Method and system for determining a nominal geometry for position correction

Abstract

The invention relates to a method for determining a target geometry (S) of a track (5) for a position correction of the track (5), wherein initially an actual geometry (I) of the track (5) is surveyed on a track section (26) by means of a surveying system (8), and wherein subsequently a calculation of the target geometry (S) is carried out by means of a computing unit (36) on the basis of the actual geometry (I). Here, a plurality of actual position points (15) of the track (5) are surveyed along the track section (26) by means of a position detection system (13), at least one actual position point (15) is preset as a constraint point (24) by the computing unit (36), and the target geometry (S) is calculated by means of the computing unit (36) on the basis thereof, the target geometry (S) corresponding to the actual geometry (I) as a sequence of geometric course elements (31, 32, 33) and being routed past the preset constraint points (24). As a result, a clear quality improvement is achieved compared to known compensation methods with a pre-determined surveying.

Description

TECHNICAL FIELD

[0001] The invention relates to a method for determining a target geometry of a track for a position correction of the track, wherein an actual geometry of the track is first measured on a track section by means of a measuring system, and wherein a compensation calculation is subsequently carried out by means of a computing unit in order to calculate the target geometry on the basis of the actual geometry. Furthermore, the invention also relates to a system for carrying out the method. BACKGROUND

[0002] On ballast tracks, the local position of the track superstructure arranged in the ballast is influenced by driving over the track and by weather factors. Therefore, in order to check the current track geometry (line profile of the track) and especially before maintenance work, regular measurements are carried out by means of a self- equipped measuring car. Correspondingly configured track superstructure engineering machines can also be used as measuring cars. Usually, the track geometry is defined by the horizontal position (direction) and the vertical position (track inclination). Furthermore, the position relative to an external reference system is required in order to determine the absolute track geometry.

[0003] The known measuring methods use external reference points located next to the track, which are arranged on fixed devices, such as telegraph poles. Such external reference points can be determined as marker pins or other markers. Likewise, topographic surveying systems or GNSS systems (Global Navigation Satellite System) can be used to determine the external reference points. The set position of each external reference point for the track is registered in a catalog. In this way, the determined track geometry (= design geometry of the track) is precisely defined on the main track of the railway.

[0004] Furthermore, the target geometry of the track can be determined by means of the external reference points. Here, the line is specified in terms of length and size by a sequence of line elements. In the case of straight lines, the length is sufficient. Transition arcs and circular arcs are determined by providing the length and the arc length, respectively. So-called track control points provide the alternating positions between different line elements, especially for circular arcs and transition arcs as well as for inclination breaks.

[0005] The horizontal position of the track thus consists of the track curve as a series of straight sections, transition arcs and circular arcs. The vertical position of the track is determined by the provided inclination and the grade change points together with their radii of the circular angles. The super-elevation profile of the track is determined by its super-elevation profile, which includes super-elevation slopes. In determining the track geometry, the super-elevation and the direction of the track are coordinated with each other according to line guidelines (e.g. EN 13803).

[0006] The desired track position with high quality is again established by the so-called precision method. In this method the precise, absolute track geometry (design geometry) is known by a series of defined line elements and by the topographical position of the track control points. Prior to the maintenance process, the existing track geometry and track position are measured relative to defined reference points (fixed points, positioning points). The measurement results are compared to one another with the design geometry, wherein from the resulting differences the lifting and calibration values for the track position correction are determined. This method is very accurate and is suitable for high-speed sections which require optimized maintenance work. Here, the geographical parameters must be processed reliably and the geographical reference points must be regularly re-measured.

[0007] For cost reasons, the so-called compensation method is used in sections of the track with lower demand. This method can be implemented without a known design geometry of the track. For example, the measurement system of a track tamping machine is used, wherein a measuring chord (travel chord) is tensioned between the measuring cars which are guided on the track and serves as a reference system. Different types of this travel chord measurement principle are provided, for example, in the document DE 10 2008 062 143 B3 or in the document DE 103 37 976 A1. The existing track position errors are reduced here in proportion to the tensioned width of the measuring chord relative to the longitudinal distance of the measuring cars. In the 4-point method, the relative track geometry which is formed is taken by additional measuring chords. The corresponding machine and method are disclosed in the document AT 520 795 A1.

