Title:
Position adjustment of a vehicle car body
Kind Code:
A1


Abstract:
The invention relates to the position adjustment of a car body (1) of a track-guided vehicle, particularly of a rail vehicle, with regard to at least one undercarriage (5) of the vehicle. To this end, a transversal acceleration of the car body (1) transversal to a car body longitudinal axis is determined and a transversal position of the car body (1) with regard to the at least one undercarriage (5) is adjusted according to the determined transversal acceleration. A first transversal acceleration of the car body (1) in a first transverse direction transversal to the car body longitudinal axis and a second transversal acceleration of the car body (1) in a second transverse direction transversal to the car body longitudinal axis and transversal to the first transverse direction are determined.



Inventors:
Streiter, Ralph (Stuttgart, DE)
Application Number:
10/496503
Publication Date:
04/28/2005
Filing Date:
11/12/2002
Assignee:
STREITER RALPH
Primary Class:
International Classes:
B61F5/24; B60G17/019; B61F5/22; (IPC1-7): B61F1/00
View Patent Images:
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Primary Examiner:
MCCARRY JR, ROBERT J
Attorney, Agent or Firm:
HOYNG ROKH MONEGIER B.V. (Amsterdam, NL)
Claims:
1. A device for the position adjustment of a car body (1) of a track-guided vehicle, in particular a rail vehicle, with regard to at least one undercarriage (5) of the vehicle, with at least one actuator (7) for the adjustment of a transversal position of the car body (1) relative to the undercarriage (5) transversal to a car body longitudinal axis, a transversal acceleration measuring device for determining the transversal acceleration of the car body (1) and an adjustment device (20) for the adjustment of the relative transversal position of the car body (1) as a function of the measured transversal acceleration of the car body (I), whereby the transversal acceleration measuring device is connected to the adjustment device (20) and whereby the adjustment device (20) is connected to the actuator (7), characterised in that the transversal acceleration measuring device exhibits a first transversal acceleration sensor for the measurement of the transversal acceleration of the car body (1), which measures the transversal acceleration in a first transversal direction transversal to the car body longitudinal axis, and that the transversal acceleration measuring device exhibits a second transversal acceleration sensor for the measurement of the transversal acceleration of the car body (1), which measures the transversal acceleration in a second transversal direction transversal to the car body longitudinal axis and transversal to the first transversal direction.

2. The device according to claim 1, with at least two transversal acceleration measuring devices, for the measurement of the transversal acceleration at different points in the longitudinal direction of the car body (1).

3. The device according to claim 1, with a position measuring device for the measurement of a position of the car body (I) with regard to at least one undercarriage (5), whereby the position measuring device exhibits means for the measurement of the relative position in relation to two degrees of freedom for movements transversal to the car body longitudinal axis.

4. The device according to claim 3, whereby the position measuring device exhibits a first transversal position sensor for the measurement of the relative transversal position of the car body (1), which measures the transversal position in a first transversal direction transversal to the car body longitudinal axis, and whereby the position measuring device exhibits a second transversal position sensor for the measurement of the relative transversal position of the car body (1), which measures the transversal position in a second transversal direction transversal to the car body longitudinal axis and transversal to the first transversal direction.

5. The device according to claim 3, with at least two position measuring devices for the measurement of the relative position at different places and/or in different areas in the longitudinal direction of the car body (1).

6. The device according to claim 1, whereby the minimum of one actuator (7) exhibits a hydro-pneumatic device, with A container (51), which exhibits a diaphragm (57) separating a chamber (53) containing gas and a chamber (55) containing fluid, and a choke (63), which chokes a volume flow into and/or out of the chamber (55) containing the fluid from and/or to a storage vessel.

7. The device according to claim 1, whereby the device exhibits a first actuator (7) and a second actuator (7), whereby the actuators (7) are aligned and arranged in such a way that they can change the transversal position of the car body (1) in a common transversal direction, whereby the actuators (7) are in each case antagonistically actuatable by the application of an operating pressure and whereby the device exhibits means for the adjustment and/or delimitation of the sum of the operating pressures.

8. A method for the position adjustment of a car body (1) of a track-guided vehicle, in particular a rail vehicle, with regard to at least one undercarriage (5) of the vehicle, whereby A transversal acceleration of the car body (1) transversal to a car body longitudinal axis is determined, and depending on the transversal acceleration, a transversal position of the car body (1) with regard to the minimum of one undercarriage (5) is adjusted, characterised in that a first transversal acceleration of the car body (1) is determined in a first transversal direction transversal to the car body longitudinal axis and a second transversal acceleration of the car body (I) is determined in a second transversal direction transversal to the car body longitudinal axis and transversal to the first transversal direction.

9. The method according to claim 8, whereby the second and/or at least a higher temporal derivation of the first and/or second transversal acceleration of the car body (1) is formed, and, dependant on this, the transversal position of the car body (1) is adjusted.

