EP4263277A1

EP4263277A1 - Measurement system and method for measuring the elasticity of an overhead line of a track

Info

Publication number: EP4263277A1
Application number: EP21836110.3A
Authority: EP
Inventors: Florian Auer; Martin BÜRGER; Gerald Zauner
Original assignee: Plasser und Theurer Export Von Bahnbaumaschinen GmbH
Current assignee: Plasser und Theurer Export Von Bahnbaumaschinen GmbH
Priority date: 2020-12-15
Filing date: 2021-12-10
Publication date: 2023-10-25
Also published as: US20240043048A1; JP2024501630A; WO2022128792A1; CN116529145A

Abstract

The invention relates to a measurement system for measuring the elasticity of an overhead line (5) of a track (4), having a contactless sensor (8) for sensing the position of a measurement point (13) of the overhead line (5) and having an evaluation device (11) for calculating the elasticity. There is arranged a mechanical excitation device (7) by means of which the overhead line (5) can be made to vibrate by active excitation, wherein the sensor (8) is configured to capture a vibration profile, and wherein the evaluation device (11) is configured to derive mechanical properties of the overhead line (5) from the vibration profile. The mechanical properties, such as the elasticity, of the overhead line (5) are derived in the evaluation device (11) from the characteristics of the corresponding vibration curves (12).

Description

description

Measuring system and method for measuring the elasticity of an overhead line on a track

technical field

The invention relates to a measuring system for measuring the elasticity of an overhead line on a track, with a non-contact sensor for detecting the position of a measuring point on the overhead line and with an evaluation device for calculating the elasticity. In addition, the invention relates to a corresponding method and a track construction vehicle.

State of the art

[02] The quality of an overhead line on a track is decisive for trouble-free current collection by an electrically operated rail vehicle. Vibrations in the overhead line must be avoided, particularly at high speeds. If vibrations occur, the contact between the pantograph and the contact wire can be broken, resulting in material damage and signs of wear.

[03] Railway operators such as Deutsche Bahn therefore require regular elasticity measurements on overhead lines. The elasticity of the contact wire, which is also referred to as the flexibility of the contact wire, is recorded. The non-uniformity of the elasticity over the longitudinal span between two masts is also evaluated in order to draw conclusions about the quality of the overhead line design.

[04] In the publication Puschmann, R. et al.: contact wire position measurement with ultrasound; Electrical Railways 109, July 2011, Issue 7, pp. 323-330 describes a method for measuring elasticity. The position of the contact wire is recorded in two measurement runs using an ultrasonic sensor. The first measurement takes place in the unloaded state. During the second measurement, an adjustable force (e.g. 100N) is exerted on the contact wire using a measuring pantograph. In an evaluation device, the two superimposed measurements provide the elasticity of the contact wire. Concrete a lift of the contact wire divided by the contact force gives the elasticity.

Presentation of the invention

The object of the invention is to improve a measuring system of the type mentioned at the outset in such a way that an elasticity measurement of the overhead line can be carried out with one measurement run. Another object of the invention is to specify a corresponding method and an extended structure of the measuring system.

[06] According to the invention, these objects are achieved by the features of claims 1, 7 and 10. Dependent claims specify advantageous refinements of the invention.

[07] A mechanical excitation device is arranged, by means of which the overhead line can be made to vibrate by active excitation, the sensor being set up to record a vibration pattern and the evaluation device being set up to derive mechanical properties of the overhead line from the vibration pattern. With the measuring system according to the invention, the overhead line is set in a defined vibration, the resulting damped vibration being detected by the sensor. In contrast to a static load, active excitation results in a pulsed or abrupt energy input into the overhead line. The catenary is plucked or struck like the string of an instrument. The resulting waveform over time is recorded.

