METHOD AND SYSTEM FOR DETERMINING A TARGET PROFILE OF THE TRACK TO CORRECT THE GEOMETRY

Abstract

A method for determining a target geometry of a track for correcting the geometry of the track. An actual geometry of the track is detected first on a track section by a measuring system and the target geometry is calculated on the basis of the actual track geometry afterwards by way of a computing unit. Actual position points of the track are detected along the track section by a position detection system, with at least one actual position point being given to the computing unit as a point of restraint, and with the target geometry being calculated by the computing unit such that the target geometry is adapted to the actual geometry as a sequence of geometric track alignment design elements and is placed through the preset point of restraint. The method achieves a significant increase in quality compared to the known compensation method using pre-measurement.

Claims

1-15. (canceled)

16. A method for determining a target geometry of a track to correct a geometry of the track, the method comprising: detecting an actual geometry of the track on a track section by a measuring system; detecting actual position points of the track along the track section by a position detection system and transmitting at least one actual position point to a computing unit as a preset point of restraint; calculating the target geometry on a basis of the actual geometry by the computing unit, and thereby calculating the target geometry in such a way that the target geometry is adapted to the actual geometry as a sequence of geometric track alignment design elements and is placed through the preset point of restraint.

17. The method according to claim 16, which comprises automatically detecting a track point that is fixed in its position by way of a sensor device and setting the actual position point associated with a detected fixed track point as the point of restraint by a presetting device.

18. The method according to claim 16, which comprises presetting an actual position point as a point of restraint by an operator by way of a presetting device.

19. The method according to claim 16, which comprises detecting the actual position points as Global Navigation Satellite System coordinates by way of a GNSS receiving device.

20. The method according to claim 19, which comprises detecting the actual position points by a differential GNSS system.

21. The method according to claim 16, which comprises detecting the actual geometry of the track by way of an inertial measuring unit.

22. The method according to claim 21, which comprises providing a time stamp as a common time base for each measuring datum by the inertial measuring unit.

23. The method according to claim 21, which comprises determining a three-dimensional trajectory from measuring data of the inertial measuring unit in an evaluation device, and determining correction values from a comparison with the target geometry to correct the geometry of the track.

24. The method according to claim 21, which comprises outputting unfiltered measuring data of the detected track section by the inertial measuring unit to an evaluation device, and simulating a virtual inertial measurement of the same track section with the target geometry by a simulation device in order to obtain simulated measuring data assuming the target geometry, and determining correction values for correcting the geometry of the track by subtracting the simulated measuring data from the unfiltered measuring data of the inertial measuring unit.

25. The method according to claim 16, which comprises determining at least one detected actual position point which does not lie between a starting point and an end point of a worksite section intended for position correction as a point of restraint for the compensation calculation.

26. A system for implementing the method according to claim 16, the system comprising: a track inspection vehicle for travelling on a track section, the vehicle including a measuring system for detecting an actual geometry of the track and a position detection system for detecting actual position points along the track section; a computing unit for calculating a target geometry on a basis of the actual geometry of the track; a presetting device for said computing unit, for determining at least one actual position point as a point of restraint; said computing unit being configured to process an algorithm for adapting the target geometry to the actual geometry as a sequence of geometric track alignment design elements and for placing the target geometry through the at least one point of restraint.

27. The system according to claim 26, wherein said track inspection vehicle comprises a sensor device for an automated detection of a track point that is in a fixed position, said sensor device being coupled to said presetting device in order to define an actual position point associated with said track point as a point of restraint.

28. The system according to claim 26, wherein said presetting device comprises an operating unit configured to enable an operator to determine an actual position point as a point of restraint.

29. The system according to claim 26, wherein said position detection system comprises a Global Navigation Satellite System receiving device, which is coupled to position measuring devices for determining the position of said GNSS receiving device relative to the track.

30. The system according to claim 26, wherein said measuring system comprises an inertial measuring unit and position measuring devices for determining a position of said inertial measuring unit relative to the track.