10. The method according to claim 8, whereby the first and/or second transversal acceleration of the car body (1) is determined for at least two different places and/or areas in the longitudinal direction of the car body (1), and, dependent on this, the relative transversal position of the car body (1) is adjusted at two different positions in the longitudinal position of the car body (1).

11. The method according to claim 10, whereby, from the determined values of the transversal accelerations of the car body (1), at the minimum of two different places, a turn acceleration of the car body (1) about a high axis is calculated.

12. The method according to claim 10, whereby, from the determined values of the transversal accelerations of the car body (I), at the minimum of two different places and/or areas, the first and/or at least one higher temporal derivation of a turn acceleration of the car body (1) about a high axis is calculated, and, dependent on this, the relative transversal position is adjusted at two different places in the longitudinal direction of the car body (1).

13. The method according to claim 8, whereby, with regard to the relative transversal position of the car body (1), frequency ranges are considered and influenced with a frequency less than or equal to 10 Hz, in particular less than or equal to 7 Hz.

14. The method according to claim 8, whereby, with regard to the relative transversal position of the car body (1), frequency ranges are considered and influenced with a frequency less than or equal to 4 Hz, in particular less than or equal to 2 Hz, and whereby the transversal acceleration of the car body (1) is evaluated in a frequency range with a higher frequency and is taken into consideration during the adjustment of the relative transversal position.

15. The method according to claim 1, whereby, during a determination of a manipulated variable for the adjustment of the relative transversal position of the car body (1), at least one characteristic of the movement behaviour of the car body (1) is taken into consideration, in particular a characteristic for the excitation of oscillations of the car body (1), and whereby, by repeated evaluation of measured values and by temporal extrapolation of the movement behaviour of the car body (1), a possible future movement state of the car body (1) is calculated and taken into consideration in the determination of the manipulated variable.

Description:

The invention relates to a device and a method for the position adjustment of a car body of a track-guided vehicle, particularly of a rail vehicle, with regard to at least one undercarriage of the vehicle.

During the operation of rail vehicles, as a result of irregularities and defects in the rail alignment and rail position, undesirable transversal movements occur, which are detected as disturbing by passengers in particular. With undercarriages with conventional passive spring and damping systems, when travelling around a curve this leads to further deterioration in comfort, because the car body is displaced outwards transversal to the direction of travel or its longitudinal direction respectively, and the transversal suspension is therefore working in an area with higher spring rigidity.

To overcome these disadvantages with purely passive devices, active and adjustable systems have been proposed which counteract the transversal displacement. Known positioning devices, which are located between the undercarriage and the car body, exert a force on the car body which takes effect laterally during travel around bends in a track, which move it in the direction of the middle position in relation to the undercarriage. As a result, the full spring travel of the transversal suspension is again available, and stop elements on side buffer elements which delimit the transversal travel available are largely avoided. In order to achieve a high transversal elasticity of the coupling between the undercarriage and the car body, pneumatic actuators with high elasticity are used as positioning devices, for example. A disadvantage here is a large structural volume.

From DE-OS 20 40 922 the principle is known of regulating the position of a car body in relation to two undercarriages arranged on the end side in the direction of travel. In this situation, transversal acceleration sensors in the end areas of the car body detect the transversal acceleration values and, depending on these values, actuators control the relative position of the car body in relation to the undercarriages.

A problem of the invention is to increase the travel comfort.

The present invention is based on the knowledge that it is not sufficient, for a high degree of travel comfort, for only the transversal acceleration of a car body to be detected in one single direction and, depending on this, for the transversal position of the car body to be adjusted relative to an undercarriage. If the car body undergoes a transversal acceleration in an approximately horizontal direction, as a result of a fault in the track position, for example, in most cases there will be a simultaneous wobbling movement of the car body, i.e. a rotational movement will be incurred about a longitudinal axis of the car body pointing approximately in the direction of travel. Formulated in general terms, the car body has more than one degree of freedom for movements transversal to its longitudinal axis. If only the acceleration in a transversal direction is detected, acceleration movements which are felt as disturbing in transversal directions other than the transversal direction detected cannot be compensated for.

Added to this is the fact that, due to the resetting of the car body into a middle position relative to the undercarriage, additional wobble movements, in particular oscillations, can be incurred. This applies in particular for the usual situation in which an actuator for adjusting the transversal position of the car body is arranged beneath the car body floor, and therefore far beneath the car body centre of gravity.

With known systems which measure the transversal acceleration in one transversal direction only, it was not possible for active engagement to be effected in such frequency ranges which are appreciated as particularly disturbing, because the wobbling movements referred to earlier can precisely then be excited in resonance. If no information is available with regard to the wobble movement, the only possibility which remains is not to intervene at all in the critical frequency ranges. The range of frequencies in which it was hitherto possible to make an active intervention lay perceptibly below 1 Hz.

