Sensor device for sensing strains on a linear infrastructure component, in particular a track rail, measuring arrangement, method and application apparatus

Abstract

The invention relates to a sensor device (3) for sensing strains on a linear infrastructure component (12), in particular a track rail, comprising: a first sensor unit (16, 16'), which has a first support (28) and at least one strain sensor for sensing a strain at the first measuring point (19), said at least one strain sensor being held by the first support (28); a second sensor unit (17), which has a second support (29) and at least one strain sensor for sensing a strain at the second measuring point (20), said at least one strain sensor being held on the second support (29); a coupling means (18), which is connected to the first support (28) and the second support (29), for determining a measurement distance (d) between the first measuring point (19) and the second measuring point (20) along a longitudinal direction (21) of the linear infrastructure component (12). The invention also relates to a measuring arrangement (19) having the sensor device (3), to a method and to an application apparatus for applying the sensor device (3).

Description

[0001] Sensor device for detecting strains on a linear infrastructure component, in particular a track rail, measuring arrangement, method and application device

[0002] The content of the German patent application DE 102024210287.3 is incorporated herein by reference.

[0003] The invention relates to a sensor device for detecting strains in a linear infrastructure component, in particular a railway track. The invention further relates to a measuring arrangement with such a sensor device. The invention also relates to a method and an application device for applying such a sensor device.

[0004] Fiber optic strain sensors for detecting the strain of a railway track are known from WO 2015 / 110361 A2. The strain is detected in the area of ​​a sleeper bay between two adjacent track sleepers. The strain sensors are individually connected to the track and each is separately connected to an evaluation unit. Disadvantages include the fact that mounting the strain sensors on the track is complex and prone to errors, the equipment is expensive, and the information gained, and therefore the range of applications, is limited.

[0005] It is an object of the invention to provide an improved sensor device for detecting strains on a linear infrastructure component, in particular a track rail, which is particularly economical and reliable to manufacture and assemble, robust in operation and versatile in its application.

[0006] This problem is solved by a sensor device with the features of claim 1. It has been recognized that a sensor device for detecting strains on a linear infrastructure component, in particular on a railway track, comprising a first sensor unit and a second sensor unit, can include a coupling means for defining a measuring distance between the respective measuring points of the sensor units in order to be particularly economical and reliable to manufacture and assemble, robust in operation, and to have a broader range of applications. The design of the sensor device with the first support, the second support, and the coupling means ensures that the relative position and / or orientation of two or more strain sensors of the different sensor units can be precisely defined, in particular, already determined during the manufacture of the sensor device.The multiple strain sensors can be attached to the linear infrastructure component with reduced effort, particularly in a single positioning and alignment step. This eliminates the need for each individual strain sensor to be precisely positioned and aligned on the linear infrastructure component. In particular, potential sources of error associated with individual mounting are eliminated. Due to the simplified installation of the sensor assembly, its partial or fully automated attachment to the infrastructure component is possible. The positioning and alignment of the multiple strain sensors relative to each other can be carried out during the manufacturing of the sensor assembly under controlled environmental conditions, thus ensuring exceptional precision.The reduced assembly effort makes it possible, especially with the same effort, to equip the linear infrastructure component with a larger number of sensor units, particularly strain sensors, thereby increasing the information gain and expanding the range of applications.

[0007] The linear infrastructure component can generally be an elongated object. Preferably, the linear infrastructure component is a railway track.Alternatively, the linear object can be a pipe, a cable, in particular a suspension cable of a bridge or cable car, an electrical line, in particular a power line, an engineering structure, such as a bridge, a supporting structure, a fluid line, for example a fuel pipeline, a water line, in particular a drinking water line, a hot water line, a geothermal line and / or a gas line, an above-ground and / or underground facility, a wind turbine tower, a transport route, in particular a road, a bridge, a track, a high-speed transport route, in particular a vacuum transport tube, and / or any other elongated object whose elongation at at least two measuring points along the longitudinal direction of the linear infrastructure component is potentially of interest.

[0008] The at least one strain sensor is preferably connected to the respective carrier by a material bond, a positive fit, and / or a force-fit. For example, the at least one strain sensor can be encased and / or overmolded by the carrier material. A measuring contact surface is understood to be that surface of the sensor device, in particular the sensor unit, which is intended for contact with the linear infrastructure component and / or via which the sensor unit is attached to the linear infrastructure component or receives the strain to be detected.

[0009] The at least one strain sensor can have a distance to the measuring contact surface of a maximum of 2 mm, in particular a maximum of 1 mm, in particular a maximum of 0.5 mm, in particular a maximum of 0.2 mm, in particular a maximum of 0.1 mm, in particular a maximum of 0.05 mm, and / or a minimum of 0.01 mm. A surface of the at least one strain sensor can form the measuring contact surface, at least partially. The at least one strain sensor can be completely and / or partially, but not completely, enclosed by the respective carrier, in particular not at the measuring contact surface.

[0010] Preferably, the measuring point can define the cutting plane or measuring plane at which the strain in the linear infrastructure component, particularly in the track rail, is recorded. The cutting plane is preferably oriented perpendicular to the longitudinal direction of the linear infrastructure component. The measuring point can define the position along the longitudinal direction of the linear infrastructure component at which the shear forces of the linear infrastructure component are determined.

[0011] The respective measuring point is preferably the position at which the strain of the linear infrastructure component is determined by means of the respective sensor unit, in particular the at least one strain sensor. With a single strain sensor, the strain is preferably detected directly at the measuring point. With multiple strain sensors, these can be arranged at a distance, preferably a short distance, from the measuring point or grouped around it. Alternatively, the multiple strain sensors can overlap each other and the measuring point in a top view of the measuring point, in particular the measuring contact surface. In other words, the multiple strain sensors for detecting the strain at the same measuring point can be arranged in the measuring contact surface and / or perpendicular to it.The distance between the at least one strain sensor, in particular all strain sensors, and the associated measuring point is preferably a maximum of 25 mm, in particular a maximum of 10 mm, in particular a maximum of 5 mm, in particular a maximum of 2 mm, in particular a maximum of 1 mm, in particular a maximum of 0.5 mm, in particular a maximum of 0.1 mm, in particular a maximum of 0.01 mm, in particular a maximum of 0.001 mm, and / or a minimum of 0.001 mm.

[0012] The coupling means preferably, and in particular together with the first support and / or the second support, defines the measuring distance between the first sensor unit and the second sensor unit, in particular between the first and second measuring points. The measuring distance is determined in particular in the longitudinal direction of the linear infrastructure component. A straight line between the first and second measuring points is preferably oriented substantially parallel to the longitudinal direction. This preferably also includes angular deviations of a maximum of 10°, in particular a maximum of 5°, in particular a maximum of 2°, in particular a maximum of 1°, in particular a maximum of 0.5°, in particular a maximum of 0.1°, in particular a maximum of 0.01°, for parallel orientation.

