DEVICE FOR MEASURING AT LEAST ONE KINEMATIC PARAMETER OF A PORTION OF A STRUCTURAL ELEMENT

The present invention relates to a device for measuring at least one kinematic parameter of a portion of a structural element, in particular a structural element with a main extension direction.

Preferably, but not exclusively, the invention pertains to the field of railways for detecting track (rail, sleeper) deflection during transit of a train. Measuring devices are known in this field which can be applied to a railway rail and which are capable of measuring the deflection of the rail during passage of a train. These devices are based on the relative measurement between a situation of normal rail position and a transit situation.

However, there are several problems with these systems.

Detection takes place for a predetermined period during which one or more trains pass through. This requires that the device and any auxiliary systems are operated for the entire period and that, during the entire period, they acquire detection data that are stored and processed. The length of this period therefore negatively affects the efficiency of the process, which requires management of a huge amount of data only a small part of which is actually relevant. Alternatively, the presence of at least one operator is required to activate and deactivate data acquisition only when trains are passing through.

In addition, the known devices require complex systems for anchoring the device to the rail that require long installation and fine-tuning times, especially if the measuring system requires the use of multiple individual measuring devices.

The technical task of this invention is therefore to make available a device for the measurement of at least one kinematic parameter of a portion of a structural element that can overcome the limitations of the prior art mentioned above. Within the scope of this technical task, it is the primary aim of the invention to provide a device for measuring at least one kinematic parameter of a portion of a structural element of high operational efficiency, in particular one that optimises the amount of experimental data acquired and therefore optimises the process of storing and processing the data acquired.

It is also a subject matter of the invention to provide a device for measuring at least one kinematic parameter of a portion of a structural element which can be easily installed at the place of measurement.

The specified technical task and the specified purpose are substantially achieved by means of a device for measuring at least one kinematic parameter of a portion of a structural element containing the technical characteristics of claim 1 and/or in one or more of the claims dependent thereon.

Within the scope of the present invention, the term “structural element” means an element having a dimension of development that is very predominant over the other two dimensions. By way of example, a structural element to which the present invention preferably applies is a railway rail; however, other structural elements such as cables or the like or, in accordance with different applications, also generic structural elements having different geometries, are also contemplated as long as they are subject to the propagation of a disruptive phenomenon or exposed to a measurable external disruptive phenomenon.

In accordance with the invention, the device is configured to be permanently applied to the structural element and comprises at least one sensor for detecting at least one kinematic parameter of the structural element, and is further configured to activate automatically upon the approach of a disruptive event propagating along the structural element and/or upon detection of the disruptive event propagating along the structural element.

In other words, the device is configured to determine the instant in which the phenomenon to be detected is sufficiently close in accordance with a predetermined criterion, and this is achieved by measuring the extent of the disruptive phenomenon along the structural element and activating the measurement of the kinematic parameter only after the instant of activation.

It is therefore the case that the device is configured to perform two distinct functions: detection of the disruptive phenomenon along the structural element and measurement of the kinematic parameter of the structural element. In this context, the kinematic parameter is linked to a local deformation movement of the structural element related to the disruptive phenomenon.

In one embodiment, detection of the disruptive phenomenon along the structural element and measurement of the kinematic parameter of the structural element are performed by different sensors. For example, detection of the disruptive phenomenon along the structural element is can be achieved using an accelerometer, while measurement of the kinematic parameter of the structural element can be achieved using a separate sensor, for example a linear transducer, an optical sensor (which can be what is termed a photodiode array), a different accelerometer or other.

In a different embodiment, detection of the disruptive phenomenon along the structural element and measurement of the kinematic parameter of the structural element are achievable by the same sensor, for example an accelerometer.

In one embodiment, the disruptive phenomenon comprises a vibration that is transmitted along the structural element.

In another embodiment, the kinematic parameter is a deformation of the structural element, for example a flexural deformation under load (deflection) or a torsional inclination along the axis of the structural element.

In accordance with variants of the invention, the device may be intended for the acquisition of information such as load (e.g. an instantaneous stress state of the structural element), noise level, temperature, or audio/video images. In all these cases, activation of data acquisition is subject to the measurement of the disruptive phenomenon that constitutes the discriminating factor in the activation or otherwise of data acquisition.

For this reason, detection of the disruptive phenomenon is an action that is preferably kept in operation, continuously and/or permanently, as it is generally not possible to predict exactly the time at which the disruptive event is generated and therefore the time at which measurement of the kinematic parameter should be activated.

