DE102021208395A1 - System for detecting a state of wear of a pantograph, pantograph with such a system, and traction vehicle with such a pantograph - Google Patents

Abstract

The invention relates to a system (30) for detecting the state of wear of a current collector (8) arranged on an electric traction vehicle (1). The pantograph (8) has at least one sliding contact piece (19) provided for contacting a contact wire (3) of an overhead line system. The system (30) comprises at least one reference body (33, 34, 34a to 34d) which has a reference surface (35) and is firmly connected to the pantograph (8) in such a way that while the traction vehicle (1) is moving between the sliding contact piece (19 ) and reference surface (35) there is a fixed relative position. It also includes a sensor device (31) which is arranged on the track side and designed to detect a height profile (h) of the sliding contact piece (19) above the reference surface (35) by means of a steerable scanning beam (32). An evaluation unit (37) is connected to the sensor device (31), by means of which status data representing a wear status of the sliding contact piece (19) can be determined from the recorded height profile (h). As a result, the status data can be recorded more simply and reliably.

Description

The invention relates to a system for detecting a state of wear of a pantograph arranged on an electric traction vehicle according to the preamble of patent claim 1.

Current collectors for supplying energy from an electrical catenary system have long been used for electrically driven rail vehicles on the railways in the form of scissor or semi-scissor pantographs. Pantographs in the form of pole pantographs have also been known for a long time in track-bound trolleybuses. For some time now, pantographs have also been tested for electrically or diesel-electrically driven road vehicles, in particular for heavy commercial vehicles such as trucks, articulated lorries and tractor units. Current collectors for all of these electric traction vehicles include a contact strip or a contact shoe with an electrically conductive sliding contact piece. During operation of the traction vehicle, the sliding contact piece can be pressed against a contact wire of the overhead line system for energy transmission, which is thereby subject to material wear and must therefore be replaced at the latest after a certain idle time, or earlier if damaged. Status data representing the wear status of the sliding contact piece can be recorded by means of a sensor device in order to determine a maintenance or repair requirement and, if necessary, to prohibit locomotives with worn pantographs from operating on the overhead line system.

The disclosure document DE 10 2009 006 392 A1 shows an arrangement for monitoring the operational condition and wear condition of sliding contact devices of electrically driven, rail-bound vehicles. The sliding contact devices are each arranged on a pantograph device that can be lowered and raised. A power supply network has a power line arranged above the vehicle, which is arranged hanging from a plurality of spaced-apart power poles. An image capture system for automatically capturing images of the sliding contact device of a passing vehicle is arranged on at least one power pole or on the power line. The image acquisition system has a number of electronic cameras, each of which is oriented at a different angle to the sliding contact device. The image recordings are transmitted as a coherent image data record to a computer for image processing and/or evaluation. Finally, a human operator examines the recorded images of the sliding contact device visually on a monitor, where he can be relieved or supported by a program application using software-based image recognition.

From the international application WO 2015/007718 A2 a system for detecting a state of a pantograph of an electrically powered vehicle is known. It includes a video camera device for digitally recording images of the pantograph and an image evaluation device for evaluating the data from the recorded images. The current collector has optically detectable markings whose position and/or shape and/or surface area and/or color can be automatically detected by the image evaluation device. The marking of the pantograph extends in the direction of wear, with its position and/or shape and/or surface area and/or color changing with increasing wear. The contact strip has a continuous marking or several markings spaced apart from one another over its working width.

The quality of the recorded video images is often not high enough for automated detection of the closed state of the sliding contact piece to be reliably possible. Rather, it is necessary to resort to visual inspection of the video images by experienced maintenance personnel, which makes detecting the condition of a pantograph time-consuming and costly.

The invention is therefore based on the object of providing a system of the type mentioned at the outset with which status data representing a wear status of sliding contact pieces can be recorded more simply and reliably.

The object is achieved by a generic system with the features specified in the characterizing part of patent claim 1.

