Method and device for detecting derailment for rail vehicles, and rail vehicle
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- SIEMENS MOBILITY AUSTRIA GMBH
- Filing Date
- 2024-08-30
- Publication Date
- 2026-06-10
Smart Images
Figure EP2024074301_27032025_PF_FP_ABST
Abstract
Description
[0001] Method and device for derailment detection for rail vehicles and rail vehicle
[0002] The invention relates to a method for derailment detection for rail vehicles, wherein first bending deformations of the first holding element are detected by means of a first sensor, which is connected to a first holding element, and second bending deformations of the second holding element are detected by means of a second sensor, which is connected to a second holding element, wherein the first holding element and the second holding element are connected to an obstacle contact bar, which is held by means of the first holding element and the second holding element in front of a wheelset of a rail vehicle on a chassis of the rail vehicle and which, in the event of a derailment of the rail vehicle, forms a mechanical contact with a track body for the rail vehicle, whereby the first bending deformations and the second bending deformations are formed,and wherein the first sensor and the second sensor are connected to an evaluation unit for signal transmission.,
[0003] Rail vehicles must be highly safe to operate. Accurate assessment and prediction of the technical conditions of rail vehicles, bogies, and other rail vehicle components are therefore essential. Derailments, in particular, can cause serious damage to people and the environment, as well as to the rail vehicles themselves, which is why accurate and timely derailment detection is crucial.
[0004] From the prior art, for example, WO 2015 / 135752 A1 is known, which describes an obstacle detection device for rail vehicles. A track clearance beam is connected to a chassis frame of a rail vehicle's chassis via spring elements. Strain-stress transducers are connected to the spring elements, via which deformations of the spring elements, such as those that occur when a collision object impacts the track clearance beam, are recorded. The collision object can be characterized by evaluating a temporal progression of a collision force determined from the deformations. WO 2015 / 135752 A1 does not disclose any evaluation of the deformations of the spring elements with a view to detecting a derailment of the rail vehicle.
[0005] Furthermore, WO 2015 / 086456 A1 discloses a method for derailment detection and obstacle recognition for rail vehicles using a beam that is connected to a rail vehicle, arranged transversely to a track axis and above the top edge of the rail. Deflections of the beam can be detected by sensors. If the beam deflects vertically, this indicates a derailment of the rail vehicle. If the beam deflects in the direction of the track axis, it is assumed that this is due to a collision of the beam with an obstacle.
[0006] The invention is therefore based on the object of specifying a method for derailment detection which is more advanced than the prior art and independent of a railway superstructure.
[0007] According to the invention, this object is achieved by a method according to claim 1, in which, by means of the evaluation unit, first pulses with a first pulse effective direction parallel to a direction of travel of the rail vehicle are determined from the first bending deformations and second pulses with a second pulse effective direction parallel to the direction of travel are determined from the second bending deformations, wherein first pulse absolute values are formed from the first pulses and second pulse absolute values are formed from the second pulses, wherein as a first criterion for detecting the derailment of the rail vehicle, the first pulse absolute values and the second pulse absolute values on the one hand or sums of the first pulse absolute values and the second pulse absolute values on the other hand are compared with a pulse threshold value, whereby it is checked whether the first criterion is met, wherein the first criterion is then met,if the first pulse absolute values and / or the second pulse absolute values on the one hand or the sums on the other hand are equal to or greater than the pulse threshold.
[0008] This measure eliminates the need for complex evaluations of vertical accelerations of a chassis (e.g., to determine the falling speed and / or height of a wheel, etc.). Furthermore, the method can be used for various types of rail vehicles (e.g., mainline vehicles, subway vehicles, etc.) and track structures (e.g., ballasted track or slab track, etc.).
[0009] Derailment detection can, for example, be triggered by a scenario in which the obstacle contact bar hits a track or a conductor rail laid between two rails of the track, etc. It is also possible for the method to be implemented, for example, in conjunction with devices already present on a rail vehicle (e.g., a track clearance bar, an obstacle detection bar, etc.), thereby avoiding the provision of dedicated devices that, for example, have to be specially designed, connected to the rail vehicle, and approved, etc.
