Time-controlled brake pressure switching for rail vehicles

Abstract

Device for controlling a braking system of a rail vehicle to prevent the applied braking force from no longer being absorbed via the frictional contact between wheel and rail, wherein the braking process is an emergency braking action and a change is an increase in brake pressure, comprising: - a time control device (12; 120) for determining at least one predicted time point (t0) or period (UB) t ) for a change in brake pressure based on speed data of the rail vehicle available when initiating a braking process, and - a brake pressure adjusting device (12; 122) for initiating the change in brake pressure when the predicted time or period is reached, - wherein the brake pressure adjusting device (12; 122) is configured to initiate the change in brake pressure by sending a modified load pressure signal (Tmod) to a brake control valve device (14), which in response to this sends a corresponding brake control pressure (Cn) to a pressure converter or a pressure booster for a pneumatic brake device, - wherein the brake pressure adjusting device (12) is designed such that it receives a speed signal (v) and a load pressure signal which indicates a load value (T) of the rail vehicle, characterized in that - based on the last available speed signal (v) and taking into account the load (T), a brake timing control device (120) determines a predicted time course of the variable load pressure signal (Tmod) based on an algorithm or a memory table and applies it to the brake control valve device (14) in order to achieve an optimized pressure switching for the initiated braking, - wherein the predicted time course of the load pressure signal (Tmod) is supplied as an electrical signal or in parameter form to a correspondingly controllable brake pressure adjusting device (122) which generates a correspondingly modulated load pressure signal (Tmod).

Description

[0001] The present invention relates to a device for controlling a braking system for rail vehicles. The invention also relates to a braking system for a rail vehicle.

[0002] Modern rail vehicles frequently use pneumatic braking systems controlled by electronic brake control units. In particular, an emergency braking system is designed to ensure that a minimum emergency braking control pressure is available to operate the brake actuators of the pneumatic braking system. However, during an emergency braking application, there is an increased risk that the braking force applied will be so harsh that the frictional contact between the wheel and the rail can no longer absorb it. This can lead to the wheels locking. Furthermore, an emergency braking application often results in jerky behavior of the rail vehicle, which can endanger standing passengers in particular.

[0003] JP 2003-259 502 A shows a device for controlling a braking device of a rail vehicle with a time control device for determining at least one predicted time or period for a change in a braking pressure based on speed data of the rail vehicle available when initiating a braking operation.

[0004] DE 10 2011 110 047 A1 discloses an emergency braking device for a rail vehicle, comprising an emergency braking control valve device for providing an emergency braking control pressure for a pneumatic braking device of the rail vehicle. The emergency braking device comprises an emergency braking pressure adjustment device for adjusting the emergency braking control pressure depending on a load value of the rail vehicle or a speed value of the rail vehicle. Thus, even during emergency braking, wheel locking can be avoided, and smooth braking can be achieved. Furthermore, a braking pressure adjustment device is disclosed, which is designed to initiate the change in the braking pressure.

[0005] DE 10 2016 100 290 A1 describes a device and a method for controlling a braking device, preferably an emergency braking device, of a rail vehicle. At least one switching parameter for a change in a braking pressure of the braking device generated by a pressure converter is detected, and a trigger signal is generated in response to a determined predetermined value of the switching parameter. A brake control pressure for the pressure converter is introduced into an air reservoir, and a supply of the brake control pressure from the air reservoir to the pressure converter is opened in response to the trigger signal.

[0006] Fig. Figure 1 shows a diagram with a schematic progression of the brake pressure (C) for a pneumatic braking system as a function of the speed (v) of the rail vehicle. Starting at a predetermined speed within a speed-dependent switching range UB vThe brake pressure (or "c-pressure") for emergency braking in conventional emergency braking systems is regulated speed-dependently, for example, in two stages (high / low) using a pressure intensifier (EDU). As shown in the diagram in Fig. As shown in Figure 1, the switching can also take place in several speed-dependent stages or be continuously controlled.

[0007] For speed-dependent switching, the train's speed must be transmitted reliably and at the right time. However, this involves considerable technical effort.

