Marking element and method for identifying a point on a track

Abstract

The invention relates to a marking element (11) for marking and identifying a point (12) on a track (1), comprising a securing means for securing to a rail (5) of the track (1) and comprising an identification means. The marking element (11) is a sheet metal part, which has an elastic clip (19) as a securing means for clipping to a rail foot (18), and an identification code in the form of a three-dimensional structure (20) as an identification means. A marking element (11) of this type is simply constructed and is recognised by different measuring systems due to the three-dimensional structure (20) of the identification code.

Description

Description Marking element and method for identifying a location on a track Technical area

[0001] The invention relates to a marking element for marking and identifying a location on a track, comprising a fastening means for attachment to a rail of the track and an identification means. Furthermore, the invention relates to a method for identifying a location on a track using a rail vehicle, which comprises an optical and / or distance-measuring sensor directed toward the track. State of the art

[0002] A track for rail vehicles includes tracks, switches, switch connections, and crossings, as well as overhead lines and other track-related facilities. Due to use and weather influences, such a track is subject to continuous wear and tear, necessitating regular maintenance. This is based on actual track data, which is determined using various well-known measuring methods and equipment.

[0003] For example, AT 518692 A1 describes a system and method for maintaining a track for rail vehicles. In this system, objects on the track are detected using multiple sensors. A computer then identifies the objects and assigns them to a respective object group. Object data, along with position data, is stored in a database and used for planning and implementing maintenance measures.

[0004] DE 10 2011 017 134 A1 discloses an arrangement for marking and measuring track sections for maintenance purposes. A sensor unit is used to contactlessly record measuring points located next to a rail in order to precisely position wear-prone track sections. Two qualitatively different measuring principles are used for optical detection and for identification of the respective measuring point. Description of the invention

[0005] The invention is based on the object of providing a marking element of the type mentioned above that is easy to manufacture and robust. Furthermore, the marking element should be detectable using various sensors and can be arranged on the track in a space-saving manner. A further object is to provide an improved method for marking and identifying a location on a track.

[0006] According to the invention, these objects are achieved by the features of independent claims 1 and 8. Dependent claims specify advantageous embodiments of the invention.

[0007] The marking element is a sheet metal part that features an elastic clamp for clamping to a rail foot as a fastening means and an identification code in the form of a three-dimensional structure as an identification means. Such a marking element is simply constructed and is recognized by various measuring systems due to the three-dimensional structure of the identification code. In addition to optical sensors, distance-measuring sensors are also suitable for detecting the identification code. The simple design, without electronic components and without color markings, enables a service life of decades. On the one hand, the clamping to the rail foot is robust against acting forces, such as those caused by vibrations and turbulence from a rail vehicle traveling at high speed. On the other hand, the arrangement is space-saving and does not impede track maintenance measures.This includes tamping work with tamping picks that are inserted into a ballast bed or rail processing such as grinding or milling.

[0008] In a particularly simple version, the bleaching part is designed as a one-piece curved bleaching strip. Such a marking element is It can be manufactured in large quantities and can be installed at many locations along the track. The large number of corresponding marking elements within a rail network enables particularly efficient track mapping for maintenance planning and implementation.

[0009] In a further improvement, a clip-shaped sheet metal section forms the elastic clamp. This clip-shaped sheet metal section has opposing, upwardly bent ends, with the distance between the upwardly bent ends being adapted to a predetermined width range of a rail foot. The upwardly bent ends are elastically pressed outward during an assembly process and, in the clamped position, enclose the rail foot.

[0010] The detectability of the marking element using various sensor systems depends on the installation position. In a preferred embodiment, an identification section of the sheet metal part forms an angle between 5° and 85°, in particular between 15° and 75°, with a horizontal plane. An upper end of the identification section points toward the rail head. An optical and / or distance-measuring sensor system directed toward the respective rail thus also detects the identification section of the marking element.

[0011] Preferably, elements of the identification code are arranged as openings and / or depressions and / or elevations within the identification section. The resulting three-dimensional structure is particularly easily recognizable for optical and / or distance-measuring sensors because the openings, in particular, have a high contrast and distance from the surrounding surface of the sheet metal part. In the case of depressions and elevations, optical detection is improved by obliquely incident light with corresponding shadow formation. The geometric shape of the respective opening, elevation, or depression and the arrangement of these elements relative to one another represent the identification code assigned to the corresponding marking element.

