Validation of a sensor unit of a rail vehicle for object localization

Abstract

An arrangement (1) for validating the function of a sensor unit (7) of a rail vehicle (6) for object localization is described. The arrangement (1) comprises a test track (2) and a test object (3) on the test track (2). The test object (3) comprises a first self-localization unit (4) for determining a reference position (RPT) of the test object (3). The rail vehicle (6) comprises a sensor unit (7) for detecting a relative position (RLP) of the test object (3) to the sensor unit (7), a second self-localization unit (9) for determining an ego position (EP) of the rail vehicle (6), and a position determination unit (8) for determining an absolute position (AP) of the test object (3) based on the detected relative position (RLP) of the test object (3) to the sensor unit (7) and the determined ego position (EP) of the rail vehicle (6).Part of the arrangement (1) is also a validation unit (10) for determining a deviation (AW) of the determined absolute position (AP) of the test object (3) from the reference position (RPT) of the test object (3). A method for validating a function of a sensor unit (7) of a rail vehicle (6) for object localization is also described.

Description

[0001] The invention relates to an arrangement for validating a function of a sensor unit of a rail vehicle for object localization. The invention also relates to a method for validating a function of a sensor unit of a rail vehicle for object localization, as well as a corresponding computer program and a corresponding computer-readable storage medium.

[0002] In rail transport, it occasionally happens that objects, such as people or road vehicles, shopping carts thrown onto the tracks, or even boulders or fallen trees, end up on the track and therefore pose a danger to rail safety. In the case of people and road vehicles, they are also themselves highly endangered due to the possibility of a collision with a moving train. Therefore, such objects must be detected in time to initiate braking for an approaching train, thus preventing a collision between the train and the object. Furthermore, trains on the same track must also be detected to avoid collisions between them. Consequently, one of the critical tasks of a train driver is to scan the track area for potential obstacles.To constantly monitor objects that could collide with the rail vehicle and to decide whether a reaction, such as a braking maneuver, needs to be initiated or not.

[0003] When controlling vehicles without drivers, it is particularly important to have a system that can automatically and correctly locate possible obstacles and decide whether they pose a danger to the vehicle itself or other road users, since by definition monitoring of the track by a driver must be dispensed with.

[0004] For such tasks, lidar systems and radar systems are suitable, as they can detect distances and directions in which objects are located.

[0005] Automated obstacle detection systems have already been experimentally investigated and developed. Infrastructure-based solutions, in which multiple sensors are deployed to monitor a specific section of a railway line, are sometimes used to monitor accident hotspots, such as level crossings. However, it is not feasible to equip the entire rail network with infrastructure-based obstacle detection systems. Therefore, there is a need for an onboard system to fulfill the driver's role of observing and monitoring the railway line.

[0006] Most onboard systems include systems for measuring the position of detected obstacles. Knowing the exact position of a potential obstacle allows for an assessment of the hazards it poses. In particular, the position of the potential obstacle must be determined with sufficient accuracy to estimate its distance from a rail vehicle and whether it is within the vehicle's clearance gauge, or whether it might be within it at a later time.

[0007] To meet safety requirements, the precision of the onboard systems' ability to locate potential obstacles must be tested and validated. Currently, the process for such validation begins with positioning a test object on a test track. Position markers are then defined and arranged on the track. During validation, a rail vehicle equipped with a sensor device being validated approaches the positions marked by these markers. The placement of the position markers is typically done manually, making it quite time-consuming. Furthermore, inaccuracies can occur when the rail vehicle approaches each marker, negatively impacting the reliability of the validation.

[0008] Document DE 10 2019 206 503 A1 describes a method for calibrating a sensor for the environment detection of a vehicle, in which a test object is used next to the test track with a previously determined reference position of the test object.

[0009] The task is therefore to provide an arrangement and a procedure for validating the function of on-board sensors for obstacle localization in rail vehicles, which function more reliably, robustly and accurately than previous solutions.

[0010] This problem is solved by an arrangement for validating a function of a sensor unit of a rail vehicle for object localization according to claim 1 and a method for validating a function of a sensor unit of a rail vehicle for object localization according to claim 13.

[0011] The arrangement according to the invention for validating the function of a sensor unit of a rail vehicle for object localization comprises a test track. As will be explained in detail later, the test track preferably has a shape such that the distance of an object to a center line of the test track can be easily determined. It should be emphasized at this point that the sensor unit preferably comprises a plurality of sensors in order to perform object localization. Typical localization methods include triangulation and / or time-of-flight measurement. As mentioned at least in part at the outset, sensor units for such tasks preferably comprise lidar systems and / or radar systems and / or 3D cameras based on optical or infrared technology.