[0008] The present invention is therefore based on the object of providing a device and a method for controlling an emergency braking device for rail vehicles, by means of which the technical effort associated with preventing the locking of the wheels and enabling jerk-free braking can be reduced.

[0009] This object is achieved by the device according to claim 1.

[0010] Further advantageous embodiments and developments of the invention emerge from the dependent claims.

[0011] According to the invention, the change or switching of the brake pressure no longer needs to be speed-dependent. It can be controlled time-dependently based on a temporal forecast. The start of the change can be triggered, for example, by a time-dependent trigger. This allows for greater flexibility in the design of the switching and brake control and reduces the effort required to obtain the speed data, which can be subject to lower demands on its time accuracy and reliability.

[0012] Within the scope of this description, the device for controlling the emergency braking system can be implemented as software, hardware, or a combination of software and hardware. It can have one or more interfaces to exchange suitable data with other devices of the vehicle. The control device can be implemented as one or more modules and / or processes and / or objects and / or threads.

[0013] According to the invention, a device for controlling a braking device of a rail vehicle is provided, comprising a time control device for determining at least one predicted time or period for a change in a braking pressure based on speed data of the rail vehicle available when initiating a braking operation, and a brake pressure adjustment device for initiating the change in the braking pressure in response to reaching the predicted time or period.

[0014] According to the invention, a braking system for a rail vehicle is further provided, which has a device according to the invention.

[0015] Furthermore, according to the present disclosure, a method for controlling a braking device of a rail vehicle is provided, comprising the steps of determining at least one predicted time or period for a change in a brake pressure based on speed data of the rail vehicle available when initiating a braking operation, and initiating the change in the brake pressure in response to reaching the predicted time or period.

[0016] Furthermore, the present disclosure relates to a computer-readable storage medium on which a program code executable on a computer system is stored, which generates or implements the steps of the aforementioned method.

[0017] Furthermore, the present disclosure relates to a computer program with code means which, when executed on a computer system, generate or implement the steps of the aforementioned method.

[0018] According to the invention, the braking operation is an emergency braking operation, and the change is an increase in brake pressure. Preferably, the timing device can be configured to determine the predicted time or period based on a forecast of the deceleration curve of the rail vehicle after the initiation of the braking operation.

[0019] According to a preferred development of the invention, the time control device can be designed to generate a trigger signal for the change in the brake pressure upon reaching the predicted time or period, wherein the brake pressure adjustment device initiates the change in the brake pressure in response to detection of the trigger signal.

[0020] According to an alternative preferred development of the invention, the brake pressure adjustment device can be designed to initiate a sudden, step-like or ramp-like change in the brake pressure.

[0021] According to the invention, the brake pressure adjustment device is designed to transmit a modified load pressure signal to a brake control valve device in order to initiate the change in the brake pressure, which, in response thereto, transmits a corresponding brake control pressure to a pressure converter or a pressure booster for a pneumatic brake device.

[0022] The invention is explained in more detail below using exemplary embodiments with reference to the accompanying drawings. They show: Fig. 1 a diagram with alternative schematic curves of a speed-dependent braking force in a conventional emergency braking device; Fig. 2 is a schematic block diagram of an emergency braking device according to a first embodiment; Fig. 3 is a schematic block diagram of an emergency brake pressure adjustment device for the emergency brake device according to the first embodiment; Fig. 4 is a time diagram with alternative schematic curves of a time-dependent braking force in an emergency braking device according to the first embodiment; and Fig. 5 a flowchart of a control method according to a second embodiment.

[0023] The following is a description of advantageous embodiments based on an exemplary emergency braking device for a rail vehicle for providing an emergency braking control pressure for a pneumatic braking device of the rail vehicle.