Conversely, the action of measuring the kinematic parameter is a function that can normally, or at least temporarily, be deactivated (“dormant” configuration) and that is activated (“operational” configuration) in the event that detection of the disruptive phenomenon provides a result of an imminent disruptive phenomenon or one that is placed at a predetermined distance (physical or temporal).

Furthermore, in accordance with an aspect of the invention, measurement of the kinematic parameter can be activated in a controlled and/or timed manner to operate isolated detections of the kinematic parameter in a situation without the disruptive phenomenon. This detection thus provides data that can be used as reference values comparable with survey results obtained during the disruptive phenomenon in order to evaluate the deviations and, therefore, the extent of the movement or the kinematic magnitude of the structural element.

In accordance with an aspect of the invention, management of the controlled activation of the measurement of the kinematic parameter following the monitoring of the disruptive phenomenon takes place by means of a special control unit, which can be inside the device (for example in the case of devices used in isolation) or outside the device (for example in the case of devices used in a group and managed centrally).

According to one embodiment, during dormant configuration (i.e., in the absence of a disruptive phenomenon) detection of the kinematic parameter is programmed to be activated with a predetermined frequency, for example every two minutes, while during operational configuration a specific higher acquisition frequency is provided, for example between 50 Hz and 1 kHz, preferably equal to about 350 Hz.

It is also preferable for the detection of the presence of the disruptive phenomenon to be carried out by means of acquisition at a specific frequency. This frequency is, for example, comprised between 50 Hz and 1 kHz, preferably about 350 Hz.

In accordance with an aspect of the invention, activation of the detection of the kinematic parameter is operated when the disruptive event is above a predetermined threshold, in particular above a predetermined amplitude or frequency (in the case of vibration as a disruptive event).

Preferably, a control unit is further configured to deactivate detection of the kinematic parameter after a predetermined time from activation of the operating configuration and/or from an instant when the disruptive event falls below a predetermined threshold, in particular below a predetermined amplitude and/or frequency. In the first case, this allows automatic deactivation at a time when the disruptive event is presumed to have ended and, in the second case, automatic deactivation at the exact end of the event (or at a time having a predetermined relationship with the end of the event).

Preferably, the device comprises an accelerometer configured to detect a vibration of the structural element (as a parameter identifying the incoming or approaching disruptive phenomenon) and the device is configured to activate when the vibration detected by the accelerometer assumes a property higher than a predetermined threshold, in particular a vibration amplitude and/or frequency. In one embodiment, the accelerometer is dedicated only to the function of detecting said vibration and the device therefore comprises one or more sensors, separated from the accelerometer, used to detect one or more kinematic parameters of the structural element, for example a deflection, a vibration, a temperature or other.

In a different embodiment, the accelerometer (or also, depending on the needs of the moment, an overall number of accelerometers greater than one) is also used to detect one or more kinematic parameters of the structural element, for example a vibration acceleration of the structural element, and it therefore defines the sensor forming part of the device.

Preferably, the sensor comprises at least one of the following: a linear deviation sensor, preferably of the optical type, an inclination sensor, or an accelerometer. Also ideally, said at least one sensor should be of the Micro Electro-Mechanical Systems (MEMS) type.

In one embodiment, the device is configured to detect one or more kinematic parameters of a component of a railway track, preferably a railway rail, and the aforementioned sensor comprises (preferably, but not limited to) a linear transducer. In such a configuration, the device includes:

- a fixing portion provided with one or more gripping elements, preferably magnets, and configured to couple in a stable manner to a planar surface of said structural element, in particular the lower surface of the foot of a railway rail; and

- a support base that can be coupled stably to a fixed support surface, in particular railway ballast, to assume a stationary configuration during operation of the device.

The linear transducer is arranged and/or configured to measure a linear displacement between the fixing portion and the support base, thus corresponding to the deflection of the rail during passage of a train. In greater detail, the linear transducer can directly measure a position of instantaneous relationship between the fixing portion and the support base, the variation in time of which defines the vertical displacement of the rail.

A measuring chamber, within which the upper part of a sliding stem attached to the bottom of the support base is slidably received, is attached to the fixing portion. The linear transducer, which in this embodiment is preferably made with a laser/optical instrument, is arranged inside the measuring chamber and configured to measure displacement of the sliding stem (or, more generally, the instantaneous position of an end of the sliding stem placed in the measuring chamber).