[0012] The arrangement according to the invention also includes a test object located on the test track. The test object comprises an object to be detected or localized on the test track for testing purposes. Such an object to be localized preferably comprises the silhouette of an object typically found in the field of rail transport, such as the silhouette of a person or a vehicle, which is to be detected and localized in front of the sensor unit of the rail vehicle during validation. Advantageously, such a shape of the test object corresponds to a typical external shape of a potential obstacle encountered in the application, so that the test conditions closely approximate real-world conditions.

[0013] Part of the test object is a first self-localization unit for determining a reference position of the test object. This first self-localization unit determines its own position, which essentially corresponds to the ego position of the test object. The ego position of the test object is used as its reference position. The ego position of the first self-localization unit can be converted into the reference position of the test object if it does not exactly match the ego position or reference position of the test object. The ego position is determined based on the acquisition of measurement data by the first self-localization unit, which is correlated with its own ego position.The measurement data may include time difference measurement data, in particular satellite navigation measurement data, odometric measurement data, distance measurement data, speed measurement data or acceleration measurement data.

[0014] The rail vehicle includes a sensor unit for detecting the relative position of the test object to the sensor unit. For this purpose, the sensor unit measures the direction and distance of the test object relative to the sensor unit. The relative position indicates the position of the test object in a coordinate system that moves along with the rail vehicle or its sensor unit. The rail vehicle also includes a second self-localization unit for determining its own position. More precisely, the second self-localization unit first determines its own position by measuring its own position. .The second self-localization unit determines the ego position of the rail vehicle and the ego position of the rail vehicle's sensor unit. These positions differ minimally but can be easily converted into one another if the rail vehicle's orientation is known. The second self-localization unit determines the rail vehicle's ego position based on measurement data correlated with the rail vehicle's position. Preferably, the second self-localization unit is configured to determine an ego pose of the rail vehicle. Such an ego pose includes not only the rail vehicle's ego position but also its orientation.Advantageously, the ego-pose allows not only the determination of the distance between the rail vehicle and the test object, but also the direction in which the test object is located relative to the rail vehicle's pose, thus enabling the determination of the test object's exact relative position to the rail vehicle. The rail vehicle's orientation, and consequently the orientation of the sensor unit in space, can be determined either by directly measuring the orientation or by deriving it based on the determined ego-position of the rail vehicle and the track alignment of the test section at the ego-position, particularly using map data or satellite navigation data. If the track alignment is known, the rail vehicle's orientation is generally derived from its ego-position. Especially with a straight track alignment, the rail vehicle's orientation is independent of its position.The advantage of this variant is that the orientation of the rail vehicle is fixed and no locally variable orientation of the rail vehicle needs to be taken into account during validation, for example by using map material or by measuring the orientation of the rail vehicle and / or its sensor unit.

[0015] It should also be mentioned that the arrangement according to the invention can advantageously be supplemented by an adjustment unit which, based on the validation, adjusts the position determination of the test object in order to improve or ensure the required accuracy of object localization by the sensors of a railway vehicle in question.

[0016] The rail vehicle of the arrangement according to the invention also includes a position determination unit for determining an absolute position of the test object based on the detected relative position of the test object to the sensor unit and the determined ego position of the rail vehicle. Based on knowledge of the track layout and the ego position of the rail vehicle on the test track, the position determination unit calculates a pose of the rail vehicle. Using the knowledge of the pose of the rail vehicle and the relative position of the test object, the position determination unit calculates an absolute position in a stationary coordinate system, the position and orientation of which are independent of the pose and the current position of the rail vehicle.

[0017] The arrangement according to the invention also includes a validation unit for determining any deviation of the determined absolute position of the test object from the test object's reference position. To determine the deviation, the validation unit compares the determined absolute position of the test object with the test object's reference position. The validation achieves a positive result if the deviation falls below a threshold value. Advantageously, the validation can be automated. In particular, there is no need to manually place markers for individual ego positions of the rail vehicle on the test track.By determining multiple ego positions of the rail vehicle, a geographic map of these ego positions can be created, as will be explained in detail later. During a test run, the rail vehicle then approaches each of these ego positions, determined by its second self-localization unit. Advantageously, the validation can be based on precise geodata for determining the ego position of a rail vehicle in any type of environment without the need for external services or prior determination of stationary infrastructure points. Based on this geodata, all characteristics required for validating an obstacle detection system in the railway environment can be derived, in particular, determining the precision of measuring the distance between an object and the rail vehicle or track.

[0018] In the procedure for validating the function of a sensor unit of a rail vehicle for object localization, a reference position of a test object is determined by a first self-localization unit arranged on the test object. The reference position can be determined, for example, by determining the geographical coordinates of the test object or a specific point on the test object, such as its geometric center.

[0019] Furthermore, the relative position of the test object to a sensor unit mounted on the rail vehicle is determined. This relative position results from the distance and direction measured by the sensor unit in which the test object is located relative to the rail vehicle or the sensor unit.

