TW202235840A - Ground contact and operating method - Google Patents

Abstract

The invention relates to a method for operating of a rail vehicle having a ground contact (20), to a ground contact and to a monitoring system, the rail vehicle having the ground contact on a wheel set having an axle and wheels, the ground contact having a housing unit (22), a contact device (26) and a sensing device (61), the contact device having a contact piece (28) which is disposed on a contact surface of an axle, an electrical sliding contact being formed between the contact surface and the contact piece, the ground contact comprising a measuring unit having a measuring device (63), at least one sensor (65) of a sensing device (61) of the measuring device being disposed on the contact device and/or adjacent to the contact device, a measured value of the contact device being registered by means of the sensing device, the measured value being processed by means of the processing unit (62) of the measuring device and a parameter describing an operating state of the wheel set and/or a guide rail being determined.

Description

Grounding contacts and how to operate them

The invention relates to an earth contact and to a method for operating a rail vehicle having an earth contact on a wheel set with an axle and wheels, the earth contact having a housing unit, contact means and sensing means, The contact device has a contact piece arranged on the contact surface of the axle, and an electric sliding contact is formed between the contact surface and the contact piece.

Ground contacts and methods of this type are well known from the state of the art and are commonly used on axles of rail vehicles, in particular electrically driven rail vehicles. The ground contact is used to transmit current to the rail via the axle of the wheel set. It is known that the ground contact can be arranged on an axial side of the axle and can be non-rotatably connected to the axle support of the rail carrier or connected for co-rotation with respect to the axial side. The ground contact comprises a housing with a flange-like housing cover or housing cover arranged on an axial side, the contact piece made of graphite is electrically connected to the axle or a corresponding slip ring or slip disk inside the housing for the transmission of electrical current. Furthermore, it is known to mount a sensing device or a flange-like sensor housing on the housing cover. The housing cover has an opening through which a rotary encoder such as a sensing device can detect a signal generated by axial rotation. These signals are transmitted via cables to the vehicle control system, which generates axle speed, pulses from the engine control or braking system. Thus, the sensors transmit signals to the vehicle control system, which processes the signals for control purposes. A ground contact of this type is known, for example, from EP 2 423 068 A1.

As the contacts of the ground contacts are in constant contact with the axle or rotating components of the axle, the contacts wear due to wear of the material or graphite of the contacts. Therefore, frequent maintenance of the ground contacts is necessary to ensure that the respective ground contacts are functional. This maintenance is always carried out in the warehouse of the rail carrier during maintenance intervals, whereby a partial disassembly of the housing unit of the inspection contacts is required. Also replace contacts that have not fully worn out at this time. Overall, this increases the workload for performing maintenance on the ground contacts and replacing the contacts.

It is therefore an object of the present invention to propose a method for operating a rail carrier and to propose a grounding contact and a monitoring system with the grounding contact allowing improved handling.

This object is achieved by a method according to claim 1 , by a ground contact according to claim 15 and by a monitoring system according to claim 16 .

According to the method of the invention for the operation of a rail carrier, the rail carrier is formed with at least one ground contact on a wheel set with an axle and wheels, the ground contact has a housing unit, a contact device and a sensing device, the contact The device has a contact piece arranged on the contact surface of the axle, an electric sliding contact is formed between the contact surface and the contact piece, the ground contact comprises a measurement unit with a measurement device, at least one of the sensing devices of the measurement device The sensor is arranged on and/or adjacent to the contact device, by means of the sensing device the measurement value of the contact device is determined, by means of the processing unit of the measurement device the measurement value is processed, and the determination describes the wheel set and/or Parameters of the operating state of the rail.

The ground contact is placed on a wheel set which can be a rear wheel set, a drive wheel set or an individual wheel set with one or more axles. One or more axles of the wheel set each have two wheels which are mounted on guide rails of a rail vehicle or each mounted on a rail and can roll on them. The ground contact arranged on the axle and inside the housing unit has a contact device with at least one contact piece. The contact device is used for installing the contact piece and establishing electrical connection with the contact piece. The axle or a component mounted on the axle forms a contact surface of the axle that is rotatable relative to the contact piece. By means of the contact piece, radial or axial contact can be made to the axle. Furthermore, the contact device may comprise a plurality of contact elements. In particular, the contacts can be made of graphite.