A generic system for detecting a state of wear of a pantograph arranged on an electric traction vehicle, which has at least one piece of sliding contact intended for contacting a contact wire of an overhead line system, comprises a sensor device for acquiring status data representing the state of wear of the sliding contact piece. The traction vehicle can be designed as a road or rail vehicle and can be driven electrically or hybrid-electrically. In order to feed in electrical traction energy from a two-pole or one-pole catenary system, the traction vehicle is equipped with a current equipped customer, which has an erectable support linkage, for example in the form of a pantograph-like half scissors or scissors or in the form of erectable rods. The supporting linkage can carry sliding shoes or a contact rocker with elongated sliding strips, which carry a carbon-containing sliding contact piece in order to establish electrical contact for energy transmission with the contact wire or wires. The sliding contact piece in particular is subject to material wear as a result of normal abrasion caused by contact with the contact wire on its upper-side contact surface, as well as breakouts and spalling that occur when contact is made quickly or hard.

This material wear is monitored by a sensor device, for which purpose data representing the state of wear of the sliding contact piece are recorded.

According to the invention, the detection system comprises at least one, ie one or more, reference bodies. Each reference body has a reference surface and is firmly connected to the pantograph in such a way that there is a fixed relative position between the sliding contact piece and the reference surface while the traction vehicle is moving. The reference surface is preferably flat and serves as a comparison level for distance measurements of the sensor device. The sensor device is arranged on the track side and designed to detect a height profile of the sliding contact piece over the reference surface by means of a steerable scanning beam. The sensor device can be arranged, for example, on a measuring portal set up on a route for a traction vehicle, so that the sensor device can direct the scanning beam vertically from above onto sliding contact pieces of passing traction vehicles. The sensor device is preferably set up for electro-optical distance measurement, which detects a distance profile to the object surfaces in its measuring range by propagation time measurement, phase position measurement, triangulation or by a light section method. By scanning the surfaces in the measuring range, a height profile is recorded, in which the reference surface of a reference body serves as a clearly detectable comparison level. An evaluation unit is connected to the sensor device, by means of which the status data of the sliding contact piece can be determined from the recorded height profile. A height profile of the contact surface as the remaining closing reserve of the sliding contact piece, the position of possible fractures in or out of the sliding contact piece or the position of the sliding contact piece as a whole on the pantograph can be obtained as status data. For this purpose, the evaluation unit can be stored as reference data in a memory unit with reference profiles and reference positions of unworn and properly arranged sliding contact pieces. A comparison unit of the evaluation unit can determine the status data of the sliding contact piece by comparing the detected height profiles with the reference data.

In a further advantageous embodiment of the system according to the invention, the reference body is fastened to a carrier profile which fixes the sliding contact piece in place. The reference surface is formed here by a flat surface of the reference body, which protrudes laterally beyond the carrier profile. The reference surface is therefore at the height of the lower edge of the carrier profile. In this embodiment, a reference surface is formed on which designs of carrier profiles with sliding contact pieces can be placed, which have a standardized carrier profile height. The remaining wear reserve of sliding contact piece material thus results from the height profile over the reference surface by subtracting the carrier profile height. If other carrier profile heights are used, they must be stored in the evaluation unit.

In a further advantageous embodiment of the system according to the invention, the reference surface is arranged at the transition from the carrier profile to the sliding contact piece. In this embodiment, the reference body can have two legs which enclose the carrier profile in a U-shape, so that the reference surface formed by the upper sides of the legs is level with the underside of the sliding contact piece. Although this presupposes that, when changing, carrier profiles with sliding contact pieces that are dimensionally compatible with the reference body are always to be used, the height profile and thus the wear reserve of sliding contact piece material results metrologically directly from the difference in the measuring distances between the contact surface of the sliding contact piece and the reference surface.

In a further advantageous embodiment of the system according to the invention, the reference body is fastened to a carrying structure of the current collector that supports the carrier profile. This fastening of the reference body does not unnecessarily increase the mass of the combination of sliding contact piece and carrier profile, which is designed as a sliding strip, for example. As a result, the design or the outer shape of the carrier profile does not have to be specified for attachment of reference bodies. For example, a small and lightweight reference body can be attached directly to the two mounting points of the contact rocker for the carrier profile in order to provide the reference surface required for the scanning measurement.

In a further advantageous embodiment of the system according to the invention, the scanning beam of the sensor device is designed as a laser beam. The sensor device can be designed as a 3D laser cut sensor with a high-frequency scanning line laser. The laser cutting method that can be carried out in this way is known per se, is readily available and has the measurement accuracy required for recording the height profile.

