Method and control device for determining track damage

Abstract

A method for determining track damage to a track system (1) is described. Furthermore, a control device (20) designed to carry out the steps of the method is described. Furthermore, a condition monitoring system (100) with such a control device (20) is described.

Description

[0001] ZF Friedrichshafen AG File 304961 -DE-NP Friedrichshafen 102024209878.7 2025-07-30

[0002] Procedure and control device for determining track damage

[0003] Technical field

[0004] A method for determining track damage on a railway track system is described. Furthermore, a control device configured to execute the steps of this method is described. Finally, a condition monitoring system incorporating this control device is described.

[0005] State of the art

[0006] Rail vehicles are a crucial component of passenger and freight transport. For the long-term reliable operation of rail vehicles, it is advantageous to know the condition of the vehicles and the infrastructure, particularly the rail system, at all times in order to take appropriate maintenance and repair measures as needed. This prevents consequential damage and unplanned outages due to undetected defects. WO 2023 / 043801 A1 describes a condition monitoring system that can be used to determine the condition of a rail vehicle and a railway line. The condition monitoring system includes a sensor that records vibration data from the rail vehicle. The sensor could, for example, be an accelerometer. Furthermore, the system describes the use of data from a global navigation satellite system (GNSS) to determine the position of a monitoring device on Earth.

[0007] From DE 10 2009 042 359 A1, a method for determining the position of a rail vehicle is also known, in which two positioning methods are combined to achieve a position determination with higher reliability and availability. Firstly, navigation data from a satellite-based navigation system is used for position determination, and secondly, at those points where a rail vehicle crosses a balise, the known exact position of the respective balise is accessed. ZF Friedrichshafen AG File 304961 -DE-NP Friedrichshafen 102024209878.7 2025-07-30

[0008] Furthermore, the following information is available from the documents US 2020 / 0 290 659 A1 ,

[0009] US 2014 / 0 277 824 A1 and US 2020 / 0 317 238 A1 disclose further methods for monitoring tracks and for detecting damage to tracks of a railway track system using detected accelerations or vibrations.

[0010] Object of the invention

[0011] A method for determining track damage on a railway track system will now be described, which is improved particularly with regard to the accuracy of the results.

[0012] Description of the invention

[0013] A first aspect concerns a method for determining track damage on a railway track system. This method can be computer-implemented. Steps of the method can be executed by a control device. The track system can be a section of track within a railway network. The track system can comprise multiple track sections. The method can monitor the condition of the track section at a specific time or at several different times.

[0014] The method involves providing a rail vehicle equipped with an accelerometer for recording acceleration measurements and a GNSS antenna for recording geographic coordinates. One step of the method involves reading sensor coordinates that describe the position of the accelerometer relative to the GNSS antenna on the rail vehicle. In other words, the sensor coordinates describe the installation positions of the sensors on the rail vehicle relative to the GNSS antenna.

[0015] The method further involves the acquisition of acceleration measurements by an acceleration sensor on a component of a moving rail vehicle. One or more acceleration measurements can be acquired. The acquisition of acceleration measurements can be carried out with at least one acceleration sensor. The acceleration sensor can be located on a wheel or on another component of a rail vehicle, such as a train. The sensor can be battery-operated. Acquired acceleration measurements can be transmitted wirelessly from the acceleration sensor to another device. The acceleration sensor for acquiring acceleration measurements can be located on only one rail vehicle.Alternatively, several different rail vehicles can be equipped with acceleration sensors to record acceleration measurements. When recording acceleration measurements, acceleration and, alternatively or additionally, vibration at the wheel of the rail vehicle can be detected by the acceleration sensor. Since the wheel travels or rolls on the track, an acceleration measurement can be recorded for that section of track. Acceleration measurements can be recorded specifically for individual track sections.

[0016] In addition to acceleration measurements, corresponding location information in the form of geographic coordinates is recorded, for example, using a GNSS antenna of a global satellite navigation system. This involves recording the geographic coordinates of the moving rail vehicle. These coordinates are acquired using a GNSS at the same times as the acceleration measurements. The recorded geographic coordinates can be stored along with the respective time of acquisition. This allows geographic coordinates, such as a specific location on the track, to be recorded and correlated for each acceleration measurement. In other words, specific recorded acceleration measurements can be assigned to specific locations.

[0017] Furthermore, the procedure includes a step of determining the vehicle orientation of the moving rail vehicle. Vehicle orientation defines the geographical direction in which the front of the rail vehicle points, i.e., the geographical direction in which the front and rear of the vehicle are aligned. Rail vehicles are frequently designed as bidirectional vehicles, so instead of vehicle front and rear, one can also speak of first and second vehicle fronts.

