Robust self-localisation using satellite navigation

WO2025185883A8PCT designated stage Publication Date: 2025-10-02SIEMENS MOBILITY GMBH
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Patent Information

Application Number
PCT/EP2025/052217
Authority / Receiving Office
WO · WO
Patent Type
Applications
Current Assignee / Owner
Priority Date
2024-03-04
Filing Date
2025-01-29
Publication Date
2025-10-02

AI Technical Summary

Technical Problem

Existing GNSS systems for rail vehicles are susceptible to local disturbances such as multipath propagation and diffraction effects, and targeted attacks like jamming and spoofing, which compromise the accuracy and reliability of self-localization.

Method used

A method and device for validating self-localization using at least two GNSS receiving devices positioned at a known distance, comparing estimated distances and positions with known values, and applying statistical methods to detect and discard unreliable measurements, while utilizing multiple GNSS receivers and directional properties to enhance accuracy and reliability.

Benefits of technology

Maintains precise and reliable self-localization even in the presence of local interference and attacks, ensuring accurate positioning for automated rail operations.

✦ Generated by Eureka AI based on patent content.

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Abstract

The invention relates to a method for self-localisation using satellite navigation. In the method, at least two GNSS receiving devices (A1, A2), which are positioned at a previously known distance (dv) from one another, are self-localised, wherein a first ego position (P1) of a first GNSS receiving device (A1) is determined on the basis of a satellite navigation signal which is received by the first GNSS receiving device (A1), and a second ego position (P2) of a second GNSS receiving device (A2) is determined on the basis of a satellite navigation signal which is received by the second GNSS receiving device (A2). An estimated distance (ds) between the first GNSS receiving device (A1) and the second GNSS receiving device (A2) is determined on the basis of the first ego position (P1) and the second ego position (P2). The estimated distance (ds) is compared with the previously known distance (dv). Finally, on the basis of a result (EG) of the comparison, it is determined whether the self-localisation of the GNSS receiving devices (A1, A2) is sufficiently precise and reliable. The invention further relates to a validation device (20). Finally, the invention relates to a vehicle (40).
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Description

