Patent Application
20240300465
The disclosure relates to a redundancy valve assembly for redundantly supplying a redundant brake pressure into a service brake pressure path of an electronically controllable pneumatic brake system for a vehicle, preferably a utility vehicle, including a service control unit for controlling the electronically controllable pneumatic brake system in an operating mode, at least one service axle modulator which is connected to the service control unit and receives service braking signals from the latter and, based thereon, modulates a service brake pressure for a first axle, and a redundancy control unit for controlling the electronically controllable pneumatic brake system in a redundancy mode. Furthermore, the disclosure also relates to a vehicle, preferably a utility vehicle, including at least a first axle and a second axle and an electronically controllable pneumatic brake system. In addition, the disclosure relates to a method for controlling an electronically controllable pneumatic brake system.
Concepts for the redundant modulation of a brake pressure are intended to enable redundant braking of the vehicle, particularly in the event of a fault in a brake system that partially or completely prevents the modulation of a service brake pressure. Known concepts for redundant modulation of a brake pressure generally use partially redundant components and partially existing components to modulate the brake pressure. For example, US 2019/0152459 discloses a system in which, in the event that a central control unit fails, which would otherwise electronically actuate a front axle modulator, a bypass valve pneumatically controls a redundancy pressure, which is then provided to the front axle modulator in order to achieve redundant pneumatic modulation of the front axle brake pressure. In general, US 2019/0152459 discloses an electronically controllable pneumatic brake system with at least two brake circuits, wherein an electrically and pneumatically controllable control valve is assigned to at least one of the at least two brake circuits and an electrically controllable parking brake valve is assigned to a further one of the at least two brake circuits, for specifying brake pressures for actuating wheel brakes of the respective brake circuit. A first control unit is provided, which is configured to electrically modulate the respective control valve in dependence on an automatically requested vehicle setpoint deceleration or an actuation specified by the driver via a brake pedal. Furthermore, a second control unit is provided which is configured to control the parking brake valve electrically depending on the automatically requested vehicle setpoint deceleration if electrical actuation of the respective control valve is prevented in order to form an electronically pneumatically controlled redundancy. Furthermore, a bypass valve associated with one of the control valves is provided and is configured to pneumatically modulate the associated control valve, wherein the pneumatic modulation takes place in dependence on the automatically requested vehicle setpoint deceleration or in dependence on the brake pedal actuation performed by the driver if electrical actuation of the respective control valve is prevented.
However, such a configuration requires that the corresponding redundancy connection of the control valve, namely the front axle modulator or rear axle modulator, is functional. As a result, such a solution is dependent on one of the main actuators of the control valve, namely the front axle modulator or rear axle modulator, being functional.
There are also other approaches that create a fully redundant brake system, as disclosed in US 2022/0144232 and WO 2020/187569 in particular. According to the teaching there, all relevant system elements are duplicated and a fully redundant brake system is thus created. The brake systems are then combined via select high valves on the brake actuators. However, this solution has the fluidic disadvantage that the primary system can only modulate the brake pressure via the select high valves on the brake actuators, and therefore not directly. In addition, the complete duplication of the individual components also results in an increased installation space requirement.
The object of the present disclosure is therefore to further improve the existing systems, which basically function well, and to achieve a high level of availability while at the same time providing fluidically advantageous solutions that have fewer or no repercussions on the primary system.
The object is achieved in a first aspect of the disclosure in a redundancy valve assembly of the type mentioned at the outset in that the assembly has: a service brake pressure connection for receiving a service brake pressure from a service brake pressure modulator, a redundancy brake pressure connection for receiving a redundancy brake pressure from a redundancy brake pressure modulator, and a brake actuator connection for connecting at least one brake actuator, wherein the redundancy valve assembly is electrically actuatable in order to selectively modulate the service brake pressure or the redundancy brake pressure at the brake actuator connection.