[0013] Preferably, the coupling means, particularly together with the first and / or the second carrier, is configured to establish a translationally and / or rotationally rigid connection between the first and the second sensor unit, in particular between the two carriers and / or the first and second measuring points. A connection between the coupling means and the respective sensor unit, in particular the respective carrier, and / or the coupling means itself can be translationally and / or rotationally rigid. This ensures that the measuring points are defined with particular precision relative to each other.

[0014] The coupling element and the first and / or second support can be multi-part and / or single-part. For example, the coupling element and the first and / or second support can be materially bonded, in particular by adhesive bonding and / or welding. The coupling element and the first and / or second support can be manufactured in one piece, in particular by casting and / or injection molding. Alternatively, the coupling element can be designed as a separate component and mounted to the first and / or second support, in particular by material bonding, friction bonding, and / or form-fitting. The first and / or second support and / or the coupling element can be made of a plastic material, in particular a thermoset material and / or an elastic material, for example, polyethylene and / or polypropylene and / or polyurethane, and / or a metallic material, in particular aluminum.

[0015] The coupling means can include at least one signal line running between the first and second sensor units, in particular their strain sensors, and in particular at least one measurement signal line, especially an electrical and / or a fiber optic signal line. This allows for a particularly economical and robust connection of the measurement signal to the strain sensors, especially when bundled for at least two measuring points.

[0016] The first strain sensor and / or the second strain sensor, in particular all strain sensors, can be electrical strain sensors, especially film sensors, and / or optical strain sensors. Such strain sensors are particularly robust and deliver precise measurement results.

[0017] The sensor device, in particular the first and second sensor units, can be bonded to the linear infrastructure component, in particular by adhesive bonding. Specifically, an adhesive layer can be formed between the linear infrastructure component and the sensor device. The adhesive layer can have a thickness of a maximum of 2 mm, in particular a maximum of 1 mm, in particular a maximum of 0.5 mm, in particular a maximum of 0.1 mm, in particular a maximum of 0.05 mm, and / or a minimum of 0.001 mm. This allows for particularly precise detection of strains.

[0018] According to one aspect, the sensor device can be designed for application on a rail web of the track. For this purpose, the sensor device can have dimensions that ensure suitability for mounting on a rail web. In particular, the height of the sensor device can correspond to the height of the track, especially the rail web, and / or lie within a range of 1 cm to 30 cm, specifically 2 cm to 20 cm, specifically 4 cm to 16 cm, specifically 6 cm to 12 cm. The respective sensor unit can have a corresponding height. In particular, the measuring contact surface of the sensor device, especially the respective sensor unit, can have a corresponding height.The thickness of the sensor device, in particular of the respective sensor unit, especially perpendicular to the measuring contact surface, is preferably in a range of 0.01 cm to 10 cm, in particular from 0.1 cm to 5 cm, in particular from 0.2 cm to 4 cm, in particular from 0.5 cm to 3 cm.

[0019] According to another aspect, the measuring distance between the first and second measuring points can be in a range of 5 cm to 200 cm, in particular from 10 cm to 120 cm, in particular from 15 cm to 60 cm, and in particular from 20 cm to 40 cm. This advantageously allows the two sensor units to be mounted along the longitudinal direction within the same sleeper bay or between two adjacent track sleepers on the track rail.

[0020] According to another aspect, the coupling element and / or the first support and / or the second support can be designed to be flexible. This advantageously ensures that the respective measuring contact surface can be molded particularly precisely to the surface of the linear infrastructure component. In particular, a substantially constant adhesive layer thickness between the sensor device and the linear infrastructure component can be guaranteed. The measurement results are therefore particularly precise. Preferably, the coupling element and / or the first and / or the second support comprise an elastic material, in particular an elastic plastic, for example polyurethane and / or silicone and / or EPDM, and / or a rubber, in particular NBR, and in particular, they consist of such a material.

[0021] In general, the coupling means and / or the first and / or second support can be designed to be flexible and / or rigid and / or flexurally rigid.

[0022] The hardness of the material of the coupling means and / or of the first and / or the second support is preferably in a range of 10 Shore A to 100 Shore A, in particular of

[0023] 20 ShoreA to 80 ShoreA, especially from 30 ShoreA to 60 ShoreA.

[0024] According to another aspect, the at least one strain sensor can be a fiber optic strain sensor; in particular, all strain sensors can be fiber optic strain sensors. The fiber optic strain sensor can have an optical waveguide, in particular an optical fiber, especially a glass fiber. The at least one strain sensor, in particular the first and / or the second strain sensor, can be a fiber Bragg grating sensor. Such sensors are particularly precise and robust in operation and are especially suitable for long transmission distances of the measurement signal.

[0025] According to a further aspect, at least one strain sensor of the first sensor unit and at least one strain sensor of the second sensor unit can be connected, and in particular designed, by the same optical fiber. In particular, the fiber bracing of both strain sensors can be located in the same optical fiber. Preferably, at least three, in particular at least five, in particular at least ten, and in particular all, strain sensors of one sensor unit and / or both sensor units and / or the sensor device are connected by the same optical fiber. This significantly reduces the effort associated with connecting the strain sensors. Securing a corresponding signal connection, especially when used on track rails, is also considerably simplified.

[0026] The sensor device can have several measurement signal lines, in particular optical fibers, which are designed separately from each other or are intended for separate connection to an evaluation device.

[0027] According to another aspect, the coupling medium can carry at least one, and in particular exactly one or more, measurement signal lines for transmitting a measurement signal between the first sensor unit and the second sensor unit. The at least one measurement signal line can, for example, be embedded in the material of the coupling medium, and in particular be completely surrounded by it. This makes the sensor device particularly robust in operation and easy to handle.

[0028] According to a further aspect, the coupling means can carry at least two separately designed optical fibers, in particular measurement signal lines, and / or data signal lines. The data signal line preferably, in particular additionally or exclusively, transmits signals other than the measurement signals, for example, communication signals. The coupling means can also carry several measurement signal lines. This allows the number of strain sensors incorporated into the single-piece sensor device to be increased. The coupling means preferably carries at least two, in particular at least five, and / or a maximum of twenty, in particular a maximum of ten, separate optical fibers.

[0029] According to one aspect, the first sensor unit can have at least two strain sensors for detecting strain at the first measuring point. The second sensor unit can have at least two strain sensors for detecting strain at the second measuring point. Each sensor unit can, in particular, have at least three, in particular at least four, in particular five, and / or a maximum of ten strain sensors, which are specifically designed to detect strain at the measuring point of the respective sensor unit.

[0030] According to a further aspect, the measuring direction of the at least one strain sensor can be oriented obliquely to the longitudinal direction of the linear infrastructure component, in particular at an angle to the longitudinal direction in a range of 20° to 70°, in particular from 30° to 60°, in particular from 40° to 50°, and in particular from 45°. The aforementioned angular ranges can alternatively or additionally exist with respect to a straight line between the first measuring point and the second measuring point. This allows for the determination of shear strain, particularly when the respective strain sensor is arranged on the rail web.

[0031] According to a further aspect, the measuring direction of at least one strain sensor of the first and the second sensor unit can be oriented obliquely to the longitudinal direction and / or obliquely to an orthogonal direction to the longitudinal direction of the linear infrastructure component, in particular obliquely to the vertical direction. Specifically, two strain sensors of each sensor unit can have such an orientation.