In a further advantageous embodiment of the system according to the invention, the reference body has an identification feature that can be detected by the sensor device. By clearly identifying all reference bodies by the sensor device, the exact locations of damage to a sliding contact piece or other components of the pantograph, for example a contact rocker carrying the sliding contact pieces, can be assigned even more precisely in the lateral direction as status data. In addition, if one of the reference bodies is incorrectly measured, it is not unclear to which position within the pantograph the further recognized reference bodies belong, since the reference bodies can be distinguished from one another on the basis of their identification feature. The identification feature can be formed, for example, by a pattern engraved into the reference surface.

In a further advantageous embodiment of the system according to the invention, the identification feature is formed by an outer contour of the reference body. For example, grooves milled vertically on the side faces of the reference bodies can vary in width and/or spacing in such a way that a pattern of the outer contour that results and can be detected from above by the sensor device uniquely identifies the respective reference body. Such an outer contour is easy to produce.

In a further advantageous embodiment of the system according to the invention, the evaluation unit is designed to determine the lateral position of the height profile based on the lateral position of one or more reference bodies. The local progression of the wear reserve, ie the actually still available material height of the sliding contact piece, is thereby determined as additional status data. Furthermore, the position, in particular of local breakouts or spalling of sliding contact piece material—for example, from its front or rear edge—can be determined as state data by comparing the position with the reference bodies.

In a further advantageous embodiment of the system according to the invention, the evaluation unit is designed to determine the lateral position of the sliding contact piece using the lateral position of one or more reference bodies. The detected actual lateral position of the sliding contact piece compared to a desired lateral position stored in the evaluation unit form important status data that can provide information about a possible incorrect position of the sliding contact piece. This principle can also be applied to other parts and components in the detection area of the sensor device, so that misalignments or a complete absence of these parts or components can be detected.

In a further advantageous embodiment of the system according to the invention, the evaluation unit is designed to determine the lateral position of the contact wire relative to the sliding contact piece. Where the contact wire rests on the sliding contact piece, the recorded height profile shows a significant increase in width and height of the contact wire compared to the contact surface of the sliding contact piece. From the known installation locations of the reference bodies and from their known positions relative to the longitudinal center of the vehicle on the one hand and on the other hand from the lateral position of the contact wire relative to the sliding contact piece, the current position of the traction vehicle relative to the contact wire(s) of the overhead line system can be obtained as additional information. The relative position information can be used for steering interventions, in particular in the case of non-track-bound traction vehicles, such as road vehicles, in order not to lose contact with the contact wires.

The invention also relates to a current collector for an electric traction vehicle according to claim 11, which has at least one sliding contact piece provided for electrically contacting a contact wire of an overhead line system and a system for detecting a state of wear according to one of claims 1 to 10.

The invention also relates to a traction vehicle with a pantograph according to claim 12.

• 1 eine Seitenansicht eines Triebfahrzeugs mit einem eine Oberleitungsanlage kontaktierenden Stromabnehmer,
• 2 eine perspektivische Ansicht des Stromabnehmers aus 1,
• 3 eine Frontansicht einer Schleifleiste des Stromabnehmers aus 2,
• 4 eine Draufsicht der Schleifleiste aus 3,
• 5 ein Querschnitt durch die Schleifleiste aus 2,
• 6 eine Frontansicht einer unter einer Sensoreinrichtung befindlichen Schleifleiste,
• 7 ein Querschnitt durch die Schleifleiste aus 2 mit einem Bezugskörper einer ersten Ausführung,
• 8 ein Querschnitt durch die Schleifleiste aus 2 mit einem Bezugskörper einer zweiten Ausführung,
• 9 eine perspektivische Darstellung einer für einen Bezugskörper an einer Schleifleiste vorgesehenen Befestigungsstelle,
• 10 eine Draufsicht auf eine Kontaktwippe des Stromabnehmers mit zwei Schleifleisten und vier Bezugskörpern, und
• 11 eine perspektivische Darstellung eines Bezugskörpers

Further advantages and properties of the invention result from the following description of exemplary embodiments with reference to the drawings, in which

• 1 a side view of a traction vehicle with a pantograph contacting an overhead line system,
• 2 a perspective view of the pantograph 1 ,
• 3 a front view of a contact strip of the pantograph 2 ,
• 4 a top view of the contact strip 3 ,
• 5 a cross-section through the contact strip 2 ,
• 6 a front view of a contact strip located under a sensor device,
• 7 a cross-section through the contact strip 2 with a reference body of a first embodiment,
• 8th a cross-section through the contact strip 2 with a reference body of a second embodiment,
• 9 a perspective view of an attachment point provided for a reference body on a contact strip,
• 10 a top view of a contact rocker of the pantograph with two contact strips and four reference bodies, and
• 11 a perspective view of a reference body

are illustrated schematically.