In contrast to the prior art, in which one or more select high valves or other types of new shuttle valves are used to couple in a redundancy brake pressure in a service brake pressure path, for example directly on the brake actuator, and control through, purely mechanically, in particular the higher of two pressures applied to two different connections, the invention uses the redundancy valve assembly, which can be actuated electrically in order to modulate optionally the service brake pressure or the redundancy brake pressure at the brake pressure actuator connection. It is intended that the service brake pressure and the redundancy brake pressure are provided at two different connections of the redundancy valve assembly and are therefore, in particular, independent of each other. The service brake pressure is provided by a service brake pressure modulator and the redundancy brake pressure is provided by a redundancy brake pressure modulator. The modulation of the redundancy brake pressure via the redundancy valve assembly at the brake actuator connection is therefore not dependent on a main actuator of the service brake pressure modulator being functional. Rather, it is sufficient if the redundancy brake pressure modulator and the redundancy valve assembly are functional. An electrically actuatable redundancy valve assembly also makes it possible to modulate the service brake pressure or the redundancy brake pressure at the brake actuator connection independently of a possible fault. This means that, even in cases where there is no fault in the vehicle, the redundancy brake pressure can be modulated at a brake pressure actuator connection, for example to test the functionality, ensure the operability of valves, increase the service life of components, compensate for wear or implement other measures that positively influence efficiency, such as air consumption. In a first embodiment, the redundancy valve assembly has a solenoid valve unit which is connected at least to the service brake pressure connection and the redundancy brake pressure connection and is switchable by at least one first switching signal, wherein the service brake pressure or the redundancy brake pressure at the brake actuator connection is modulated in dependence on the at least first switching signal. The solenoid valve unit can preferably have one or more electromagnetically switchable valves, such as preferably monostable or bistable valves.
In an embodiment, the solenoid valve unit has an electromagnetic service pilot valve and an electromagnetic redundancy pilot valve, wherein the service pilot valve is switchable by the first switching signal and provides a first pilot pressure, and the redundancy pilot valve is switchable by a second switching signal and provides a second pilot pressure. One or more main valves can then be subsequently switched on the basis of the first and second pilot pressure in order to enable either the service brake pressure or the redundancy brake pressure to be controlled through to the brake actuator connection.
Preferably, the service pilot valve has a first service pilot valve connection connected to the service brake pressure connection, a second service pilot valve connection connected to the redundancy brake pressure connection, and a third service pilot valve connection modulating the first pilot pressure. Depending on the first switching signal, the service pilot valve connects either the first service pilot valve connection or the second service pilot valve connection to the third service pilot valve connection. Preferably, in a first switching position, the first service pilot valve connects the second service pilot valve connection to the third service pilot valve connection, and, in a second switching position, the first service pilot valve connects the first service pilot valve connection to the third service pilot valve connection. Preferably, the first service pilot valve is de energized in the first switching position.
The redundancy pilot valve is preferably configured in the same way as the service pilot valve. The redundancy pilot valve preferably has a first redundancy pilot valve connection connected to the redundancy pressure connection, a second redundancy pilot valve connection connected to the service brake pressure connection, and a third redundancy pilot valve connection that modulates the second pilot pressure. The redundancy pilot valve preferably connects either the first redundancy pilot valve connection or the second redundancy pilot valve connection to the third redundancy pilot valve connection, depending on the second switching signal. Preferably, the redundancy pilot valve connects the second redundancy pilot valve connection to the third redundancy pilot valve connection in a first switching position and the first redundancy pilot valve connection to the third redundancy pilot valve connection in a second switching position. Preferably, the redundancy pilot valve is de energized in the first switching position and is moved to the second switching position by providing the second switching signal. In one variant, the first or second pilot pressure can be modulated directly at the brake actuator connection as a volume pressure. In this respect, it can be provided that the service pilot valve and the redundancy pilot valve ultimately connect the service brake pressure connection or redundancy brake pressure connection directly to the brake actuator connection, and thus control the service brake pressure or redundancy brake pressure. The first pilot pressure then preferably corresponds to the service brake pressure and the second pilot pressure preferably corresponds to the redundancy brake pressure.