[0020] Furthermore, an ego position, or preferably the ego pose, of the rail vehicle is determined by a second self-localization unit mounted on the rail vehicle. As already mentioned, the ego pose specifies not only the exact ego position but also the orientation of the rail vehicle. The ego position is preferably given in geographic coordinates. The orientation of the rail vehicle can be described, for example, by an angle relative to a reference direction.

[0021] Based on the detected relative position of the test object to the sensor unit and the determined ego position of the rail vehicle, an absolute position of the test object is determined within the framework of the inventive method.

[0022] Finally, the object localization function of the sensor unit is validated by determining the deviation of the determined absolute position of the test object from the reference position. That is, it is determined whether the deviation in determining the absolute position of the test object falls below a predetermined threshold. The method according to the invention shares the advantages of the arrangement according to the invention.

[0023] The validation method according to the invention can be used in particular for an adjustment procedure in which, based on the validation, an adjustment of the position determination of the test object is carried out in order to improve or ensure the required accuracy of object localization by the sensors of a rail vehicle in question. In such a procedure, based on the deviation measured during the validation, a correction of the orientation of the sensor units and / or a computational correction is carried out to compensate for the determined deviation.

[0024] A large proportion of the aforementioned components of the arrangement according to the invention can be implemented wholly or partially as software modules in a processor of a corresponding computing system, e.g., in a control unit or computing system of the rail vehicle, a computing system of the test object, or even an externally arranged computing system. This applies in particular to the position determination unit of the rail vehicle and the validation unit. A largely software-based implementation has the advantage that even previously used computing systems can be easily retrofitted by means of a software update to operate in the manner of the invention.The problem is therefore also solved by a corresponding computer program product according to claim 14, comprising a computer program that can be directly loaded into a computing system, with program sections to execute the steps of the method according to the invention, at least the steps executable by a computer, in particular the steps of determining an absolute position of the test object and validating the object localization or object localization function, when the program is executed in the computing system. In addition to the computer program, such a computer program product may optionally include additional components such as documentation and / or additional hardware components, such as hardware keys (dongles, etc.) for using the software.

[0025] Furthermore, the problem is solved by a computer-readable storage medium according to claim 15, which serves for transport to the computer system or control unit and / or for storage on or in the computer system or control unit. The computer-readable storage medium can be, for example, a memory stick, a hard drive, or another portable or permanently installed data carrier on which the program sections of the computer program that can be read and executed by a computer system are stored. The computer system can, for example, comprise one or more cooperating microprocessors or the like.

[0026] The dependent claims and the subsequent description each contain particularly advantageous embodiments and further developments of the invention. In particular, the claims of one claim category may also be further developed analogously to the dependent claims of another claim category and their descriptive parts. Furthermore, within the scope of the invention, the various features of different embodiments and claims may also be combined to form new embodiments.

[0027] In one embodiment of the arrangement according to the invention, the test object has a transmitting unit. The transmitting unit is preferably designed to transmit the determined reference position of the test object to the rail vehicle or another device configured for evaluation and validation. Such a transmitting unit enables the transmission of information about the reference position of the test object to a device located remotely from the test object and also the processing of this information at a remote location. For this purpose, a receiving unit is arranged at this remote location, which serves to receive the determined reference position of the test object. Such a remote location can, for example, include the position of the rail vehicle. That is, the rail vehicle can contain the receiving unit.This variant is particularly advantageous when the validation unit is also integrated into the rail vehicle. In this variant, the validation unit receives information about the test object's reference position via the receiver unit and compares it with the test object's absolute position determined by the rail vehicle's position detection unit. However, the validation unit can also be located separately from the rail vehicle, for example, in a stationary position or on a mobile testing device. In this variant, the rail vehicle also includes a transmitter unit to transmit the determined absolute position of the test object to the mobile testing device. Validation in this variant takes place separately from the rail vehicle.

[0028] This variant advantageously requires only a single validation unit for a multiple of rail vehicles, thus saving resources.

[0029] In one embodiment of the arrangement according to the invention, the test object comprises the validation unit and a receiver unit for receiving the absolute position of the test object determined by the position determination unit. Furthermore, the rail vehicle comprises a transmitter unit for transmitting the absolute position of the test object, determined by the position determination unit, to the receiver unit of the test object or the validation unit of the test object. In this embodiment, the evaluation of the test data takes place within the test object itself. The rail vehicle serves merely as a mobile sensor unit for measuring the ego position of the rail vehicle and for measuring the relative position of the test object to the rail vehicle. In this embodiment, the validation of the sensor function of different rail vehicles can be performed with a single validation unit if the same test object is used for validating the sensor function of different rail vehicles.

