the fact that in the second embodiment of the invention the mechanical movement F vBy means of the first 14 and second contact pressure elements 31, the movement reactions R at the two locations 27, 28 can also be recorded and compared with each other. As already explained in the first embodiment, the movement reaction R of the rails 4a can be recorded using the first contact pressure P1. Accordingly, the movement reaction of the rails 4a, 4b can also be recorded using the second contact pressure P2.

[0083]

[0055] Advantageously, the movable device 6 does not need to be moved to detect the movement reaction R at different locations 27, 28. However, in order to check the fastening of a longer track section, it may be advantageous to move the movable device 6 and thereby continuously define new first 27 and second locations 28 on track 3.

[0084]

[0056] Fig. 5A-C show time courses of the contact pressures P1 and P2 while the movable device 6 is moved. The abscissa of Fig. 5A-C describes a time t in s. The ordinate of Fig. 5A-C describes a pressure P in bar. During the illustrated time of approximately 60 seconds, the movable device 6 according to the second embodiment is moved along a track section of the track 3 and the first contact pressure P1 and the second contact pressure P2 are measured. Fig. 5A shows the time course of the unfiltered contact pressures P1, P2. Fig. 5B shows the time course of the contact pressures P1, P2 after a low-pass filtering, which is referred to as P1 fHt and P2 fHt The cutoff frequency of the low-pass filter lies just above an excitation frequency of the mechanical movement F vbetween 25 Hz and 40 Hz. Fig. 50 shows the time course of the contact pressures Pl, P2 after deducting the static pressure component Plstatic-so„ or P2static soll, i.e. Pl dyn and P2 dyn By comparing the dynamic pressure components at different points 27, 28, which are continuously re-determined during the movement of the movable device 6 and determined by the distance between the first 16a, 16b and second transmission elements 32a, 32b, conclusions can be drawn about the fastening of the rails 4a, 4b of track 3. In particular, deviations in amplitude A1, A2 and phase O1, O2 indicate deficiencies in the fastening of the rails 4a, 4b.

[0085]

[0057] In order to efficiently compare the motion reactions R at points 27, 28, it is advantageous to mathematically link the first contact pressure PI and the second contact pressure P2 or a value derived therefrom. It is particularly advantageous if the contact pressures Pl, P2 are linked to each other using a preferably normalized cross-correlation function. A normalized cross-correlation Corr of the dynamic pressure components Pl dyn and P2 dynaccording to Fig. 5C is shown in Fig. 6. The abscissa indicates time t in seconds. The ordinate describes a scale from 0 to 1. In Fig. 6, it can be seen that the cross-correlation value at approximately t = 31 seconds falls below an exemplary limit value S = 0.9 to approximately 0.82. This is an indication that the fastening of the rails 4a, 4b at one of the two points 27, 28 defined at this time may be inadequate. In Fig. 6, three time periods 34, 35, and 36 are marked. The unfiltered and filtered contact pressures Pl, P2 as well as the dynamic pressure components Pl dyn and P2 dyn These time periods are shown in more detail in Figures 7A-C, 8A-C, and 9A-C. Figures 7A-C, 8A-C, and 9A-C thus represent sections of Figures 5A-C.

[0086]

[0058] Fig. 7A-C shows the time range 34. The abscissa of Fig. 7A-C represents the time t in seconds. The ordinate represents the pressure P in bar. Fig. 7A shows, similar to Fig. 5A, the time course of the unfiltered contact pressures Pl, P2. Fig. 7B shows the time course of the contact pressures Pl, P2 after a low-pass filtering, which is referred to as Pl fHt and P2 fHt Fig. 7C shows the time course of the filtered contact pressures Pl fHt and P2 fHt after deducting the static pressure component Plstatic-soii or P2static soll, i.e. Pl dyn and P2 dyn . It can be seen that the dynamic pressure components Pl dyn and P2 dyn In phase 0, 1 and 2 essentially coincide. The amplitudes A1 and A2 differ slightly but harmlessly.