According to 1 an electric traction vehicle 1 designed, for example, as a semitrailer tractor drives on a roadway 2 along which an overhead line system for providing electrical energy for the traction vehicle 1 is installed. The overhead contact line system has contact wires 3 running above an electrified lane of the roadway 2, which are suspended in a manner known per se via hangers 4 on carrying cables 5. Due to the rubber-tired vehicle wheels 6 of the traction vehicle 1 insulating against earth, the overhead line system is of two-pole design, ie has two contact wires 3 running next to one another and designed as forward and return conductors. The traction vehicle 1 comprises an electric or hybrid electric traction drive 7, for whose supply of traction energy a current collector 8 is provided, which is supported on the vehicle frame 10 via its main frame 9, for example.

With additional reference to 2 the current collector 8 has an erectable support linkage with a lower arm 11 and an upper arm 12 articulated thereto. The lower arm 11 is supported on the vehicle side on a base joint 13, while the upper arm 12 on the contact wire side carries a contact rocker 14 with two contact strips 15 arranged one behind the other in the longitudinal direction X of the vehicle. The elongate contact strips 15 extend in the vehicle transverse direction Y and are equipped at their lateral ends with discharge horns 16 bent downwards. The support linkage can be set up by means of a lifting device 17 designed as an air bellows, as a result of which the contact strips 15 move from a lower rest position to an upper contact position according to FIG 1 can be raised along a vehicle vertical direction Z. In order to parallelly raise the contact plane defined by the contact strips 15, the current collector 8 comprises a known parallel guide linkage made up of tie rods 18 and coupling rods, not shown in detail, which articulately connect the lower arm 11 to the contact rockers 14. In the contact position, the contact strips 15 of a contact pole are pressed against the associated contact wire 3 to produce an electrical contact.

Each contact strip 15 includes according to 3 until 5 an elongated sliding contact piece 19 made of an electrically conductive, mostly carbon-containing material, which is fixed on a carrier profile 20. The carrier profile 20 can be designed as an aluminum hollow profile. The sliding contact piece 19 can according 5 have a rectangular cross-section over its entire length, which in new, unworn condition is higher in a central working area and slopes flatly towards both lateral ends. The sliding contact piece 19 has an upper side 21 which faces the contact wire 3 during vehicle operation and which forms the contact surface with the contact wire 3 . A front side 22 of the sliding contact piece 19 shows in the vehicle longitudinal direction X of the traction vehicle 1 in the direction of travel, and a rear side 23 of the sliding contact piece 19 opposite the direction of travel. Top 21 and front 22 abut at a front edge 24 of the sliding contact piece 19, top 21 and back 23 at a rear edge 25 of the sliding contact piece 19. Front edge 24 and rear edge 25 are according to 5 slightly rounded.

The material wear of the sliding contact piece 19 that occurs during operation of the traction vehicle 1, but also a misalignment of the sliding contact piece 19, are compensated for by a system 30 according to the invention 6 until 11 recorded. The detection system 30 has at least one reference body which, in the embodiment according to FIG 7 reference numeral 33 and in the embodiment according to FIG 8th carries the reference number 34. In the illustrated embodiment according to 10 four reference bodies 34a, 34b, 34c and 34d are provided. Each reference body 33, 34, 34a to 34d has a reference surface 35 and is firmly connected to the pantograph 8, so that there is a fixed relative position between the sliding contact piece 19 and the reference surface 35 while the traction vehicle 1 is moving. The reference surface is flat and serves as a comparison level for distance measurements of the sensor device 31.

According to 9 and 10 the reference bodies 34a to 34d are fastened to a supporting structure of the current collector 8 supporting the carrier profile 20 . The contact rocker 14 of the current collector 8 serves as the supporting structure. The four profile mounts 27 attached to the rocker box 26, on which the carrier profiles 20 of the contact strips 15 are fixed, are particularly suitable for fastening the reference bodies 34a to 34d. The attachment points are in 9 shown without reference body 34a to 34d for better visibility. The reference bodies 34a to 34d are attached to the profile mounts 27 so that a contact strip 15 mounted on two reference bodies 34a and 34b or 34c and 34d can be changed without the reference bodies 34a to 34d having to be dismantled.