Operationally, then, the fixing portion is removably coupled to the lower base surface of the foot of the rail (or by other means to other portions of the track, for example to a sleeper) in such a way that the sliding stem is arranged in a substantially vertical orientation. During transit of a train, the sensor then acquires, at the predetermined frequency and for a predetermined time, a sequence of readings from which it is possible to obtain the trend of the lowering of the rail over time.

In an embodiment not illustrated, the device comprises two support bases having respective stems both slidably mounted on the fixing portion (two- support configuration of the device) and each associated with a respective sensor, the cover casing preferably being single and enveloping both sensors.

Preferably, the device comprises an internal electronic control unit configured to provide power to the sensor(s) and dynamically to acquire the data received from the sensor and possibly to process said data.

Again ideally, the device returns information comprising at least one detected value and the corresponding instant of detection, for example in the case of detection of rail lowering, the device may return the maximum deflection value (determined by the internal electronic control unit) and the corresponding instant of detection.

In one embodiment, the device is energy autonomous. For example, it may be powered by an internal accumulator, preferably rechargeable, or by solar panels or both.

Also forming part of the subject matter of the invention is a method for measuring at least one kinematic parameter of a railway rail, in particular at least the lowering and/or inclination of the rail following transit of a train, said method being operated by means of at least one device according to the present invention.

The method includes a phase of permanently applying the device to the railway rail, in particular by means of magnetic connection to a lower surface of the foot of the rail and preferably exclusively by means of said magnetic connection to the lower surface of the foot of the rail. Subsequently, the method entails detecting, in a dormant configuration, a vibrational state of the rail. The vibrational state of the rail is in fact directly related to the transit of a train, since, as a train approaches (even if at a certain distance), the rail becomes a propagation site of vibrational waves travelling at a higher speed than the train and therefore anticipating the latter, intrinsically conveying information of an approaching train which can be used to activate the sensor according to the methods provided for by the invention.

The method therefore comprises a phase of automatically activating the device’s sensor when the vibrational state of the rail is greater than a predetermined threshold corresponding to a railway train in transit, so as to detect said at least one kinematic parameter of the rail during passage of the train.

Preferably, the method further comprises a step of temporarily activating the sensor during the dormant configuration to perform isolated detections, particularly at predetermined time intervals, and to store the detections and/or to send the detections to a receiving device, wherein at least one of the isolated detections defines a reference measurement.

The method also comprises a step of processing the detections carried out by the sensor at least to calculate a difference between each detection and the reference measurement, thus obtaining a succession of lowering and/or inclination values of the rail during transit of a train. To obtain the best results, in this step (and more generally in the detection operations that can be carried out through the subject matter of the present invention) measurement of inclination and temperature (during a given “event” that generates vibrations and/or deflection in the object on which the measurements are to be carried out) can be conveniently performed in conditions where vibrations are absent, precisely to avoid the influence of the event itself.

More generally, in a generic application to a structural element, the method provides a step of applying the device to the structural element by connecting the fixing portion to the structural element and the support base to a fixed reference surface, and a subsequent step of monitoring the presence of a disruptive event through the structural element. The method further provides for automatic activation of the acquisition of at least one status parameter of the structural element, in particular a kinematic parameter (displacement, acceleration, speed, vibration, inclination or other) or other parameter (for example temperature, state of tension, load, noise or other) when the disruptive event reaches and/or exceeds a minimum value. In these circumstances, occurrence of the disruptive event is ascertained and therefore such as to warrant activation of data acquisition by the sensor.

A further subject matter of the invention is an installation for monitoring the dynamic behaviour of a railway rail, comprising:

- a plurality of measuring devices according to the invention, each device being applied to a corresponding portion of the lower surface of the foot of the rail and in particular each device being applied in isolation to a respective section of rail comprised between consecutive sleepers;

- a common control unit, connected to the control units of the measuring devices by cables, or wirelessly, and configured to operate a dormant configuration, wherein the sensors of the measuring devices are at least temporarily deactivated and corresponding to a situation of no propagation of disturbance through the rail, and an operative configuration, wherein the sensors of the measuring devices are activated to actuate, preferably in real time, a sequence of detections of said at least one kinematic parameter.

Preferably, the control unit is also configured to activate the sensors temporarily during the dormant configuration to perform isolated detections, in particular at predetermined time intervals, and to store the detections and/or send them to a receiving device.

