Method for recording and consideration of crosswind loads in a traveling rail vehicle and its correspondingly designed end car The invention relates to a method for recording and consideration of crosswind loads on a traveling rail vehicle, in particular on a vehicle such as this which is traveling at a comparatively high speed of, for example, 200 to 400 km/h. The invention also relates to an end car of a rail vehicle, which is designed to carry out these two methods.
Particularly when trains are traveling at the high speeds that have been mentioned, any crosswind that occurs represents a risk of derailing, particularly when a strong crosswind, for example at more than 20 m/s, coincides with poor track conditions (for example a bend geometric position errors) . The risk of derailing must obviously be minimized. DB AG [German Railways] have issued a new guideline (Ril 401) relating to this with the aim of reducing the potential risk resulting from crosswinds acting on high-speed trains. This guideline specifies that every vehicle must have a wheel contact force of at least 10% of its stationary contact force at all times and on every wheel. An associated specialist article entitled "Seitenwindgefahr fur schnelle Reisezuge?" [Do crosswinds present a danger to high-speed trains) has appeared on page 24 of EI-Eisenbahningenieur (53) 10/2002.
As a precaution against the risk of derailing caused by crosswind, it is also possible to influence the configuration of the track route, for example by installing wind protection walls or wind protection fences. With regard to the vehicle, the contact force can be increased by aerodynamic shaping and ballasting, particularly in the case of the end car, which is generally most severely affected and heads the train. The dynamic parameters relating to the chassis, such as the masses, stiffnesses, dampers and their geometric arrangement, also in general influence the crosswind sensitivity of the train or rail vehicle. In addition to the measures on the track and the rail vehicle, the problem of safety in the event of extremely strong crosswind conditions is coped with by the operational measure of reducing the speed of travel. In strong wind situations such as these, a reduced maximum speed is stipulated, depending on a wind characteristic curve (WKK) of the rail vehicle. This is dependent on suitable wind measurement capabilities and warning capabilities with adequate positional resolution, and on the manual actions resulting from this by a traffic controller.
Against this background, the invention is based on the object of specifying a method which allows increased confidence that rail vehicles will not be derailed when traveling in the presence of a crosswind.
This object is achieved by a method for recording crosswind loads on a traveling rail vehicle, having the following steps:
a) recording of aerodynamic measurement data (for example pressures) on at least one first side surface section of the rail vehicle, b) recording of the speed of the rail vehicle, c) access to a reference table which contains relationships between aerodynamic measurement data, which can be detected in step a), of the traveling rail vehicle and of the associated incidence direction of the traveling rail vehicle, d) calculation of the magnitude and direction of the prevailing crosswind on the basis of the measurement data from step a), the vehicle speed from step b), and the reference table which is accessed in step c), e) recording of the track line section within which the measurement from step a) is carried out, and f) storage of the crosswind data calculated in step d), associated with the track line section recorded in step e), as position coordinates.
This method makes it possible to make statements about current crosswind conditions for that section of the track line on which the measurements of crosswind data are being carried out on the traveling rail vehicle, and to make predictions about crosswind conditions on the track line sections which will be traveled on next. Overall, the various method steps make it possible to obtain values for the respective current crosswind and, to store this in conjunction with position information, and preferably time information as well (date and time), and to initiate speed reductions if there is a predicted crosswind risk. In one particularly simple case, this method is carried out, for example, only at various points on the track section for which it has been known in advance that increased crosswind loads can be expected. This method may, of course, be carried out repeatedly when traveling over that track section repeatedly, to be precise in this case for the same track line sections for which crosswind data has already previously been determined. For example, this makes it possible to carry out a reliable statistical analysis of crosswind measured values over a large number of journeys on that track section.
It is, of course, advantageous for additional measurement data for at least one second side surface section of the rail vehicle, which is essentially opposite the first side surface section, to be recorded in step a).
