METHOD FOR CONDITION ASSESSMENT OF A ROAD-SIDE OVERHEAD LINE SYSTEM

Description

[0001] The invention relates to a method for recording status data of an electrical overhead line system installed along a road section.

[0002] Such a method is disclosed, for example, in US 2019 / 392225 A1.

[0003] Overhead line systems for supplying electrically powered vehicles with traction energy while in motion have long been known for rail vehicles, but have recently also been tested for road vehicles. The vehicle has a pantograph which, for energy transfer, is in sliding contact with the contact wire of a single-pole overhead line system in a rail vehicle and with the contact wires of a two-pole overhead line system in a road vehicle. Due to the fixed track connection of a rail vehicle, condition data of the overhead line system, such as the position and wear of contact wires, are recorded vertically relative to the rail head plane and laterally relative to the rail center plane for rail-mounted measuring vehicles. For road-side overhead line systems, condition data must be measured manually, which has the disadvantage that the road section can only be used to a limited extent during the measurement.

[0004] Patent DE 10 2017 214 479 B3 discloses a method for acquiring and updating route data stored in a transponder. The route data includes a relative position between a lane for a motor vehicle and an overhead line vertically spaced from the lane. The motor vehicle has a pantograph, which is brought into sliding contact with the overhead line connected to a power grid to transmit electrical energy for propulsion. The transponder is arranged on a mast supporting the overhead line. The current route data is read by a reading device of the motor vehicle as the transponder passes and used by a driver assistance system to adjust the pantograph to an optimal position for maintaining the sliding contact and / or to ensure that the pantograph is reliably attached to the overhead line.To record the route data, a measuring vehicle is provided, to which a measuring system with a measuring device and an evaluation unit is attached. The measuring devices consist of a camera for measuring the lane and a lidar for measuring the position of the overhead line. With the help of a further relative position between the camera and lidar, the evaluation unit determines the relative position between the lane and the overhead line. The measuring vehicle has a writing device for transmitting the current route data to the transponder. The evaluation unit compares the current route data obtained from the measured data with the route data stored and read out in the transponder. If a difference is detected, the current route data is provided to the writing device for transmission to the transponder.

[0005] German Patent Application DE 10 2020 207 963 A1 discloses a method for monitoring the condition of an overhead line system arranged along a roadway. The overhead line system comprises an overhead line extending above the roadway to supply power to an electrically or hybrid-electrically powered road vehicle using the roadway. This overhead line can be contacted by a pantograph of the roadway to supply power. Using an image recording system with at least one video camera installed in the area of ​​the roadway, video data representing at least a portion of the overhead line system is captured. The actual condition of the overhead line system is determined from the captured video data.Using at least one thermal imaging camera of the image recording system installed in the roadway area, thermal image data is acquired that represents at least a section of the overhead line system. The actual status of the overhead line system is determined from the acquired thermal image data. The acquired video image data and thermal image data are transmitted to an image playback system in a monitoring center, where the transmitted video image data and thermal image data are displayed on a screen of the image playback system to determine the actual status of the overhead line system. The acquired video image data and thermal image data are transmitted to an image evaluation system for automated image analysis, where the transmitted video image data and thermal image data are analyzed using trained image evaluation algorithms to determine the actual status of the overhead line system.Using image analysis algorithms, a deviation between the determined actual state of the overhead line system and the target states of the overhead line system stored in a database of the image analysis system is calculated. The database contains target states of the overhead line system for various operating parameters, such as current, voltage, or power in the overhead line or in a substation of the overhead line system, and for various environmental parameters, such as air temperature, wind speed, or the like. The target states of the overhead line system used to determine the deviation are selected depending on the measured operating and environmental parameters. The actual state is determined as a rest position and a vibration behavior of line components of the overhead line system, in particular catenaries, cross-support structures, suspension columns, tensioning devices, section insulators, and masts of the overhead line system.Based on the determined actual condition and the determined deviation of the actual condition from one of the target conditions, a status message is automatically triggered about detected wear or a detected fault.