[0032] According to a further aspect, at least one, in particular exactly one, strain sensor of the sensor device, in particular one of the sensor units, in particular each sensor unit, can have a measuring direction aligned parallel to the longitudinal direction of the linear infrastructure component. This allows longitudinal strains to be detected, in particular a longitudinal strain of the track rail. According to a further aspect, at least one, in particular at least two, in particular exactly two, strain sensors of the sensor device, in particular at least one of the sensor units, in particular each sensor unit, can have a measuring direction aligned perpendicular to the longitudinal direction of the linear infrastructure component, in particular vertically.This allows for the detection of transverse strains, particularly transverse strains of the track rail, and / or the precise determination of the neutral axis's position, and / or the particularly precise determination of shear strain based on the transverse strains. Preferably, transverse strains above and / or below the neutral axis and / or the measuring point are detected, particularly at a distance from it in a range of 1 mm to 100 mm, particularly from 5 mm to 70 mm, and particularly from 10 mm to 40 mm.

[0033] According to a further aspect, the sensor device can have at least one temperature sensor, in particular on the first and / or the second carrier and / or on the coupling means. The temperature sensor can be a fiber optic temperature sensor, in particular a fiber Bragg grating sensor, and / or another fiber optic temperature sensor, for example a distributed temperature sensing (DTS) sensor, in particular for temperature determination based on a fiber optic Raman backscattering method, and / or an electrical sensor, in particular a film sensor.

[0034] The at least one temperature sensor preferably ensures that temperature influences, in particular strains, especially of the sensor and / or the linear infrastructure component, due to temperature influences, can be determined and / or compensated for or mathematically eliminated, especially by means of the evaluation unit. For example, the at least one temperature sensor or the associated evaluation unit can be configured to determine and / or compensate for the temperature-dependent measurement behavior of at least one strain sensor and / or the dependence of the measurement signal of at least one strain sensor on the thermal expansion of the linear infrastructure component, especially the track rail.

[0035] According to another aspect, the at least one temperature sensor and at least one, in particular at least two, of the strain sensors, in particular all strain sensors of the same sensor unit, in particular of the same sensor device, can be formed by the same light-conducting fiber.

[0036] According to a further aspect, the sensor device, in particular the first sensor unit and / or the second sensor unit, and especially the first support and / or the second support, comprises a positioning stop for reversibly and positively fixing the position and orientation of the sensor device relative to an application device and / or to the linear infrastructure component, in particular the track rail. The positioning stop can have one or more stop elements, in particular made of a rigid material, for example, a rigid plastic and / or metal. The stop elements can be arranged circumferentially on at least one of the sensor units or on the coupling means.

[0037] According to one aspect, the sensor device can have at least one, in particular at least two, in particular at least five, in particular at least 10, in particular at least 20, and / or a maximum of 500, in particular a maximum of 100, in particular a maximum of 50, further sensor units, which are in particular structurally and / or signal-transmittingly connected to one another. The aspect of fixing several sensor units in a predetermined position and / or orientation relative to each other via a coupling means can thereby be extended to further sensor units. The at least one further sensor unit preferably has a further carrier and at least one strain sensor, received by the further carrier, for detecting a strain at a further measuring point.

[0038] Preferably, the sensor device, in particular each additional sensor unit, comprises a further coupling means for connecting the additional sensor unit to an adjacent sensor unit, in particular an adjacent additional sensor unit and / or the first sensor unit and / or the second sensor unit. The at least one additional coupling means can be configured to define a measuring distance between the additional measuring point and the adjacent measuring point or the measuring point of the adjacent sensor unit, in particular in the longitudinal direction of the linear infrastructure component. Alternatively, the additional coupling means can be flexible, in particular flexible and / or elastic, in particular to allow the additional measuring point to shift relative to the adjacent measuring point.For example, the additional coupling means can be cable-shaped, especially ribbon-shaped, to ensure longitudinal flexibility by forming a loop.

[0039] Preferably, two of the sensor units are connected by a coupling means that defines the measuring distance between their measuring points, particularly in the longitudinal direction of the linear infrastructure component. Two such sensor units are also referred to as a sensor unit pair. A shape-flexible, and in particular length-flexible, coupling means can be arranged between adjacent sensor unit pairs.

[0040] According to one aspect, at least two of the measuring units and / or measuring points of the sensor device can be spaced at least 0.6 m apart, in particular at least 1 m apart, in particular at least 2 m apart, in particular at least 4 m apart, in particular at least 10 m apart, and / or at most 250 m apart, in particular at most 100 m apart. In particular, the total length of the sensor device can be within the aforementioned range. This allows the sensor device to detect the stress on the linear infrastructure component over a long length, in particular across several threshold sections. Preferably, at least one sensor unit, in particular two sensor units, is provided per threshold section. A measuring signal line, in particular an optical fiber of the sensor device, preferably extends over the entire length between the measuring points, in particular over the entire length of the sensor device.

[0041] According to another aspect, the sensor device can be designed to be coiled and / or foldable. In particular, the sensor device can be wound onto a reel, especially for transport to the linear infrastructure component. This significantly simplifies the handling of the sensor device, especially before assembly of the linear infrastructure component.

[0042] A further object of the invention is to provide an improved measuring arrangement that is particularly economical and reliable to manufacture, as well as robust and flexible in use. This object is achieved by a measuring arrangement comprising a linear infrastructure component, in particular a track rail, and a sensor device bonded to it according to the preceding description, wherein the first and second measuring points are arranged on the linear infrastructure component at the measuring distance defined by the coupling means. The measuring arrangement can be further developed with at least one of the features described above in connection with the sensor device. The advantages of the measuring arrangement preferably correspond to the advantages of the sensor device.

[0043] The material-bonded connection between the linear infrastructure component and the sensor device is preferably achieved by welding and / or bonding, in particular by means of a cyanoacrylate adhesive and / or an epoxy adhesive.

[0044] An adhesive layer can be continuous or interrupted between the first and second sensor units, particularly for the first and second sensor units separately. Preferably, the pairs of sensor units are attached separately, especially sequentially, to the linear infrastructure component, particularly by gluing or welding.

[0045] According to one aspect, the first and second measuring points are arranged on a rail web of the track rail, in particular attached, in particular glued.

[0046] At least one, and in particular exactly one, strain sensor, particularly per sensor unit, can be arranged on the rail foot, in particular on the top, a side surface and / or the underside of the rail foot and / or on a rail head, in particular on the underside and / or a side surface of the rail head. A strain sensor arranged longitudinally or perpendicularly to the longitudinal direction of the track rail can be arranged on the rail foot and / or on the rail head.

[0047] The first and second measuring points are preferably located in the neutral axis of the track rail. The neutral axis is defined by the fact that no longitudinal forces occur there during pure bending, particularly around a horizontal transverse direction. Measuring the neutral axis ensures a particularly precise determination of the stress on the infrastructure component, especially shear strains.