It is, of course, likewise advantageous if, in step a), additional aerodynamic measurement data is recorded on a second side surface section which is essentially opposite and at a measurement point, which is located essentially on the vehicle longitudinal center line, of a rail vehicle head. If, for example, aerodynamic sensors are provided to carry out the method on each side and in the center of a rail vehicle in particular a head section of its end car, measured values can be recorded by all the sensors in order to obtain statements about crosswind loads.
In the situation in which information is already available about the value from which a potential hazard from crosswind loads exists (for example in the form of the wind characteristic curve of a rail vehicle), the crosswind pressure calculated in step d) can be stored in step f) only if a predetermined threshold value is exceeded, beyond which there is a risk to a rail vehicle in order to restrict the amount of data.
Steps a) to f) of the method can be carried out repeatedly in order to obtain a crosswind profile for a specific track section during a journey on that track section. A
correspondingly fine crosswind profile which is representative of crosswind loads on the corresponding track section is obtained with appropriate position resolution for carrying out the method.
The object mentioned above is also achieved by a method for consideration of crosswind conditions for a traveling rail vehicle, having the following steps:
A) a crosswind profile is obtained for a specific track section during a journey on that track section, B) the crosswind conditions are predicted for a track section lying ahead on the basis of the crosswind profile obtained in step A).
This method can be carried out in particular by using the method as described above for recording crosswind loads, and its embodiments, in which a section-dependent crosswind profile is obtained. The following steps, in particular, are suitable for prediction of the crosswind conditions based on step B):
g) the crosswind conditions are predicted on a track section lying immediately in front of the rail vehicle, h) the maximum permissible speed of travel relating to the crosswind conditions on the track section lying immediately in front of the rail vehicle is calculated by accessing a look-up table which contains data specific for that range of vehicles, i) the maximum permissible speed of travel relating to the predicted crosswind conditions is passed on to the person, people or technical devices driving the train, for example the train control system.
The prediction, carried out in step g), of the crosswind conditions for a track section lying ahead can be created directly on the basis of the current status of a recorded crosswind profile for the track section being traveled on.
Previous crosswind profiles recorded for the same track section and for the track section lying ahead may, of course, be included in the prediction in step g).
In order to improve the prediction result for step g), measurement results from fixed-position wind measurement devices in the vicinity of the track section may also be included in the prediction. In general, it is advantageous to evaluate any information from the crosswind profile which has currently been measured or else previous crosswind profiles relating to crosswind loads along the track section, for prediction purposes.
The prediction of the crosswind conditions in step g) can be produced using a computer correlation method, which makes use of the correlation between the current measurement data and measurement data recorded in the past for the section being traveled on, in order to make a prediction of the wind conditions of the section lying immediately in front of the traveling rail vehicle, by means of the associated measurement data from the past.
The data required for the crosswind prediction in step g) may be gathered and stored in the train more centrally. For central gathering of the data required for step g), it is advantageous for this data to be signaled to a stationary central computer which, for example, may be associated with the section control center, where general information relating to crosswind conditions on track sections can be gathered, and if appropriate cross-related. Access to the data in the stationary central computer then allows the prediction result in step g) to be improved further.
In step h) the maximum permissible speed is determined from the crosswind prediction created in step g) by means of a look-up table from predicted crosswind conditions which, for example, are described by the crosswind speed. This relationship between the crosswind conditions and the maximum permissible speed of travel in that crosswind is specific to one range of vehicles.
In step i), the maximum permissible speed determined in step h) is fed to the locomotive or train engineer himself or to the relevant personnel in the section control center, or to a technical device for train control. Appropriate operating instructions and procedures implemented in a technical device control actions and control signals derived therefrom.
It is likewise regarded as advantageous if, in step g), the prediction takes account of wind measurement data determined by means of at least one further rail vehicle which is traveling in particular in front on the same section in the same direction, or on the same section in the opposite direction. In this case, it is possible to obtain measurement data relating to the crosswind for the track section lying immediately in front, essentially in real time. This results in a particularly reliable prediction for the crosswind conditions which the rail vehicle will experience in the near future.