[0006] Due to the lack of knowledge or inaccuracy of the exact measuring positions of the measuring vehicle from which the condition data of the overhead line system is recorded, the known methods are not suitable for automated comparison with historical condition data, such as those stored in a transponder in the case of DE 10 2017 214 479 B3 or in a database in the case of DE 10 2020 207 963 A1. The invention is therefore based on the object of providing a generic method that overcomes the disadvantages of the prior art.

[0007] The method mentioned above is designed and intended for recording status data from an electrical overhead line system installed along a road section. The overhead line system can be contacted for energy transmission by a pantograph of an electrically or hybrid-electrically powered road vehicle traveling along the road section. The overhead line is designed as a two-pole system, and each contact pole has a chain system consisting of supporting cables and contact wires suspended from masts erected at the side of the roadway. The chain systems are held above an electrified lane of the roadway by means of outriggers attached to the masts, so that the pantograph of a road vehicle traveling along the lane can be brought into sliding contact with the contact wires.For this purpose, the current collector can be designed as a pantograph, which can be moved from a lowered rest position to a raised contact position by means of a lifting device and pressed against the contact wires. Substations supply the feeder sections of the overhead line system with the desired voltage, preferably direct current. Using a sensor device on a measuring vehicle traveling along the road, three-dimensional position data of environmental points representing the vehicle's surroundings are recorded at measuring positions. The position data of an environmental point, for example, a contact wire point of the overhead line system, indicates the position of the environmental point in a three-dimensional sensor coordinate system.

[0008] According to the invention, the location coordinates of the measurement positions are additionally determined using a satellite-based positioning device on the measuring vehicle. Receivers of the Global Positioning System (GPS) or comparable systems are suitable as the positioning device, allowing the measurement positions to be determined with an accuracy of approximately 30 m ± 10 m. The location coordinates can be determined from the geographical coordinates, i.e., the geographical longitude and latitude, of the GPS receiver carried on board the measuring vehicle and located at the measurement position in the WGS84 reference system (World Geodetic System 1984).

[0009] By assigning the spatial coordinates of a measurement position to the position data recorded at that measurement position, an environmental point cloud is generated with geocoordinates of the recorded environmental points. Environmental points can, for example, be located on boundary surfaces as well as their edges, corners, or other boundary lines of environmental objects that reflect radiation pulses emitted by the sensor device. Sensor devices can include, for example, one or more Lidar sensors (Light Detection and Ranging), Time-of-Flight cameras, or Radar sensors (Radio Detection and Ranging). Position data from the environmental points is recorded in the sensor coordinate system, for example, in polar coordinates characterized by distance, azimuthal, and polar angle.The surrounding objects that can be detected from a measuring position are thus represented by a dense surrounding point cloud, the geocoordinates of which are formed by assigning the location coordinates of the measuring position to the sensor-detected position data of the surrounding points.

[0010] Using an object recognition system, one or more stationary reference objects present in the vehicle's surroundings with known reference coordinates and one or more overhead line system objects present in the vehicle's surroundings are recognized from the geocoordinates of the generated environmental point cloud. The object recognition system can, for example, be formed by a trained artificial intelligence. Known system and reference objects serve as training data, which are recognized by computer-based vision based on the geocoordinates in a captured environmental point cloud. The reference objects are stationary, clearly identifiable objects, such as conspicuous structures or other landmarks, whose reference coordinates are known to within approximately 5 cm to 50 cm.

[0011] The deviation of the geocoordinates of the surrounding points assigned to a detected reference object from its reference coordinates is determined, and the geocoordinates of surrounding points in the surrounding point cloud are corrected by the determined deviation. This correction significantly improves the accuracy of the geocoordinates – by up to a factor of 100. Using the object recognition system, status data of the system objects is determined from the corrected geocoordinates of the system objects. The high accuracy of the corrected geocoordinates forms the basis for an automated comparison of currently recorded status data of the overhead line system, for example, with predefined target status data or with previously recorded status data.

[0012] In an advantageous embodiment of the method according to the invention, status data of a system object is determined by comparing the corrected geocoordinates of the system object with predefined target status data of the system object. Predefined target status data of system objects of the overhead line system can contain, for each measurement position, geocoordinates of the system objects that can be detected by sensors at the respective measurement position, which are defined, for example, by planning data for the construction of the overhead line system. As status data of system objects, for example, geocoordinates of masts, contact wire positions, tensioning device positions, and the like can be considered.