[0001]202401555 1 Description Robust self-localization with satellite navigation The invention relates to a method for validating self-localization with satellite navigation. The invention further relates to a validation device. The invention also relates to a vehicle with such a validation device. If rail transport is to be more automated, aspects of assisted and driverless train operation are usually also discussed. Precise and robust localization of a rail vehicle in the track network is a crucial requirement for achieving such automation. For this purpose, so-called GNSS systems (GNSS stands for "global navigation satellite system"), such as GPS (GPS stands for "global positioning system"), are used for global localization. However, the accuracy and reliability of a GNSS system are influenced by various interference factors.Improvements to GNSS systems, such as DGPS (DGPS stands for "Differential GPS") or RTK (RTK stands for "Real Time Kinematics," a method known from geodesy for the precise determination of position coordinates using satellite navigation methods), can minimize atmospheric disturbances and inaccuracies in the time measurement of GNSS satellites, thus achieving a positioning accuracy of a few centimeters, at least with a clear line of sight to the satellites. However, local disturbances, such as multipath propagation or diffraction effects of the GNSS signals on or by buildings, are not compensated for by the above-mentioned correction systems. Targeted attacks, such as jamming or spoofing, cannot be detected either.Jamming involves the deliberate interference with 202401555 2 satellite signals so that the satellite signals cannot be received. Spoofing involves simulating satellite signals in order to manipulate or influence position determination based on the satellite signals. The objective is therefore to achieve robust and precise localization of a vehicle, in particular a rail vehicle, even when interference phenomena occur. This objective is achieved by a method for validating self-localization with satellite navigation according to patent claim 1, a validation device according to patent claim 12, and a vehicle according to patent claim 13.In the method according to the invention for validating self-localization using satellite navigation, self-localization is performed by at least two GNSS receiving devices positioned at a known distance from each other. As will be explained in more detail later, the GNSS receiving devices positioned at a known distance are preferably arranged on a vehicle, particularly preferably on a rail vehicle, but they can also be stationary. A GNSS receiving device is understood to be a device with which GNSS signals from satellites can be received and an ego position of the GNSS receiving device can be determined.In the method according to the invention, a first ego position of a first GNSS receiving device of the GNSS receiving devices positioned at a known distance is determined based on a satellite navigation signal, and a second ego position of a second GNSS receiving device positioned at the known distance of the positioned GNSS receiving devices from the first 202401555 3 GNSS receiving device is determined based on a satellite navigation signal. Furthermore, an estimated distance between the first GNSS receiving device and the second GNSS receiving device is determined based on the first ego position and the second ego position. The estimated distance is compared with the known distance. As part of a validation, it is determined based on the comparison result whether the self-localization of the GNSS receiving devices is sufficiently precise and reliable.If the deviation between the previously known distance and the estimated distance is too large, the determined ego positions are discarded, and the measurements are preferably repeated by the GNSS receiving devices. Advantageously, only reliable and correct measurement data are used for self-localization. The validation device according to the invention has an input interface for receiving position data from at least two GNSS receiving devices positioned at a previously known distance from one another, which are configured to perform self-localization.The GNSS receiving devices are configured to determine a first ego position of a first GNSS receiving device of the two receiving devices based on a satellite navigation signal and to determine a second ego position of a second GNSS receiving device of the two receiving devices based on a satellite navigation signal. The validation device is preferably arranged on a vehicle, particularly preferably a rail vehicle. Part of the validation device according to the invention is also a distance determination unit for determining an estimated distance between the first GNSS receiving device and the second GNSS receiving device based on the first ego position received by the 202401555 4 input interface and the second ego position. The validation device according to the invention further comprises a comparison unit for comparing the estimated distance with the previously known distance.In addition, the validation device according to the invention comprises a validation unit for determining, based on the result of the comparison, whether the self-localization of the GNSS receiving devices is sufficiently precise and reliable. During validation, additional uncertainties in the individual measurements and the calibration of the GNSS receiving devices can be taken into account. These uncertainties can be determined using a static and statistical test. Such a test is therefore preferably carried out at rest at a previously known position. In this case, a large number of ego position determinations are carried out and statistical data of these position values ​​are generated. Based on the statistical data, a plausibility level can be defined at which the measurements can still be trusted. Such a plausibility level can have one or more threshold values ​​that are used during validation orthe comparison