ES2252663T3 - PROCEDURE AND DEVICE FOR THE ON-BOARD DIAGNOSIS OF ELEMENTS GUIDE TO WHEEL ASSEMBLY. - Google Patents

Abstract

The invention relates to a method for monitoring and diagnosing the condition of wheelset guiding devices on railway vehicles and a device for carrying out said method. It is generally very difficult to determine whether wheelset guide bushes made of elastomeric materials are sufficiently sturdy for operation or what the (remaining) service life thereof is because there are hardly any reliable calculation methods to do so. Furthermore, monitoring by controlling the dimensions thereof is almost impossible in the mounted state thereof because said wheelset guide bushes are difficult to access due to the assembly layout thereof within the bogie. According to the inventive method, the condition of the wheelset guide bush particularly the play thereof is monitored by evaluating an acceleration signal that is measured in real time in the area of at least one wheelset bearing, whereupon a displacement signal is estimated from said acceleration signal by means of double integration after separating the mean value. The range of said displacement signal is then subjected to a monitoring process.

Description

Procedure and device for diagnosis on-board guide elements of the set of wheels.

The invention relates to a method for status diagnosis and monitoring of guidance devices for wheel assemblies on rail vehicles, as well as a device to carry out the procedure.

The supervision of the driving behavior of vehicles on rails during use usual, when registering and evaluating operational parameters that They represent walking behavior. Here it turned out especially advantageous to record the effect of the oscillations by acceleration sensors and guide the signals generated by said acceleration sensors to a diagnostic device integrated into the rail vehicle.

Document DE 196 11 775 proposes the comparison of acceleration spectra determined in relation to each site, with a "vibration profile" defined as normal of a section to be crossed by the vehicle on rails. But in in this case the individual components of the vehicle, but only the spectrum is studied together integral of all components. Also in document DE 195 02 870 the evaluation of an acceleration signal is limited referred to the entire chassis, in order to recognize an eventual derailment of the chassis.

From document DE 101 45 433 a known procedure, in which the behavior of acceleration of at least two device consoles stabilizers assigned to the car box of a vehicle on rails, when forming both acceleration values a coefficient of correlation, compare it with a nominal value and emit a signal of alarm when exceeding this one. The procedure takes advantage of the dynamics of chassis with respect to the box of the car and relates in an appropriate way the resulting accelerations there in the devices console  stabilizers on the right and left side of the wagon box. But this procedure was not suitable for monitoring the wheel set guide bushings due to the different chassis dynamics and wheel hub guide bush (including the type of placement of the sensors).

Document DE 199 53 677 reveals the application of a procedure to recognize derailment of a vehicle on rails, in which it is determined vertically to the direction of advance an acceleration of a constructive element which is directly or indirectly in contact with the trail, is measured the acceleration through acceleration sensors, a double integration over the period of time and finally it compares with an upper and / or lower limit value. It is in this case of a procedure, in which from an acceleration signal mean and a elimination of a linear tendency to be realized in the calculation framework, a travel difference is estimated. But the estimation accuracy of the travel signal that can achieved in this way, it is insufficient in its diagnostic quality for a coupling to a vehicle control.

The wheelset guide located in front of the bogies frame of the vehicle on rails represents a system component that supports a high demand, which So far I cannot register with the necessary quality by known diagnostic systems. In the current serial constructions for high-speed trains of the ICE family, the precise guide of the wheel assemblies is made through two guide pins placed under pressure in the bogies frame and bushings mounted on said spikes, or through guide bushings of wheel assemblies in the steering wheel to articulate the pivoting arm with the frame of the Bogies Regardless of the respective constructive solution, for guide assemblies of wheel assemblies are used elastomeric materials, whose composition of material and properties They are consistent with the purpose of use. In addition to achieving a march quiet vehicle is also important to have a limited possibility of radial adjustment of wheel assemblies when advancing in curves That way the wheel set guide bushings they are subject to daily use to multiple factors that produce wear. In vertical sense they are exposed to the forces of weight of the vehicle and dynamic forces from irregularities of the trail (eg grooves on the surface of the rails), in the horizontal longitudinal direction act braking forces and acceleration, in a transverse direction, centrifugal forces act at advance in curves In addition to these solicitations you can also add a slight rotation inside the bushing.

