Method for reducing a longitudinal vibration in a train, and train comprising means for carrying out the method

Abstract

In one aspect, the invention relates to a method for reducing a longitudinal vibration (LS) in a train (ZG), wherein the train has at least one driven unit (AE) and at least one rail vehicle (WA) connected thereto. A movement force (AK-AE) is applied to the train (ZG) in order to drive the train (ZG) in a targeted manner or to brake the train (ZG) in a targeted manner. A longitudinal vibration (LS) occurring in the train is detected. A temporal progression (t(LS)) of the longitudinal vibration (LS) is determined and fed to an algorithm (ALG). A counterforce (DAK-AE) is determined by the algorithm (ALG) in such a way that the counterforce (DAK-AE), by being combined with the movement force (AK-AE), dampens the longitudinal vibration (LS). The counterforce (DAK-AE) is applied as a braking force by a rail vehicle (WA) of the train (ZG) in order to reduce the longitudinal vibration (LS) in the train. In a further aspect, the invention relates to a train comprising means which are designed to carry out the method.

Description

METHOD FOR REDUCING A LONGITUDINAL VIBRATION FOR A TRAIN, AND TRAIN COMPRISING MEANS FOR CARRYING OUT THE METHOD The invention relates to a method for reducing a longitudinal vibration for a train that comprises at least two rail vehicles coupled to one another. Introduction It is known that a train that comprises, for example, at least two cars coupled or connected to one another as elements can experience a longitudinal vibration. The longitudinal vibration arises as a result of the coupled elements of the train interacting via coupling elements that are used and is also dependent, inter alia, on a speed of travel of the train. The longitudinal vibration generates forces that additionally act on the coupling elements used and may place them under stress. If a coupling element has its stress limit exceeded, breakage of the coupling element may cause train separation. In particular trains consisting of tank cars are susceptible to such longitudinal vibration, which preferably arises when the train starts up. This problem is currently solved by virtue of an engineer of the train identifying an occurring longitudinal vibration and accordingly taking targeted countermeasures: in order to reduce the longitudinal vibration, he / she slows the train based on their experience in train operation or accelerates the train as appropriate. In summary, when a longitudinal vibration occurs, he / she opposes a motive force of the train that drives or slows the train with a counterforce that, in conjunction with the motive force, causes the longitudinal vibration to be damped. This approach is thus based on early identification of the longitudinal vibration by the engineer of the train and on their experience, in order firstly to sufficiently reduce the longitudinal vibration and secondly to maintain safe operation of the train. This intervention by the engineer disadvantageously causes a perceptible change in train dynamics and an increased energy consumption. Owing to the "human factor" and owing to the possibilities that there are for the longitudinal vibration to form and be reduced, this approach is not very well developed and not very satisfactory. Objective It is therefore the object of the present invention to specify an improved method for reducing an occurring longitudinal vibration for a train. This object is achieved by the features of claim 1. Advantageous developments are specified in the dependent claims. Invention The inventive method for reducing a longitudinal vibration relates to a train that comprises at least two rail vehicles connected to one another. The train has a motive force applied to it in order to drive the train in a deliberate manner or in order to slow the train in a deliberate manner. The motive force allows normal or trouble-free train operation. A longitudinal vibration arising for the train is detected as a disruption to train operation. A time characteristic of the longitudinal vibration is determined and fed to an algorithm. The algorithm determines a counterforce such that the counterforce, when superimposed on the motive force, causes the disruptive longitudinal vibration to be damped. The counterforce thus determined is implemented as a braking force by a rail vehicle of the train in order to reduce the disruptive longitudinal vibration in the train. In a preferred development, the braking force is implemented using a braking system that allows instantaneous or virtually instantaneous implementation of a braking effect in the train. Such a braking system is referred to as a "highly dynamic braking system". Compared to a known, pneumatically actuated or pneumatically controlled braking system, a highly dynamic braking system uses a reduced number of pneumatic components and is preferably in the form of a compressed-air-free braking system. Reducing pneumatic components or completely dispensing with pneumatic components allows instantaneous or virtually instantaneous implementation of the braking effect in the train. In a preferred development, a braking system is used that is electronically controlled and / or that uses electronic components to implement the braking force. This permits smooth and precise implementation of the braking effect in the train. In a preferred development, the time characteristic of the longitudinal vibration is determined in amplitude and frequency. In a preferred development, the longitudinal vibration is detected, and / or the time characteristic of the longitudinal vibration is determined, using a sensor. In a preferred development, the braking force is superimposed on the motive force as a time characteristic. In a preferred development, the braking force is determined and / or superimposed and / or implemented in the train in an automated manner. This is done in particular without the involvement of an engineer of the train. In a preferred development, the algorithm is tailored to an operating behavior of the braking system in order to take into account previously known time delays for the braking force implementation in the train. This also includes a time delay when the counterforce is routed from a braked wheelset to an element that makes a connection between the rail vehicles, e.g. a buffer on a car body. In a preferred development, the algorithm is tailored to an operating behavior of the train in order to take into account previously known time delays for the counterforce implementation in the train in that case too. In a preferred development, the sensor used is an acceleration sensor. In a preferred development, the sensor used is a sensor that is arranged close to or on a coupling that connects two adjacent