The method of the invention contemplates that the ground contact comprises a measuring unit having a measuring device having a sensing device having at least one sensor. The sensor is arranged on the contact device and/or is arranged adjacent to the contact device or as close as possible to the contact device or the contact. The measured values of the contact device or contact piece are recorded by means of a sensing device or sensor. This measurement is a physical measurement variable directly operatively linked to the contact device and variable during operation of the ground contact. The measured values or measured variables measured by the sensors are then processed by means of the processing unit and parameters suitable for describing the operating state of the ground contact and/or the guide rail are determined. Parameters can be parameter values, characteristic variables, key figures (key figures), or datasets. Parameters can also be included in the data set. In particular, it is intended to digitally process the measured values by means of a processing unit in order to obtain parameters suitable for further digital processing. Thus, the processing unit is formed by at least one digital electronic circuit capable of processing analog and/or digital signals of the sensor. For example, the processing unit can also be a programmable logic controller (programmable logic controller; PLC), an integrated circuit (an integrated circuit; IC) or a computer.

Since the processing unit determines parameters suitable for describing the operating state of the grounding contacts, it becomes possible to determine the operating state of the grounding contacts, the wheel set and/or the guide rail or to monitor the grounding contacts. Since the operating state of the ground contact also mainly depends on the state or operating state of the wheel set and/or the guide rail, the parameter may also describe the operating state of the wheel set and the guide rail. For example, the operating state may be a state of wear, making it possible to make statements about the state of wear based on parameters. Overall, maintenance on ground contacts, wheelsets and rails can be performed in a more targeted manner without having to follow regular maintenance intervals. Overall, therefore, overall more economical handling of ground contacts, wheel sets or guide rails and thus of the rail carrier becomes possible.

Velocity, acceleration, frequency, temperature, air humidity, force, current, voltage, distance, mass and/or position of the axle can thus be recorded and processed continuously or discontinuously as measured values. Based on the speed of the wheel axle, the driving speed or driving path of the rail vehicle can be measured. For example, a rotary encoder on a wheel shaft or another suitable sensor could be used for this. A temperature sensor can be used to measure the temperature on the ground contact or directly on the housing unit or the contact device, so that a possible heating of the wheel and thus a possible overheating of the bearings of the wheel axle can be determined. The force can be determined by means of strain gauges, force sensors, pressure sensors or the like. For example, the contact pressing force of the contacts can thus be measured. Current or voltage can be measured using an ammeter or voltmeter as a sensor. For example, the current discharged via the ground contact can then be determined. The location of the ground contact can be easily determined using a satellite navigation system such as GPS. One or more measurements may be determined or processed continuously or sequentially. It is also possible to record and process one or more measured values discontinuously, eg at time setpoints or on certain occasions.

It is especially advantageous if at least one acceleration sensor which can be arranged on the contact device, preferably on the contact piece, is used as sensor. Acceleration sensors or vibration sensors can be used to measure the characteristic frequency and/or resonant frequency of the contact or the entire ground contact. For example, by means of an acceleration sensor, the movement of a contact on a wheel axle can be detected, in which case conclusions can be drawn about the design of the guide rail or wheel wear on the rim of the wheel from the movement. Therefore, irregularities in the course of guiding can be easily judged. Therefore, it is no longer necessary to carry out specific measurement drives or on-site inspections of the guide rails to determine such defects. Furthermore, changes in the contacts due to wear or wear on the axle cause the characteristic and/or resonant frequencies of the contacts to change. The difference between new and worn contacts can come from this. Since the contact is constantly in contact with the axle during the drive of the rail vehicle, the processing unit can derive a change in the contact from a change in the characteristic frequency and/or resonant frequency of the contact. For example, the characteristic frequencies and/or resonant frequencies of new and worn contacts can be stored in the processing unit, in which case the processing unit can make a comparison and determine the wear state or usage state of the contacts without further calculations . This wear can then be output as a parameter. In addition, damage to the contacts can be easily judged.