31. The system according to claim 26, further comprising an evaluation device configured to calculate correction values for correcting the geometry of the track, and a control device of a track maintenance machine configured to process the correction values in order to place the track into the preset target geometry by way of a controlled lifting and lining unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In the following, the invention is explained by way of example with reference to the accompanying figures. The following figures show in schematic illustrations:

[0034] FIG. 1 Track inspection vehicle on a track

[0035] FIG. 2 Location diagram with worksite section and measurement section

[0036] FIG. 3 Block diagram for determining correction values

[0037] FIG. 4 Diagrams of a track course

[0038] FIG. 5 Diagrams of a curved track with transition curves and straight lines

[0039] FIG. 6 Location diagram of a track section with actual geometry and target geometry

DESCRIPTION OF THE EMBODIMENTS

[0040] FIG. 1 shows a track inspection vehicle 1 with a vehicle frame 2 on which a railway vehicle body 3 is mounted. The track inspection vehicle 1 is movable on a track 5 by means of rail-based running gears 4. For better illustration, the vehicle frame 2 together with the railway vehicle body 3 is shown in a raised position from the rail-based running gears 4. The track inspection vehicle 1 can also be designed as a track maintenance machine, in particular as a tamping machine. In this case, only one machine is required to survey and correct the track 5.

[0041] The rail-based running gears 4 are preferably designed as bogies. A measuring frame 6 is connected to the wheel axles of the bogie so that any movement of the wheels is transmitted to the measuring frame 6 without spring action. Thus, there is only lateral or reciprocal movement of the measuring frame 6 in relation to the track 5. These movements are detected by means of position measuring devices 7 arranged on the measuring frame 6. They are designed, for example, as light section sensors.

[0042] The position measuring devices 7 are components of a measuring system 8 mounted on the measuring frame 6, which comprises an inertial measuring unit 9. Measuring data of a trajectory 10 are recorded with the inertial measuring unit 9 during a measuring run, with relative movements of the inertial measuring unit 9 in relation to the track 5 being compensated for by means of the data from the position measuring devices 7. This way, the detection of an actual geometry I of the track 5 is achieved. By means of the measuring data of the position measuring devices 7, the measuring data of the inertial measuring unit 9 can also be transformed to a respective rail 11 of the track 5. The result is a trajectory 10 for each rail 11.

[0043] The track inspection vehicle 1 further comprises a position detection system 12, by means of which a current position of the track inspection vehicle 1 can be detected. Due to the known position of the track inspection vehicle 1 in relation to the track 5, the position of the currently travelled track point can also be detected. For example, the position detection system 12 comprises a GNSS receiving device that is rigidly connected to the vehicle frame 2 via a carrier 13. The GNSS receiving device comprises several GNSS antennas 14 arranged in relation to each other for an accurate detection of GNSS positions of the track inspection vehicle 1. In order to record the reciprocal movements of the vehicle frame 2 in relation to the track 5, further position measuring devices 7 are arranged on the vehicle frame 2. Again in this case, light section sensors are used. For a simple embodiment of the invention, one GNSS antenna 14 is sufficient. This way, actual position points 15 of the track 5 or a common centre-line of the track 16 are continuously detected.

[0044] An alternative position detection system 12 not shown comprises a radio-based measuring system for real-time localisation. In this system, several transmitter modules are attached to the track inspection vehicle 1. Reference stations located next to the track line include transponders. By means of a continuous distance measurement between the transmitter modules and the transponders, the position of the track inspection vehicle 1 and thus the position of the track point currently being travelled on can be determined in relation to the reference stations. The reference stations are only used to determine the position without reference to the original design geometry of the track 5.

[0045] In addition, the track inspection vehicle 1 comprises a sensor device 17 for automatically detecting a track point 18, 19 that is structurally fixed in its position (FIG. 2). Advantageously, the sensor device 17 comprises several sensors 20, 21, 22, the data of which is evaluated together. For example, a video camera 20, a rotating laser scanner 21 and an infrared camera with infrared lighting 22 are used. The sensor device 17 is coupled to a presetting device 23 in order to set an actual position point 15 associated with a fixed track point 18, 19 as a point of restraint 24. As an alternative to the sensor device 17 or in addition to it, the presetting device 23 may comprise an operating unit 25. An actual position point 15 can be preset by an operator as a point of restraint 24 by means of this operating unit 25.

