EP1003661B1 - Method for curve recognition and axle alignment in rail vehicles - Google Patents

Abstract

The invention relates to a method for measuring the curvature of a track for a running gear for rail vehicles and a method for aligning in a steering manner and in accordance with the curvature of the track an axle of a rail vehicle, which axle is rotationally mounted on a running gear frame. The track curvature is calculated by dividing a yaw velocity by a forward velocity and the wheels are aligned in accordance with a specified steering angle (ηsoll) which is calculated by multiplying the track curvature (χ) by half the distance (b) between the two axles (12, 13) of the running gear (10).

Description

The invention relates to a method for measuring a track curvature in a chassis for rail vehicles, and a method for directing a direction of rotation A chassis frame mounted axle of a rail chassis after the Track curvature.

In particular, in local transport are mainly rail vehicles with biaxial Chassis used. This narrow curves, often through the course of the road are given, to a poor cornering of multi-axle suspensions. This is mainly observed in rail vehicles whose wheels in terms their yaw motion are rigidly connected to the chassis frame.

A solution to this problem is achieved in that the axle or the wheels steerable are stored in the chassis frame. By a device for aligning the axis or the wheels can be a steering movement corresponding to the track curvature.

From DE 195 38 379 C1 is a two-wheeled chassis with single-wheel drive for track-guided vehicles with controlled steering known in which the chassis per Wheel carrier two each located outside the wheel contact points vertical Has pivot axes, wherein alternately - while locking the position of the current bow-shaped swivel axis - the wheel carrier to exactly this locked axis is pivoted.

From DE 92 19 042 U1 a method for curve recognition is known, which is the Track curvature determined by Indukivtaster.

Furthermore, methods are known in which the steering of the Wheels or axles passively. This can be done either by the Tracking forces or by a mechanical coupling of the Axle position with the angle of rotation between the car bodies respectively. However, these mechanical solutions have the disadvantage that they only allow a very inaccurate steering.

An exact alignment, however, is only possible if the axis active, e.g. with a servo drive, is set. The Control of the steering angle, the relative angle between wheel or axle and chassis frame, requires the default a steering angle setpoint. For determination of the steering angle setpoint In turn, knowledge of the track curvature is required.

The object of the present invention is to provide a method for Measurement of track curvature for rail vehicles to create using this value, the setpoint for the steering angle control to calculate.

The problem is solved by the features of claims 1 and 4, i.a. in that the track curvature from the division of a Yaw rate calculated by a translation speed and the wheels are aligned to a desired steering angle be multiplied by the so calculated Track curvature with half the distance between the two axes of the landing gear is calculated.

Fig. 1

das Verhältnis der Translations- und der Giergeschwindigkeit in Abhängigkeit von der Krümmung der Schiene;

Fig. 2

die Abhängigkeit der idealen Winkelstellung der Achse von der Kurvenkrümmung;

Fig. 3

den Krümmungsverlauf an der Hinterachse im Vergleich zu der Näherung durch das Meßverfahren beim Durchfahren einer Gleiskrümmung;

Fig. 4

den idealen Lenkwinkelverlauf (γ _ideal) im Vergleich mit dem berechneten Soll-Lenkwinkel (γ _soll);

Fig. 5

den idealen Lenkwinkelverlauf (γ _ideal) im Vergleich mit dem berechneten Soll-Lenkwinkel (γ _soll) nach der Filterung der Giergeschwindigkeit (Ω);

Further advantageous measures are described in the subclaims. The invention is illustrated in the accompanying drawings and will be described in more detail below; it shows:

Fig. 1

the ratio of translational and yaw rates as a function of the curvature of the rail;

Fig. 2

the dependence of the ideal angular position of the axis on the curve curvature;

Fig. 3

the curvature of the rear axle compared to the approximation by the measurement method when passing through a track curvature;

Fig. 4

the ideal steering angle curve (γ _ideal ) in comparison with the calculated target steering angle (γ _soll );

Fig. 5

the ideal steering angle course (γ _ideal ) in comparison with the calculated target steering angle (γ _soll ) after filtering the yaw rate (Ω);

Figures 1 and 2 show a chassis 10 for a non-illustrated Rail vehicle with axles 12 and 13 to which wheels 16 are attached. The axis 12 and 13 are mounted in the chassis 10. The chassis 10 and the axles 12 and 13 are rotatably supported by a centrally arranged joint 15.