In general, it is very difficult to test in elastomer parts with sufficient wear resistance, or be able to indicate the useful life (remaining), given that There are safe calculation procedures. It is also not possible perform a monitoring by controlling the dimensions of guide bushings for wheel assemblies in the placed state, since they are barely accessible due to their place of placement in the Bogie

The invention, therefore, is based on the objective of developing a procedure for the diagnosis of status and monitoring of guiding devices for sets of wheels on rail vehicles, as well as a device for Carry out the procedure. A robust design and suitable for use railway must ensure a high quality of diagnosis and reliable alarm rates.

This objective is met according to the invention in relation to the main concept of claim 1 to monitor the condition of the guide bush for wheel assemblies of the vehicle on rails - especially its game - when evaluating a signal of acceleration currently measured in the area of at least one wheelman of set of wheels, when making from this signal of acceleration through double integration after release of the average value made in each case, an estimate of a signal travel. This estimated travel signal w (t) represents a magnitude of state that uniquely describes at least a coordinate of the current spatial location of the set of wheels in relation to the other components of the bogie that surround it. With a larger set of the wheel set guide bushing or also in case of rigidity modifications not allowed, in operating status is expected with respect to this coordinate spatial a significant change of location with respect to optimal state But in principle it seems impossible to make a deduction of such an estimate of the travel signal from of the starting signals of acceleration sensors, by means of a double integration, since neither the initial position nor neither the initial velocity of the measurement point. The task according the invention lies in indicating a procedure that despite this allow for proper location estimation and supervision space of the wheel set guide bushings.

According to a special embodiment of the object of the invention, from the signal estimates of path w (t) of at least two sets of wheels that form part of a vehicle bogie on rails, the measure is estimated of the distance of these wheel sets w_ {S, A} from each other (variant A). This procedure is especially advantageous because at the high significance of the determined signal and the high degree of fault recognition related to it. In this context it should be taken into account that when determining w_ {S, A} to the result, subtracts the default distance constructively w_ {A} static between the two wheel bearings of the wheel assemblies.

An advantageous modification of the idea of invention provides that from the estimation of the signal of travel w (t) of a set of wheels, the measurement is analyzed of the distance between this set of wheels and a fixed point on the corresponding bogie frame w_ {S, S} of the vehicle on rails (Variant B). In contrast to the embodiment before mentioned, not only the side of a bogie frame can be estimated affected by an irregularity in the wheel assembly guide, but also a clear identification of the pair of guide bushings of the wheel assembly that is specifically damaged. Also in this case, when determining W_ {S}, the result must subtract constructively predetermined distance w_ {A \ static} between the wheelman and the fixed point within the framework of the Bogies

Other preferred conformations of the procedure according to the invention result from the other characteristics indicated in subclaims 4 to 10.

According to the invention, the task is also solved. by means of a device with the characteristics mentioned in the claim 11. Since in at least one casing of the wheelman of the set of vehicle wheels on rails, there are elements to record the acceleration behavior of at least one guide sleeve of the wheel assembly, by means of which you can register a currently measured acceleration signal and submit to a monitor the distance w_ {S} of a travel signal w (t) estimated from this acceleration signal by double integration after the release of the average value made in each case, can be made available so advantageous a device for the diagnosis of status and the monitoring of guide devices for wheel assemblies in rail vehicles.

Especially it may have been planned in a way of preferred embodiment than an evaluation facility for the supervision of the estimated travel signal is an integral part of a top device implemented in the vehicle on rails for monitoring the running properties of the vehicle on rails That way another step is specified to achieve an efficient on-board diagnostic system integrated into vehicle.

The following explains in greater detail the idea of the invention by means of an embodiment with the corresponding Figure 1.

Figure 1 shows schematically (view of plant) a bogie frame (1), as well as two sets of wheels (2, 3), where the bogie framework is supported by a system of primary damping (not represented here for the purpose of increase clarity) and in each case two sets of bearings of wheels (4,5; 6,7) on the two sets of wheels. At immediate environment of a wheel assembly wheel in each case two guide assemblies of wheel assemblies.