[0048] According to a further aspect, the measuring arrangement can include a covering material which, together with the linear infrastructure component, in particular the track rail, encloses or seals the first and / or the second sensor unit in a liquid-tight, in particular moisture-tight, manner. The covering material can comprise, and in particular consist of, a plastic material, for example polyurethane and / or bitumen. The covering material can be rigid or elastic. The covering material can include a housing, in particular comprising a plastic material and / or a metallic material.

[0049] According to another aspect, the first and second measuring points can be arranged longitudinally between two adjacent track sleepers, particularly in a so-called sleeper bay. By determining the strains of the track rail at at least two measuring points along the longitudinal direction, the influences of the supports, especially the ballast bed, can be identified and / or compensated for. The strains can be determined with particular precision and allow for particularly precise conclusions to be drawn about the actual stress on the track rail.

[0050] The invention also relates to a measuring system comprising a sensor device, in particular a measuring arrangement, according to the preceding description, and an evaluation device for evaluating measurement signals from the at least two strain sensors. The evaluation device preferably comprises at least one processor for processing digital data. The evaluation device can have at least one, in particular three, in particular at least five, in particular at least 10, and / or a maximum of 50 measurement signal line inputs. The measuring system can be further developed with at least one of the features described above in connection with the sensor device and / or the measuring arrangement.

[0051] A further object of the invention is to provide an improved method for applying a sensor device to a linear infrastructure component, in particular a railway track, which is especially economical and robust in its design. This object is achieved by a method for applying a sensor device to a linear infrastructure component, in particular a railway track, comprising the steps of: providing a sensor device, in particular according to the preceding description, and attaching the sensor device to the linear infrastructure component such that the two measuring points on the linear infrastructure component are arranged at the measuring distance defined by the coupling means. The method can be further developed with at least one of the features described above in connection with the sensor device and / or the measuring arrangement and / or the measuring system.The advantages of the method preferably correspond to the advantages of the sensor device and / or the measuring arrangement and / or the measuring system.

[0052] The method preferably comprises cleaning and / or grinding and / or sandblasting and / or laser blasting and / or water jetting and / or brushing and / or plasma treatment of the infrastructure component and / or unwinding the sensor device, in particular from a reel, and / or unfolding the sensor device and / or applying adhesive, in particular to the sensor device and / or the infrastructure component, and / or feeding the sensor device to the infrastructure component, in particular into contact with the infrastructure component, and / or pressing the sensor device onto the infrastructure component and / or curing the adhesive and / or covering at least one, in particular all, of the sensor units, in particular with the covering agent, and / or laying and / or securing at least one measuring signal line and / or connecting the measuring signal line to the evaluation device.

[0053] According to one aspect, the positioning and / or alignment of the sensor device with respect to the infrastructure component can be achieved using an application device, which preferably interacts positively with a positioning stop of the sensor device. The application device can preferably press the sensor device against the infrastructure component. This makes installation particularly time-efficient, economical, and reliable. According to another aspect, the sensor device is calibrated by running a rail vehicle, in particular a calibration vehicle, with a known weight along the track rail. This allows a defined load to be applied to the track rail. Based on this, the transfer function, in particular the calibration curve, of the respective strain sensor attached to the track rail can be determined.Preferably, the track is traversed by rail vehicles of different, known weights. This allows the transfer function of the strain sensors to be determined with particular precision, especially for different points on the transfer function.

[0054] A further object of the invention is to provide an improved application device for applying a sensor device to a linear infrastructure component, in particular a track rail, which in particular ensures a particularly economical and reliable mounting of the sensor device on the infrastructure component.

[0055] This problem is solved by an application device for applying a sensor device to a linear infrastructure component, in particular a track rail, comprising a fastening means for reversibly and positively fixing the position and orientation of the application device relative to the linear infrastructure component and a counter-positioning stop for reversibly and positively fixing the position and orientation of the sensor device, in particular at least one sensor unit, relative to the application device. The application device can be further developed with at least one of the features described above in connection with the sensor device and / or the measuring arrangement and / or the measuring system and / or the method.The advantages of the application device preferably correspond to the advantages of the sensor device and / or the measuring arrangement and / or the measuring system and / or the method.

[0056] The fastening device can be designed for a positive-locking and / or force-locking connection to the infrastructure component, in particular the track rail. The fastening device can have two pivotally connected fastening elements. The application device can have a pressure plunger for exerting a pressing force, in particular an adjustable force, on the at least one sensor unit. For example, the pressure plunger can be connected to the fastening device via a clamping device or pressure force device, in particular a thread. The counter-positioning stop can be designed to complement the positioning stop of the sensor device.

[0057] The application device can have at least one magnet, preferably a permanent magnet, or alternatively an electromagnet, for attaching the sensor device, in particular at least one, especially the first and second sensor units, to the linear infrastructure component, especially the track rail, particularly for exerting the contact force on the sensor units. By means of the magnetic force acting between the linear infrastructure component and the application device, the sensor device arranged between them, in particular the at least one sensor unit, can be pressed against the linear infrastructure component. The magnet can be a component of a pressure piston.

[0058] Preferably, the application device comprises a layer of an elastic material, particularly on the pressure plunger, through which the contact force is transmitted to the sensor device, especially the at least one sensor unit. This allows unevenness in the contact area between the application device and the sensor device to be compensated for.

[0059] The application device can have at least one clamping device for exerting the contact force, in particular via the pressure plunger, on which at least one sensor unit can be mounted.

[0060] The fastening device can be designed such that the counterforce or reaction force corresponding to the clamping force clamps the fastening device, in particular the application device, to the linear infrastructure component or clamps it into a locking position in which the fastening device is immovably fixed to the linear infrastructure component. When the clamping force is released, the fastening device can be removed from the linear infrastructure component, in particular manually. The fastening device can, for example, have two fastening clamps and a joint that pivotally connects the fastening clamps to each other. The reaction force can clamp the joint to an angular limit and simultaneously clamp the fastening clamps against the linear infrastructure component to achieve the immovable fixation.

[0061] The invention also relates to a method for operating a measuring system, in particular according to the preceding description, comprising the steps of: capturing measurement signals by means of the sensor device, in particular on the track rail; determining, on the basis of the measurement signals, at least one piece of information from the group comprising a property of the rail vehicle, in particular its length, weight, number of wagons, number of axles, condition, in particular wheel concentricity, running quality, in particular derailment tendency, in particular derailment coefficient, in particular Y / Q value (=wheel guiding force / wheel contact force or...).horizontal / vertical track shear force), lateral acceleration, bogie integrity and / or weight distribution, and / or a property of the track, in particular longitudinal elongation and / or curvature, in particular a local, especially lateral and / or vertical, displacement from a nominal arrangement, the compaction state of the track ballast and / or the structural integrity of the track rail, in particular cracking, and / or the integrity of the rail fastening and / or the temperature of the track rail and / or at least one sensor and / or the environment, and / or a property of rail traffic, for example the position of a rail vehicle and / or the number and / or time of passing rail vehicles.

