Closed-loop control device for a railway vehicle braking system

Abstract

The present invention relates to a closed-loop control device (R) for a braking device (B) of a railway vehicle (S), adapted to closed-loop control of at least one parameter of only this braking device (B), the closed-loop control device (R) comprising at least one sensor device (3) adapted to measure at least one operating parameter of a wheel unit (W) associated with the braking device (B), the at least one operating parameter measured by the at least one sensor device (3) being an operating parameter of the wheel unit (W) associated with the braking device (B), as well as a target value (a Soll ) and receives the operating parameters and target values (a Soll ) to calculate the operation amount (G Stell ) and the manipulated variable (G Stell ) is supplied to the braking device (B). Soll ) may be greater or less than the operating parameters of the wheel unit (W) associated with the braking device (B).

Description

[Technical Field]

[0001] The present invention deals with closed-loop deceleration control for rail vehicles using local controllers.

[0002] When designing braking systems for railway vehicles, it is desirable to have as good a reproducibility of the braking process as possible - this allows the actually achieved train deceleration to be decoupled from variable operating conditions, such as the influence of weather, tolerances in the braking and bogie equipment, etc.

[0003] This allows for more stable braking characteristics and more consistent braking distances - it is no longer a question of shortening the braking distance, but of making the braking distance reproducible, i.e. always the same under the same basic conditions. When any braking is performed on a railway vehicle, the constant conditions in the braking system usually result in the same deceleration and therefore always a consistent braking distance, since the same braking force acts on each wheel.

[0004] However, such ideal conditions are not realistic in practice, since the resulting braking distance, even if the force coupling conditions are sufficient, is subject to large tolerances due to, for example, varying friction values of the brake lining-brake disc friction pair, brake disc temperature, brake caliper aging and other variables.

[0005] Closed-loop deceleration control of a train of several railcars is often performed centrally, with a central controller simultaneously controlling all railcars in the train. However, problems can arise when communication paths fail, and local closed-loop deceleration control may not be possible (e.g., in a braking unit that is disconnected due to a communication error).

[0006] Furthermore, long communication times exist between rail vehicles, which can adversely affect the closed-loop control. Furthermore, communication times may vary between individual braking units, which also degrades the quality of the closed-loop control.

[0007] The prior art is known, for example, from the publication EP 3681772 A1, which describes a motion control and emergency control system for at least one railway vehicle. This publication discloses a system that can increase the applied rotary brake torque if the current deceleration value is less than the target deceleration value. In other words, excessively low deceleration can be locally compensated for by increasing the braking force.

[0008] Furthermore, the publication EP 3056397 A1 discloses a braking control device in which a calculation unit distributes the total braking force required to achieve a specific deceleration to different railway vehicles or braking devices.

[0009] Furthermore, the prior art discloses the publication GB 2 402 983 A1, in which measured values, such as wheel speeds, are transferred to a data processor which allows individual closed-loop control of the brake pressure on each axle, on each bogie or on each railcar, where a central data processor is used as well as other sub-data processors which are able to evaluate the measured values of specific axles or bogies.

[0010] The prior art also includes the publication US 2004 / 0046442, which discloses a braking system for railway vehicles, in which each bogie is connected to a pressure line and the braking devices can be controlled by at least one local electronic braking control unit, whereby operating data is exchanged between the individual braking control units, which are also connected to a central braking control unit via a data bus.

[0011] Therefore, in the prior art, a central controller is often provided, which has the disadvantage that communication between the central controller and the individual braking devices can be disrupted.

[0012] The object of the present invention is to provide a closed-loop control system for railway vehicles, which allows for local, i.e. chassis-by-chassis, railway vehicle-by-carriage, wheel-by-wheel or axle-by-axle closed-loop control of braking forces, and nevertheless achieves a high closed-loop control quality.

[0013] This problem is solved by a closed-loop control device according to claim 1, a railway vehicle according to claim 9 and a train coupler according to claim 12.

[0014] Further advantageous embodiments of the invention are the subject of the dependent claims.