[0024] Fig. 2 schematically shows an emergency braking device with an emergency braking pressure adjustment device (NBDE) 12 and an emergency braking control valve device (NBSVE) 14. The emergency braking control valve device 14 can be connected to a main air line (not shown). Furthermore, the emergency braking control valve device 14 is connected to a standard pressure converter (EDU) 16, which converts an applied control pressure, such as an emergency braking control pressure Cn, into a corresponding braking pressure C. Furthermore, a main braking control valve device (HSVE) 18 is shown, via which a control pressure Cv can be provided during normal operation, for example during normal service braking. The standard pressure converter 16 can convert the control pressure Cv into a corresponding braking pressure C. The main braking control valve device 18 can be controlled by an electronic braking control device (BSE) 10.

[0025] In the event of an emergency braking, the emergency braking device is actuated or otherwise activated, possibly bypassing the main control valve device 18. In one variant, the emergency braking control valve device 14 can be connected between the standard pressure converter 16 and the main control valve device 18. It should be noted that instead of the standard pressure converter 16, a pressure amplifier can also be used, which not only transfers an applied control pressure to a larger volume but also increases it.

[0026] The emergency brake control valve device 14 can be controlled, for example, by a pressure drop in a main air line of the rail vehicle to initiate an emergency braking operation. Accordingly, the emergency brake control valve device 14 provides the emergency brake control pressure Cn, which is forwarded to the standard pressure converter 16. This emergency brake control pressure Cn is modified by a pneumatic load control pressure provided by the emergency brake pressure adjustment device 12. For this purpose, a pneumatic load pressure signal Tmod is applied to the emergency brake control valve device 14. Using suitable pneumatic components, the emergency brake control valve device 14 adjusts the control pressure it outputs according to the modified load pressure signal Tmod.

[0027] The emergency brake pressure adjustment device 12 can, for example, be designed to receive a pneumatic load pressure signal indicating a load value T of the rail vehicle or an associated axle of the rail vehicle. This signal can originate, for example, from an air bellows. Furthermore, a speed signal v is supplied to the emergency brake pressure adjustment device 12. This signal can be an electrical or pneumatic signal. The emergency brake pressure adjustment device 12 is designed to determine a temporal profile of the variable load pressure signal Tmod based on a previous value of the speed signal and apply it to the emergency brake control valve device 14.For this purpose, the emergency brake pressure adjustment device 12 can also comprise an integrated or separately arranged electronic emergency brake control device (not shown), by means of which the setting of the emergency brake pressure is controlled by determining and generating the corresponding load pressure signal Tmod.

[0028] The time dependency of the load pressure signal Tmod is set, for example, depending on a last detected speed value, so that the pressure switchover during emergency braking is not speed-dependent but time-controlled. The start of the switchover can be triggered, for example, depending on a determined time control by a time-based trigger signal UTr (e.g., a predetermined pulse or signal value) generated by the emergency brake pressure setting device 12 (or its emergency brake control device) or by an external device after the emergency braking has been initiated. Such a time-dependent controlled switchover of the emergency brake pressure allows for greater flexibility in the design of the switchover and the emergency brake control.

[0029] The time-dependent control of the load pressure signal Tmod can be pneumatically or electropneumatically controlled. For example, the emergency brake pressure adjustment device 12 can have a pressure rocker that pneumatically generates a correspondingly modified load pressure signal Tmod. The time-dependent control can be configured such that at times corresponding to a brake-dependently estimated high speed (i.e., when experience shows that the adhesion coefficient between wheel and rail is lower than at a lower speed), the time-modified value of the load pressure signal Tmod is set lower than at times corresponding to a brake-dependently estimated lower speed.

[0030] Thus, the emergency brake control valve device 14 is provided with a “virtual” load pressure signal Tmod with a time curve calculated in advance based on a last detected speed value.

[0031] Fig. Figure 3 shows an exemplary schematic block diagram of the emergency brake pressure adjustment device 12 for the emergency brake system according to the first exemplary embodiment. Based on a previous value of the speed signal v and taking into account the load T of the rail vehicle, an emergency brake time control device (NBZS) 120 determines a predicted time profile of the load pressure signal Tmod for optimized pressure switching for the initiated emergency braking. The predicted time profile and / or the trigger signal UTr are then fed as an electrical signal or in parameter form to a correspondingly controllable emergency brake pressure adjustment device 122, which, in response, generates a correspondingly modulated load pressure signal Tmod.