In an embodiment, however, it can also be provided that the redundancy valve assembly has a main valve unit which is connected to the service brake pressure connection, the redundancy brake pressure connection, and the brake actuator connection for optionally shutting out the service brake pressure or the redundancy brake pressure. This means that the main valve unit is preferably in a normally open switching position, so that, when the main valve unit is not actuated, the service brake pressure or redundancy brake pressure from the respective service brake pressure connections and redundancy brake pressure connection can be controlled through by the main valve unit and modulated at the brake actuator connection. The main valve unit can then be switched to either control the service brake pressure through to the brake actuator connection or to control the redundancy brake pressure through to the brake actuator connection. In the actuated state, at least one of these two pressures is preferably shut out.
The main valve unit preferably has a service main valve, which has a first service main valve connection connected to the service brake pressure connection and a second service main valve connection connected to the brake actuator connection. Preferably, the service main valve separates the first service main valve connection and the second service main valve connection in a blocking position and connects the first service main valve connection and the second service main valve connection by pressurized fluid in a passage position. Preferably, the main valve unit also has a redundancy main valve, which has a first redundancy main valve connection connected to the redundancy brake pressure connection and a second redundancy main valve connection connected to the brake actuator connection, wherein the redundancy main valve preferably separates the first redundancy main valve connection and the second redundancy main valve connection in a blocking position and connects the first redundancy main valve connection and the second redundancy main valve connection to one another by pressurized fluid in a passage position. The service main valve and the redundancy main valve can be of identical or different configuration, in one or two structural units.
Preferably, the service main valve is switchable pneumatically. For this purpose, the service main valve preferably has a service control connection which is connected to the solenoid valve unit to receive the first pilot pressure, wherein the service main valve is spring loaded into the blocking position. It may be provided that the service main valve switches from the blocking position to the release position when the first pilot pressure exceeds a certain first threshold value. It can also be provided that the service main valve switches from the release position to the closed position when the first pilot pressure exceeds a second threshold value. In order to form an operationally reliable fallback level, the service main valve should be configured so that it is in a release position when no first pilot pressure is being modulated but the service brake pressure is present at the service brake pressure connection. This is because the first pilot pressure can be modulated by actively switching the solenoid valve unit and the service brake pressure can be actively shut out in this way. In normal operation, however, the service main valve should be in a release position so that the service brake pressure can be controlled through and made available at the brake actuator connection in normal operation.
The same applies for the redundancy main valve. This is also preferably pneumatically switchable and preferably has a redundancy control connection. The redundancy control connection is preferably connected to the solenoid valve unit, in particular the redundancy pilot valve, to receive the second pilot pressure. Preferably, the redundancy main valve is spring loaded into the blocking position. In normal operation, the redundancy brake pressure should be shut out so that only the service brake pressure can be controlled through from the service brake pressure connection to the brake actuator connection. Only if the service brake pressure cannot be provided or cannot be provided correctly due to a fault should the service brake pressure connection be closed and the redundancy brake pressure should be controlled through and provided at the brake actuator connection.
In an embodiment, both the first switching signal and the second switching signal are provided by a redundancy control unit. This further develops the aspect of the operationally reliable fallback level. In the event that a fault occurs in a service level, a service level may not be able to provide the first switching signal or the second switching signal correctly or at all. If a redundancy level is then to take over control, the service brake pressure can be shut out and the redundancy brake pressure can be controlled through and provided at the brake actuator connection by a redundancy control unit providing the switching signals in the correct manner for operation.
In a further embodiment, an ABS valve is connected upstream of the service brake pressure connection so that an ABS modulated service brake pressure is provided to the service brake pressure connection. A conventional ABS valve can be provided here as an ABS valve, which reduces the service brake pressure depending on signals from one or more wheel speed sensors. In this case, an ABS modulated service brake pressure is a service brake pressure that is temporarily reduced by an ABS valve in accordance with this requirement in order to prevent a wheel from locking. By already providing an ABS modulated service brake pressure at the service brake pressure connection, in particular because an ABS valve is connected downstream of, or is integrated in, the service brake actuator, which controls the service brake pressure at the service brake pressure connection, the service brake pressure, which is modulated at the service brake pressure connection, can be controlled through by the redundancy valve assembly and modulated at the brake actuator connection and provided by this directly at the brake actuator, while at the same time preventing brake locking.
An ABS valve can also be connected upstream of the redundancy brake pressure connection in order to provide the redundancy brake pressure in ABS modulated form.
