Process for detecting a derailment of a rail vehicle

Abstract

A process for detecting a derailment of a rail vehicle having two or more rail vehicle parts and one or more articulations through which adjacent rail vehicle parts are rotatably connected with one another includes determining an angle of rotation between adjacent rail vehicle parts, and/or a quantity derived from the angle of rotation. The process further includes comparing the angle of rotation or the derived quantity with at least one reference value or threshold, or with at least one reference value range or threshold range. A test criterion indicating whether or not there is a derailment is defined based on the at least one reference value or threshold, and/or an expected relationship of multiple angles of rotation, and/or an expected relationship of the multiple quantities derived from the angles of rotation, relative to one another. The method further includes determining whether or not the test criterion is met.

Claims

1. A process for detecting a derailment of a rail vehicle having two or more rail vehicle parts and one or more articulations through which adjacent rail vehicle parts are rotatably connected with one another, the process comprising: a) determining a-1) an angle of rotation between adjacent rail vehicle parts, and/or a quantity derived from the angle of rotation; or a-2) multiple angles of rotation or multiple quantities derived from the angles of rotation between different adjacent rail vehicle parts, b) comparing b-1) the angle of rotation or the derived quantity from a-1) or multiple angles of rotation or derived quantities from a-2) with at least one reference value or threshold, or with at least one reference value range or threshold range; and/or b-2) multiple angles of rotation or the multiple quantities from a-2) derived from the angles of rotation, relative to one another; and/or b-3) a state value that is determined from multiple angles of rotation or multiple quantities from a-2) derived from the angles of rotation with at least one reference value or threshold, or with at least one reference value range or threshold range, a test criterion indicating whether or not there is a derailment, this test criterion being defined based on: the at least one reference value or threshold, the reference value range, and/or the threshold range in b-1) or b-3), and/or an expected relationship of multiple angles of rotation, and/or an expected relationship of the multiple quantities from b-2) derived from the angles of rotation, relative to one another, and c) determining whether or not the test criterion is met and whether a derailment is happening or has happened, or is not happening or has not happened, wherein the threshold is an angle of rotation matching a minimum radius of a curve, and the test criterion is defined so that the angle of rotation is less than the threshold.

2. The process according to claim 1, wherein the derived quantity is a rotational angular velocity and/or a rotational angular acceleration.

3. The process according to claim 1, further having one or more of the following steps if it is found that the derailment is occurring or has occurred: producing a derailment situation signal if it has been determined that the derailment is occurring or has occurred; outputting a warning or a distress signal about the derailment; sending a message about the derailment to a control center or a rescue center; and emergency braking or other braking of the rail vehicle.

4. The process according to claim 1, wherein multiple angles of rotation or multiple quantities derived from these angles of rotation are determined at different articulations.

5. The process according to claim 1, wherein the at least one reference value or threshold and/or the reference value range or the threshold range are or have been determined from a reference run of the rail vehicle on an equal section of a track, or on a same section of the track.

6. The process according to claim 5, wherein value limits of the reference value range are defined as follows: an upper reference value, which corresponds to a value of an angle of rotation, determined during the reference run of the rail vehicle, or a quantity derived therefrom, plus a tolerance value, and lower reference value, which corresponds to the value of an angle of rotation determined during the reference run of the rail vehicle, or a quantity derived therefrom, minus a tolerance value, and wherein the test criterion is defined so that the determined angle of rotation, or the quantity derived from the determined angle of rotation lies within the reference value range.

7. The process according to claim 1, wherein the test criterion is defined so that the angle of rotation or the quantity derived therefrom is less than the reference value or threshold.

8. The process according to claim 1, wherein the process is carried out with positional resolution along the track.

9. The process according to claim 1, wherein the state value is a difference between at least two angles of rotation or between at least two quantities derived therefrom at successive or non-successive articulations.

