Method and system for determining a disturbance torque acting on a wheelset axle of a rail vehicle, and rail vehicle

Abstract

The invention relates to a method for determining a disturbance torque (MStör_a, MStör_b), in particular a torsion torque of a torsional vibration (13), acting on a wheelset axle (2) of a rail vehicle (27), comprising the following steps: detecting a rotational movement (6a, 6b) of the wheelset axle (1) using at least one sensor (5a, 5b), preferably on the wheelset axle (2); and determining the disturbance torque (MStör_a, MStör_b), preferably an amplitude (A_a, A_b) of the disturbance torque (MStör_a, MStör_b), from the rotational movement (6a, 6b) using a conversion factor (U). The invention also relates to a system (51) for determining a disturbance torque (MStör_a, MStör_b) acting on a wheelset axle (2) of a wheelset (1), as well as a rail vehicle (27) with a system (51) of this type.

Description

[0001]Description Method and system for determining a disturbance torque acting on a wheelset axle of a rail vehicle, and rail vehicle Technical field The invention relates to a method for determining a disturbance torque acting on a wheelset axle of a rail vehicle, in particular a torsional moment of a rolling vibration, and to a method for controlling and / or regulating a rail vehicle. Furthermore, the invention relates to a system for determining a disturbance torque acting on a wheelset axle of a rail vehicle, in particular a torsional moment of a rolling vibration, and to a rail vehicle with such a system. State of the art During operation of rail vehicles, forces and torques can occur at the wheel sets that cause undesired movements and restrict the operation of the rail vehicle or even lead to damage or wear.An example of such undesirable movements is rolling vibration, which occurs directly on the wheelsets and leads to torsion of the affected wheelset axles. The resulting torsional moments can be very high and, if no countermeasures are taken, exceed 100 kNm, which can lead to heavy loads on the affected wheelset and increased wear. The frequency of rolling vibration depends in particular on the geometry and mass distribution of the wheelset in question, taking into account the wheels, gears and brake discs, etc., and is usually in the range between 60 Hz and 150 Hz. Since the build-up times of rolling vibration are generally very short, often less than 500 ms, it is difficult to detect this type of wheelset movement at an early stage. This is, however, essential in order to initiate appropriate countermeasures in a timely manner and to avoid increased wear and damage to the wheelset.Rolling vibrations can occur, among other things, when a rail vehicle starts or brakes. One countermeasure to prevent these unwanted movements is, for example, reducing the acceleration of the rail vehicle during start-up, which, however, restricts its operation. It is known from the prior art to detect the occurrence of rolling vibrations using sensors. EP 3064793 A1 discloses a motion sensor system for rail vehicles that has several rotary motion sensors and enables detection of rolling vibrations. An incremental encoder can be configured to output a rolling signal. However, the sensor system of EP 3064793 A1 does not allow the torsional moments of the detected rolling vibration to be determined.Thus, although a rolling vibration can be detected as such and countermeasures initiated, the countermeasure taken cannot be adapted to the magnitude of the torsional moments occurring. If the torsional moments occurring on a wheelset are very large, it may be necessary to take further countermeasures immediately to avoid damage to the rail vehicle. If, on the other hand, the torsional moments are very small, no countermeasures at all or only mild countermeasures that barely restrict the operation of the rail vehicle, such as a only slight reduction in acceleration, may be necessary. Unfortunately, with the motion sensor system of EP 3064793 A1, due to a lack of knowledge about the magnitude of the torsional moments, it is not possible to decide which countermeasures need to be taken to suppress rolling vibrations without restricting the operation of the rail vehicle more than necessary.In light of these statements, it would therefore be desirable to be able to determine the magnitude of the torsional moments of rolling vibrations in order to be able to take appropriate countermeasures in the event of 3 / 31 rolling vibrations. Furthermore, it is known from the prior art to generally use strain gauges to measure torques. However, applying strain gauges to rail vehicle wheelsets is complex, and the measurement results are prone to errors after extended periods of operation. Furthermore, the strain gauges can become detached during operation. The strain gauges would therefore have to be checked regularly, which represents an additional expense. Another disadvantage is that the strain gauges on the rotating wheelset shaft must be supplied with power, and the measured data must be transmitted from the strain gauges to a processing unit, which entails a high level of design and technical complexity.Description of the invention It is therefore an object of the present invention to alleviate the disadvantages of the prior art or even to eliminate them entirely. Preferably, the object of the present invention is to provide a method and a system with which a disturbance torque acting on a wheelset shaft of a rail vehicle, in particular a torsional moment of a rolling vibration, can be determined. This object is achieved by a method according to claim 1 and by a system according to claim 11. The method according to claim 1 can be used in a method for controlling and / or regulating a rail vehicle according to claim 10. The system according to claim 11 can be used in a rail vehicle according to claim 12.The method according to claim 1 comprises the following steps: detecting a rotational movement of the wheelset shaft by at least one sensor, preferably on the wheelset shaft; and determining the disturbance torque, preferably an amplitude of the disturbance torque, from the rotational movement using a conversion factor. 22021 4 / 31 The invention is based on the finding that there is a relationship between the rotational movement of the wheelset shaft and the occurring disturbance torque, which relationship can be expressed using a conversion factor. Based on the knowledge of the rotational movement of the wheelset shaft, the disturbance torque, in particular a magnitude of the disturbance torque, on the wheelset shaft can thus be determined without having to perform a direct and comparatively complex torque measurement.The advantage of the invention is therefore that the disturbance torque can be determined via the rotational movement of the wheelset shaft, which is technically easier to detect, for example via the angular position or angular velocity of the wheelset shaft. The rotational movement of the wheelset shaft can be detected using at least one sensor, which is preferably arranged on the wheelset shaft. The sensor can, for example, detect the position, in particular the angular position, and / or the speed, in particular the angular velocity, and / or the acceleration, in particular the angular acceleration, of the wheelset shaft directly or indirectly as a rotational movement. The rotational movement can be formed by a temporal profile of the (angular) position, the (angular) velocity and / or the (angular) acceleration.Since the (angular) position, (angular) velocity, and (angular) acceleration are linked via the time derivative, a conversion