WO2023227394A1

WO2023227394A1 - Rail vehicle and method for capturing track position data

Info

Publication number: WO2023227394A1
Application number: PCT/EP2023/062876
Authority: WO
Inventors: David BUCHBAUER; Florian Auer; Christian OBEXER
Original assignee: Plasser & Theurer, Export von Bahnbaumaschinen, Gesellschaft m.b.H.
Priority date: 2022-05-24
Filing date: 2023-05-15
Publication date: 2023-11-30
Also published as: AT17971U1

Abstract

The invention relates to a rail vehicle (1) having a vehicle frame (2) which is movable on rails (5) of a track (4) in a manner supported on bogies (3), comprising a measurement platform (9) with a first inertial measurement system (13) for capturing track position data. The same measurement platform (9) has an associated second inertial measurement system (13) for measuring a movement of the measurement platform (9), the two inertial measurement systems (13) being coupled to a computer (17) and an algorithm for evaluating captured track position data being set up in the computer (17). Additional measured values are therefore available for calculating the track position data.

Description

Rail vehicle and method for recording track position data

Technical area

[01] The invention relates to a rail vehicle with a vehicle frame that can be moved on rails of a track while supported on rail chassis, comprising a measuring platform with a first inertial measuring system for recording first track position data. The invention further relates to a method for operating such a rail vehicle.

State of the art

[02] A rail vehicle with an inertial measuring system for recording track position data is known, for example, from AT 523627 A4. An inertial measurement unit (IMU) is used to record measurement data from a trajectory during a measurement run. Relative movements of the inertial measuring unit relative to the track are compensated for using position measuring devices. As a result, the inertial measuring system provides actual track position data that is used to calculate a target geometry of the track.

[03] From AT 520526 A4 a rail vehicle is known in which a first measuring platform is arranged on a rail chassis. A track course is recorded using an inertial measuring system attached to the first measuring platform. A second measuring platform with a second inertial measuring system and with a sensor device for detecting surface points of a track section is arranged on the car body of the rail vehicle. With the second inertial measuring system, a movement of the sensor device in three-dimensional space is recorded.

Presentation of the invention

[04] The invention is based on the object of improving a rail vehicle of the type mentioned in such a way that the track position data can be recorded with higher quality, in particular with higher quality Process reliability is feasible. A corresponding procedure should also be specified.

[05] According to the invention, these tasks are solved by the features of independent claims 1 and 9. Dependent claims specify advantageous embodiments of the invention.

[06] The same measuring platform is assigned a second inertial measuring system for measuring a movement of the measuring platform, both inertial measuring systems being coupled to a computer and an algorithm for evaluating recorded track position data being set up in the computer. Specifically, in every inertial measuring system, an inertial measuring unit (IMU) records the movement of the measuring platform in free space with three acceleration sensors and three gyrocompasses. The measuring platform is a rigid component of the rail vehicle. Due to the fixed arrangement of the inertial measuring units of both inertial measuring systems on the same rigid measuring platform, the movement of the measuring platform is recorded twice. This means that additional measured values are available for recording or calculating track position data. On the one hand, the recorded measurement data can be used for mutual checking. On the other hand, if the inertial measuring units are arranged accordingly, additional information can be obtained from the resulting trajectories for calculating the track position data. Precise track position data results directly from the respective trajectory when the measuring platform is guided along the track with the flanged wheels pressed against a rail. Otherwise, the respective trajectory is at least close to the course of the track, with deviations optionally being able to be recorded and compensated for. The acquisition of approximate track position data is sufficient for some applications.

[07] In an advantageous development, each inertial measuring system is set up to separately record track position data. Both inertial measuring systems measure the track geometry in accordance with regulations, for example in accordance with the EN 13848-2 standard. With the two inertial measuring systems integrated into an overall system, the track position is recorded redundantly. The entire system checks itself completely autonomously and repeatedly. Measuring errors are automatically detected and corrected immediately. To this The redundantly available track position data leads to greater process reliability.

[08] Preferably, the measuring platform is arranged on one of the rail chassis, in particular as a measuring frame connected to wheel axles. This allows relative movements of the measuring platform relative to the track to be minimized. With a measuring frame connected to the wheel axles, only pendulum movements of the wheels relative to the rails need to be taken into account. Apart from that, the trajectories recorded using the inertial measuring units correspond to the course of the track.

[09] In an advantageous variant, at least one track measuring unit for detecting the position of the measuring platform relative to at least one rail of the track is arranged on the measuring platform. This means that any relative movements between the measuring platform and the rail in the transverse direction to the track axis are recorded. For example, the track measuring unit is designed as a light section sensor and is directed towards the inner edge of the rail head. The exact course of this inner edge of the rail can then be derived from the trajectories recorded by the two inertial measuring units.