Additionally or alternatively, the redundancy valve assembly as a whole can also be configured as an ABS valve and can be provided to modulate the service brake pressure received at the service brake pressure connection in an ABS modulated manner at the brake actuator connection. For this purpose, the redundancy valve assembly can temporarily reduce the service brake pressure received at the service brake pressure connection in dependence on one or more signals from one or more wheel speed sensors in order to prevent a wheel from locking. For this purpose, the redundancy valve assembly can have one or more bleed valves that allow the service brake pressure to be reduced temporarily.
In a further embodiment, the redundancy valve assembly includes a rapid bleed valve for venting the pressure modulated at the brake actuator connection. The pressure modulated at the brake actuator connection can be the service brake pressure, the redundancy brake pressure, or a pressure derived from these. The pressure controlled at the brake actuator connection is preferably supplied directly to the brake actuator. By providing the redundancy valve assembly with a rapid bleed valve that is suitable for venting the pressure controlled at the brake actuator connection, it is possible on the one hand to quickly vent the brake actuator and thus quickly release the brake, and on the other hand to use the rapid bleed valve to achieve ABS control for only briefly and temporarily reducing the pressure modulated at the brake actuator connection.
Preferably, the rapid bleed valve is connected to the redundancy brake pressure connection in such a way that, optionally, the redundancy brake pressure can be modulated and the brake actuator connection can be vented via the rapid bleed valve. The rapid bleed valve therefore forms a venting path for the brake actuator connection, but allows the redundancy brake pressure to be modulated via this venting path of the brake actuator connection. The venting path of the brake actuator connection can then preferably be brought into connection with the service brake pressure connection or can be connected by pressurized fluid. The redundancy brake pressure can therefore be controlled via the venting path of the rapid bleed valve in order to be provided at the brake actuator connection in this way.
For this purpose, the rapid bleed valve could have a first rapid bleed valve connection connected to the redundancy brake pressure connection, a second rapid bleed valve connection connected to the main valve unit, and a third rapid bleed valve connection connected to a venting means.
In a further embodiment, it is provided that the service pilot valve is switchable by a third switching signal and the redundancy pilot valve is switchable by a fourth switching signal, which are provided by a service control unit. In this embodiment, the service pilot valve and the redundancy pilot valve are preferably Y wired, specifically both to the redundancy control unit and to the service control unit. This means that both the service pilot valve and the redundancy pilot valve can be switched independently of each other both by the redundancy control unit and by the service control unit. With regard to the service pilot valve and the redundancy pilot valve, the service control unit and the redundancy control unit can completely replace each other, so that the range of functions is increased.
In one variant, the service pilot valve can have a first electromagnet at which both the first switching signal and the third switching signal can be provided. Preferably, the redundancy pilot valve has a second electromagnet at which both the second switching signal and the fourth switching signal can be provided. The first, second, third and fourth switching signals are therefore each modulated at the same electromagnet and can both act on it.
Alternatively, it can also be provided that the service pilot valve has a first electromagnet at which the first switching signal can be provided and a third electromagnet at which the third switching signal can be provided. Preferably, the redundancy pilot valve analogously includes a second electromagnet at which the second switching signal can be provided and a fourth electromagnet at which the fourth switching signal can be provided. Each electromagnet is assigned its own switching signal here and, unlike in the example described above, a single electromagnet is not controlled with two switching signals. In this way, a better separation of functions can be achieved.
In a further embodiment, the solenoid valve unit has an electromagnetic inlet pilot valve and an electromagnetic outlet pilot valve, wherein the inlet pilot valve is switchable by an inlet switching signal and provides a third pilot pressure and the outlet pilot valve is switchable by an outlet switching signal and provides a fourth pilot pressure. Preferably, the inlet switching signal and the outlet switching signal are provided by a service control unit. The first switching signal and the second switching signal can also be provided by the redundancy control unit. In this respect, a redundancy valve assembly is created which has separate valves for the service level and the redundancy level, namely the service pilot valve and the redundancy pilot valve for the redundancy level and the inlet pilot valve and the outlet pilot valve for the service level.