should not be exceeded if the position data is to be released. The uncertainties of the individual GNSS receiving devices are preferably determined using a statistical method, and plausibility levels are defined on this basis. Such statistical methods preferably include a comparison with a threshold value determined by a χ2 distribution. If two measurements are available which have a known relationship to one another, the measurement points 202401555 5 can be converted into one another using the known transformations characterizing the relationship. This also applies to the measurement uncertainties. These can then be determined using the Mahalanobis distance. The Mahalanobis distance D is given by: The measurement points x and y correspond to the same transformed measurement points, Σ corresponds to the transformed covariance matrix of the two measurements. The χ2 function can be used to determine the volume or the probability with which the measurement points correspond to the joint measurement uncertainty. On this basis, a threshold is determined, e.g., 3 * Σ -> 99.73%, with which the Mahalanobis distance can be compared. The probability indicates how often this threshold selection is correct. Details on the application of the Mahalanobis distance are described on the Wikipedia page "Mahalanobis distance" at https: / / en.wikipedia.org / wiki / Mahalanobis_distance. Further in-depth information on this topic can be found in PC Mahalanobis: On the generalized distance in statistics. In: Proceedings of the National Institute of Science of India. Volume 2, No. 1, 1936, pp. 49-55.To further determine the lower thresholds, variable attenuators can be used in the receiver. "Lower thresholds" here refer to the lowest signal-to-noise ratio at which position determination is still possible. Typical reception strengths of signals from individual satellites can also be determined statistically. Amplitude deviations can be determined in this way by comparing the reception strengths with reference values. Such deviations indicate interference, particularly spoofing. 202401555 6 Advantageously, the accuracy of position determination can be maintained even in the event of local interference, such as multipath propagation or a diffraction effect of the GNSS signals on and through buildings, or the position measurement can be restricted to GNSS receiving devices that are not affected by the local interference.If all receiving devices are affected by the disruption, positioning can still be determined using older, already validated position data. Targeted attacks, such as jamming or spoofing, can also be detected, as these generally lead to implausible position data. The vehicle according to the invention, preferably a rail vehicle, has GNSS receiving devices, a validation device according to the invention for generating validated position data of the vehicle, and a control device for assisted or automated control of a vehicle's journey based on the generated position data of the vehicle. The vehicle according to the invention shares the advantages of the validation device according to the invention.Some of the aforementioned components of the validation device according to the invention can be implemented entirely or partially in the form of software modules in a processor of a corresponding computer system. A largely software-based implementation has the advantage that computer systems already used in vehicle control and monitoring can be easily retrofitted with a software update to operate in the manner according to the invention.In this respect, the object is also achieved by a corresponding computer program product with a computer program that can be loaded directly into a computing system, with program sections to carry out the steps of the method according to the invention for validating self-localization with satellite navigation, in particular the sub-steps for determining an estimated distance between the first GNSS receiving device and the second GNSS receiving device on the basis of the first ego position and the second ego position, for comparing the estimated distance with the previously known distance and for carrying out a validation of the GNSS receiving devices on the basis of a result of the comparison, which provides information as to whether the self-localization of the GNSS receiving devices is sufficiently precise and reliable, when the program is executed in the computing system.Advantageously, such a computer program product can, in addition to the computer program, optionally comprise additional components, such as documentation, and / or additional components, including hardware components, such as hardware keys (dongles, etc.) for using the software. A computer-readable medium, e.g. a memory stick, a hard disk, or another portable or permanently installed data storage device, on which the program sections of the computer program that can be read and executed by a computer system are stored, can be used for transport to the computer system and / or for storage on or in the computer system. The computer system can, for example, have one or more cooperating microprocessors or the like for this purpose. The dependent claims and the following description each contain particularly advantageous embodiments and developments of the invention.In particular, the claims of one claim category can also be developed analogously to the dependent claims of another claim category and their description parts. Furthermore, within the scope of the invention, the various features of different embodiments and claims can also be combined to form new embodiments. 