System and vehicle for capturing the position and geometry of track infrastructure, especially for a railway line

Abstract

Data acquisition system (1) for track infrastructure (C, P, L, ST, B, BL) of a railway line, comprising: - at least one electromagnetic wave detection device (2, 2A, 2B) comprising at least one transmit-receive antenna, wherein the electromagnetic wave detection device (2, 2A, 2B) is configured to emit electromagnetic waves towards a track infrastructure (C, P, L, ST, B, BL) by means of the at least one transmit-receive antenna and to receive electromagnetic waves reflected from the track infrastructure (C, P, L, ST, B, BL); and - a control unit configured to process the electromagnetic waves reflected by the track infrastructure (C, P, L, ST, B, BL) and to determine a position of the track infrastructure (C, P, L, ST, B, BL) relative to a preset reference system, wherein the at least one electromagnetic wave detection device (2, 2A, 2B) is configured for installation on board a rail vehicle (V), and wherein the at least one electromagnetic wave detection device (2, 2A, 2B) comprises a phased array radar incorporating a plurality of transmit-receive antennas.

Description

Field of invention

[0001] The present invention relates to diagnostic systems for railway infrastructure, in particular systems for detecting and monitoring track infrastructure such as overhead lines, overhead line support poles, and ballast profile. Background documents in this field include, among others, CN 107 678 036 A, WO 97 / 31810 A1, and US 2018 / 329052 A1. State of the art

[0002] In railway infrastructure, determining the position of the contact wire and the overhead line's weight-bearing cable relative to the rail is crucial to ensure they are correctly positioned for contact with the pantograph of rail vehicles. Incorrect contact geometry can actually cause the pantograph to become inadvertently caught in the wires, most likely resulting in damage to both. With reference to Fig. Figure 1 includes an overhead line C, a weight-bearing cable, or a catenary P, from which a contact wire L is suspended by means of a multitude of pantographs S. The contact wire L can be a single wire, as is the case, for example, in the cross-sectional view of Fig. 2 is, or double, as in the case of the cross-sectional view of Fig. 3. If Z denotes the vertical axis centered at the midpoint of the track gradient, the overhead line C can be positioned at a distance from the centerline, either on one side or on the other. This means either that it can be located at a distance from the centerline on only one side, or that it runs from one side of the centerline to the other. Currently, there are instruments for measuring the position of the contact wire L and the weight-bearing cable P relative to the track, based on a contact system.These are contact sensors, typically added to the pantograph of a diagnostic vehicle, to measure the height of the contact wire L and, in certain cases, its lateral position relative to the center of the rail. This position can vary depending on the development of the overhead line in the plane of the rails (axis Y), the presence of switches or crossings, or simply as a result of thermal expansion compensation using tension weights, or for any number of other reasons. Furthermore, another disadvantage, albeit a partial one, lies in the fact that this instrument is only capable of measuring the position of the overhead line under operating conditions, when the wire L is displaced relative to its resting position due to interaction with the pantograph.Of course, measuring the position under operating conditions is of some interest for diagnostic purposes, but it is the resting position that is more interesting, as it is the latter that allows for prognostic activity regarding potential problems while the rail vehicle is in motion. Furthermore, there are numerous non-contact measuring instruments designed to measure the position of one or more wires L, depending on their type. When instruments are installed near a pantograph, they can measure both the position under the pantograph's pressure (i.e., when the pantograph is raised) and the static or resting position (i.e., when the pantograph is lowered). These instruments are predominantly optical and based on rotating scanners (LiDARs) or various types of optical triangulation.While sufficiently accurate and potentially capable of monitoring overhead power lines not strictly under working conditions, the main drawback of these instruments is contamination. Being optical devices, they require transparent or, at the very least, refractive windows through which the actual measurement is taken. Since these windows are invariably located in sections exposed to harsh weather conditions on the railway, they are subject to extremely rapid deterioration in performance due to atmospheric contamination and / or contamination resulting from the accumulation of material shed by the moving railway, such as grease, dirt, and fluids. Capturing a cross-sectional profile of the ballast on the gradient is also an important consideration, although relatively independent of the above.The ballast is the layer of crushed stone that holds the sleepers, and therefore the rail, to the ground. The height of the ballast relative to the sleepers is a rather critical parameter: it must be sufficient to hold the rail to the ground, but not excessive, both to avoid wasting material and to prevent stones, lifted by air displacement due to train passage, from damaging the train or the infrastructure. Optical instruments are currently used to determine the ballast profile, but these suffer from the same problems mentioned above. Object of the invention