It can be preferred here that the inlet pilot valve has a first inlet pilot valve connection connected to the service brake pressure connection, a second inlet pilot valve connection connected to a venting means, and a third inlet pilot valve connection that controls the third pilot pressure. The inlet pilot valve preferably connects either the first inlet pilot valve connection or the second inlet pilot valve connection to the third inlet pilot valve connection, depending on the inlet switching signal. Preferably, in a first switching position, the inlet pilot valve connects the second inlet pilot valve connection to the third inlet pilot valve connection, and in a second switching position, the first inlet pilot valve connection to the third inlet pilot valve connection. Preferably, the inlet pilot valve is de energized in the first switching position and switches to the second switching position when the inlet switching signal is provided.
Furthermore, the outlet pilot valve preferably has a first outlet pilot valve connection connected to a or the venting means, a second outlet pilot valve connection connected to the service brake pressure connection, and a third outlet pilot valve connection controlling the fourth pilot pressure. The outlet pilot valve preferably connects either the first outlet pilot valve connection or the second outlet pilot valve connection to the third outlet pilot valve connection, depending on the outlet switching signal. Preferably, the outlet pilot valve connects the second outlet pilot valve connection to the third outlet pilot valve connection in a first switching position, and the first outlet pilot valve connection to the third outlet pilot valve connection in a second switching position. Preferably, the outlet pilot valve is de-energized in the first switching position and switches to the second switching position when the outlet switching signal is provided.
Advantageously, in particular in embodiments with inlet and outlet pilot valves, it is further provided that the service pilot valve has a first service pilot valve connection connected to the service brake pressure connection, a second service pilot valve connection connected to a or the venting means, and a third service pilot valve connection controlling the first pilot pressure, wherein the service pilot valve connects either the first service pilot valve connection or the second service pilot valve connection to the third service pilot valve connection depending on the first switching signal. Preferably, the redundancy pilot valve has a first redundancy pilot valve connection connected to a or the venting means, a second redundancy pilot valve connection connected to the service brake pressure connection, and a third redundancy pilot valve connection controlling the second pilot pressure, wherein the redundancy pilot valve connects either the first redundancy pilot valve connection or the second redundancy pilot valve connection to the third redundancy pilot valve connection depending on the second switching signal.
In such embodiments, it is preferably further provided that the first pilot pressure and the third pilot pressure can be modulated via a first shuttle valve on the main valve unit, and/or the second pilot pressure and the fourth pilot pressure can be modulated via a second shuttle valve on the main valve unit. In this way, the pilot pressure modulated by the service pilot valve and the inlet pilot valve can be combined and provided alternately at the main valve unit, in particular and preferably at the service main valve. Similarly, the pilot pressures modulated by the redundancy pilot valve and outlet pilot valve can be combined and alternately controlled via the second shuttle valve on the main valve unit, specifically in particular on the redundancy main valve of the main valve unit. Since the first and second shuttle valves in this embodiment are only used to activate the main valves and thus basically switch between operating and redundancy mode, the performance and dynamics of the system do not suffer. In order to ensure the operability of the shuttle valves or even just to be able to test them, it is possible to actively switch between the different modes by providing the corresponding switching signals.
In a further embodiment, the redundancy valve assembly has a pressure sensor for detecting the pressure modulated at the brake actuator connection. In this way, it is possible to verify whether the main valve unit or the pilot valves of the redundancy valve assembly are functioning properly. A control loop can also be established in this way.
In a second aspect of the disclosure, the object mentioned at the outset is achieved in an electronically controllable pneumatic brake system for a vehicle, preferably a utility vehicle, having a service control unit for controlling the electronically controllable pneumatic brake system in an operating mode, at least one service axle modulator which is connected to the service control unit and receives service braking signals from the latter and controls a service brake pressure for a first axle on the basis thereof, a redundancy control unit for controlling the electronically controllable pneumatic brake system in the event of redundancy, and at least one redundancy axle modulator which is connected to the redundancy control unit and receives redundancy braking signals from the latter and controls a redundancy brake pressure for the first axle on the basis thereof, in that at least one redundancy valve assembly is provided according to one of the embodiments of a redundancy valve assembly according to the first aspect of the disclosure described above. In this case, the service brake pressure connection of the redundancy valve assembly is connected to the service axle modulator and receives the service brake pressure from the latter. The redundancy brake pressure connection is also connected to the redundancy axle modulator and receives the redundancy brake pressure from it. Lastly, the brake actuator connection of the redundancy valve assembly is connected to a first service brake actuator on the first axle.
