EP3802956B1 - Method for tamping a track in the region of a railway switch - Google Patents

Description

field of technology

The invention relates to a method for tamping a track in the area of a set of points using a tamping machine that can be moved along the track, in which a first branch is brought into a desired position and tamped in a first work cycle, with the tamping machine then moving backwards to a branch point and in a second A second branch is brought into a target position and stuffed during the work cycle.

State of the art

Track-movable tamping machines for tamping track sections and switch sections have been known for a long time. For example, the EP 1 143 069 A1 such a machine. This includes a lifting/straightening unit for leveling and straightening a main track (main track) and an additional lifting device for lifting a branch track branching off from the main track (branch line of a switch). In the first work step, the branch track is also lifted in the effective range of the additional lifting device while driving on the main track, with a common measuring system ensuring a controlled lifting of the points.

In this way, the actual position of the branch track is changed in the area of the switch and any measurement previously carried out can no longer be used to provide specifications for raising or straightening and tamping the continuing branch track. According to the state of the art, a manual measurement of the result of the first work pass must therefore be carried out before a second work pass, in which the branch track is driven on and tamped.

Summary of the Invention

The invention is based on the object of specifying improvements over the prior art for a method of the type mentioned at the outset.

According to the invention, this object is achieved by the combination of features of independent claim 1. Advantageous developments of the invention result from the dependent claims.

During reversing, an actual position of the second branch is detected by means of a sensor arrangement, in particular in relation to the position of the first branch, and correction values for the position of the second branch are calculated on the basis of this detected actual position. The reverse travel, which is necessary in any case, is used in this way to determine the position of the second branch that has changed during the course of the first work pass. This eliminates the need for a time-consuming manual intermediate measurement before the second work cycle can begin. The first branch here is the track that is lifted and straightened during the first work pass, regardless of whether it is a main track or a branch track.

Advantageously, the actual position of the second branch is detected in a detection area that extends beyond a switch end. The end of the switch is usually the last continuous common sleeper of the main track and branch track. Thus, while reversing, the entire area is covered in which the second branch has a new position after the first work pass.

A further improvement provides that a reference plane defined by the position of the first branch is specified and that correction values for the position of the second branch are calculated as deviations from this reference plane. In this way, the correction of the second branch, carried out in the second pass, is carried out in relation to the first branch, which has already been stuffed. As an alternative to this, the correction of the second branch can also take place with respect to another predetermined desired position.

To detect the actual position, surface contours of the two branches are advantageously detected by means of the sensor arrangement. Using the surface contours of the rails in particular, the actual positions of the track axes can be calculated in a simple manner and the correction values can then be specified.

It is favorable here if the surface contours are recorded as a cloud of points and evaluated by means of a computing unit. Efficient algorithms are known for processing the corresponding data, which enable the track axes to be determined quickly and precisely. Filter methods can also be used to reduce the amount of data. For example, only the surface points of the rails are processed further. With known algorithms, imaging errors, distortion errors or other detection errors are also reliably detected and eliminated.

A development of the method provides that the calculated correction values are transmitted to a so-called control computer of the tamping machine. The control computer is a computing unit for carrying out a track geometry correction, with the tamping machine being guided according to a specified target geometry of the track. The control computer specifies the appropriate parameters for the control devices of the tamping machine.

Brief description of the drawings

Fig. 1

Stopfmaschine in einer Seitenansicht

Fig. 2

Weichenabschnitt in einer Aufsicht

Fig. 3

Querschnitt eines Stammgleises und eines Zweiggleises

The invention is explained below in an exemplary manner with reference to the accompanying figures. They show in a schematic representation:

1

Tamping machine in a side view

2

Switch section in a top view

3

Cross-section of a main track and a branch track

Description of the embodiments

In the 1 The tamping machine 1 shown can be moved on a track 3 by means of driven rail carriages 2 . Track 3 includes Sleepers 4, which form a track grid with rails 5 fastened to them, which is mounted in a ballast bed 6. A switch 7 branches the track 3 into two branches 8,9. In the case of a simple switch according to 2 are these a main track and a branch track. In addition, a distinction is made between curved points, double points and crossing points. Special procedures and special tamping machines are used to correct the position of such switch sections.