between the variables can also be performed using time derivative or time integration. The rotational movement can be recorded and displayed as a continuous or discrete time profile. The time profile includes a direct or indirect change in the position, in particular the angular position, of the wheelset shaft. In one embodiment of the invention, the sensor can be designed as an incremental encoder. The incremental encoder can record the angular position and / or its change of the wheelset shaft and derive the angular velocity and, if applicable, also the angular acceleration from this.In general, the sensor can have a stationary sensor part and a sensor part that is movable relative to the stationary sensor part and is mounted on the wheelset axle or on an element connected to it in a rotationally fixed manner. The movable sensor part, which can also be referred to as the sensor rotor, can follow the rotation of the wheelset axle. The movement of the rotor can be detected by the stationary sensor part, which can also be referred to as the sensor head. The sensor head can be attached to a frame or chassis of the rail vehicle. The sensor rotor can, for example, be a ring provided with spaced-apart codes along its circumference. The codes can, for example, be magnetic or optical markings.The coding of the ring can be detected by the sensor head, for example, in the case of magnetic markings by a magnetic detection unit, preferably a coil, or in the case of optical markings by an optical detection unit, preferably an optical sensor element. The sensor is preferably spaced from the center of the wheelset axle in the longitudinal direction of the wheelset axle because this is typically where a nodal point for the rolling vibration is located and therefore rolling vibrations cannot be detected in the center of the wheelset axle. It is therefore advantageous if the sensor is arranged in an end region of the wheelset axle, in particular at one end of the wheelset axle, because this is where the torsion of the wheelset axle is greatest. The disturbance torque can be determined using the conversion factor and the detected rotational movement.The conversion factor links the rotational movement, in particular an angular velocity or a related variable, such as an angular position or angular acceleration, with the disturbance torque. It is preferred if only a limited frequency interval of the rotational movement, in which rolling vibrations typically occur, is used to determine the disturbance torque. Such a frequency interval can, for example, be between 60 Hz and 150 Hz or between 80 Hz and 140 Hz. In this way, movement components that are not related to the rolling vibration can be filtered out of the detected rotational movement. The first 22021 6 / 31 eigenmode of torsion due to rolling vibration has a (natural) frequency in the specified frequency intervals for typical wheelsets.Preferably, at least the torsional moment of the first eigenmode of torsion of the wheelset axle or wheelset is detected as the disturbance torque. Furthermore, rolling vibrations can be detected using only a single sensor because a rotational movement in this frequency range is present. By using two sensors, particularly at opposite end regions of the wheelset axle, rolling vibrations can be clearly detected and incorrect determinations can be avoided because the end regions of the wheelset axle are twisted in different directions by the torsional movement. However, the method also works when using a single sensor. By using two sensors, incorrect detections of rolling vibrations can be avoided. The conversion factor can be a real number and specifies a relationship between the rotational movement of the wheelset axle and the disturbance torque.In a preferred embodiment, the conversion factor specifies a relationship between the angular velocity of the wheelset axle and the disturbance torque, in particular the torsional moment of a rolling vibration. In this case, the conversion factor has the unit Nm / (rad / s). Since, as explained above, a mathematical relationship exists between the (angular) position, the (angular) velocity, and the (angular) acceleration, the conversion factor can also establish a relationship between one of the other variables mentioned (or an even higher time derivative) and the disturbance torque. If two sensors are used on the wheelset axle, the disturbance torque can also be determined based on a difference between the rotational movements detected by the sensors. For example, a difference between the angular positions detected by the sensors can be determined, and the disturbance torque can be determined on this basis.In this case, the conversion factor can be determined based on the torsional spring stiffness or be formed by it. Using the conversion factor, a temporal progression of the disturbance torque can be determined from a temporal progression of the rotational movement 22021 7 / 31. The value of the conversion factor depends, among other things, on the geometry of the wheelset, the material of the wheelset and the mass distribution of the wheelset. A wheelset of a rail vehicle can have a wheelset axle, at least two wheels and, if necessary, at least one gear. The conversion factor can be a fixed or a time-varying variable. If the conversion factor is a variable, it can be adapted to a changed mass distribution and geometry of the wheelset in order to take into account any wear on the wheelset.In this way, the disturbance torque can be determined with high accuracy over the service life of the wheelset. The conversion factor can be linked to the rotational movement, in particular multiplied, in order to obtain the disturbance torque. In a preferred embodiment of the invention, the rotational movement is represented by an angular position, an angular velocity, an angular acceleration of the wheelset shaft or a related, preferably proportional, variable. The conversion factor has the unit Nm / (rad / s), for example, if the rotational movement is detected as angular velocity. For an exemplary wheelset, the conversion factor can be between 25,000 Nm / (rad / s) and 30,000 Nm / (rad / s) if the rotational movement is detected as angular velocity. The angular velocity or the other variables can be measured directly or indirectly by the sensor.For example, the angular position of the wheelset axle can be measured, and the angular velocity or angular acceleration can be determined by time-based differentiation. In another example, the sensor can measure the change in the angular position of the wheelset axle and output the angular velocity or angular acceleration. Alternatively, the sensor can also measure the angular acceleration, and the angular velocity or angular position can be determined by time-based integration of the angular acceleration. The angular position, angular velocity, or angular acceleration can be determined and displayed as a time profile. Due to mathematical relationships, it is ultimately not crucial for the invention which of the variables—position, velocity, or acceleration—is measured. For example, angular position and angular acceleration are related to the angular velocity via time-based integration or differentiation.Instead of the angular velocity, the rotational movement can therefore also be represented by the angular position or angular acceleration, in particular their temporal progressions. It is preferred if a sensor signal from the sensor is fed to a signal processing unit, in particular before the disturbance torque is determined, in order to extract a component of the rotational movement caused by the