[0013] In a further advantageous embodiment of the method according to the invention, status data of a system object are determined by comparing the corrected geocoordinates of the system object with corrected geocoordinates of this system object recorded during a previous measurement run. The reference coordinate-based correction of the geocoordinates of system objects allows status data of a system object at a measurement position to be compared with each other, which were obtained from different measurement runs. This allows changes in the positions and shapes of system objects, for example, the sag and wear pattern of a contact wire, to be determined.

[0014] In a further advantageous embodiment of the method according to the invention, one or more road marking objects of the road section are recognized by the object recognition device from the geocoordinates of the generated environmental point cloud. The corrected geocoordinates of the road marking objects are used as a reference line for the status data of the system objects. Road markings applied to the roadway, such as side or center lines delimiting the electrified lane, form low-level material steps at their edges, the position data of which can be detected by sensors. Similar to the track center in rail transport, the status data of system objects determined at a measurement position can be related to the road marking.For example, the lateral positions of the contact wires relative to the side line of the electrified lane or the contact wire heights above lane level can be specified and compared with condition data from other test runs.

[0015] In a further advantageous embodiment of the method according to the invention, masts of the overhead line system and / or bridges spanning the road and / or restraint systems of the road are identified as reference objects. Load-bearing structural elements of the overhead line system, such as their masts, but also infrastructure facilities along the road, such as bridge structures, restraint systems, and road signs and their masts, are virtually immobile and have well-known locations, making them particularly suitable as reference objects. The coordinates of prominent and easily detectable corners, edges, or boundaries of these reference objects are used, in particular, as their reference coordinates.

[0016] In a further advantageous embodiment of the method according to the invention, a position and / or wear and / or defect and / or loss of an object of the overhead line system is determined as status data. With the corrected geocoordinates of the surrounding points, the surrounding point cloud represents a digital image or a digital twin of the object at a measuring position with high positional accuracy. From this, for example, the heights of contact wires above roadway level and their lateral positions relative to a center of the electrified lane can be determined as the position status at a measuring position. Likewise, the vertical thickness of contact wires and / or the width of the contact surface on the underside of the contact wires can be recorded as the wear status of the contact wires at the respective measuring position.Dimensional and position-related defects in system components, such as broken contact wires or deformed section insulators, tensioning devices, or other components of the overhead line system, can also be detected. Furthermore, it can also be determined whether a system component installed at a measuring position is completely missing because it was torn off by defective pantographs from passing road vehicles or by fallen trees.

[0017] In a further advantageous embodiment of the method according to the invention, video data and / or thermal image data and / or electromagnetic field data from system objects of the overhead line system are recorded at measurement positions using one or more sensor units of the measuring vehicle and referenced with the location coordinates corrected for the determined deviation. The referenced sensor data are taken into account when determining the status data. Using such sensor units on the measuring vehicle, in addition to the position data recorded by the sensor device, further sensor data describing the current status of system objects can be collected at measurement positions.By correcting the location coordinates determined for these measurement positions by the determined deviation between the geocoordinates of the surrounding points assigned to a detected reference object and its reference coordinates, highly accurate, corrected location coordinates can be assigned to the sensor data as a reference. Such location-referenced sensor data, in turn, forms the basis for an automated comparison of status data obtained from the sensor data. A sensor unit in the form of a video camera can record images of system objects as video data at measurement positions, from which status data of the system objects, such as defects or losses, can be obtained using image analysis algorithms. Another sensor unit in the form of a thermal camera can record thermal image data of system objects at measurement positions, from which, for example, the current contact wire temperatures can be obtained as status data.Another sensor unit in the form of a field strength measuring device can measure field strength data of an electromagnetic field surrounding the contact wires at measuring positions, from which status data of these system objects can also be obtained.

[0018] In a further advantageous embodiment of the method according to the invention, the weather conditions prevailing at the respective measuring positions during the measurement run are taken into account when determining the condition data. The prevailing weather conditions at a measuring position can include ambient temperature, wind force and direction, precipitation, and similar factors that influence the current condition of system objects. Thus, temperature, wind, and ice cover determine the position data of contact wires, which must be taken into account when comparing with predefined target condition data or with previously recorded condition data to avoid evaluating the current condition of the contact wires as faulty due to weather-related effects.The weather data can be determined directly from the measuring vehicle using additional sensors or can be obtained via a wireless communication connection from trackside sensors or from a centrally maintained database.