[0008] In the compensation method with prior track measurement, the existing respective actual track geometry of the track is measured by a track tamping machine or a measuring car which is driven through beforehand. For this purpose, so-called inertial measurement units (IMU) are used in modern track measurement vehicles. Inertial measurement units are described in the specialist document "Railway Engineering" (52) September 2001, pages 6-9. The document DE 10 2008 062 143 B3 also discloses an inertial measurement principle for detecting the track position. Based on this measurement, the compensation calculation is implemented, wherein the not previously known nominal geometry is calculated based on the actual geometry.

[0009] In general, the actual geometry of the track is detected in the form of a deflection curve and a longitudinal height curve as well as a sequence of superelevation values. Based on this recording, an electronic deflection compensation is calculated by a calculation unit taking into account the previously determined speed class of the track as well as the upper limit of the pre-set travel values and lifting values. Here, the measured deflection is smoothed in order to obtain the most ideal curve progression possible for the given conditions. In the course of the compensation calculation, the position of the transition points between the plurality of line elements (track control points) is determined.

[0010] In a next step, the calculated deflection is compensated by using a digital filter to calculate a synthetic movement and lift, so that the track has to be corrected, whereby the calculated deflection curve can be adjusted. As a result, additionally calculated are lift correction values (correction values) for the track position correction values of the track tamping machine.

[0011] The repeated application of the compensation method has the disadvantage that the track control points are displaced from their (initially determined) initial position according to the design geometry. As a result, due to the aging of the track, despite the correction by means of the compensation method, an ever-increasing deviation from the initial design geometry results.

[0012] Small positional changes of the track control points are usually not problematic. For the fixation of the track position, the line is usually designed with sufficient clearance. However, difficulties arise at so-called constraint points or constraint positions, for example, bridges, tunnels or railway crossings. At those places, there is no clearance for the movement of the track. Therefore, according to the prior art, the movement values are usually set to zero in the compensation calculation at these positions. SUMMARY

[0013] The technical problem addressed by the present invention is to improve the method of the aforementioned type in such a way that the preset nominal track geometry has a higher quality compared to the compensation method. Furthermore, the technical problem addressed by the present invention is to provide a corresponding system.

[0014] The technical problem is solved according to the invention by a method for determining a nominal geometry of a track for the correction of the position of the track and a system for carrying out the method of the aforementioned type.

[0015] It is provided here that a plurality of actual position points of the track are measured along the track section by means of a position detection system, at least one actual position point being preset as a constraint point by the calculation unit, and that a nominal geometry is calculated by means of the calculation unit by compensation, which corresponds to the actual geometry as a sequence of geometric line elements and is laid out through the preset constraint points. On the basis of this calculation, the actual geometry of the track (relative to the track) is obtained. The line elements are filtered in the measurement scenario of the track. The measured actual position points (track position track) are taken into account as a second basis in the compensation calculation for the lift correction values. Here, each actual position point is determined by means of coordinates in a spatial reference system. For example, a coordinate system with a fixed position of the starting point of the measurement drive is chosen as the origin. Other coordinate systems for the topographical reference can also be used at present.

[0016] Thus, in contrast to the precise method, no association with fixed external reference points and thus with the design geometry is established. No absolute pre-determination (measurement) of the track is involved here. The method according to the application can be implemented in an efficient and inexpensive manner with simple technical means, although a lower precision is to be expected in relation to the precise method.

[0017] A clear quality improvement is achieved in comparison with the known pre-determined compensation method. At the constraint points, the correction values are not simply set to zero. According to the application, the overall calculated nominal geometry is matched to at least one pre-set constraint point by means of which a defined geometric course element of the optimization is set.