[0018] A further step in the process involves determining the heading of the moving rail vehicle. The heading is the direction in which the rail vehicle is currently moving. For a rail vehicle, a distinction is made between forward and reverse headings, or, in the case of a bidirectional vehicle, between a primary and a secondary direction of travel. When a gateway is permanently installed in the rail vehicle, determining the vehicle orientation and heading can refer to the gateway's orientation and heading, since the orientations and headings of the gateway and the rail vehicle are fixed relative to each other. To determine the direction of travel, it can be calculated from at least two consecutive positions of the rail vehicle, particularly in the form of a heading angle.The vehicle's heading angle, relative to north (0°), can be specified for each timestamp. This heading angle allows the acceleration measurements to be evaluated in such a way that two opposing directions of travel can be distinguished.

[0019] The rail vehicle can have multiple acceleration sensors, each of which is communicatively connected to the gateway and integrated into the process. A further step involves transmitting the recorded acceleration measurements, the geographical coordinates, the vehicle orientation, and the heading to an evaluation unit. The evaluation unit can be at least partially cloud-based and connected to the gateway located on the rail vehicle. The evaluation unit can be configured as part of a cloud and a backend. The backend includes, for example, stationary hardware and ZF Friedrichshafen AG File 304961 -DE-NP Friedrichshafen 102024209878.7 2025-07-30

[0020] Software components used to analyze and evaluate the data transmitted by the rail vehicle.

[0021] For data transmission, a communication method based on an industry standard, such as Bluetooth, WLAN (Wireless Local Area Network), or WPAN (Wireless Personal Area Network), can be used. Data transmission between a gateway on the rail vehicle and a server in the aforementioned cloud can, for example, take place via a digital mobile communication system. The gateway can therefore establish a communication link between at least one accelerometer and a server.

[0022] The first transmission of the recorded acceleration measurements can occur via Bluetooth from an accelerometer to the gateway, and a second transmission of the acceleration measurements can occur from the gateway to a server of the evaluation unit via cellular network. A virtual private network can be used for data transmission to ensure secure data transfer.

[0023] The proposed procedure includes a step of combining the acceleration measurements, geographical coordinates, vehicle orientation, and heading. This can be done, for example, in the evaluation unit. Alternatively, the combination of acceleration measurements, geographical coordinates, vehicle orientation, and heading can also take place directly on the rail vehicle, particularly on the gateway. In this alternative implementation of the procedure, the transmission of the recorded acceleration measurements, geographical coordinates, vehicle orientation, and heading to an evaluation unit only occurs after the aforementioned data has been combined. This combining involves matching values ​​and data recorded at the same time or within a specific time period.It can happen that the acceleration measurements were recorded at a higher frequency than the geographical coordinates and the heading. In this case, the geographical coordinates and the heading are interpolated to obtain complete data sets. ZF Friedrichshafen AG File 304961 -DE-NP Friedrichshafen 102024209878.7 2025-07-30.

[0024] A further step involves transforming the geographic coordinates to the position of the accelerometer. The acquired geographic coordinates are referenced to the GNSS antenna. Using the sensor coordinates, the geographic coordinates can be computationally shifted to the sensor's position. This is done by calculating the shift of the coordinates using geometric functions, taking into account the acquired sensor coordinates, the vehicle's orientation, and its heading. Transforming the geographic coordinates determines the exact position of the accelerometer within the geographic coordinate system, allowing the acceleration measurements recorded by the accelerometer to be precisely assigned to a specific geographic location. This, in turn, allows a track condition determined in the next step to also be precisely assigned to a specific geographic location.For a large rail vehicle, the transformation can involve significant distances because the spatial distance between a GNSS antenna and the accelerometer can be very large. For example, a GNSS antenna can be located more than one hundred meters away from an accelerometer if only a single GNSS antenna is provided for a long train. Therefore, a precise spatial correlation of the acceleration measurements and a derived track condition is not possible with conventional methods.

[0025] Finally, the procedure includes determining the track condition at specific geographical coordinates based on the recorded acceleration measurements. For this purpose, the acceleration measurements are evaluated in the evaluation unit. The procedure thus involves determining the condition of a track section based on the recorded acceleration measurements. Limit-based or non-limit-based methods can be used. Various methods for evaluating acceleration measurements are already known, for example, from the aforementioned WO 2023 / 043801 A1. The determined track condition can be displayed on a display device (ZF Friedrichshafen AG File 304961 -DE-NP Friedrichshafen 102024209878.7 2025-07-30). A display device can be located in the rail vehicle and / or at a stationary location.