[0030] In one embodiment of the arrangement according to the invention, the arrangement comprises an evaluation unit separate from the rail vehicle and the test object. In this embodiment, the separate evaluation unit includes the validation unit and a receiver unit for receiving the absolute position of the test object determined by the rail vehicle's position detection unit and for receiving the test object's reference position from the test object. In this embodiment, the rail vehicle includes a transmitter unit for transmitting the absolute position of the test object, determined by the position detection unit, to the separate evaluation unit. This embodiment has the advantage that the evaluation unit can now be used flexibly for validating the function of different rail vehicles and different test objects, requiring only a single validation unit for the aforementioned applications.This approach allows for resource savings. The evaluation unit can be permanently installed at a specific test track, or it can be designed as a mobile or transportable unit for validation on different test tracks. For transport, the evaluation unit can be equipped with a chassis and traction unit for moving between different test tracks. In this latter configuration, the evaluation unit's application range is extended to various test track sections, further increasing resource efficiency through the versatile deployment of the same validation unit.

[0031] The second self-localization unit in or on the rail vehicle of the arrangement according to the invention acquires measurement data for position estimation and orientation estimation for the position and, optionally, the pose of the rail vehicle. This measurement data can be acquired by technically very different types of measuring devices. The aforementioned measurement data can include the following types of measurement data: Satellite navigation data, IMU data (IMU = inertial measurement unit), speed sensor data, odometry data, so-called RTK correction data.

[0032] RTK correction data (RTK = Real-time Kinematics) is used in geodesy for the precise determination of position coordinates using satellite navigation methods. Accuracies of 1 to 2 cm are achieved. The position coordinates are calculated in real time after initialization. The positions are determined using a reference antenna on a reference station and a second antenna mounted on a rover. The rover's position is determined by three-dimensional polar alignment to the reference station using the baseline method. The rover preferably incorporates the second antenna; that is, the rover's second self-locating unit preferably incorporates this second antenna. The reference station can, for example, be part of the test object, and in this case, the first self-locating unit can incorporate the reference antenna.The reference station can also be supplied by another or external facility. The RTK correction data can be provided, in particular, via the mobile network or radio by a facility that generates correction data for satellite navigation.

[0033] An inertial measurement unit measures acceleration and deceleration data and can be used to determine the orientation of a rail vehicle and thus to determine the pose of the rail vehicle.

[0034] Speed ​​sensor data and odometry data can be used to determine the ego position of a rail vehicle.

[0035] In one variant of the arrangement according to the invention, the first and / or the second self-localization unit comprises at least one of the following types of self-localization units: a navigation unit for receiving a satellite navigation signal, a receiving unit for receiving RTK correction data, an inertial measurement unit.

[0036] Satellite navigation can achieve high accuracy for position or direction determination within the framework of differential satellite navigation by supplementing it with reference stations and evaluating the phase shift of the carrier wave. An inertial measurement unit can be used for orientation measurement. Velocity and odometry data can also be used for position determination. Combining different measurement methods is also advantageous. Depending on the situation and the current applicability of the various methods, the measured values ​​from different measurement techniques can be combined, for example, through data fusion, particularly through weighted averaging of the measured values.

[0037] Preferably, the position determination unit of the arrangement according to the invention is configured to determine a position and a path of a center line of the test track based on the ego position of the rail vehicle. If the lateral position of the second self-localization unit on the rail vehicle is known, an absolute position on a center line of the test track can be determined by traversing the test track. Advantageously, this center line can be used as a reference line for measuring the lateral position of the test object.

[0038] Preferably, the position detection unit is configured to determine the distance of the test object from the center line. The distance of a point to the center line can be determined using linear algebra. This involves finding the vector that passes through the point and is perpendicular to the center line. Advantageously, knowing the distance of a point, and in particular an object, from the center line allows one to determine whether the object is located within the operating area of ​​the rail vehicle or on the track itself.

[0039] Preferably, the validation unit of the arrangement according to the invention is configured to determine a deviation of the vehicle-side measured distance of the test object from the center line from a reference distance of the test object to the center line. The reference distance of the test object to the center line can be calculated, for example, based on the reference position of the test object and knowledge of the course of the center line. The comparison yields a lateral deviation of the vehicle-side measured absolute position of the test object.

[0040] Preferably, the position detection unit is configured to determine the distance between the rail vehicle and the test object, preferably in the longitudinal direction. Distance measurement can be performed, for example, trigonometrically or as a time-of-flight measurement.

[0041] Preferably, the position determination unit is configured to determine a deviation between the distance detected on the vehicle side, preferably in the longitudinal direction, between the rail vehicle and the test object, and a reference distance between the rail vehicle and the test object, preferably in the longitudinal direction, determined on the basis of the reference position of the test object and the determined ego position of the rail vehicle.

[0042] Preferably, the test track has a straight course. Advantageously, with this geometric shape of the test track, the pose of the rail vehicle does not change depending on its position on the track. Therefore, the pose of the rail vehicle does not need to be determined in order to ascertain the relative or absolute position of the test object based on sensor data.

