Device and procedure for determining the position of a railway vehicle

Abstract

The invention relates to a sensor system (7) for determining the position of a railway vehicle (1). To improve this system, the invention specifies that the system (7) comprises at least two sensors (11) attachable to the railway vehicle (1), each designed to determine a position velocity and arranged at different positions on the vehicle (1) transversely to the direction of travel (5), and at least one processing device (12) connected to the sensors (11), designed to process the position velocities determined by them. The invention also relates to a method for determining the position of a railway vehicle (1).

Description

Device and procedure for determining the position of a railway vehicle Determining the position of a railway vehicle is a crucial task in rail traffic today, as the safety of a railway facility depends on it, among other things. Errors in determining the position of a railway vehicle could lead to risks or accidents with serious consequences for people and facilities. Position determination is often also referred to as odometry. Procedures of this kind for determining position are described, for example, in Ralph Glaus: "Kinematic track surveying by means of a multi-sensor platform", dated January 1, 2006. A rail guidance of a railway vehicle is known from document DE 102013001973 B3. Therefore, the object of the present invention is to provide an improved device for determining the position of a railway vehicle with a sensor arrangement and an improved procedure for determining the position of a railway vehicle. The object, according to the invention, is solved by means of the device for determining the position for a railway vehicle with a sensor arrangement according to claim 1 and the procedure for determining the position according to claim 10. The solution according to the invention offers the advantage that, by considering at least two position velocities, the determination of the railway vehicle's position is improved. On the one hand, position velocities can be used to verify a previously determined position of the railway vehicle, for example, using GNSS data. On the other hand, position velocities can be used as additional input variables to make a location result more accurate or precise, or, for example, position velocities can be used in the case of unfavorable conditions, such as very low speed or in a tunnel. For example, in satellite navigation systems, there is the problem that the GNSS data obtained from them can be altered due to so-called spoofing. This altered data due to spoofing can lead to incorrect calculations of the railway vehicle's position.This can be prevented by the solution according to the invention. Furthermore, the solution according to the invention can also be used to improve a location system without satellite navigation. Positional speed, as defined here, refers to the speed valid for a specific position on the rail vehicle, for which that position is measured or determined. In the case of travel around curves, a known external position on the rail vehicle has a different speed than an internal position. Therefore, different speeds prevail depending on the position, which are consequently referred to here as positional speeds. These speeds refer to the specific position. For example, if the speed is determined by an incremental displacement sensor mounted on a wheel, the speed applied is for the wheel's position transversely to the direction of travel. The sensor arrangement according to the invention, for determining position velocities, uses at least two sensors located on the railway vehicle. These sensors are positioned on the railway vehicle at different locations with respect to the direction of travel and determine a position velocity at each of those locations. From these at least two position velocities, a central velocity of the railway vehicle, which could also be called a reference velocity, can be determined as a calculation variable. This could be, for example, an angular velocity or an average velocity. In the procedure according to the invention, the position velocities are determined and used for determining the position of the railway vehicle. The invention relates to a device for determining the position of a railway vehicle, with at least one satellite navigation device that is designed to provide GNSS data. According to the invention, the device is equipped with at least one sensor arrangement as described above, and includes at least one verification device designed to verify the GNSS data provided by the satellite navigation device, or a position determined based on that data, using position velocities determined by the sensor arrangement. This offers the advantage that, for example, GNSS data altered by so-called spoofing can be detected directly, preventing an incorrect determination of the railway vehicle's position as a result. The solution according to the invention can be improved by advantageous configurations, as described below. Thus, at least one of the sensors, in an advantageous refinement of the sensor arrangement according to the invention, can be designed as an incremental displacement sensor connected to a wheel, where the wheel is not connected by a rigid axle to an opposing wheel transversely to the direction of travel. This offers the advantage that incremental displacement sensors are often already used in railway vehicles and, therefore, particularly for retrofitting, represent a cost-effective solution. It is important here that the wheel used for the incremental displacement sensor is independent and not connected to an opposing wheel by a rigid axle.Using a rigid axle, in the case of driving on curves, the incremental sensor values ​​would be altered, because on a curve the outer wheel travels a greater distance than the inner wheel, and this would be prevented by a rigid axle. For example, to be able to measure independently of the rail vehicle's wheels, at least one of the sensors can be designed as an optical or inductive sensor. An optical sensor, for example, could be a camera or a sensor that works on the principle of Spatial Filter Velocimetry. Optical sensors typically observe the railhead, while inductive sensors are frequently oriented towards the rail foot fixings, as these are easy to detect inductively. Both optical and inductive sensors detect the relative movement of the rail vehicle with respect to the track. Naturally, alternatively, one or both of the sensors can also be designed as Doppler radars. The sensors according to the invention are designed to determine a positional velocity. Positional velocity here refers to the relative movement of the railway vehicle at a given position with respect to the track or the ground. In this way, the sensors detect a distance traveled in a measured time and, based on this, determine the velocity in the usual manner. Furthermore, the sensors can be arranged transversely to the direction of travel, essentially directly opposite it. This offers the advantage that the sensors' determined position velocities can be easily used for position verification. In particular, in optical or inductive sensors, to ensure good visibility towards the track below the vehicle, the sensors, viewed in the direction of travel, can be arranged between two wheels of the railway vehicle. In another advantageous configuration, the sensors can be arranged transversely to the direction of travel, essentially equidistant from the center of the rail vehicle. Here, the center of the rail vehicle is assumed to be the same as the center between the wheels. The center, therefore, lies at the midpoint between the rails. Thus, to determine the average speed, one can simply consider the average of the two positional speeds. Furthermore, the sensor array can be designed to determine the angular velocity of the rail vehicle. Using angular velocity is advantageous because it can be directly