[0018] In a refinement of the method, it is provided that fixed track points in their position are automatically recognized by means of a sensor device, and that the actual position points associated with the recognized fixed track points are pre-set as constraint points by means of a pre-setting device. The sensor device comprises, for example, an optical sensor with pattern recognition in order to recognize the typical structure of a railway crossing or a bridge. Technically fixed track points in their position can also be recognized by optical markers and other passive or active markers in order to enable simple automatic recognition by means of a sensor.

[0019] Alternatively or additionally in relation thereto, in a simple solution the actual position points are pre-set as constraint points by an operator by means of a pre-setting device. An operator is present, for example, in a measuring vehicle for measuring track sections. As soon as the operator recognizes that a curve turnout, a bridge without ballast or a railway crossing with rigid cover plates is driven over, the currently measured actual position point is pre-set as a constraint point. The constraint points can also be pre-set retrospectively on the basis of image symbols with associated coordinates.

[0020] It is further refined that the actual position points are measured as GNSS coordinates by means of a GNSS receiving device. The system used here is as fail-safe as possible and provides results with sufficient precision.

[0021] It is meaningful here that the reception of the actual position points is implemented by means of a differential GNSS system in order to increase the precision of the position data if necessary.

[0022] In an advantageous embodiment of the method, the actual geometry of the track is measured by means of an inertial measurement unit, wherein, in particular, a time stamp is pre-set as a common time base for each measurement data by means of the inertial measurement unit. Inertial measurement units are very robust against external disturbances and provide very precise data for the measurement of the actual geometry for the application. If the inertial measurement unit provides a time base for the synchronization of the data, it is very meaningful for the calibration of the data with the position detection system.

[0023] In an advantageous embodiment of the application, a three-dimensional trajectory is derived in the evaluation device from the measurement data of the inertial measurement unit, and a correction value for the position correction of the track is derived from the calibration of the actual geometry. Here, the three-dimensional trajectory and the nominal geometry relate to a common coordinate system, whereby the correction value can be determined with a lower computational effort. The derived three-dimensional trajectory is also suitable for recording the state of the track before the track correction in a visual manner.

[0024] It is also meaningful to determine a suitable three-dimensional trajectory for the left-hand rail of the track and for the right-hand rail of the track, respectively. Thereby, it is possible to detect, in a simple manner, in particular a superelevation error of the track or individual errors of the tracks with different settlements. Subsequently, the calculation of the nominal geometry takes these properties into account, for example by compensating for individual errors.

[0025] In a further advantageous embodiment, it is provided that unfiltered measurement data of the measured track section from the inertial measurement unit are transmitted to the evaluation device, a virtual inertial measurement of the same track section with the nominal geometry is simulated by means of a simulation device in order to obtain simulated measurement data in the case of the nominal geometry, and the simulated measurement data are subtracted from the unfiltered measurement data of the inertial measurement unit in order to derive the correction value for the position correction of the track. Pseudo-traces can occur in the unfiltered measurement data when using the inertial measurement unit, in particular when driving on curves. Such pseudo-traces are caused by specific characteristics of the used inertial measurement method. If the same inertial measurement method is used in a virtual form with respect to the nominal geometry at this point in time, the same pseudo-traces occur. In order to derive the correction value, the pseudo-traces cancel each other out by subsequently subtracting the unfiltered measurement data. Thereby, the overall required computational effort is reduced, since an occasional cumbersome numerical filtering of the measurement data is dispensed with.

[0026] In a further refinement of the method, at least one measured actual position point is determined as a constraint point for the compensation calculation, which at least one measured actual position point does not lie between the start point and the end point of the construction section provided for the position correction. Thereby, it is ensured that the derived nominal geometry in the current construction section also contributes to the quality of future track corrections in the adjoining track sections. Thereby, the maintenance of the track sections beyond the construction section is taken into account.