[0026] In other words, the recorded acceleration measurements are assigned geographic coordinates so that the track condition can be determined at a precisely localized point on the track using the evaluation unit. For this purpose, the geographic coordinates of the GNSS, which are referenced to a GNSS antenna, are shifted to the exact location of the respective acceleration sensor.

[0027] The recorded acceleration measurements and the geographical coordinates can be correlated in a gateway mounted on the rail vehicle and transmitted as a single data set to a stationary computing unit for further use in determining the track condition. The computing unit is part of the evaluation system.

[0028] The steps of the procedure can be triggered by measurement commands or repeated at regular intervals. This allows for the targeted or comprehensive determination of the track condition of multiple track sections within a railway system. For example, it can be determined at a specific time that acceleration values ​​should be recorded again for a particular track section or measurement sector, perhaps to repeatedly determine the condition of that section or sector. Regularly determining the condition of a track section or sector can be particularly useful. Applying the proposed procedure to numerous crossings with one or more rail vehicles can increase the scope, accuracy, and reliability of the determined track conditions.

[0029] The invention further relates to a control device configured to execute the steps of the method described above. Such a control device can be a gateway arranged on the rail vehicle and a ZF Friedrichshafen AG file 304961 -DE-NP Friedrichshafen 102024209878.7 2025-07-30

[0030] The evaluation unit comprises an evaluation device, which in turn includes a processing unit. The merging of acceleration measurements, geographical coordinates, vehicle orientation, and heading into a data set can take place in the aforementioned gateway, whereby the data set is transferred to the processing unit, and a procedure for determining the track condition based on the data set is carried out in the processing unit. The control unit can be configured as a central control unit for coordinating steps on different rail vehicles. The control unit and the at least one rail vehicle can be connected to each other via communication and wirelessly. The control unit can be configured to integrate several rail vehicles of a fleet into the procedure.

[0031] Finally, the invention also includes a condition monitoring system with such a control unit and with a rail vehicle, which has at least one acceleration sensor for acquiring acceleration measurements. The condition monitoring system can include several rail vehicles, each of which has one or more acceleration sensors. The acceleration sensors can, in particular, be arranged on one or more wheels of the respective rail vehicle. The condition monitoring system can be configured to carry out the described method for determining track damage. This allows steps of the method to be coordinated; for example, the steps of acquiring acceleration measurements can be coordinated with the acceleration sensors.

[0032] The condition monitoring system can also be configured to monitor the condition of rail vehicle components, such as the wheels. For example, the same sensors used to acquire measurements can be used to determine the condition of the wheels. A condition monitoring system may already be configured to perform wheel condition monitoring. Through a software update, the system can be expanded, for example, to also monitor the condition of the track (ZF Friedrichshafen AG File 304961 -DE-NP Friedrichshafen 102024209878.7 2025-07-30). For instance, existing condition monitoring systems for monitoring the condition of rail vehicle wheels can be retrofitted and updated to also monitor the condition of the track.

[0033] Brief description of the characters

[0034] Fig. 1 schematically shows a condition monitoring system for determining track damage.

[0035] Fig. 2 schematically shows the components of a condition monitoring system arranged on a rail vehicle with geometric dimensions in a side view.

[0036] Fig. 3 schematically shows the components of a condition monitoring system arranged on a rail vehicle with geometric dimensions in a top view.

[0037] Fig. 4 schematically shows the structure of a control and evaluation unit of a condition monitoring system for determining track damage in a railway track system.

[0038] Fig. 5 schematically shows the steps of a procedure for determining track damage.

[0039] Detailed description of embodiments

[0040] Fig. 1 schematically shows a condition monitoring system 100 for components of a track system 1. The condition monitoring system 100 has a control unit 20. The control unit 20 includes a cloud 8. The control unit 20 is configured to execute steps of the procedure shown schematically in Fig. 5.

[0041] The condition monitoring system 100 also includes a rail vehicle 3.

[0042] Rail vehicle 3 has acceleration sensors 2. ZF Friedrichshafen AG File 304961 -DE-NP Friedrichshafen 102024209878.7 2025-07-30

[0043] Acceleration sensors 2 are arranged on the wheels of the rail vehicle 3 and configured to record acceleration measurements. The rail vehicle 3 has a gateway 4. A Bluetooth antenna 5, a GNSS antenna 6, and an LTE antenna 7 are communicatively connected to the gateway 4. In other embodiments, the aforementioned antennas 5, 6, and 7 can also be part of the gateway 4 or be integrated with the gateway 4 in a single structural unit. The acceleration sensors 2 are communicatively connected to the Bluetooth antenna 5. In the illustrated embodiment, the LTE antenna 7 is communicatively directly connected to an evaluation unit 10 of the control unit 20. In this embodiment, the GNSS antenna 6 is communicatively connected to satellites of a GNSS system. Furthermore, the condition monitoring system 100 has a display device 9 which is communicatively connected to the control device 20.