[0062] Further features, advantages, and details of the invention will become apparent from the following description of several exemplary embodiments with reference to the figures. The figures show:

[0063] Fig. 1 shows a schematic representation of a measuring arrangement with a linear infrastructure component in the form of a track rail and a sensor device attached to it for detecting strains at several measuring points.

[0064] Fig. 2 is a schematic detail representation of the measuring arrangement in Fig. 1, wherein two measuring units are held at a measuring distance from each other by a coupling means; Fig. 3 is a sectional view of the measuring arrangement along the section line III-III in Fig.

[0065] 2, wherein a sensor device is attached to each side of a rail web of the track rail,

[0066] Fig. 4 shows a rear view of one of the sensor units of the measuring arrangement in Fig. 1, wherein strain sensors of the sensor unit are designed as fiber optic strain sensors.

[0067] Figs. 5A-5F schematic representations of sensor units according to further embodiments, or

[0068] Figs. 6A-6F schematic sectional views through measuring arrangements according to further embodiments.

[0069] Figures 1 to 4 describe a first embodiment of a measuring arrangement 1. The measuring arrangement 1 comprises a linear infrastructure component 2, in particular a track rail, and a sensor device 3 for detecting strains, which is bonded to it.

[0070] The sensor device 3 is preferably in signal communication with an evaluation device 5. In particular, the sensor device 3 and the evaluation device 5 are components of a measuring system 6. The evaluation device 5 is preferably configured to process the sensor signals of the sensor device 3, in particular to evaluate the combined sensor signals of several sensors, especially to determine information about the stress and / or the load on the track rail 2 and / or the condition of a rail vehicle 9 traveling on it and / or the track 10. The evaluation device 5 can have a wired signal connection to the sensor device 3.

[0071] The evaluation unit 5 can be in signal communication with a central processing unit 7, in particular a control center and / or a signal box 8, especially for transmitting the measurement signals or information derived therefrom. The signal connection can be wired and / or wireless, in particular as a radio connection, especially as a mobile communication connection. The evaluation of the measurement signals can alternatively or additionally be carried out by means of the central processing unit 7.

[0072] The track 10 comprises track sleepers 11 arranged on a track bed 12, in particular a ballast bed, and two track rails 2 fastened to the track sleepers 11. Each track rail 2 comprises a rail head 13, a rail web 14 and a rail foot 15.

[0073] The sensor device 3 comprises a first sensor unit 16, a second sensor unit 17, and a coupling means 18. Each sensor unit 16, 17 is designed to detect strain at a measuring point 19, 20. The respective measuring points 19, 20 are located on the rail web 14. The coupling means 18 connects the first and second sensor units 16, 17 such that the measuring points 19, 20 are arranged at a defined measuring distance d from each other.

[0074] The measuring distance d is preferably measured along a longitudinal direction 21 of the track 10, in particular the track rail 2. A straight line between the two measuring points 19, 20 parallel to the longitudinal direction 21 is particularly preferred.

[0075] The two measuring units 16, 17, and in particular the coupling means 18, are arranged, in particular along the longitudinal direction 21, between two adjacent track sleepers 11, in particular in the same sleeper bay 22. The distance x between two adjacent track sleepers 11 is preferably in a range of 0.4 m to 1 m, in particular from 0.5 m to 0.8 m, and in particular is 0.6 m.

[0076] The measuring distance d is preferably in a range of 0.1 m to 0.6 m, particularly from 0.2 m to 0.4 m, and in particular can be 0.3 m. A ratio between the distance x of adjacent track sleepers 11 and the measuring distance d can be in a range of 1.2:1 to 5:1, particularly from 1.5:1 to 4:1, and in particular from 1.8:1 to 3:1.

[0077] The sensor device 3 can have at least one further sensor unit 23 for detecting strains at at least one further measuring point 24. The further sensor unit 23 can be connected to the respective adjacent sensor unit 16, 17, 23 via a further coupling means 25. The further coupling means 25 can be configured to connect the further sensor unit 23 to an adjacent sensor unit 16, 17, 23, in particular to connect it for signal transmission and / or structurally, in particular such that the further measuring point 24 is arranged at a defined further measuring distance d to an adjacent measuring point 19, 20, 24. The further measuring distance d can correspond to or deviate from the measuring distance d.

[0078] Each pair of sensor units 16, 17, 23 can form a sensor unit pair 26, in particular together with the coupling means 18 connecting them, especially with a coupling means 18 defining the measuring distance d. Preferably, exactly one sensor unit pair 26 is assigned to each threshold compartment 22 over which the sensor device 3 extends.

[0079] Adjacent pairs of sensor units 26 are preferably connected to each other for signal transmission, in particular to the further coupling means 25. The relative position of two adjacent pairs of sensor units 26 is preferably variable, in particular in the longitudinal direction 21 of the track rail 2. For this purpose, the further coupling means 25 can be configured to flexibly form a measuring distance d between the further measuring point 24 and an adjacent measuring point 19, 20, 24, for example by having a loop 27.

[0080] The sensor device 3 preferably comprises at least two, in particular at least four, in particular at least eight, in particular at least 10 and / or a maximum of 500, in particular a maximum of 200, in particular a maximum of 100, in particular a maximum of 50, of the sensor units 16, 17, 23.

[0081] The total length L of the sensor device 3, in particular along the track rail 2 or along a straight line, can be in a range from 1 m to 1 km, in particular from 2 m to 200 m, in particular from 5 m to 100 m, in particular from 10 m to 50 m.

[0082] Figure 2 shows one of the sensor unit pairs 26 in more detail. The coupling element 18 is rigid, in particular as a strip, for example made of a metallic material, especially aluminum. Each sensor unit 16, 17 comprises a carrier 28, 29. The respective carrier 28, 29 is flexible, in particular bendable. In particular, the respective carrier 28, 29 comprises an elastic material, in particular a plastic, for example silicone and / or polyurethane and / or a rubber material, for example NBR. Due to the flexibility of the carrier, it, and in particular the respective sensor unit 16, 17, can be attached precisely, and in particular tightly, to the surface of the track rail 2, in particular the rail web 14.

[0083] The first sensor unit 16 comprises at least one strain sensor 30, mounted on the first support 28, for detecting strain at the first measuring point 19. The second sensor unit 17 comprises at least one second strain sensor 31, mounted on the second support 29, for detecting strain at the second measuring point 20. In particular, each sensor unit 16, 17 comprises two strain sensors 30.1, 30.2, 31.1, 31.2. The strain sensors 30.1, 30.2, 31.1, 31.2 are designed as fiber optic strain sensors, in particular as fiber Bragg grating sensors. The light-conducting fiber 32, into which corresponding fiber Bragg gratings are inserted, is preferably an optical fiber.

[0084] The strain sensors 30.1, 30.2, 31.1, 31.2 are each arranged at an angle ai.i, ai.2, 012.1, 012.2 of 45° to the longitudinal direction 21 of the linear infrastructure component 2. This allows the strain sensors 30.1, 30.2, 31.1, 31.2 to precisely detect shear strains, particularly in the rail web 14.