In the first solution variant of the idea of the invention is monitored the measure w_ {S, A} between the two wheel sets For the estimation of W_ {A} two are required acceleration signals by the bogie, which come from sensors, which are mounted in the area of the guide bushings of wheel assemblies (4,5; 6,7) in at least two carcasses of wheelset wheel bearings, which have at least one direction of detection that runs parallel to the spatial coordinate to be studied. Therefore it governs:

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o

\hskip0.5cm

bien,

\hskip0.5cm

w_{A}(t)= w_{5}(t) - w_{7}(t)w_ {A} (t) = w_ {4} (t) - w_ {6} (t)

 \ hskip0.5cm 

or

 \ hskip0.5cm 

good,

 \ hskip0.5cm 

w_ {A} (t) = w_ {5} (t) - w_ {7} (t)

In order to simplify, from now on part of the base that the spatial coordinate to be examined matches  with the direction of advancement of the vehicle on rails. Given the then there is a fixed allocation between the guide bushings of the wheel assemblies and the acceleration sensor, for the purpose of simplification the same references are used in Figure 1 for both.

In the modified solution variant according with claim 3, the distance measurement is monitored w_ {S} between a wheel assembly (2) and a fixed point (8) in the corresponding bogie frame (1).

The vehicle on rails (not shown) includes a system of data recording and evaluation that is connected to the acceleration sensors. The evaluation unit of the vehicle on rails controls the warning notices for the driver of the locomotive vehicle and / or error messages to operating systems and / or actors to act on the command of vehicle. The construction and mode of action of such systems of data logging and evaluation are also general knowledge like acceleration sensors and they are not explained in greater detail in this context.

Through the acceleration sensors is recorded the acceleration of the wheel assemblies (2, 3) in the sense of progress Of the signals determined here must then conclude the spatial location of the wheel assemblies in the guide bushings for wheel assemblies (4, 5; 6, 7). During the vehicle running on rails in the direction of travel, the wheel sets present at different times each time different distances w_ {A} from each other.

Since the spatial coordinate of a set of Wheels to be studied, usually presents limit values upper and lower, should be based on the base that corresponding travel measurement quantities range in a interval around a resting position. Considering additionally the linear character of an integrated constant and the Square curve shape of an integrated line concludes that at have a series of measurement data with an average value different from zero, both the first and the second curve of integration have infinity. This can be avoided by releasing the average value signals prior to an integration.

For the estimation of the speed and travel signals from the acceleration signal measured a , the following applies:

(one)

the Dynamic travel signal has an average value close to zero for a sufficiently long period,

the data section studied in each case includes an amount sufficient periods of the signal path components dissociated according to the Fourier series, with the least frequency to be Taken into account.

The estimate (1) is usually found compulsorily completed by construction and frequently it occurs in machine oscillations, especially when machines They are in a stable operating state. The estimate (2) governs when the signal of interest travel oscillates with high frequency, or has more frequency ratios high. Each travel signal of a typical machine swing can be represented in practical form as the sum of theoretically Infinite sine and cosine functions (Fourier series):

w (t) = \ frac {\ alpha_ {0}} {2} + \ sum \ limits ^ {\ infty} _ {k = 1} (\ alpha_ {k} \ cdot cos (2 \ pi \ cdot k \ cdot f \ cdot t) + \ beta_ {k} \ cdot sen (2 \ pi \ cdot k \ cdot f \ cdot t))

where:

f = basic frequency

α, β = fourier coefficient

Since the travel signal w (t) to be estimated oscillates around a resting position and presents a mean value of zero, the term can be set aside \ frac {\ alpha_ {0}} {2}.

In addition there are still errors due to the data indicator window, which are compensated through all frequencies in general consideration and from the point Statistical view tend to an average value of zero.

\;

y

\;

\frac{\delta}{\delta t} cos(t) = -sen(t) por lo tanto también rige, que las señales de velocidad, o bien, aceleración determinadas por diferenciación (doble) de la señal de recorrido w(t) representada como serie Fourier, presentan en cada caso un valor medio que aproximadamente es cero.With \ frac {\ delta} {\ delta t} sin (t) = cos (t)

 \; 

Y

 \; 

\ frac {\ delta} {\ delta t} cos (t) = -sen (t) therefore also governs that the speed signals, or acceleration determined by differentiation (double) of the travel signal w ( t) represented as Fourier series, in each case they have an average value that is approximately zero.