[08] From the characteristics of the corresponding oscillation curves (amplitudes, damping constants, phase position), the mechanical properties such as the elasticity of the overhead line are derived in the evaluation device. The dynamic measurement according to the invention allows several parameters of the mechanical contact wire system to be determined. By comparing them with reference measurement results, specific cases of damage can also be identified and targeted maintenance measures can be derived from them. The sensor is advantageously an optical sensor, in particular a laser light section sensor or a 3D laser scanner. This means that high measuring rates can be achieved (several hundred measurements per second) in order to record the oscillation curve with sufficient accuracy. In particular, a 3D laser scanner can be used to record other track components. For example, the course of a rail top edge can be detected in order to set the position of the contact wire in relation to the position of the track in a simple manner.

[10] A development of the system provides that the excitation device comprises a base unit and a triggering unit, the triggering unit being adjustable relative to the base unit by means of an actuator. With this arrangement, the excitation device can initially be positioned with respect to the overhead line. The triggering unit is finely adjusted by means of the actuating drive in order to bring about the desired pulse-like excitation during the subsequent activation. Defined excitation amplitudes and/or defined excitation forces can be set by appropriately controlling the triggering unit.

[11] In an advantageous variant, the release unit comprises a hook which can be adjusted by means of a release drive relative to a holder. The hook is moved relative to the overhead line and loads it in a pulsed manner.

[12] Another advantageous embodiment of the tripping unit includes a holding element that can be adjusted by means of a tripping drive relative to a line receptacle. Here, the bias of the overhead line is briefly increased by means of the holding element. The holding element is then released abruptly and the overhead line is released, as a result of which there is an abrupt excitation of the overhead line. In any case, the excitation direction can be vertical according to the standard or in any other direction.

[13] To further improve the measurement quality, another non-contact sensor for detecting the vibration is arranged at a further measuring point at a defined distance from the sensor. So that's one Extended measurement to determine phase shifts and wave propagation times can be carried out.

[14] The method according to the invention for measuring the elasticity of an overhead line on a track using the measuring system provides that the overhead line is made to oscillate by means of the mechanical excitation device, that the vibration profile is recorded by the sensor at a measuring point and that the evaluation device is used to determine from the vibration profile at least a mechanical property of the overhead line is derived. In this way, the elasticity of the overhead line can be recorded in one measurement run.

[15] A further development of the method provides that the sensor is used to detect vibrations in a measuring point of a contact wire and synchronously to vibrations in a measuring point of a suspension cable. In this way, several oscillation curves are recorded, from whose characteristics (amplitudes, damping constants, phase position) further mechanical properties of the overhead line can be derived.

[16] In addition, it is advantageous if vibrations are detected at a measuring point at a distance in the longitudinal direction of the line by means of a further non-contact sensor. With this extended measurement method, the wave propagation times and other characteristic parameters can also be determined from the relative phase shifts between the measurement points.

[17] A further object of the invention is a track construction vehicle with a vehicle frame which is supported on rails and can be moved on a track, the measuring system described being arranged on the track construction vehicle. Existing equipment on the track maintenance vehicle, such as a 3D laser scanner, can be used as a component of the measuring system. In particular, a crane can be used to position the excitation device. The excitation device is attached to the crane boom and can be moved relative to the overhead line.

Brief description of the drawings [18] The invention is explained below in an exemplary manner with reference to the accompanying figures. They show in a schematic representation:

Fig. 1 Track construction vehicle with measuring system in a side view Fig. 2 Contact wire construction along a track Fig. 3 Optical sensor and contact wire

Fig. 4 measured oscillation curve of the contact wire

Fig. 5 excitation device with hook

Fig. 6 excitation device with holding element

Description of the embodiments

[19] The track construction 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 includes an overhead line 5 whose elasticity is determined by means of a measuring system arranged on the track construction vehicle 1 . For this purpose, an excitation device 7 is arranged on a crane 6, by means of which the overhead line 5 can be made to oscillate. A non-contact sensor 8 , for example a laser light section sensor, is arranged on the roof of the track construction vehicle 1 . In addition, there is another non-contact sensor 8 on the front of the vehicle, which is designed as a 3D laser scanner. The measuring system can be arranged in a corresponding manner on a track construction train, a tamping machine, a stabilizer, a measuring car and the like. All of these vehicles and vehicle combinations are referred to as track construction vehicle 1 with reference to the present invention. In addition, the measuring system can be designed as a separate system that is only temporarily carried on the track construction vehicle 1 .