[0027] According to the invention, a system for carrying out the aforementioned method is specified, the system having a measuring locomotive for driving over a track section, the measuring locomotive comprising a measuring system for taking the actual geometry of the track, and the system further having a computing unit for calculating a target geometry on the basis of the actual geometry, wherein the measuring locomotive comprises a position detection system for detecting a plurality of actual position points along the track section, wherein a presetting device for the computing unit is provided for presetting at least one actual position point as a constraint point, and wherein an algorithm is configured in the computing unit which corresponds the target geometry to the actual geometry as a sequence of geometric track elements and sets the target geometry by means of at least one constraint point. In this way, a plurality of components of the system are made to interact in order to detect the actual geometry and the actual position points and to derive therefrom the target geometry for the track position correction.

[0028] In a refinement of the system, the measuring locomotive has a sensor device for automatically recognizing fixed track points in its position, wherein the sensor device is coupled to the presetting device in order to determine the actual position points which are assigned to the track points as constraint points. The sensor device comprises, for example, a plurality of coupled sensors with different characteristics in order to detect physical objects of the track and to classify them. A corresponding method is described in the document AT 518692 A1 of the same applicant. As soon as an object is classified as a fixed track point of the construction technology (bridge, railway crossing, etc.), the presetting device specifies the corresponding actual position point as a constraint point. Alternatively or additionally thereto, sensor markers can be arranged at these track points.

[0029] A simple refinement provides that the presetting device comprises an operating unit by means of which an actual position point can be determined as a constraint point by an operating person. The operating unit comprises, for example, an operating element which, when actuated, presets the currently taken actual position point as a constraint point.

[0030] Advantageously, the position detection system comprises a GNSS receiving device which is coupled, in particular, to a position measuring device in order to determine the position of the GNSS receiving device relative to the track. Thereby, a stable and sufficiently precise determination of the actual position points can be carried out in a geodetic reference system.

[0031] Furthermore advantageously, the measuring system comprises an inertial measuring unit and, in particular, a position measuring device for determining the position of the inertial measuring unit relative to the track. Such a measuring system detects the actual geometry contactlessly, whereby a high speed can be achieved when measuring driving. Since the GNSS receiving device also provides the results in real time, a high operating speed of the entire system is achieved overall.

[0032] The system provides that the evaluation device is further improved in that for the correction of the track position there is provided an evaluation device for calculating correction values, wherein there is provided a control device for the track superstructure engineering machine for processing the correction values, in order to bring the track into the preset nominal geometry by means of the controlled lifting calibration device. The system in this way comprises all components in order to detect the actual geometry and to implement the correction of the track position on the basis thereof. BRIEF DESCRIPTION OF DRAWINGS

[0033] The application is explained below by way of example with reference to the drawings. In the drawings:

[0034] Figure 1 Schematic representation of a measuring locomotive on a track

[0035] Figure 2 Schematic representation of a scene showing a construction section and a measuring section

[0036] Figure 3 Block diagram showing the determination of correction values

[0037] Figure 4 Schematic representation of a track extension profile

[0038] Figure 5 Schematic representation of a track curve with a transition arc and a straight line

[0039] Figure 6 Schematic representation of a scene showing a track section with an actual geometry and a nominal geometry DETAILED DESCRIPTION

[0040] Figure 1 A measuring locomotive 1 is shown with a locomotive frame 2, on which a carriage 3 is constructed. The measuring locomotive 1 is able to travel on a track 5 by means of a rail running gear 4. For better illustration, the locomotive frame 2 together with the carriage 3 is shown lifted from the rail running gear 4. The locomotive 1 can also be designed as a track superstructure engineering machine, in particular as a tamping machine. In this case only the machine for measuring and for correcting the track 5 is required.

[0041] The rail running gear 4 is preferably designed as a bogie. A measuring frame 6 is connected to the wheel axle of the bogie, so that the movement of the wheels is transmitted to the measuring frame 6 without spring action. As a result, there is only lateral movement or oscillation of the measuring frame 6 relative to the track 5. This movement is measured by means of a position measuring device 7 arranged on the measuring frame 6. The position measuring device is for example designed as a laser line intersection sensor.