[10] A further improvement enables the exact detection of both rail routes by arranging a front track width measuring system and a rear track width measuring system spaced apart from it in the longitudinal direction of the vehicle on the measuring platform. This allows the position of the measuring platform to be determined when stationary, at low and at high speeds, relative to both rails of the track. In addition, the track width can be measured separately with each of the track width measuring systems.

[11] Advantageously, different algorithms for processing movement data are set up in the first inertial measuring system and in the second inertial measuring system. This increases functional safety, resulting in higher safety integrity levels (SIL). High overall accuracy occurs when the results obtained with both algorithms lie within a narrow tolerance range. Corresponding accuracy specifications are defined in the EN 13848-2 standard. [12] Furthermore, the functional safety is increased if the first inertial measuring system and the second inertial measuring system include different hardware components, in particular different inertial measuring units. This ensures that any sources of errors inherent in the system can be identified and corrected immediately.

[13] To record the distance traveled by the rail vehicle, an odometer is advantageously arranged on a wheel axle. The data recorded using the inertial measuring systems is evaluated together with the measured path. Furthermore, several track width measuring systems arranged one behind the other can be used for distance measurement. Minor changes in the course of the track width are used. Every point on the track has a characteristic track width in its surroundings. The measurement of the track width can therefore be used to determine the corresponding location on the track and subsequently the distance traveled. This use of the track width measuring systems can also be used to check the path measured using the odometer. This in turn increases functional safety because the route is recorded using two independent systems that function physically differently.

[14] In the method according to the invention for operating the rail vehicle described, a movement of the measuring platform is measured using both inertial measuring systems, track position data being derived from the measured movement and the track position data being evaluated using the algorithm set up in the computer. Measuring motion twice on the same measuring platform increases overall accuracy and process reliability.

[15] Advantageously, first track position data is recorded by means of the first inertial measuring system and second track position data is recorded by means of the second inertial measuring system, in particular longitudinal height data, arrow height data, torsion data, cant data and track width data being recorded as respective track position data. In this embodiment of the invention, each of the two inertial measuring systems initially records the track position data regardless of the other inertial measuring system. Only then is a joint evaluation carried out using the computer.

[16] In a preferred development, at least a selection of first track position data is compared with a corresponding selection of second track position data using the algorithm, with an error message being generated if a difference between the compared track position data reaches a tolerance limit. This ongoing integrity check achieves a high level of functional safety.

[17] It is advantageous to register the error message in a digital measurement protocol. Such a measurement protocol ensures that the measurements carried out with the inertial measuring systems remain traceable. Digital error registration enables automatic further processing of the measurement results, whereby recurring errors can be recognized and compensated for using a machine learning algorithm.

[18] In a further improvement of the method, position data of the measuring platform relative to at least one rail of the track is recorded by means of a track measuring unit arranged on the measuring platform. This means that relative movements of the measuring platform relative to the rail in the transverse direction of the track can be easily compensated for.

[19] In a preferred development, the first track position data are calculated on the basis of the position data by means of an evaluation device assigned to the first inertial measuring system and the second track position data are calculated by means of an evaluation device assigned to the second inertial measuring system. Each inertial measuring system is therefore set up to separately record the track position data, with relative movements of the measuring platform compared to the track being compensated for with the same position data.

[20] Advantageously, the position of the measuring platform is recorded by means of a front track width measuring system and a rear track width measuring system, with track width data recorded thereby being compared with track width data from a further track width measuring system arranged on the rail vehicle. In addition to the exact position detection of the measuring platform, this process improvement enables redundant path detection based on the characteristic track width. This increases measurement accuracy and process reliability.

Brief description of the drawings

[21] The invention is explained below in an exemplary manner with reference to the attached figures. It shows in a schematic representation:

Fig. 1 rail vehicle on a track in side view

Fig. 2 rail vehicle on a track in an oblique view

Fig. 3 Cross section of a rail vehicle on a track Fig. 4 Track measurement with two track width measuring systems

Description of the embodiments

[22] The rail vehicle 1 shown in Fig. 1 comprises a vehicle frame 2, which can be moved on rail chassis 3 on a track 4. The track 4 comprises two rails 5, which are fastened to sleepers 7 stored in a ballast bed 6. The invention also relates to a slab track, not shown, in which the rails 5 are attached to a solid concrete superstructure. The rail vehicle 1 is, for example, a measuring vehicle or a track-laying machine with a work unit 8 for track processing.