[0044] Figures 2 and 3 show the spatial arrangement of the components of the condition monitoring system 100 on the rail vehicle 3, with Figure 2 showing the rail vehicle 3 in a side view and Figure 3 showing the rail vehicle 3 in a top view. Figures 2 and 3 also illustrate a relationship to a front 12, i.e., a front end of the rail vehicle 3, as well as to possible directions of travel 15 and 16. The rail vehicle 3 can be moved, on the one hand, so that the front 12 points in a first direction of travel 15, and on the other hand, so that the front 12 points in a second direction of travel 16, which is opposite to the first direction of travel 15. The rail vehicle 3 is designed as a bidirectional vehicle. The rail vehicle 3 has a drive system that is equivalent in both opposite directions of travel 15 and 16.The rail vehicle 3 can be moved in both directions 15 and 16 within the same speed ranges or gear ratios. The vehicle orientation can be indicated by designating one end of the rail vehicle 3 as the front 12. The respective direction 15 or 16 indicates whether the rail vehicle 3 is moving straight ahead on the track 1 with the front 12 leading, or vice versa. ZF Friedrichshafen AG File 304961 -DE-NP Friedrichshafen 102024209878.7 2025-07-30.

[0045] As an example, an acceleration sensor 2 is arranged in the area of ​​a wheel 14 on each wheelset. A gateway 4 is equipped with a GNSS antenna 6 and is arranged in the area of ​​the roof of the rail vehicle 3. The acceleration sensor 2 is communicatively connected to the gateway 4, in this case via a Bluetooth connection. In embodiments of the invention, several acceleration sensors 2 can be arranged on a rail vehicle 3 and communicatively connected to the gateway 4. For example, an acceleration sensor 2 can be arranged on each wheelset or on each wheel 14.

[0046] A Cartesian coordinate system 13 shows the spatial directions x, y, and z. The distances Dx, D yFigures 2 and 3 show that the accelerometer 2 is located a considerable distance from the GNSS antenna 6 on the rail vehicle 3. Therefore, the acceleration measurements recorded by the accelerometer 2 are not taken at the exact location of the GNSS antenna 6 at the same time. A typical commuter train has a carriage length of approximately 25 meters. With the gateway 4 positioned centrally on the rail vehicle 3, the distance between the GNSS antenna 6 and the accelerometer 2 can exceed 10 meters. For a rail vehicle 3 with multiple carriages, this distance can be very large. Consequently, the location of the recorded acceleration measurements can only be determined very imprecisely using the GNSS satellite navigation system.The proposed method provides a remedy here and enables the precise location-based assignment of the recorded acceleration measurements and, consequently, a more accurate localization of damage to the track system 1 .

[0047] Fig. 4 shows elements of the structure of the control device for determining track damage in a track system and the sequence of a corresponding procedure and is explained in more detail in connection with the steps from Fig. 5.

[0048] The steps are shown schematically in Fig. 5. In a first step S1, a rail vehicle 3 is provided with at least one acceleration sensor 2 for recording acceleration measurements and with a GNSS antenna 6 for recording geographical coordinates.

[0049] In step S2, sensor coordinates are read in, describing the position of the accelerometer 2 relative to the GNSS antenna 6. The sensor coordinates can be stored in the gateway 4 or in the evaluation unit 10. For this purpose, the gateway 4 or the evaluation unit 10 can have a data storage device. The sensor coordinates can be stored, in particular, in the form of Cartesian coordinates according to the Cartesian coordinate system 13 described above.

[0050] In a further step S3, acceleration measurements are acquired by the acceleration sensor 2 on a component of the moving rail vehicle 3. This component can be, in particular, a wheel 14 of the rail vehicle 3 or another wheel-adjacent component of the rail vehicle 3, which allows accelerations and vibrations caused by damage to the track system 1 to be detected particularly well. Step S3 takes place while the rail vehicle 3 is in motion and can be coordinated by the control unit 20, which sends measurement commands to the acceleration sensors 2 via the gateway 4.