[0003] The object of the present invention is to solve the aforementioned technical problems. In particular, the object of the present invention is to provide a system for detecting the position of track infrastructure, such as overhead lines, support poles, and ballast profiles, which enables operation in a manner that is essentially insensitive to contamination by atmospheric agents or contamination resulting from the movement of the vehicle itself. Summary of the invention

[0004] The object of the present invention is achieved by a system and a rail vehicle having the features that form the subject matter of the following claims, which form an integral part of the technical disclosure provided herein in relation to the invention. Brief description of the characters

[0005] The invention will now be described with reference to the attached figures, which are provided purely as a non-limiting example and in which: - Fig. 1 to Fig. Figures 3, which have already been described, illustrate an overhead line or two characteristic cross-sections thereof; - Fig. 4 and Fig. 5 conditions are illustrated as an example of the displacement of track infrastructure in relation to the center of the plane of the rails; - Fig. 6 and Fig. 7 illustrate two embodiments of the measuring system according to the invention; - Fig. 8 and Fig. 9 two views (a side view or a perspective view) of a further embodiment of the measuring system according to the invention are; - Fig. 10 and Fig. 11 illustrates a further embodiment of the system according to the invention in a perspective view or in a top view; - Fig. 12 and Fig. 13 illustrate yet another embodiment of the invention; and - Fig. Figure 14 illustrates a further embodiment of the invention, which is configured in particular to capture a profile of the gravel on the slope. Detailed description

[0006] In Fig. 6 and Fig. Reference numeral 7 denotes a detection system for railway infrastructure according to various embodiments of the invention. The detection system 1 comprises at least one electromagnetic wave detection device 2, which in turn comprises at least one transmitting / receiving antenna.

[0007] In some embodiments, such as the one in Fig. As illustrated in Figure 7, the detection system can comprise two electromagnetic wave detection devices, designated by reference numerals 2A and 2B. The at least one transmitting / receiving antenna of each device 2, 2A, 2B is configured to emit electromagnetic waves towards a track infrastructure and to receive electromagnetic waves reflected from the track infrastructure. System 1 is expediently mounted on the roof of a railway vehicle, but other locations are possible depending on the track infrastructure to be detected.

[0008] In a preferred embodiment, the detection device 2 comprises a phased-array radar containing a plurality of transmit-receiver antennas that are sequentially supplied with a preset phase delay, such that the overall wavefront is capable of traversing an angle β with an amplitude sufficient to cover the range of variability of the overhead line C positions of interest for the specific application. In a phased-array radar, supplying the array of transmit-receiver antennas with signals exhibiting a preset phase difference generates a wavefront with a known angular phase shift relative to the axis of the radar itself. This means that by varying the phase shift over time, it is possible to traverse the angle β, thereby defining the operating range of the device 2.

[0009] System 1 further comprises an electronic control unit (CU) configured to receive a signal representing the electromagnetic wave reflected and received by the transmit-receiver antennas of device 2 and to determine the position of the link infrastructure relative to a preset reference system. In general, the electronic control unit (CU) receives a set of signals containing information regarding both the emitted and reflected electromagnetic waves. Since processing the signal data relating to the reflected electromagnetic waves is particularly complex, this processing is performed using dedicated computing units (such as DSPs + RISC CPUs and possibly FPGAs).