disturbance torque, preferably wherein the signal processing unit comprises: bandpass filtering to suppress frequencies above and below a range of expected frequencies of the disturbance torque, and / or rectification and / or low-pass filtering. The signal processing can suppress signal components that cannot be assigned to the rotational movement due to the disturbance torque. In this context, "extracting" means that signal components are not suppressed by the signal processing unit, but are used for further processing.Since disturbance torques to be determined, in particular torsional moments of rolling vibrations, usually occur in certain frequency ranges, it is advantageous to filter out or suppress signal components of other frequencies outside this frequency range. Rolling vibrations, in particular torsional moments of the first eigenmode of a torsion of the wheelset shaft, typically occur in a frequency range between 60 and 150 Hz, in particular between 80 Hz and 140 Hz. For this reason, a bandpass filter, in particular digital, can be provided, which essentially suppresses frequencies above and below this frequency range. The range of the expected frequencies of the torsional moment of rolling vibrations is therefore preferably between 60 Hz and 150 Hz, in particular between 80 Hz and 140 Hz.By selecting a frequency range, disturbance torques can be determined even if the (natural) frequencies of the rolling vibrations change due to wear on the wheels of the wheelset. The first and most important eigenmode of torsion due to rolling vibration has (natural) frequencies between 60 Hz and 150 Hz, in particular between 80 Hz and 140 Hz, for typical wheelsets. Signal processing can also include rectification of the detected rotary movement and subsequent low-pass filtering to filter out unwanted frequencies. In this way, a positive value, in particular an amplitude, can be obtained from the temporal profile of the rotary movement, which represents the rotary movement. If the rotary movement is represented by an angular velocity, for example, the signal processing determines an angular velocity amplitude of the unwanted movement, in particular a rolling vibration.The amplitude can be in the form of an envelope of the rotary motion. The cutoff frequency of the low-pass filter can be between 8 Hz and 20 Hz, preferably between 10 Hz and 15 Hz, for example 12 Hz. The value obtained after signal processing can be linked, in particular multiplied, with the conversion factor to obtain the disturbance torque. It is possible to first link the conversion factor to the signal and then feed the signal to the signal processing. However, it is preferred if the signal processing is performed before linking it to the conversion factor. The signal processing can, but does not have to, be performed in the specified order – first bandpass filtering, then rectification, and finally low-pass filtering.Since the signal processing filters can introduce unwanted signal attenuation, it can be advantageous to link the sensor signal, particularly after signal processing, with a scaling factor in order to essentially compensate for any attenuation of the signal processing. This avoids errors in determining the disturbance torque. The size of the scaling factor depends on the attenuation by the individual filters, i.e., the ratio of the signal magnitude at the input and output of a filter. However, it is also possible to scale the individual filters or signal processing elements (bandpass filtering, low-pass filtering and / or rectification) in such a way that no attenuation is introduced and therefore no separate scaling factor is required.In this case, the envelope of the angular velocity amplitude is already determined with sufficient accuracy by scaling the filters or signal processing elements in the passband of the filters. The scaling factor can be linked to the sensor signal, in particular by multiplication. If the signal processing filters are standardized and do not introduce any attenuation, the scaling factor can be omitted or the scaling factor can be 1. It is also possible for the scaling factor to be included in the conversion factor. In one example, the value of the scaling factor can be between 1 and 2. The sensor signal can be linked, in particular multiplied, with the conversion factor, in particular after signal processing, in order to obtain the disturbance torque, preferably an amplitude of the disturbance torque, in particular an amplitude of an envelope of the disturbance torque.If the amplitude of the disturbance torque acting on the wheelset axle changes, the rotational movement, in particular the angular velocity, and thus the sensor signal and also the disturbance torque determined using the method also change. This allows the current disturbance torque to be determined at any time. The conversion factor can be constant or variable over time. If bandpass filtering with an upper and lower cutoff frequency, rectification, and subsequent low-pass filtering are applied to the sensor signal, an envelope of the rotational movement, preferably an envelope of the angular velocity or another related variable, is recorded and processed as a consequence of the rolling vibration. Accordingly, in this case, an envelope of the disturbance torque is also obtained.If the rotational movement is recorded and processed as an angular velocity, the 22021 11 / 31 conversion factor for a generic wheelset can be between 25,000 Nm / (rad / s) and 30,000 Nm / (rad / s). The conversion factor can correspond to the torsional spring stiffness of the wheelset shaft or be derived therefrom if the disturbance torque, in particular a torsional moment, is determined based on a difference between the angular positions recorded by two sensors on the wheelset shaft. In one embodiment of the invention, the conversion factor can be determined using a mathematical model of the wheelset shaft, preferably a mathematical model of a wheelset comprising the wheelset shaft, or can have been determined before carrying out the method. The conversion factor can be determined analytically or numerically using the model.Changes in the wheelset geometry or mass distribution, which can arise in particular from wheelset wear, can be taken into account in the mathematical model. For this purpose, parameters and variables can be adjusted in the mathematical model to take the changed geometry and mass distribution into account. The adjustment of the parameters and variables can be carried out by estimation based on the kilometers driven by the wheelset or after measuring the wheelset. The conversion factor can be determined before application of the method and / or during the method based on the mathematical model. In one embodiment, the conversion factor can be determined at time intervals based on the mathematical model. In the following, a conversion factor between a torsional moment of the wheelset shaft and an associated angular velocity amplitude of the wheelset shaft is determined.In an exemplary simplified mathematical model, a mechanical replacement system is used for the wheelset, in which a torsion spring with a torsional spring stiffness k is located in the center of the wheelset shaft or instead of the wheelset shaft. T is assumed (see also the figure description below). A typical torsional spring stiffness is 3.7*10 7 Nm / rad. The mass inertia of the wheelset is denoted by θ and can be, for example, 105 kg m 2 be assumed. From the 22021 12 / 31 torsional spring stiffness k T and the mass inertia θ of the wheelset, the first torsional natural frequency determine. The torsional natural