202401555 8 In a preferred embodiment of the inventive method for validating self-localization with satellite navigation, the validation step comprises the following steps if the result of the comparison shows a deviation between the previously known distance and the estimated distance exceeds a predetermined maximum deviation: - the determined ego positions are discarded, - a message is issued that the GNSS receiving devices whose distance was determined are unreliable.Subsequently, after a predetermined time interval, the measurements are repeated by the GNSS receiving devices to determine whether the GNSS receiving devices might be valid at a later time or whether they might still be invalid. Advantageously, only reliable position data is used for geolocating the GNSS receiving devices. Furthermore, the user is alerted that one or more GNSS receiving devices are experiencing interference. Furthermore, the validation is continuously updated so that a dynamic interference phenomenon can be tracked and, thanks to the updates, a maximum number of GNSS receiving devices can be utilized.In a variant of the inventive method for validating self-localization with satellite navigation, more than two GNSS receiving devices are used in the self-localization step, and individual GNSS receiving devices whose GNSS signals are disrupted are identified based on several previously known distances between the GNSS receiving devices. Advantageously, individual GNSS receiving devices can be located and identified based on several distances between different GNSS receiving devices, since the distance of the respective GNSS receiving device to each of the other GNSS receiving devices is also corrupted by a corrupted signal. If the signals from the other GNSS receiving devices are correct, their distances from one another are determined correctly.If more than two GNSS receivers are used for self-localization, an exclusion procedure is preferably used to identify individual GNSS receivers as unreliable based on the result, and only their determined ego positions are discarded. This advantageously allows individual GNSS receivers that are subject to interference to be identified, allowing the maximum possible number of GNSS receivers to be used for self-localization. Alternatively, an inclusion procedure can be used for validation, which determines which GNSS receivers belong to a group of reliable GNSS receivers. Methods such as RANSAC (RANSAC stands for "Random Sample Consensus") or Prediction by Partial Matching are suitable for implementing an inclusion procedure. The application of the RANSAC method is described, for example, in Martin A.Fischler and Robert C. Bolles: Random Sample Consensus: A Paradigm for Model Fitting with Applications to Image Analysis and Automated Cartography. March 1980. Prediction by Partial Matching is a family of adaptive statistical data compression algorithms based on context models and forecasts. Particularly preferred is the use of multiple groups of GNSS receivers with directional properties for self-localization, and the angle of the satellites relative to a respective group of GNSS receivers is measured and compared with the angle of the satellites relative to the respective group of GNSS receivers, which is determined based on a predicted position of the satellites calculated based on ephemeris.202401555 10 Angles of satellite signals can be detected using so-called "digital beamforming" methods, which comprise a signal measurement with a software-defined phase shift. Ephemerides are understood here to be precalculated, time-dependent satellite positions that are stored in a data storage device, in particular in a database. Advantageously, an angle from which a satellite signal is incident on the GNSS receiving device can be verified. If, for example, a deviation is detected, it can be concluded that either a satellite signal is being reflected by objects, in particular walls, or that other interference, in particular spoofing, could be present. Preferably, each of the groups of GNSS receiving devices can be configured such that each direction is covered by at least one GNSS receiving device in each of the groups.If a signal from a specific directional segment is identified as invalid, then in each group of GNSS receivers, only those GNSS receivers or their received signals whose reception range overlaps with the directional segment can be discarded. The inventive method for validating self-localization using satellite navigation can be implemented particularly easily if the known distance between the GNSS receivers is constant. The distance is constant if the GNSS receivers are permanently installed on a base. The base itself can be stationary or mobile. In particular, the base can be formed by a vehicle, preferably a rail vehicle. Advantageously, the known distance can be determined particularly precisely because it does not change.The distance between the GNSS receiving devices can also be non-constant, but temporarily static and can be determined using a suitable model, preferably a vehicle model, particularly preferably a rail vehicle model, preferably as a function of a route, particularly preferably as a function of a rail route. For example, a track layout based on map data can be included in the calculation of the distance. While a rail vehicle, which comprises several carriages, is traveling straight ahead, a static position relationship of GNSS receiving devices, which are arranged on different carriages of the rail vehicle, can be assumed. In this situation, a distance between the GNSS receiving devices can advantageously be determined precisely and as static.If at least two GNSS receiving devices are arranged on a rail vehicle and only one potentially valid GNSS receiving device is temporarily available for self-localization because the other GNSS receiving devices are currently classified as invalid, one of the following estimated variables is preferably used as a comparison variable in the method according to the invention for validating self-localization with satellite navigation: - a speed of the possibly valid GNSS receiving device, - an orientation of the possibly valid GNSS receiving device, - an orientation of a GNSS receiving device or a group of GNSS receiving devices.The estimated value is preferably compared with one of the following pieces of prior information: - a position and / or