EP3870757A1

EP3870757A1 - Track construction machine and method for tamping sleepers of a track

Info

Publication number: EP3870757A1
Application number: EP19778908.4A
Authority: EP
Inventors: Thomas Philipp; Reinhard BÖCK
Original assignee: Plasser und Theurer Export Von Bahnbaumaschinen GmbH
Current assignee: Plasser und Theurer Export Von Bahnbaumaschinen GmbH
Priority date: 2018-10-24
Filing date: 2019-09-23
Publication date: 2021-09-01
Anticipated expiration: 2039-09-23
Also published as: AT521850A1; EA202100085A1; JP2022505726A; EP3870757C0; PL3870757T3; US20220056647A1; AU2019363551A1; CA3111338A1; EP3870757B1; JP7389115B2; WO2020083584A1; CN112789379A

Abstract

The invention relates to a track construction machine comprising a tamping assembly (1) for tamping sleepers (7) of a track (5) lying in a ballast bed (6), said tamping assembly (1) comprising a tool carrier (8) height-adjustably mounted on an assembly frame (2), on which tool carrier tamping tools (15) are arranged such that they can be moved towards each other, wherein the tool carrier (8) is coupled to a height adjustment drive (10) controlled by means of a control device (16). In order to control a lowering movement (9) of the tool carrier (8), a control circuit is configured with a controller (18), an adjusting device (19) for the height adjustment drive (10), and a measuring device (20) for detecting the lowering movement (9).

Description

description

Track construction machine and method for stuffing sleepers of a track

Technical field

The invention relates to a track construction machine with a tamping unit for tamping sleepers of a track lying in a ballast bed, comprising a height-adjustable tool carrier mounted on an aggregate frame, on which tamping tools can be provided to one another, the tool carrier being connected to one another by means of a

Control device controlled height adjustment drive is coupled. In addition, the invention relates to a method for operating a

corresponding track construction machine.

State of the art

A track construction machine equipped with a tamping unit is used to produce or stabilize a desired track position. The track construction machine travels the track and lifts the track grate, which is formed from sleepers and rails, to a target level using a lifting / straightening unit. The new track position is fixed by tamping the sleepers with the tamping unit. For this purpose, tamping tools (tamping picks) are set in vibration, lowered into the ballast bed on both sides of a sleeper and added to each other in order to compact the ballast under the sleeper. The tamping tools are then lifted out of the ballast bed and moved apart. The

The tamping unit is positioned over the next threshold and a new tamping cycle begins.

[03] There are various for lowering and lifting the tamping tools

Known solutions. For example, EP 1 233 108 A1 describes a lifting and lowering mechanism for a tamping unit, in which a hydraulic cylinder and a lever arrangement are coupled to an assembly frame. A tamping unit with several tool carriers is known from EP 0 698 687 A1 known. Each tool holder is assigned its own height adjustment drive for separate lowering and lifting.

[04] For a specification of the lowering movement, an operator usually has up to three speed levels to choose from in order to achieve the

Consider the nature of the ballast bed. At a

Lowering the track usually takes place at a lower rate

Speed than with a ballast bed hardened by wear and environmental influences. The goal is to quickly reach a specified immersion depth with a constant lowering time. A corresponding specification is made by manual setting and is based on the experience of the operator.

[05] AT 519 195 A1 discloses a tamping unit in which a vertical vibration is superimposed on the lowering movement of the tamping tools in order to facilitate penetration of the tamping tools into a hardened ballast bed. However, an additional load on the track construction machine is accepted because the vertical vibration also affects you

Transfers machine frame to which the tamping unit is attached.

Summary of the invention

[06] The invention is based on the object of a track construction machine

to further develop the type mentioned above so that the tamping tools of the tamping unit can be lowered into a ballast bed in an optimized manner. In addition, a correspondingly optimized method for operating the track construction machine is to be specified.

[07] According to the invention, these objects are achieved by the features of

Claims 1 and 6. Advantageous further developments of the invention result from the dependent claims.