A sensor device 31 of the detection system 30 is arranged, for example, on a trackside measuring portal, which can be set up before the start of an electrified track section with contact wires 3 but also at suitable measuring points on the track section. A measuring portal can span the entire roadway like a bridge or be formed by a lateral mast with a cantilever. The sensor device 31 is preferably designed as a laser scanner with a steerable scanning beam 32 formed by a laser beam. However, other electro-optical sensor devices with a steerable scanning beam are also suitable. The laser scanner is a 3D laser cut sensor with a high-frequency scanning line laser, by means of which a height profile of the sliding contact piece 19 above the reference surface 35 can be recorded. For this purpose, the sensor device 31 according to FIG 1 arranged above the roadway 2 in order to direct its scanning beam 32 vertically from above onto sliding contact pieces 19 of passing locomotives 1. If necessary, several sensor devices 31 are arranged on a measuring portal in order to detect all sliding contact pieces 19 of a traction vehicle 1 .

The measuring range of the sensor device 31 is according to FIG 6 at a measuring range distance D of about 500 mm above the sliding contact piece 19 to be scanned. The lateral pivoting range of the scanning beam 31 at the height of the sliding contact piece 19 and thus the measuring range width B is about 1200 mm. The laser beam 31 is designed for a measuring range height of about 100 mm, within which the wear reserve V of a sliding contact piece 19, which is about 30 mm, lies. The laser beam 31 scans the upper side 21 of the sliding contact piece 19 and the reference surface 35 of the reference body 33 7 respectively 34 according to 8th one after the other cutting planes that lie one behind the other in the vehicle longitudinal direction X. A reflection point R of the scanning beam 32 is indicated by a small circular area from some of the sectional planes. Each cutting plane leads to a contour line and the sum of all contour lines to a height profile.

According to 7 the reference body 33 is designed as a plate which protrudes laterally beyond the carrier profile 20 . The reference surface 35 is formed by the plane surface of the plate. The reference surface 35 is thus at the height of the lower edge of the carrier profile 20. The remaining wear reserve V of sliding contact piece material is thus obtained from the height profile h above the reference surface 35 by subtracting the carrier profile height p. According to 8th the reference surface 35 of the U-shaped reference body 34 is arranged at the transition from the carrier profile 20 to the sliding contact piece 19 . The height profile h and thus the wear reserve V of the sliding contact piece material results from the measurement technology directly from the difference in the measuring distances between the upper side 21 of the sliding contact piece 19 and the reference surface 35.

According to 10 the reference bodies 34a to 34d each have an identification feature that can be detected by the sensor device 31 and is formed by an individual outer contour 36 of the reference body 34a to 34d. For example, the reference body 34a to 34d according to 10 have vertically milled grooves that vary in width and/or spacing in such a way that a pattern of the outer contour 36 that is created as a result and that can be detected from above by the sensor device 31 clearly identifies the respective reference body 34a to 34d. An identification feature that is just as easy to produce can be provided in accordance with 11 by transversely milled grooves in the legs of a U-shaped reference body 34 (see 8th ) be formed, which is caused by varying the width and spacing of the grooves. The sensor device 31 recognizes the respective reference body 34 based on the individual course of the contour lines in the area of the reference surfaces 35. Due to the fact that the reference bodies 34a to 34d can be distinguished from the point of view of the sensor device 31, the exact locations of damage to a sliding contact piece 19 or other components can be used as status data of the current collector 8, for example a contact rocker 14 carrying the sliding contact pieces 19, can be assigned even more precisely in the lateral or lateral direction.

According to the invention, an evaluation unit 37 is connected to the sensor device 31, by means of which the status data of the sliding contact piece 19 can be determined from the recorded height profile h. A height can be used as status data course of the contact surface 21 and from this the remaining closing reserve of the sliding contact piece 19, the position of possible fractures in or out of the sliding contact piece 19 or the position of the sliding contact piece 19 as a whole on the current collector 8 can be obtained. For this purpose, the evaluation unit 37 can have a memory unit (not shown) with reference profiles and reference positions of unworn and properly arranged sliding contact pieces 19 as reference data. A comparison unit, also not shown, of the evaluation unit 37 can determine the status data of the sliding contact piece 19 by comparing the detected height profiles h with the reference data.