It is possible that other oscillations may occur as well as wobble movement oscillations, in particular in an approximately horizontal direction, and/or turning movement oscillations, i.e. about a height axis of the car body. It is known that oscillations in a specific frequency range, mostly about 3 Hz, will be sensed by persons in the car body as particularly disturbing, while by contrast oscillations with greater and/or smaller frequencies will not be felt as equally disturbing. A further finding of the invention is that it is felt as particularly disturbing if oscillations occur in different directions and/or rotational oscillations about different axes, and if these oscillations exhibit different frequencies. It is possible, on the basis of the invention, for oscillations with such disturbing frequencies and/or frequency combinations to be damped and/or to be avoided.

The invention enables greater travel comfort to be achieved, in that the transversal acceleration is determined in at least two different directions transversal to the car body longitudinal axis. For example, the transversal acceleration is determined in a first transversal direction, which, if the vehicle is travelling in undisturbed straight travel, lie in the horizontal plane, and the transversal acceleration is additionally determined in a second transversal direction approximately perpendicular to the first. Transversal acceleration sensors which can be used for this are known. In particular, the absolute transversal acceleration is determined. The term “absolute” is understood to mean that the transversal acceleration is determined in relation to an inertial system. It is not mandatory that all the components of the acceleration to be determined.

In particular, the incitement of a wobble movement can be directly determined. In addition, the substantially more precise knowledge of the movement state of the car body allows for a leading calculation, i.e. a calculation which can be extrapolated into the future.

In a preferred embodiment of the method according to the invention, in addition to this, with a determination of a manipulated variable for the adjustment of the relative transversal position of the car body, at least one characteristic of the movement behaviour of the car body is taken into account, in particular a characteristic for the excitation of oscillations of the car body, and/or due to the repeated evaluation of measured values and by temporal extrapolation of the movement behaviour of the car body, a possible future movement state of the car body can be calculated and taken into account when determining the manipulated variable. The taking into consideration of information relating to the movement behaviour of the car body does indeed require as a precondition the single acquisition and input of the minimum of one characteristic value (e.g. a static or dynamic value) for the movement behaviour, but also makes a high degree of travel comfort possible. The term “characteristic” is also understood to mean a parameter for a control algorithm, by means of which the movement behaviour is taken into account, and in particular the coupling of different oscillation movements. With regard to the initiation of a wobble movement, tests and simulations have shown that it is sufficient to use one or more actuators, which allow for an adjustment of the relative transversal position of the car body in one transversal direction only, such as the horizontal direction, for example, in undisturbed straight-ahead travel. A regulating system according to the invention can avoid the excitation of an oscillation movement about the longitudinal axis of the car body, e.g. by way of corresponding repeated adjustment of the transversal position in an approximately horizontal direction. In particular, changes in the transversal position in respect of the frequency and/or amplitude will be avoided, which would excite a resonance oscillation of the car body.

In one embodiment of the method, frequency ranges are considered in relation to the relative transversal position of the car body, and influenced by frequencies less than or equal to 10 Hz, in particular less than or equal to 7 Hz. This accordingly avoids even higher frequency ranges, in which the risk pertains that a peaceful run behaviour of the chassis will be impaired. In addition to this, in this way energy is also saved in relation to a higher-frequency regulating arrangement.

For preference, frequency ranges are considered in relation to the transversal position of the car body and influenced with a frequency less than or equal to 4 Hz, in particular less than or equal to 2 Hz, and the transversal acceleration of the car body is evaluated in a frequency range with a higher frequency and taken into account in the adjustment of the relative transversal position. This makes it possible for a rapid reaction to be achieved in comparison with previously-known solutions in response to deflections of the car body in the transversal direction, in particular due to entering a curve. Nevertheless, by the consideration of the transversal acceleration in a higher frequency range, high oscillation amplitudes in this higher frequency range can be avoided. In particular, this frequency range is a range in which oscillations, e.g. in accordance with an ISO Standard, are classified as particularly disturbing or undesirable. The separation of the frequency ranges for the consideration or evaluation of the transversal position and the transversal acceleration makes it possible for a stable regulation to be achieved both with regard to the avoidance/damping of oscillations as well as with regard to the regulating of the transversal position.

In one embodiment, the transversal acceleration of the car body is determined for at least two different positions and/or areas in the longitudinal direction of the car body, and, depending on this, the relative transversal position of the car body is adjusted at two different positions in the longitudinal direction of the car body. This makes possible in particular the regulating of a turning movement (yawing movement) of the car body about a height axis (e.g. an axis running in the vertical direction). To do this, it is possible for a turning acceleration of the car body about the height axis to be calculated from the determined values of the transversal accelerations of the car body at the minimum of two different places, and for this to be taken into account during the adjustment of the relative transversal position(s) of the car body. This enables travel comfort to be increased still further.