[08] The invention provides that to regulate a lowering movement of the

Tool holder a control loop with a controller, an adjusting device for the height adjustment drive and a measuring device for detecting the lowering movement is set up. It is possible for that

Lowering movement to provide an optimal sequence. This applies to acceleration as well as the rate of penetration upon impact the tamping pick on the ballast bed as well as a braking process at

Reaching the immersion depth. With the control, individual phases of the lowering movement can be coordinated with one another, so that overall there is a minimal lowering time while protecting the track-laying machine and the ballast bed.

[09] The measuring device advantageously includes a position transmitter for detecting a height position of the tool holder. A corresponding control variable of the control loop can be predefined in a simple manner and leads to stable control. Alternatively or additionally, a

Speed or an acceleration of the tool carrier or the tamping tools are detected.

[10] It is also advantageous if the controller is preceded by a pilot control or a pre-filter for adapting a reference variable of the control loop. The pilot control or the pre-filter uses a mathematical model with setting parameters for an optimized

Control of the actuating device in order to follow a predetermined sequence of the lowering movement with minimized deviations.

[11] In an advantageous embodiment of the invention, the

Height adjustment drive a hydraulic cylinder with a hydraulic valve as an adjusting device. Hydraulic cylinder and hydraulic valve allow optimal control of the lowering movement and the lifting movement with short

Cycle times and provision of high forces.

The hydraulic valve is advantageously designed as a pilot-controlled control valve. A highly dynamic and high-precision drive of a pilot valve enables optimal control of the main stage with a sufficiently high flow capacity. As an alternative, a servo valve or a proportional valve can be used.

[13] In the method according to the invention for stuffing in one

Ballast bed sleepers of a track with one above

described track construction machine, the tamping unit is positioned over a tamping point of the track and the tool carrier via the height adjustment drive with tamping tools penetrating into the ballast bed lowered, the lowering movement being carried out with a regulated movement quantity.

[14] To deviate control deviations in the regulation of the lowering movement

it is advantageous to minimize a reference variable by means of a precontrol upstream of the controller or by means of a pre-filter upstream of the controller.

[15] An advantageous further development of this method provides that a

Control difference occurring during a stuffing cycle is fed to a computing unit and that based on the control difference in the

Computing unit is adapted by means of an iterative learning control algorithm at least one parameter of the pre-control or the pre-filter. This automatically reacts to changes in the state of the ballast bed, minimizing the control interventions for subsequent tamping cycles.

[16] The lowering movement of the tool carrier is favorably by means of

of a position encoder. This is either arranged on the tamping unit or at another location on the track construction machine, from which contactless detection of the lowering movement is possible.

[17] For stable control, it is advantageous if the control loop is given a reference variable that is dependent on a lowering time. As

A predefined sequence of a lowering movement can then generate a function over time.

[18] It makes sense if the control loop has a lowering path above the

Lowering time is specified as a reference variable. In a corresponding time-distance curve, a desired braking curve and the

intended immersion depth can be specified.

[19] In an advantageous development, a setpoint curve is generated by means of a

Setpoint generator specified. This makes it possible to automatically specify the reference variable. For example, in the setpoint generator

Different setpoint curves are stored and a selection is made using an intelligent control system, assuming one or more parameters. The specification of parameters or a setpoint curve by an operator can also be useful. [20] It is also advantageous if this is used as a setpoint generator

trained setpoint generator a feedback variable of the control loop is supplied, the predetermined lowering movement is adjusted depending on the feedback variable. The feedback variable is the measured control variable and allows conclusions to be drawn about the nature of the ballast bed. For example, a highly compacted ballast bed can result in a predetermined immersion depth no longer being achieved despite the regulation. The setpoint generator then gives the control loop one

Lowering movement with higher immersion speed. In this way, the available adjustment range of the actuating device is always optimally used.

An improved method also provides that at least one of the im

Control loop processed quantities is supplied to an evaluation device and that a characteristic variable for the ballast bed is derived from the at least one size by means of the evaluation device. In particular, the manipulated variable, the feedback variable or the control difference allow

Conclusions about the penetration behavior of the ballast bed, from which a condition parameter of the ballast bed results.

