Method for operating a tamping machine and a tamping machine for carrying out said method

Abstract

A method for operating a tamping machine (1) on a track (4), the tamping machine (1) comprising a tamping unit (9), a lifting / straightening unit (8), a measuring system (11) with measurement sensors (14) and an open / closed loop control (15), the lifting / straightening unit (8) being driven and controlled by the open / closed loop control (15) depending on the track position detected by means of the measuring system (11) so that the track section to be treated is lifted to a target level during a lifting time, wherein a selection is made between at least two controllers (19, 21) provided in the open / closed loop control (15) such that a first controller (19) is operated in a first lifting mode for standard operation and a second controller (21) is operated in a second lifting mode for a switch, each controller (19, 21) being optimized for the associated closed loop control system. Additionally, a tamping machine is provided for carrying out the method.

Description

[Technical field]

[0001] The invention relates to a method for operating a tamping machine on a track, the tamping machine comprising a tamping unit, a lifting / straightening unit, a measuring system with measurement sensors and an open / closed loop control device, the open / closed loop control device drivingly controls the lifting / straightening unit depending on the track position detected by the measuring system, so that the track section to be treated is lifted to a target level during the lifting time. The invention further relates to a tamping machine for carrying out the method. [Background technology]

[0002] Tamping machines have been known for some time and are used to create or restore a preset track position on a track laid on a ballast bed. In operation, the tamping machine travels over the track and a lifting / straightening unit lifts the track section located between the two rail running gears. The lifting performed is detected by a machine-specific measuring system. An open-loop / closed-loop control device controls the drive of the lifting / straightening unit and raises the track to a preset target level in a closed control loop. Such a method is known, for example, from AU Patent No. 369455.

[0003] It must be noted that in such a closed control loop for track lifting according to the prior art, when correcting the position of the turnout, a relatively long lifting duration occurs due to a relatively large weight in order to reach a preset target level, and therefore the desired track position can only be fixed after lifting with the tamping unit, resulting in a correspondingly long tamping cycle for the turnout. Summary of the Invention [Problem to be solved by the invention]

[0004] The object of the invention is to improve the method of the type mentioned at the beginning in such a way that an efficient lifting process can also be carried out at switches. It is furthermore the object of the invention to provide a corresponding tamping machine. [Means for solving the problem]

[0005] According to the invention, these problems are solved by the characterizing features of the independent claims 1 and 12. The dependent claims give advantageous embodiments of the invention.

[0006] Here, a selection is made between at least two controllers provided in the open-loop / closed-loop control device, such that in a first lifting mode for standard operation the first controller is activated and in a second lifting mode for switches the second controller is activated. Each controller is optimized for the associated closed-loop control system. For a simple track, where a track frame consisting of sleepers and two rails is lifted, the first controller is used. For a switch, where the closed-loop control system has different characteristics, the second controller is used. This results in approximately the same lifting duration and control quality for the two closed-loop control systems. The controller can further be set in such a way that in the two lifting modes no overloading of the machine and the track or the switch occurs. For example, in the second lifting mode, higher lifting forces occur which may cause overloads or strong over-vibrations in a simple track.

[0007] In one development of the method, in particular a P controller is operated as the first controller and a PD, PI or PID controller is operated as the second controller. A P controller (proportional controller) is used in the track section between the switches. A P controller is easy to set and gives sufficiently good results for standard operation. However, at the switches, this first controller increases the lifting duration prohibitively. Therefore, in the second lifting mode, a PD, PI or PID controller (a controller with proportional and integral components or a controller with integral and differential components) is used. Such a controller can be set exactly depending on the situation present at the switch, so that shorter lifting times are obtained with a larger lifting force, but with the same quality. In another feature, it may also be useful to configure the first controller as a PD, PI or PID controller. This can ensure a more precise drive control of the lifting / leveling unit, possibly even in the section area.