It is particularly preferred for the second and/or at least one higher temporal derivation of the transversal acceleration of the car body to be formed, and for the transversal position of the car body to be adjusted as a function of this. The transversal acceleration of the car body itself, and its first derivation, are less well-suited for the adjustment of the transversal position, because both a temporal constant transversal acceleration as well as a temporal constant first derivation in travelling around curves can be formed on the basis of the track keeping or track guiding. It is nevertheless also possible, in particular outside travel around curves, for the transversal acceleration and/or its first derivation to be used.

Accordingly, it is preferred, for a regulation of the yaw movement of the car body, for the first derivation and/or at least one higher temporal derivation of a turning acceleration of the car body, from the values of the transversal accelerations of the car body determined at least at two different places and/or areas in the longitudinal direction of the car body, to be calculated about a height axis and, depending on this, for the relative transversal position to be adjusted at two different positions in the longitudinal direction of the car body.

Depending on the manipulated variable which is calculated for the adjustment of the transversal position(s) of the car body, it may be favourable, for reasons of regulating technology, for a still higher stage of derivation to be used. For example, the manipulated variable could be a volume flow of a hydraulic valve, which controls the flow of a hydraulic fluid into and/or out of a hydraulic device. In this case, a constant volume flow corresponds to a sustained change in the relative transversal position. The control device accordingly exhibits an integrated behaviour, which to the purpose should be jointly taken into account during the regulating.

In particular, the transversal position of the car body can have a middle position, relative to the minimum of one undercarriage, for the straight-ahead travel of the vehicle. It is not mandatory for the car body to be reset into the middle position when travelling around curves. The regulating arrangement can detect, for example, that a complete reset is not favourable for travelling comfort. It may even be desirable for a complete reset to be avoided, in order to save energy for the adjustment work.

As a result of a regulating arrangement which reacts swiftly and/or dampens and/or prevents oscillations, the transversal spring attenuation can be designed quite generally as softer, because the risk of an impact against end stop elements, which delimit the possible transversal travel path, is reduced. The vertical spring attenuation between car body and undercarriage in many cases also fulfils the function of transversal spring attenuation. Air springs between the car body and the undercarriage are particularly comfortable, but contribute to the transversal attenuation with reduced spring force. One advantage of such a regulating arrangement therefore lies in the fact that soft air springs can also be used for a vertical spring attenuation between the car body and the undercarriage. Conversely, the regulating system needs to react less frequently and/or less strongly in response to interferences or impacts which are incurred.

An actuator for the adjustment of the relative transversal position between the car body and the undercarriage exhibits, for example, a hydro-pneumatic device with a container, which exhibits a diaphragm separating a chamber containing a gas and a chamber containing a fluid, and with a choke which chokes a volume flow into and/or out of the chamber containing the fluid from and/or to a storage vessel. Such an actuator can be drawn on to provide spring attenuation of impacts in the transversal direction which are initiated via the undercarriage.

In some cases, it is desirable to use not only one actuator to adjust a relative transversal position of the car body. For example, due to technical design reasons in some cases the actuator can only be arranged in such a way that, when it is actuated, a torque moment takes effect between the car body and the undercarriage. It is therefore proposed that a device for the adjustment of the relative transversal position should exhibit a first actuator and a second actuator, whereby the actuators are aligned and arranged in such a way that they can change the transversal position of the car body in a common transversal direction, whereby the actuators can in each case be actuated to take effect against each other by the application of a working pressure, and whereby the device exhibits means for the adjustment and/or delimitation of the sum total of the working pressures.

In addition to the measurement described above of the absolute transversal acceleration(s), it is proposed that the position of the car body relative to the undercarriage or undercarriages also be measured. In particular, the device for adjusting the relative transversal position can exhibit a position measuring device for the measurement of a position of the car body relative to the minimum of one undercarriage, whereby the position measurement device exhibits means for the measurement of the relative position in relation to two degrees of freedom for movements transversal to the car body longitudinal axis.

In particular, the position measuring device can exhibit a first transversal position sensor for the measurement of the relative transversal position of the car body, which measures the transversal position in a first transversal direction transversal to the longitudinal axis of the car body, and the position measuring device can exhibit a second transversal position sensor for measuring the relative transversal position of the car body, which measures the transversal position in a second transversal direction transversal to the longitudinal axis of the car body and transversal to the first transversal direction.

In addition to this, the device can exhibit at least two of the position measuring devices for the measurement of the relative position at different positions or in different areas in the longitudinal direction of the car body.

It is also proposed, by the combination of fast-working hardware and intelligent software, that the transversal accelerations and turning accelerations occurring on the car body be reduced independently of one another, whereby common actuators can be used for the adjustment of the transversal position(s).