[0042] The position measuring device 7 is a component of a measuring system 8 mounted on the measuring frame 6, which measuring system comprises an inertial measuring unit 9. The measuring data of the track 10 are taken by means of the inertial measuring unit 9 during the measuring run, wherein the relative movement of the inertial measuring unit 9 with respect to the track 5 is compensated by means of the data of the position measuring device 7. In this way the taking of the actual geometry I of the track 5 is achieved. Furthermore, the measuring data of the inertial measuring unit 9 on the individual rails 11 of the track 5 can be converted by means of the measuring data of the position measuring device 7. The result is a track 10 for each rail 11.

[0043] The measuring locomotive 1 further comprises a position detection system 12 by means of which the current position of the measuring locomotive 1 can be taken. Thereby, the position of the currently driven track point can also be detected in dependence on the known position of the measuring locomotive 1 with respect to the track 5. The position detection system 12 comprises, for example, a GNSS receiving device, which is rigidly connected to the locomotive frame 2 by means of a bracket 13. The GNSS receiving device comprises a plurality of GNSS antennas 14 arranged relative to one another for the exact taking of the GNSS position of the measuring locomotive 1. In order to detect the oscillation of the locomotive frame 2 with respect to the track 5, the position measuring device 7 is also arranged on the locomotive frame 2. Here too, for example, a laser line intersection sensor 7 can be used. For the simple implementation of the application, the GNSS antennas 14 are sufficient. In this way the position points 15 of the track 5 or of the track center axis 16 are continuously detected.

[0044] An alternative position detection device 12, not shown, comprises a radio-based measuring system for real-time positioning. Here, a plurality of transmitter modules are arranged on the measuring locomotive 1. Reference stations located next to the track section comprise transponders. By continuously carrying out distance measurements between the transmitter modules and the transponders, the position of the measuring locomotive 1 and thus the position of the currently driven track point with respect to the reference stations can be determined. The reference stations are used only for positioning without reference to the original design shape of the track 5.

[0045] Furthermore, the measuring locomotive 1 comprises a sensor device 17 for the automatic recognition of track points 18, 19 which are fixed in their position in terms of construction. Figure 2 The sensor device 17 advantageously comprises a plurality of sensors 20, 21, 22, the data of which are jointly evaluated. For example, a camera 20, a rotating laser scanner 21 and an infrared camera 22 with infrared illumination can be used. The sensor device 17 is coupled to a preset device 23 in order to determine the actual position points 15 which belong to the fixed track points 18, 19 as constraint points 24. Alternatively or additionally to the sensor device 17, the preset device 23 can comprise an operating unit 25. By means of the operating unit 25 the actual position points 15 can be preset as constraint points 24 by an operator.

[0046] In Figure 2 The track 5 driven over by the measuring locomotive 1 is shown. The dotted profile marks the length of the track section 26 on which the actual geometry I and the actual position points 15 of the track 5 are detected. The dashed profile marks the length of the construction section 27 on which the track 5 is subsequently corrected. The construction section 27 is shorter than the measured track section 26 and is limited by the start point 28 and the end point 29.

[0047] On the shown track section 26 there are two line points 18, 19 which are fixed in their position with respect to construction. This relates here for example to a line crossing 18 with a rigid cover layer and a bridge 19 without ballast bed. The bridge 19 is located outside the construction section 27. The actual position points 15 assigned to the line points 18, 19 are determined as constraint points 24 when driving the measurement.

[0048] In the shown example a position-fixed coordinate system XYZ is used for the coordinate setting of the measurement results, which has the coordinate origin of the coordinate system at the start point of the measurement drive. The X-axis shows the north direction, the Y-axis the east direction and the Z-axis the downward direction. Furthermore, a travel s is measured when driving the measurement, which can be used for the synchronization of the measurement results of the different systems 8, 12, 17 in addition to the time stamp.