[0008] Another improvement is to compare the track lifting amount detected by the measurement sensor with a preset threshold value and generate an electronic authorization to lower the tamping unit onto the track ballast bed as soon as the threshold value is reached, thus achieving protection of the tamping unit and the track bed, since the actual tamping process starts with the lowering and squeezing of the tamping tool only when the track lifting has progressed sufficiently. For example, the authorization is given when 95% of the desired lifting amount has been achieved.

[0009] In one simple aspect of this refinement, the operator is informed of the permission to lower the tamping unit by an permission signal, which is immediately followed by the operator activating the height drive of the tamping unit, and the operator is informed, for example, acoustically and / or optically, that the desired lifting is taking place or that a preset threshold (e.g. 90%) has been reached depending on the desired lifting.

[0010] In an alternative variant of the method, the height drive of the tamping unit is automatically activated as soon as the activation permission for lowering the tamping unit is given, which variant is effective when the method is used within the framework of an automated tamping process or with the aid of an assistance system.

[0011] In any case, it is advantageous if a warning signal is generated immediately before the tamping unit is lowered, in this way all machine operators are acoustically and / or optically warned before the tamping unit is activated.

[0012] Advantageously, the first lifting mode or the second lifting mode is activated by means of an operating element, so that the operator can switch between the two lifting modes at any time, preferably with the operator being informed which lifting mode is better suited to the current situation.

[0013] Additionally or alternatively, it is preferable to detect the lifting force and / or lifting time acting on the track by the lifting / levelling unit and possibly by an additional lifting unit and to automatically switch from one lifting mode to another if a threshold value is reached, which reduces the burden on the operator and leads to a fast and reliable selection of the correct lifting mode.

[0014] What is expedient here is that a comparator is used to compare the detected lifting force with a lifting force limit value and, if a preset lifting amount is reached, a selection signal is generated at the output of the comparator in order to activate the first lifting mode if the measured lifting force is below the lifting force limit value and the second lifting mode if it exceeds the lifting force limit value. The lifting force is then used as a reliable variable for selecting the lifting mode. As soon as the tamping machine enters the switch area, the required lifting force increases, so that if the limit value is exceeded, a switchover to the second lifting mode takes place. Conversely, when leaving the switch area, the limit value is reached from above and the first lifting mode is resumed.

[0015] To further improve the method, the open-loop / closed-loop control device is preset with position data of the track for switching from one lifting mode to another. By comparing the position data stored in the electronic memory with the detected actual position, the switching between the two lifting modes can be performed reliably.

[0016] Preferably, a sensor arranged on the tamping machine is used to detect the beginning or end of the switch and transfer a corresponding signal to the open-loop / closed-loop control device. This achieves a degree of automation that significantly reduces the burden on the user. The automatically running process is shown to the user for monitoring and, if necessary, intervention.

[0017] In a tamping machine according to the invention for implementing one of the described methods, the open-loop / closed-loop control system is provided with at least two controllers, a first controller being associated with a first lifting mode for standard operation and a second controller being associated with a second lifting mode for switches, such a tamping machine allows an optimal lifting process to be performed for all sections of the track installation during track position correction.

[0018] Advantageously, the open-loop / closed-loop control device is provided with, in particular, a P-controller as the first controller and a PD-, PI- or PID-controller as the second controller, which are designed in such a way that for the respective closed-loop control system, a high closed-loop control quality is achieved with short lift-off times, which leads to short overall tamping cycle times and shorter working times, both on the track section and at the switch.

[0019] The second controller preferably includes a parallel circuit of P, I and D elements, which allows the second controller to be flexibly adapted to the splitter to be processed. The individual elements of the controller can be changed separately to optimize the characteristics of the controller.

[0020] To further improve the tamping machine, sensors for recognizing the switch are arranged in front of the lifting / straightening unit in the working direction, in particular cameras, 2D laser scanners and / or 3D laser scanners. These auxiliary devices make it possible to achieve a large degree of automation of the tamping process. In particular, the start and end of the switch are identified, so that switching between the two lifting modes takes place automatically.