[0010] As in Fig. 6 and Fig. 7 and in the following Fig. 8 and Fig. As shown in Figure 11, System 1 is configured for use on board a rail vehicle V, which can be either a diagnostic vehicle or a completely conventional passenger or freight rail vehicle, such as a passenger car, express train, freight car, locomotive, or even a passenger-powered railcar (e.g., a handcart or a jigger). When installed on board a rail vehicle, System 1 is further configured to work in conjunction with an encoder 3 (or, more generally, any angular position converter) connected to a wheelset of a bogie of the rail vehicle (for example, integrated into a position corresponding to an axle box of the bogie), thus providing synchronization of the data acquired by the device 2 with the movement of the vehicle along the plane of the rails.

[0011] In particular, each measurement by the device 2 is initiated by a pulse, which also triggers the reading of the pulse counter of the encoder 3. This makes it possible to provide the measurement with a mileage reference along the track on which the vehicle V is traveling, and it is also possible to measure the distance traveled by the vehicle V itself. The reading by the device 2 is extremely fast, and the device 2 is designed to operate effectively at speeds up to approximately 300 km / h.

[0012] With reference to Fig. 6. A system 1 according to the invention, in which there is a single detection device 2, can always be used when it is necessary to measure only the position of one or more contact wires L of the overhead line C. The solution of Fig. 7 is preferable instead if it is desired to also measure the overhead contact line cable P, which may be obscured by a contact wire L when the system 1 is located directly beneath it. In the event that the track has any feature of geometric irregularity or singularity, or to prevent partial or incomplete detection due to the fact that the weight-bearing cable P of the overhead line may be obscured by the wire L, or again due to the fact that with a double wire L, one of the two wires may be obscured by the other – again taking into account the installation of the detection system 1 on the roof of a rail vehicle – the system 1 is to be configured according to the representation of Fig. 7. Constructed more appropriately, i.e., with at least two electromagnetic wave detection devices 2A, 2B (preferably phased-array radars) arranged on opposite sides of the vehicle V and having reciprocal axes of incidence. In this way, any object that is obscured from one of the two radars 2A, 2B will not be obscured from the other.

[0013] In some embodiments of System 1, however, it is necessary to detect the return echoes of each radar 2A, 2B in order to prevent false detection events. One solution is to supply radars 2A, 2B with signals having different frequencies, such that the signals corresponding to the reflected electromagnetic waves are filtered by filters sensitive to these frequencies, thus easily distinguishing the echoes of radar 2A from those of radar 2B. A second possibility is to control radars 2A, 2B (and any additional radar 2 that can form the instrument 1) using the so-called time-division technique, i.e., to assign each radar 2A, 2B a window that operates within a given time interval in order to have a two-way correspondence between the specific time and the emitted and reflected electromagnetic waves.In other words, in this case there is certainty that at any given time one and only one radar of the arrangement of system 1 is operating according to the radar activation sequence.

[0014] In further embodiments, it is possible to control radars 2A, 2B, and other possible radars of system 1 in such a way that the two control techniques—variable frequency and time division—are combined. With reference to Fig. In a further embodiment of the invention, the system 1 is configured, in particular, for measuring the position and detecting the geometry of supports that carry the overhead line C. The supports are designated by reference numeral B and generally comprise a frame that is cantilevered with respect to a support pole ST to which the weight-bearing cable or the contact line P is attached.In this case, the system 1 additionally comprises one or more electromagnetic wave detection devices 2, which in turn are preferably arranged on the roof of a rail vehicle, advantageously one or more image acquisition devices 4, which are configured to frame the corresponding track infrastructure (the support B) and to provide, by means of image processing algorithms known per se, an indication of the geometry of the support B itself and - in combination with the data acquired by means of the device 2 - an indication of its position in relation to the plane of the rails (height in the direction Z in relation to the axis Y / plane XY, wherein the axis Z is perpendicular to the plane XY).