[0046] FIG. 2 shows a track 5 that is travelled on by the track inspection vehicle 1. A dash-dotted outline indicates the length of a track section 26 on which the actual geometry I and the actual position points 15 of the track 5 are detected. A dashed outline indicates the length of a worksite section 27 on which the track 5 will be corrected later. The worksite section 27 is shorter than the measured track section 26 and is bounded by a starting point 28 and an end point 29.

[0047] On the track section 26 shown, there are two track points 18, 19, which are structurally fixed in their position. These are, for example, a level crossing 18 with rigid pavement and a bridge 19 without ballast bedding. The bridge 19 is located outside of the worksite section 27. During a measuring run, actual position points 15 assigned to these track points 18, 19 are determined as points of restraint 24.

[0048] In the example shown, a stationary coordinate system XYZ is used for georeferencing the measuring results, the origin of which is at the starting point of the measuring run. The X-axis points north, the Y-axis points east, and the Z-axis points downwards. During the measuring run, a distance s is further recorded which can be used, in addition to a time stamp, to synchronise the measuring results of the different systems 8, 12, 17.

[0049] Track main points 30 are located along the track section 26. These track main points 30 each mark a boundary between a straight line 31 and a transition curve 32 as well as between a transition curve 32 and a circular curve 33. A straight line 31, a transition curve 32, and a circular curve 33 (full curve) are defined as geometric track alignment design elements.

[0050] The block diagram in FIG. 3 illustrates the individual steps of the method. First, a pre-measurement 34 is carried out to detect the relative actual geometry I and the GNSS position P of the track 5. The measuring data of the inertial measuring unit 9 and coordinate data for the detected actual position points 15 are available as results.

[0051] Subsequently, a compensation calculation 35 is carried out by means of an optimisation algorithm which is set up in a computing unit 36. Specifically, a track-geometry optimisation 37 is performed by forming a track geometry based on the actual geometry I by lining up geometric track alignment design elements 31, 32, 33 to remove track geometry faults. This optimisation process 37 takes place in dependence on a track-position optimisation 38, by lining up and dimensioning track alignment design elements 31, 32, 33 in such a way that the resulting target geometry S of the track 5 is placed through predetermined points of restraint 24.

[0052] Boundary conditions for these optimisation processes 37, 38 are formed by the connection points at the borders of the worksite section 27. Specifically, the target geometry S must be placed through the starting point 28 and through the end point 29 of the worksite. Furthermore, the target geometry S must be tangential to the unworked track 5 at these points 28, 29. For example, an optimisation algorithm is used which optimises the deviations between the target geometry S and the actual geometry I as an objective function under the existing constraints (method of least squares).

[0053] With the target geometry S preset in this way, a correction-value calculation 39 is carried out in the next step. In a first variant, this is done by means of the three-dimensional trajectory 10, which is derived from the measuring data of the inertial measuring unit 9. The actual geometry I of the track 5 is directly derived from the coordinates of the trajectory 10, so that the correction values can be directly determined from a comparison with the target geometry S. These are usually displacement values (lining values) and lifting values for lateral lining and for lifting the track panel. Preferably, individual lifting values are preset for each rail 11, for example to compensate for individual faults or to adjust superelevations. The correction values are determined by means of an evaluation device 40, which is supplied with the values of the actual geometry I and the target geometry S of the track 5.

[0054] In a second variant, the unfiltered measuring data of the inertial measuring unit 9 are used. This eliminates the need to identify the coordinates of the trajectory 10 for the correction-value calculation 39. Instead, an evaluation device 38 carries out a simulation, in which an inertial measurement is simulated. Based on the real measurement of the track section 26 by means of the real inertial measuring unit 9, a virtual measurement of the same track section 26 with the calculated target geometry S is carried out. For this, a virtual inertial measuring unit is used. The real and the virtual measuring unit use the same inertial measuring method. Method-related artefacts occur in both the real and the virtual measurement. By subtracting the obtained measuring data of the actual geometry I and the target geometry S, these artefacts cancel each other out. As a result, the correction values for the corresponding track section 26 are obtained.