The present invention will now be described with reference to the accompanying drawings which, by way of example only, illustrate implementation thereof, wherein:

- Figure 1 is a perspective view of a measuring device according to the present invention;

- Figure 2 shows the device in Figure 2 with some parts removed in order to highlight others more effectively;

- Figures 3 and 4 represent a front view of the device in Figure 1 in accordance with two different operating situations;

- Figure 5 shows a sectional view, in a vertical plane, of the device in Figure 1 ;

- Figure 6 is a sectional view of the device in Figure 1 according to the VIVI axis in Figure 5;

- Figure 7 illustrates an application configuration of the device in Figure 1 to a railway rail.

With reference to the appended Figures, Figure 1 represents overall a measuring device according to the present invention.

The measuring device 1 disclosed and illustrated is optimised for application to a railway rail for measuring the deflection and/or the inclination of the rail during the transit of a train; however, the invention is applicable to different technical fields and therefore can have different configurations and optimisations depending on the specific application and at any rate falling within the same inventive concept.

The device 1 includes a fixing portion 2 configured for stable application to the lower planar surface of the foot of a railway rail (Figure 5). The fixing portion 2, which will be disclosed in detail below, is substantially located centrally along the vertical development of the device 1 .

In the embodiment illustrated, the fixing portion 2 is substantially plate- shaped and configured to orientate substantially parallel to the lower surface of the foot of the rail.

On the upper side of the fastening plate 2, a cover casing 3 of preferably closed form, and for example substantially box-shaped, is stably applied, internally enclosing a detection chamber 4. At least one sensor 5 is arranged in the detection chamber 4 which, in the embodiment of the appended Figures (visible in Figures 5 and 6), is a linear transducer preferably made in the form of an optical sensor (for example a laser). Furthermore, in the illustrated embodiment, the sensor 5 is stably applied to the top of the cover casing 3.

The fixing portion 2 is also configured to receive slidably a stem 6 along a sliding direction substantially perpendicular to the rest of the fixing portion 2, which is to say substantially vertical. Preferably, the fixing portion 2 has a guide portion 2a within which the stem 6 slides sealingly by means of an annular gasket 2b.

As can be seen in Figures 5 and 6, the stem 6 has an upper portion 6a normally contained in the detection chamber 4 and a lower portion 6b arranged below the fixing portion 2.

The bottom portion 6b of the stem 6 is provided at the end with a resting plate 7 suitable for fastening to and/or resting on a reference surface, the bottom portion 6b of the stem 6 and the plate 7 defining a support base for the device 1. In the illustrated embodiment, the plate 7 is intended for stable support on the railway ballast, defining an essentially immovable surface during passage of a train (or at least a portion of the ballast sufficiently distant from the sleepers).

Furthermore, the lower portion 6b of the stem 6 is subjected to the contrasting action of a compression spring 8 configured to keep the plate 7 pushed downwards, away from the fixing portion 2 (Figure 3), and compressible during lowering of the rail (Figure 4). Preferably, the compression spring 8 is a helical spring arranged externally to the stem 6 and coaxially thereto. Preferably, moreover, the compression spring 8 is directly interposed between a lower surface of the fixing portion 2 and an upper surface of the plate 7.

Furthermore, a flexible protection element 9 can be arranged between the fixing portion 2 and the plate 7, which completely wraps the lower portion 6b of the stem 6 (and the compression spring 8, where provided). Preferably, said flexible protection element 9 is made in the form of a tube buffer.

The upper portion 6a of the stem 6 terminates with an end 6c facing the sensor 5 and in particular arranged so that the longitudinal axis of the stem 6 is aligned with the sensor 5 (the axis passes through the sensor). In greater detail, the upper portion 6a of the stem 6 ends with, or has, a disk 10 suitable for optical detection by the sensor 5, for example by reflection (Figure 5).

In the specific embodiment illustrated in Figures 5 and 6, the cover casing 3 has an internal wall 1 1 extending in a substantially vertical direction and such as to define a sub-chamber 1 1 a within which the aforementioned disk 10 slides, to size or with a minimum clearance. In this sub-chamber 1 1 a, the position of the disk 10 is detected by optical reflection (laser) by means of the sensor 5.

The detection of the position of the disk 10 by the sensor 10 determines a position reading of the stem 6 with respect to the fixing portion 2 and then determines the instantaneous position in the vertical direction of the rail 100 with respect to the ballast, on which the plate 7 rests.