To carry out a track position correction, the tamping machine 1 comprises a tamping unit 10, a lifting device 11 and a measuring device 12 with measuring carriages 13 and measuring chords 14. The measuring chords 14 are, for example, tensioned steel chords or optical chords that run between light-emitting elements and light sensors. In addition to a main lifting adjustment device 15, the lifting adjustment device 11 has two laterally extendable additional lifting adjustment devices 16. A branching branch 9 is lifted and straightened by means of the respective additional lifting reporting device 16 until a maximum lateral processing limit 17 is reached.

A sensor arrangement 19 is attached to the front face in the working direction 18 . This includes a laser scanner 20 and/or a light section sensor 21 and an evaluation device 22 for calculating a point cloud. Further information can be recorded by means of a camera 23 . For example, the point cloud can be supplemented with color information.

A switch section to be processed with a simple switch 7 comprises a switch heart 24, switch tongues 25 and check rails 26 as well as a switch start 27 and two switch ends 28. The main track and the branch track have continuous sleepers 4 up to the switch ends 28, so that lifting or straightening of one branch inevitably affects the other branch.

When correcting the track position in the switch section, the first branch 8 is initially brought into a predetermined target position in a first work step. The elevation reporting device 11 lifts and aligns the track grid, with the current track position being measured continuously by means of the measuring device 12 is recorded and compared with the specified target position. When the target position is reached, the track grid is stabilized in its position by compacting the ballast bed 6 by means of the tamping unit 10 .

The tamping machine 1 is guided with a so-called master computer 29 according to a known desired geometry of the track 3. As an alternative to this, there is also the possibility of guiding the tamping machine 1 with an unknown target geometry. For this purpose, a measuring run is carried out with the tamping machine 1 before the track position is corrected, and the target position is determined with corresponding correction values from the measured actual position of the track 3 by means of an electronic versine correction.

According to the invention, the sensor arrangement 19 is set up in such a way that the actual position of the second branch 9 is detected while the tamping machine 1 is reversing up to a junction point. Since the tamping machine 1 moves along the first branch 8, this forms the reference basis for detecting the actual position of the second branch 9. Correction values 30, 31, 32 for the position of the second branch 9 are calculated from this. The position of the second branch 9 is detected in a detection area 33 in which the actual position of the second branch 9 was changed during the first work cycle. This detection area 33 extends at least beyond the processing limit 17 and advantageously beyond the switch end 28 . The larger detection area 33 allows reliable detection of the entire section of the second branch 9 that was changed during the first work pass.

Advantageously, the laser scanner 20 is arranged on the front face of the tamping machine 1 in the middle in the upper area, so that a wide area is covered on both sides of the tamping machine 1 . A laser beam rotating about a longitudinal axis of the tamping machine 1 sweeps over the surface of the track 3 and its surroundings, a distance to the irradiated surface point being measured at clocked intervals. In this way, a grid-like detection of the surface is created. Specifically, with each revolution of the laser beam, a cross-section of the track and its surroundings is measured, with a helical juxtaposition of measuring points takes place. The sum of all measuring points provides a point cloud of the track and its surroundings.

As an alternative to this or in addition to this, light section sensors 21 are arranged above each rail. These also emit laser beams and measure the distance to an illuminated surface point using a detector based on the principle of triangulation. Here, too, the result is a point cloud of the track and its surroundings. With the simultaneous use of several sensors 20, 21, 23, sensor fusion brings together all the measurement data by means of the evaluation device 22. The resulting point cloud contains precise position information and possibly color information of the surface points of track 3 and its surroundings.

An orthogonal coordinate system x, y, z following the course of the track is advantageously specified as a common reference system ( 3 ). The origin of the coordinates is preferably on the so-called track axis 34 (center of the track), which runs at half the track width between the two rails 5 . The x-axis of the coordinate system points in the direction of travel, the y-axis in the transverse direction of the track. The z-axis values then indicate height deviations of the detected surface points with respect to the xy plane.

In addition to detecting the position with respect to the coordinate system, the distance s to a reference point fixed along the track is continuously recorded (kilometre counting), for example by means of an odometer. Alternatively or in addition, a GNSS device can be used to determine the current measurement position. The y-coordinates and z-coordinates relevant to the track position are thus assigned to an exact position on track 3. The same applies when specifying a stationary or inertial coordinate system as a common reference system.