A special expression of this invention is a regulating arrangement which is adapted to the hardware structure, which takes account of the link between wobble and transversal movement and in this way allows for the regulation of the transversal movement in respect of the minimisation of the car body transversal acceleration and the transversal deflection of the car body at its centre of gravity, as well as attaining a stabilization of the wobble movement. Without consideration of the linking of transversal and wobble movement, which results in particular from the design factor that the transversal actuators used do not take effect in the direction of the centre of gravity of the car body, a regulating arrangement of higher frequency in the sense of transversal travel comfort, and in this case in particular in the meaning of ISO Guideline 2631, necessarily leads to a build-up of the wobble movement in such a way that stable regulation becomes impossible.

One advantage of the regulating structure proposed hereinafter is that not only can the car body be centred in the transversal direction, and the car body transversal acceleration minimised, but also a wobble movement of the car body can be stabilized. In addition to this, a turning movement of the car body can be influenced. To summarise, by way of example the following properties or aims can be enumerated:

    • Low-frequency regulation of the transversal deflection of the car body;
    • In comparison with that, higher-frequency regulation of the car body transversal acceleration;
    • Stabilization of the wobble movement of the car body;
    • Low-frequency regulation of the turning movement of the car body about a height axis;
    • In comparison with that, higher-frequency regulation of the turning acceleration on the car body.

To provide further explanation of the invention, reference is made hereinafter by way of example to the appended drawings. The individual Figures of the drawings show, in a diagrammatic representation:

FIG. 1 A front view of a car body located in a spring-suspension manner on an undercarriage,

FIG. 2 The car body according to FIG. 1, after the induction of a transversal disturbance,

FIG. 3 The representation according to FIG. 2, whereby parts have been omitted for the sake of easier overview,

FIG. 4 A plan view of a car with two undercarriages and in each case two antagonistically-arranged transversal actuators.

FIG. 5 A function view of the arrangement according to FIG. 4,

FIG. 6 A function view of a hydro-pneumatic actuator between an undercarriage and the car body,

FIG. 7 A circuit arrangement in general principle of a regulating arrangement for the adjustment of the transversal position of a car body.

In the drawings the same reference figures designate parts which are the same and functionally the same.

FIG. 1 shows a rail vehicle with a car body 1 and an undercarriage 5. The undercarriage 5 exhibits two wheels 6. The undercarriage 5 is connected to the car body 1 by means of a right-side and a left-side secondary spring element 4, e.g. air springs, for the attenuation and damping of shocks primarily in the vertical direction. Air springs have transversal spring rigidity, even if small, in the transversal direction, which ensures the emergency running property of the system. Located on the undercarriage 5 is a securing element 67 extending upwards. Located on the car body 1 is a securing element 65 extending downwards. Arranged between the securing elements 65, 67 is an actuator 7, by means of which the relative transversal position of the securing elements 65, 67, and therefore of the car body 1 and the undercarriage 5 can be adjusted.

FIGS. 5a and 5b show diagrammatically, in the form of a circuit diagram, components of a mechanical model of the connection of the car body 1 to the undercarriage 5 and the undercarriage 5 on a track 9. The connection between the undercarriage 5 and the track 9 is not considered in any further detail. Connected in series with the actual actuator 7 is a spring element 7′, which corresponds to a rigidity of the secondary spring element 4 in the transversal direction. The reference numbers 8 and 15 designate damping elements for the damping of impacts between the car body 1 and the undercarriage 5. The actuator 7 and the spring element 7′ are, according to FIG. 5a, secured at one end to the car body 1 and at their other end to the undercarriage 5; they can, however, also take effect in mechanical series connection between the undercarriage 5 and the car body 1. To achieve symmetry of the effective actuator forces, according to FIG. 4 two actuators 7 are mirror-symmetrically arranged per undercarriage 5, lying transversal to the car body longitudinal axis, in order to achieve moment-free conduct of force at the securing element 65 oriented in the vertical direction.

FIGS. 2 and 3 show that a transversal interference incurred from the track 9 which is being travelled over, via the undercarriage 5, takes effect also as an actively-engendered actuator movement not only as a transversal displacement of the car body 1 but also as a wobble movement and possibly also as a turning movement of the car body 1. For the sensory acquisition of the state of the car body 1 deriving from this, and the acquisition of its centre of gravity (or of a point 2 on a longitudinal axis through the centre of gravity), not only transversal position sensors and high position sensors are used (not represented in the figure) but also transversal acceleration sensors 30. The transversal position sensors can be located at or in an actuator 7, and detect the transversal position of the car body 1 in the area of its floor, relative to the undercarriage 5 associated with it. One transversal position sensor on each undercarriage unit 5 is sufficient. One pair of high position sensors in each case are arranged for preference in the area of both ends of the car body, or in each case at one end of the car body on the right and left on the two car body longitudinal side walls, and in each case, on the right and left seen in the direction of travel, detect the vertical distance between the car body 1 and the undercarriage unit 5 allocated to it in each case. The high position sensors can also be integrated into the secondary spring elements 4, or interact with them.

The two transversal acceleration sensors 30 are arranged in the area of the longitudinal-side car body ends and detect the transversal acceleration values of the car body 1 as it enters into travel operation.