frequency ^ ^ is essentially constant, provided that the mass inertia θ of the wheelset and the torsional spring stiffness k T does not change. The following equation can be used to describe the twisting under torsion: [ ^^^ ( ^ )φ ^( x, t )]^ = −^ ^ ( ^ ) = 0. (2) Here ^^ ^ ( ^ ) the torsional stiffness and ^ ^ (^) the distributed torsional moment. The distributed torsional moment is specified and set to zero in equation (2). The variable x denotes a position along the wheelset shaft, the variable t denotes time. The dashes ' denote the local derivative. Equation (2) describes the steady state under torsion. The twist can be separated using the separation approach to φ(x, t) = Φ(x) q(t) (3), where Φ(x) denotes the shape of the torsional mode from the simplified mechanical equivalent system (in particular the first eigenmode of torsion, see also figure description below) and ^(^) denotes a generalized coordinate. For ^(^), a harmonic oscillation ^ ( ^ ) = ^ sin (^ ^ ^) (4) with an amplitude A and the frequency can be assumed. For equation (3) it follows that φ ( x, t ) = Φ ( x ) ^ sin (^ ^ ^) (5) and from this for the angular velocity cos (^ ^ ^) (6) For the angular amplitude and the angular velocity amplitude at the point x=a we get φ ^ (a) = ^ Φ(a) and ^ ^ (^) = ^ Φ(a) ^ ^ . (7) 22021 13 / 31 The amplitude A of the generalized coordinate or the generalized coordinate ^(^) can be expressed as follows: and For the torsional moment M T applies ^ ^ ( ^, ^ ) = ^ ^ ^ ( ^ ) φ ^( x, t ) , (10) where ^ ^ (^) is the moment of inertia and ^ is the shear modulus, which depend on the material used and the geometry of the wheelset. Using equation (9), ^ ^ (^, ^) and thus for equation (10) The amplitude of the torsional moment is thus calculated as which results in the conversion factor U results. Φ ( a ) and Φ ^( x ) result from the solution of the differential equation (2) using boundary conditions. is given by equation (1). The angular velocity ^ ^ ( ^ )at point a can be detected by the at least one sensor. By solving the equations and inserting parameters, a conversion factor is obtained which can, for example, be between 25,000 Nm / (rad / s) and 30,000 Nm / (rad / s). The conversion factor U given in equation (14) represents a link between the angular velocity of the wheelset shaft and the disturbance torque. However, this is only one possible embodiment of the invention. Other conversion factors also exist, for example between the disturbance torque and an angular acceleration or between the disturbance torque and a difference between two 22021 14 / 31 angular positions of the wheelset shaft, each of which is detected by a sensor. Alternatively, the conversion factor can preferably have been determined before carrying out the method using a metrological determination method on the wheelset shaft, preferably on a wheelset comprising the wheelset shaft.For this purpose, one or more strain gauges can be arranged on the wheelset or on a similar wheelset and the rotational movement, in particular the angular position, angular velocity and / or angular acceleration, of the wheelset axle can be measured. Using the strain gauges, any disturbance torques that occur, in particular torsional moments, can be determined and compared to the measured rotational movement. The ratio represents the conversion factor. The strain gauge(s) are attached directly to the wheelset axle and preferably 50 mm to 150 mm from a wheel. For example, strain gauges can be arranged on the wheelset axle approximately 100 mm from the inside of a wheel of the wheelset. In the metrological determination method, the structure containing the wheelset axle is operated in an operating range in which the structure is prone to rolling vibrations.Such an operating range occurs, for example, when a high drive torque is applied to the wheelset axle and / or the rails are wet. If a rolling vibration occurs, the disturbance torque, in particular the torsional moment, can be determined with the aid of the strain gauge(s) and related to the detected rotational movement in order to determine the conversion factor. In one embodiment of the invention, the rotational movement is detected by at least two sensors on the wheelset axle, preferably with the two sensors being arranged at opposite end regions of the wheelset axle, in particular at opposite ends of the wheelset axle. The advantage here is that rolling vibrations can be clearly differentiated from other vibrations due to the associated torsional movement, since the two sensors experience opposite movements in the event of torsion.22021 15 / 31 This avoids errors in determining the disturbance torque. As already mentioned above, the described method already works with a single sensor because undesired movements, in particular rolling vibrations, usually occur in a specific frequency interval and can therefore be identified based on their frequency. In a preferred embodiment of the invention, the disturbance torque can be determined based on a difference between the rotational movements of the wheelset shaft detected by the respective sensors. For this purpose, for example, the difference between the angular positions detected by the sensors can be used. Alternatively, the difference between the angular velocities or angular accelerations can also be used. The difference between the angular positions or the other variables can be fed into a signal processing system, as described above.The conversion factor can be used to determine the disturbance torque, in particular the amplitude of the disturbance torque. If the difference in the angular positions is used to determine the disturbance torque, the conversion factor can correspond to or be derived from the torsional spring stiffness of the wheelset axle. Over time, the wheels of a wheelset wear out, which changes the weight distribution and geometry of the wheelset. As a result, the frequencies and amplitudes of the rolling vibrations or torsional moments can also change. To avoid errors in determining the disturbance torques, it is therefore advantageous to adapt the conversion factor to a changing wheel diameter of a wheel arranged on the wheelset axle. The change in the conversion factor can be made, in particular, using a mathematical model (see above) or based on tests on the wheelset or a similar wheelset.The conversion factor can be adjusted, for example, depending on the kilometers traveled by the wheelset and / or the duration of use. Alternatively, the wheel diameter can be measured at intervals, and the conversion factor can be adjusted based on these measurements. 