[0021] The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: FIG. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a schematic diagram showing a tamping machine on a track. [Diagram 2] FIG. 2 is a schematic diagram showing a proportional controller. [Diagram 3] FIG. 2 is a schematic diagram showing a controller structure including a first controller and a second controller. [Figure 4] FIG. 1 is a schematic diagram showing a block diagram for automatic selection of lift-up mode. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The tamping machine 1 shown in Fig. 1 includes a machine frame 2 that is supported on rail running gear 3 and can run on a track 4. The track 4 has a track frame formed of sleepers 5 and rails 6 fixed to the sleepers 5, and the track frame is laid on a ballast bed 7. The sections of the track 4 are divided into simple track sections, switches, and crossings. In such a position correction of track equipment, the tamping machine 1 has to process various track sections, in particular simple track sections and switches.

[0024] A lifting / straightening unit 8 and a tamping unit 9 are arranged on the machine frame 2 of the tamping machine 1. The auxiliary lifting unit 10 is used to lift the rail section branching off at the turnout. The lifting of the track section or the turnout by the lifting / straightening unit 8 and possibly the auxiliary lifting unit 10 is carried out in conjunction with a machine-specific measuring system 11. In the simplest case, this measuring system 11 comprises a wire cord 12 which is stretched across the respective rail 6 and between measuring axles 13 which are guided along the track 4. Other measuring systems 11 can also be used for the method, in particular optical measuring systems with optical measuring strings and a camera system with pattern recognition.

[0025] In any case, the measuring system 11 comprises a measurement sensor 14, which detects the height position of the track 4 in the area of ​​the lifting / straightening unit 8. For example, a further measuring axle 13 is arranged, by means of which the change in the distance of the rail 6 to the wire cord 12 used as reference element is determined via a rod. For this purpose, the measurement sensor 14 comprises a rotary potentiometer, which engages in a form-fitting manner with the respective wire cord 12 via a fork-shaped guide. In the case of an optical measuring system, the measurement sensor 14 is, for example, an image sensor for evaluating an optical signal.

[0026] An open-loop / closed-loop control device 15 is provided for controlling the lifting / straightening unit 8. This controls, for example, a proportional valve which is associated with a hydraulic lifting drive 16 of the lifting / straightening unit 8. A closed control loop is provided for lifting the track section or the switch. The system consisting of the track or the switch and the lifting device forms a closed-loop control system on which various disturbance quantities can act.

[0027] In particular, the lift quantity, which is detected by the measurement sensor 14, is used as the control variable. The corresponding measured value 17 of the lift quantity is fed back and compared with a set lift value 18 as a reference variable. The set lift value 18 is derived from the desired track position and is predefined in the open-loop / closed-loop control device 15, for example by means of a master computer. The control deviation resulting from the measured value 17 and the set lift value 18 is used as input for a controller 19, which is for example designed as a P controller (FIG. 2). A control signal 20, for example a drive control voltage for a hydraulic valve of the lift drive 16, is applied to the output of the controller 19. In this way, the currently processed track section is lifted to the set level in a closed-loop controlled lift process.

[0028] According to the invention, the open-loop / closed-loop control device 15 is provided with at least two controllers 19, 21. A corresponding embodiment is shown in Fig. 3. As shown in Fig. 3, the input signal for the controllers 19, 21 is a control deviation formed from the measured value 17 and the desired lift value 18. The first controller 19 is, for example, a P-controller (P-element 22), which generates at its output a control signal 20 for a first lift mode for standard processing of the track section.

[0029] The second controller 21 is, for example, a PID controller with a parallel circuit of a P element 22, an I element 23 and a D element 24. These elements 22, 23, 24 of the second controller 21 are coordinated with each other to achieve an optimal lift of the branch. The sum of the output signals forms the manipulated variable 20 which is generated by means of the second controller 21.