In the transversal direction, the actuators 7, which can actively adjust the relative transversal position and can be actuated by a computer 20, hold the car body 1. These actuators 7, as shown in FIGS. 5a and 5b, in each case have a springing and shock-absorbing property, and so connect the car body 1 to the individual undercarriage 5 in each case. In this way, transversal interferences from the rails are transferred gently into the car body. To increase travel comfort, the actuators 7 then create adjustment forces for the adjustment of the transversal position, which is specified by the regulating software.

The actuators 7 are in particular hydro-pneumatic actuators, as shown in FIG. 6 by the example of a single actuator 7. The actuator 7 exhibits a container 51, with a diaphragm 57 arranged in it. The diaphragm 57 subdivides the container 51 into a gas chamber 53, which contains a gas, and a fluid chamber 55, which contains hydraulic fluid. The fluid chamber 55 is connected via a choke 63 to a pressure chamber 61 and a fluid connection 60. Hydraulic fluid is conducted in a controlled manner via the fluid connection 60, through a valve, not shown, into the actuator 7, or conducted away from it. The choke 63 represents a fluid resistance, so that the actuator 7 has a shock-absorbing effect. Corresponding to the fluid pressure in the pressure chamber 61, the relative transversal position between the car body 1 and the undercarriage 5 is adjusted via a piston 59 and a piston rod 58, which engages at the securing element 67.

As is shown in FIG. 4, arranged at each undercarriage 5 are two actuators 7 of the same kind, taking antagonistic effect on each other. With the same pressure in each case in the pressure chamber 61 of the two actuators 7, the forces on the piston 59 are compensated for. The relative transversal position is therefore changed due to the introduction of a pressure difference. In order to prevent damage to or destruction of the actuators 7, the sum total of the pressures in the two pressure chambers 61 of the two actuators 7 of the same undercarriage 5 is limited to a maximum value.

In an alternative embodiment, however, provision is made for only one actuator 7 or a plurality of actuators 7, not taking effect against one another per undercarriage.

Hereinafter only one example is described for a sensor arrangement. The intention is to determine:

    • The inertial, i.e. absolute car body transversal acceleration and turn acceleration at the centre of gravity, and
    • The relative transversal displacement of the car body at the two bogies, as well as its relative turn and wobble angle.

Because a direct measurement of the transversal displacement of the car body centre of gravity is not practicable, several measured values are drawn on (see FIG. 2 and FIG. 3).

In the first step, the relative wobble angle (p, of the car body in relation to the front (v) and rear (h) undercarriage is calculated from the relative transversal deflections Yrv and Yrh of the actuators, in which a path sensor is located in each case: ψr=γr_v-γr_hlv+lh

    • lv and lh are the distance intervals between the actuators in the longitudinal direction of the centre of gravity.

By analogy with this, the turning acceleration

    • {umlaut over (ψ)}
    • can be determined with the aid of two transversal acceleration sensors on the car body. With two points, in each case the second temporal derivation of values is designated as: ψ¨=γ¨v-γ¨hlv+lh

In the next step, the relative wobble angle w is determined from the measured values of the vertical relative position Zr is determined at the secondary spring elements, taking into consideration the transversal distance interval lqv between the path sensors. The indices vr and vl mean “front right” and “front left”. w=zr_vr-zr_vllq_v

The measurement can be checked by adding vertical path sensors at the rear bogie.

Next, the relative transversal position Yr of the car body is calculated from the relative deflections of the actuators and the two relative wobble and turning angles determined heretofore (FIG. 7). γr=yr_v+γr_h2-z w-ψrlv-lh2

    • Z is in this situation the arithmetical mean value of the vertical relative positions right and left.

The car body transversal acceleration can be determined by analogous considerations. Two transversal acceleration sensors secured to the car body provide the car body transversal acceleration at the centre of gravity, when the portions resulting from the wobble angle and the wobble acceleration and turn acceleration of the car body have been adjusted.

Next, the absolute wobble acceleration is determined by means of vertical acceleration sensors secured to the car body. Vertical acceleration sensors at the rear part of the car body can support the measurement.

Account is further taken of the fact that the acceleration due to gravity provides an element to the measured transversal accelerations on the car body, above the absolute wobble angle of the car body, which means that, by applying an approximation of the absolute wobble angle, the car body transversal acceleration can be determined by way of a relative wobble angle filtered through a low-pass filter.

In addition to this, a pressure sensor is provided per actuator, in order to regulate the two antagonistic actuators of the each undercarriage with regard to the sum total of the pressures in the actuators.

With the sensor arrangement described, a transversal position regulation of the car body can be carried out. The aim of this regulation is to carry out the transversal position regulation in such a way that no build-up of the wobble movement takes place.

By way of example, the function of a regulation of the transversal position is shown in FIG. 7.