Brief description of the drawings

[22] The invention is explained below by way of example with reference to the accompanying figures. It show in schematic

Presentation:

Fig. 1 tamping unit in side view

Fig. 2 control loop

Fig. 3 reference variable course

Fig. 4 modified reference variable profiles

Fig. 5 control circuit with pre-filter or pilot control

Fig. 6 control loop with adjustable pre-filter or adjustable

Feedforward control

Fig. 7 control loop with setpoint generator for generating a modified

Reference variable course Description of the embodiments

The tamping unit 1 shown in FIG. 1 comprises a unit frame 2 which is fastened to a machine frame 3 of a track construction machine which can be moved on rails 4 of a track 5. The tamping unit 1 is used for tamping a ballast bed 6 on which sleepers 7 with the rails 4 of the track 5 fastened thereon are mounted. A tool carrier 8 is guided in a height-adjustable manner in the unit frame 2, a lowering movement 9 or lifting movement being carried out by means of an associated height adjustment drive 10.

[24] On the tool carrier 8, an oscillation drive 11 is arranged, to which two auxiliary drives 12 are connected. Each auxiliary drive 12 is connected to a pivot lever 13. Both swivel levers 13 are

mounted to each other about a respective horizontal pivot axis 14 on the tool carrier 8 and have tamping tools 15 (tamping pick). The drives 10, 11, 12 are controlled by means of a

Control device 16.

[25] The free ends of the tamping tools 15 (pimple plates) penetrate into the ballast bed 6 during a tamping process below a lower threshold edge and compact the ballast under the relevant threshold 7. FIG. 1 shows the tamping unit 1 during such a phase of the tamping process. The tamping tools 15 are then reset and lifted out of the ballast bed 6. The tamping unit 1 is moved to the next threshold 7 and a new tamping cycle begins with a lowering movement 9.

[26] With an optimized lowering movement 9, the desired immersion depth 17 of the tamping tools 15 is reached as quickly as possible, however, the forces occurring do not cause disruptive loads on the track construction machine. In addition, the immersion depth 17 should be reached exactly and not exceeded, in order to neither the thresholds 7 nor one below the

Damage gravel bed 6 located subgrade.

This optimized lowering movement 9 is achieved according to the invention by a control circuit set up in the track-laying machine with a controller 18, an adjusting device 19 for the height adjustment drive 10 and a measuring device 20 for detecting the lowering movement 9 (FIG. 2). To the Specifying the course of the lowering movement 9 provides, for example, a

Setpoint generator 21 is a setpoint curve shown in FIG. 3 for a

Controlled variable x. Several can also be set in the setpoint generator 21

Setpoint curves must be stored. A selection is made using a

intelligent control assuming at least one track parameter or by an operator. The output of the setpoint generator 21 serves as a reference variable w of the control loop. For example, a lowering path s of the tool carrier 8 is provided as the controlled variable x. The speed and / or the acceleration of the tool carrier 8 can also be used as the controlled variable x.

[28] The controller 18 comprises a control element 22 and supplies one

Controller output variable y, which is fed to an actuator 23 to form a manipulated variable u. A pilot-controlled control valve for a hydraulic cylinder of the flute adjustment drive 10 is used, for example, as the actuating device 19. The actuator 23 is then an actuator of this pilot-controlled control valve and controls a control path of the control valve as a manipulated variable u. A present controlled system 24 comprises as actuator 25 the valve body of the control valve and all other components influencing the lowering movement 9. These include the hydraulic cylinder of the flute adjustment drive 10 and all lowered components of the tamping unit 1 as well as components of the processed area of the track 5. In particular, the masses of the lowered components and the resistance to penetration of the ballast bed 6 come into play here.