[0012] In an improved version, the elements of the identification code are bounded by an envelope in the form of a geometric figure with a vertex that, when the marking element is installed, points toward a position point on the track axis. For example, the elements of the identification code on the surface of the identification section are bounded by an envelope in the shape of a triangle. During a track measurement, a vertex of the triangle serves as a measurement point for determining the position of the marking element. In other versions, lines of symmetry or intersection points are used to determine measurement points.

[0013] A further advantage in detecting the marking element results from a further development using a barcode as the identification code, whereby the bars of this barcode are aligned approximately parallel to the longitudinal direction of the track when the marking element is installed. This variant simplifies detection using a line scan camera or a line-intersection sensor. When traveling along the track with a corresponding detection device, a line scan is sufficient to capture the information of the identification code. The length of the barcode bars and the travel speed of the detection device determine the required capture rate.

[0014] In the method according to the invention for identifying a point on the track using a rail vehicle comprising an optical and / or distance-measuring sensor directed at the track, a marking element according to the invention clamped onto a rail of the track is detected by the optical and / or distance-measuring sensor. In this way, the arrangement of a simple optical and / or distance-measuring sensor and a corresponding evaluation device is sufficient to detect the three-dimensional structure of the marking element. If necessary, optical and / or distance-measuring sensors already installed on a rail vehicle can be used to identify a location on the track.

[0015] In a further development of the method, a captured image of the three-dimensional structure arranged on the marking element is evaluated in a computer using a pattern recognition algorithm. Such a method enables the automated identification of points on a track marked by the marking element. For example, a measuring vehicle equipped with optical sensors travels along a track and stores the captured image data in a storage unit. The computer accesses this image data in real time or with a time delay and automatically searches for images with an identification code. As soon as the algorithm implemented in the computer recognizes such an image, the corresponding identification code is output and further processed.

[0016] Advantageously, the position of the rail vehicle is recorded in an associated reference system at the same time as the marking element is detected. This provides position data that can be assigned to the respective identified identification code. The respective identification code and the associated location data are then stored in a database for further processing. The stored data is used for track maintenance planning and maintenance execution. Short description of the drawings

[0017] The invention is explained below by way of example with reference to the accompanying figures. They show schematically: Fig. 1 Track cross-section with a rail vehicle comprising optical and / or distance measuring sensors; Fig. 2 Cross section of a marking element; Fig. 3a Cross section of a rail with marking element; Fig. 3b Oblique view of the rail and the marking element shown in Fig. 3a; Fig. 4 Marking element with alternative identification section; Fig. 5 Track cross-section with a tamping machine; Fig. 6 composite marking element; Fig. 7 one-piece marking element; Fig. 8 Marking element with extended clamping area of ​​the elastic clamp; Fig. 9 captured view of the track with marking elements. Description of the embodiments

[0018] The track 1 shown in Fig. 1 is a ballasted track with sleepers 3 supported in a ballast bed 2. Two rails 5 are fastened to the sleepers 3 by means of rail fastenings 4. A rail vehicle 6 travels along the track 1, with wheels 7 of a rail bogie 8 guided along the rails 5. The rail bogie 8 comprises a measuring frame 9 on which optical and / or distance-measuring sensors 10 are arranged. In the example shown, marking elements 11, designed as sheet metal parts, are clamped onto each rail 5 of the track 1.

[0019] The respective marking element 11 marks a location 12 on track 1 in order to subsequently plan and carry out maintenance measures on track 1. Such locations 12 on track 1 indicate, for example, the positions of elements of a switch or the positions of damaged areas on track 1 in an assigned reference system xyz.

[0020] The optical and / or distance-measuring sensors 10 arranged on the rail vehicle 6 are components of a detection system comprising a position detection device 13 and an evaluation device 14. The position detection device 13 is, for example, an inertial navigation system (INS) for detecting a current position of the measuring frame 9 in space, coupled with an odometer for path detection. The evaluation device 14 comprises a Computer 15, in which a pattern recognition algorithm is implemented. Computer 15 is part of a data network with a connection to a database. Components of the data network are located on the rail vehicle 6 and / or in a remote data center.

[0021] A video camera, a line scan camera, a line section sensor, or a radar sensor, for example, is used as the optical and / or distance-measuring sensor 10. This captures image data and / or distance data, which are subsequently evaluated by the evaluation device 14. In the example shown, three optical and / or distance-measuring sensors 10 are directed at each rail 5 to detect the rail head 16, the rail web 17, and the rail foot 18 of the associated rail 5, as well as the sleepers 3 with the rail fastenings 4. The result of the detection is shown in Fig. 9.