[0010] To determine the first pulses and the second pulses, functional relationships from beam theory can be used, for example, whereby the forces causing the first bending deformations and the second bending deformations can be determined from the first bending deformations and the second bending deformations, and the forces can be multiplied by an action duration of the forces to obtain the first pulses and the second pulses. To record the first bending deformations and the second bending deformations, the first sensor and the second sensor can be designed, for example, as strain-voltage converters (e.g. as a strain gauge or as a piezoelectric measuring transducer, etc.).
[0011] The first pulse direction and the second pulse direction can be aligned in the same direction or in opposite directions. Forming the first pulse absolute values and the second pulse absolute values is advantageous because it allows the first pulse and the second pulse to be recorded as representing a derailment even if the first pulse and the second pulse have opposite directions.
[0012] If the sums are calculated from the first absolute pulse values and the second absolute pulse values and the sums are compared with the pulse threshold, this ensures a reliable response of the derailment detection system. This makes it possible, for example, for the derailment to be detected even if the first absolute pulse values are very large and the second absolute pulse values are very small (for example, due to a fault in the second sensor), provided the sums are equal to or greater than the pulse threshold, etc.
[0013] Further advantageous embodiments of the method according to the invention emerge from the subclaims.
[0014] For example, it is advantageous if the pulse threshold value depends on the speed of the rail vehicle.
[0015] This allows for the speed dependence of the first and second pulses to be taken into account when mechanical contact is established between the obstacle contact bar and the track bed, whereby, for example, a high travel speed leads to a large first pulse and a large second pulse. This reduces the risk of false triggering of the derailment detection system.
[0016] It can also be helpful if the pulse threshold value is formed from a linear first relationship between a first gradient, which is a pulse normalized to the driving speed and which is multiplied by the driving speed, and a basic pulse, which is a first y-axis intercept and is added to a first product of the first gradient and the driving speed.
[0017] By means of this measure, the pulse threshold value can be made to increase, for example, with increasing driving speed, whereby the basic pulse can define a first trigger threshold which must be reached or exceeded by the first pulses and / or the second pulses even at a driving speed of 0 km / h in order for the derailment detection to be triggered.
[0018] A preferred solution is obtained if signals representing the first bending deformations and the second bending deformations, which are transmitted from the first sensor and the second sensor to the evaluation unit, are low-pass filtered, wherein by means of the evaluation unit, first forces with a first force acting direction parallel to the direction of travel are determined from the first bending deformations represented by the low-pass filtered signals and second forces with a second force acting direction parallel to the direction of travel are determined from the second bending deformations represented by the low-pass filtered signals, wherein first absolute force values are formed from the first forces and second absolute force values are formed from the second forces, wherein as a second criterion for detecting the derailment of the rail vehicle, the first absolute force values and the second absolute force values are compared with a force threshold value, whereby it is checked,whether the second criterion is met, wherein the second criterion is met when the first absolute force values and / or the second absolute force values are equal to or greater than the force threshold, wherein only those forces which occur at a frequency equal to or lower than a defined limit frequency are taken into account as first forces and as second forces in the second criterion, and wherein the derailment of the rail vehicle is detected when the first criterion and / or the second criterion is / are met. As a result, the behavior of an arrangement comprising the obstacle contact bar, the first holding element and the second holding element is taken into account in the method, according to which vibrations of this arrangement decrease in frequency when the obstacle contact bar makes mechanical contact with the track bed. This behavior leads to signals,which represent the forces due to the first bending deformations and the second bending deformations during a mechanical contact between the obstacle contact bar and the track body, with a characteristic frequency spectrum that can be evaluated with regard to derailment detection.
[0019] With a view to reducing risks in connection with a false triggering of the derailment detection, it may be advantageous if the second criterion is only fulfilled when, for a defined first majority of the determined first forces and / or for a defined second majority of the determined second forces, the first absolute force amounts and / or the second absolute force amounts are equal to the force threshold value or greater than the force threshold value.
[0020] A speed-dependent triggering of the
[0021] Derailment detection with a contact force-based
[0022] Evaluation of the signals is possible if the force threshold value depends on the driving speed of the rail vehicle.
[0023] In connection with a speed-dependent triggerability of the derailment detection in the contact force-based evaluation of the signals, it can be helpful if the force threshold value is formed from a linear second relationship between a second gradient, which is a force normalized to the driving speed and which is multiplied by the driving speed, and a basic force, which is a second y-axis intercept and is added to a second product of the second gradient and the driving speed.