rail vehicles of the train to one another. In a preferred development, it is determined which rail vehicle of the train is affected by the longitudinal vibration in order to selectively address the implementation of the braking force for the rail vehicle. In a preferred development, it is determined which rail vehicle of the train is affected by the longitudinal vibration at which time in order to selectively address the implementation of the braking force for the rail vehicle. In a preferred development, the braking force is superimposed on the forces that act during normal train operation (such as the motive or driving force or a braking force currently applied by the rail vehicle). It acts as a damping force and reduces the longitudinal vibration. In this case, the brakes act as damping elements that convert or dissipate the energy of the longitudinal vibration. Advantages of the invention: The present invention provides a dependable and automated solution for reducing a longitudinal vibration in the train. The present invention delivers a reliable method for reducing the longitudinal vibration, which is carried out in an automated manner independently of the engineer. Manual intervention by the engineer according to the known prior art disadvantageously results in perceptible changes in train dynamics being caused. These disadvantageous changes are avoided by the present invention. The present invention allows gentle and yet effective implementation of the counterforce in an automated manner. The present invention influences train dynamics only insignificantly and achieves energy savings. Description of the figures The invention is explained in more detail below with the aid of a drawing, in which: FIG. 1 shows details pertaining to the present invention, FIG. 2 shows a flowchart for the present invention with reference to FIG. 1, and FIG. 3 to FIG. 6 show a longitudinal vibration arising and being reduced for the train. FIG. 1 shows details pertaining to the present invention. The method for reducing a longitudinal vibration LS is used for a train ZG that comprises a locomotive and rail vehicles WA connected thereto, in this case tank cars, as a driven unit AE. The driven unit AE has a motive force or a driving force AK-AE applied to it in order to influence the movement of the train ZG in a defined or deliberate manner in line with driving or braking. The driving force AK-AE may be the joint cause of an arising longitudinal vibration LS for the train ZG. The driving force AK-AE may be a force for accelerating or driving the train or a force for braking the train. The train ZG uses sensors SEN to detect the longitudinal vibration LS occurring in the train ZG. The sensors SEN used in this case are acceleration sensors. In this case, sensors SEN are arranged on couplings KUP that connect adjacent rail vehicles WA of the train ZG. The train ZG determines a time characteristic t(LS) of the longitudinal vibration LS (preferably in frequency f(LS) and amplitude A(LS)) and feeds it to an algorithm ALG, which in this case, by way of illustration, is part of a control system of the driven unit AE. In the case of a multiple-unit train, the algorithm ALG could also be part of a car or a non-driven unit and be provided, for example, in an associated brake control unit. The algorithm ALG takes the time characteristic of the longitudinal vibration LS as a basis for determining a difference driving force DAK-AE as a counterforce or as a braking force for the rail vehicles of the train ZG in such a way that superimposition of the driving force AK-AE on the difference driving force DAK-AE reduces the longitudinal vibration LS. In summary, the braking force is superimposed on the forces that act during normal train operation (such as the driving force AK-AE, or a braking force currently applied by the rail vehicle). It acts as a damping force and reduces the longitudinal vibration LS. In this case, the brakes act as damping elements that convert or dissipate the energy of the longitudinal vibration. The algorithm ALG preferably begins by determining the coun terforce when a predetermined amplitude value for the longitudinal vibration LS is exceeded as a limit value. The difference driving force DAK-AE is a force for braking the train. Preferably, it is determined for the algorithm ALG which rail vehicles WA of the train are affected by the longitudinal vibration LS in order to selectively address the braking force as appropriate. The difference driving force DAK-AE is implemented as a counterforce by a compressed-air-free braking system BRS, which is a respective part of the rail vehicles WA. FIG. 2 shows a flowchart for the present invention with reference to FIG. 1. In a first step S1, the train ZG uses the sensor SEN to detect the longitudinal vibration LS occurring in the train ZG. In a second step S2, the train ZG determines the time characteristic t(LS) of the longitudinal vibration LS in frequency f(LS) and amplitude A(LS) and feeds it to the algorithm ALG. In a third step S3, the algorithm ALG takes the time characteristic t(LS) of the longitudinal vibration LS as a basis for determining a difference driving force DAK-AE for the driven unit AE of the train ZG in such a way that superimposition of the driving force AK-AE of the driven unit AE on the difference driving force DAK-AE reduces the longitudinal vibration LS in the train ZG. In a fourth step S4, the difference driving force DAK-AE is implemented as a braking force by a rail vehicle WA of the train ZG in such a way that the detected longitudinal vibration LS in the train ZG is reduced. FIG. 3 to FIG. 6 show a longitudinal vibration arising and being reduced for a train that consists of a locomotive and of four attached cars. FIG. 3 shows the train starting up as normal. There is not yet any longitudinal vibration in the train. The locomotive generates a tractive force that is passed on via the interfaces between the locomotive and / or between the cars in the train. The tractive force becomes ever smaller toward the end of the train. FIG. 4 and FIG. 5 show superimposition of forces when the train is starting up. The tractive force exerted by the locomotive during startup is superimposed with a dynamic tractive force and compressive force. As a result, groups of cars move relative to one another and thus 5 produce a wave of relative displacements of the cars that migrates through the train, said displacements forming a longitudinal vibration. FIG. 6 shows the longitudinal vibration being reduced for the train. If the time characteristic (frequency and amplitude) of the 10 longitudinal vibration is known, the rail vehicle as a braking unit is rendered able to use the principle of a damper to reduce the longitudinal vibration or keep it at a very low level.