22021 16 / 31 The described method for determining a disturbance torque acting on a wheelset axle of a rail vehicle can also be used in a method for controlling and / or regulating a rail vehicle according to claim 10. Such a method for controlling and / or regulating can comprise the following steps: determining a disturbance torque according to the method described above for determining a disturbance torque; and changing a setpoint specification of a traction, in particular reducing the acceleration, if the disturbance torque exceeds a disturbance torque threshold.Reducing the acceleration means that the magnitude of the acceleration is reduced. Therefore, if the acceleration assumes a negative value (braking, i.e. reducing the speed), reducing the acceleration in this context means that the braking is less severe. Rolling vibrations often occur during acceleration (increasing or reducing the speed). For this reason, rolling vibrations can be suppressed by reducing the acceleration of the rail vehicle. The disturbance torque threshold above which the traction setpoint is changed is preferably between 5 kNm and 10 kNm. In a particularly preferred embodiment, the change in the setpoint depends on the detected disturbance torque. The higher the disturbance torque, the more the acceleration can be reduced, for example.For example, a linear relationship may exist between the disturbance torque and the reduction in acceleration. The above-described object is also achieved by a system for determining a disturbance torque acting on a wheelset axle of a rail vehicle, in particular a torsional moment of a rolling vibration, according to claim 11. Such a system comprises: 22021 17 / 31 at least one, preferably at least two, sensor(s) for detecting a rotational movement of a wheelset axle, in particular an angular velocity; and a processing unit connected to the at least one sensor, wherein the processing unit is configured to determine the disturbance torque, in particular an amplitude of the disturbance torque, from the rotational movement using a conversion factor.The system is accordingly configured to carry out the above-described method for determining a disturbance torque acting on a wheelset axle of a rail vehicle. The advantages and features described in connection with the method for determining a disturbance torque acting on a wheelset axle of a rail vehicle can therefore be transferred to the system. The processing unit can be formed, for example, by a microprocessor or part of a computer. The processing unit can be connected to the at least one sensor by means of a cable or wirelessly. The processing unit is preferably arranged on or in the rail vehicle. However, it is also conceivable for the processing unit to be integrated into a remote server. The system for determining a disturbance torque acting on a wheelset axle of a rail vehicle can be used in a rail vehicle according to claim 12.The rail vehicle has at least one wheelset having a wheelset axle. The sensor or a part of the sensor is preferably arranged on the wheelset axle. It is advantageous if the at least one sensor is arranged at a distance from a vibration node of a first eigenmode of a torsion of the wheelset axle, which occurs in particular during a rolling vibration, as viewed in a longitudinal direction of the wheelset axle. If the wheelset or wheelset axle is constructed symmetrically, the vibration node of the first eigenmode of the torsion of the wheelset axle is located substantially in the geometric wheelset axle center. It is therefore preferred if the 22021 18 / 31 at least one sensor is spaced from a geometric wheelset axle center. If the wheelset axle or wheelset is not constructed symmetrically, the vibration node is not located in the geometric wheelset axle center, but offset from it.Since rotational movement cannot be detected at the vibration node, it is advantageous not to arrange the at least one sensor at the vibration node. It is preferred if the at least one sensor is arranged at an outer end region of the wheelset shaft, preferably at one end of the wheelset shaft. If two sensors are used, which is advantageous with regard to the clear identification of torsional moments, it is advantageous if they are arranged at opposite end regions of the wheelset shaft, in particular opposite ends of the wheelset shaft. In one embodiment of the invention, it is provided that the at least one sensor has a stationary sensor head and a rotor that is rotatable relative to the sensor head and is preferably magnetized and coded, and the rotational movement of the wheelset shaft can be detected via the rotation of the rotor. The rotor is arranged directly on the wheelset shaft or on an element that is connected to the wheelset shaft in a rotationally fixed manner.As a result, the rotor follows the rotational movement of the wheelset shaft. The coding of the rotor allows the angular position or the change in the angular position of the wheelset shaft to be recorded. The angular velocity can be determined from the angular position by time derivative. The angular velocity can be determined directly from the change in angular position. The sensor head is stationary relative to the wheelset shaft. Brief description of the drawings The invention is described in more detail below with reference to figures, to which it is not intended to be limited. They show: Fig. 1 a simplified representation of a wheelset with two sensors; Fig. 2 a mechanical equivalent circuit diagram of a wheelset; Fig. 3A signal processing; Fig. 3B signal processing; 22021 19 / 31 Fig. 4A-C time diagrams of an angular velocity, an amplitude and a torque; Fig. 5 a simplified representation of a rail vehicle in a side view; Fig.6 is a flow diagram; Fig. 7A is a diagram of a torsion in which the angle of twist is visible as a function of the position along a wheelset shaft; and Fig. 7B is a diagram of a torsion in which the torsional moment of a torsion is visible as a function of the position along a wheelset shaft. Description of the embodiments Fig. 1 shows a simplified representation of a wheelset 1 of a rail vehicle 27 (see Fig. 5) in a front view. The wheelset 1 has a wheelset shaft 2 and two wheels 3a, 3b connected to the wheelset shaft 2. The wheels 3a, 3b have a wheel diameter Da, Db. The distance between the wheels 3a, 3b is adapted to the distance between the rails of a track 28 (see Fig. 5). The wheels 3a, 3b are arranged on the wheelset shaft 2 in a rotationally fixed manner.The wheelset shaft 2 passes through a through opening of each of the two wheels 3a, 3b, so that opposite end regions 4a, 4b of the wheelset shaft 2 each protrude outwards from a geometric center 8 of the wheelset shaft 2, as seen from the wheels 3a, 3b. In the illustration shown, a sensor 5a, 5b is provided at each of the end regions 4a, 4b of the wheelset shaft 2 for detecting a rotational movement 6a, 6b of the wheelset shaft 2. Due to the arrangement of the sensors 5a, 5b at the end regions 4a, 4b of the wheelset shaft 2, the sensors 5a, 5b are spaced from the geometric center 8 of the wheelset shaft 2, as seen in a longitudinal direction 7 of the wheelset shaft 2, and thus also from a center of gravity 9 of the wheelset shaft 2, which in the example shown coincides with the geometric center 8. The sensors 5a, 5b could also be arranged between the wheels 3a, 3b.For the method according to the invention, it is advantageous for detecting rotational movements 6a, 6b if the sensors 5a, 5b are arranged as far as possible from possible vibration nodes 52 of a torsion 14, in particular from the vibration node of the first eigenmode of the torsion 14 (see Fig. 7A). In the case of a symmetrically constructed wheelset 1, the vibration node 52 of the first eigenmode of the torsion 14 coincides with the geometric center 8 of the wheelset shaft 2, which is why an arrangement of the sensors 5a, 5b at the end regions 4a, 4b is advantageous. The sensors 5a, 5b are designed similarly in the illustration shown and each comprise a sensor head 10a, 10b and a rotor 11a, 11b that is rotatable relative to the sensor head 10a, 10b and has a preferably magnetized coding. However, other coding types, such as coding using optical patterns, are also applicable.The rotor 11a, 11b can, for example, be in the form of a ring attached to the wheelset shaft 2. The sensor head 10a, 10b can be attached to a frame or chassis of the rail vehicle 27. The rotational movement 6a, 6b of the wheelset shaft 2 is detected via the rotation of the rotor 11a, 11b and detection of the coding by the sensor head 10a, 10b and transmitted wired or wirelessly to a processing unit 12. In a preferred embodiment, the