[0015] A closed-loop control device for a braking device of a rail vehicle according to the present invention is configured to perform closed-loop control of at least one parameter of the braking device. The braking device may be arranged on a wheel unit, a bogie, or a car. The wheel unit may include individual or multiple logically or technically coupled wheels (e.g., two wheels on an axle, wheels on a bogie). The closed-loop control device has at least one sensor device adapted to measure at least one operating parameter of the wheel unit associated with the braking device or of the bogie or car associated with the braking device. A controller is also provided, which is adapted to receive or determine, depending on an external signal (e.g., during emergency braking), at least the operating parameter measured by the at least one sensor device, one operating parameter of the wheel unit associated with the braking device, as well as a target value, and to determine, from the operating parameter and the target value, an actuating variable for the braking device, which is also supplied to the braking device. The setpoint value may be greater or less than the operating parameter of the wheel unit associated with the braking device - thus allowing a fully closed-loop control, in which the actuated variable may be the brake pressure, the braking force / braking effort (e.g. for electromechanical brakes) or the current (e.g. for eddy-current brakes). However, the actuated variable may also be a correction factor acting on a nominal actuated variable, e.g. pressure, etc. The reference value here is a setpoint deceleration that the closed-loop control device receives from the outside (e.g. from a calculation unit which calculates the setpoint value for the braking force of the respective brake) or it may be stored in the closed-loop control device itself and triggered via an external signal (e.g. an emergency braking signal).

[0016] Such local closed control loops can operate independently of each other and can also have dynamic characteristics related only to the corresponding brake device, and such a local system only accesses local sensors, i.e. sensors associated with the wheel units braked by the brake device.

[0017] Furthermore, costs can be reduced in railcars by eliminating the need for a central master controller, and wiring costs are reduced.

[0018] Regardless of the communication architecture and the resulting error modes (or even in the event of a fault or failure), the braking force of each braking device can be influenced by closed-loop control to achieve the desired deceleration.

[0019] What is important is that the target pressure braking force can be increased or decreased - that is, not only is compensation provided, but correct closed-loop control is provided.

[0020] This arrangement allows for a closed control loop of the sensor system and the actuator system.

[0021] The parameter of the braking device that is closed-loop controlled by the closed-loop control device is preferably the deceleration, thereby realizing local closed-loop control of the deceleration, so that each braking device on the railway vehicle can have the same target deceleration, which is locally closed-loop controlled.

[0022] The at least one sensor device is preferably a deceleration sensor, a wheel rotation speed sensor and / or a GPS sensor, by means of which corresponding values important for determining the deceleration can be measured. Preferably, a calculation unit is further provided which is adapted to determine the actual deceleration from the values of the wheel rotation speed sensor and / or the GPS sensor - in this case, the deceleration sensor can be omitted and one or more other sensors can be used to determine the corresponding deceleration.

[0023] The actuating variable is preferably a brake pressure, a brake force / braking force, a brake torque or a current - a brake pressure may be used, for example, in pneumatic or hydraulic brakes, a brake force may be used, for example, in electromechanical brake actuators, and a current may be used, for example, in eddy current brakes.

[0024] The at least one sensor device is preferably adapted to measure at least one operating parameter of only the wheel unit associated with the braking device, and the corresponding controller is in this case adapted to receive the at least one operating parameter measured by the at least one sensor device, which is only the operating parameter of the wheel unit associated with the braking device.

[0025] This means that a closed control loop is provided which further enables fast closed loop control since only local sensor data is used by the controller, thus avoiding long communication paths.

[0026] In the closed-loop control, the deviation of the manipulated variable (brake pressure, brake force, brake torque or current) from a defined reference point is preferably taken into account. In this case, (when the brake pressure is controlled in a closed-loop as the manipulated variable) the control deviation of the deceleration not only affects the brake pressure or brake application force to be adjusted, but also the deviation from a reference pressure or force, e.g., a "standard pressure" or "reference force" calculated for a specific deceleration request. This helps to ensure that the manipulated variables cannot diverge from one another.

[0027] The closed-loop control device is preferably adapted so that the local driving resistance is taken into account in the closed-loop control of the manipulated variables.

[0028] In particular, if the target deceleration is derived locally from the emergency braking signal, this improves the deceleration characteristic.

[0029] As previously explained, the railway vehicle according to the present invention comprises at least one wheel unit, at least one braking device associated with the at least one wheel unit, and at least one closed-loop control device. Each closed-loop control device is associated with one braking device. Preferably, the at least one closed-loop control device is associated with only one braking device, i.e., not two braking devices on the bogie or otherwise.