[0087]

[0059] Fig. 8A-C shows the time range 35. The abscissa of Fig. 8A-C represents the time t in seconds. The ordinate represents the pressure P in bar. Fig. 8A shows, similar to Fig. 5A, the time course of the unfiltered contact pressures Pl, P2. Fig. 8B shows the time course of the contact pressures Pl, P2 after a low-pass filtering, which is referred to as Pl fHt and P2 fHt Fig. 80 shows the time course of the filtered contact pressures Pl fHt and P2 fHt after deducting the static pressure component Plstatic-soii or P2static soll, i.e. Pl dyn and P2 dyn . It can be seen that the dynamic pressure components Pl dyn and P2 dyn in the phase 0 1, 0 2 and amplitude Al, A2 differ significantly from each other, which leads to a significant reduction of the value in the cross-correlation (see Fig. 6, time range 35).

[0088]

[0060] Fig. 9A-C shows the time range 34. The abscissa of Fig. 9A-C represents the time t in seconds. The ordinate represents the pressure P in bar. Fig. 9A shows, similar to Fig. 5A, the time course of the unfiltered contact pressures Pl, P2, which are referred to as Pl fHt and P2 fHt Fig. 9B shows the time course of the contact pressures Pl, P2 after low-pass filtering. Fig. 90 shows the time course of the filtered contact pressures Pl fHt and P2 fHt after deducting the static pressure component Plstatic-soii or P2static soll, i.e. Pl dyn and P2 dyn . It can be seen that the dynamic pressure components Pl dyn and P2 dyn In phase 0, 1 and 2 essentially coincide. The amplitudes A1 and A2 differ slightly but harmlessly.

Claims

Patent claims 1. Method for checking the fastening of at least one rail (4a, 4b) of a track (3) comprising the following steps: Generating a mechanical movement (F v ), in particular a vibratory movement, by a movement unit (13) which is arranged on a device (6) which can be moved along the track (3); Pressing at least one first transmission element (16a, 16b) of the movable device (6), in particular a first roller (17a, 17b), onto the rail (4a, 4b) by means of at least one first pressing element (14), wherein the first pressing element (14) has a first contact pressure (PI) according to a first static target pressure (Pl S tatisch_soii) is generated; Transmission of mechanical movement (F v ) onto the rail (4a, 4b); Recording the movement reactions (R) of the rail (4a, 4b) as a result of the mechanical movement (F v) at a first location (27) and at a second location (28), the locations (27, 28) being spaced apart from one another in the longitudinal direction of the rail (4a, 4b); Comparing the movement reaction (R), in particular amplitude (Al, A2) and phase position (0 1, 02), of the rail (4a, 4b) at the first location (27) with the movement reaction (R), in particular amplitude (Al, A2) and phase position (1, 0 2), of the rail (4a, 4b) at the second location (28); and Evaluating the rail fastening based on the comparison of the movement reaction (R) of the rail (4a, 4b) at the first location (27) with the movement reaction (R) of the rail (4a, 4b) at the second location (28).

2. Method according to claim 1, characterized in that the detection of the movement reactions (R) of the rail (4a, 4b) at the first location (27) and at the second location (28) is carried out by means of a measurement of the first contact pressure (PI) and by moving the device (6) from the first location (27) to the second location (28).

3. Method according to claim 2, characterized in that for the comparison of the movement reaction (R) of the rail (4a, 4b) at the first location (27) with the movement reaction (R) of the rail (4a, 4b) at the second point (28) only the dynamic components of the movement reactions (R), in particular the first contact pressure (PI) or a value derived therefrom, are taken into account.

4. Method according to claim 2 or 3, characterized in that the comparison of the movement reaction (R) of the rail (4a, 4b) at the first point (27) with the movement reaction (R) of the rail (4a, 4b) at the second point (28) by mathematically linking the first contact pressure (PI) or a variable derived therefrom with itself, taking into account a time shift, in particular by an autocorrelation function of the first contact pressure (PI) or the variable derived therefrom.