Because a constant transversal acceleration should not be used, but also not the almost constant first derivation of the transversal acceleration arising on curves, the transversal acceleration regulation must therefore use signals which contain the second and/or at least a higher temporal derivation of the transversal acceleration of the car body centre of gravity, or from which these can be derived.

An advanced calculation for the stabilization of the wobble movement takes place for preference by the use of at least two different derivations of the transversal acceleration of the car body centre of gravity. The determination of these derivation signals is effected in particular by means of a regulating technology filter with an order which is greater than the order of the maximum derivation stage used. The order of filtering is determined inter alia from the excitability of the car body in response to oscillations, and depends on how close the frequency range taken into account by the regulating arrangement lies to frequency ranges in which oscillations can be excited. The closer the range taken into account lies to the excitation range, and the easier oscillations are excited, the higher the order of filtering should be.

By analogy with this, the regulation of the turn acceleration can be carried out separately. For preference, the turn acceleration regulation does not make use of the turn acceleration itself, if an actuator with integrating effect is being actuated directly. It is therefore proposed that the first derivation of the absolute turn acceleration of the car body centre of gravity be used for the regulation.

In some cases in practice, no advance characteristics analogous to the transversal acceleration regulation are necessary with regard to the turning movement, and therefore additional higher temporal derivations of the turn acceleration do not necessarily have to be taken into account. With rail vehicles this is due, for example, to the fact that, due to the regulation, the risk does not arise of the excitation of oscillations of the car body. A filter of a smaller order is therefore adequate. Higher derivation stages can be used optionally, however, which in turn correspond to filters with higher orders.

Position regulation procedures regarding the transversal deflection of the centre of gravity of the car body and the turning angle of the car body with regard to the bogie can make use of an integrating effect of an actuator and therefore use only a P (proportional) portion and a D (differential) portion, which is likewise realised via a deep-pass filter of at least the second order. An integral portion can likewise be used, but for preference this has only a portion of regulator output signals typically smaller than one tenth.

Taking into account the geometric circumstances, the regulator output signals calculated in this way are distributed onto actuators arranged on the car body in the longitudinal direction almost at the end face. With hydraulically actuatable actuators, for example, volume flows of a hydraulic fluid for at least one actuator at the front (Qv) and one actuator at the rear (Qh) on the car body are calculated and adjusted, which, depending on the sign, are supposed to flow in or out, seen from the actuator. If two actuators are antagonistically arranged, the adjustment signal determined will be distributed with different signs to the right and left actuators.

It may be required that the relative car body transversal position should not be kept constant, but that the actuators should stay in their middle setting even when travelling around curves. In this way, the entire actuator path is always available in order to be able to compensate for dynamic transversal interferences. In this case, a reference signal for the car body transversal position is calculated in such a way that this is guaranteed. Determinant in this is the wobble angle of the car body derived as stationary from the curve travel. This can be calculated by back-calculation.

This reference signal, as described on the basis of FIG. 7, is low-frequency filtered and does not tale effect on a branch of the regulating process which processes derivations of the transversal acceleration. In this way, the reference signal is processed at low frequency without negative effect on the acceleration regulation.

A sum total pressure regulation of antagonistic actuators (as described heretofore) can be added to the regulating structure represented in FIG. 7. In this situation, the sum total pressure which is determined from the two antagonistic actuators in each case is used for the regulation. If the sum total pressure exceeds or falls short of a reference value, then, for example, the oil volume flow required for both actuators will be reduced or increased in the same direction by a fraction which is proportional to the deviation. The delimiting of the sum total pressure upwards prevents the risk of destruction of the actuators. Delimitation downwards guarantees stable regulation, which is not destabilized by changing the properties of the actuators, in particular the damping properties.

In particular, the reference transversal position of the car body centre of gravity 2 is determined as a filtered product from the wobble angle w and the distance interval h between the centre of gravity 2 and the engagement point of the actuator 7 on the securing point 65 (FIG. 3).

On the left in the upper block 70 in FIG. 7, the regulating branch begins for the generation of a reference value Yrs for a relative position of the car body centre of gravity in the transversal direction. To do this, the wobble angle w is used as an input variable; for example, during travel round a curve, the actuator should adopt or retain a middle position so that the full actuator path is available on both sides of the middle position.

Signals derived from this are processed to form volume flow control signals Qv for the hydraulic actuator 7 of the front undercarriage 5 and Qh for the hydraulic actuator 7 of the rear undercarriage 5, whereby these control signals control hydraulic valves which are connected in supply lines between one or more storage containers containing hydraulic fluid and the individual actuators 7.