[0043] Preferably, the test track follows a curved path, and a center line of the test track is approximated by straight segments. Advantageously, the distance of a point on an object to these segments can be calculated using simple linear algebraic methods.

[0044] The invention is explained in more detail below with reference to the accompanying figures and exemplary embodiments. The figures show: FIG 1 a schematic representation of an arrangement for validating a function of a sensor unit of a rail vehicle for object localization according to an embodiment of the invention, FIG 2 a flowchart illustrating a method for validating a function of a sensor unit of a rail vehicle for object localization according to an embodiment of the invention, FIG 3 a schematic representation of a process for ErProvision of a map with ego positions, which the rail vehicle will visit during validation, FIG 4 a presentation of the possible errors in determining the ego position of a rail vehicle and their effects on object localization, FIG 5 a representation of the positions of objects with different lateral distances to a center line of a railway track, FIG 6 a diagram illustrating the determination of the minimum distance between a point and a constructed line segment, FIG 7 a diagram illustrating the determination of a longitudinal distance between a point and an auxiliary point in the longitudinal direction, FIG 8 a circular distance on a sphere, FIG 9 a representation of angular relationships in a circular arc, FIG 10 a diagram that documents a validation process, FIG 11 a schematic representation of an arrangement for validating a function of a sensor unit of a rail vehicle for object localization according to a second embodiment of the invention, FIG 12 a schematic representation of an arrangement for validating a function of a sensor unit of a rail vehicle for object localization according to a third embodiment of the invention.

[0045] In FIG 1 Figure 1 shows a schematic representation of an arrangement 1 for validating a function of a sensor unit 7 of a rail vehicle 6 for object localization. The arrangement 1 comprises a straight test track 2 on which a test object 3, which is in FIG 1 The right-hand side is only schematically depicted. Furthermore, a rail vehicle 6 is located on test track 2, which is in FIG 1 drawn on the left side.

[0046] The test object 3 is arranged at a distance dr from the center line 2a of the test track 2. The test object 3 comprises a first self-localization unit 4, in this embodiment a satellite navigation unit, for determining a reference position RP T of the test object 3. . For this purpose, the first self-localization unit 4 receives a satellite signal, on the basis of which it determines the reference position RP T of the test object 3. The test object 3 also includes a transmitter unit 5 for transmitting the determined reference position RP T of the test object 3 to the rail vehicle 6 via radio.

[0047] The rail vehicle 6 includes the aforementioned sensor unit 7, in this embodiment a lidar unit, for detection and localization, i.e. .To determine the relative position RLP of the test object 3 to the sensor unit 7, the sensor unit 7 measures the longitudinal distance dl of the test object 3 to the sensor unit 7 and the lateral distance dr of the test object 3 to the center line 2a of the test track 2. The position and course of the center line 2a can be determined in advance by traversing the test track 2 and recording the ego position EP of the rail vehicle 6 at different points along the test track 2. To determine the ego position EP, the rail vehicle 6 includes a second self-localization unit 9.

[0048] The second self-localization unit 9 comprises in the FIG 1 The illustrated embodiment also includes a satellite navigation unit for receiving a satellite signal to determine the ego position EP of the rail vehicle 6. Furthermore, the rail vehicle 6 also comprises a position determination unit 8, which determines an absolute position AP of the test object 3 based on the detected relative position RLP of the test object 3 to the sensor unit 7 and based on the determined ego position EP of the rail vehicle 6. The absolute position AP determined by the position determination unit 8 is also transmitted to a validation unit 10, which is also part of the rail vehicle 6. The validation unit 10 performs a comparison between the determined absolute position AP of the test object 3 and the reference position RP T of the test object 3 determined by the test object 3 itself.For this purpose, the rail vehicle 6 includes a receiver unit 11, with which the information about the reference position RP T is received by radio from the test object 3.

[0049] In FIG 2 A flowchart 200 is shown, which illustrates a method for validating a function of a sensor unit 7 of a rail vehicle 6 for object localization according to an embodiment of the invention.

[0050] In step 2.I, a reference position RP T of a test object 3 is determined by a first self-localization unit 4 arranged in the test object 3. For this purpose, a satellite signal PS is received by the first self-localization unit 4, in this embodiment a satellite navigation unit.

[0051] In step 2.II, the determined reference position RP T of the test object 3 is transmitted to a receiving unit 11 of the rail vehicle 6 by a transmitting unit 5 arranged on the test object 3.

[0052] In step 2.III, the relative position RLP of the test object 3 to a sensor unit 7 arranged on the rail vehicle 6 is detected. For this purpose, the sensor unit 7 measures the position in which it is located. FIG 2 The illustrated embodiment includes a lidar unit, a distance and an azimuth of the test object 3 relative to the orientation of the sensor unit 7.