[0030] Furthermore, at least one closed-loop control device can be configured redundantly, so that if a local closed-loop control device fails, it can be avoided that the wheel unit is not decelerated closed-loop controlled, since the redundant closed-loop control device can take over in the event of a failure of the closed-loop control device.

[0031] The train combination according to the present invention includes at least two rail cars and further a braking amount calculation unit adapted to calculate a target deceleration for each braking unit based on a signal of a braking demand input device.

[0032] However, a problem can arise here, in that the actuated variables (e.g. brake pressures) of several existing brake units can deviate from one another, which can lead to problems with force coupling, since different brake units can have braking forces that deviate from one another at the control limits, and some brake units can exceed the predefined force coupling limits in certain situations.

[0033] However, a braking request can be input by a user, e.g., a train driver, via a braking request input device. In this case, each closed-loop control device receives a corresponding, preferably identical, target deceleration to be closed-loop controlled accordingly. This makes it possible to avoid large deviations between the control variables.

[0034] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. [Brief explanation of the drawings]

[0035] [Figure 1] FIG. 1 shows an arrangement of three local closed-loop control devices associated with corresponding braking devices. [Figure 2] 1 is a diagram illustrating a closed control loop of a closed loop control device according to the present invention; [Figure 3] 1 shows a train coupler according to the invention with three rail cars or carriages; FIG.

[0036] Figure 1 shows three closed-loop control devices R, R', R'' schematically. Each of these closed-loop control devices consists of a controller 2, 2', 2'' and a sensor 3, 3', 3'' associated with a corresponding braking device B, B', B''.

[0037] Via a communication network 4, the controllers 2, 2', and 2" are connected to a braking quantity calculation unit 1, which is itself connected to a braking demand input device A. The braking demand input device A allows, for example, a train driver to input the desired deceleration of the entire train or a train combination. In response, the braking quantity calculation unit 1 calculates the distribution of braking forces for the individual braking units B, B', and B" and forwards this distribution to the corresponding controllers 2, 2', and 2". The communication network 4 is arranged in one direction by the arrows, i.e., only target values are pre-set by the braking quantity calculation unit 1 to the individual controllers 2, 2', and 2" - the controllers do not return any quantities to the braking quantity calculation unit 1, and these quantities are not used for centralized monitoring of the controllers 2, 2', and 2". However, in the event of emergency braking, the target values can also be generated locally by the controllers 2, 2', and 2'", - in this case the corresponding controllers only receive an emergency braking signal from the braking quantity calculation unit 1.

[0038] Each of the closed-loop control devices R, R' and R'' acts purely locally and in this example affects a brake B, B' or B''. It is also possible to affect the brakes of the bogie, i.e. both brakes, but it is usually better to have each brake controlled individually in a closed loop.

[0039] A closed control loop according to the present invention is shown schematically in Figure 2. The controller 2 controls the target deceleration a Soll and actual deceleration a Ist is set. From this, the manipulated variable G Stell , in this case the braking force is calculated which is transferred to the corresponding braking unit B. From here, feedback is provided, since at the corresponding wheel the corresponding deceleration value a Ist is measured - if the sensor 3 is, for example, an acceleration sensor, a wheel speed sensor or a GPS sensor, a calculation unit 5 is further provided, by which the corresponding deceleration is calculated therefrom. Here, feedback of the actual deceleration is provided, which is itself supplied to the controller 2.

[0040] Therefore, a closed control loop is provided, which prevents actual deceleration values a that are too large or too small. Ist It is possible to react accordingly, i.e. to control the manipulated variable in a closed loop upward or downward direction in order to adapt the desired deceleration to the actual deceleration.

[0041] FIG. 3 shows a train combination Z according to the invention, consisting of three railway cars S, S' and S". A braking quantity calculation device 1 is connected to a braking request input device A. The braking quantity calculation unit 1 is connected to respective local controllers 2, 2', 2" and 2'" which are respectively associated with braking devices B, B', B" and B'" - which are themselves associated with wheel units W, W', W' and W'" - respectively. Respective local sensors 3, 3', 3", 3'" are provided - the controllers 2, 2', 2" and 2'" only take in the local sensor values of the respective sensors 3, 3', 3", 3'". Via the communication network 4, only the braking quantities of the braking quantity calculation unit 1 are set in the respective controllers 2, 2', 2" and 2'" - there is no communication in the opposite direction.