10. The process according to claim 1, wherein value limits of the threshold range are defined as: an upper threshold, which corresponds to a value of a first articulation's angle of rotation or a quantity derived therefrom, determined at a place on the track during the run of the rail vehicle, plus a tolerance value, a lower threshold, which corresponds to a value of the first articulation's angle of rotation, or a quantity derived therefrom, determined at the place on the track during the run of the rail vehicle, minus a tolerance value, the test criterion being defined so that the determined angle of rotation, or the quantity derived therefrom, at a second articulation that follows the first articulation, lies within the threshold range, when the second articulation reaches this place on the track during the run of the rail vehicle.

11. The process according to claim 1, wherein the comparison of multiple angles of rotation or multiple quantities derived from the angles of rotation relative to one another involves determining whether the angles of rotation or the quantities derived therefrom have a same sign or a different sign.

12. The process according to claim 1, further comprising: determining a shape of a section of track in which the vehicle or one or more successive articulations are located.

13. The process according to claim 12, wherein the at least one reference value or threshold, the tolerance value, or a range thereof are adapted to the shape of the section of the track.

14. The process according to claim 1, wherein the at least one reference value or threshold, the tolerance value, or a range thereof are adapted to a travel speed.

15. A rail vehicle having an analysis device that is set up to carry out the process according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is described below on the basis of sample embodiments. The figures are as follows:

(2) FIG. 1: a rail vehicle in curved position;

(3) FIG. 2: a rail vehicle in straight position;

(4) FIG. 3: a rail vehicle in an S-curve; and

(5) FIG. 4: a process sequence.

(6) Quantities and reference numbers that are mentioned in the following examples can be found in the list of reference numbers at the end.

(7) FIG. 1 shows the rail vehicle 1 with railroad vehicle parts 2, 3, 4, 5, 6. The modules 2 and 6 are end modules of a streetcar, which In this case represents the rail vehicle. Bogies or chassis are labeled with the reference number 7. The rail vehicle 1 travels on rails 8.

(8) The railroad vehicle parts 2, 3, 4, 5, 6 have the articulations 10, 11, 12, 13 arranged between them. At each articulation an articulation angle α, β, γ, δ has been set.

(9) FIGS. 2 and 3 show the articulations with changed angular position; the same reference numbers are used as FIG. 1.

(10) The inventive process is explained below using sample criteria. The system recognizes “normal travel” and “derailment” on the basis of the criteria A, B, C, D, E, F, G, H, I, J listed below, which can be supplemented, as needed.

(11) A derailment can also be recognized if one or more of these criteria is/are no longer met. The criteria can be general criteria or run-specific criteria. The general criteria A through E can always apply. The additional criteria F through J can be specific for the travel scenarios described below.

(12) Criterion A:

(13) Travel is normal (i.e., free of derailment) if the articulation angle is less than the angle U matching the smallest radius in the rail network (based on geometric track data: radius of the curve)
|θ|<|θ.sub.max|+T
θ.sub.max can be recorded during a test run or it can be calculated from the radius and the overall dimensions of the vehicle or it can be measured.
Criterion B:

(14) A run is normal if the change in angle over time is less than the measurement of a reference run or a threshold. A Dirac-shaped change in angle is impossible in normal travel.
|θ′.sub.t|<D (where D is a realistic Dirac value, e.g., D=7°/s)
Criterion C:

(15) A run is normal when comparison of the current measurements with the results of a reference run shows that these current measurements remain within a tolerance. The tolerance takes into consideration the effect of speed and static and dynamic deviations . . . ).
θ=θ.sub.F±T
θ′.sub.t=θ′.sub.tF±T
Criterion D:

(16) A run is normal if the difference between two successive articulation angles is smaller at any time than a threshold U. The threshold can be recorded during a reference run or a conservative value can be assumed, e.g., 15°)
−U<|α(t.sub.0)|−|β(t.sub.0)|<U∀t.sub.0
Criterion E:

(17) A run is normal if a following articulation is deflected at the same position in the rail network as the preceding articulation (can be calculated from speed and overall dimensions of the vehicle)

(18) $a\left(t_0\right)-T<\beta \left(t_0+\frac{d}{v\left(t0\right)}\right)<\alpha \left(t_0\right)+T$
Criterion F:

(19) A run is normal if the changes in angle over time of successive articulations are the same at the same position in the rail network

(20) ${\alpha }_t^{\prime }\left(t_0\right)-T<{\beta }_t^{\prime }\left(t_0+\frac{d}{v\left(t0\right)}\right)<a_t^{\prime }\left(t_0\right)+T$

(21) The above-mentioned general criteria, which can always be set as valid in any combination or subcombination, can be supplemented by the following run-specific criteria.