5. Method according to claim 1, characterized in that a second transmission element (32a, 32b), in particular a second roller (33a, 33b), is provided, which is offset from the first transmission element (16a, 16b) in the longitudinal direction of the rail (4a, 4b) and is pressed against the rail (4a, 4b) by means of a second pressing element (31), wherein the second pressing element (31) generates a second contact pressure (P2) according to a second static desired pressure (P2static soN) and the detection of the movement reactions (R) of the rail (4a, 4b) at the first point (27) and at the second point (28) is carried out by means of a measurement of the first (P1) and the second contact pressure (P2).

6. Method according to claim 5, characterized in that for the comparison of the movement reaction (R) of the rail (4a, 4b) at the first location (27) with the movement reaction (R) of the rail (4a, 4b) at the second point (28) only the dynamic components of the movement reactions (R), in particular the first (PI) and the second contact pressure (P2) or a value derived therefrom, are taken into account.

7. Method according to one of claims 5 or 6, characterized in that the comparison of the movement reaction (R) of the rail (4a, 4b) at the first location (27) with the movement reaction (R) of the rail (4a, 4b) at the second location (28) by a mathematical combination of the first (PI) and the second contact pressure (P2) or a value derived therefrom, in particular by a cross-correlation function.

8. Method according to claim 4 or 7, characterized in that the mathematical operation is carried out continuously or several times at time intervals while the movable device (6) is moved along the track (3).

9. Method according to one of claims 4, 7 or 8, characterized in that the mathematical operation is standardized and a fault in the rail fastening is detected if the absolute value of the mathematical function is below a limit value, preferably wherein the limit value is between 0.75 and 0.

95.

10. Method according to one of claims 1 to 9, characterized in that the mechanical movement (F v ) is a vibratory movement with a frequency between 20 Hz and 40 Hz, preferably between 25 Hz and 35 Hz.

11. System (7) for checking the fastening of a rail (4a, 4b) of a track (3), comprising: a device (6) movable along the track (3), in particular a device (52) for compacting a ballast bed of a track (3), comprising: a frame (12); - at least one first transmission element (16a, 16b), preferably a first roller (17a, 17b), in particular a flanged roller; a movement unit (13) on the frame (12) for generating a mechanical movement (F v ), in particular a vibrating movement; - at least one first contact pressure element (14) which is designed to generate a first contact pressure (PI) according to a first static target pressure (Plst a tisch_soii) zu generate and the first transmission element (16a, 16b) to the rail (4a, 4b) of the track (3) so that the mechanical movement (F v ) is transmitted to the rail (4a, 4b); a detection unit (29) for detecting a movement reaction (R) of the rail (4a, 4b) as a result of the mechanical movement (F v); an evaluation unit (51) which is designed to compare the movement reaction (R) of the rail (4a, 4b) at a first location (27) with the movement reaction (R) of the rail (4a, 4b) at a second location (28) and to evaluate the rail fastening on the basis of the comparison.

12. System (7) according to claim 11, characterized in that the first pressing element (14) is formed by a hydraulic and / or pneumatic cylinder.

13. System according to claim 12, characterized in that the detection unit has a pressure measuring sensor (30) in or on the hydraulic and / or pneumatic cylinder.

14. System (7) according to one of claims 11 to 13, characterized in that a second pressing element (31) is provided which is offset in a direction of travel of the device (6) relative to the first pressing element (14), and which is designed to generate a second contact pressure (P2) in accordance with a second static target pressure (P2 statisch _soN ) and to press the second transmission element (32a, 32b) onto the rail (4a, 4b) of the track (3).

15. System (7) according to one of claims 11 to 14, characterized in that at least one load pressing element (9) is provided, with which a vertical pressing force (F A ) is adjustable onto the rail (4a, 4b).

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