[0042] The present invention is not limited to the above-mentioned embodiments.

[0043] For example, a multiple sensor may be provided which determines the actual deceleration from different measurements. [Explanation of symbols]

[0044] 1 Braking amount calculation unit 2,2',2'',2''' Controller 3,3',3'',3''' sensor device 4. Communication Network 5 Computational Units R Closed-loop control device S, S', S'' railcars B,B',B'' Braking device Z train connection W,W',W'',W''' Wheel unit G Stell Operation amount a Ist Actual Deceleration a Soll Target deceleration RF reference point

Claims

1. A closed-loop control device (R) for a braking device (B) of a railway vehicle (S), the closed-loop control device (R) being adapted to closed-loop control of at least one parameter of said braking device (B) only, comprising: at least one sensor device (3) adapted to measure at least one operating parameter of a wheel unit (W, W', W'', W''') associated with said braking device (B); At least one operating parameter measured by at least one sensor device (3), the operating parameter of the wheel unit (W, W', W'', W''') associated with the braking device (B), and a target value (a Ｓｏｌｌ ) or depending on an external signal, determine said operating parameters and said target values (a Ｓｏｌｌ ) to the braking device (B), Ｓｔｅｌｌ ) and the manipulated variable (G Ｓｔｅｌｌ a controller (2) adapted to supply the braking device (B) with The target value (a Ｓｏｌｌ ) may be greater or less than the operating parameters of the wheel units (W, W', W'', W''') associated with the braking device (B).

2. 2. The closed-loop control device (R) according to claim 1, wherein the parameter of the braking device (B) that is closed-loop controlled by the closed-loop control device (1) is deceleration.

3. 3. The closed-loop control device (R) according to claim 1 or 2, wherein the at least one sensor device (3) is a deceleration sensor, a wheel rotation speed sensor or a GPS sensor.

4. Furthermore, the actual deceleration (a Ｉｓｔ 4. The closed-loop control device (R) according to claim 3, comprising a calculation unit (5) adapted to determine:

5. The operation amount (G Ｓｔｅｌｌ 5. The closed-loop control device (R) according to claim 1, wherein the brake pressure, brake application force or current is selected from the group consisting of brake pressure, brake application force and brake current.

6. 6. The closed-loop control device (R) according to claim 1, wherein the at least one sensor device (3) is adapted to measure at least one operating parameter of only the wheel unit (W, W', W'', W''') associated with the braking device (B), and the controller (2) is adapted to receive the at least one operating parameter measured by the at least one sensor device (3), which is the operating parameter of only the wheel unit (W, W', W'', W''') associated with the braking device (B).

7. During the closed loop control, the manipulated variable (G Ｓｔｅｌｌ 7. The closed-loop control device (R) according to claim 1, wherein deviations of the control signal (R) are taken into account.

8. The operation amount (G Ｓｔｅｌｌ 8. The closed-loop control device (R) according to claim 1, wherein the local road resistance is taken into account in the closed-loop control of the vehicle.

9. A railway vehicle (S), at least one wheel unit (W, W', W'', W'''); at least one braking device (B) associated with at least one of said wheel units (W, W', W'', W'''); 9. A railway vehicle (S) comprising at least one closed-loop control device (R) according to claim 1, each associated with one braking device (B).

10. 10. The railway vehicle (S) according to claim 9, wherein at least one closed-loop control device (1) is associated with only one respective braking device (B).

11. 11. The railway vehicle (S) according to claim 9 or 10, wherein at least one closed-loop control device (1) is provided redundantly.

12. A train coupler (Z), 12. A system for controlling at least two railway vehicles (S) according to any one of claims 9 to 11, and a system for controlling target decelerations (a) for respective braking units (B, B', B'') based on a signal from a braking request input device (A). Ｓｏｌｌ , a Ｓｏｌｌ’ , a Ｓｏｌｌ’’ and a braking amount calculation unit (1) adapted to calculate Each closed-loop control device (R, R', R'') determines the corresponding target deceleration (a Ｓｏｌｌ , a Ｓｏｌｌ’ , a Ｓｏｌｌ’’ ) can be received by the train coupler (Z).

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