The speed signal v (t) for a Time window chosen, results as follows from the acceleration:

       \ vskip1.000000 \ baselineskip
    

10

       \ vskip1.000000 \ baselineskip
    

where

       \ newpage
    

v

= speed,

v_ {0}

= speed at time t_ {0},

to

= acceleration

t

= time

\ Deltat

= period between two detections

i

= index of measurement points

n

= number of measuring points in the section of data

Since the average value of v must adopt the zero value, governs:

eleven

This means that by integration and subsequent release of the average value v_ {0} can be compensated partially. In this way it is possible to determine the signal of speed with a calculable error limit.

Similarly, it is determined according to the invention. the travel signal from the speed signal.

Unlike the above, it should be taken into account when determining the magnitude of the path w_ {B} (variant B) that in this case, that is to say when considering the relative section between the wheel set wheelman and bogie frame, can dispense with a first approach of the acceleration signal a_ {d} -which can be used as a reference- of the bogie framework. Could prove that the magnitude of difference a_ {r} / a_ {d} depends essentially a_ {r}, given that the ratio of the amplitudes a_ {r} / a_ {d} adopts high values (eg 50 and higher).

Where:

a_ {d} = bogie acceleration signal

a_ {r} = acceleration signal of the set of wheels

The accelerations under the bogie are remarkably inferior and are also dominated by parts of low frequency This specific oscillation phenomenon can then be used in such a way that the signal a is released from the linear trend and offset, and the resulting signal - assuming a sufficiently short period of time - you can be used as a good approximation for the magnitude of difference a_ {r} - a_ {d}.

The development of signal processing is as follows: the sensors in the area of the bearings of the rollers of the wheelset ([4 and 5], or [6 and 7]) provide the necessary acceleration signals as initial magnitude. So preferred all data processing steps are performed in a data window length of 2 seconds.

In variant A in each case they subtract each other synchronously over time, the two acceleration signals of one side of the bogie after the release of the average value of each individual signal, and the value of the different one is submitted then to other data processing steps: after filtered, a first integration, new release of the average value and second integration the measure is determined next w_ {S, A} desired of the estimated travel signal w_ {A}, and is stored in a buffer. After having calculated and provisionally stored a sufficient amount of values of distance, the average value is formed from it. This is used then in the vehicle data recording and evaluation system on rails as a magnitude of online supervision and compared in continuously with a fixed limit value determined within the framework of The parameterization. Within the framework of the tests it was appropriate to use an average value that varies in the range of the 30 most current distance values. For this, the oldest distance value in each case by the last value of distance calculated when a data window is succeeded. That way a pairing of the magnitude of supervision, thus minimizing the false alarm rate through a more significant setting of the limit value. The diagnostic depth that can be achieved in variant A is limited to the side of the bogie (in the direction of advance to the left, or well, right), but no damage can be assigned to a wheel.

Unlike this, in variant B, dispenses with the subtraction of two acceleration signals, due to to processing, or use of an acceleration signal in each case. The depth of diagnosis here includes recognition of defective guide bushings in the wheel area.

When evaluating the average value should be considered In addition, the magnitude of supervision also presents variations in a GOOD state that has no errors, which are due to Elastic travel of the wheel set guide bushing. In DEFECTIVE state this wheel set guide set increased by the error, it cancels the system's own basic game. Experimentally it was shown that this discrepancy, or, overlap can only be checked significantly at a speed that exceeds the minimum. So, for example, with a tour elastic from 0.3 to 0.5 mm a minimum speed of 120 was necessary km / h

A suitable subsequent conformation of the variant B of the invention according to claim 5 provides that by automatic selection of features, for example, using SVM (Support Vector Machine) a selection of additional features, which is dependent on the speed of Advance. By taking advantage of other features you can offset the lower significance of the characteristic w_ {B} supervised, caused by the application of approach solutions in case of difference formation and double integration. But it remained demonstrated in numerous series of trials, that the result of the Automatic feature selection depends largely on the forward speed area inspected, as well as the duration of mediation. Therefore, it was advisable to proceed in stepped forward speed areas with features specific additional in each case. The recognition rate of  errors increases here with a tendency to longer periods of mediation and narrower speed areas.