[0053] In step 2.IV, an additional ego position EP of the rail vehicle 6 is determined by a second self-localization unit 9 arranged on the rail vehicle 6. The orientation of the rail vehicle 6 is also known based on the known geometry of the test track 2; for example, the test track 2 is straight.

[0054] In step 2.V, an absolute position AP of the test object 3 is determined based on the detected relative position RLP of the test object 3 to the sensor unit 7 and the determined ego position EP as well as the known orientation of the rail vehicle 6.

[0055] In step 2.VI, the object localization function of the sensor unit 7 is validated by determining a deviation AW of the determined absolute position AP of the test object 3 from the reference position RP T of the test object 3.

[0056] FIG 3 shows a schematic representation of a process for creating a map with Ego positions EP1, ..., EP8, which the rail vehicle 6 (see FIG 1 ) during validation. The ego positions EP1, EP2 ..., EP8 are located at different positions on test track 2. Therefore, the distances dl (see FIG 1 The measurements between test object 3 and rail vehicle 6 at the different ego positions EP1, ..., EP8 also differ. Based on the measurement data at different measurement positions, measurement accuracies can be determined as a function of distances or intervals dl, and it can be established up to which distance the sensor unit 7 meets the minimum requirements for measurement accuracy.

[0057] In FIG 4 This illustrates the potential errors in determining the ego position EP of a rail vehicle 6 and their effects on object localization. An inaccurate determination or deviation δL of the ego position EP of the rail vehicle 6 in the longitudinal L and a deviation δLat in the lateral Lat can lead to false positive or false negative results, respectively. FIG 4 An example is shown where an object O is actually located on a railway track, but due to a deviation in the determination of the ego position EP of the rail vehicle 6, it is incorrectly located outside the track area. This displacement results from the deviation δL of the measured ego position EP of the rail vehicle 6 from its true ego position. The correct classification of the detected object O depends not only on the correct determination of the ego position EP of the rail vehicle 6, but also on the correct determination of the relative position RLP of object O from the rail vehicle 6. Both deviations are ultimately included in the validation, since both the ego position EP of the rail vehicle 6 and the relative position RLP correspond to the true position of object O. In the case of validation with test object 3, this is the reference position RP T of test object 3 (see [reference]). FIG 1 ), influencing the absolute position AP of object O to be compared.

[0058] FIG 5 Figure 1 shows a representation of the positions of objects O with different lateral distances to a center line 2a of a railway track 6. The center line 2a is composed of straight track segments STA that approximate the true track profile, which is characterized by curves.

[0059] In FIG 6 This diagram illustrates the determination of the minimum distance between a point P with coordinates (x₀, y₀) and a constructed line segment STA with points Q and Q' with coordinates (x₁, y₁) and (x₂, y₂). The distance d between point P and the line segment defined by the line is given by... y = − a b x − c b The line segment shown, containing points Q and Q', is represented by the vector r. The smallest distance dr between point P and the line is given by... y = − a b x − c b r is a constructed line segment that runs at a right angle to the line y and is represented by the vector v. For r to be orthogonal to the line y, the dot product of the vector r and the vector running in the direction of the line y must sum to zero.

[0060] The vector v , which is perpendicular to the line y, is then calculated as v → = a b

[0061] The smallest distance dr is obtained as the projection of the vector r on the vector v The distance dr between point P and the line y = − a b x − c b A brief calculation thus yields: d r = x 2 − x 1 y 1 − y 0 − x 1 − x 0 y 2 − y 1 x 2 − x 1 2 + y 2 − y 1 2

[0062] In FIG 7 The diagram illustrates the determination of a longitudinal distance dl between a point P0 with coordinates (x0, y0) and an auxiliary point P' with coordinates (xr', yr') along the constructed line STA in the longitudinal direction. Using the lateral distance dr calculated perpendicular to the line y between point P with coordinates (xr, yr) and the line y, the hypotenuse d0 spanning the line is first calculated to determine the longitudinal distance dl. The longitudinal distance dl is then obtained as the leg of the triangle formed by the other two known distances dr and d0.

[0063] In FIG 8 The figure shows the distance between two points on a sphere, specifically between points P and P0. The Haversine formula can be used to calculate the distance between any two given points on a sphere. Therefore, the distance between two points whose geocoordinates are known can be easily calculated.