[0032] Fig. 4 shows a time diagram with alternative schematic curves of a time-dependent braking force switching in an emergency braking device according to the first embodiment.

[0033] When the emergency brake is triggered, for example, the last available speed signal is evaluated. Based on the corresponding speed data of the available speed signal, a predetermined time t0 and / or a temporal switching range (switching window) UB can be determined using a deceleration behavior of the rail vehicle predicted, for example, based on an algorithm or a memory table. t can be determined in which the rail vehicle has reached the correct or optimal speed for switching. Within the switching window UB t or at the predetermined time t0 the brake pressure is increased during the emergency braking process.

[0034] As in Fig. 4, the increase in the brake pressure C depending on the generated load pressure signal Tmod can alternatively be carried out in a jump-like manner at the predetermined time t0 or in a step-like or ramp-like manner (continuously) within the time switching window UB t be controlled.

[0035] Accordingly, at times with high predicted speed, a lower brake control pressure Cn and thus also a lower brake pressure C is provided for emergency braking.

[0036] Fig. 5 shows a flowchart of a control method for an emergency braking device according to a second embodiment, which can be implemented, for example, in an emergency braking control device as software for computer control.

[0037] The program start is initiated, for example, when an emergency brake is triggered. In step 501, the speed data of an available speed signal v is evaluated, if necessary with the help of available load data T, in order to predict the deceleration behavior of the rail vehicle in question, for example using a memory table or an algorithm. Based on the predicted deceleration behavior, in step 502 at least one switchover time for a sudden, stepped or ramp-like change in the emergency brake pressure is determined, for example using a memory table or an algorithm. Alternatively, a switchover window can also be determined within which the switchover is to take place. Then, in step 503, a comparison with a timer checks whether the determined time or the determined switchover window has been reached or not. If not, step 503 is repeated until the determined time orthe determined switching window has been reached. As soon as it is determined in step 503 that the determined time or the determined switching window has been reached, the process proceeds to step 504, and the brake pressure for the emergency braking is increased abruptly, step-wise, or ramp-wise according to a desired temporal transition function. The determination of reaching the determined time or the beginning of the determined switching window can also be signaled by generating and emitting the trigger signal UTr, so that step 504 is initiated in response to detection of the trigger signal UTr.

[0038] The control for increasing the brake pressure during emergency braking can be implemented by a program-controlled computer device provided in the emergency braking device, in which the steps of Fig. 5 be controlled by means of a computer program which is stored, for example, on a computer-readable storage medium or which is downloadable via a network such as the Internet or a local area network.

[0039] In the embodiments described above, the brake control device 10 can be Fig. 2 may also include an electronic wheel slide protection control device or a wheel slide protection computer. The wheel slide protection computer can be connected to one or more relief valves to provide a wheel slide protection function. For this purpose, the relief valves are arranged in the compressed air circuit downstream of the standard pressure converter 16, which provides the brake pressure for pneumatic actuators (not shown). The relief valves can reduce the brake pressure applied to specific actuators according to the wheel slide protection computer.

[0040] The wheel slide protection computer can, for example, determine the vehicle speed v from data from wheel speed sensors. Speed ​​data can then be transmitted from the wheel slide protection computer to the emergency brake pressure adjustment device 12, which receives this information and evaluates it to predict the time course of the load pressure signal Tmod. The emergency brake pressure adjustment device 12 can thus use already available data v, T. It is understood that the emergency brake pressure adjustment device can also be connected in a suitable manner to other sensors and / or control devices in order to predict the time course of the load pressure signal Tmod used to control the emergency brake control valve device 14. Furthermore, an emergency brake pressure adjustment device 12 can also be designed to control a predefined temporal fallback emergency brake pressure curve in the event of a failure in the transmission of speed data v and / or load value data T.