[0030] By means of a selection signal 25 and a switch element 26, one of the outputs of the two controllers 19, 21 is enabled, so that either a first lifting mode for standard operation or a second lifting mode for the switch is activated. In the simplest case, the selection signal 25 is determined by means of an operating element, so that the operator 27 has an unobstructed view of the section to be processed.

[0031] Advantageously, the tamping machine 1 is provided with technical devices to assist the operator 27 or to automate the selection process. For example, a camera 29 is arranged in front of the lifting / straightening unit 8 in the working direction 28 for detecting the track 4. The recorded images are transmitted in real time to a computer 30, which is provided with analysis software. By means of pattern recognition, it is automatically identified where the switch area begins and where it ends. Via a distance measuring device 31, the current positions of the lifting / straightening unit 8 and the auxiliary lifting unit 10 in relation to the identified switch are known.

[0032] As a sensor for identifying the switches, for example, a 2D laser scanner 32 is also used, which is positioned on the rail 6. This identifies the tongue rail, the diverging rail or the wheel fork. A 3D laser scanner (rotating scanner) 33 arranged on the end face of the tamping machine 1 detects a three-dimensional image of the traveled track area, from which the start and end of the switch can likewise be determined.

[0033] Another aid is a GNSS receiver 34, which determines the exact position of the tamping machine 1 via a navigation satellite system. The open / closed loop control device 15 stores switch position data, which identifies when the machine 1 has entered or left a switch by comparing it with the current position.

[0034] For the automatic changeover of the lifting mode, it is useful to detect the lifting force and / or the lifting duration acting on the track or on the turnout by the lifting / straightening unit 8 and possibly by the auxiliary lifting unit 10. When a predefined limit value is reached, the changeover from one lifting mode to the other takes place automatically. For measuring the lifting force, for example, a force measuring cell is arranged. As a sensor for detecting the lifting force, a pressure sensor 35 is also suitable, which measures the hydraulic pressure in the hydraulic lifting drive of the lifting / straightening unit 8. For example, in standard operation the lifting force amounts to about 100 kN. This corresponds to a hydraulic pressure of about 100 bar. This results in a lifting duration of 0.5 to 1 second for a simple track section. For a turnout, the lifting force is approximately doubled and the lifting duration is 1 to 4 seconds.

[0035] The automatic switching is explained in more detail with reference to FIG. 4. A comparator 36 compares the measured lifting force 37 with a lifting force limit value 38. A status signal 39 indicates that the preset target lifting value 18 has been reached. As soon as a corresponding notification is made, the lifting mode is determined. If at this point in time the measured lifting force 37 is less than or equal to the lifting force limit value 38, the comparator 36 generates a selection signal 25 for activating the first lifting mode for standard operation. However, if at this point in time the measured lifting force 37 is greater than the lifting force limit value 38, then at the output of the comparator 36 a selection signal 25 for activating the second lifting mode for the switch is applied. The preset lifting force limit value 38 is, for example, in the range 100 kN to 130 kN, preferably 110 kN.

[0036] Additionally arranged in the operator's cabin 40 is a display 41, which shows the results of the sensors 29, 32, 33, 35 and the automatic selection of the lifting mode. The operator 27 can also be directed to a particular process by acoustic messages.

[0037] Furthermore, the point in time when the lifting amount has reached a preset threshold value (e.g. 95%) is indicated to the operator 27 and the activation of the tamping unit 9 is permitted. In this case, the height drive 42 of the tamping unit 9 is activated by the operator 27 or automatically. This ensures that the tamping unit 9 is lowered into the ballast bed 7 only when lifting has progressed sufficiently. This ensures a continuous tamping process in which the lowering process is directly followed by the squeezing process of the tamping tool 43. In this way, both the tamping unit 9 and the ballast bed 7 are protected.