[0019] In a further advantageous embodiment of the method according to the invention, road vehicles traveling ahead or following behind with pantographs contacting the overhead line are taken into account when determining the condition data. In sliding contact, pantographs are pressed against a contact wire from below with a pressure force, which locally leads to a lifting of the contact wire around the road vehicle. To determine the actual contact wire height at a measuring position of the measuring vehicle, the lifting of the contact wire by road vehicles traveling ahead or behind the measuring vehicle at a distance with a lifting effect on the measuring position, and possibly by the measuring vehicle itself, is taken into account. This allows for a constant comparison of condition data that has been adjusted for lifting effects caused by pantographs contacting the contact wire.For this purpose, the measuring vehicle can receive the current location coordinates of road vehicles with wired pantographs traveling along the road route directly from these road vehicles via a wireless communication link.

[0020] In a further advantageous embodiment of the method according to the invention, the determined status data are evaluated with regard to a repair or maintenance requirement. If a repair or maintenance requirement is identified, a repair or maintenance order is automatically triggered, specifying the name and location of the affected system object. The status data of system objects determined for a measuring position can be automatically evaluated for a repair or maintenance requirement in a vehicle-based or central evaluation device. If the status data show that, for example, the position of a contact wire needs to be corrected at a measuring position or a defective or missing system object needs to be replaced, a corresponding order can be automatically triggered, specifying where which service work needs to be carried out, which significantly simplifies the maintenance of the overhead line system.

[0021] Further advantages and features of the invention will become apparent from the following description of an embodiment with reference to the drawings, in which FIG 1 a measuring vehicle with a measuring system for carrying out the condition determination method according to the invention and FIG 2 a flow diagram of the condition determination method according to the invention are illustrated schematically.

[0022] FIG 1 shows a plan view of a road section SS with one lane FS, for example the right lane of a motorway or expressway. An electrical overhead line system 10 is installed along the road section SS to electrify the lane FS. The overhead line system 10 comprises a variety of system objects. These include masts 11 erected to the side of the lane FS with booms 12 projecting above the lane FS. Two parallel catenaries are suspended from the booms 12, each having a contact wire 13 connected to a suspension cable via hangers and guyed at their ends by tensioning devices. The two contact wires 13 form the forward and return conductors of the two-pole overhead line system 10, via which electrical energy fed in from a substation is provided for road vehicles 20 with electric drive, in particular heavy goods vehicles and buses.For energy extraction, the road vehicles 20 have a pantograph-like current collector 21, for example, whose contact strips 23 can be raised by means of a lifting device from a lowered rest position to an upright contact position and pressed against the contact wires 13. For this purpose, the contact wires 13 run parallel to each other and symmetrically to a longitudinal center plane of the lane FS and at the same height above the roadway. For energy transfer during travel, the contact strips 23 of the upright current collector 21 and the contact wires 13 are in sliding contact with each other.