[0024] By means of this measure, the force threshold value can be made to increase, for example, with increasing driving speed, whereby the basic force can define a second triggering threshold which must be reached or exceeded by the first forces and / or the second forces even at a driving speed of 0 km / h in order for the derailment detection to be triggered.
[0025] An implementation of the cutoff frequency in a low-pass filter that is matched to the arrangement of the obstacle contact bar, the first holding element and the second holding element is achieved when the cutoff frequency is a cutoff frequency of the low-pass filter, wherein the cutoff frequency is smaller than a natural frequency of an oscillatory system comprising the first holding element, the second holding element and the obstacle contact bar.
[0026] The low-pass filter can, for example, be implemented in the evaluation unit.
[0027] A high degree of plausibility and reliability of derailment detection is achieved when the cutoff frequency of the low-pass filter is 20 Hz. A trigger criterion for derailment detection by means of an evaluation of non-low-pass filtered contact forces is established when, before low-pass filtering of the signals representing the first bending deformations and the second bending deformations, third forces and fourth forces are determined from the signals, whereby the evaluation unit determines the third forces with the first force acting direction parallel to the direction of travel from the first bending deformations represented by the unfiltered signals and the fourth forces with the second force acting direction parallel to the direction of travel from the second bending deformations represented by the unfiltered signals, whereby third force absolute values are formed from the third forces and fourth force absolute values are formed from the fourth forces.wherein, as a third criterion for detecting the derailment of the rail vehicle, the third absolute force values and the fourth absolute force values are compared with a basic force threshold value which is smaller than the force threshold value, thereby checking whether the third criterion is met, wherein the third criterion is met when the third absolute force values and / or the fourth absolute force values are equal to or greater than the basic force threshold value, and wherein the derailment of the rail vehicle is detected when the second criterion is met together with the third criterion and / or the first criterion.
[0028] This measure allows, for example, high-frequency signals (e.g., frequencies in the range of 400 Hz), from which contact forces are determined, to be taken into account in the evaluation. Consideration of the third and fourth forces further improves the plausibility of derailment detection results.
[0029] For a combination of derailment detection with a
[0030] Obstacle detection can be advantageous if the third
[0031] Forces and the fourth forces are integrated over time between defined temporal integration limits, and the corresponding integration results from the integration of the third forces and the fourth forces are each divided by the speed of the rail vehicle. This measure allows the mass of a collision object to be determined.
[0032] A further advantageous solution is achieved by detecting a derailment in a speed range from 0 km / h up to the maximum speed of the rail vehicle. This measure can, for example, prevent the derailment from occurring at a low speed and going unnoticed. For example, it can prevent the derailed rail vehicle from starting from a standstill.
[0033] A promising field of application can be developed with a device for derailment detection for rail vehicles, configured to carry out the method according to the invention, comprising a first holding element, a second holding element and an obstacle contact bar, wherein undersides of the first holding element and of the second holding element are connected to the obstacle contact bar and upper sides of the first holding element and of the second holding element are connectable to a running gear of the rail vehicle in front of a wheelset of a rail vehicle, so that in the event of a derailment of the rail vehicle, a mechanical contact is formed between the obstacle contact bar and a track body for the rail vehicle, whereby first bending deformations of the first holding element and second bending deformations of the second holding element are formed, further comprising a first sensor for detecting the first bending deformations,a second sensor for detecting the second bending deformations and an evaluation unit, wherein the first sensor is connected to the first holding element and the second sensor is connected to the second holding element, wherein the first sensor and the second sensor are connected to the evaluation unit in a signal-transmitting manner, wherein the evaluation unit is configured to determine first pulses with a first pulse effective direction parallel to a direction of travel of the rail vehicle from the first bending deformations and second pulses with a second pulse effective direction parallel to the direction of travel from the second bending deformations, to form first pulse absolute values from the first pulses and second pulse absolute values from the second pulses,as a first criterion for detecting the derailment of the rail vehicle, to compare the first pulse absolute values and the second pulse absolute values on the one hand or sums of the first pulse absolute values and the second pulse absolute values on the other hand with a pulse threshold value, and to check whether the first criterion is met, whereby the first criterion is met if the first pulse absolute values and / or the second pulse absolute values on the one hand or the sums on the other hand are equal to or greater than the pulse threshold value.