Claims

1. A method for reducing a longitudinal vibration (LS) for a train (ZG), wherein the train comprises at least two rail vehicles (WA) connected to one another,- in which the train (ZG) has a motive force (AK-AE) applied to it in order to drive the train (ZG) in a deliberate manner or in order to slow the train (ZG) in a deliberate manner,- in which a longitudinal vibration (LS) arising for the train (ZG) is detected,- in which a time characteristic (t(LS)) of the longitudinal vibration (LS) is determined and fed to an algorithm (ALG),- in which the algorithm (ALG) determines a counterforce (DAK-AE) in such a way that the counterforce (DAK-AE), when superimposed on the motive force (AK-AE), causes the longitudinal vibration (LS) to be damped,- in which the counterforce (DAK-AE) is implemented as a braking force by a rail vehicle (WA) of the train (ZG) in order to reduce the longitudinal vibration (LS) in the train.2.The method as claimed in claim 1, in which the rail vehicle (WA) implements the counterforce (DAK-AE) using a braking system (BRS) that allows instantaneous or virtually instantaneous implementation of a braking effect in the train.3.The method as claimed in claim 1 or 2, in which the rail vehicle (WA) implements the counterforce (DAK-AE) using a compressed-air-free braking system.4.The method as claimed in claim 2 or 3, in which the braking system is electronically controlled and / or uses electronic components to implement the braking force.5.The method as claimed in claim 1, in which the longitudinal vibration (LS) is detected, and / or the time characteristic(t(LS)) of the longitudinal vibration (LS) is determined, using a sensor (SEN).6.The method as claimed in one of the preceding claims, in which the counterforce (DAK-AE) is superimposed on the motive force (AK-AE) as a time characteristic.