The device 1 further comprises a control unit, in particular an internal electronic control unit, not illustrated, which can be housed within the same body in which the sensor 5 is arranged, then also placed on the top of the detection chamber 4, or in another position inside the detection chamber 4 (or even outside it) and connected to the sensor 5 by wiring.

The internal electronic control unit is active on the sensor 5 to activate and deactivate the sensor 5 according to the criteria that will be illustrated below. In addition, the internal electronic control unit may be connected to energy storage means, for example batteries, and/or to self-sustaining energy means, for example solar panels or other means suitable for generating electricity from an existing energy source. In this way, the device 1 is energy autonomous.

In addition, or as an alternative to such energy self-sustainment, the device 1 can be connected to an electrical power source by means of wiring. However, it remains evident that the absence of external connections via wiring makes the device 1 very versatile and possibly connectable functionally by wireless means to remote or remote units.

Advantageously, the device 1 is configured to determine the instant in which the transit of a train is imminent (phenomenon to be detected) and for this purpose the device is configured to measure the extent of the mechanical vibrations (disruptive phenomenon) induced by the train on the rail and which are transmitted along the rail at a much higher speed than the train, allowing the arrival of the train to be anticipated by implementing the preliminary procedures of preparation for measurement by the sensor 5.

For this purpose, the device 1 includes an accelerometer (not shown) connected to the internal electronic control unit and configured to detect the mechanical vibration induced on the rail, and therefore on the device 1 itself, by an approaching train.

Preferably, the acquisition of the accelerometer measurements by the internal electronic control unit takes place at a frequency comprised, for example, between 50 Hz and 1 kHz, preferably about 350 Hz.

Note that for consistent operation of the device that is the subject matter of the invention, the instrument/device comprises an optical sensor for measurement of bending (and said sensor is acquired with a sampling frequency within the range indicated above and preferably at 350Hz), while the detection of the disruptive event is carried out by an accelerometer sensor - for example, an MEMS - and said accelerometer sensor/MEMS has presently been programmed to make its acquisitions at 25Hz, and based on its own acquisitions is then functionally related to sending an activation trigger (i.e., a signal of effective commencement of the measurement by the optical sensor) in the event that a kinematic acceleration threshold appropriately pre-set as a “threshold value” (e.g. 0.3g) is exceeded.

The device 1 is thus configured to perform two distinct functions: detection of the disruptive phenomenon (vibration) along the rail, operated by the accelerometer, and measurement of the instantaneous vertical position of the rail 100, operated by the sensor 5 and influenced by the weight and running dynamics of the passing train.

The sensor 5 can also operate to detect, in addition to, or as an alternative to, the measurement of the instantaneous vertical position of the rail 100, as well as the inclination of the rail around its longitudinal axis (“tilting” of the rail). Depending on the needs of the moment and the available technological resources, this sensor can be of the “integrated” type and/or be able to detect several physical parameters, or multiple sensors may be set up that can be activated simultaneously, each of which is dedicated to the measurement of the respective physical parameters (for example, an optical linear measurement sensor, a temperature measurement sensor, a sensor for detection of the inclination and so on).

Preferably, vibration detection along the rail 100 is kept in operation, for example continuously and/or permanently, as it is generally not possible to predict accurately the time at which the transit of the train takes place and therefore the time at which the sensor needs to be activated.

Conversely, the action of measuring the vertical displacement of the rail during the passage of the train is a function that can normally be maintained or at least temporarily deactivated (dormant configuration) and that is activated (operational configuration) in the event that detection of vibration along the rail 100 provides a result of the imminent transit of a train. For this reason, the internal electronic control unit is configured to activate the sensor 5 when the vibration detected by the accelerometer is higher than a predetermined threshold (in amplitude and/or frequency), identified to cut any vibrations that are present but not attributable to the imminent transit of a train.

Moreover, it is preferable for the measuring action operated by the sensor 5 to be also operable in a commanded and/or timed manner to operate isolated detections of the vertical position of the rail 100 in a situation free of the passage of trains and therefore substantially free of deformation. This detection then provides data usable as reference values comparable with the detections obtained from the sensor in order to evaluate, by means of difference, the lowering magnitude of the rail 100 (deflection).

In accordance with an embodiment variant, management of the controlled activation of the measurement by the sensor 5 following the monitoring of the vibration of the rail 100 takes place by means of a control unit outside the device, for example in a configuration with a plurality of devices used in a group and managed centrally (devices located along the rail, for example at respective sections suspended between adjacent sleepers).