[0034] With such a device it is possible, for example, to carry out combined derailment detection and obstacle detection.
[0035] For example, a low-pass filter for low-pass filtering of signals can be implemented in the evaluation unit.
[0036] A particularly robust design of the device is obtained if a contact layer or a contact element made of a shock-resistant and abrasion-resistant material is arranged at least on the underside of the obstacle contact bar.
[0037] A high level of operational reliability is achieved with a rail vehicle having at least one derailment detection device according to the invention. The invention is explained in more detail below using exemplary embodiments.
[0038] Examples include:
[0039] Fig. 1: A flowchart of an exemplary
[0040] Embodiment variant of a method according to the invention for derailment detection, and Fig. 2: An exemplary embodiment variant of a rail vehicle according to the invention with an exemplary embodiment variant of a device according to the invention for
[0041] Derailment detection as diagonal crack.
[0042] Fig. 1 shows a flow chart for an exemplary embodiment of a method according to the invention for derailment detection for rail vehicles. By means of a first sensor 1, shown as an example in Fig. 2, which is connected to a first holding element 3, shown as an example in Fig. 2, first bending deformations of the first holding element 3 are detected. By means of a second sensor 2, also shown as an example in Fig. 2, which is connected to a second holding element 4, shown as an example in Fig. 2, second bending deformations of the second holding element 4 are detected (measurement step 5).
[0043] The first holding element 3 and the second holding element 4 are connected to an obstacle contact bar 6, shown by way of example in Fig. 2, which is held by means of the first holding element 3 and the second holding element 4 in front of a wheelset 7 of a rail vehicle shown by way of example in Fig. 2 on a chassis frame 8 of a chassis 9 of the rail vehicle and which, in the event of a derailment of the rail vehicle, forms a mechanical contact with a conductor rail 10 of a track body for the rail vehicle, shown by way of example in Fig. 2, whereby the first bending deformations and the second bending deformations are formed.
[0044] The first sensor 1 and the second sensor 2, which are designed as strain gauges, are connected in a signal-transmitting manner to an evaluation unit 11, shown as an example in Fig. 2, which is arranged in the rail vehicle.
[0045] On the basis of measuring step 5, a pulse evaluation step 12 is then carried out. For this purpose, the evaluation unit 11 is used to determine first pulses with a first pulse effective direction parallel to a direction of travel of the rail vehicle (parallel to the conductor rail 10) from the first bending deformations, and second pulses with a second pulse effective direction parallel to the direction of travel are determined from the second bending deformations. To determine the first bending deformation and the second bending deformation, the first sensor 1 and the second sensor 2 are each formed from four strain gauges, which are arranged on the front and back sides of the first holding element 3 and the second holding element 4, have parallel grids (0 ° - 0 " arrangement), and are connected to form a Wheatstone bridge circuit.Using a bridge equation, strains are determined from the resistances of the first sensor 1 and the second sensor 2 in the evaluation unit 11, which strains correlate with the first bending deformations and the second bending deformations.
[0046] Using a relationship between a mechanical stress on the one hand and a bending moment and a section modulus on the other hand and using Hooke's law, bending moments are determined from the determined strains, elastic moduli of the first holding element 3 and the second holding element 4 as well as section moduli of the first holding element 3 and the second holding element 4.
[0047] From a first distance between the first sensor 1 and a lower edge of the obstacle contact bar 6 and from first bending moments with respect to the first holding element 3, which are determined from first strains of the first sensor 1 that correlate with the first bending deformations, horizontal first contact forces between the obstacle contact bar 6 and the conductor rail 10 are determined. From a second distance between the second sensor 2 and the lower edge of the obstacle contact bar 6 and from second bending moments with respect to the second holding element 4, which are determined from second strains of the second sensor 2 that correlate with the second bending deformations, horizontal second contact forces between the obstacle contact bar 6 and the conductor rail 10 are determined. The first contact forces are multiplied by first effective durations of the first contact forces, whereby the first pulses are determined.
[0048] The second contact forces are multiplied by the second durations of the second contact forces, thereby determining the second impulses.