It should be understood that the redundancy valve assembly according to the first aspect of the disclosure and the electronically controllable pneumatic brake system according to the second aspect of the disclosure have the same and similar sub aspects. In this respect, full reference is made to the above description of the redundancy valve assembly according to the first aspect of the disclosure for embodiments and their advantages.
Preferably, the at least one redundancy valve assembly is connected to the redundancy control unit and receives the first switching signal and the second switching signal from the redundancy control unit. It may also be provided that the redundancy valve assembly has its own intelligence and in this respect receives a request signal from the redundancy control unit, which then converts the redundancy valve assembly's own intelligence into the first and second switching signals. Furthermore, it is conceivable and preferred that the at least one redundancy valve assembly is integrated with the redundancy control unit to form a module.
Furthermore, the at least one redundancy valve assembly is preferably connected to the service control unit and receives the third and fourth switching signals from the latter. In the event that the redundancy valve assembly has an inlet pilot valve and an outlet pilot valve, it preferably also receives the inlet switching signal and the outlet switching signal from the service control unit. Again, it may be provided that the redundancy valve assembly has its own intelligence which determines these signals or is integrated with the service control unit to form a module.
In a further embodiment, it is provided that the electronically controllable pneumatic brake system has at least one first wheel speed sensor on the first axle, which is connected both to the service control unit and to the redundancy control unit and provides a first wheel speed signal to the latter. Preferably, the first switching signal and the second switching signal and possibly also further switching signals for the redundancy valve unit are generated and provided based on the first wheel speed signal. If further wheel speed sensors are present, these are also included. In this way, the redundancy valve unit can control the service brake pressure or redundancy brake pressure depending on the wheel speed and thus implement ABS functionality. Preferably, the third switching signal, the fourth switching signal, the inlet switching signal and/or the outlet switching signal are therefore also generated and provided by the service control unit based on the first wheel speed signal.
In an embodiment, the redundancy valve assembly is arranged on the first service brake actuator or installed adjacent to it. The redundancy valve assembly is preferably provided close to the wheel, and the first service brake actuator is preferably connected directly to the brake actuator connection of the redundancy valve assembly without further piping or tubing. In this way, high dynamics can be achieved and further fault sources can be avoided.
According to an embodiment, at least one redundancy valve assembly according to one of the embodiments of the redundancy valve assembly according to the first aspect of the disclosure described above is provided on each axle of the vehicle. In this way, axle based redundant braking can be achieved via the redundancy valve assembly of the vehicle. Preferably, a separate redundancy valve assembly is provided on each service brake actuator. In this way, the redundancy valve assembly can modulate the brake pressure redundantly for each wheel. It is also possible, for example, for a redundancy valve assembly to be provided on each service brake actuator on the front axle, wherein a single redundancy valve assembly is only provided for the rear axle. In the front axle, wheel oriented modulation would thus be permitted, while only axle oriented modulation is realized at the rear axle.
In an embodiment, a second redundancy valve assembly is provided, which is configured according to one of the embodiments of the redundancy valve assembly according to the first aspect of the disclosure described above, wherein the service brake pressure connection of the second redundancy valve assembly is connected to the service axle modulator and receives the service brake pressure from it and the redundancy brake pressure connection of the second redundancy valve assembly is connected to the redundancy axle modulator and receives the redundancy brake pressure from it. The brake actuator connection of the second redundancy valve assembly is preferably connected to at least one second service brake actuator on the first axle.