The evaluation unit 37 is designed in particular to determine the lateral position of the height profile h using the lateral position of one or more reference bodies 33, 34, 34a to 34d. The local progression of the wear reserve V, ie the actual still available material height of the sliding contact piece 19, is determined as additional status data. Furthermore, the position of local breakouts or spalling of sliding contact piece material--for example from its front edge 24 or rear edge 25--can be determined as state data by comparing the position with the reference bodies 33, 34, 34a to 34d.

The evaluation unit is also designed in particular to determine the lateral position of the sliding contact piece 19 using the lateral position of one or more reference bodies 33, 34, 34a to 34d. The detected actual lateral position of the sliding contact piece 19 compared to a desired lateral position stored in the evaluation unit 37 form important status data that can provide information about a possible incorrect position of the sliding contact piece 19. This principle can also be applied to other parts and components in the detection area of the sensor device 31, so that incorrect positions or a complete absence of these parts or components can be detected.

The evaluation unit 31 is also designed in particular to determine the lateral position of the contact wire 3 relative to the sliding contact piece 19 . Where the contact wire 3 rests on the sliding contact piece 19 , the recorded height profile h shows a significant increase in width and height of the contact wire 3 compared to the contact surface 21 of the sliding contact piece 19 . From the known installation locations of the reference bodies 33, 34, 34a to 34d and from their known positions relative to the longitudinal center of the vehicle on the one hand and on the other hand from the lateral position of the contact wire 3 relative to the sliding contact piece 19, the instantaneous position of the traction vehicle 1 relative to the contact wire(s) can be obtained as additional information 3 of the catenary system.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102009006392 A1 [0003]
• WO 2015007718 A2 [0004]

Claims (12)

System (30) for detecting the state of wear of a pantograph (8) arranged on an electric traction vehicle (1), which pantograph has at least one sliding contact piece (19) provided for contacting a contact wire (3) of an overhead line system, comprising a sensor device for detecting the state of wear of the Status data representing the sliding contact piece (19), characterized by - at least one reference body (33, 34, 34a to 34d) having a reference surface (35), which is firmly connected to the pantograph (8) in such a way that while the traction vehicle (1) is moving there is a fixed relative position between the sliding contact piece (19) and the reference surface (35), - the sensor device (31) being arranged on the track side and designed to use a steerable scanning beam (32) to record a height profile (h) of the sliding contact piece (19) above the reference surface (35) to detect, and - with the sensor device (31) an evaluation processing unit (37) is connected, by means of which the status data of the sliding contact piece (19) can be determined from the recorded height profile (h). system (30) after claim 1 - wherein the reference body (33, 34, 34a to 34d) is attached to a carrier profile (20) which fixes the sliding contact piece (19) in place. system (30) after claim 2 - The reference surface (35) being arranged at the transition from the carrier profile (20) to the sliding contact piece (19). System (30) according to any one of the preceding claims, - Wherein the scanning beam (32) of the sensor device (31) is designed as a laser beam. System (30) according to any one of the preceding claims, - The reference body (33, 34, 34a to 34d) being fastened to a supporting structure (14) of the current collector (8) supporting the carrier profile (20). System (30) according to any one of the preceding claims, - wherein the reference body (33, 34, 34a to 34d) has an identification feature that can be detected by the sensor device (31). system (30) after claim 6 - wherein the identification feature is formed by an outer contour (36) of the reference body (34a to 34d). System (30) according to any one of the preceding claims, - The evaluation unit (37) being designed to determine the lateral position of the height profile (h) based on the lateral position of one or more reference bodies (34a to 34d). System (30) according to any one of the preceding claims, - The evaluation unit (37) being designed to determine the lateral position of the sliding contact piece (19) based on the lateral position of one or more reference bodies (34a to 34d). System (30) according to any one of the preceding claims, - The evaluation unit (37) being designed to determine the lateral position of the contact wire (3) relative to the sliding contact piece (19). Current collector (8) for an electric traction vehicle (1), having - at least one sliding contact piece (19) provided for contacting a contact wire (3) of an overhead line system and - A system (30) for detecting a state of wear according to any one of the preceding claims. Traction vehicle (1) with a pantograph (8) according to the preceding claim.

Images