[0022] The respective marking element 11 is clamped to the rail foot 18 of the respective rail 5 by means of an elastic clamp 19. As an identification means, the marking element 11 comprises an identification code in the form of a three-dimensional structure 20. This three-dimensional structure 20 can be detected by the optical and / or distance-measuring sensors 10 arranged on the rail vehicle 6.

[0023] Fig. 2 shows a preferred embodiment of the marking element 11. This marking element 11 is manufactured as a one-piece, bent sheet metal strip. The sheet metal strip has a clasp-shaped sheet metal section 21 as an elastic clamp 19 and an identification section 22 with the three-dimensional structure 20. The three-dimensional structure 20 is composed of elements of the identification code in the form of openings 23 and / or depressions 24 and / or elevations 25. Openings 23, in particular, are very clearly detectable by the optical and / or distance-measuring sensors 10, regardless of the lighting conditions.

[0024] So that the marking element 11 is, on the one hand, easily recognizable and, on the other hand, does not represent an obstacle when working on the track 1, the identification section 22 forms an angle a of between 5° and 85°, in particular between 15° and 75°, with a horizontal plane 26. In Fig. 2, the angle a is 52°. An inner width b of the clip-shaped sheet metal section 21 is adapted to the width of the respective rail foot 18. By means of a curved or multiply bent design of the clip-shaped sheet metal section 21 and by means of the elastic deformability, the marking element 11 can be clamped to rails 5 with different rail foot widths (Fig. 8). The free end 27 of the clip-shaped sheet metal section 21 is preferably bent outwards to facilitate attachment to the rail foot 18.

[0025] Figures 3a and 3b show the marking element 11 clamped onto the rail 5. Fig. 3b shows the arrangement in the viewing direction 28 shown in Fig. 3a with the identification section 22 without distortion. A barcode 29 with black-illustrated openings 23 is arranged on the identification section 22 as an identification code. The bars of the barcode 29 in the form of openings 23 are aligned parallel to a longitudinal track direction 30. Due to this alignment, a line recording 31 transverse to the longitudinal track direction 30 is sufficient to capture the identification code. For example, for line-section sensors or line-scan cameras, a capture rate is specified which, depending on the travel speed of the rail vehicle 6, results in a capture distance (e.g., 10 cm) that is shorter than the length of the openings 23 (e.g., 20 cm).

[0026] Fig. 4 shows a barcode 29 in the shape of a triangle. The bars of the barcode 29 are arranged next to each other with decreasing length, so that an envelope 32 of the bar ends has the shape of a triangle. A vertex 33 of this triangle defines the exact position of the marking element 11. For example, the position of the marking element 11 is defined as path x. 17 x2along a track axis 34 (kilometering). Alternatively, the position of the marking element 11 is defined by a center line 35 of the sheet metal strip (Fig. 9). The center line 35 is detected, for example, based on pattern recognition of the outline of the marking element 11.

[0027] In a variant not shown, a QR code is used as the identification code, whereby care must be taken to ensure that the optical and / or distance-measuring sensors 10 detect the entire area of ​​the identification section 22. In addition, it is advisable to supplement the identification code with stamped letters and / or numbers 36 so that the identification code is readable by a person working on track 1.

[0028] Fig. 5 shows that the arrangement of the marking element 11 according to the invention does not represent an obstacle to the processing of the track 1. In the example shown, the track 1 is tamped using a tamping machine 37. Tamping picks 38 of a tamping unit 39 penetrate into the ballast bed 2 on both sides of the respective sleeper 3. By clamping the respective marking element 11 to the associated rail foot 18 and the oblique orientation of the identification section 22, there is sufficient distance from the tamping picks 38 that penetrate into the ballast bed 2 next to the rails 5. Dashed lines show the tamping picks 38 in the lowered position. The marking elements 11 also do not represent any obstacles for the grinding or milling of the respective rail head 16.