In a further embodiment, the electronically controllable pneumatic brake system also includes a second service axle modulator which is connected to the service control unit and receives service braking signals from the latter, and based thereon modulates a second service brake pressure for a second axle. Furthermore, the brake system includes a second redundancy axle modulator, which is connected to the redundancy control unit and receives redundancy braking signals from the latter and, based thereon, modulates a second redundancy brake pressure for the second axle. In this embodiment, the electronically controllable pneumatic brake system preferably has at least one third redundancy valve assembly according to one of the embodiments of a redundancy valve assembly according to the first aspect of the disclosure described above. Here, the service brake pressure connection of the third redundancy valve assembly is preferably connected to the second service axle modulator and receives the second service brake pressure from it, and the redundancy brake pressure connection of the third redundancy valve assembly is connected to the second redundancy axle modulator and receives the second redundancy brake pressure from it. Furthermore, the brake actuator connection of the third redundancy valve assembly is preferably connected to at least one third service brake actuator on the second axle. It can also be connected additionally to a fourth service brake actuator of the second axle or other service brake actuators on the second axle or another axle, such as a lift axle or the like.
In a third aspect, the disclosure achieves the above described object in a vehicle, preferably a utility vehicle of the above described type, including at least a first axle and a second axle and an electronically controllable pneumatic brake system, in that the electronically controllable pneumatic brake system is configured in accordance with one of the embodiments of the electronically controllable pneumatic brake system described above in accordance with the second aspect of the disclosure.
It should be understood that the electronically controllable pneumatic brake system according to the second aspect of the disclosure and the vehicle according to the third aspect of the disclosure have the same and similar sub aspects. In this respect, full reference is made to the above description for further embodiments and their advantages.
The disclosure achieves the object in a fourth aspect by a method for controlling an electronically controllable pneumatic brake system including the following steps: in an operating mode of the electronically controllable pneumatic brake system: modulating a service brake pressure by a service brake pressure modulator at a service brake pressure connection of a redundancy valve assembly, actuating the redundancy valve assembly by a service control unit based on first wheel speed signals and thereby preferably providing slip controlled modulation of the service brake pressure at a brake actuator connection of the redundancy valve assembly; and in a redundancy mode of the electronically controllable pneumatic brake system: modulating a redundancy brake pressure by a redundancy brake pressure axle modulator at a redundancy brake pressure connection of the redundancy valve assembly, and actuating the redundancy valve assembly by a redundancy control unit based on the first wheel speed signals and thereby preferably providing slip controlled modulation of the redundancy brake pressure at the brake actuator connection.
The method according to the fourth aspect of the disclosure is preferably implemented in an electronically controllable pneumatic brake system according to the second aspect of the disclosure. Preferably, the redundancy valve assembly referred to in the method according to the fourth aspect of the disclosure is a redundancy valve assembly according to one of the embodiments of a redundancy valve assembly according to the first aspect of the disclosure described above.
It should be understood that the method according to the fourth aspect of the disclosure, the redundancy valve assembly according to the first aspect of the disclosure and the electronically controllable pneumatic brake system according to the second aspect of the disclosure have the same and similar sub aspects. In this respect, full reference is made to the above description. In particular, functional features described above can also form method steps in the context of the method according to the fourth aspect of the disclosure and the functions described above can be implemented and executed in the context of the method.
The invention will now be described with reference to the drawings wherein:
A redundancy valve assembly 1 for redundantly supplying a redundant brake pressure into a service brake pressure path of an electronically controllable pneumatic brake system 204 (cf.