[0023] To achieve high availability of the overhead line system 10 and to avoid damage or accidents to road vehicles 20 using the overhead line system 10, according to the invention, a condition of the overhead line system 10 is determined at measuring positions MP along the road section SS. For this purpose, a measuring vehicle 30 with a measuring system 40 is provided, which travels along the road section SS. The measuring system 40 comprises a plurality of sensors for data acquisition, which are arranged predominantly on the vehicle side, but partly also on the track side. A sensor device 41, designed for example as a lidar, is arranged on the measuring vehicle 30, which scans a vehicle environment UMP detectable from the measuring position MP in order to obtain three-dimensional position data LD of environmental points UP of the vehicle environment UMP.Furthermore, a satellite-based positioning device 42, embodied, for example, as a GPS receiver, is arranged on the measuring vehicle 30 to determine the location coordinates OK of the measurement position MP. By assigning the location coordinates OK to the position data LD, a dense environmental point cloud UPW with geocoordinates GK of the detected environmental points UP is generated, which represents environmental objects of the vehicle environment UMP. Furthermore, an object recognition device 43 for recognizing environmental objects from the geocoordinates GK of the generated environmental point cloud UPW is arranged on the measuring vehicle 30, for example, formed by a trained artificial intelligence. In particular, stationary reference objects RO1, RO2, RO3 present in the vehicle environment UMP with known, highly accurate reference coordinates RK and system objects 11, 12, 13 of the overhead line system 10 present in the vehicle environment UMP are recognized.Fixed, clearly identifiable objects, such as signposts RO1, bridge bases RO2, restraint systems RO3, and the like, serve as reference objects. The geocoordinates GK of the surrounding points UP assigned to a detected reference object RO1, RO2, RO3 are then compared with its reference coordinates RK, and a possible deviation ΔGR is determined. This serves as a correction value for the geocoordinates GK, which were determined based on the comparatively inaccurate location coordinates OK of the measurement position MP.Using the object recognition device 43, status data ZD of the overhead line system 10 is determined from the thus corrected geocoordinates GK' of the system objects 11, 12, 13. This is done, for example, by comparing the corrected geocoordinates GK' of the system object 11, 12, 13 with predefined target status data ZD! known from the planning data of the overhead line system 10 or with corrected geocoordinates GK'* of this system object recorded in a previous measurement run. Status data ZD can be determined, for example, as a position and / or wear and / or defect and / or loss of a system object 11, 12, 13 of the overhead line system 10.By means of the object recognition device 44, road marking objects of the road section SS, such as the side line FO1 and center line FO2 delimiting the electrified lane FS, are also recognized from the surrounding point cloud UPW, the corrected geocoordinates GK' of which can be used as a reference line for the status data ZD of the system objects 11, 12, 13.

[0024] Also arranged on the measuring vehicle 30 are a sensor unit 45 designed as a video camera for acquiring video data VD, a sensor unit 46 designed as a thermal camera for acquiring thermal image data TD, and a sensor unit 47 designed as a field measuring device for acquiring electromagnetic field data from installation objects 11, 12, 13 of the overhead line system 10. The acquired video data VD, thermal image data TD, and field data FD receive the location coordinates OK corrected by the deviation ΔGR as a reference in order to also obtain status data ZD of the installation objects 11, 12, 13, which are reflected in their position or temperature or the strength of an electromagnetic field surrounding them.

[0025] A sensor device 48 that records weather data WD can be arranged alongside the road section SS. This sensor device measures, for example, ambient temperature, wind speed and direction, precipitation, and the like. The weather data WD can be wirelessly transmitted from the sensor device 48 to the measuring vehicle 30 via a communication device 49 of the measuring vehicle 30 in order to be taken into account when determining the condition of system objects 11, 12, 13. The communication device 49 can also receive location coordinates from road vehicles 20 also traveling along the road section SS. These coordinates are determined by a positioning device 22 of the road vehicle 20 and transmitted via a communication device 29 of the road vehicle 20.Due to the distance from the measuring vehicle 30 resulting from the comparison of the location coordinates, a lifting effect on the contact wires 13 by the pantograph 21 of the road vehicle 20 can be taken into account when determining the condition data ZD.

[0026] In an evaluation device 44 of the measuring vehicle 30, the determined condition data ZD are evaluated for repair or maintenance needs. If such a need is diagnosed, a repair or maintenance order RW can be automatically triggered, specifying the name and location of the affected system object 11, 12, 13.

[0027] The method 100 according to the invention for detecting the condition of an overhead line system 10 comprises FIG 2a plurality of method steps, while a measuring vehicle 30 with measuring system 40 travels along a road section SS. By means of the sensor device 41, three-dimensional position data LD of environmental points UP representing a vehicle environment UMP are recorded at measuring positions MP in a step 101. In a step 102, location coordinates OK of the measuring positions MP are determined by means of the satellite-supported position determination device 42. In a step 108, an environmental point cloud UPW with geocoordinates GK of the recorded environmental points UP is generated by assigning the location coordinates OK of a measuring position MP to the position data LD recorded at this measuring position MP.By means of the object recognition device 43, one or more stationary reference objects with known reference coordinates RK present in the vehicle environment UMP, for example, signposts RO1, bridge bases RO2, restraint systems RO3 of the road section SS, are recognized from the geocoordinates GK of the generated environmental point cloud UPW in a step 109, and one or more system objects of the overhead line system 10 present in the vehicle environment UMP, for example, masts 11, booms 12, contact wires 13 and the like, are recognized in a step 110. In a step 112, a deviation ΔGR of the geocoordinates GK of the environmental points UP assigned to a recognized reference object RO1, RO2, RO3 from its reference coordinates RK is determined, and in a step 113, the geocoordinates GK of all environmental points UP of the environmental point cloud UPW are corrected by the determined deviation ΔGR.By means of the object recognition device 43, in a step 115, status data ZD of the plant objects 11, 12, 13 are determined from the corrected geocoordinates GK' of the plant objects 11, 12, 13, for example a position and / or wear and / or a defect and / or a loss of plant objects 11, 12, 13.