orientation of a track currently being used, - an elevation profile of the track being used, - a position and / or orientation of a GNSS receiving device during previous measurements. If only one potentially valid GNSS receiving device is available, the distance to one of the other GNSS receiving devices currently classified as unreliable cannot be reliably determined. If the reliability of this one GNSS receiving device is to be tested, data based on satellite signals received by this GNSS receiving device can be compared with reference data, preferably based on map data.Although their accuracy may be lower than the accuracy of the known distance between the GNSS receiving devices, such a substitute comparison may still be reliable enough to detect interference effects that impair the reception of a satellite signal. If only one potentially valid GNSS receiving device is available, one of the following comparison variables is preferably used to verify the satellite data: - Position data based on DRL, - A position of a mobile radio cell in which the potentially valid GNSS receiving device is currently located, - A reference time, - An estimated orientation based on the Earth's magnetic field or on earth movement data. "DRL" is an abbreviation for "Dynamic Radar Localization" and is described in WO 2022 / 228738 A1.Advantageously, these data can be used as comparison data to determine whether a satellite signal received by a GNSS receiving device is reliable when all other GNSS receiving devices have been classified as currently unreliable. The reference time can be recorded as internet time or from a synchronized, long-term stable clock, in particular an atomic clock, and can be used in particular to forecast ephemerides when incorporating angles from which satellite signals are recorded. Preferably, the at least two GNSS receiving devices are designed and aligned such that every possible orientation is covered. Advantageously, satellite signals can be recorded from all directions and checked for validity. The GNSS receiving devices are preferably aligned such that they cover two independent advantageous ranges.When using GNSS receiving devices on a rail vehicle, these areas can cover the area to the left and right of the rail vehicle. In one variant of the inventive method for validating self-localization using satellite navigation, the reliability of the self-localization of the at least two GNSS receiving devices is determined by determining a plurality of ego position measurements from a measurement sequence over time and applying a clustering algorithm, in particular a "prediction by partial matching" or a RANSAC algorithm, to the estimated values ​​of the ego position measurements. The invention is explained in more detail below with reference to the attached figures using exemplary embodiments.1 shows a flowchart illustrating a method for validating self-localization with satellite navigation according to an exemplary embodiment of the invention. FIG. 2 shows a schematic representation illustrating an arrangement for validated self-localization with a validation device according to an exemplary embodiment of the invention. FIG. 3 shows a flowchart illustrating a method for validating self-localization with satellite navigation according to an alternative exemplary embodiment of the invention. FIG. 4 shows a schematic representation of a rail vehicle according to an exemplary embodiment of the invention. FIG. 1 shows a flowchart 100 illustrating a method for validating self-localization with satellite navigation. In step 1.I, a self-localization of two GNSS receiving devices A1, A2 positioned at a known distance from each other is carried out. A first ego position P1 of a first GNSS receiving device A1 is determined based on a satellite navigation signal received by the first GNSS receiving device A1, and a second ego position P2 of a second GNSS receiving device A2 is determined based on a satellite navigation signal received by the second GNSS receiving device A2. The constellation of the two GNSS receiving devices A1, A2 is known in advance, so that in particular a distance d. v between the GNSS receiving devices A1, A2 is known in advance. In step 1.II, an estimated distance d sbetween the first GNSS receiving device A1 and the second GNSS receiving device A2 is determined based on the determined first ego position P1 and the determined second ego position P2. In step 1.III, the estimated distance d s then with the previously known distance d vcompared, whereby a comparison result EG is achieved. 202401555 15 Subsequently, in step 1.IV, on the basis of a result EG of the comparison, it is determined whether the self-localization of the GNSS receiving devices A1, A2 is sufficiently precise and reliable. If the result EG indicates that the self-localization is sufficiently precise, i.e. a deviation does not exceed the threshold value SW, which is marked with "n" in FIG 1, the process proceeds to step 1.V. If it is determined that the self-localization is not sufficiently precise, which is marked with "y" in FIG 1, the process returns to step 1.I and the determined position data P1, P2 are discarded. In step 1.V, the determined position data P1, P2 are released if it was determined in step 1.IV that the self-localization is sufficiently precise.FIG. 2 illustrates an arrangement 2 for validated self-localization with a validation device 20 according to an exemplary embodiment of the invention. The arrangement 2 comprises two sensors arranged at a predetermined distance d from one another. vpositioned GNSS receiving devices A1, A2, a first GNSS receiving device A1 and a second GNSS receiving device A2. The first GNSS receiving device A1 is configured to determine a first ego position P1 of the first GNSS receiving device A1 based on a satellite navigation signal S1, and the second GNSS receiving device A2 is configured to determine a second ego position P2 of the second GNSS receiving device A2 based on a satellite navigation signal S2. The validation device 20 according to an embodiment of the invention comprises an input interface 21, which is configured to receive the position data P1, P2 generated by the GNSS receiving devices A1, A2. 