In one embodiment, during dormant configuration (i.e., in the absence of the transit of a train), programmed activation of the measurement by the sensor 5 with a predetermined frequency is provided, for example every two minutes, while during operational configuration (during transit of a train) a specific higher acquisition frequency is provided, for example between 50 Hz and 1 kHz, preferably about 350 Hz.

The internal electronic control unit is further configured to deactivate measurement on the part of the sensor 5 after a predetermined time from activation of the operating configuration and/or from an instant when the vibration of the rail falls below a predetermined threshold, in particular below a predetermined amplitude and/or frequency. This allows, in the first case, automatic deactivation at a time when it is assumed that the transit of the train has ended while, in the second case, it allows automatic deactivation at the exact moment the transit ends (or at an instant with a predetermined relationship with the end of the transit).

Preferably, the device 1 provides information comprising at least one detected value (lowest position reached by the rail 100 or greater deflection value) and the corresponding instant of detection.

In one embodiment, the device 1 is employed in conjunction with one or more other identical devices and is connected to an external management unit connected thereto via wiring or a wireless network. This external unit can itself define the control unit which is centrally controlled by the sensors 5 (i.e., the activation and deactivation of the sensors instead of the individual internal electronic control units of the devices 1 ).

In one embodiment, the reference value or “zero reading” (in the dormant phase) can be detected in a time range between 5 and 10 seconds before the start of the disruptive event (transit of the train), such that the reference value is not affected by the passage of the train; however, depending on the needs of the moment it is also possible to detect the reference value or “zero reading” in a different time frame with respect to the start of the disruptive event (e.g., by adopting what is termed a “trigger” of the “Indian ear” type, whereby what is termed the “zero reading” is made in a quiet moment and/or in the absence of vibrations that typically occurs after each disruptive event).

Furthermore, the control unit (internal electronic control unit or external management unit) includes a storage log equipped with an appropriate number of memory allocation zones, such as - in the embodiment mentioned solely by way of example - at least four measurement buffers: first event, second event, third event and fourth event.

At each new event, the data saved in the previous events is transferred to the next buffer so as to leave space for the newly measured event, entailing cancellation of the first saved event (the oldest) and constant storage of the last four events. With a two-minute acquisition rate (the rate at which the control unit reads), the control unit can ensure that no event is missed and that all events are detected and processed. In addition, the control unit may further comprise a time log having at least five allocation zones: current instant (period during which the device 1 has been activated) and first, second, third and fourth instants, corresponding to the instants in which the four events referred to in the measurement buffer described above have occurred. In this way, each measurement can be associated with the corresponding time instant in which it occurred.

With reference to the fixing portion 2, it is configured for the quick coupling of the device 1 to the foot of the rail 100, in particular to the lower planar surface 110 of the foot of the rail.

Such quick coupling methods comprise one or more permanent magnets 12 (two side by side in the illustrated embodiment) fixed to an upper surface 13 of the fixing portion 2 such that a lower surface of the magnets 12 faces the fixing portion 2 and the upper surface of the magnets 12 is free and magnetically coupled in contact with the lower planar surface 110 of the foot of the rail.

Preferably, the fixing portion 2 has a lateral band 14 defining the aforementioned upper surface 13 on which the magnets 12 are applied. This lateral band 14 protrudes laterally with respect to the vertical development of the cover casing 3 in such a way that when the device is applied to the rail 100, by means of attachment of the magnets 12 to the lower planar surface 110 of the foot of the rail, the cover casing 3 is arranged alongside the rail 100.

Preferably, in accordance with the illustrated embodiment, the magnets 12 are shaped as a disk or ring with a planar upper surface preferably calibrated in such a way as to define a precise coupling of the device 1 to the rail 100.

In addition, the aforementioned lateral band 14 can have one or more proximity sensors 15 to define a lateral stop for the foot of the rail 100 so as to establish a predetermined positioning of the device 1 with respect to the rail 100, for example so as not to interfere with the gauge of the passing trains. This invention achieves the proposed purposes, by overcoming the drawbacks complained of in the prior art.

The device according to the invention optimises the computational burden as well as energy consumption by activating the detection only for a predetermined period at the end of the disruptive event, thus reducing the amount of data acquired and processed.

Furthermore, the device according to the invention allows rapid application to the structural element (rail) and rapid disassembly, thanks to the use of fast coupling means (permanent magnets).