[29] The controller output variable y output by the control element 22 is based on a control difference e which results from the reference variable w minus a feedback variable r. The feedback variable r is the controlled variable x detected by the measuring device 20. Specifically, the controller 18 determines a numerical manipulated variable (numerical value of) from a difference between a target value (numerical value of the command variable w) and an actual value (numerical value of the measured control variable x)

Controller output variable y), which is given to the actuator 23.

[30] Disturbances z act on the controlled system 24. It is about

in particular, a change in the penetration resistance as a result of itself changing nature of the ballast bed 6. The by a

changed penetration resistance caused disturbance of the controlled variable x results in a control difference e. The manipulated variable u then supplied by the controller 18 and the actuator 23 causes the height adjustment drive 10 to be actuated differently, as a result of which the malfunction is counteracted.

For example, if the tamping tools 15 penetrate too quickly into the ballast bed 6, one of the height adjustment drives 10 on the

Tool carrier 8 acting force reduced. If the penetration is too slow, the force is increased. In this way, the lowering movement 9 is always readjusted to the specified command variable w in the event of target deviations. The tamping tools 15 penetrate the ballast bed 6 at the optimum speed and reach the desired penetration depth 17 exactly.

The penetration time in the individual tamping cycles is also kept constant.

[32] In order to minimize the interference of the regulation, it makes sense for the

Command variable w to provide a pilot control or a prefilter 26 (FIG. 5). The aim of this measure is a modified reference variable w ', which anticipates the conditions of the controlled system 24. For example, for the lowering path s given as control variable x, a modified curve profile is given over time t, as shown in FIG. 4. The system consisting of tamping unit 1 and processed track 5 then follows this modified reference variable specification with almost no control intervention.

[33] The course drawn with a solid line is provided for a soft ballast bed 6 with weakly compacted ballast. The other courses correspond to specifications for an increasingly compacted ballast bed 6, up to the dotted course for a very strong one

compacted ballast bed 6. To the here in the allotted time

To achieve the desired penetration depth 17, a higher speed is required in the start phase of the penetration.

[34] Another improvement sees a parameter adjustment of the

Pre-control or pre-filter 26 before, as shown in Fig. 6. For this purpose, a computing unit 27 is provided, to which a control difference e _k occurring during a stuffing cycle k is supplied. This control difference e _k results from the unmodified reference variable W _k minus the

Feedback variable r _k .

[35] In the computing unit 27 is a so-called iterative learning control

Algorithm 28 set up. This is used to use the

Control difference e _k and the modified command variable w ' _k of the stuffing cycle k in question derive an optimized modified command variable w' _{k + i} for the next stuffing cycle k + 1. For this calculation, several past tamping cycles with the ones that occur can also be used

Control differences e can be used.

[36] So the optimized modified reference variable w ' _{k + i} for use

comes, the setting parameters of the

Precontrol or prefilter 26 changed. For this purpose, a corresponding setting algorithm 29 is set up in the computing unit 27. The changed pilot control or the changed prefilter 26 brings about a reduction in the control activity, as a result of which the control as a whole is more stable.

Initial conditions for the iterative learning control algorithm 28 are either specified by an operator or an assumption is made using an intelligent control. The iterative

Adjustment of the parameters then starts from this specification. In a simple variant, the initial conditions are always the same

went out.

[37] Another improvement will be explained with reference to FIG. 7. Here, the setpoint generator 21 is designed as a setpoint generator. Similar to one

Trajectory generator, this setpoint generator generates a course of the lowering movement 9, for example as a course of the lowering path s over time t. In this way, the setpoint generator supplies the control variable w to the controller 18 or the pilot control or the prefilter 26. In addition, the feedback variable r is fed to the setpoint generator in order to detect deviations from the reference variable w. Here, too, initial conditions are specified either by an operator or by intelligent control based on assumed track parameters.

[38] Increasing deviations indicate that the regulation has reached its limits because the generated reference variable w can no longer be reached is. As soon as the deviations reach a level that can no longer be neglected, the setpoint generator generates a new specification for the

Lowering movement 9. For example, there is a limit for permissible

Deviations predefined so that the setpoint generator generates a new course of the lowering path s over time t when the limit value is reached. In this way it is automated to a changed

Texture of the ballast bed 6 reacts without the stability and

Affect the accuracy of the control.