[0049] First pulse absolute values are formed from the first pulses and second pulse absolute values are formed from the second pulses, whereby as a first criterion for detecting the derailment of the rail vehicle, sums of the first pulse absolute values and the second pulse absolute values are compared with a pulse threshold value, whereby it is checked whether the first criterion is met, whereby the first criterion is met if the sums are equal to the pulse threshold value or greater than the pulse threshold value.
[0050] According to the invention, it is also conceivable that the first pulse absolute amounts and the second pulse absolute amounts are individually compared with the pulse threshold value and the first criterion is met when the first pulse absolute amounts and / or the second pulse absolute amounts are equal to the pulse threshold value or greater than the pulse threshold value.
[0051] The pulse threshold value depends on a travel speed of the rail vehicle and is formed from a linear first relationship between a first gradient, which is a pulse normalized to the travel speed and which is multiplied by the travel speed, and a base pulse, which is a first y-axis intercept and is added to a first product of the first gradient and the travel speed.
[0052] In addition to the impulse evaluation step 12, a first force evaluation step 13 is also carried out in the method. Here, signals representing the first bending deformations and the second bending deformations, which are transmitted from the first sensor 1 and the second sensor 2 to the evaluation unit 11, are low-pass filtered by means of a low-pass filter 15. By means of the evaluation unit 11, first forces with a first force acting direction parallel to the direction of travel are determined from the first bending deformations represented by the low-pass filtered signals, and second forces with a second force acting direction parallel to the direction of travel are determined from the second bending deformations represented by the low-pass filtered signals. The first forces and the second forces are determined as described above in connection with the first contact forces and the second contact forces.The first forces and the second forces are also horizontal contact forces between the obstacle contact bar 6 and the conductor rail 10.
[0053] First absolute force values are formed from the first forces and second absolute force values are formed from the second forces, wherein as a second criterion for detecting the derailment of the rail vehicle the first absolute force values and the second absolute force values are compared with a force threshold value, whereby it is checked whether the second criterion is met, wherein the second criterion is met if, for a defined first plurality of the determined first forces and for a defined second plurality of the determined second forces, the first absolute force values and the second absolute force values are equal to the force threshold value or greater than the force threshold value.
[0054] In the second criterion of the first force evaluation step 13, only those forces are considered as first forces and as second forces that occur at a frequency equal to or lower than a defined cutoff frequency. The cutoff frequency is a cutoff frequency of the low-pass filter 15 implemented in the evaluation unit 11 and lower than a natural frequency of an oscillatory system comprising the first holding element 3, the second holding element 4, and the obstacle contact bar 6. The cutoff frequency of the low-pass filter 15 is 20 Hz.
[0055] According to the invention, it is also conceivable that the second criterion is fulfilled when individual first absolute force amounts and / or individual second absolute force amounts are equal to the force threshold value or greater than the force threshold value.
[0056] According to the invention, it is further possible that the second criterion is fulfilled when the first absolute force values of the defined first plurality or the second absolute force values of the defined second plurality are equal to the force threshold value or greater than the force threshold value.
[0057] The force threshold depends on the driving speed of the rail vehicle and is formed from a linear second relationship between a second gradient, which is a force normalized to the driving speed and which is multiplied by the driving speed, and a basic force, which is a second y-axis intercept and is added to a second product of the second gradient and the driving speed.
[0058] In a second force evaluation step 14, before low-pass filtering of the signals, third forces and fourth forces are determined from the signals, as described above in connection with the first contact forces and the second contact forces, representing the first bending deformations and the second bending deformations. These are horizontal contact forces between the obstacle contact bar 6 and the conductor rail 10. By means of the evaluation unit 11, the third forces with the first force acting direction parallel to the direction of travel are determined from the first bending deformations represented by the unfiltered signals, and the fourth forces with the second force acting direction parallel to the direction of travel are determined from the second bending deformations represented by the unfiltered signals. Third force absolute values are formed from the third forces, and fourth force absolute values are formed from the fourth forces.
[0059] As a third criterion for detecting the derailment of the rail vehicle, the third absolute force values and the fourth absolute force values are compared with a basic force threshold value which is smaller than the force threshold value, thereby checking whether the third criterion is met.