[0029] Figures 6 to 8 show further embodiments of the marking element 11. The marking element 11 in Fig. 6 is made of two bent sheet metal strips. One sheet metal strip forms the elastic clamp 19, and the second sheet metal strip comprises the identification section 22. Both sheet metal strips are joined by spot welding, gluing, or another joining method. The angle a between the horizontal plane 26 and the identification section 22 is 45° here. The marking element 11 is particularly space-saving and easy to manufacture. in Fig. 7 with an angle a equal to 82°. All variants of the marking element 11 can be combined with a curved, clamp-shaped sheet metal section 21 to enable clamping to rails 5 with rail feet 18 of different widths (Fig. 8). To increase elastic deformability, multiple bending of this clamp-shaped sheet metal section 21 is advisable to provide a larger clamping area.

[0030] A view of track 1 captured by the optical and / or distance-measuring sensors 10 in Fig. 1 is shown in Fig. 9. For verification purposes, a corresponding image is displayed, for example, to an operator of the rail vehicle 6 on a computer screen 40. Synchronously captured images 41 of the individual optical and / or distance-measuring sensors 10 are combined to form a common image of track 1. The oblique viewing angles of the sensors 10 positioned laterally above the respective rail 5 result in a distorted top view of track 1, with the obliquely arranged identification sections 22 of the marking elements 11 appearing without distortion. Errors in the capture of the respective identification code are thus avoided.

[0031] The position of the respective marking element 11 is determined relative to the specified reference system xyz. This is typically a Cartesian coordinate system with an origin at the starting point of a measurement. The x-axis points in the direction of the track axis 34, the y-axis lies in the horizontal plane 26 perpendicular to the track axis 34, and the z-axis points upward.

[0032] In the case of the marking element 11 with a rectangular barcode 29, for example, the center line 35 is used to define a position point 42 on the track axis 34. Starting from the starting point of a measurement, a corresponding path x 17 which determines the position of the marking element 11. Position determination is simplified with the marking element 11, which has a triangular barcode 29. The triangle's vertex 33 determines the position of the detected position point 42.

[0033] The position data of the marking elements 11 and the identification codes are recorded synchronously and stored as linked data in a database. For example, the rail vehicle 6 includes a communication device for transmitting the data to a remote system control center. Maintenance plans and work orders for the tamping machine 37, for example, are created there. To perform tamping work, the identification codes and the linked position data are transmitted to the tamping machine 37. The tamping machine 37 is also equipped with optical and / or distance-measuring sensors 10 for automatically detecting the marking elements 11. The respective identification code is used to precisely determine the position of the tamping machine 37. This enables efficient, high-quality track maintenance.

Claims

Patent claims 1. Marking element (11) for marking and identifying a location (12) of a track (1), with a fastening means for fastening to a rail (5) of the track (1) and with an identification means, characterized in that the marking element (11) is a sheet metal part which has an elastic clamp (19) for clamping to a rail foot (18) as a fastening means and an identification code in the form of a three-dimensional structure (20) as an identification means.

2. Marking element (11) according to claim 1, characterized in that the sheet metal part is designed as a one-piece bent sheet metal strip.

3. Marking element (11) according to claim 1 or 2, characterized in that a clip-shaped sheet metal section (21) forms the elastic clamp (19).

4. Marking element (11) according to one of claims 1 to 3, characterized in that in the installed position an identification section (22) of the sheet metal part encloses an angle (a) between 5° and 85°, in particular between 15° and 75°, with a horizontal plane (26).

5. Marking element (11) according to one of claims 1 to 4, characterized in that elements of the identification code are arranged as openings (23) and / or depressions (24) and / or elevations (25).

6. Marking element (11) according to claim 5, characterized in that the elements of the identification code are limited by an envelope (32) in the form of a geometric figure with a tip (33) which, in the installed position of the marking element (11), points in the direction of a position point (42).

7. Marking element (11) according to one of claims 1 to 6, characterized in that the identification code is a bar code (29) and that the bars of the bar code (29) are aligned approximately parallel to a track longitudinal direction (30) in the installed position.

8. Method for identifying a location (12) of a track (1) by means of a rail vehicle (6, 37) which comprises an optical and / or distance-measuring sensor (10) directed onto the track (1), characterized in that a marking element (11) according to one of claims 1 to 7 clamped onto a rail (5) of the track (1) is detected by means of the optical and / or distance-measuring sensor (10).

9. The method according to claim 8, characterized in that a captured image (41) of the three-dimensional structure (20) arranged on the marking element (11) is evaluated in a computer (15) by means of a pattern recognition algorithm.

10. Method according to claim 8 or 9, characterized in that simultaneously with the detection of the marking element (11) a position of the rail vehicle (6, 37) in an associated reference system (xyz) is detected.

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