processing unit 12 is arranged in or on the rail vehicle 27. The rotational movement 6a, 6b can, for example, be detected in the form of an angular velocity ω_a, ω_b of the wheelset shaft 2 and transmitted to the processing unit 12 as a sensor signal 50. A sensor 5a, 5b detects the rotational movement 6a, 6b at that longitudinal position of the wheelset shaft 2, viewed in the longitudinal direction 7, at which it is arranged.It is also possible to record the rotational movement 6a, 6b, for example, as an angular position φ_a, φ_b or as angular acceleration and transmit it to the processing unit 12. The angular velocity ω_a, ω_b can be determined from these variables. During operation of rail vehicles 27, disturbance torques M can occur on a wheelset 1, particularly between the wheels 3a, 3b. Stör_a , M Stör_b occur, which cause undesired rotational movements 6a, 6b and can restrict the operation of the rail vehicle 27 or even lead to damage and wear. An example of such undesired rotational movements 6a, 6b are rolling vibrations 13, which usually occur when a rail vehicle 27 starts or brakes and lead to torsions 14, ie, distortions, of the wheelset shaft 2. The disturbance torque M Stör_a , M Stör_b can also be used as torsional moment M in the case of rolling vibrations 13 Tors_a , M Tors_bA torsion 14 of a wheelset shaft 2 is also illustrated in Fig. 7A and Fig. 7B. The rolling vibration 13 is shown in more detail in Fig. 2. Fig. 2 shows a simplified mechanical equivalent circuit diagram of a wheelset 1 with a torsion spring 15 as wheelset shaft 2 and two rigid bodies 16a, 16b as wheels 3a, 3b, which are connected to one another via the torsion spring 15. The rolling vibration 13 is illustrated by a torsion 14 of the torsion spring 15, which leads to the rigid bodies 16a, 16b or the wheels 3a, 3b and the end regions 4a, 4b of the wheelset shaft 2 being twisted in opposite directions to one another. The torsion 14 can be superimposed on a (desired) torsion-free forward or reverse rotation 17 of the wheelset shaft 2 for moving the rail vehicle 27. The torsion 14 is determined by the disturbance torques M Stör_a , M Stör_b or M Tors_a , M Tors_bbetween the wheels 3a, 3b. The rotational movement 6a, 6b of the wheelset shaft 2 can be detected at the end regions 4a, 4b, even if the end regions 4a, 4b themselves are essentially free of disturbing torques M Stör_a , M Stör_b The disturbance torque M Stör_a is detected by the sensor 5a via the rotational movement 6a and the disturbance torque M Stör_b determined by the sensor 5b via the rotational movement 6b. The disturbance torques M Stör_a , M Stör_b are essentially the same size, especially in the first eigenmode of a torsion 14, since the torsional moment of a wheelset shaft 2 is essentially constant along the wheelset shaft 2 (see Fig.7B). Since the magnitude of the disturbance torques M Stör_a , M Stör_b or M Tors_a , M Tors_bat least for the first eigenmode is essentially the same and this is preferably determined using the method according to the invention, it is also possible to determine the disturbance torque acting on the wheelset shaft 2 using a single sensor 5a, 5b. If the disturbance torque M Stör_a known, can also be used on M Stör_b For this reason, to determine a disturbance torque M Stör_a , M Stör_band thus only a single sensor 5a, 5b is required for the invention. A second sensor 5a, 5b is not needed. However, the use of a second sensor 5a, 5b at the other end region 4a, 4b of the wheelset shaft 2, as shown in Fig. 1, is preferred in order to be able to confirm whether it is actually a torsion 14, so that incorrect determinations can be avoided. A torsion 14 is present when the sensors 5a, 5b detect different, in particular opposing, rotational movements 6a, 6b of the wheelset shaft 2. Since the torsion 14 has the greatest amplitude effect at the end regions 4a, 4b of the wheelset shaft 2, sensors 5a, 5b are preferably arranged at the end regions 4a, 4b of the wheelset shaft. The disturbance torques M occurring during rolling vibrations 13 Stör_a , M Stör_bcan be very high and, if no countermeasures are taken, lead to heavy loading of the wheelset 1 and increased wear. It is known from the prior art to detect the occurrence of rolling vibrations 13 and to implement countermeasures, however, independent of the intensity of the rolling vibrations 13, which is not determined in the prior art. Thus, the countermeasures cannot be specifically adapted to the rolling vibrations 13 in the prior art. If a disturbance torque M Stör_a , M Stör_b on a wheelset 1 is very large, it may be necessary to take further or targeted countermeasures immediately to avoid damage to the rail vehicle 27. If a disturbance torque M Stör_a , M Stör_bHowever, if the torque is very small, no countermeasures or only mild countermeasures may be required, which do not or only slightly restrict the operation of the rail vehicle 27. In order to be able to take targeted countermeasures when undesired movements occur, the invention provides for detecting the rotational movement 6a, 6b of the wheelset shaft 2 by at least one sensor 5a, 5b and measuring the disturbance torque M Stör_a , M Stör_b , preferably an amplitude A_a, A_b of the disturbance torque M Stör_a , M Stör_b , from the rotational movement 6a, 6b using a conversion factor U. The conversion factor U links the rotational movement 6a, 6b, in particular an angular velocity or a related quantity, 23 / 31 with the disturbance torque M Stör_a , M Stör_bThis is illustrated in Fig. 3A using the example of a preferred embodiment of the invention. Fig. 3A shows the determination of the amplitude A_a of an occurring disturbance torque M Stör_a , whereby the rotational movement 6a is detected by the sensor 5a. In the same way, the amplitude A_b of the disturbance torque M Stör_b In the case of a rolling vibration 13, the recorded rotational movements 6a, 6b would lead to the same results if the torsional moment M Tors_a , M Tors_b the first eigenform of a torsion 14, since the torsional moment M Tors_a , M Tors_b along the wheelset shaft 2 is essentially constant during the first eigenform of the torsion 14. A second sensor 5a, 5b is not required for the invention, as mentioned, but is preferred in order to detect incorrect determinations, e.g., when no torsion 14 is present at all. The amplitude A_a of the disturbance torque M Stör_acan be determined on the basis of the rotational movement 6a after signal processing 18. The method is preferably carried out by the processing unit 12, in which the individual steps of the signal processing 18 can be implemented. The rotational movement 6a detected by the sensor 5a, preferably a measured angular velocity ω_a of the wheelset shaft 2, is contained in a sensor signal 50 and, in a preferred embodiment of the invention, is first band-pass filtered in a block 19. The band-pass filter in block 19 preferably suppresses frequencies below 60 Hz and above 150 Hz. Rolling vibrations 13 typically have mainly frequencies that lie within the frequency band between 60 Hz and 150 Hz. The sensor signal 50 is then rectified in block 20 and low-pass filtered in block 21. The cutoff frequency of the low-pass filter in block 21 is preferably between 8 Hz and 20 Hz. The sensor signal 50 orThe angular velocity ω_a is then multiplied by a scaling factor S (block 22) to substantially compensate for any attenuation of the signal processing 18. If the processing in blocks 19, 20, and 21 is scaled, a scaling factor S is not necessary, or S = 1. The signal is then multiplied by a conversion factor U (block 23) to obtain an amplitude A_a of 