The processing unit can record and store the measured values and/or parameters of the sensors at fixed time intervals, when changes occur, or continuously. It is therefore conceivable to record and store measured values and/or parameters only when the values change, in order to minimize the amount of data. Alternatively, sequential, in other words, sequential recording and storage may be desired. By storing measured values and/or parameters, processing can be performed even after recording. For example, measured values can be recorded during the drive of the rail carrier, in which case a determination of one or more parameters can then be performed once the rail carrier has been tested in the warehouse. In this way, for example, the condition of the guide rail along the route of the rail carrier can be determined after driving.

The measurement device can transmit measured values and/or parameters to the evaluation unit, which can be stored in a database of the evaluation unit and/or can be processed by means of the evaluation device of the evaluation unit. An evaluation unit may thus comprise a database and an evaluation device. Therefore, the evaluation unit can be used to collect and process measured values and/or parameters and can be a computer. For example, the evaluation device can display or output the evaluation results to the operator. The evaluation unit can have a greater scope of functions than the processing unit. In principle, however, it is also possible to integrate the processing unit in the evaluation unit and vice versa. In principle, an evaluation unit of this type can also be provided as a module for a rail carrier that is not associated with ground contacts.

The measured values and/or parameters of the measuring device can be transmitted by means of a transmission unit of the measuring device via a data link to an evaluation unit configured to be placed at a distance from the measuring unit or integrated in the measuring unit middle. If the control device or the evaluation unit is integrated in the measuring unit, the data link can easily be formed by a wire connection. It is then also possible to mount parts of the measuring device, such as the processing unit and the control device as well as the evaluation unit, elsewhere on the rail carrier, for example on the operator's stand. For example, when transmitting measured values and/or parameters, data can be exchanged based on a transmission protocol. Data links can be established continuously, at regular intervals, or so as to be triggered by sporadic events. In general, this allows the collection and evaluation of the data collected by the measurement device. The analysis of certain conditions and contingencies then provides various opportunities for evaluation by which the operation of the ground contacts, wheelset and guide rail or track carrier can be optimized.

A data link can be formed via an external data network. In this case, the data link may be formed via a mobile network, a wireless network, a satellite connection, the Internet or any other wireless standard by itself or in combination. If the evaluation unit is arranged at a distance from the measuring unit, it can also be arranged outside the rail carrier, away from the rail carrier and in order to be fixed, for example, in a building. In particular, it thus becomes possible to monitor the function of the ground contacts and the wheel sets on the rail vehicle without the need for a person to perform this task on the rail vehicle itself.

A data link to the evaluation unit and/or to the measurement unit can be formed by means of the user unit, measured values and/or parameters can be transmitted and configured for output to the user unit. The user unit can be a computer independent of the evaluation unit and/or the measurement unit. This computer can be a stationary computer, a mobile device or the like, by means of which another data link can be established for exchanging data with the evaluation unit and/or the measurement unit. For example, data may be exchanged via an external data network, such as the Internet. In this way, the data processed by the evaluation unit or the measured values and/or parameters processed using the evaluation device can be made available to a wider range of users. For example, the evaluation unit can be a server with software that transmits the information stored in the evaluation unit's database to the user unit. This transmission can be made by providing a website with selected information, such as the current state of wear of the contacts.

Taking into account time-dependent components and/or components depending on wear-related measured variables, the processing unit or evaluation unit can evaluate the time curve of the measured values and/or parameters and determine the wear of the contacts, wheelsets and/or guide rails state. It is thus not only possible to provide information about the current state of wear, but even to determine at what point in time eg the contact or the wheel is subject to wear. Thus, maintenance intervals for ground contacts or other components of a wheel set can be precisely scheduled and timing can be optimized. In addition, the time points at which some accidental events occur can be determined by means of time curves. On this basis, if the occasional event occurs repeatedly, the schedule can be derived. For example, when driving over a certain section of the route, poor rail condition or increased wear may be observed.