compared to an angular velocity calculated from GNSS data. Alternatively, a trajectory can also be calculated from the angular velocity and then compared to a trajectory calculated from GNSS data. Additionally, the sensor array can be designed to determine the angular velocity of the rail vehicle using the formula where v1 and v2 are position velocities determined by the sensors and yr is a distance from the sensors, from one with respect to the other. The sensor array can also be designed to determine the average speed of the rail vehicle. Average speed is considered to be the speed of the rail vehicle at its center. On a rail vehicle, the wheel on the inside of a curve rotates at a lower speed, and the wheel on the outside of a curve rotates at a higher speed than at the center of the vehicle. The average speed is the speed at the center of the rail vehicle. If a sensor is used on the side of the vehicle, the slip detection algorithms could be activated on curves, which would be undesirable. For example, the vehicle could then be incorrectly operated at a lower speed, and its route would not be followed. According to the invention, the verification device is designed to compare an angular velocity determined by GNSS data with an angular velocity determined by the sensor arrangement, and to initiate action if a difference between the two angular velocities exceeds a predetermined limit value. Furthermore, the present invention relates to a railway vehicle that has at least one device according to the invention for determining position according to one of the aforementioned embodiments. In an advantageous configuration of the procedure according to the invention, an angular velocity and / or an average speed of the railway vehicle can be determined. This offers the same advantages already described, as in the corresponding embodiment of the sensor arrangement according to the invention. To verify the position using a satellite navigation system, according to the invention, GNSS data is provided from at least one satellite navigation device of the railway vehicle and the GNSS data, or a position determined based on the same, is verified by the position velocities determined by the sensor arrangement. The invention is then explained with reference to the attached drawing. The single figure shows a schematic representation of an example execution form of a railway vehicle according to the invention. The figure shows an exemplary embodiment of a railway vehicle 1 according to the invention, which forms part of a railway installation 2. Together with the railway vehicle 1, the railway installation 2 also comprises a track 3 with rails 4 on which the railway vehicle 1 travels in a direction of travel 5. The railway vehicle 1, for example, can be a long-distance train, a freight train, a regional train, a subway, or a tram and is embodied in a known manner. Thus, the railway vehicle 1 comprises a plurality of wheels 6, of which only some are shown for illustrative purposes, which are in contact with the rails 4 in a known manner. Furthermore, the railway vehicle 1 comprises at least one sensor arrangement 7 and a satellite navigation device 8. The satellite navigation device 8 is equipped in a known manner and, based on signals from satellites 9, determines GNSS data, from which the position of railway vehicle 1 can be determined. The abbreviation GNSS stands for Global Navigation Satellite System. Well-known examples of satellite navigation systems based on GNSS include the European Galileo system, the North American GPS system, and the Russian GLONASS system. The position of railway vehicle 1 can be determined from the GNSS data determined by the satellite navigation device 8. This can be done directly from the satellite navigation device 8 or via a computing unit 10 located on railway vehicle 1. The computing unit 10, for example, could be part of an onboard computer.However, the position of rail vehicle 1 determined using GNSS data may be incorrect. For example, this can happen due to so-called spoofing, where incorrect position data is determined because of interference signals. To solve this problem, the railway vehicle 1 according to the invention features sensor arrangement 7. Sensor arrangement 7 comprises two sensors 11 and a processing device 12. The sensors 11 are respectively designed to determine a position speed and are arranged in different positions on the railway vehicle 1. Position speed is understood here as the speed determined by the respective sensor 11 for a given position on the railway vehicle 1, relative to track 3. The sensors 11, for example, can be designed as incremental displacement sensors connected to a wheel 6, optical sensors, or inductive sensors. In the embodiment as an incremental displacement sensor, it is connected to a wheel 6 of the rail vehicle 1, such that the incremental displacement sensor detects the movement of the wheel 6 and, consequently, the speed at the position of the wheel 6 can be determined. The incremental displacement sensor must be arranged on a wheel 6 that is not connected by a rigid axle to the corresponding opposite wheel 6, transversely with respect to the direction of travel 5. Otherwise, the measured position speed would be altered on a curve. In an embodiment as an optical sensor, it, for example, detects the movement of the rail vehicle 1 at the corresponding position, relative to the railhead, of the corresponding rail 4.In its implementation as an inductive sensor, it can, for example, detect the rail foot fixings that have been passed and thus the path traveled and the position speed. Ideally, the sensors 11 are arranged directly opposite each other, transversely with respect to the direction of travel 5 and at the same distance from a center 13 of the railway vehicle 1. In the example embodiment shown in the figure, the sensors 11, in addition to being observed respectively in the direction of travel 5, are arranged between two wheels 6 of the railway vehicle 1. In this case, the sensors 11 are essentially in the same line as the wheels 6, so that the sensors 11 are respectively arranged on the respective rail 4 of track 3. The sensor arrangement 7 according to the invention, based on the position velocities v1, v2, determines an angular velocity of the railway vehicle 1. The angular velocity can be determined using the formula where v1 and v2 are the position velocities determined by the sensors, and r is the distance between the sensors. The angular velocity can be determined either by the sensor array 7 itself or by the calculation unit 10. The calculation unit 10 can then, for example, use the angular velocity determined by the sensor array 7 to verify the GNSS data from the satellite navigation device 8. From the GNSS data, an angular velocity of the railway vehicle 1 can also be determined. The two determined angular velocities can then be compared. A verification device 14 is configured within the calculation unit 10 for this purpose, designed to verify the GNSS data provided by the satellite navigation device 8 or a position determined based on it.Verification device 14 triggers an alarm if a difference between the angular velocity determined based on GNSS data and the angular velocity determined from position velocities exceeds a predetermined limit value. The sensor arrangement 7, the satellite navigation device 8 and the verification device 14 together form a device 15 according to the invention for determining the position for the railway vehicle 1. The sensor arrangement 7 according to the invention can also be used to determine an average speed. In the case of a railway vehicle 1, when traveling around curves, the speed at the position of the wheels on the inside of the curve is lower and at the position of the wheels on the outside of the curves 6 is higher than the average speed at the center 13. Therefore, the average speed can be used advantageously because it is not altered when traveling around curves.

