This application claims the priority, under 35 U.S.C. ยง119, of German application DE 10 2005 039 420.5, filed Aug. 16, 2005; the prior application is herewith incorporated by reference in its entirety.
The invention relates to a railroad system and to a method for determination of information about a railroad system. The railroad system has at least one track, which is formed from at least two rails, on which railroad vehicles move along the rails. The system further has a device which is electrically connected to the two rails at a connecting point and which injects an electric current into the rails. The invention also pertains to a method for determining information, in particular about a broken rail, in the railroad system.
Railroad systems are generally known, for example for passenger trains. These generally have a plurality of tracks, which are formed from two rails. Signals to control the trains are arranged along the tracks. The signals are driven by safety devices, with respectively adjacent safety devices interchanging control information. This interchange takes place via the rails by means of coded data in the form of electrical current pulses, for which purpose the safety devices are electrically connected to the two rails.
Furthermore, U.S. Pat. No. 5,769,364 discloses a diagnosis device in which two devices, in particular safety devices, interchange information in the form of pulses via the rails, with the two devices alternately transmitting and receiving the information. In this case, the voltage which is applied to the two rails by the one device, the current which is produced by it and the voltage which results from it at the other device are in each case measured. These measurements are used to determine whether the rails are broken.
One disadvantage in this case is the relatively high degree of complexity and the lack of any capability to localize the broken rail.
It is accordingly an object of the invention to provide a railroad system and a method for determination of information about the railroad system, which overcomes the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and, by means of which the information can be determined with little complexity, in particular the information about the location of a broken rail and/or the direction of travel of a railroad vehicle.
With the foregoing and other objects in view there is provided, in accordance with the invention, a railroad system, comprising:
a track formed of at least two rails configured to support railroad vehicles moving thereon;
a device electrically connected to the rails at a connecting point and configured to inject an electric current into the rails;
means associated with the device for detecting a profile of the current or a corresponding profile of an effective track impedance while a railroad vehicle is approaching the connecting point, passing the connecting point, and moving away from the connecting point; and
means associated with the detecting means for deriving at least one railroad system information item on the basis of the profile.
In accordance with a further feature of the invention, the deriving means is configured to determine a broken rail on the basis of the profile.
With the above and other objects in view there is also provided, in accordance with the invention, a method of determining information in a railroad system having a track formed with at least two rails and having railroad vehicles moving along the rails. The method comprises:
providing a device with an electrical connection to a connecting point at the rails of the track;
injecting an electric current into the rails at the connecting point;
detecting a profile of the current, or a corresponding profile of an effective track impedance, while a railroad vehicle is approaching the connecting point, passing the connecting point, and moving away from the connecting point; and
deriving at least one railroad system information item on the basis of the profile.
In other words, with regard to the railroad system and with regard to the method, the solution provides for the profile of the current or the corresponding profile of the effective track impedance to be detected, while a railroad vehicle is approaching the connecting point, passes it and moves away from it again, and for at least one railroad system information item to be derived on the basis of the profile.
In accordance with an added feature of the invention, the railroad system information item is at least one of a state of the track and a direction of travel of the railroad vehicle. In accordance with another feature of the invention, deriving means is configured to determine the state of the track state on the basis of noticeable rates of change of the profile. The changes are considered noticeable when they are outside a predetermined tolerance band. In the alternative, or in addition, the changes are considered noticeable when they exceed a predetermined value within a predetermined time interval.
In other words, the railroad system information preferably includes the track state and/or the direction of travel of the railroad vehicle.
It is technically simple for the track state to be derived on the basis of noticeable rates of change of the profile.
One simple criterion for noticeable changes is when the changes are outside a predetermined tolerance band.
Simple noticeable changes occur when they exceed a predetermined value within a predetermined time interval.
In the simplest case, a broken rail can be determined on the basis of the profile.
The location of the broken rail is determined with little effort on the basis of the profile.
In order to form a reference value with little effort, it is proposed that the profile in the area of the connecting point have an essentially constant value as a maximum value, and for this constant value to be used as a reference value.
The accuracy can be increased if the device is arranged in the area, or in the vicinity of an isolating abutment of the rails.
In order to make integration in existing railroad systems easier, it is proposed that the device transmit electrical current pulses via the rails, and that the profile correspond to the amplitudes of the current pulses in the form of an envelope curve.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a railroad system and method for determination of information about a railroad system, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
Referring now to the figures of the drawing in detail and first, particularly, to
A schematically illustrated railroad vehicle 3 is moving along the rails in the direction of the arrow 4. Only two wheels 6 of the railroad vehicle 3 are illustrated in
With reference to
On the basis of Ohm's law, the profile 10 of the current I corresponds closely with the profile 10 of the effective track impedance.
The profile 10 can be used to obtain information (railroad system information) as to the direction of travel in which the railroad vehicle 3 is moving.
The breakage of one of the rails 2 virtually always occurs only when a railroad vehicle 3 is moving over the rails 2, so that at least one wheel axle 5 will always have passed over the broken point in the direction of the connecting point 7. In a corresponding manner, the profile 10 shown in
There should expediently be two devices 8, arranged in the area of the abutment points 9a, 9b, because of the asymmetry (see
A noticeable change in the current I also occurs when a change exceeds a predetermined value within a predetermined time interval. A profile that has been normalized with respect to the current IK can also be used for evaluation purposes, with the current IK expediently being used as a reference value at the same time.
Only two of these current pulses IP are illustrated schematically in
The current pulses IP may, of course, be not only current pulses IP of coded data which are present in any case, but also general current pulses IP which are designed such that it is possible to determine the track impedance on the basis of the profile 10 or of the envelope curve.
Number | Date | Country | Kind |
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10 2005 039 420.5 | Aug 2005 | DE | national |