[0028] Step 115 includes several subordinate steps 115.n, n = 1, ..., 6. In step 115.1, status data ZD of a plant object 11, 12, 13 is determined from a comparison of the corrected geocoordinates GK' of the plant object 11, 12, 13 with predefined target status data ZD! of the plant object 11, 12, 13. In step 115.2, status data ZD of a plant object 11, 12, 13 is determined from a comparison of the corrected geocoordinates GK' of the plant object 11, 12, 13 with corrected geocoordinates GK'* of this plant object 11, 12, 13 recorded in a previous measurement run.

[0029] In a step 115.6, the corrected geocoordinates GK' of road marking objects FO1, FO2 are used as a reference line for the status data ZD of system objects 11, 12, 13. For this purpose, in a step 111, the road marking objects FO1, FO2 of the road section SS were recognized from the geocoordinates GK of the generated environmental point cloud UPW using the object recognition device 43.

[0030] In a step 115.3, further location-referenced sensor data are taken into account when determining the status data ZD. For this purpose, in a step 103, video data from system objects 11, 12, 13 of the overhead line system 10 are recorded at measuring positions MP using a sensor unit 45 designed as a video camera. In a step 104, thermal image data from system objects 11, 12, 13 of the overhead line system 10 are recorded at measuring positions MP using a sensor unit 46 designed as a thermal camera. In a step 105, electromagnetic field data FD for system objects 11, 12, 13 of the overhead line system 10 are recorded at measuring positions MP using a sensor unit 47 designed as a field measuring device. In a step 114, the acquired video data VD and / or thermal image data TD and / or electromagnetic field data FD are referenced with the location coordinates OK corrected by the determined deviation ΔGR.

[0031] In a step 115.4, the weather conditions prevailing at the respective measuring positions MP during the measurement run are taken into account when determining the condition data ZD. For this purpose, in a step 106, weather data WD applicable to the measuring position MP, such as ambient temperature, wind speed and direction, as well as precipitation, are recorded using a sensor device 48 designed as a weather station.

[0032] In a step 115.5, preceding or following road vehicles 20 with pantographs 21 contacting the overhead line 10 are taken into account when determining the status data ZD. For this purpose, in a step 107, location coordinates are received from the communication device 49 of the measuring vehicle 30, which were transmitted via the communication device 29 of these road vehicles 20, in order to determine the lifting effect on the contact wires 13 at the measuring position MP based on their distance from the measuring vehicle 30.

[0033] In a step 116, the determined status data ZD are evaluated in an evaluation device 44 of the measuring vehicle 30 with regard to a repair or maintenance requirement for plant objects 11, 12, 13. If a repair or maintenance requirement is identified, a repair or maintenance order RW with the designation and location MP of the affected plant object 11, 12, 13 is automatically triggered in a step 117.