[0064] In FIG 9 A representation of angular relationships in a unit circle is shown. Points A, B, and the center O' form an isosceles triangle whose legs have a length of 1. One of the legs, the altitude h of the isosceles triangle, and half the base of the isosceles triangle form a right triangle with the leg of unit length 1 as the hypotenuse and the angle θ between the leg of the isosceles triangle and the altitude h. The base of the isosceles triangle is divided into two equal halves at the foot C. If the altitude h is extended in the x-direction, the extended ray intersects the unit circle at point D. The function value sin θ is given by half the base of the isosceles triangle. The function value cos θ is given by the altitude h of the isosceles triangle, and the function value hav θ (hav = abbreviation for "haversine") is given by the segment between points C and D.Should the in now . FIG 7 If the hypotenuse d 0 shown is calculated from the coordinates (lat 1 , lon 1 ), (lat 2 , lon 2 ) of the two points P, P 0 , where "lat" stands for latitude and "lon" for longitude and "1", "2" symbolize the two different points P, P 0 on the globe, then the distance between the points P and P 0 , i.e. the distance d 0 to: d 0 = r archav hav θ , where hav θ = hav lat 2 − lat 1 + cos lat 1 ⋅ cos lat 2 ⋅ hav lon 2 − lon 1 . and substituting equation (4) into equation (3) finally gives the distance from d 0 , where r represents the Earth's radius.

[0065] As in connection with FIG 7 As explained, the opposite side dl and thus the longitudinal distance dl can be calculated from the hypotenuse d 0 and the lateral distance dr.

[0066] In FIG 10 A diagram is shown that documents a validation process. The diagram shows measured values, in this case measured longitudinal distances dl in meters (abbreviated as "m") between a rail vehicle 6 or a sensor unit 7 arranged on the front of the rail vehicle 6 and a test object 3, as a function of the measurement time t (the time is given in Coordinated Universal Time, "UTC"), represented by a solid, stepped line. Furthermore, the diagram also shows reference values ​​d lref for a longitudinal distance between the rail vehicle 6 or the sensor unit 7 and the test object 3, which are determined by measuring the self-localization units 4, 9 of the test object 3 and the rail vehicle 6, also represented by a solid line. The diagram further shows... FIG 10 A tolerance range T with a maximum deviation of the measured longitudinal distances dl of 10% from the respective reference value d lref is marked with dashed lines.

[0067] In FIG 11 Figure 1 illustrates a schematic representation of an arrangement 1 for validating a function of a sensor unit 7 of a rail vehicle 6 for object localization according to a second embodiment of the invention. In the FIG 11 In the arrangement shown (1), the test object (3) does not include the rail vehicle (6), but rather the validation unit (10). In this variant, unlike in the one shown in [reference missing], the test object (3) comprises... FIG 1 In the first embodiment shown, a receiving unit 5' is used to receive the absolute position AP of the test object 3 determined by the position determination unit 8. Furthermore, in contrast to the embodiment shown in FIG 1 In the first embodiment shown, the rail vehicle 6 has a transmitting unit 11' for transmitting the absolute position AP of the test object 3, determined by the position determination unit 8, to the test object 3. In this variant, a single validation unit 10 can be used for validating different rail vehicles, thus achieving a resource saving effect. The test object 3 also has, as in the one shown in FIG 1 In the first embodiment shown, a first self-localization unit 4 is provided, which transmits a determined reference position RP T of the test object 3 directly to the validation unit 10 encompassed by the test object 3.

[0068] In FIG 12 Figure 1 illustrates a schematic representation of an arrangement 1 for validating a function of a sensor unit 7 of a rail vehicle 6 for object localization according to a third embodiment of the invention.

[0069] In the third embodiment, the arrangement 1 includes a stationary evaluation unit 12 that is separate from the rail vehicle 6 and the test object 3. In this case, the stationary evaluation unit 12 comprises the validation unit 10 and a receiver unit 5'' for receiving the absolute position AP of the test object 3 determined by the position determination unit 8 of the rail vehicle 6. In the third embodiment, the receiver unit 5'' is also configured to receive the reference position RP T of the test object 3 from the test object 3 and to forward the received information AP, RP T to the validation unit 10. The stationary evaluation unit 12 can also be designed as a so-called remote computer and communicate with the test object 3 and the rail vehicle 6 via a communication network, for example, the Internet, in order to transmit the measurement data determined by the test object 3 and the rail vehicle 6.Information AP, RP T to be received. The rail vehicle 6 indicates at the in . FIG 12 In the third embodiment shown, a transmitting unit 11' is provided, similar to the second embodiment, for transmitting the absolute position AP of the test object 3, determined by the position determination unit 8, to the evaluation unit 12. The test object 3 in the third embodiment is constructed analogously to the test object 3 of the first embodiment. However, in the third embodiment, the transmitting unit 5 of the test object 3 does not transmit the information about the reference position RP T of the test object 3 to the rail vehicle 6, but rather to the separate stationary evaluation unit 12.

[0070] Finally, it should be noted once again that the methods and devices described above are merely preferred embodiments of the invention, which is defined by the independent claims. For the sake of completeness, it should also be noted that the use of the indefinite articles "a" or "an" does not preclude the possibility that the features in question may be present multiple times. Likewise, the term "unit" does not preclude the possibility that it consists of several components, which may also be spatially distributed.