202401555 16 Part of the validation device 20 according to the invention is a distance determination unit 22 for determining an estimated distance d sbetween the first GNSS receiving device A1 and the second GNSS receiving device A2 based on the first ego position P1 and the second ego position P2. The validation device 20 according to the invention also has a comparison unit 23 for comparing the estimated distance d s with the previously known distance d vFurthermore, the validation device 20 according to the invention comprises a validation unit 24. The validation unit 24 is configured to compare the comparison result EG with a threshold value SW (see FIG. 1) in order to determine, based on the comparison result EG, whether the self-localization of the GNSS receiving devices A1, A2 is sufficiently precise and reliable. The validation unit 24 outputs a validation result VE, which is used as a criterion in the evaluation of the measured ego positions to determine whether these data should be discarded or may be reused. FIG. 3 shows a flowchart 300 illustrating a method for validating self-localization with satellite navigation according to an alternative embodiment of the invention. In step 3.I is a self-localization of a plurality of N (N is an integer greater than 2) GNSS receiving device groups AG1, AG2, AG positioned at a previously known distance from each other. N This involves determining a first ego position P1 of a first GNSS receiver group AG1 and an angle W 1s , from which a satellite signal from a satellite is received by the first GNSS receiving device group AG1, is determined based on the satellite navigation signal. Furthermore, a second ego position P2 of a second GNSS receiving device group AG2 202401555 17 and a second angle W 2s , from which a satellite signal from a satellite is received by the second GNSS receiving device group AG2, is determined based on the satellite navigation signal. Analogously, an Nth ego position P N an Nth GNSS receiving facility group AG N and an angle W Ns, from which a satellite signal from a satellite from the Nth GNSS receiving equipment group AG N is received, based on the satellite navigation signal. In step 3.II, an estimated distance d s12 , d s13 , …, d sN-1N between the reception facility groups AG1, AG 2, …, AG N based on the ego positions P1, P2, …, P determined in step 3.I N In step 3.III, in addition to a comparison of the estimated distances d s12 , d s13 , …, d sN-1N with the previously known distances dv 12 , dv 13 , …, dv N-1N of the reception facility groups AG1, AG2, AG N also a comparison of the measured angles W 1s , W 2s , …, W NS the satellites to the receiving equipment groups AG1, AG 2, …, AG N with pre-calculated or predicted angle values ​​W 1v, W 2v , …, W Nv These pre-calculated angle values ​​W 1v , W 2v , …, W Nv are determined based on the satellite ephemeris. In this way, erroneously received satellite signals are identified. In step 3.IV, the individual results EG1, EG2, ..., EG m+N (m = 0.5 N * (N-1)) of the comparison carried out in step 3.III with suitable threshold values ​​SW1, SW2, …, SW m+N compared. In case results EG1, EG2, …, EG m+N , i.e. deviations greater than assigned threshold values ​​SW1, SW2, …, SW m+N are, which is marked with “y” in FIG 3, the assigned determined ego positions P1, P2, …, P N of the relevant reception facility groups AG1, AG 2, …, AG Ndiscarded and, if necessary, a return to step 3.I is made and, after a predetermined time interval, a new validation is carried out. 202401555 18 In the event that, in step 3.IV, results EG1, EG2, …, EG m+N , i.e. deviations less than or equal to assigned threshold values ​​SW1, SW2, …, SW m+N are, which is marked with "n" in FIG 3, the process proceeds to step 3.V and the assigned determined ego positions P1, P2, ..., P N of the relevant reception facility groups AG1, AG 2, …, AG N as validated position data P1, P2, …, P N In addition to a review of the satellite-based distance between individual receiving device groups AG1, AG 2, …, AG N In the embodiment illustrated in FIG 3, a check of measured angles of satellites relative to the individual receiving device groups AG1, AG2, …, AG N . Only position data P1, P2, …, P N to reception facility groups AG1, AG 2, …, AG N , which also include the angles W 1s , W 2s , …, W Ns of the satellites relative to the receiving device groups AG1, AG 2, …, AG Nwere correctly determined are released. FIG. 4 shows a schematic representation of a rail vehicle 40 according to an exemplary embodiment of the invention. The rail vehicle 40 comprises a plurality of GNSS receiving devices A1, A2, which receive satellite navigation signals S1, S2 and forward them to a validation device 20, which is also part of the rail vehicle 40. A validation result VE generated by the validation device 20 is transmitted to a control device 41 included in the rail vehicle 40. The control device 41 is configured to generate control commands based on ego position data from the GNSS receiving devices A1, A2 for controlling the rail vehicle 40.Finally, it is pointed out once again that the methods and devices described above are merely preferred embodiments of the invention and that the invention can be varied by a person skilled in the art without departing from the scope of the invention, insofar as it is defined by the claims. For the sake of completeness, it is also pointed out that the use of the indefinite articles “a” or “an” does not exclude the possibility that the features in question may be present in multiple copies. Likewise, the term “unit” does not exclude the possibility that it consists of several components, which may also be spatially distributed. Regardless of the grammatical gender of a particular term, persons with male, female or other gender identity are included.