The chassis 10 is shown while at a translation speed v a Track 11 passes through, which has a radius R. With the help of means that the Yaw rate Ω can determine the radius R or the track curvature χ be calculated. The track curvature χ corresponds to the reciprocal of the radius R. The division of the yaw rate Ω by the translation velocity v gives the Track curvature χ, according to the equation shown in Figure 1. The result The value of the track curvature χ is used to steer the axles 12 and 13, respectively. The relationship between the real and calculated track curvature χ can the figure 3 be removed.

The yaw rate Ω is preferably by a non-illustrated Rate of rotation or gyroscope sensor determined, for example, from navigation technology is known.

Since the distance between the wheel flanges of the wheels 16 of an axle 12 and 13 something smaller than the distance between the rails 17, the position of the axis may be in the Move the track channel laterally by a few millimeters. Thus, power surges, because of the often not exact track guide act on the chassis 10, lead to yaw. However, these oscillating movements have an effect on the measured values of the gyroscope sensor not insignificant influence. To eliminate the effect of commuting yaw of the undercarriage in the track, the measured value of the yaw rate Ω by means of a - is not smoothed - low pass filter smoothed. The effect of the low-pass filter when driving through of a track curve is shown in Figure 5.

The alignment of the axles 12 and 13 takes place with the aid of the track curvature so thus calculated. The track curvature χ serves to determine the desired steering angle γ _soll according to which the axles 12 and 13 are corrected. The adjustment of the axes 12 and 13 can be done for example by a servo motor.

The sine of the desired steering angle γ _{soll of} the - not shown - controller system is calculated by multiplying the track curvature χ with the half distance b between the axes 12 and 13, according to the equation in Figure 2.

This results in two approximations during cornering. The first approximation states that for an exact setpoint calculation at the bend entry both the curvature course at the front axle 12 and at the rear axle 13 would have to be known, however, only a value between them is measured due to the chassis rotation, as FIG. 3 shows. In addition, an approximation in the steering angle calculation during the curve run-in, since the geometric relationship of Figure 2 is only exactly correct when both axes 12 and 13 are in the curve, the two approximations are essentially canceled, so that the calculated target Value γ _{should ideally} match the ideal steering angle γ, as FIG. 4 shows.

If a rail vehicle has several running gears 10, then only the desired steering angle γ _{soll 1} for the foremost running gear in the direction of travel must be determined. The other chassis can take over this target steering angle offset in time. The target steering angle γ _{should be 1 + i} for the following in the direction of travel undercarriages are calculated by time delays .DELTA.t from the first target steering angle γ _{soll 1} . The delay .DELTA.t results from the division of the distance a _{i of} the trailing chassis i to the first chassis by the translation speed v.

reference numeral

10

Rail vehicle chassis

11

track curvature

12

Axle, front

13

Axle, rear

15

joint

16

wheel

17

rail

χ

track curvature

Ω

yaw rate

v

translational speed

R

radius of curvature

γ _should

Target steering angle

γ _ideal

Ideal steering angle

b

Distance between the axes

.delta.t

delay

a _i

Distance between the 1st and the i-th chassis

Claims (6)

1. A method for measuring rail curvature in an undercarriage structure for rail vehicles, characterised in that the rail curvature (χ) is calculated by dividing the yaw rate (Ω) by the translatory rate (v).
2. The method according to claim 1, characterised in that the measured value of yaw rate (Ω) is smoothed using a low pass filter to eliminate the effect of the alternating yaw movement of the undercarriage structure in the track channel.
3. The method according to either of claims 1 or 2, characterised in that the yaw rate (Ω) is determined by an angular rate sensor or gyroscopic sensor.
4. A method for steered orientation of wheels attached rotatably to an undercarriage structure of a rail vehicle in a curved track, characterised in that the wheels are steered according to a target steering angle (γ_soll) that is calculated by multiplying the rail curvature (χ) by half the distance (b) between the two axles of the undercarriage structure, the rail curvature (χ) being determined by a method according to any one of claims 1 to 3.
5. The method according to claim 4, characterised in that, in order to steer a plurality of undercarriage structures, only the rail curvature (χ) and the target steering angle (γ_{soll 1}) are determined for the leading undercarriage structure, whereas the target steering angles (γ_{soll 1 + i}) for the undercarriage structures following in the direction of travel are calculated from the first target steering angle (γ_{soll 1}) by temporal delaying (Δt).
6. The method according to claim 5, characterised in that the delay is yielded by Δt = a_i /v, where a_i is the distance between the following undercarriage structure and the first undercarriage structure, and v is the translatory speed.

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