[0055] The correction values are provided to a control device of a lifting and lining unit of a tamping machine. The tamping machine can simultaneously be designed as the track inspection vehicle 1 described herein. To correct the track geometry, the track 5 is travelled on by the tamping machine after pre-measurement. According to the preset correction values, the track panel is placed to its desired position by means of the lifting and lining unit and is fixed in place by means of a tamping unit. A chord-based measuring system mounted on the tamping machine is used to check the track geometry. Advantageously, a so-called track geometry guiding computer (also called ALC, automatic guiding computer) in the tamping machine comprises the computing unit 36 and the evaluation device 40. The guiding computer serves as the central unit for determining the correction values and for controlling the tamping machine.

[0056] FIG. 4 shows a curvature diagram (curvature illustration) and a superelevation diagram (superelevation illustration) in the upper two diagrams. The distance s is plotted on the abscissa. The ordinate of the curvature diagram shows the current curvature or alignment r above the distance s. The ordinate of the superelevation diagram shows the superelevation or level h above the distance s.

[0057] In the illustration below, the associated location diagram of the track section 26 is shown in a stationary coordinate system XYZ with the X coordinates and Y coordinates. The track section shown begins with a straight line 31 and then changes into a transition curve 32 with increasing curvature until the curvature remains constant in the subsequent circular curve 33 (full curve).

[0058] In the diagrams and in the location diagram, the measured actual geometry I is shown with dashed lines. It is clearly visible that there is no unambiguous position of the track main points 30 for the target geometry S to be determined. Two variants are shown which lead to transition curves 32 of different lengths and thus to different target geometries S. The method according to the invention uses this flexibility to achieve an optimised sequence of the geometric track alignment design elements.

[0059] FIG. 5 also shows a curvature diagram, a superelevation diagram, and a location diagram. The solid lines respectively show the target geometry S, which was determined using the method according to the invention. Here, an actual position point 15, which is assigned to a fixed track point 19 (e.g. bridge), is preset as a point of restraint 24. Based on the determined actual geometry I and the preset point of restraint 24, the target geometry S is adapted as a sequence of geometric track alignment design elements of the actual geometry I in such a way that the point of restraint 24 lies on the line of the target geometry S. This results in the correct position for the marked track main points 30. In the location diagram, two examples are marked with dotted lines, which show a possible target geometry according to the conventional compensation method. The track main points 30 deviate from the correct position within a fault range 41 shown in a hatched pattern. Even small mistakes can have a big impact on the resulting location diagram.

[0060] With reference to FIG. 6, it is explained that a point of restraint 24 preset outside the worksite also positively influences the target geometry S in the worksite section 27. A location diagram of a track section 26 is shown on which a pre-measurement was carried out by means of the track inspection vehicle 1. The detected actual geometry I is shown with a thin solid line. A dotted line shows a possible target geometry according to the conventional compensation method. In this, the actual geometry I is merely smoothed. It is clearly visible that the marked point of restraint 24 is missed at a fixed track point 18 (e.g. level crossing).

[0061] In the method according to the invention, the coordinates of the point of restraint 24 are included in the calculation of the target geometry S. This results in the sequence of geometric track alignment design elements marked with a solid line. Again, track main points 30 indicate the boundaries of the track alignment design elements. In the example shown, the track 5 corrected according to the conventional compensation method would connect to the unworked track with a transition curve 32.

[0062] In the method according to the invention, the track 5 continues as a longer straight line 31 at this point due to the included point of restraint 24. Connection angle and position coordinates of the track 5 in the end point 29 of the worksite remain the same. This ensures that an optimal result is achieved in the event of a later correction of the further course of the track. In FIG. 6, the courses of track 5 are strongly exaggerated to illustrate the effect described.