The vibration of the contacts can be recorded by means of a sensing device, the processing unit is configured to determine the characteristic frequency and/or resonance frequency of the contacts and/or the axle, the processing unit or evaluation unit is configured to determine the contacts, the wheel set and /or the state of wear of the rails. When a contact is worn, the shape, in particular the height, of the contact can change, in which case the change in shape can change the characteristic and/or resonant frequency of the contact. The wear state of the contacts and/or the axle can be determined from the characteristic frequency and/or the resonant frequency by means of the processing unit. If the characteristic frequency and/or the resonant frequency changes as the carbon self-contact or component of the self-axle wears out, conclusions about the state of wear of the contact and/or the axle can be drawn from the changes. Thus, it is possible not only to determine whether the contact is new or completely worn, but also to determine to what extent the contact has been used.

The processing unit or evaluation unit can perform pattern analysis on the measured values and/or parameters stored over a period of time and derive key values from the pattern analysis. It may also be desirable to perform pattern analysis using artificial intelligence. The processing unit or evaluation unit can correlate the measured values and/or parameters of the different sensors and derive the functional dependencies of the measured values and/or parameters. Thus, functional dependencies among the sensors can be detected. For example, vibrations or oscillations can be compared with temperature and from this it can be possible to determine that the bearings of the wheel axle are damaged. In this way, several other operating conditions and contingencies can be detected and interpreted as the result of functional dependencies, such as the load state of the rail vehicle or the individual wagon, inclination and bending of the guide rail, due to Contact wear due to mechanical friction, route sections of guide rails with particularly turbulent operating characteristics of the axle and thus particularly high or low wear, wear rate depending on driving behavior, such as acceleration or parking of the rail vehicle Condition, damage of wheelsets, axles, components of wheels, damage of wheel bearings and contact devices, discharge of current through ground contacts and resulting faults on components, condition of worn components of wheelsets, such as bearings, joints Point and structural elements, loss of components, e.g. due to collisions with obstacles, as well as position, velocity, acceleration and direction of movement of rail vehicles. Such exemplary situations and incidents may thus be addressed by maintenance measures, by adjusting the driving behavior of the rail vehicle, or by implementing other suitable measures.

It is also contemplated that a processing unit or an evaluation unit may use signals or measurements and/or parameters of sensors not associated with ground contacts as well as signals or measurements of sensors associated with ground contacts and/or or parameter dependent. For example, by additionally taking into account signals or measured values and/or parameters of sensors of current collectors of conductor rails, pantographs, wheel flange lubrication, shaft grounding, etc.

The position of the ground contact can be determined by means of the position sensor of the sensing device, which position is associated with a parameter, and the evaluation unit is configured to determine the state of wear of the guide rail. For example, the position sensor can determine the position of the ground contact and thus the position of the vehicle via satellite navigation. Thus, it can be determined in particular at which point on the route a certain measurement value of another sensor of the sensing device has been recorded. Accordingly, corresponding locations can be associated with incident events or measurements. Furthermore, it is possible by means of the evaluation unit to determine the state of wear of the guide rail, for example by evaluating vibrations of the contact device or of the contact pieces caused by the wheels along the guide rail. Therefore, when the rails are severely worn, the vibration mode of the contact device can change. Additionally, grooves, irregularities, and cambers along the rail can be determined and associated with locations on the route. This can have an effect on the speed of rail vehicles in sections of the route that have been positioned in this way.

The evaluation unit can process the parameters of the measuring unit for several ground contacts. Thus, the evaluation unit can process the parameters of a plurality of ground contacts arranged on an individual rail carrier or on a wheel set. The accuracy of the measurement or monitoring can be further increased by comparing the parameters of the ground contacts. Furthermore, parameters of ground contacts arranged on different rail carriers can be processed by means of the evaluation unit. This can also significantly improve the accuracy of measurement and monitoring of rail vehicles or individual guide rails. In addition, this provides current and constantly changing status reports on the route network and vehicles operating in the route network. The resulting optimization of operating conditions can significantly reduce operating costs. Regular and frequent monitoring of infrastructure and rail vehicles is no longer necessary to this extent, and operational safety is significantly increased. Furthermore, no specific metrology drivers are required anymore.