22021 24 / 31 of the disturbance torque M. Stör_aThe conversion factor U can be between 25,000 Nm / (rad / s) and 30,000 Nm / (rad / s) for an exemplary gear set 1. It is preferred if the processing of the signal 50 is carried out in the specified order. However, it is also possible, for example, to first link the signal 50 with the conversion factor U and then to carry out bandpass filtering, rectification, and lowpass filtering. With the help of the second sensor 5b, it can be checked whether torsion 14 is actually present by determining whether opposing rotational movements 6a, 6b are present. In an embodiment of the invention in which two sensors 5a, 5b are used as shown in Fig. 1, the disturbance torque M Stör_a , M Stör_b based on the difference between the rotational movements 6a, 6b detected by the sensors 5a, 5b. For example, the disturbance torque M Stör_a , M Stör_b, which, as mentioned, is essentially constant along the wheelset shaft 2 during the first eigenform of the torsion 14, can be determined on the basis of the difference between the angular positions φ_a, φ_b detected by the sensors 5a, 5b and the conversion factor U. The conversion factor U can, in the case of determining the disturbance torque M Stör_a , M Stör_b based on the difference in the angular positions of the torsional spring stiffness of the wheelset shaft 2 or derived from it, ie determined. In order to determine the amplitude of the disturbance torque M Stör_a , M Stör_b To obtain the desired torque, the difference in the rotational movement 6a, 6b, in particular the angular positions φ_a, φ_b, can be fed to the signal processing 18 according to Fig. 3A, as illustrated in Fig. 3B. The explanations for Fig. 3A are analogously transferable to Fig. 3B. Figs. 4A-C show time diagrams of the sensor signal 50 in determining the disturbance torque M Stör_a , M Stör_baccording to Fig. 3A. All three time diagrams Fig. 4A-C each show the same time segment of the original (see Fig. 4A) or partially processed (see Fig. 4B-C) signal 50. The time diagrams Fig. 4A-C are aligned such that identical points in time in the time diagrams Fig. 4A-C are arranged directly above one another. The abscissa of the time diagrams Fig. 4A-C represents the time t(s) in seconds. The ordinates 22021 25 / 31 of the time diagrams Fig. 4A and Fig. 4B represent an angular velocity in rad / s. The ordinate of the time diagram Fig. 4C represents a torque in kNm. In Fig. 4A, a time curve of the rotational movement 6a of the wheelset shaft 2 is shown as angular velocity ω_a in rad / s. It can be seen in Fig. 4A that the wheelset shaft 2 is initially moving at an angular velocity of approximately 7.5 rad / s. This represents a desired forward movement 17 of the wheelset shaft 2.After approximately 0.15 seconds, a rolling oscillation 13 is superimposed on the forward movement 17. Its amplitude continues to increase and is recognizable by a temporal oscillation of the angular velocity ω_a. The rolling oscillation 13 ends again after approximately 1.15 seconds. The rolling oscillation 13, or rather the disturbance torque M occurring in connection with the rolling oscillation 13, Stör_acan lead to increased wear or damage to the rail vehicle 27. Fig. 4B shows the sensor signal 50 after bandpass filtering (block 19), rectification (block 20), low-pass filtering (block 21), and multiplication by the unitless scaling factor S (block 22). Through these processing steps, the unit rad / s of the original signal is retained. In Fig. 4B, an amplitude curve 24 of the rolling vibration 13 can be seen, which can also be referred to as the envelope of the angular velocity ω_a. Fig. 4C shows the sensor signal 50 after combination with the conversion factor U, which has the unit Nm / (rad / s). After combination with the conversion factor U, the sensor signal 50 shows a time curve 25 (see the dashed line) of the amplitude A_a of the disturbance torque M Stör_a , which is also known as the envelope of the disturbance torque M Stör_aFor comparison, a measured torque curve 26 is also shown, which shows the disturbance torque M actually acting on the wheelset shaft 2 Stör_a and generates the rolling vibration 13. It can be seen that the envelope 25 of the disturbance torque M Stör_a essentially envelops the torque curve 26 and thus the amplitude A_a of the disturbance torque M Stör_a over time t. 22021 26 / 31 Fig.5 shows a rail vehicle 27 traveling along a track 28 and accelerating in the direction of travel 29. The rail vehicle 27 has a system 51 for determining a disturbance torque M acting on a wheelset axle 2 of a wheelset 1 Stör_a , M Stör_b , consisting of a sensor 5a and a processing unit 12. The processing unit 12 is connected to the sensor 5a. The processing unit 12 is configured to carry out the method according to the invention and to determine the disturbance torque M Stör_ato determine and output. As described above, M Stör_a also M Stör_b , when the torsional moment of the first eigenmode of torsion 14 is determined. If the disturbance torque M Stör_a a limit value M Grenz exceeds, a countermeasure can be taken to suppress the rolling vibration. For example, it can be provided to reduce the acceleration of a drive 30 of the rail vehicle 27. The system 51 can also have a second sensor 5b, with which it can be checked whether a torsion 14 actually exists and / or to determine the disturbance torque M Stör_a , M Stör_b based on the difference between the rotational movements 6a, 6b. Fig.6 shows a step-by-step process of a method for controlling and / or regulating a rail vehicle 27. In step 201, a disturbance torque M Stör_a , M Stör_b , preferably an amplitude A_a, A_b of the disturbance torque M Stör_a , M Stör_bSubsequently, in step 202, the disturbance torque M Stör_a , M Stör_b with a disturbance torque threshold M Grenz By evaluating the sensor signals 50 from two sensors 5a, 5b on the wheelset shaft 2 at opposite end regions 4a, 4b, it can be checked whether a torsion 14 is actually present in order to avoid incorrect countermeasures being taken. If the disturbance torque M Stör_a , M Stör_b greater than the disturbance torque threshold M Grenz , a countermeasure is taken in step 203. In particular, it can be provided that a setpoint specification of a traction is changed, in particular an acceleration of the rail vehicle 27 is reduced. The reduction in the acceleration can depend on the magnitude of the disturbance torque M Stör_a , M Stör_b The larger the 22021 27 / 31 disturbance torque M Stör_a , M Stör_b, the more the traction setpoint can be changed. Fig. 7A shows a standardized angle α of a torsion 14 according to the first eigenmode of a wheelset shaft 2 along the position x of the wheelset shaft 2, which can, for example, have a length of 218 cm. The wheelset 1 or the wheelset shaft 2, on the basis of which the curves of the angle α and the moment T (see Fig. 7B) were determined, is not symmetrical, which is why the vibration node 52 at α = 0 is not located in the geometric center 8 of the wheelset shaft 2 at x = 1. The flattened curve of the angle α in the range x = 1 is due to a gear (not shown) for driving the wheelset shaft 2. The angle α is a standardized angle, related to the maximum twist angle. Fig. 7B shows a standardized torsional moment T, related to a maximum value of the torsional moment M Tors_a , M Tors_b, along the position x of the wheelset shaft 2 according to Fig.7A. The torsional moment T shown corresponds to the torsional moment of the first eigenmode of the wheelset shaft 2. It can be seen that the torsional moment T is essentially constant along the entire wheelset shaft 2.