[0049] Along the track section 26 there are line control points 30. The line control points 30 mark the border between the straight line 31 and the transition arc 32 and between the transition arc 32 and the circular arc 33, respectively. The straight line 31, the transition arc 32 and the circular arc (complete curve) 33 are defined here as geometric line elements.

[0050] Figure 3 The block diagram in shows the individual method steps. First a preliminary determination 34 is carried out, by which the relative actual geometry I and the GNSS position P of the track 5 are detected. As a result the measurement data of the inertial measurement unit 9 and the coordinate data for the measured actual position points 15 are presented.

[0051] Subsequently a compensation calculation 35 is carried out by means of an optimization algorithm provided in the calculation unit 36, in particular a track position optimization 37, by which the track geometry is composed from the sequentially arranged geometric line elements 31, 32, 33 on the basis of the actual geometry I in order to remove the track attitude errors. The optimization process 37 is realized according to the track position optimization 38 in such a way that the line elements 31, 32, 33 are sequentially arranged and dimensioned in such a way that the nominal geometry S of the track 5 is derived by the preset constraint points 24.

[0052] The marginal conditions for these optimization processes 37, 38 constitute the connection locations at the boundaries of the construction section 27. In particular, the nominal geometry S must be routed through the start point 28 and the end point 29 of the construction site. Furthermore, the nominal geometry S extends tangentially to the untreated track 5 at these points 28, 29. An optimization algorithm, for example, optimizes the deviation between the nominal geometry S and the actual geometry I as an objective function with the additional conditions provided (method of least squares).

[0053] By means of the nominal geometry S preset by the method, correction value calculations 39 are carried out in the following steps. This is achieved in the first variant by means of a three-dimensional trajectory 10, which is derived from the measurement data of the inertial measurement unit 9. The actual geometry I of the track 5 is derived from the coordinates of the trajectory 10, so that the correction values can be directly derived from the correction relative to the nominal geometry S. These are typically movement values for lateral adjustment and for lifting the track panels (adjustment values) and lifting values. Preferably, an individual lifting value is preset for each rail 11 in order to compensate for individual errors, for example, or to adjust the super elevation. The correction values are determined by means of an evaluation device 40, which references the values of the actual geometry I of the track 5 and the nominal geometry S.

[0054] In the second variant, unfiltered measurement data of the inertial measurement unit 9 are used. The necessity of deriving the coordinates of the trajectory 10 by means of correction data calculations 39 is thereby eliminated. Instead, a simulation process is implemented in the evaluation device 38, in which the inertial measurement is simulated. On the basis of a real measurement of the track section 26 by means of the real inertial measurement unit 9, a virtual measurement of the same track section 26 is carried out by means of the calculated nominal geometry S. A virtual inertial measurement unit is used here. The same inertial measurement method is used for both the real measurement unit and the virtual measurement unit. The artifacts associated with the method occur both in the real measurement and in the virtual measurement. These artifacts are eliminated by subtracting the measurement data of the actual geometry I and the nominal geometry S obtained. As a result, the correction values for the respective track section 26 are obtained.

[0055] The correction values are preset to a control device of a lifting calibration device of a tamper machine. The tamper machine can be designed at the same time as the measuring locomotive 1 described here. In order to correct the track geometry, the track 5 is driven over after the measurement by means of the tamper machine. On the basis of the preset correction values, the track panels are brought to their desired position by means of the lifting calibration device and are determined here by means of the tamper device. A chord measurement system is used to check the track position, which is installed on the tamper machine. A so-called track geometry-guidance computer (also known as automatic guidance computer ALC) in the tamper machine comprises the calculation unit 36 and the evaluation device 40. The guidance computer serves here as a central unit for determining the correction values and for controlling the tamper machine.

[0056] Figure 4 In the upper two diagrams, a curve of the curvature (curvature diagram) and a curve of the superelevation (superelevation diagram) are shown. The path s is shown on the abscissa. On the ordinate of the curvature diagram, the current curvature or the direction r on the path s is shown. On the ordinate of the superelevation diagram, the superelevation or the height h on the path s is shown.