As a further input variable, the car body transversal acceleration is conducted to an electric filter 81. The filter 81 delivers very small portions of the regulating output signals, both for high-frequency as well as low-frequency parts of the transversal acceleration oscillations measured or derived, for preference very much smaller than 10%. As a result of this, the oscillations are damped and/or prevented which are located in the middle frequency range located in between (typically 3-5 Hz) and which are perceived as being particularly interfering or are defined or normed as such. In addition, in this way energy can be saved for the adjustment of the actuators, since a regulating procedure operating in a narrower frequency range requires less energy, and, on the other hand, a more efficient regulator intervention is guaranteed in the frequency range in which the strongest negative effect on comfort is to be anticipated.

The regulating branch beginning in the left part of the block 70 exhibits a multiplier designated with the reference number 71, which multiplies the input signal for wobble angle w by the value h. h is the distance interval represented in FIG. 3 between the actuator and the car body centre of gravity 2. The output signal from the multiplier 71 is passed to a regulating element 73, which is adjustable. It can be adjusted in such a way that the regulating branch has no effect whatever, i.e. in particular when travelling around curves, no resetting takes place of a change incurred by centrifugal forces of the relative position between car body and undercarriage. It can also be adjusted in such a way, however, that such resetting is possible, or that the regulating branch is active. An output signal from the regulating element 71 is conducted to a low-pass filter 75. The low-pass filter 75 has the function of essentially making only the slow, i.e. low-frequency, portions of the wobble movements of the car body usable for the regulation procedure. For example, a disconnection edge of the low-pass filter 75 can be set to a value of between 0.1 and 0.5 Hz. Available at the output of the low-pass filter 75 is the reference signal Yrs for the relative position of the car body. The reference signal Yrs is compared with the measured value Yx in a differentiator element 89.

The differential signal is conducted to two electric filters 77 and 79, whereby the filter 77 delivers low-frequency signals which are proportional to the deviation between the reference value of the relative position of the car body centre of gravity and also proportional to the first temporal derivation of the differential signal. The filter 77 operates on a higher frequency than the low-pass filter 75. As far as possible it has no integrating effect. The filter 77, together with the filter 79, guarantees the transversal position regulation of the car body. The filter 77 does not deliver higher-frequency signals, in particular with a frequency greater than 2 Hz, which therefore guarantees a stable and reliable transversal position regulation.

The filter 79 has an integrating effect. The filter 79, like the filter 77, contributes to the transversal position regulation of the car body. The portion of the filter 79 is very small in comparison with filter 77, however, and for preference constitutes less than a tenth of the portion of the filter 77 in the regulator output signal. The portion of the filter 79 is suitable for eliminating an offset in the actuation of hydraulic valves. The filter is also effective at lower frequency than the filter 77. The output signals of the filters 77, 79, 81 are conducted to a summing element 91, and so produce a sum signal, which in turn is conducted to a summing element 93 and a differential forming element 95.

As is shown in the framed block 72 in FIG. 7 with the shaded lower part, a turn acceleration signal is conducted to a further filter 83, which delivers very small portions both for higher-frequency portions as well as for lower-frequency portions of the turn acceleration determined (for preference less than 10% of the regulator output signals). As a result of this, by analogy with the regulating described heretofore of the transversal position, in the block 70 oscillations are compensated for in a middle, particularly interfering range of, for example, 3-5 Hz. Attention is drawn to the advantages described heretofore. In addition to this, a signal corresponding to the turn angle which has been determined is conducted to an electrical filter 85, and, parallel to this, to a filter 87. Filter 85 delivers lower-frequency signals, which are proportional to the relative car body turn angle, and which are proportional to the first temporal derivation of the angle. The filter contributes to the regulation of the turn position of the car body. In the middle frequency range, in which the filter 83 is particularly effective (see above), or above this, no signals are delivered. Filter 87, like filter 85, contributes to the adjustment of the turn position of the car body. The portion of this filter in comparison with the filter 85 should be very small (e.g. less than 10%) and is suitable for eliminating an offset during the actuation of hydraulic valves. The filter 87 is also effective at lower frequencies than the filter 85.

Like the filters 77, 79, and 81, the filters 83, 85, 87 should not overlap in their effective frequency ranges, or as little as possible, i.e. in the frequency ranges in which they deliver effective portions for the regulator output signals.

The output signals from the filters 83, 85, and 87 are conducted to a summing element 97, which is in turn conducted to the summing element 93 and the differential forming element 95.

The summing element 93 issues the output signal Qv. The summing element 95 issues the output signal Qh.

As an option, an amplifier can be provided for between the summing elements 91, 97, and the summing element 93 or the differential forming element 95 respectively, in order to take account of the geometry and mass circumstances of the vehicle which is to be controlled.

Overall, therefore, the situation is achieved in that, with little effort in terms of measurement technology, the essential factors are detected for a pleasant travelling sensation, and a stable and jerk-free positioning of the car body in travel operation. In particular, vibrations arising on the car body can also be eliminated, and the excitation of a wobble movement of the car body, which under certain circumstances derives from this, can also be done away with. In addition to this, by taking account of the connection between the wobble movement and the transversal movement, a stabilization of the wobble movement can also be achieved.





 
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