Claims

22021 28 / 31 Patent claims 1. Method for determining a disturbance torque (M Stör_a , M Stör_b ), in particular a torsional moment (M Tors_a , M Tors_b ) of a rolling vibration (13), comprising the following steps: detecting a rotational movement (6a, 6b) of the wheelset shaft (1) by at least one sensor (5a, 5b), preferably on the wheelset shaft (2); and determining the disturbance torque (M Stör_a , M Stör_b ), preferably an amplitude (A_a, A_b) of the disturbance torque (M Stör_a , M Stör_b), from the rotational movement (6a, 6b) using a conversion factor (U).

2. Method according to claim 1, characterized in that the rotational movement (6a, 6b) is represented by an angular position (φ_a, φ_b), an angular velocity (ω_a, ω_b), an angular acceleration of the wheelset shaft (2) or a related, preferably proportional, variable.

3. Method according to claim 1 or 2, characterized in that a sensor signal (50) of the sensor (5a, 5b), in particular before determining the disturbance torque (M Stör_a , M Stör_b ) is fed to a signal processing unit (18) in order to determine a disturbance torque (M Stör_a , M Stör_b ) caused portion of the rotational movement (6a, 6b), preferably wherein the signal processing (3) comprises: a bandpass filter (19) to extract frequencies above and below a range of expected frequencies of the disturbance torque (M Stör_a , M Stör_b), and / or rectification (20) and / or low-pass filtering (21).

4. The method according to claim 3, characterized in that the sensor signal (50), in particular after the signal processing (18), is linked to a scaling factor (S) in order to substantially compensate for any attenuation of the signal processing (18). 22021 29 / 31 5. Method according to claim 3 or 4, characterized in that the sensor signal (50) is linked, in particular multiplied, with the conversion factor (U), in particular after the signal processing (18), in order to determine the disturbance torque (M Stör_a , M Stör_b ), preferably an amplitude (A_a, A_b) of the disturbance torque (M Stör_a , M Stör_b ), in particular an amplitude (A_a, A_b) of an envelope of the disturbance torque (M Stör), to obtain.

6. Method according to one of claims 1 to 5, characterized in that the conversion factor (U) is determined using a mathematical model of the wheelset shaft (2), preferably a mathematical model of a wheelset (1) comprising the wheelset shaft (2), or was determined before carrying out the method.

7. Method according to one of claims 1 to 5, characterized in that the conversion factor (U) was preferably determined before carrying out the method using a metrological determination method on the wheelset shaft (2), preferably on a wheelset (1) comprising the wheelset shaft (2). 8.Method according to one of claims 1 to 7, characterized in that the rotational movement (6a, 6b) is detected by at least two sensors (5a, 5b) on the wheelset shaft (2), preferably wherein the two sensors (5a, 5b) are arranged at opposite end regions (4a, 4b) of the wheelset shaft (2), in particular at opposite ends of the wheelset shaft (2).

9. Method according to claims 1 to 8, characterized in that the conversion factor (U) is adapted to a changing wheel diameter (D_a, D_b) of a wheel (9) arranged on the wheelset shaft (1).

10. Method for controlling and / or regulating a rail vehicle (27) with the following steps: determining a disturbance torque (A_a, A_b) according to the method according to one of claims 1 to 9; and. 22021 30 / 31 Changing a traction setpoint, in particular reducing acceleration, if the disturbance torque (M Stör_a , M Stör_b ) a disturbance torque threshold (M Grenz) exceeds.

11. System (51) for determining a disturbance torque (M Stör_a , M Stör_b ), in particular a torsional moment (M Tors_a , M Tors_b ) of a rolling vibration (13), comprising: at least one, preferably at least two, sensors (5a, 5b) for detecting a rotational movement (6a, 6b) of a wheelset shaft (2), preferably an angular velocity (ω_a, ω_b); and a processing unit (12) connected to the at least one sensor (5a, 5b), wherein the processing unit (12) is configured to determine the disturbance torque (M Stör_a , M Stör_b ), in particular an amplitude (A_a, A_b) of the disturbance torque (M Stör_a , M Stör_b), from the rotational movement (6a, 6b) using a conversion factor (U).

12. Rail vehicle (27) with at least one wheelset (1) having a wheelset shaft (2), characterized in that the rail vehicle (27) has a system (51) for determining a disturbance torque (M Stör_a , M Stör_b) according to claim 11, wherein the sensor (5a, 5b) is preferably arranged on the wheelset shaft (2).

13. Rail vehicle (27) according to claim 12, characterized in that the at least one sensor (5a, 5b), viewed in a longitudinal direction of the wheelset shaft (2), is arranged at a distance from a vibration node (52) of a first eigenmode of a torsion (14) of the wheelset shaft (2), which occurs in particular during a rolling vibration (13).

14. Rail vehicle (27) according to one of claims 12 to 13, characterized in that the at least one sensor (5a, 5b) is arranged on an outer end region (4a, 4b) of the wheelset shaft (2), preferably on one end of the wheelset shaft (2). 22021 31 / 31 15. Rail vehicle (27) according to one of claims 12 to 14, characterized in that the at least one sensor (5a, 5b) has a fixed sensor head (10, 10b) and a rotor (11a, 11b) which is rotatable relative to the sensor head (10a, 10b) and is preferably magnetized and coded, and the rotational movement (6a, 6b) of the wheelset shaft (2) can be detected via the rotation of the rotor (11a, 11b).

Images