7. The method as claimed in one of the preceding claims, in whichthe counterforce (DAK-AE) is determined and / or superimposed and / or implemented in the train (ZG) in an automated manner.

8. The method as claimed in one of the preceding claims, in which the algorithm (ALG) is tailored to an operating behavior of the train or of the braking system in order to take into account previously known time delays for the counterforce implementation in the train (ZG).

9. The method as claimed in one of the preceding claims, in which the sensor used is an acceleration sensor.

10. The method as claimed in one of the preceding claims, in which the sensor (SEN) used is a sensor (SEN) that is arranged close to or on a coupling (KUP) that connects two adjacent rail vehicles (WA) of the train (ZG) to one another.

11. The method as claimed in one of the preceding claims, which involves determining which rail vehicle of the train is affected by the longitudinal vibration in order to selectively address the implementation of the braking force for the rail vehicle.

12. The method as claimed in one of the preceding claims, which involves determining which rail vehicle of the train is affected by the longitudinal vibration at which time in order to selectively address the implementation of the braking force for the rail vehicle.

13. The method as claimed in one of the preceding claims, in which the braking force is superimposed on the forces that act during normal train operation, such as the motive force or a braking force currently applied by the rail vehicle, in order to reduce the longitudinal vibration as a damping force.

14. A train comprising means designed to carry out the method as claimed in one of claims 1 to 13.

15. The train as claimed in claim 14,- in which the train (ZG) comprises at least two rail vehicles (WA) connected to one another,- in which the train (ZG) comprises motive force means that apply a motive force (AK-AE) to the train (ZG) in order to drive the train (ZG) in a deliberate manner or in order to slow the train (ZG) in a deliberate manner,- in which the train (ZG) comprises a detection means designed to detect a longitudinal vibration (LS) arising for the train (ZG),- in which the train (ZG) comprises a means for determining a time characteristic (t(LS)) of the longitudinal vibration (LS),- in which the train (ZG) comprises an algorithm (ALG) to which the time characteristic (t(LS)) of the longitudinal vibration (LS) is fed,- in which the algorithm (ALG) is designed to determine a braking force as the counterforce (DAK-AE) so that the counterforce (DAK-AE), when superimposed on the motive force (AK-AE), causes the longitudinal vibration (LS) to be absorbed, and- in which the train (ZG) comprises, on a rail vehicle, a means for implementing the counterforce (DAK-AE) so that the longitudinal vibration in the train is reduced.

16. The train as claimed in claim 14 or 15, in which, to implement the counterforce (DAK-AE), the rail vehicle (WA) has a braking system (BRS) arranged on it that allows instantaneous or virtually instantaneous implementation of a braking effect in the train.

17. The train as claimed in one of claims 14 to 16, in which, to implement the counterforce (DAK-AE), the rail vehicle (WA) has a compressed-air-free braking system (BRS) arranged on it.

18. The train as claimed in one of claims 14 to 17, in which, to implement the counterforce (DAK-AE), the rail vehicle (WA) has- an electronically controlled braking system (BRS) arranged on it, and / or- a braking system (BRS) that uses electronic components arranged on it.

19. The train as claimed in one of claims 14 to 18, in which a sensor (SEN), in particular an acceleration sensor, is arranged on the rail vehicle (WA) as the detection means for detecting the longitudinal vibration (LS) and / or as the means for determining the time characteristic (t(LS)) of the longitudinal vibration(LS).

20. The train as claimed in claim 19, in which the sensor (SEN) is arranged close to or on a coupling (KUP) that connects two adjacent rail vehicles (WA) of the train (ZG) to one another.5  21. The train as claimed in one of claims 14 to 20, in which thealgorithm (ALG) is tailored to an operating behavior of the train or of the braking system in order to take into account previously known time delays for the counterforce implementation in the train (ZG).10

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