In addition to the currently obtained crosswind profile or else previously determined crosswind profiles for the relevant range of rail vehicles and a specific track section, further functions can be taken into account in step g) . These are preferably chosen from the group which comprises a plausibility check between the data of the two rail vehicles, data redundancy and a check of additional wind data from predetermined points on the track section. These functions are in some cases restricted to the embodiment of the invention in which measurement data is currently gathered from a further rail vehicle.
Steps g) to i) or parts of them or the further functions can be implemented in a stationary central computer which has communication links to the rail vehicles. However, it is likewise possible for the functions to be implemented directly on one of the rail vehicles involved, in which case all that is required is a direct communication link between the rail vehicles.
For the purposes of further development of the method, the next step after creation of the prediction according to step B) is, in a step C), to implement the result of step B) with regard to the prediction of the crosswind conditions in an action on a speed control system for the rail vehicle. This simply means that an action can be applied to the train control system if the predicted crosswind conditions require this. In this case, the action on the train control system may be manual, for example with a prediction result being visualized to an operator who then carries out the action on the train control system. However, it is likewise possible for the prediction result to be converted to a suitable control signal, which can then be automatically entered in the train control system.
The object mentioned above is likewise achieved by an end car of a rail vehicle having a detection device for crosswind measurement data on at least one first side surface section of the end car, a recording device for the speed of the rail vehicle, and a measurement data recording and processing device for accessing a reference table which contains relationships between recordable crosswind measurement data and the associated crosswind, and for calculation of the magnitude and direction of the crosswind on the surface section on the basis of the crosswind measurement data, the speed of the rail vehicle and the reference table.
Further developments of this end car can be found in dependent patent claims 20 to 26 and relate primarily to technical equipment elements such as aerodynamic sensors which allow the method steps, as explained above, to be carried out.
Exemplary embodiments of the invention will be explained in more detail in the following text with reference to the drawing, in which:
Figure 1 shows a block diagram illustration of a system for consideration of crosswind loads for controlling a rail vehicle, Figure 2 shows a block diagram illustration of a system for consideration of crosswind loads for a rail vehicle in a second embodiment, in which crosswind measurement data is received from a further rail vehicle, and Figure 3 shows a block diagram illustration of a system for consideration of crosswind loads on a rail vehicle according to a third embodiment, in which access is made to data from a stationary central computer in a section control center.
The block diagram illustration in Figure 1 of a system for consideration of crosswind loads on a rail vehicle shows a number of measured-value transmitters on the left-hand side, specifically three aerodynamic pressure sensors DS1, DS2, DS3, a recording device GE for the speed of the rail vehicle and a distance sensor WA which records the track line section, for example in the form of kilometers traveled. The aerodynamic sensors DS1, DS2, DS3 produce data whose values are passed together with the values from the recording device GE and the distance sensor WA to a measurement data recording and processing device MEV. The aerodynamic pressure sensors DS1, DS2, DS3 are advantageously fitted in the head area of an end car or of a rail vehicle, to be precise DS1 and DS2 on its opposite sides and DS3 at the front in the vicinity of the ram-air point of the incident flow on the end car or rail vehicle. The measurement data recording and processing device MEV calculates the prevailing crosswind and in particular the prevailing crosswind speed from the measurement data from the recording device GE for the speed of the rail vehicle, from the measured values from the pressure sensors DS1, DS2, DS3, and for this purpose accesses a reference table in which the measured values of the pressure sensors DS1, DS2, DS3 are associated with the incident flow angle. A reference table such as this can be set up, for example, in advance in the course of computer simulation calculations, trials in a wind tunnel or while traveling. The reference table may also be in the form of a multidimensional field of characteristics.
An entry is made in a memory SP, in which crosswind data is gathered continuously and associated with kilometers traveled as position coordinates, on the basis of the determined crosswind data and an associated value for the number of kilometers traveled and an associated date stamp, with the aid of the measurement data recording and processing device MEV. In this way, the arrangement illustrated in Figure 1 "learns" the crosswind conditions when traveling over a predetermined track section.