Claims

1. Arrangement (1) for validating a function of a sensor unit (7) of a rail vehicle (6) for object localization, having: - a test railway line (2), - a test object (3) on the test railway line (2), comprising a first self-localisation unit (4) for determining a reference position (RPT) of the test object (3), - the rail vehicle (6), comprising: - a sensor unit (7) for detecting a relative position (RLP) of the test object (3) with respect to the sensor unit (7), - a second self-localisation unit (9) for determining an ego position (EP) of the rail vehicle (6), - a position determination unit (8) for determining an absolute position (AP) of the test object (3) on the basis of the detected relative position (RLP) of the test object (3) with respect to the sensor unit (7) and the determined ego position (EP) of the rail vehicle (6), - a validation unit (10) for determining a deviation (AW) of the determined absolute position (AP) of the test object (3) from the reference position (RPT) of the test object (3).

2. Arrangement according to claim 1, wherein the test object (3) has a transmit unit (5) for transmitting the determined reference position (RPT) of the test object (3) to the validation unit (10).

3. Arrangement according to claim 1 or 2, wherein the rail vehicle (6) comprises a receive unit (11) for receiving the determined reference position (RPT) of the test object (3).

4. Arrangement according to one of the preceding claims, wherein the rail vehicle (6) comprises the validation unit (10) .

5. Arrangement according to claim 1, wherein - the test object (3) has - the validation unit (10) and - a receive unit (5') for receiving the absolute position (AP) of the test object (3) determined by the position determination unit (8) and - the rail vehicle (6) has a transmit unit (11') for transmitting the absolute position (AP) of the test object (3) determined by the position determination unit (8).

6. Arrangement according to one of claims 1 or 2, having an evaluation facility (12) which is separate from the rail vehicle (6) and the test object (3), comprising: - the validation unit (10), - a receive unit (5'') for receiving the absolute position (AP) of the test object (3) determined by the position determination unit (8) and the reference position (RPT) of the test object (3), wherein the rail vehicle (6) has a transmit unit (11') for transmitting the absolute position (AP) of the test object (3) determined by the position determination unit (8).

7. Arrangement according to one of the preceding claims, wherein the first and / or the second self-localisation unit (4, 9) comprises at least one of the following types of self-localisation units: - a navigation unit for receiving a satellite navigation signal, - a receive unit for receiving RTK correction data, - an inertial measuring unit.

8. Arrangement according to one of the preceding claims, wherein the position determination unit (8) is designed to determined a path of a centre line (2a) of the test railway line (2) on the basis of the ego position (EP) of the rail vehicle (6).

9. Arrangement according to claim 8, wherein - the position determination unit (8) is designed to determine a distance (dr) of the test object (3) from the centre line (2a), and - the validation unit (10) is designed to determine a deviation (AW) of the determined distance (dr) of the test object (3) from the centre line (2a) from a reference distance of the test object (3) with respect to the centre line (2a).

10. Arrangement according to one of the preceding claims, wherein - the position determination unit (8) is designed to determine a longitudinal distance (dl) between the rail vehicle (6) and the test object (3), and - the validation unit (10) is designed to determine a deviation (AW) between the detected longitudinal distance (dl) between the rail vehicle (6) an the test object (3) and a longitudinal reference distance (dlref) between the rail vehicle (6) and the test object (3) determined on the basis of the reference position (RPT) of the test object (3) and the determined ego position (EP) of the rail vehicle (6).

11. Arrangement according to one of the preceding claims, wherein the test railway line (2) has a straight course.

12. Arrangement according to one of the preceding claims, wherein the test railway line (2) comprises a curvilinear course and a centre line (2a) of the test railway line (2) is approximated by straight line sections.

13. Method for validating a function of a sensor unit (7) of a rail vehicle (6) for object localisation having the steps: - determining a reference position (RPT) of a test object (3) by means of a first self-localisation unit (4) arranged on the test object (3), - detecting a relative position (RLP) of the test object (3) with respect to a sensor unit (7) arranged on the rail vehicle (6), - determining an ego position (EP) of the rail vehicle (6) by means of a second self-localisation unit (9) arranged on the rail vehicle (6), - determining an absolute position (AP) of the test object (3) on the basis of the detected relative position (RLP) of the test object (3) with respect to the sensor unit (7) and the determined ego position (EP) of the rail vehicle (6), - validating an object localisation of the sensor unit (7) by determining a deviation (AW) of the determined absolute position (AP) of the test object (3) from the reference position (RPT) of the test object (3).

14. Computer program product, comprising commands, which, upon execution of the program by a computer, trigger this to execute the steps of determining an absolute position (AP) of the test object (3) and validating the object localisation of the method according to claim 13.

15. Computer-readable storage medium, comprising commands, which, upon execution by a computer, trigger this to execute the steps of determining an absolute position (AP) of the test object (3) and validating the object localisation of the method according to claim 13.

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