According to the invention, the ground contact of the wheel axle for the wheel set of the rail vehicle has a housing unit, a contact device and a sensing device, the contact device has a contact piece arranged on the contact surface of the wheel axle, and the electric sliding contact can be formed on Between the contact surface and the contact piece, the ground contact comprises a measuring unit with a measuring device, at least one sensor of the sensing device of the measuring device is arranged on the contacting device and/or adjacent to the contacting device, which can be obtained by means of The sensing device records the measured values of the contact device, the measured values can be processed by means of the processing unit of the measuring device, and parameters describing the operating state of the wheelsets and/or guide rails can be determined. For further details regarding the advantages of the ground contact according to the invention, reference is made to the description of the advantages of the method according to the invention. The housing unit may be formed by a housing body and a housing cover. Further advantageous embodiments of the ground contact are apparent from the description of the features of the dependent claim with reference to the method of claim 1 .

A monitoring system according to the invention comprises at least one rail carrier with at least one ground contact according to the invention.

The monitoring system may comprise a plurality of measuring units and an evaluation unit for processing the measured values and/or parameters of the measuring units of the plurality of ground contacts. As described above, it thus becomes possible to monitor a rail carrier with an earth contact or a plurality of earth contacts of a plurality of rail carriers using only one evaluation unit.

Thus, the monitoring system may comprise a plurality of rail carriers each having at least one ground contact. It may also be desirable for the track carriers to each have a plurality of ground contacts.

Referring back to the method of claim 1, further advantageous embodiments of the monitoring system are apparent from the description of the features of the dependent claims.

FIG. 1 shows a ground contact 10 on an axle 11 of a rail carrier 12 (which is only partially shown). The axle 11 has two wheels 13 that can each roll on a guide rail 14 . Mounting means 16 for mounting the axle 11 so as to be rotatable are arranged on the axial end 15 of the axle 11 . On the mounting device 16 the axle 11 is connected to the damping device 17 of the frame 18 with the wheel set 19 of the rail carrier 12 . The ground contact 10 is flange mounted on a mounting device 16 .

FIG. 2 shows a cross-sectional view of a ground contact 20 on a wheel axle (not further shown) of a rail carrier. The axial end cap 21 of the wheel axle is shown by means of dotted lines. In addition, for the sake of simplification, the bearing seat of the wheel shaft screwed into the ground contact 20 is also not shown. The ground contact 20 includes a housing unit 22 separately formed by a housing body 23 and a housing cover 24 . Furthermore, the contact means 26 of the ground contact 20 are formed by a contact disc 27 and a contact piece 28 substantially made of graphite. The contacts 28 are accommodated in a contact support 29 and are each pressed against a contact disk 27 for forming an electrical sliding contact using a spring arrangement 30 . Furthermore, the contacts 28 are electrically connected to the contact support 29 by means of stranded wires 31 and the connector 32 is connected to the contact support 29 via a cable 33 which electrically connects the ground contact 20 to the motor, as is conventionally done. Know.

A sensing device 61 with an acceleration sensor (not further shown) is disposed in the housing cover 24 . An acceleration sensor or another suitable sensor can be arranged on the housing unit 22 or the contact device 26 or the ground contact 20 . The signal detected by the acceleration sensor is processed by the processing unit 62 of the measurement device 63 in the housing cover 24 and transmitted to an external network (not shown) through the transmission unit 64 . Furthermore, the sensing device 61 comprises a temperature sensor 65 which in this case is arranged on the housing body 23 .