Claims

1. Method (100) for acquiring state data (ZD) of an electrical overhead line system (10) installed along a stretch of road (SS), with which overhead line system a current collector (21) of an electrically or hybrid-electrically driven road vehicle (20) travelling along the stretch of road (SS) can be brought into contact for power transmission purposes, - wherein, by means of a sensor facility (41) of a measurement vehicle (30) traversing the stretch of road (SS), three-dimensional location data (LD) of environment points (UP) representing a vehicle environment (UMP) is acquired (step 102) in each case at measurement points (MP), - wherein, by means of a satellite-based position determination facility (42) of the measurement vehicle (30), spatial coordinates (OK) of the measurement positions (MP) are determined (step 101), - wherein, by assigning the spatial coordinates (OK) of a measurement position (MP) to the location data (LD) acquired at this measurement position (MP), an environment point cloud (UPW) with geocoordinates (GK) of the acquired environment points (UP) is generated (step 108), - wherein, by means of an object recognition facility (43), - one or several fixed reference objects (RO1, RO2, RO3) with known reference coordinates (RK) present in the vehicle environment (UMP) and - one or several system objects (11, 12, 13) of the overhead line system (10) present in the vehicle environment (UMP) are recognised (steps 109, 110) from the geocoordinates (GK) of the environment point cloud (UPW) generated, - wherein a deviation (ΔGR) of the geocoordinates (GK) of the environment points (UP) assigned to a recognised reference object (RO1, RO2, RO3) from the reference coordinates (RK) thereof is ascertained (step 112) and the geocoordinates (GK) of all environment points (UP) of the environment point cloud (UPW) are corrected (step 113) by the deviation (ΔGR) ascertained, and - wherein, by means of the object recognition facility (43), state data (ZD) of the system objects (11, 12, 13) is ascertained (step 115) from the corrected geocoordinates (GK') of the system objects (11, 12, 13).

2. Method (100) according to the preceding claim, - wherein state data (ZD) of a system object (11, 12, 13) is ascertained (step 115.1) from a comparison of the corrected geocoordinates (GK') of the system object (11, 12, 13) with predefined target state data (ZD!) of the system object (11, 12, 13).

3. Method (100) according to one of the preceding claims, - wherein state data (ZD) of a system object (11, 12, 13) is ascertained (step 115.2) from a comparison of the corrected geocoordinates (GK') of the system object (11, 12, 13) with corrected geocoordinates (GK'*) of said system object (11, 12, 13) recorded in an earlier measurement run.

4. Method (100) according to one of the preceding claims, - wherein by means of the object detection facility (43), one or several roadway marking objects (FO1, FO2) of the stretch of road (SS) are recognised (step 111) from the geocoordinates (GK) of the environment point cloud (UPW) generated, - wherein the corrected geocoordinates (GK') of the roadway marking objects (FO1, FO2) are used (step 115.6) as a reference line for the state data (ZD) of the system objects (11, 12, 13).

5. Method (100) according to one of the preceding claims, - wherein masts (11) of the overhead line system (10) and / or signposts (RO1) on the stretch of road (SS) and / or bridges (RO2) spanning the stretch of road (SS) and / or restraint systems (RO3) of the stretch of road (SS) are recognised as reference objects.

6. Method (100) according to one of the preceding claims, - wherein a location and / or a wear and / or a defect and / or a loss of a system object (11, 12, 13) of the overhead line system (10) is ascertained as state data (ZD).

7. Method (100) according to one of the preceding claims, - wherein, by means of one or several sensor units (45, 46, 47) of the measurement vehicle (30), video data (VD) and / or thermal imaging data (TD) and / or electromagnetic field data (FD) of system objects (11, 12, 13) of the overhead line system (10) is acquired (steps 103, 104, 105) in each case at measurement positions (MP), - wherein the acquired video data (V) and / or thermal imaging data (TD) and / or electromagnetic field data (FD) is referenced (step 114) with the spatial coordinates (OK) corrected by the deviation (ΔGR) ascertained, and - wherein the referenced video data (VD) and / or thermal imaging data (TD) and / or electromagnetic field data (FD) is considered (step 115.3) when determining the state data (ZD).

8. Method (100) according to one of the preceding claims, - wherein the weather conditions prevailing at the respective measurement positions (MP) during the measurement run are considered (step 115.4) when ascertaining the state data (ZD).

9. Method (100) according to one of the preceding claims, - wherein road vehicles (20) travelling ahead or behind with current collectors (21) in contact with the overhead line (13) are considered (step 115.5) when ascertaining the state data (ZD) .

10. Method (100) according to one of the preceding claims, - wherein the state data (ZD) ascertained is evaluated (step 116) with respect to a repair or maintenance requirement, and - wherein, if a repair or maintenance requirement is identified, a repair or maintenance order (RW) with the designation and location (MP) of the affected system object (11, 12, 13) is automatically triggered (step 117).