[20] In the illustrated track construction vehicle 1, a lifting platform 9 is arranged on the vehicle frame 2, which can be used for repairs or maintenance work on the overhead line 5. A pantograph 10 can be used to supply the track construction vehicle 1 with power. Advantageously, an element of the excitation device 7 that comes into contact with the overhead line 5 is insulated, so that an excitation of the switched-on overhead line 5 is possible. The current collector 10 can also be used as a measuring current collector.

[21] In addition to the excitation device 7 and the sensors 8, the measuring system includes an evaluation device 11, to which the measurement results of the sensors 8 are supplied. A processor is arranged in the evaluation device 11 and evaluates a detected oscillation curve 12 . In this case, mechanical properties of the overhead line 5 are derived from characteristics of the oscillation curve 12 by means of suitable algorithms. The corresponding programming is the responsibility of the specialist.

[22] In Fig. 2 several measuring points 13 are located in an overhead line section. The construction shown includes masts 14 with booms 15, to which a suspension cable 16 and a contact wire 17 are attached. In addition, the tensioned contact wire 17 is connected to the suspension cable 16 via hangers 18 . Other constructions are also known which can also be made to oscillate according to the invention.

[23] The mechanical excitation of the overhead line 5 preferably takes place approximately in the middle between two masts 14. Preferred measuring points 13 on the contact wire 17 and on the supporting cable 16 are also provided at this point. Accordingly, the excitation device 7 and at least one sensor 8 are positioned in this area during a measurement process.

[24] Further measurements are carried out at a number of measuring points 13 spaced apart in the longitudinal direction 19 of the line, in order to determine wave propagation times. For example, the 3D laser scanner arranged on the front of a longer track construction train can be used for this purpose. The measurements are carried out synchronously at all measuring points 13 in order to be able to evaluate phase shifts in the recorded oscillation curves.

[25] In Fig. 3 designed as a laser light section sensor sensor 8 and the contact wire 17 with the detected measuring point 13 are shown. The position of the measuring point 13 is recorded in a defined coordinate system XYZ with a high temporal and spatial resolution. In particular, at least one hundred measurements per second are made with an accuracy of 0.1 mm. The z-axis of the coordinate system is in Line longitudinal direction 19 aligned. The X-axis points in the lateral direction and the Y-axis points in the direction of the acceleration due to gravity.

[26] The excitation of the overhead line 5 can be carried out in accordance with the standard in the Y direction or in any other direction. The resulting damped vibration is recorded in the X-direction and Y-direction at measuring point 13. Taking into account a mounting angle of the sensor 8 relative to the Y direction, the measured vibrations can also be detected relative to the acceleration due to gravity.

[27] FIG. 4 shows an exemplary oscillation curve 12 that was recorded at a measuring point 13 in a direction y over time t. Depending on the number of selected measurement points 13 and the direction of excitation, a large number of such oscillation curves 12 result, which are subsequently evaluated together by means of the evaluation device 11 . The amplitudes and phases of the individual oscillation cycles can be recorded directly. A damping constant can be derived from the decreasing amplitudes.

[28] By comparing several synchronized oscillation curves 12, relative phase shifts can be detected. This results in wave propagation times and other characteristic parameters, from which the mechanical properties of the overhead line emerge. A non-uniformity of the elasticity can also be detected by measuring at a plurality of measuring points 13 in the longitudinal direction 19 of the line. From this it is easy to deduce the quality of the overhead contact line design.

[29] A first exemplary embodiment of the excitation device 7 is shown in FIG. A pivotable base unit 21 is located on a crane boom 20. A triggering unit 23 can be adjusted relative to the base unit 21 via an actuator 22. The release unit 23 includes a hook 24 which can be adjusted relative to a holder 26 by means of a release drive 25 .

[30] In preparation for a measurement run, the tripping unit 23 is positioned by means of the crane arm 20. The fine adjustment of the position of the hook 24 over the contact wire 17 is carried out by means of the actuating drive 22. When the release drive 25 is actuated, the hook sweeps over the contact wire 17 and causes a pulse-like energy input. This active excitation causes the overhead line 5 to vibrate.