[0060] The third criterion is met if the third absolute force values and the fourth absolute force values are equal to or greater than the basic force threshold.
[0061] According to the invention, it is also conceivable that the third criterion is fulfilled when the third absolute force values or the fourth absolute force values are equal to the basic force threshold value or greater than the basic force threshold value.
[0062] The derailment of the rail vehicle is then detected in a detection step 16 if the second criterion is met together with the third criterion or the first criterion.
[0063] However, according to the invention it is also possible that the derailment is only detected, for example, when the second criterion together with the third criterion and the first criterion are met.
[0064] According to the invention, it is further conceivable that the derailment is detected, for example, when the first criterion and / or the second criterion is / are met and the third criterion is omitted, etc.
[0065] If the derailment is detected, the evaluation unit 11 intervenes in a safety loop of the rail vehicle, which triggers an emergency braking of the rail vehicle (brake triggering step 17).
[0066] Derailment detection according to the method described in connection with Fig. 1 is carried out in a first travel speed range from 0 km / h up to a maximum speed of the rail vehicle. This is a favorable solution. However, according to the invention, it is also possible, for example, to define a smaller, second travel speed range within the first travel speed range and to activate derailment detection only when the rail vehicle is traveling at a speed within the second travel speed range.
[0067] In addition to derailment detection, the method also detects obstacles using a mass evaluation step 18. For this purpose, the third forces and the fourth forces are integrated over time between defined temporal integration limits. The corresponding integration results from the integration of the third forces and the fourth forces are each divided by the speed of the rail vehicle, thereby determining the masses. If the masses exceed a defined mass threshold, a safety-critical collision of an object with the obstacle contact beam 6 is assumed, and the brake triggering step 17 is carried out.
[0068] In Fig. 2, an exemplary embodiment of a rail vehicle according to the invention with an exemplary embodiment of a device according to the invention for derailment detection is shown as an oblique view.
[0069] The device comprises a first holding element 3, a second holding element 4 and an obstacle contact bar 6, wherein undersides of the first holding element 3 and of the second holding element 4 are connected to the obstacle contact bar 6 and upper sides of the first holding element 3 and of the second holding element 4 are connected in front of a wheelset 7 of the rail vehicle to a chassis frame 8 of a chassis 9 of the rail vehicle.
[0070] The obstacle contact bar 6 is arranged transversely to a track 19 of a track bed for the rail vehicle above a conductor rail 10 of the track bed. In the event of a derailment of the rail vehicle, mechanical contact is formed between the obstacle contact bar 6 and the conductor rail 10, causing first bending deformations of the first holding element 3 and second bending deformations of the second holding element 4.
[0071] The device further comprises a first sensor 1 for detecting the first bending deformations, a second sensor 2 for detecting the second bending deformations and an evaluation unit 11, wherein the first sensor 1 is connected to the first holding element 3 and the second sensor 2 is connected to the second holding element 4. The first sensor 1 is connected to the evaluation unit 11 via a first cable 20 in a signal-transmitting manner. The second sensor 2 is connected to the evaluation unit 11 via a second cable 21 in a signal-transmitting manner. According to the invention, it is also conceivable for the first sensor 1 and the second sensor 2 to be connected to the evaluation unit 11 in a signal-transmitting manner via radio.
[0072] The evaluation unit 11 is arranged in a car body 22 of the rail vehicle and is designed as an on-board computer with a processor, a memory, computer program products and connections.
[0073] A strip-shaped contact element 23 made of a shock-resistant and friction-resistant material is arranged on the underside of the obstacle contact bar 6. The contact element 23 is made of hardened steel to ensure mechanical contact between the contact element 23 and the conductor rail 10 in a derailment scenario.
[0074] The device is configured to carry out the method described by way of example in connection with Fig. 1. A measuring step 5 is carried out by means of the first sensor 1 and the second sensor 2, and an impulse evaluation step 12, a first force evaluation step 13, a second force evaluation step 14, a detection step 16, a mass evaluation step 18 and, if necessary, a brake triggering step 17 are carried out by means of the evaluation unit 11.