Claims

202401555 20 claims 1. Method for validating a self-localization with satellite navigation, comprising the steps of: - carrying out a self-localization of at least two objects located at a previously known distance (d v ) positioned GNSS receiving devices (A1, A2), wherein a first ego position (P1) of a first GNSS receiving device (A1) is determined on the basis of a satellite navigation signal (S1) received by the first GNSS receiving device (A1), and a second ego position (P2) of a second GNSS receiving device (A2) is determined on the basis of a satellite navigation signal (S2) received by the second GNSS receiving device (A2), - determining an estimated distance (d s) between the first GNSS receiving device (A1) and the second GNSS receiving device (A2) based on the first ego position (P1) and the second ego position (P2), - comparing the estimated distance (d s ) with the previously known distance (d v ) as a comparison value, - performing a validation of the GNSS receiving devices (A1, A2), wherein, based on a result (EG) of the comparison, it is determined whether the self-localization of the GNSS receiving devices (A1, A2) is sufficiently precise and reliable.

2. Method according to claim 1, wherein - the step of validation is carried out in the event that the result (EG) indicates a deviation between the previously known distance (d v ) and the estimated distance (d s) which exceeds a predetermined maximum deviation, comprising the steps of: - discarding the determined ego positions (P1, P2), - issuing a message that the GNSS receiving devices (A1, A2) are not reliable, - repeating the measurements by the GNSS receiving devices (A1, A2) after a predetermined time interval 202401555 21 is carried out to determine whether the GNSS receiving devices (A1, A2) may be valid at a later time.

3. Method according to one of the preceding claims, wherein - in the step of self-locating, more than two GNSS receiving devices (A1, A2, ..., A N ) are used and - in the step of determining the distance, several distances (ds 12 , ds 13 , …, ds N-1N ) between the GNSS receiving devices (A1, A2, …, A N ) and - in the validation step based on previously known distances (dv12 , dv 13 , …, dv N-1N ) of the GNSS receiving devices (A1, A2, …, A N ) and the distances determined during self-localization (ds 12 , ds 13 , …, ds N-1N ) individual GNSS receiving devices whose GNSS signal is disturbed are identified using an exclusion process.

4. The method according to claim 3, wherein in the validation step, individual GNSS receiving devices (A1, A2) are determined to be unreliable on the basis of the result (EG) using an exclusion process, and only their determined ego positions (P1, P2) are discarded.