[0057] In the lower part, the assigned scenario of the track section 26 is shown in a position-fixed coordinate system XYZ with X and Y coordinates. The shown track section starts with a straight line 31 and then transitions into a transition arc 32 with a rising curvature, until the curvature remains constant in the following circular arc (full curve) 33.

[0058] The measured actual geometry I is shown by a dashed line in the curve diagram and in the scenario diagram. It can be clearly seen that there is no unambiguous position of the route control point 30 for the to-be-determined nominal geometry S. Two variants are shown here, which differ in the length of the transition arc 32 and thus in the nominal geometry S. The method according to the application makes use of this gap space in order to achieve an optimized sequence of the geometric route elements.

[0059] In Figure 5 The curvature diagram, the superelevation diagram and the scenario diagram are also shown in

[0060] According to Figure 6 It is shown that a constraint point 24, which is preset outside the construction point, also advantageously influences the nominal geometry S in the construction section 27. A scenario diagram of the track section 26 is shown here, on which the pre-measurement is carried out by the measuring vehicle 1. The measured actual geometry I is shown by a lighter solid line. The dotted line shows a possible nominal geometry according to the conventional compensation method. Here, the actual geometry I is only smoothed. It can be clearly seen that the marked constraint point 24 misses the fixed route point 18, for example a railway crossing.

[0061] In the method according to the application, the coordinates of the constraint points 24 are included in the calculation of the nominal geometry S. In this way the sequence of the geometric line elements marked in solid lines is derived. The line control points 30 also provide the boundaries of the line elements. In the example shown, the track 5 with the transition arcs 32, which is corrected according to the conventional compensation method, is connected to the untreated track.

[0062] In the method according to the application, the track 5 is extended at the said location as a longer straight line 31 due to the added constraint points 24. The connection angle and the position coordinates of the track 5 at the end point 29 of the construction site remain the same. Thereby it is ensured that an ideal result is achieved when the further track extension is subsequently corrected. In Figure 6 The extension of the track 5 is shown strongly exaggerated in order to make the said effect clear.

Claims

1. A method of determining a nominal geometry (S) of a track (5) for a position correction of the track (5), wherein, First, the actual geometry (I) of the track (5) is measured on the track section (26) by means of the measuring system (8), and wherein subsequently, the calculation of the target geometry (S) is carried out by means of the computing unit (36) on the basis of the actual geometry (I), characterized in that a plurality of actual position points (15) of the track (5) are measured along the track section (26) by means of the position detection system (13), at least one actual position point (15) being preset as a constraint point (24) by the computing unit (36), and in that the target geometry (S) is calculated by means of the computing unit (36) as a sequence of geometric course elements (31, 32, 33) corresponding to the actual geometry (I) and being routed through the preset constraint points (24).

2. The method according to claim 1, characterized in that A fixed course point (18, 19) in its position is recognized automatically by means of the sensor device (17), and an actual position point (15) associated with the recognized fixed course point (18, 19) is preset as a constraint point (24) by means of the presetting device (23).

3. The method of claim 2, wherein, An actual position point (15) is preset as a constraint point (24) by an operator by means of the presetting device (23).

4. The method of claim 1, wherein, The actual position points (15) are measured as GNSS coordinates by means of a GNSS receiving device.

5. The method of claim 4, wherein, The reception of the actual position points (15) is carried out by means of a differential GNSS system.

6. The method of claim 1, wherein, The actual geometry (I) of the track (5) is measured by means of an inertial measuring unit (9).

7. The method of claim 6, wherein, A time stamp is preset as a common time base for each measurement data by means of the inertial measuring unit (9).

8. The method of claim 6, wherein, In the evaluation device (40), a three-dimensional trajectory (10) is derived from the measurement data of the inertial measuring unit (9), and a correction value for the position correction of the track (5) is derived from the calibration with the actual geometry (I).