[0041] As a further alternative, a data transmission connection can also be provided from the general brake control device 10 to the emergency brake pressure adjustment device 12. Control commands and information about the vehicle or brake status, for example, can be transmitted via this connection. Furthermore, load value data T can also be supplied to the emergency brake adjustment device 12 from outside, for example, via a suitable load value sensor. In addition, a transmission of load value data T from the brake control device 10 can be provided, which can serve, for example, for plausibility checks and / or to provide a redundancy level. In the event of an emergency braking, the electronic brake control device 10 can perform a plausibility check of the intended emergency braking via the data transmission connection.For example, the brake control device 10 can be connected to a suitable load value sensor that provides signals that are independent of the signals supplied to the emergency brake pressure adjustment device 12. If the electronic brake control device 10 determines that the emergency braking provided by the emergency brake pressure adjustment device 12 is implausible, for example, because it does not meet certain predefined plausibility criteria, the electronic brake control device 10 can suppress or prevent the emergency brake control valve device 14 from being activated by the emergency brake pressure adjustment device 12. In this case, a purely pneumatic emergency braking can be performed, in which the brake pressure may not be controlled directly as a function of speed.

[0042] It should be noted that the proposed time-controlled change in the brake pressure curve does not necessarily have to be applied when the brake pressure increases, nor does it necessarily have to be applied during emergency braking. Multiple points in time for different changes or a predetermined change curve of the brake pressure can also be calculated or predicted in advance. The time-dependent control can also be applied in other cases of a temporary or permanent reduction or increase in the brake pressure, thereby avoiding the effort associated with the timely and reliable detection of the speed. The proposed control can thus be used for any sudden, stepped, ramp-like, or other controlled change in the brake pressure of a braking device.

[0043] In summary, a device and a method for controlling a braking device, preferably an emergency braking device, of a rail vehicle have been described, wherein at least one predicted time or a period for a change in a braking pressure is determined based on speed data of the rail vehicle available when initiating a braking operation, and the change in the braking pressure is initiated in response to reaching the predicted time or period.

Claims

[1] Device for controlling a braking device of a rail vehicle to prevent the applied braking force from being absorbed by the frictional contact between wheel and rail, the braking operation being an emergency braking and a change being an increase in the braking pressure, comprising: - a time control device (12; 120) for determining at least one predicted time (t0) or period (UB t ) for a change in a brake pressure based on speed data of the rail vehicle available when initiating a braking operation, and - a brake pressure adjustment device (12; 122) for initiating the change in brake pressure when the predicted time or period is reached, - wherein the brake pressure adjusting device (12; 122) is designed to initiate the change in the brake pressure by outputting a modified load pressure signal (Tmod) to a brake control valve device (14), which in response thereto outputs a corresponding brake control pressure (Cn) to a pressure converter or a pressure booster for a pneumatic brake device, - wherein the brake pressure adjustment device (12) is designed such that it receives a speed signal (v) and a load pressure signal which indicates a load value (T) of the rail vehicle, characterized by , that - based on the last available speed signal (v) and taking into account the load (T), a braking time control device (120) determines a predicted time profile of the variable load pressure signal (Tmod) on the basis of an algorithm or a memory table and applies it to the brake control valve device (14) in order to achieve an optimized pressure switch for the initiated braking, - wherein the predicted time profile of the load pressure signal (Tmod) is fed as an electrical signal or in parameter form to a correspondingly controllable brake pressure adjustment device (122) which generates a correspondingly modulated load pressure signal (Tmod). [2] Device according to claim 1, wherein the time control device (12; 120) is designed, upon reaching the predicted time (t0) or period (UB t) to generate a trigger signal (UTr) for changing the brake pressure, and wherein the brake pressure adjusting device (12; 122) initiates the change in the brake pressure in response to detection of the trigger signal (UTr). [3] Device according to one of the preceding claims, wherein the brake pressure adjusting device (12; 122) is designed to initiate a sudden, step-like or ramp-like change in the brake pressure. [4] Braking system for a rail vehicle, comprising a device according to one of claims 1 to 3.

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