FIG. 3 is a schematic diagram of a specific example of the measurement unit 34 . The measurement unit 34 is formed by the measurement device 35 and further comprises an evaluation unit 36 . The measuring device 35 includes a sensing device 37 with a plurality of sensors 38 and a processing unit 39 . Furthermore, it is intended to supply the measuring device 35 with electrical energy by means of the supply unit 40 . The supply unit 40 may be, for example, an energy store, a generator or an external energy supplier via a rail carrier or a discharge current. The evaluation unit 36 has a database 41 and an evaluation device 42 and receives data or measured values and/or parameters from the processing unit 39 . The processing unit 39 receives measurements from the sensors 38 of the sensing device 37 and processes the measurements. The measured values relate to operating parameters or physical measurements of the contacting device of the ground contact (not shown) in the manner of the ground contact shown in an exemplary manner in FIGS. 1 and 2 , the processing unit 39 with The measured values are processed in such a way as to determine parameters describing the operating state of the respective current collector and/or conductor rail. The respectively determined parameters are continuously or sequentially transmitted from the processing unit 39 to the evaluation unit 36 and stored in the database 41 or processed using the evaluation device 42 .

FIG. 4 shows a monitoring system 47 with a measurement unit 48 . The monitoring system 47 may have a plurality of measuring units 48 . In contrast to the measuring unit of FIG. 3 , the measuring unit 48 has a measuring device 49 comprising a transmission unit 50 . The transmission unit 50 receives data or measured values and/or parameters from the processing unit 39 . Furthermore, between the transmission unit 50 and the external data network 51 there is a data link 52 by means of which measured values and/or parameters are transmitted using radio signals. The evaluation unit 54 with the database 55 and the evaluation device 56 is connected via a further data link 53 to the external data network 51 and exchanges data or measured values and/or parameters with the transmission unit 50 via the external data network 51 . In principle, this data can be exchanged directly via the direct data link 52 while bypassing the external data network 51 . Furthermore, a user unit 58 is provided which is connected to an external data network 51 via a further data link 59 . Thus, the user unit 59 can exchange data with the evaluation unit 54 , which means that the data of the measurement unit 48 processed by the evaluation unit 54 can be output or interpreted via the user unit 58 and made available for further use. The user unit 58 is directly connectable to the evaluation unit 54 via a direct data link 60 . Overall, measured values are thus obtained via sensors 38 mounted on ground contacts (not shown) and transmitted via an external data network 51, such as the Internet, directly to an evaluation unit 54 for use in storage and evaluation become possible. Thus, the functional dependencies of the data can be used, evaluated and interpreted. The results of these evaluations may be provided to the end user via the user unit 58 .

none

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. [ Fig. 1] is a side view of the first embodiment of the ground contact on the rail carrier; [ Fig. 2] is a cross-sectional view of the second embodiment of the ground contact on the rail carrier; [ Fig. 3] is the measurement A schematic diagram of a specific example of a measurement unit; [ Figure 4] is a schematic diagram of a monitoring system.

Claims (18)