[0015] The combination of device 2 with the image acquisition devices 4 is important insofar as device 2 provides intrinsically calibrated geometric dimensions, whereas the dimensions in the image vary depending on the distance, the optics, and the viewing angle. With reference to Fig. 10 and Fig. In a further embodiment of the system 1, it is possible to provide a radar 2 that can be installed on one side of the rail vehicle V and is configured to detect the position of the support poles ST. In this case as well, the electromagnetic wave detection device 2 is preferably a phased-array radar configured to scan the rail infrastructure 30 within a measuring range defined by the angle β, which can vary depending on the control of the radar 2's transmit / receive antennas.

[0016] With reference to Fig. 12 and Fig. In a further embodiment of the system 1, it is possible to provide a radar 2 that can be installed on the loading platform of a railway wagon or tracked vehicle, even if driven by a person or pushed or pulled by people on the ground, and is configured to detect the position of the wires (weight-bearing cable P or contact wires L) of the overhead line C. The reference parameter in this case is the distance h, measured in the (vertical) direction Z with respect to the plane (parallel to the plane XY) tangential to the loading platform of the wagon or tracked vehicle, which corresponds to the distance of the system 1 from the plane of the loading platform itself. The distance h is a function of the desired lateral resolution (axis Y) of the instrument: the better the desired resolution, the greater the distance h.In this case, too, the electromagnetic wave detection device 2 is preferably a phased-array type radar configured to scan the rail infrastructure (overhead line L) in a measuring range defined by the angle β, which varies depending on the control of the transmitter-receiver antennas of the radar 2 itself.

[0017] According to an advantageous aspect of the invention, the hardware of system 1 is standardized for all applications described herein; that is, preferably, the arrangement of transmitting and receiving antennas always has the same structure, regardless of the application. The adjustment of the operating parameters is achieved by generating different signals for driving the antennas. The angle β is typically one of the parameters that is adjusted by making variations to the driving signals. For example, in the case of vehicles V consisting of low or lowered carriages, bogies, or track carriages (small distance h), it is preferable to set an angle β to smaller values ​​than in the case of a large distance h, in order to always and only explore the area of ​​interest in the transverse direction Y. With reference to Fig. 14 In yet another embodiment of the system 1, it is possible to provide a radar 2 that can be installed under the loading platform of any rail vehicle and is configured to detect a profile BLP of the track ballast BL. In this case, the ballast forms the track infrastructure that is investigated by the system 1, and the profile BLP corresponds to an envelope of the positions of each point of the ballast with respect to the reference frame of each electromagnetic wave detection device 2.

[0018] In a preferred embodiment, the system 1 comprises three radars 2, one of which is positioned centrally and the others on either side of the vehicle to cover the entire cross-section of the ballast BL. Generally, the number of radars 2 is appropriate to the cross-section of the ballast and the measuring angle (or measuring angle range) β of each radar 2. For example, in Fig. 14 The three radars 2 are represented such that they have measurement angles β (center radar), β' (left radar), β'' (right radar). Depending on the requirements, the three angle values ​​can be identical to each other, specialized according to area (for example, β ≠ β' = β''), or all different from each other (β ≠ β' ≠ β'').

[0019] The measurement of the BLP profile of the ballast BL, while the rail vehicle V is moving, yields a sequence of cross-sectional profiles (i.e. profiles transverse in relation to the railway track, i.e. in relation to the direction of movement) that correspond either to a section of the rail between two successive sleepers or to a section of the rail spanning a sleeper.