[0038] To warn further operating operators of the operation of the tamping unit 9, an acoustic warning device 44 is arranged on the tamping machine 1. Furthermore, an optical warning device 45 may be fitted, thereby ensuring that personnel on the track 4 are not exposed to danger due to the automated course of the tamping process.

Claims

1. A method for operating a tamping machine (1) on a track (4), the tamping machine (1) comprising a tamping unit (9), a lifting / leveling unit (8), a measuring system (11) with measurement sensors (14), and an open-loop / closed-loop control device (15), the open-loop / closed-loop control device (15) driving and controlling the lifting / leveling unit (8) depending on the track position detected by the measuring system (11) so that the track section to be treated is lifted to a target level during a lifting time, a method for selecting between at least two controllers (19, 21) provided in the open-loop control / closed-loop control device (15) such that a first controller (19) is operated in a first lifting mode for standard operation and a second controller (21) is operated in a second lifting mode for a turnout.

2. 2. The method according to claim 1, characterized in that a P-controller is operated as the first controller (19) and a PD-controller, a PI-controller or a PID-controller is operated as the second controller (21).

3. 3. The method according to claim 1, further comprising the step of comparing the amount of lifting of the track (4) detected by the measurement sensor (14) with a preset threshold value, and generating an authorization for lowering the tamping unit (9) onto the ballast bed (7) of the track (4) as soon as the amount of lifting reaches the threshold value.

4. 4. The method according to claim 3, characterized in that an activation permission signal is used to notify an operator (27) of the activation permission for lowering the tamping unit (9), and the operator (27) activates a height drive (42) of the tamping unit (9).

5. 4. A method according to claim 3, characterized in that the height drive (42) of the tamping unit (9) is automatically activated as soon as the activation permission for the lowering of the tamping unit (9) is given.

6. 4. A method according to claim 3, characterized in that a warning signal is generated immediately before said lowering of said tamping unit (9).

7. 2. The method according to claim 1, wherein an operating element is used to activate the first lifting mode or the second lifting mode.

8. 2. The method according to claim 1, characterized in that the lifting force and / or the duration of the lifting exerted on the track by the lifting / levelling unit (8) and possibly by an auxiliary lifting unit (10) is detected and, if a threshold value is reached, the method automatically switches from one lifting mode to the other.

9. 9. The method according to claim 8, further comprising the step of comparing the detected lifting force with a lifting force limit value (38) using a comparator (36) and, if a preset lifting amount has been reached, generating a selection signal (25) at the output side of the comparator (36) so as to activate the first lifting mode if the lifting force measurement value (37) is less than or equal to the lifting force limit value (38) and to activate the second lifting mode if the lifting force measurement value (37) exceeds the lifting force limit value (38).

10. 2. The method according to claim 1, wherein the open-loop / closed-loop control device (15) is preset with position data of the track (4) for switching from one lifting mode to the other lifting mode.

11. 2. The method according to claim 1, characterized in that a sensor (29, 32, 33) arranged on the tamping machine (1) is used to detect the beginning or end of a switch and to transmit a corresponding signal to the open-loop control / closed-loop control device (15).

12. 2. A tamping machine (1) for carrying out the method according to claim 1, characterized in that the open-loop control / closed-loop control device (15) is provided with at least two controllers (19, 21), a first controller (19) being associated with a first lifting mode for standard operation, and a second controller (21) being associated with a second lifting mode for a switch.

13. The tamping machine (1) according to claim 12, characterized in that the open-loop control / closed-loop control device (15) is provided with a P controller as the first controller (19) and a PD controller, a PI controller or a PID controller as the second controller (21).

14. 14. The tamping machine (1) according to claim 13, characterized in that the second controller (21) includes a parallel circuit of a P element (22), an I element (23) and a D element (24).

15. 15. The tamping machine (1) according to any one of claims 12 to 14, characterized in that a sensor for identifying the turnout, in particular a camera (29) and / or a 2D laser scanner (32) and / or a 3D laser scanner (33), is arranged.

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