A method for operating a rail vehicle (12) having a ground contact (10, 20) on a wheel set (19) with an axle (11) and wheels (13), the ground contact The contact has a housing unit (22), a contact device (26) and a sensing device (37, 61), the contact device has a contact piece (28) arranged on a contact surface of the wheel axle, an electric a sliding contact is formed between the contact surface and the contact piece, It is characterized in that, The ground contact comprises a measuring unit (34, 48) having a measuring device (49, 63), at least one sensor (38, 65) of a sensing device (37, 61) of the measuring device ) is arranged on and/or adjacent to the contacting device, a measured value of the contacting device is recorded by means of the sensing device, the quantity is processed by means of a processing unit (39, 62) of the measuring device and determine a parameter describing an operating state of the wheel set and/or a guide rail (14). If the method of claim 1, It is characterized in that, Continuously or discontinuously recording and processing a velocity, an acceleration, a frequency, a temperature, an air humidity, a force, a current, a voltage, a distance, a mass and/or a position as a measured value . If the method of claim 1 or 2, It is characterized in that, As a sensor (38, 65), at least one acceleration sensor is used, which is arranged on the contact device (26), preferably on the contact piece (28). As in any one of the preceding claims, It is characterized in that, The processing unit (39, 62) records and stores the measured values and/or the parameters of the sensors (38, 65) at regular time intervals, when a change occurs, or continuously. As in any one of the preceding claims, It is characterized in that, The measuring device (49, 63) transmits the measured values and/or the parameters to an evaluation unit (36, 54), the measured values and/or the parameters are stored in one of the evaluation units database (41, 55) and/or by means of an evaluation device (42, 56) of the evaluation unit. If the method of claim 5, It is characterized in that, The measured values and/or the parameters of the measuring device (49, 63) are via a data link (52, 53) by means of a transmission unit (50, 64) of the measuring device (49, 63) , 57, 60) to the evaluation unit (36, 54), which is arranged at a distance from the measurement unit (34, 48) or integrated in the measurement unit. For the method of claim 6, It is characterized in that, The data link (52, 53, 57, 60) is formed via an external data network (51). If the method of any one of claims 5 to 7, It is characterized in that, By means of a user unit (58) a data link (52, 53, 57, 60) is formed to the evaluation unit (36, 54) and/or to the measurement unit (34, 48), the quantities Measured values and/or the parameters are transmitted and output to the user unit. If the method of any one of claims 5 to 8, It is characterized in that, taking into account a time-dependent component and/or a component dependent on wear-related measured variables, the processing unit (39, 62) or the evaluation unit (36, 54) evaluates the measured values and/or the parameters A time curve, and determine a wear state of the contact piece (28), the wheel set (19) and/or the guide rail (14). If the method of any one of claims 5 to 9, It is characterized in that, By means of the sensing device (37, 61) recording a vibration of the contact (28), the processing unit (39, 62) determines a characteristic frequency of the contact and/or the axle (11) and/or a Resonant frequency, the processing unit or the evaluation unit (36, 54) determines a wear state of the contact piece, the wheel set (19) and/or the guide rail. If the method of any one of claims 5 to 10, It is characterized in that, The processing unit (39, 62) or the evaluation unit (36, 54) performs a pattern analysis on the measured values and/or the parameters stored over a time period and derives a key value from the pattern analysis. If the method of any one of claims 5 to 11, It is characterized in that, The processing unit (39, 62) or the evaluation unit (36, 54) correlates the measured values and/or the parameters of the different sensors (38, 65) and derives the measured values and/or Functional dependencies of these parameters. If the method of any one of claims 5 to 12, It is characterized in that, By means of a position sensor of the sensing device (37, 61) determining a position of one of the ground contacts (10, 20), which position is associated with the parameters, the evaluation unit (36, 54) determines One of the rails (14) is in a state of wear. As in any one of the preceding claims, It is characterized in that, The evaluation unit (36, 54) processes parameters of a measuring unit (34, 48) of a plurality of ground contacts (10, 20). A ground contact (10, 20) for a wheel axle (11) of a wheel set (19) of a rail vehicle (12), the ground contact having a housing unit (22), a contact device (26) and a sensing device (37, 61) having a contact piece (28) arranged on a contact surface of the axle, an electrical sliding contact being formed between the contact surface and the contact piece, It is characterized in that, The ground contact comprises a measuring unit (34, 48) having a measuring device (49, 63), at least one sensor (38, 65) of a sensing device (37, 61) of the measuring device ) is arranged on and/or adjacent to the contacting device, a measurement value of the contacting device can be recorded by means of the sensing device, can be processed by means of a processing unit (39, 62) of the measuring device The measured value, and a parameter describing the operating state of the wheelset and/or a guide rail (14) can be determined. A monitoring system (47) having at least one rail carrier (12) having at least one ground contact (10, 20) according to claim 15. Such as the monitoring system of claim 16, It is characterized in that, The monitoring system (47) comprises measuring units (38, 48) and an evaluation unit ( 36, 54). If the monitoring system of claim 16 or 17, It is characterized in that, The monitoring system (47) includes a plurality of rail carriers (12) each having at least one ground contact (10, 20).

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