[23] The rail vehicle 1 shown includes several measuring platforms 9 that are movable relative to one another. For example, an optical measuring system 10 for detecting surface points of the track 4 is set up on one of the measuring platforms 9 in the front area. Between the rail chassis 3 there is a further measuring platform 9 with track width measuring systems 11 attached thereto, each of which includes track measuring units 12 directed towards the rails 5. The respective track measuring unit 12 is, for example, a light section sensor that detects the position of the measuring platform 9 relative to the associated rail 5.

[24] In addition, a measuring platform 9 designed as a measuring frame is arranged on one of the rail carriages 3. Relative movements between this measuring platform 9 and the other measuring platforms 9 result from the suspension, steering and inclination of the rail chassis 3 relative to the vehicle frame 2. A first and a second inertial measuring system 13 are assigned to the rigid measuring frame. At least the inertial measuring units 14 of the two inertial measuring systems 13 are fixed in their position relative to one another on the measuring platform 9. The term inertial measuring unit (IMU) refers to the actual measuring instrument for measuring angular rate and acceleration. The respective inertial measuring system 13 is also able to process correction algorithms and determine the position. The measuring instrument and a microcontroller 20 are usually housed in a common housing. However, the components can also be divided into several housings.

[25] A trajectory 15 of the assigned inertial measuring unit 14 can be derived from the movement data recorded by means of the respective inertial measuring system 13. The reference system is usually a coordinate system with the origin at the starting position of a measurement run. As soon as the rail vehicle 1 starts moving, 15 position points are recorded along the two trajectories, the coordinates of which are subsequently available for evaluation.

[26] The distance traveled is recorded, for example, using an odometer 16. Alternatively or additionally, the track width measuring systems 11 are used for path detection. While the rail vehicle 1 is traveling forward, each track width measuring system 11 records a course of the track width g over a travel time t, as shown in FIG. 4. Because both track width measuring systems 11 measure the same track 4 immediately one behind the other, two approximately identical track width profiles result with a time offset At. This time offset At is evaluated, with the current driving speed and the route traveled being able to be determined with a fixed distance a between the track width measuring systems 9. In this way, the track width measuring systems 11 are also used for path measurement in addition to position and track width measurement.

[27] In addition, the track width measurement carried out several times increases process reliability. For this purpose, the track width measuring systems 11 are coupled to a computer 17. The computer 17 continuously compares the input parameters in the form of the track tracks. Be compared For example, the measurement results of a first group of track width measuring systems 11 arranged on the vehicle frame 2 with the measurement results of a second group of track width measuring systems 11 arranged on the rail chassis 3. The latter are coupled to the inertial measuring systems 13. For example, an average value is formed from the measurement results of the first group, which is continuously compared with a current measured value of the second group via a known longitudinal offset b. If the deviations are too great, an error message is generated.

[28] Both inertial measuring systems 13 are also coupled to the computer 17.

Using an algorithm set up in the computer 17, the recorded track position data is evaluated, with the integrity of the data also being checked. In the simplest case, the data recorded using the inertial measuring systems 13 are continuously compared. As soon as a difference reaches a tolerance limit, an error message is generated. This makes sense if the inertial measuring units 14 are arranged directly next to one another on the measuring platform 9. It can then be assumed that the same movement data is recorded synchronously in error-free operation. Such an arrangement is shown in FIG. 2, with a car body of the rail vehicle 1 being shown lifted off the rail chassis 3 for better visibility of the individual components.

[29] Advantageously, the two inertial measuring systems 13 differ in the installed hardware components. In order to further increase process reliability, the two inertial measuring systems 13 also differ in the algorithms and filters set up for processing the movement data. The use of different systems to record and process movement data increases the security integrity level. This requirement is met, for example, by using inertial measuring systems from 13 different manufacturers.

[30] There is also the possibility of automatically calibrating the two inertial measuring systems 13 by continuously coordinating the measurement results with one another. A drift that usually occurs with inertial measuring units 14 can thus be compensated for. [31] With a spaced arrangement of the inertial measuring units 14 on the measuring platform 9, additional information is obtained. In the example in FIG. 1, the first inertial measuring unit 14 is arranged on a front crossbar of the measuring frame and the second inertial measuring unit 14 is arranged on a rear crossbar of the measuring frame. In this way, the movement of the measuring platform 9 in space is recorded at different points. The forward movement of the rail vehicle 1 can be derived from the resulting movement data.

[32] The position of the measuring frame relative to the rails 5 is determined with the track width measuring systems 11 arranged at the front and rear of the measuring frame. 3 shows one of these track width measuring systems 11 with two track measuring units 12. In each track measuring unit 12, a laser source 18 projects a fan of light onto the associated rail 5. The resulting projection on the rail 5 is recorded by a camera 19 and evaluated in a microcontroller 20. In this way, the position of the track measuring unit 12 relative to the associated rail 5 is recorded. All four track measuring units 12 arranged on the measuring frame provide position data of the measuring frame relative to the rails 5.