A prediction device PE for prediction of the crosswind conditions for a track section lying just in front and, for example, covering a number of kilometers accesses the data in the memory SP and analyzes it. By way of example, a prediction can be obtained by correlation between the crosswind data from the kilometer section most recently traveled over with older crosswind data for the same line section for the nearest kilometer in front. Not only the currently obtained crosswind measurement data but also crosswind profiles obtained earlier for the same track section can be used in the memory SP for this purpose. The crosswind profiles obtained earlier can in fact be analyzed in advance of sections where there is a risk of strong crosswind on the track section, or with regard to other aspects, so that the results of analyses such as these can be taken into account by the prediction device PE.
An output signal from the prediction device PE then indicates crosswind loads to be expected for an approaching track line section and is passed to a speed control system GS for the rail vehicle. This speed control system GS can easily output warning signals if there is an expected risk of significant crosswind pressure loads, or else can itself act automatically on the speed control system for the rail vehicle. An automatic action such as this may comprise automatic restriction to the maximum speed of the rail vehicle. The speed control system GS may be located in the section control center or may possibly influence the maximum speed of the corresponding rail vehicle via a communication link.
The embodiment of an arrangement for consideration of crosswind loads on a traveling rail vehicle as shown in Figure 2 differs in one aspect from that which has been explained with reference to Figure 1. The prediction device PE is connected to a data transmission receiver DTE. The rail vehicle under consideration here receives data via this data transmission receiver DTE from a further rail vehicle which is located on the same track section in front of the rail vehicle under consideration here and is moving in the same or the opposite direction. This further rail vehicle is equipped with similar measurement data transmitters to those mentioned above, and likewise with a measurement data recording and processing device MEV. Currently determined data packets comprising crosswind data, details of kilometers traveled and time stamps which originate from the further rail vehicle are passed from the data transmission receiver DTE to the prediction device PE, which includes this measurement data in the prediction which is intended to be used for the next kilometer section for the rail vehicle. The rail vehicle itself may be equipped connected to a data transmission transmitter DTS, as is illustrated in Figure 2, so that the rail vehicle under consideration here can also act as a further rail vehicle transmitting measurement data. The data can be transmitted between the rail vehicles using existing communication media.
The arrangement shown in Figure 3 has the special feature over the arrangement shown in Figure 1 that data communication takes place with a stationary central computer ZR for a line section control center. An existing and secure communication medium is typically chosen once again, in order to allow data communication between the rail vehicle on the one hand and the stationary central computer ZR on the other hand, although the associated transmitters/receivers are not shown in the illustration in Figure 3. The train-based measurement data recording and processing device MEV transmits its data packets comprising crosswind data, details of kilometers traveled and time stamps to the stationary central computer ZR, so that crosswind profiles for the track section being traveled on are obtained at this point. Analysis for sections which are at risk of strong crosswinds or the like is likewise carried out at the stationary central computer ZR. Analysis results are transmitted from the stationary central computer ZR to the prediction device BE. Furthermore, the stationary central computer ZR has supplementary information, for example additional wind data from selected, representative or exposed points on the track section or information from one or more qualified meteorological services. If the embodiment as sown in Figure 3 is combined with that shown in Figure 2, that is to say further crosswind measurement data is provided by a further rail vehicle, a plausibility check or a redundancy check, for example, can also be carried out at the stationary central computer ZR. This allows investigation of whether the magnitude and direction of the crosswind data originating from the two rail vehicles involved match one another.
The major advantages which can be achieved by the invention are summarized briefly in the following text:
The rail vehicle can still be operated reliably when a strong crosswind occurs. In this case, any reduction in speed required for safety is in principle minimized, that is to say the maximum speed is reduced only in the event of predicted dangerous crosswinds. This may be done completely independently of a meteorological service by signaled manual actions or preferably automatically by the train control system. One consequence which is beneficial to the operator and specifically for the passengers is better punctuality of the rail vehicle. In addition, it is advantageous for the rail vehicle operator that there is no need to provide and maintain costly structural measures along the track (for example wind protection walls) or measures in the vehicle (for example the use of ballast to maximize the heel contact force in the driving bogie of the end car).