Reference List

w (t) travel signal Dear w_ {I} travel signal in the wheel assembly guide bushing site I w_ {S} signal distance covered travel w (t) w_ {A} distance between the wheel assemblies of a bogie w_ {B} distance between the set of wheels and the fixed point under the bogie one bogie frame 2, 3 wheel set 4, 5, 6, 7 wheel set guide bushing, or sensor acceleration 8 fixed point under the bogie

Claims (12)

1. Procedure for the diagnosis of the state and monitoring of guide devices for wheel assemblies in rail vehicles, characterized because the condition of the guide bushing is monitored for wheel assemblies (4, 5, 6, 7) of the vehicle on rails -especially his game- when evaluating an acceleration signal currently measured in the area of at least one assembly wheelman wheels, when making from this acceleration signal by double integration after the release of the average value made in each case, an estimate of a travel signal w (t) representing a magnitude of state that describes uniquely at least one coordinate of the current spatial location of the wheel assembly (2, 3) in relation to the other components from the bogie that surround him. 2. Procedure for the diagnosis of the status and supervision of guide devices for wheel assemblies in rail vehicles according to claim 1, characterized in that from the estimates of the travel signal w (t) of at least two sets of Wheels (2, 3) that are part of a vehicle's bogie on rails, the measure of the distance of these wheel sets w_ {S, A} from each other is estimated. 3. Procedure for the diagnosis of the status and supervision of guide devices for wheel assemblies in rail vehicles according to claim 1, characterized in that from the estimation of the travel signal w (t) of a wheel assembly (2), the measure of the distance w_ {S, B} between this set of wheels and a fixed point (8) in the corresponding bogie frame (1) of the vehicle on rails is determined. 4. Procedure for the diagnosis of the status and supervision of guide devices for wheel assemblies in rail vehicles according to claim 3 characterized in that linear trends are eliminated from the acceleration signal and the offset of starting and braking processes of the vehicle on rails. 5. Procedure for the diagnosis of the status and supervision of guide devices for wheel assemblies in rail vehicles according to at least one of claims 3 or 4 characterized in that by means of an automatic selection of characteristics a selection of additional characteristics is made, It depends on the speed of advance. 6. Procedure for diagnosing the condition and monitoring of guide devices for wheel assemblies in rail vehicles according to at least one of claims 1 to 5 characterized in that the evaluation of the acceleration signal with double integration is carried out within a preferred integration interval \ Deltat = 2 seconds. 7. Procedure for diagnosing the condition and monitoring of guide devices for wheel assemblies in rail vehicles according to at least one of claims 1 to 6 characterized in that the integration intervals \ Deltat_ {i} \ Deltat_ {i + 1} begin sequentially depending on each other. 8. Procedure for diagnosing the condition and monitoring of guide devices for wheel assemblies in rail vehicles according to at least one of claims 1 to 7, characterized in that from several distances w_ {S, i} (t) of the travel signals w_ {i} (t), determined by double integration of the acceleration signal through the integration intervals \ Deltat_ {i} that run sequentially, mean values are formed which are compared continuously or in predetermined time intervals with a certain limit value within the framework of the parameterization, and because related to exceeding these predefined limit values, alarm procedures are initiated. 9. Procedure for the diagnosis of the condition and supervision of guide devices for wheel assemblies in rail vehicles according to at least one of claims 1 to 8 characterized in that the diagnostic procedure is activated only from a minimum speed of rail vehicle 10. Procedure for the diagnosis of the condition and supervision of guide devices for wheel assemblies in rail vehicles according to at least one of claims 1 to 9 characterized in that the procedure is applied as an integral component of a superior procedure implemented in the vehicle on rails for diagnosis and supervision of the running properties of the vehicle on rails. 11. Procedure for status diagnosis and monitoring of guide devices for wheel assemblies in rail vehicles, characterized because there are elements to register the acceleration behavior of at least one guide sleeve of the set of wheels (4, 5, 6, 7), by which you can register a currently measured acceleration signal and submit to a supervision with respect to exceeding the limit value, the distance of an estimated travel signal from this signal acceleration through double integration after release of the average value made in each case. 12. Procedure for the diagnosis of the status and supervision of guide devices for wheel assemblies in rail vehicles according to claim 11 characterized in that an evaluation system for monitoring the travel signal is an integral component of a superior device implemented in the vehicle on rails, for the supervision of the running properties of the vehicle on rails.