[39] The setpoint generator can also be used at the start of a work assignment

Application come to specify a starting sequence of the lowering movement 9. It is beneficial if several trial tamping

be carried out to meet the requirements for the scheme

to adapt to prevailing conditions.

[40] The electronic components of the scheme, particularly the

Setpoint generator 21, controller 18 and possibly computing unit 26 are set up in a separate electronic circuit or integrated in control device 16. The arrangement of the measuring device 20 takes place, for example, directly on the height adjustment drive 10, with a

Hydraulic cylinder with integrated distance measurement makes sense.

[41] In addition, in an extended embodiment, an evaluation device 30 is provided, to which at least one variable u, e, r of the control loop is supplied in order to derive a parameter for the ballast bed 6. Such

A parameter indicates, for example, whether it is new ballast or heavily compacted and contaminated ballast.

Claims

1. Track construction machine with a tamping unit (1) for tamping sleepers (7) of a track (5) lying in a ballast bed (6), comprising a tool carrier (8) mounted on a unit frame (2) with adjustable height, on the tamping tools (15) are arranged to each other, the

Tool carrier (8) with a by means of a control device (16)

controlled height adjustment drive (10) is coupled, thereby

characterized in that for regulating a lowering movement (9) of the

Tool carrier (8), a control circuit with a controller (18), an adjusting device (19) for the height adjustment drive (10) and a measuring device (20) for detecting the lowering movement (9) is set up.

2. Track construction machine according to claim 1, characterized in that the measuring device (20) comprises a position transmitter for detecting a height position of the tool carrier (8).

3. Track construction machine according to claim 1 or 2, characterized in that the controller (18) is preceded by a pilot control (26) or a pre-filter (26) by means of which a reference variable (w) can be adjusted.

4. Track construction machine according to one of claims 1 to 3, characterized

characterized in that the height adjustment drive (10) comprises a hydraulic cylinder with a hydraulic valve as the adjusting device (19).

5. Track construction machine according to claim 4, characterized in that the hydraulic valve is designed as a pilot-controlled control valve.

6. A method for operating a track construction machine according to one of claims 1 to 5, characterized in that the tamping unit (1) over a

Darning point of the track (5) is positioned and that the tool carrier (8) via the height adjustment drive (10) also penetrate into the ballast bed (6) Darning tools (15) lowered and the lowering movement (9) is carried out with a controlled movement size (x, s).

7. The method according to claim 6, characterized in that a reference variable (w) is modified by means of a pilot control (26) connected upstream of the controller (18) or by means of a pre-filter (26) connected upstream of the controller (18).

8. The method according to claim 7, characterized in that a control difference (ek) occurring during a stuffing cycle (k) is fed to a computing unit (27) and that starting from the control difference (ek) in the computing unit (27) by means of an iterative learning control Algorithm (28) at least one

Parameter (p) of the pilot control (26) or the pre-filter (26) is adjusted.

9. The method according to any one of claims 6 to 8, characterized in that the lowering movement (9) of the tool carrier (8) by means of a

Position sensor is detected.

10. The method according to any one of claims 6 to 9, characterized in that the control loop is given a reference variable (w) which is dependent on a lowering time (t).

11. The method according to claim 10, characterized in that the

Control loop a lowering path (s) over the lowering time (t) is specified as a reference variable (w).

12. The method according to any one of claims 6 to 11, characterized in that a setpoint curve is specified by means of a setpoint generator (21).

13. The method according to claim 12, characterized in that a feedback variable (r) of the control loop is supplied to the target value generator (21) designed as a target value generator and that the predetermined lowering movement (9) is adapted as a function of the feedback variable (r).

14. The method according to any one of claims 6 to 13, characterized in that at least one of the variables processed in the control loop one

Evaluation device (30) is supplied and that by means of the evaluation device (30) a parameter for the ballast bed (6) is derived from the at least one size.