(22) The following criteria are run-specific criteria:

(23) Scenario 1: Straight Track (with Reference to FIG. 2):

(24) A derailment is present on a straight track if one or more of the following criteria is/are not met:

(25) Criterion G:

(26) A run is normal if all articulations have no deflection
|θ(t)|<T (e.g., T=4°)
Criterion H:

(27) A run is normal if there is no angular velocity in the articulation
|θ′.sub.t|<T (e.g., T=3°/s)
Scenario 2: Constant Arc (with Reference to FIG. 1)

(28) Additional run-specific detection criterion:

(29) Criteria I:

(30) A run is normal when all articulations have the same deflection in the same direction (within a given tolerance):
α=β±T, β=γ±T, γ=δ±T (e.g., T=±4°)
Scenario 3: S-Curve (with Reference to FIG. 3):

(31) Additional run-specific detection criterion:

(32) Criterion J:

(33) The articulation 11 is located after the point of inflection W of the S-curve in the direction of travel F (that is, it has already passed the point of inflection), while the articulation 12 is still located before the point of inflection W. The successive articulations 11, 12 have opposite deflections (positive and negative).

(34) A run is normal if the absolute values of two articulation angles (e.g., |α| and |β|) do not simultaneously become greater (i.e., two modules cannot rotate in opposite directions in a normal S-curve).

(35) The following algorithm can then be used, for example:
IF(α*β<0) AND (α′.sub.t*β′.sub.t<0) THEN . . . criterion J is not met (i.e., derailment is detected)

(36) FIG. 4 is a process flow chart. The testing of criteria A-F is independent of the shape of the track. It is not necessary to test all criteria A-F, as is shown here, but rather it is also possible to test any selection of one or more of these criteria. If the criterion is met, a run is normal, e.g., free of derailment in this example. If the criterion is not met, there is a derailment. If multiple criteria are tested, there is redundant testing, and the yes/no result can be strengthened.

(37) The above-described criteria G, H, I, and J involve additionally testing, in another step, whether the vehicle or articulations that are being considered are located on a straight track (criteria G and H), whether they are located in a constant arc, or whether they are located in an S-curve. Here the shape of the track is tested by criterion C. That is, the angle of rotation or the rotational angular velocity is compared with measurements of the angle of rotation or the rotational angular velocity from a reference run on the same track, preferably at all articulations, and from this comparison it is possible to determine the current shape of the track. However, the shape of the track need not be determined on the basis of criterion C, but rather can also be done in another way, as previously indicated in the general description.

LIST OF REFERENCE NUMBERS

(38) 1 Railroad vehicle 2,3,4,5,6 Railroad vehicle part 7 Bogie 8 Rails 10,11,12,13 Articulations F Direction of travel W Point of inflection of an S-curve α,β,γ,δ Articulation angle (depends on the number of modules) θ Articulation angle in every articulation, general term for α,β,γ,δ . . . if the conditions are simultaneously satisfied for every articulation angle α′.sub.t, β′.sub.t, γ′.sub.t, δ′.sub.t, θ′.sub.t angular velocities

(39) ${\theta }_t^{\prime }\left(t_0\right)=\frac{\theta \left(t_0+\mathrm{.Math.}\right)-\theta \left(t_0\right)}{\mathrm{.Math.}}$ where the term ε in the above expression

(40) $\frac{\theta \left(t0+\mathrm{.Math.}\right)-\theta \left(t0\right)}{\mathrm{.Math.}}$
corresponds to the time sampling of the sensor. U Reference threshold T Tolerance t Time t.sub.0 Reference time point d Distance between articulations (module lengths) v(t.sub.0) instantaneous velocity of the vehicle F Subscript. Means that the value was determined in a reference run (e.g., α.sub.F, θ′.sub.tF . . . )