The detected point cloud is usually initially related to a different coordinate system, which is moved with the sensor device 19, for example. For a coordinate transformation, the position of the track axis 34 is first calculated from coordinates of the surface points 35 on the inner edges of the rails 5 of the track 3 traveled on. This Surface points 35 are determined using known pattern recognition methods. Subsequently, the coordinates of all points or a previously filtered point set of the point cloud are transformed to the x, y, z coordinate system following the course of the track. The transformation process preferably takes place in a computing unit 36 of the tamping machine 1, in which software for pattern recognition and coordinate transformation is set up.

In this way, the surface points of the second branch 9 in relation to the first branch 8 are recorded during the reverse movement of the tamping machine 1 after the first work pass has taken place. In a next method step, the software set up in the computing unit 36 determines the coordinates of the surface points 35 on the inner edges of the rails 5 of the second branch 9 and the corresponding track axis 34. This is done by means of pattern recognition and, if necessary, by interpolation if no recorded surface point can be assigned to the respective inner rail edge is.

Based on this data, the reach unit 36 calculates correction values 30, 31, 32 for the two rails 5 or the track axis 34 for the second work cycle, depending on the distance s along the second branch 9. Specifically, all relevant points of the point cloud along the two branches 8, 9 for the calculation of the correction values 30, 31, 32 used. It is irrelevant that during the measurement by means of the laser scanner 20 a transverse profile of the track 3 recorded on the first branch 8 results in a profile of the track 3 running obliquely for the second branch 9 . As soon as all the scanned surface profiles have been put together to form the spatial point cloud, the entire actual geometry of the two detected branches 8, 9 is known in a common reference system.

The second branch 9 is usually raised to the level of the first branch 8 that has already been processed. The correction values are easy to determine because the first branch is specified as the reference system for capturing the point cloud. In the simplest case, a reference plane 37 predetermined by the position of the first branch 8 is determined and deviations from this plane are used as correction values 30, 31, 32 Reference plane 37 calculated. In other words, the correction values 30, 31, 32 correspond to the detected deviations in the direction of the z-axis. If the specified target position of the first branch 8 was not reached in the first work run, this target position that was not reached is used as the reference system for the calculation of the correction values 30 , 31 , 32 . There is therefore no error propagation.

If, in exceptional cases, the second branch 9 has its own longitudinal gradients, the correction values 30, 31, 32 are calculated accordingly Correction work continued as usual. This transition can be recognized by the fact that the actual position of the second branch 9 recorded during reversing corresponds to a previously measured actual position at the corresponding track location.

After the correction values 30 , 31 , 32 have been transferred to the control computer 29 , the control computer 29 calculates the working and adjustment parameters that are required to control the tamping machine 1 . As an alternative to this, the actual position of the second line 9 can be transmitted to the control computer 29, in particular as a course of arrow heights. The correction values 30, 31, 32 are then calculated by means of the control computer 29 by comparison with a stored target position of the corresponding track section. During the work passes, the measuring device 12 is used to ensure that the specified corrections are achieved.

Claims (6)

1. A method of tamping a track (3) in the area of a switch (7) by means of a tamping machine (1) mobile on a track, wherein in a first working pass a first branch (8) is brought into a target position and tamped, wherein subsequently the tamping machine travels rearward to a location ahead of a branch-off point, and wherein in a second working pass a second branch (9) is brought into a target position and tamped, characterized in that, during the rearward travel, an actual position of the second branch (9) is recorded by means of a sensor arrangement (19), in particular with respect to the position of the first branch (8), and that - based on this recorded actual position - correction values (30, 31, 32) for the position of the second branch (9) are calculated.
2. A method according to claim 1, characterized in that the recording of the actual position of the second branch (9) takes place in a recording area (33) extending beyond a switch end point (28).
3. A method according to claim 1 or 2, characterized in that a reference plane (37) defined by the position of the first branch (8) is specified, and that correction values (30, 31, 32) for the position of the second branch (9) are calculated as deviations with regard to said reference plane (37).
4. A method according to one of claims 1 to 3, characterized in that surface contours of the two branches (8, 9) are recorded by means of the sensor arrangement (19).
5. A method according to claim 4, characterized in that the surface contours are recorded as a point cloud and evaluated by means of a computer unit (36).
6. A method according to one of claims 1 to 5, characterized in that the calculated correction values (30, 31, 32) are transmitted to a so-called guiding computer (29) of the tamping machine (1).

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