[0020] The profile recorded in the latter section provides a reference for processing the profile recorded in the space between successive sleepers: In particular, the control unit C can be programmed to recognize the BLP profiles recorded in spaces between successive sleepers (i.e., representing only the ballast) and those obtained when a sleeper is present, in order to compare the former with the latter and to determine the deviations of the BLP ballast-only profile with respect to the BLP profiles recorded when the sleepers are present (which for the most part represent the sleepers themselves).Therefore, a deviation indicator can be calculated for the profile recorded when only the ballast is present, in relation to the profile recorded when only the sleepers are present. An error can be recorded if the deviation indicator is excessive in a positive direction (ballast at the sleepers: risk of damage to the underside of rolling stock due to stones being thrown up) or in a negative direction (ballast too far below the sleepers: risk of gradient shifting). This also applies to the embodiment of... Fig.14. The system 1 can be equipped with one or more image acquisition devices that cooperate with the one or more electromagnetic wave detection devices (e.g., radars) 2. In each of the embodiments described herein, the system 1 enables the implementation of a method for detecting track infrastructure, comprising: - installing the detection system 1 on a railway vehicle V, whatever its type (locomotive, wagon, car, track trolley, or handcar); - moving the railway vehicle along a railway track on which the track infrastructure to be detected is located; - activating the at least one electromagnetic wave detection device (e.g., radars).of the radar 2), to direct electromagnetic waves towards the track infrastructure to be detected; and - processing, by means of the control unit, the electromagnetic waves reflected by the track infrastructure, and determining a position of the track infrastructure with respect to a preset reference system (for example, with respect to a local reference system of the device 2, or again with respect to a reference system which in turn is defined with respect to one or more local reference systems of the device 2 or devices 2).

[0021] The person skilled in the art will recognize that the system 1 according to the invention is free from all the contamination problems that affect optical devices of a known type, while retaining all their advantages. The electromagnetic wave detection devices 2 are, in fact, essentially insensitive to contamination—whether mounted on the roof, sides, or under the loading platform of the vehicle—and can also be installed on the rail vehicle as required. Furthermore, the electromagnetic wave detection devices 2 do not require contact between them and the overhead line C, so they can be used to measure any section of the track, even if it is not involved in supplying power to the rail vehicle V.

[0022] Of course, the details of the construction and embodiments may vary considerably from what has been described and illustrated herein, without deviating from the scope of the present invention as defined in the attached claims. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] CN 107 678 036 A

[0001] WO 97 / 31810 A1

[0001] US 2018 / 329052 A1

[0001]

Claims

[1] Detection system (1) for track infrastructure (C, P, L, ST, B, BL) of a railway line, comprising: - at least one electromagnetic wave detection device (2, 2A, 2B) comprising at least one transmit-receive antenna, wherein the electromagnetic wave detection device (2, 2A, 2B) is configured to emit electromagnetic waves towards a track infrastructure (C, P, L, ST, B, BL) by means of the at least one transmit-receive antenna and to receive electromagnetic waves reflected from the track infrastructure (C, P, L, ST, B, BL); and - a control unit configured to process the electromagnetic waves reflected by the track infrastructure (C, P, L, ST, B, BL) and to determine a position of the track infrastructure (C, P, L, ST, B, BL) relative to a preset reference system, wherein the at least one electromagnetic wave detection device (2, 2A, 2B) is configured for installation on board a rail vehicle (V), and wherein the at least one electromagnetic wave detection device (2, 2A, 2B) comprises a phased array radar incorporating a plurality of transmit-receive antennas. [2] Detection system (1) according to claim 1, wherein the at least one electromagnetic wave detection device (2A, 2B) comprises a pair of phased array radars having incidence axes. [3] Detection system (1) according to claim 2, wherein the transmit-receiver antennas of a first phased-array radar (2A) of the pair are supplied with a different frequency compared to the transmit-receiver antennas of a second phased-array radar (2B) of the pair. [4] Detection system (1) according to any of the preceding claims, further comprising at least one image acquisition device (3) configured to cooperate with the at least one electromagnetic wave detection device (2, 2A, 2B) for the acquisition of image data relating to the track infrastructure (C, P, L, ST, B, BL) upon which the electromagnetic waves emitted by the at least one electromagnetic wave detection device (2, 2A, 2B) meet. [5] Rail vehicle (V) comprising a detection system (1) according to any one of claims 1 to 4. [6] Rail vehicle (V) according to claim 1, wherein the detection system is installed in combination or alternatively: - on the roof of the vehicle, - along one side of the vehicle's bodywork, - under the loading platform of the vehicle.

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