[0085] The two measuring points 19, 20 are preferably arranged in the region of the neutral axis 33 of the track rail 2. In the neutral axis 33, the longitudinal strain of the track rail 2 is zero under pure bending stress, in particular about a horizontal transverse direction of the track.

[0086] The width b of the respective sensor units 16, 17 is preferably in the range of 1 cm to 15 cm, in particular from 2 cm to 10 cm, in particular from 4 cm to 8 cm, and in particular is 5 cm. The height h of the respective sensor unit 16, 17 can be in the range of 2 cm to 20 cm, in particular from 4 cm to 15 cm, in particular from 6 cm to 10 cm, and in particular is 8 cm. The above dimensions refer in particular to a section of the respective sensor unit 16, 17 projecting from or extending from the coupling means 18.

[0087] Figure 3 illustrates the arrangement of the sensor unit 16 on the track rail 2. The first support 28 is bonded to the track rail 2, in particular to the rail web 14, preferably by adhesive. An adhesive layer 34 preferably extends over the entire surface between the track rail 2 and the first sensor unit 16, in particular the first support 28.

[0088] The second sensor unit 17 is preferably attached to the track rail 2 in accordance with the first sensor unit 16.

[0089] The adhesive forming the adhesive layer 34 preferably comprises cyanoacrylate and / or epoxy, in particular it consists of these.

[0090] Because the first support 28 is designed to be flexible, it, and in particular the first sensor unit 16, can adapt precisely to the shape of the track rail 2, especially to a curved shape of the rail web 14. This allows the thickness of the adhesive layer 34 to be particularly uniform, thereby increasing the measurement accuracy.

[0091] According to the embodiment shown in Fig. 3, a sensor unit 16, 16', in particular symmetrically, is arranged on each side of the rail web 14. The symmetrical design of the corresponding sensor units 16, 16' on the track rail 2 enables a comprehensive analysis of strains, in particular stress and / or load. The symmetrical arrangement is advantageous, but optional.

[0092] The two sensor units 16, 16' can be components of the same sensor assembly 3 or belong to separate sensor assemblies 3, 3'. Sensor units 16, 16' belong to the same sensor assembly 3 if they are structurally and / or signal-transmittingly connected and / or connected to the evaluation unit 5 via a common connection, in particular via a single signal line. The sensor unit 16 is described in more detail with reference to Fig. 4. Fig. 4 shows the side of the sensor unit 16 facing the track rail 2. The optical fiber 33 is attached to the first support 28. In the area of ​​the first support 28, this forms the two strain sensors 30.1, 31.2, whose respective measuring directions 35.1, 35.2 are arranged obliquely to the longitudinal direction 21 and to a vertical direction 36.

[0093] For a particularly precise arrangement of the light-conducting fiber 32 in the area of ​​the strain sensors 30.1, 30.2, it is attached to support elements 37. The respective support element 37 can be made of a metallic material and / or a plastic, in particular, it can consist of the latter.

[0094] To form the respective strain sensor 30.1, 30.2, a section preferably extends in the light-conducting fiber 32 between two of the support elements 37. In particular, the respective fiber bracing grid is arranged, especially centrally, between each pair of support elements 37.

[0095] The strain sensors 30.1, 30.2 are arranged at a small distance from the first measuring point 19 or directly at the measuring point 19. A distance can be present, in particular, if a sensor unit 16, 17, 23 has several strain sensors 30.1, 30.2, 31.1, 31.2. However, the distance is preferably so small, or the arrangement of the strain sensors 30.1, 30.2, 31.1, 31.2 is selected such that displacement effects due to the distance are small and / or can be compensated for or eliminated computationally.

[0096] The sensor device 3, in particular the respective sensor unit 16, 17, 23, can have a positioning stop 38, in particular in the form of circumferential recesses, which are designed to reversibly detach and positively lock the position and orientation of the sensor device 3, in particular the respective sensor unit 16, 17, 23, in particular relative to an application device 39.

[0097] The support elements 37 and / or the optical fiber 32 can be arranged on a surface of the sensor unit 16, 17, 23. This makes the transmission of strains between the track rail 2 and the respective strain sensor 30.1, 30.2 particularly direct and precise. The multiple strain sensors 30.1, 30.2, 31.1, 31.2 are preferably formed by the same or a single optical fiber 32. Between the sensor units 16, 17, the optical fiber 32 is preferably guided or supported by the coupling means 18.

[0098] A measurement signal line 40, in particular a cable- and / or ribbon-shaped measurement signal line, which includes the optical fiber 32, can be formed between two pairs of sensor units 26. The measurement signal line 40 can form the loop 27.

[0099] Preferably, the sensor device 3, in particular the coupling means 18, 25, comprises several, in particular at least two, in particular at least three, in particular at least five, measuring signal lines 40. This allows the sensor device 3 to have a particularly high number of strain sensors 30.1, 30.2, 31.1, 31.2.

[0100] The sensor device 3, 3', in particular the coupling means 18, 25, can include a temperature sensor (not shown). The temperature sensor can be designed as a fiber optic temperature sensor and / or as a film sensor. This allows temperature influences to be determined and / or compensated for.

[0101] The sensor device 3 is preferably designed to be flexible, in particular foldable and / or rollable or unrollable.

[0102] The operating principle of the measuring system 6, the measuring arrangement 1 or the sensor device 3 is as follows:

[0103] Initially, track 10 can be operational but without the sensor device 3, 3'. To set up the measuring arrangement 1, the sensor device 3, 3' is attached to the track rail 2. Due to its considerable length, the sensor device 3, 3' is preferably transported to track 10 in a folded and / or wound-up state, in particular wound onto a reel.

[0104] The surface of the track rail 2, particularly in the area of ​​the rail web 14, can be sanded and / or degreased and / or cleaned. Adhesive can be applied to the track rail 2 and / or the sensor device 3, 3', particularly the respective support 28, 29, to form the adhesive layer 34.

[0105] The sensor device 3, 3', in particular the sensor units 16, 17, 23, can be pressed and / or glued to the track rail 2, preferably one after the other. The application device 39, described in more detail below, can be used for this purpose.

[0106] The arrangement of the sensor device 3, 3', in particular the sensor unit pairs 36, in particular the sensor units 16, 17, 23, is carried out in accordance with the above description, in particular as explained with reference to Figs. 1 to 4.

[0107] To protect the sensor device 3, 3', in particular the sensor units 16, 17, 23 and / or the adhesive layer 34, the sensor units 16, 17, 23 and / or the coupling means 18, 25 are preferably sealed with a covering means 41. Preferably, the sensor units 16, 17, 23 are enclosed by the covering means 41 and the track rail 2 in a liquid-tight, in particular moisture-tight, manner.

[0108] The sensor unit 3, 3' is connected to the evaluation unit 5 via signal transmission. A signal connection can be established between the evaluation unit 5 and the signal box 8.

[0109] The measuring system 6, the measuring arrangement 1 or the sensor device 3, 3' are completed.