[33] In an evaluation device 21, the position data recorded by the track width measuring systems 11 are used to draw conclusions about the track position from the respective trajectory 15. The coordinates of the respective trajectory 15 are transformed onto the respective rail 5 via the known geometric arrangement of the inertial measuring units 14 and the track measuring units 12 relative to one another. This subsequently results in the relevant track parameters, in particular the track width, the direction or arrow height, the longitudinal height, the elevation and the torsion of the track 4. Advantageously, each inertial measuring system 13 is assigned its own evaluation device 21. Subsequently, the track position data determined twice is evaluated in the computer 17 and its integrity is checked.

[34] By merging the measurement data, the overall accuracy is increased. Errors are recognized immediately and taken into account when further processing the track position data. This is done, for example, by stochastic comparisons of the track parameters determined with the different individual measuring systems. Using statistical evaluations, measurement inaccuracies can be compensated for and specific measurement errors can be hidden. The EN 13848-2 standard defines the required accuracy. For each individual measuring system, 95% of the measurement results must be within the specified tolerance. The redundancy of the individual measuring systems according to the invention results in a higher overall accuracy, with up to 99% of the combined measurement results being within tolerance.

Claims

Patent claims

1. Rail vehicle (1) with a vehicle frame (2), which is supported on rail chassis (3) and can be moved on rails (5) of a track (4), comprising a measuring platform (9) with a first inertial measuring system (13) for recording track position data , characterized in that the same measuring platform (9) is assigned a second inertial measuring system (13) for measuring a movement of the measuring platform (9), that both inertial measuring systems (13) are coupled to a computer (17) and that in the computer (17) an algorithm is set up to evaluate recorded track position data.

2. Rail vehicle (1) according to claim 1, characterized in that each inertial measuring system (13) is set up to separately record track position data.

3. Rail vehicle (1) according to claim 1 or 2, characterized in that the measuring platform (9) is arranged on one of the rail chassis (3), in particular as a measuring frame connected to wheel axles.

4. Rail vehicle (1) according to one of claims 1 to 3, characterized in that on the measuring platform (9) there is at least one track measuring unit (12) for detecting the position of the measuring platform (9) relative to at least one rail (5) of the track (4) is arranged.

5. Rail vehicle (1) according to one of claims 1 to 4, characterized in that a front track width measuring system (11) and a rear track width measuring system (11) spaced apart from it in the longitudinal direction of the vehicle are arranged on the measuring platform (9).

6. Rail vehicle (1) according to one of claims 1 to 5, characterized in that different algorithms for processing movement data are set up in the first inertial measuring system (13) and in the second inertial measuring system (13).

7. Rail vehicle (1) according to one of claims 1 to 6, characterized in that the first inertial measuring system (13) and the second inertial measuring system (13) comprise different hardware components, in particular different inertial measuring units (14).

8. Rail vehicle (1) according to one of claims 1 to 7, characterized in that an odometer (16) for detecting a path is arranged on a wheel axle of the rail vehicle (3).

9. Method for operating a rail vehicle (1) according to one of claims 1 to 8, characterized in that a movement of the measuring platform (9) is measured by means of both inertial measuring systems (13), that track position data is derived from the measured movement and that the track position data is evaluated using the algorithm set up in the computer (17).

10. The method according to claim 9, characterized in that first track position data is recorded by means of the first inertial measuring system (13) and second track position data is recorded by means of the second inertial measuring system (13) and in particular longitudinal height data, arrow height data, torsion data, cant data and track width data are recorded as respective track position data .

11. The method according to claim 10, characterized in that by means of the algorithm at least a selection of first track position data is compared with a corresponding selection of second track position data and that an error message is generated when a difference between the compared track position data reaches a tolerance limit.

12. The method according to claim 11, characterized in that the error message is registered in a digital measurement protocol.

13. The method according to one of claims 9 to 12, characterized in that by means of a track measuring unit (12) arranged on the measuring platform (9). Position data of the measuring platform (9) relative to at least one rail (5) of the track (4) are recorded.

14. The method according to claim 13, characterized in that the first track position data are calculated on the basis of the position data by means of an evaluation device (21) assigned to the first inertial measuring system (13) and the second ones by means of an evaluation device (21) assigned to the second inertial measuring system (13). Track position data can be calculated.

15. The method according to one of claims 9 to 14, characterized in that the position of the measuring platform (9) is recorded by means of a front track width measuring system (11) and a rear track width measuring system (11) and that the track width data recorded thereby is combined with track width data from another on the rail vehicle (1) arranged track width measuring system (11).