[0075] To carry out the first force evaluation step 13, a low-pass filter 15 is implemented in the evaluation unit 11. The measuring step 5, the impulse evaluation step 12, the first force evaluation step 13, the second force evaluation step 14, the detection step 16, the mass evaluation step 18, and the brake triggering step 17 are described by way of example in connection with Fig. 1.
[0076] List of names
[0077] 1 First sensor
[0078] 2 Second sensor
[0079] 3 First holding element
[0080] 4 Second holding element
[0081] 5 measuring steps
[0082] 6 obstacle contact bars
[0083] 7 wheelset
[0084] 8 chassis frames
[0085] 9 Chassis
[0086] 10 Busbar
[0087] 11 Evaluation unit
[0088] 12 Impulse evaluation step
[0089] 13 First force assessment step
[0090] 14 Second force assessment step
[0091] 15 low-pass filters
[0092] 16 Detection step
[0093] 17 Brake release step
[0094] 18 Mass evaluation step
[0095] 19 track
[0096] 20 First cable
[0097] 21 Second cable
[0098] 22 car body
[0099] 23 Contact element
Claims
Patent claims 1. A method for derailment detection for rail vehicles, wherein first bending deformations of the first holding element (3) are detected by means of a first sensor (1) connected to a first holding element (3), and second bending deformations of the second holding element (4) are detected by means of a second sensor (2) connected to a second holding element (4), wherein the first holding element (3) and the second holding element (4) are connected to an obstacle contact bar (6) which is held by means of the first holding element (3) and the second holding element (4) in front of a wheelset (7) of a rail vehicle on a running gear (9) of the rail vehicle and which, in the event of a derailment of the rail vehicle, forms mechanical contact with a track body for the rail vehicle, whereby the first bending deformations and the second bending deformations are formed,and wherein the first sensor (1) and the second sensor (2) are connected to an evaluation unit (11) for signal transmission, characterized in that by means of the evaluation unit (11), first pulses with a first pulse effective direction parallel to a direction of travel of the rail vehicle are determined from the first bending deformations and second pulses with a second pulse effective direction parallel to the direction of travel are determined from the second bending deformations, wherein first pulse absolute values are formed from the first pulses and second pulse absolute values are formed from the second pulses, wherein as a first criterion for detecting the derailment of the rail vehicle, the first pulse absolute values and the second pulse absolute values on the one hand or sums of the first pulse absolute values and the second pulse absolute values on the other hand are compared with a pulse threshold value, whereby it is checked whether the first criterion is met,where the first criterion is fulfilled if the first impulse absolute values and / or the, second pulse absolute values on the one hand or the sums on the other hand are equal to the pulse threshold value or greater than the pulse threshold value.
2. Method according to claim 1, characterized in that the pulse threshold value is dependent on a driving speed of the rail vehicle.
3. Method according to claim 2, characterized in that the pulse threshold value is formed from a linear first relationship between a first gradient, which is a pulse normalized to the driving speed and which is multiplied by the driving speed, and a basic pulse, which is a first y-axis section and is added to a first product of the first gradient and the driving speed.
4. Method according to one of claims 1 to 3, characterized in that signals representing the first bending deformations and the second bending deformations, which are transmitted from the first sensor (1) and the second sensor (2) to the evaluation unit (11), are low-pass filtered, wherein by means of the evaluation unit (11) first forces with a first force acting direction parallel to the direction of travel are determined from the first bending deformations represented by the low-pass filtered signals and second forces with a second force acting direction parallel to the direction of travel are determined from the second bending deformations represented by the low-pass filtered signals, wherein first force absolute values are formed from the first forces and second force absolute values are formed from the second forces,wherein, as a second criterion for detecting the derailment of the rail vehicle, the first absolute force values and the second absolute force values are compared with a force threshold value, thereby checking whether the second criterion is met, wherein the second criterion is met if the first absolute force values and / or, the second absolute values of the force are equal to or greater than the force threshold, wherein only those forces which occur with a frequency equal to or less than a defined limit frequency are taken into account as first forces and as second forces in the second criterion, and wherein the derailment of the rail vehicle is detected when the first criterion and / or the second criterion is / are met.
5. The method according to claim 4, characterized in that the second criterion is only met when, for a defined first plurality of the determined first forces and / or for a defined second plurality of the determined second forces, the first absolute force amounts and / or the second absolute force amounts are equal to the force threshold value or greater than the force threshold value.