[0110] The sensor device 3, 3' can be calibrated by means of a test run. For this purpose, a rail vehicle 9 with a known weight m can be moved along the track 10. The measurement signals acquired by the sensor device 3, 3', in particular by the strain sensors 30.1, 30.2, 31.1, 31.2, can be unambiguously assigned to the known mass of a passing rail vehicle 9. If necessary, the calibration is carried out by means of several test runs, in particular with rail vehicles 9 of different, known weights m. This can further increase the precision of the calibration. The measuring system 6, the measuring arrangement 1, and the sensor device 3, 3' are ready for operation.

[0111] The measurement signals of the sensor device 3, 3' can be evaluated by means of the evaluation device 5 in order to determine, for example, the stress and / or the load on the track 10, in particular the track rail 2, and / or a property of the rail vehicle 9, in particular its weight and / or condition, in particular the concentricity of the wheels of the rail vehicle 9, and / or the condition of the track 10, in particular for the detection of defects and / or cracks in the track rail 2 and / or the track sleepers 11, and / or for the detection of the compaction state of the ballast bed 12, in particular for detecting voids in the ballast bed 12, in particular under the track sleepers 11.

[0112] Furthermore, the evaluation of the sensor signals ensures the precise determination of the position of a rail vehicle 9, a train completeness check and / or a speed measurement.

[0113] The measuring system 6, the measuring arrangement 1, and the sensor device 3, 3' ensure comprehensive, flexible, and precise recording of the stresses acting on the track rail 2. From these, detailed conclusions can be drawn about the loads acting on track 10, in particular about the condition of track 10 and rail vehicles 9. Furthermore, the recorded signals can be used to control rail traffic. The measuring system 6, the measuring arrangement, and the sensor device 3 increase the operational safety, efficiency, and reliability of a rail traffic system designed with this system.

[0114] Figures 5A to 6F describe further embodiments of different sensor units 16, 16', 17, 23:

[0115] The sensor unit 16 shown in Fig. 5A differs from the sensor unit 16 described above in that it has only one strain sensor 30.1 instead of two strain sensors 30.1, 30.2. This also allows shear strains to be detected with sufficient accuracy, at least for certain applications. The sensor unit 16 shown in Fig. 5B additionally includes a strain sensor 30.3, the measuring direction 35.3 of which is oriented parallel to the longitudinal direction 21. The additional strain sensor 30.3 ensures the detection of longitudinal strains of the track rail 2.

[0116] The sensor unit 16 shown in Fig. 5C comprises, in addition to the sensor unit 16 described above, two strain sensors 30.4, 30.5, whose measuring directions 35.4, 35.5 are vertically oriented, in particular perpendicular to the longitudinal direction 21. The additional strain sensors 30.4, 30.5 ensure the detection of transverse strains in the track rail 2, in particular in the rail web 14 and / or in the rail head 13 and / or in the rail foot 15.

[0117] Figure 5D shows the two sensor units 16, 16' described above for reference. The sensor units 16, 16' are components of separate sensor devices 3, 3'.

[0118] Figure 5E shows two sensor units 16, 16' which are structurally and / or signal-transmittingly connected via a coupling means 25. The sensor units 16, 16' and the coupling means 25 are components of the same sensor assembly 3.

[0119] Figure 5F shows two sensor units 16, 16' which are connected to each other by a coupling means 25, in particular structurally and / or by signal transmission, and are components of the same sensor device 3. In contrast to the embodiment described above, a further strain sensor 30.6 is arranged on the coupling means 25. A measuring direction 35.6 of the strain sensor 30.6 is oriented parallel to the longitudinal direction 21. The strain sensor 30.6 is arranged on the coupling means such that it can be attached to the rail foot 15. The coupling means 25 ensures precise positioning of the strain sensor 30.6 relative to the strain sensors 30.1, 30.2 of the sensor unit 16. The strains, in particular longitudinal strains, at the rail foot 15 can be detected by means of the strain sensor 30.6.

[0120] The manufacture of the measuring arrangement 1 is described in further detail with reference to Fig. 6A. The application device 39 is attached to the track rail 2. It is supported by the rail foot 15 and the rail head 13. For this purpose, the application device 39 has corresponding fastening means 42.1, 42.2 for connecting it to the rail head 13 and the rail foot 15. These can be articulated together. A clamping ram 43 can clamp the sensor unit 16 against the track rail 2. Preferably, the clamping ram 43 includes a thread 44 for exerting the clamping force. The clamping ram 43 can have a layer 43a made of an elastic material, particularly to compensate for unevenness between the application device 39 and the sensor unit 16.

[0121] The application device 39, in particular the pressure plunger 43, can have a counter-positioning stop 45 for precise positioning and / or alignment of the sensor unit 16 relative to the track rail 2.

[0122] Figure 6B shows the sensor unit 16 with an additional strain sensor 30.6 for the rail foot 15. The sensor unit 16, together with the track rail 2, is enclosed by the covering material 41 in a liquid-tight, and in particular moisture-tight, manner. The covering material 41 can be made of, and in particular consist of, a plastic.

[0123] The sensor units 16, 16' according to Fig. 6C largely correspond to those according to Fig. 3. In contrast, the coupling means 25 is formed by the material of the supports 28, 29. A rigid, in particular flexurally stiff, structure for connecting the two sensor units 16, 17 of a sensor pair 26 is not provided.

[0124] Furthermore, an alternative embodiment of an application device 46 is described with reference to Fig. 6C. This device can be used with any sensor units 16, 16'. The application device 46 comprises at least one magnet 47, preferably a permanent magnet, alternatively an electromagnet, for attaching it to the linear infrastructure component 2, in particular the track rail, and especially for exerting a contact force on the sensor units 16, 16'. The contact plunger 43 can otherwise be designed like that of the application device 39.

[0125] Fig. 6D shows an asymmetric arrangement of the sensor units 16, 16'.

[0126] Figure 6E shows an embodiment largely corresponding to Figure 5E. Figure 6F shows an embodiment in which the sensor device 3 has a symmetrical structure with strain sensors 30.1, 30.2 on the rail web 14 and strain sensors 30.6 on the rail foot 15.

Claims

Patent claims 1. Sensor device (3, 3') for detecting strains on a linear infrastructure component (2), in particular a track rail, comprising 1.1 a first sensor unit (16, 16'), with 1.1.1 a first carrier (28), and 1.1.2 at least one strain sensor (30.1 to 30.6) received by the first support for detecting strain at the first measuring point (19), 1.2 a second sensor unit (17), with 1.2.1 a second carrier (29), and 1.2.2 at least one strain sensor (31.1, 31.2) received by the second support (29) for detecting a strain at the second measuring point (20), 1.3 a coupling means (18) connected to the first support (28) and the second support (29) for defining a measuring distance (d) between the first measuring point (19) and the second measuring point (20) along a longitudinal direction (21) of the linear infrastructure component (2).

2. Sensor device (3, 3') according to claim 1, characterized in that it is designed for application on a rail web (14) of the track rail (2).

3. Sensor device (3, 3') according to claim 1 or 2, characterized in that the measuring distance (d) between the first measuring point (19) and the second measuring point (20) is in a range of 10 cm to 120 cm.