5. The method according to one of the preceding claims, wherein a plurality of groups (AG1, AG 2, …, AG N ) of GNSS receivers with directional properties for self-localization and an angle (W 1s , W 2s, …, W Ns) of satellites from which a satellite navigation signal is received, relative to a respective group of GNSS receiving devices (AG1, AG2, …, AG N ) and with an angle (W 1v , W 2v , …, W Nv ) of satellites from which a satellite navigation signal is received, relative to the respective group (AG1, AG2, …, AG N ) of GNSS receiving devices (AG1, AG2, …, AG N ), which was determined on the basis of a predicted position of the satellites, which was calculated on the basis of ephemerides. 202401555 22 6. Method according to one of the preceding claims, wherein the previously known distance (d v) between the GNSS receiving devices (A1, A2) is constant.

7. Method according to one of the preceding claims, wherein the at least two GNSS receiving devices (A1, A2) are arranged on a vehicle.

8. Method according to one of the preceding claims, wherein the at least two GNSS receiving devices (A1, A2) are arranged on a rail vehicle and, in the event that only one potentially valid GNSS receiving device (A1) is available, one of the following estimated variables is used as a comparison variable to validate the one GNSS receiving device (A1): - an ego position (P1) of the GNSS receiving device, - a speed of a GNSS receiving device (A1, A2), - an orientation of a GNSS receiving device (A1, A2) or a group (AG1, AG2) of GNSS receiving devices,- and the estimated value is compared with one of the following prior information: - a position and / or orientation of a currently traveled track, - an elevation profile of the track being traveled, - a position and / or orientation of a GNSS receiving device (A1) and / or a group (AG1, AG2) of GNSS receiving devices during previous measurements.

9. Method according to one of the preceding claims, wherein, in the event that only one potentially valid GNSS receiving device (A1) is available, one of the following values ​​is used as a comparison value: - a position determined by dynamic radar localization, 202401555 23 - a position of a mobile radio cell in which the possibly valid GNSS receiving device (A1) is currently located, - a reference time, - an estimated orientation based on the earth's magnetic field or on the earth's movement.

10. The method according to one of the preceding claims, wherein the at least two GNSS receiving devices (A1, A2) are designed and aligned such that every possible alignment is covered.

11. The method according to one of the preceding claims, wherein the validation of the self-localization of the at least two GNSS receiving devices (A1, A2) is based on determining a plurality of ego position measurements in a measurement sequence over time and applying a clustering algorithm or a RANSAC algorithm to the estimated values ​​of the ego position measurements. 12.Validation device (20), comprising: - a receiving interface (21) for receiving position data (P1, P2) from at least two objects located at a previously known distance (i.e. v ) positioned GNSS receiving devices (A1, A2) for carrying out a self-localization, comprising a first ego position (P1) of a first GNSS receiving device (A1) of the at least two GNSS receiving devices (A1, A2), which was determined on the basis of a satellite navigation signal (S1), and a second ego position (P2) of a second GNSS receiving device (A2) of the at least two GNSS receiving devices (A1, A2), which was determined on the basis of a satellite navigation signal (S2), - a distance determination unit (22) for determining an estimated distance (d s ) between the first GNSS receiving device (A1) and the second GNSS receiving device (A2) based on the first ego position (P1) and the second ego position (P2), 202401555 24 - a comparison unit (23) for comparing the estimated distance (d s ) with the previously known distance (d v), - a validation unit (24) for determining, based on a result (EG) of the comparison, whether the self-localization of the GNSS receiving devices (A1, A2) is sufficiently precise and reliable.

13. A vehicle (40), preferably a rail vehicle, comprising: - a validation device (20) according to claim 12 for validating position data (P1, P2) of the vehicle (40), - a control device (41) for assisted or automated control of a journey of the vehicle (40) based on the generated position data (P1, P2) of the vehicle (40).

14. A computer program product comprising a computer program that can be loaded directly into a memory unit of a computing system, with program sections for executing a method according to one of claims 1 to 11 when the computer program is executed in the computing system.Computer-readable medium on which program sections executable by a computer unit are stored in order to carry out a method according to one of claims 1 to 11 when the program sections are executed by the computer unit.