Claims

1. A device (15) for determining the position of a railway vehicle (1), comprising at least one satellite navigation device (8) designed to provide GNSS data, and comprising at least one sensor arrangement (7) for determining the position of the railway vehicle (1), wherein the sensor arrangement (7) comprises at least two sensors (11) that can be placed on the railway vehicle (1), which are respectively designed to determine a position velocity and are arranged on the railway vehicle (1) in different positions transversely with respect to the direction of travel (5), and comprises at least one processing device (12) designed to process the position velocities determined by the sensors (11), wherein the sensor arrangement (7) is designed to determine an angular velocity of the railway vehicle (1),characterized in that the device (15) comprises at least one verification device (14) designed to verify the GNSS data provided by the satellite navigation device (8) or a position determined based thereon, and the verification device (14) is designed to compare an angular velocity determined by the GNSS data with the angular velocity determined by the sensor arrangement (7) and to initiate an action if the difference between the two angular velocities exceeds a predetermined limit value.

2. Device (15) according to claim 1, characterized in that at least one of the sensors (11) is designed as an incremental displacement sensor connected to a wheel (6), wherein the wheel (6) is not connected by a rigid axle to a wheel (6) transversely opposite with respect to the direction of travel (5).

3. Device (15) according to claim 1 or 2,characterized in that at least one of the sensors (11) is designed as an optical or inductive sensor.

4. Device (15) according to any one of the aforementioned claims, characterized in that the sensors (11) are arranged transversely with respect to the direction of travel (5), essentially directly opposite each other.

5. Device (15) according to any one of the aforementioned claims, characterized in that the sensors (11), viewed in the direction of travel (5), are arranged between two wheels (6) of the railway vehicle (1).

6. Device (15) according to any one of the aforementioned claims, characterized in that the sensors (11) are arranged transversely with respect to the direction of travel (5), essentially equidistant from a center (13) of the railway vehicle (1).

7. Device (15) according to any one of the aforementioned claims,characterized in that the sensor arrangement (7) is designed to determine the angular velocity of the railway vehicle (1) using the formula where v1 and v2 are position velocities determined by the sensors (11) and r is the distance between the sensors (11).

8. Device (15) according to any one of claims 1 to 6 above, characterized in that the sensor arrangement (7) is designed to determine an average velocity of the railway vehicle (1).

9. Railway vehicle (1), characterized in that the railway vehicle (1) has at least one device (15) for determining position according to any one of the claims above.

10. Method for determining the position of a railway vehicle (1), wherein at least two position velocities are determined at respectively different positions of the railway vehicle (1) with respect to the direction of travel, wherein the at least twoPosition velocities are processed and used for determining the position of the railway vehicle (1), and wherein an angular velocity of the railway vehicle (1) is determined, characterized in that at least one satellite navigation device (8) of the railway vehicle (1) provides GNSS data, and the GNSS data or a position determined based thereon is verified, wherein an angular velocity determined by the GNSS data is compared with the angular velocity determined by the sensor arrangement (7) and an action is initiated if a difference between the two angular velocities exceeds a predetermined limit value.

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