[0051] In a further step S4, the geographical coordinates of the moving rail vehicle 3 are recorded. These coordinates are acquired using a GNSS at the same time points as the acceleration measurements. Furthermore, in step S5, the orientation of the moving rail vehicle 3 is recorded, and in step S6, its heading is determined. Steps S3, S4, S5, and S6 can all be performed simultaneously or at least together within a limited timeframe.

[0052] The recorded acceleration measurements, geographical coordinates, vehicle orientation, and heading are transmitted in step S7 to an evaluation unit 10, where they are combined in a further step S8. Steps S7 and S8 can also be performed in reverse chronological order, so that the aforementioned data and measurements are first combined, particularly in gateway 4, and then transmitted to the evaluation unit 10.

[0053] In step S9, the geographical coordinates are transformed to the position of accelerometer 2 based on the read sensor coordinates. This is done by calculating and applying a shift of the coordinates using geometric functions, taking into account the read sensor coordinates, the vehicle orientation, and the heading.

[0054] Finally, in step S10, the acceleration measurements are evaluated in the evaluation unit 10 and a track condition is determined at certain geographical coordinates.

[0055] The merging of acceleration measurements, geographical coordinates, vehicle orientation, and heading into a single data set can be performed either entirely or partially within Gateway 4. In this case, the data set, including the already merged data, is then transferred to Computing Unit 11.

[0056] ZF Friedrichshafen AG File 304961 -DE-NP Friedrichshafen 102024209878.7 2025-07-30

[0057] Reference mark

[0058] 1 track system

[0059] 2 Accelerometers

[0060] 3 Rail vehicle

[0061] 4 Gateway

[0062] 5 Bluetooth antenna

[0063] 6 GNSS antenna

[0064] 7 Mobile phone antenna

[0065] 8 Cloud

[0066] 9 Display setup

[0067] 10 Evaluation unit

[0068] 11 Calculation unit

[0069] 12 Front

[0070] 13 Coordinate system

[0071] 14-inch wheel

[0072] 15 Direction of travel

[0073] 16 Direction of travel

[0074] 20 Control unit

[0075] 100 Condition monitoring system

[0076] S1 - S10 Steps of the procedure

Claims

ZF Friedrichshafen AG File 304961 -DE-NP Friedrichshafen 102024209878.7 2025-07-30 (new) patent claims 1. Method for determining track damage of a railway track system (1), comprising the steps: • Provision (S1 ) of a rail vehicle (3) with at least one Accelerometer (2) for recording acceleration measurements and with a GNSS antenna (6) for recording geographic coordinates, • Reading (S2) sensor coordinates that define the position of the Describe the acceleration sensor (2) in relation to the GNSS antenna (6), • Acquisition (S3) of acceleration measurements by the Acceleration sensor (2) on a component of the moving rail vehicle (3), • Recording (S4) geographical coordinates of the moving rail vehicle (3) • Detecting (S5) a vehicle orientation of the moving rail vehicle (3), • Detecting (S6) the direction of travel of the moving rail vehicle (3) • Transfer (S7) the recorded acceleration measurements, the geographical Coordinates, vehicle orientation and course direction to an evaluation unit (10), • Combining (S8) the acceleration measurements, the geographical Coordinates, vehicle orientation and course direction, • Transform (S9) the geographic coordinates to the position of the accelerometer (2) based on the read sensor coordinates and • Evaluation (S10) of the acceleration measurements in the evaluation unit (10) and determination of a track condition at specific geographical coordinates.

2. Method according to claim 1, characterized in that the acceleration measurements and the geographical coordinates are assigned to each other in a gateway (4) arranged on the rail vehicle (3) and are each transmitted as a related data set to a stationary computing unit (11). ZF Friedrichshafen AG File 304961 -DE-NP Friedrichshafen 102024209878.7 2025-07-30 3. Method according to claim 1 or 2, characterized in that the transformation is carried out using geometric functions.

4. Method according to one of the preceding claims, characterized in that the steps of the method are triggered by measurement commands or are repeated at regular intervals.

5. Control device (20) which is configured to perform the steps of a method according to the preceding claims.

6. Control device (20) according to claim 5, comprising a gateway (4) arranged on the rail vehicle (3) and an evaluation device (10), with a computing unit (11), wherein the acceleration measurement values, the geographical coordinates, the vehicle orientation and the heading are combined into a data set in the gateway (4), wherein the data set is transferred to the computing unit (11), and wherein a method for determining the track condition on the basis of the data set is carried out in the computing unit (11).

7. Condition monitoring system (100) with a control device (20) according to claim 5 and a rail vehicle (3) which has at least one acceleration sensor (2) for recording acceleration measurements.

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