4. Sensor device (3, 3') according to one of the preceding claims, characterized in that the coupling means (18) and / or the first support (28) and / or the second support (29) are designed to be flexible.

5. Sensor device (3, 3') according to one of the preceding claims, characterized in that the at least one strain sensor (30.1 to 30.6, 31.1, 31.2) is a fiber optic strain sensor, in particular a fiber Bragg grating sensor.

6. Sensor device (3, 3') according to claim 5, characterized in that the at least one strain sensor (30.1 to 30.6, 31.1, 31.2) is a fiber Bragg grating sensor.

7. Sensor device (3, 3') according to claim 5 or 6, characterized in that at least one strain sensor (30.1 to 30.6) of the first sensor unit (16, 16') and at least one strain sensor (31.1, 31.2) of the second sensor unit (17) is designed as fiber optic strain sensors of the same optical waveguide (32).

8. Sensor device (3, 3') according to one of the preceding claims, characterized in that the coupling means (18) carries at least one measuring signal line (40) for conducting a measuring signal between the first sensor unit (16, 16') and the second sensor unit (17).

9. Sensor device (3, 3') according to one of the preceding claims, characterized in that the coupling means (18) carries at least two separate optical waveguides (32).

10. Sensor device (3, 3') according to one of the preceding claims, characterized in that the first sensor unit (16, 16') comprises at least two strain sensors (30.1 to 30.6) for detecting a strain at the first measuring point (19).

11. Sensor device (3, 3') according to one of the preceding claims, characterized in that the measuring direction (35.1 to 35.6) of the at least one strain sensor (30.1 to 30.6, 31.1, 31.2) is oriented obliquely to the longitudinal direction (21) of the linear infrastructure component (2).

12. Sensor device (3, 3') according to claim 11, characterized in that the measuring direction (35.1 to 35.6) of at least one strain sensor (30.1 to 30.6, 31.1, 31.2) of the first and second sensor units (16, 16', 17) is oriented obliquely to the longitudinal direction (21) and obliquely to the vertical direction (36) of the linear infrastructure component (2).

13. Sensor device (3, 3') according to one of the preceding claims, characterized by at least one strain sensor (30.3) whose measuring direction (35.3) is aligned parallel to the longitudinal direction (21) of the linear infrastructure component (2).

14. Sensor device (3, 3') according to one of the preceding claims, characterized by at least one strain sensor (30.3) whose measuring direction (35.3) is oriented perpendicular to the longitudinal direction (21) of the linear infrastructure component (2), in particular vertically.

15. Sensor device (3, 3') according to one of the preceding claims, characterized by at least one temperature sensor, in particular on the first and / or the second carrier (28, 29) and / or on the coupling means (18).

16. Sensor device (3, 3') according to claim 15, characterized in that the at least one temperature sensor is a fiber optic strain sensor, in particular a fiber Bragg grating sensor.

17. Sensor device (3, 3') according to claim 15 or 16, characterized in that the at least one temperature sensor and at least one of the strain sensors (30.1 to 30.6, 31.1, 31.2) are formed by the same light-conducting fiber (32).

18. Sensor device (3, 3') according to one of the preceding claims, characterized by a positioning stop (38) for reversibly releasable positive locking fixing of the position and orientation of the sensor device (3, 3') relative to an application device (39) and / or to the linear infrastructure component (2).

19. Sensor device (3, 3') according to one of the preceding claims, characterized by at least one further sensor unit (23), each with a further carrier (23a) and at least one strain sensor mounted on the further carrier (23a) for detecting a strain at a further measuring point (24), and by a further coupling means (25) for connecting the further sensor unit (23) to an adjacent sensor unit (16, 16', 17, 23).

20. Sensor device (3, 3') according to one of the preceding claims, characterized in that at least two of the measuring points (19, 20) have a distance of at least 0.6 m, in particular at least 2 m, in particular at least 4 m, in particular at least 10 m.

21. Sensor device (3, 3') according to one of the preceding claims, characterized in that it is designed to be coilable and / or foldable.

22. Measuring arrangement (1), comprising 22.1 a linear infrastructure component (2), in particular a track rail, and 22.2 a sensor device (3, 3') materially bonded to the linear infrastructure component (2) according to one of the preceding claims, 22.3 wherein the two measuring points (19, 20) are arranged on the linear infrastructure component (2) at the measuring distance (d) determined by the coupling means (18).

23. Measuring arrangement (1) according to claim 22, characterized in that the first and the second measuring point (19, 20) are arranged on a rail web (14) of the track rail (2).

24. Measuring arrangement (1) according to claim 22 or 23, characterized in that the first and the second measuring point (19, 20) are arranged in the neutral fiber (33) of the track rail (2).

25. Measuring arrangement (1) according to one of claims 22 to 24, characterized by a covering means (41) which, together with the linear infrastructure component (2), seals the first and the second sensor unit (16, 16', 17) in a liquid-tight, in particular moisture-tight, manner.

26. Measuring arrangement (1) according to one of claims 22 to 25, characterized in that the first and the second measuring point (19, 20) are arranged in the longitudinal direction (21) between two adjacent track sleepers (11).

27. Method for applying a sensor device (3, 3') to a linear infrastructure component (2), in particular a track rail, comprising the steps: 27.1 Providing a sensor device (3, 3') according to one of claims 1 to 21, 27.2 Attaching the sensor device (3, 3') to the linear infrastructure component (2) such that the two measuring points (19, 20) on the linear infrastructure component (2) are arranged at the measuring distance (d) determined by the coupling means (18).

28. Method according to claim 27, characterized by positioning and aligning the sensor device (3, 3') by means of an application device (39) which interacts positively with a positioning stop (38) of the sensor device (3, 3').

29. Method according to claim 27 or 28, characterized by calibrating the sensor device (3, 3'), wherein the strains are detected when a rail vehicle (9) with known weight (m) passes over the track rail (2).

30. Application device (39) for applying a sensor device (3, 3'), in particular according to one of claims 1 to 21, to a linear infrastructure component (2), in particular a track rail (2), comprising 30.1 a fastening means (42.1, 42.2) for reversibly detachable positive locking fixing the position and orientation of the application device (39) relative to the linear infrastructure component (2), and 30.2 a counter-positioning stop (45) for reversibly detachable positive locking fixing of the position and orientation of the sensor device (3, 3') relative to the application device (39).

31. Application device (39) according to claim 30, characterized by at least one magnet (47) for attaching the sensor device (3, 3') to the track rail (2).

32. Application device (39) according to claim 31, characterized in that the magnet (47) is a component of a pressure plunger (43) for exerting a pressure force on the at least one sensor unit (16, 16', 17).

33. Application device (39) according to one of claims 30 to 32, characterized by at least one clamping means (44) for exerting a clamping force on the at least one sensor unit (16, 16', 17), wherein the fastening means (42.1, 42.2) is designed such that a reaction force corresponding to the clamping force clamps the fastening means (42.1, 42.2) into a locking position in which the fastening means (42.1, 42.2) is immovably fixed to the linear infrastructure component (2).

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