9. The method of claim 8, wherein, Unfiltered measurement data of the measured track section (26) from the inertial measuring unit (9) are transmitted to the evaluation device (40), a virtual inertial measurement of the same track section (26) with the target geometry (S) is simulated by means of a simulation device in order to obtain simulated measurement data in the case of the target geometry (S), and the simulated measurement data are subtracted from the unfiltered measurement data of the inertial measuring unit (9) in order to derive a correction value for the position correction of the track (5).

10. The method of claim 1, wherein, At least one measured actual position point (15) is determined as a constraint point (24) for the compensation calculation (35), which at least one measured actual position point does not lie between the start point (28) and the end point (29) of a construction section (27) provided for the position correction.

11. System for carrying out a method according to one of claims 1 to 10, the system having a measuring locomotive (1) for driving over a track section (26), the measuring locomotive (1) comprising a measuring system (8) for measuring an actual geometry (I) of the track (5), and the system further having a computing unit (36) for calculating a target geometry (S) on the basis of the actual geometry (I), characterized in that The measuring locomotive (1) comprises a position detection system (12) for detecting a plurality of actual position points (15) along a track section (26), a presetting device (23) for the computing unit (36) is provided for presetting at least one actual position point (15) as a constraint point (24), and an algorithm is configured in the computing unit (36) which corresponds the nominal geometry (S) as a sequence of geometric track elements (31, 32, 33) to the actual geometry (I) and the nominal geometry (S) is routed through at least one constraint point (24).

12. The system of claim 11, wherein, The measuring locomotive (1) has a sensor device (17) for automatically recognizing fixed track points (18, 19) at their location, and the sensor device (17) is coupled to the presetting device (23) in order to determine the actual position points (15) associated with the track points (18, 19) as constraint points (24).

13. The system of claim 11, wherein, The presetting device (23) comprises an operating unit (25) by means of which an actual position point (15) can be determined as a constraint point (24) by an operator.

14. The system of claim 11, wherein, The position detection system (12) comprises a GNSS receiving device.

15. The system of claim 14, wherein, The GNSS receiving device is coupled to a position measuring device (7) in order to determine the position of the GNSS receiving device relative to the track (5).

16. The system of claim 11, wherein, The measuring system (8) comprises an inertial measuring unit (9).

17. The system of claim 16, wherein, The measuring system (8) comprises a position measuring device (7) for determining the position of the inertial measuring unit (9) relative to the track (5).

18. The system of claim 11, wherein, For the position correction of the track (5) there is an evaluation device (40) for calculating correction values, and there is a control device of a track superstructure machine for processing the correction values, in order to bring the track into a preset nominal geometry by means of a controlled lifting calibration device. The measuring locomotive (1) comprises a position detection system (12) for detecting a plurality of actual position points (15) along a track section (26), a presetting device (23) for the computing unit (36) is provided for presetting at least one actual position point (15) as a constraint point (24), and an algorithm is configured in the computing unit (36) which corresponds the nominal geometry (S) as a sequence of geometric track elements (31, 32, 33) to the actual geometry (I) and the nominal geometry (S) is routed through at least one constraint point (24). The measuring locomotive (1) has a sensor device (17) for automatically recognizing fixed track points (18, 19) at their location, and the sensor device (17) is coupled to the presetting device (23) in order to determine the actual position points (15) associated with the track points (18, 19) as constraint points (24). The presetting device (23) comprises an operating unit (25) by means of which an actual position point (15) can be determined as a constraint point (24) by an operator. The position detection system (12) comprises a GNSS receiving device. The GNSS receiving device is coupled to a position measuring device (7) in order to determine the position of the GNSS receiving device relative to the track (5). The measuring system (8) comprises an inertial measuring unit (9). The measuring system (8) comprises a position measuring device (7) for determining the position of the inertial measuring unit (9) relative to the track (5). For the position correction of the track (5) there is an evaluation device (40) for calculating correction values, and there is a control device of a track superstructure machine for processing the correction values, in order to bring the track into a preset nominal geometry by means of a controlled lifting calibration device.

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