6. Method according to claim 4 or 5, characterized in that the force threshold value is dependent on a driving speed of the rail vehicle.
7. Method according to claim 6, characterized in that the force threshold value is formed from a linear second relationship between a second gradient, which is a force normalized to the driving speed and which is multiplied by the driving speed, and a basic force, which is a second y-axis intercept and is added to a second product of the second gradient and the driving speed. 8 . Method according to one of claims 4 to 7 , characterized in that the cutoff frequency is a cutoff frequency of a low-pass filter ( 15 ), the cutoff frequency being smaller than a natural frequency of an oscillatory system comprising the first holding element ( 3 ), the second holding element ( 4 ) and the obstacle contact bar ( 6 ).
9. Method according to claim 8, characterized in that the cutoff frequency of the low-pass filter (15) is 20 Hz.
10. Method according to one of claims 4 to 9, characterized in that before low-pass filtering of the signals representing the first bending deformations and the second bending deformations, third forces and fourth forces are determined from the signals, wherein by means of the evaluation unit (11) the third forces with the first force acting direction parallel to the direction of travel are determined from the first bending deformations represented by the unfiltered signals and the fourth forces with the second force acting direction parallel to the direction of travel are determined from the second bending deformations represented by the unfiltered signals, wherein third force absolute values are formed from the third forces and fourth force absolute values are formed from the fourth forces, wherein as a third criterion for detecting the derailment of the rail vehicle, the third force absolute values and the fourth force absolute values are combined with a basic force threshold value,which is smaller than the force threshold, thereby checking whether the third criterion is met, wherein the third criterion is met when the third absolute force values and / or the fourth absolute force values are equal to or greater than the basic force threshold, and wherein the derailment of the rail vehicle is detected when the second criterion is met together with the third criterion and / or the first criterion.
11. Method according to claim 10, characterized in that the third forces and the fourth forces are integrated over time between defined temporal integration limits and corresponding integration results from the integration of the third forces and the fourth forces are each divided by a travel speed of the rail vehicle.
12. Method according to one of claims 1 to 11, characterized in that derailment detection is carried out in a driving speed value range from 0 km / h up to a maximum speed of the rail vehicle.
13. A device for derailment detection for rail vehicles, configured to carry out the method according to at least one of claims 1 to 12, comprising a first holding element (3), a second holding element (4), and an obstacle contact bar (6), wherein undersides of the first holding element (3) and the second holding element (4) are connected to the obstacle contact bar (6), and upper sides of the first holding element (3) and the second holding element (4) are connectable to a running gear (9) of the rail vehicle in front of a wheelset (7) of a rail vehicle, such that, in the event of a derailment of the rail vehicle, mechanical contact is formed between the obstacle contact bar (6) and a track body for the rail vehicle, whereby first bending deformations of the first holding element (3) and second bending deformations of the second holding element (4) are formed,further comprising a first sensor (1) for detecting the first bending deformations, a second sensor (2) for detecting the second bending deformations and an evaluation unit (11), wherein the first sensor (1) is connected to the first holding element (3) and the second sensor (2) is connected to the second holding element (4), wherein the first sensor (1) and the second sensor (2) are connected to the evaluation unit (11) in a signal-transmitting manner, characterized in that the evaluation unit (11) is configured to determine first pulses with a first pulse effective direction parallel to a direction of travel of the rail vehicle from the first bending deformations and second pulses with a second pulse effective direction parallel to the direction of travel from the second bending deformations, to form first pulse absolute values from the first pulses and second pulse absolute values from the second pulses, as, The first criterion for detecting the derailment of the rail vehicle is to compare the first absolute pulse values and the second absolute pulse values on the one hand or sums of the first absolute pulse values and the second absolute pulse values on the other hand with a pulse threshold value and to check whether the first criterion is met, whereby the first criterion is met if the first absolute pulse values and / or the second absolute pulse values on the one hand or the sums on the other hand are equal to or greater than the pulse threshold value.
14. Device according to claim 13, characterized in that a contact layer or a contact element (23) made of an impact-resistant and abrasion-resistant material is arranged at least on a beam underside of the obstacle contact beam (6).
15. Rail vehicle with at least one device according to claim 13 or 14.