[31] Advantageously, the sensor 8 is also arranged on the base unit 21. In this way, there is always a clear spatial relationship between the excitation point and the measuring points 13 on the contact wire 17 and on the support cable 16 located above.

[32] FIG. 6 shows an alternative embodiment of the excitation device 7. Here the triggering unit 23 comprises a retaining element 27 which can be adjusted in relation to a line receptacle 28 by means of a triggering drive 25. Before activation, the triggering unit 23 is positioned by means of the crane 6 in such a way that the contact wire 17 is accommodated in the line receptacle 28 when the retaining element 27 is released.

[33] Subsequently, the holding element 27 is pivoted and locked by means of the release drive 25 down. An electrically operated rotary drive, for example, is used as the release drive 25 . By actuating the actuator 22, the triggering unit 23 is moved downwards, as a result of which the holding element 27 pulls the contact wire downwards by a defined adjustment path. A defined force can also be exerted via the actuator 22 (e.g. a pneumatic or hydraulic cylinder with displacement sensor). For sudden excitation of the overhead line 5, the locking of the holding element 27 is released via the release drive 25. The holding element 27 abruptly releases the contact wire 17, causing the overhead line 5 to vibrate.

[34] The invention also includes other excitation devices 11 which are suitable for causing the overhead line 5 to oscillate by means of a pulsed or abrupt excitation. For example, contact wire 17 can be struck by means of a striking element. It should be noted that the impact element has a flat contact zone in order to prevent damage to the contact wire.

Claims

9 patent claims

1. Measuring system for measuring the elasticity of an overhead line (5) on a track (4), with a contactless sensor (8) for detecting the position of a measuring point (13) of the overhead line (5) and with an evaluation device (11) for calculating the elasticity, thereby characterized in that a mechanical excitation device (7) is provided, by means of which the overhead line (5) can be made to vibrate by active excitation, that the sensor (8) is set up to record a vibration pattern and that the evaluation device (11) is designed to derive mechanical Properties of the overhead line (5) is set up from the waveform.

2. Measuring system according to claim 1, characterized in that the sensor (8) is an optical sensor, in particular a laser light section sensor or a 3D laser scanner.

3. Measuring system according to claim 1 or 2, characterized in that the excitation device (7) comprises a base unit (21) and a triggering unit (23) and that the triggering unit (23) can be adjusted relative to the base unit (21) by means of an actuator (22). is.

4. Measuring system according to claim 3, characterized in that the triggering unit (23) comprises a hook (24) which can be adjusted relative to a holder (26) by means of a triggering drive (25).

5. Measuring system according to claim 3, characterized in that the triggering unit (23) comprises a holding element (27) which can be adjusted by means of a triggering drive (25) relative to a line receptacle (28).

6. Measuring system according to one of claims 1 to 5, characterized in that a further non-contact sensor (8) for detecting the vibration in a further measuring point (13) is arranged at a defined distance from the sensor (8).

7. Method for measuring the elasticity of an overhead line (5) on a track (4) using a measuring system according to one of Claims 1 to 6, characterized in that the overhead line (5) is made to oscillate by means of the mechanical excitation device (7) so that the oscillation profile is detected by the sensor (8) at a measuring point (13) and that by means of the evaluation device (11) at least one mechanical property of the overhead line (5) is derived from the vibration profile.

8. The method according to claim 7, characterized in that vibrations in a measuring point (13) of a contact wire (17) and synchronously vibrations in a measuring point (13) of a support cable (16) are detected by means of the sensor (8).

9. The method according to claim 7 or 8, characterized in that vibrations in a line longitudinal direction (19) distanced measuring point (13) are detected by means of a further contactless sensor (8).

10. Track maintenance vehicle (1) with a vehicle frame (2) which is supported on rail chassis (3) and can be moved on a track (4), characterized in that the measuring system according to one of claims 1 to 6 is arranged on the track maintenance vehicle (1). .