A service brake pressure p1 is provided at the service brake pressure connection 4, as will be described in greater detail later with reference to
In the embodiment shown in
Specifically, in the embodiment shown here, the solenoid valve unit 10 includes a service pilot valve 14, which is configured here as a monostable 3/2 way valve. The service pilot valve 14 includes a first service pilot valve connection 14.1, which is connected to the service brake pressure connection 4 and receives the service brake pressure p1 from it. The service pilot valve includes a second service pilot valve connection 14.2, which is connected to the redundancy brake pressure connection 6 and receives the redundancy brake pressure p2. The third service pilot valve connection 14.3 is connected to a main valve unit 12 in the embodiment shown here, but could also be connected to the brake actuator connection 8 in other embodiments. The service pilot valve 14 can alternately connect the first service pilot valve connection 14.1 or the second service pilot valve connection 14.2 to the third service pilot valve connection 14.3 and thus alternately modulate the service brake pressure p1 or the redundancy brake pressure p2 at the third service pilot valve connection 14.3. In the first switching position shown in
Furthermore, the solenoid valve unit 10 includes a redundancy pilot valve 16. The redundancy pilot valve 16 is configured as a monostable 3/2 way valve and has a first redundancy pilot valve connection 16.1, which is connected to the redundancy brake pressure connection 6 and receives redundancy brake pressure p2 from it. A second redundancy pilot valve connection 16.2 is connected to the service brake pressure connection 4 and receives service brake pressure p1 from it. A third redundancy pilot valve connection 16.3 is connected to the main valve unit 12 in the embodiment shown in
The main valve unit 12 is connected in such a way that when the service brake pressure p1 is modulated at the service brake pressure connection 4 and the service pilot valve 14 is simultaneously in the first switching position, the service brake pressure p1 is modulated at the brake actuator connection 8. Conversely, when the redundancy pilot valve 16 is in the first switching position and the service brake pressure p1 at the service brake pressure connection 4 is modulated, the redundancy brake pressure connection 6 is blocked so that the redundancy brake pressure p2 cannot be controlled through to the brake actuator connection 8. This prevents the pressures from being duplicated. The opposite can also be achieved by switching the service pilot valve 14 or redundancy pilot valve 16 to a different switching position.
In the embodiment shown here (
The redundancy main valve 20 is configured correspondingly to the service main valve 18. It is also configured as a pneumatically switchable 2/2 way valve and has a first redundancy main valve connection 20.1 and a second redundancy main valve connection 20.2, which are separated in a blocking position 20A and are pneumatically connected to each other in a passage position 20B. The first redundancy main valve connection 20.1 is connected to the redundancy brake pressure connection 6 and receives redundancy brake pressure p2 from it. The second redundancy main valve connection 20.2 is connected to the brake actuator connection 8 in order to be able to control the redundancy brake pressure p2 at this connection. The redundancy main valve 20 can be switched by a second control pressure pS2, which is provided by the solenoid valve unit 10, in dependence on the first and/or second switching signal S1, S2, from the blocking position 20A to the passage position 20B, and vice versa. The redundancy main valve 20 is spring loaded into the blocking position 20A. The redundancy main valve 20 also includes a first redundancy feedback connection 20.4, at which the pressure applied to the redundancy brake pressure connection 6, in particular the redundancy brake pressure p2, is modulated. If this exceeds a third threshold value, the redundancy main valve 20 can be switched from the blocking position 20A to the passage position 20B by overcoming the spring force of the return spring. However, if the second control pressure pS2 is simultaneously modulated at the redundancy control connection 20.3 and this exceeds a fourth threshold value, the redundancy main valve 20 cannot be switched to the passage position 20B, but remains in the blocking position 20A. In this way, the redundancy brake pressure p2 can be shut out. The second control pressure pS2 is then shut out when the service brake pressure p1 is shut out and the redundancy pilot valve 16 is simultaneously in the first switching position shown in
In normal driving operation, the service brake pressure p1 should typically be modulated at the brake actuator connection 8. For this purpose, neither the first nor the second switching signal S1, S2 should be deactivated if possible, so that the service main valve 18 can switch to the passage position 18B and the redundancy main valve 20 remains in the blocking position 20A.
However, if the redundancy brake pressure p2 is now to be modulated at the brake actuator connection 8, at least the redundancy pilot valve 16 should be moved to the second switching position, not shown in
The first and second switching signals S1, S2 are preferably provided by a redundancy control unit, but can also be provided by a service control unit, or the first switching signal S1 is provided in a service control unit and the second switching signal S2 is provided by a redundancy control unit, or vice versa. The service pilot valve 14 and the redundancy pilot valve 16 can be supplied by one or two independent voltage sources, or are both supplied with voltage redundantly. It can also be provided that the service brake pressure p1 and the redundancy brake pressure p2 are supplied from the same or from two different, preferably independent, compressed air supplies.
The ABS valve 100 has an ABS pilot control unit 104 and an ABS main valve unit 106. The ABS pilot control unit 104 receives a third and a fourth switching signal S3, S4, which are modulated based on wheel speed signals. The ABS main valve unit 106 includes an ABS inlet valve 124 and an ABS outlet valve 126, which are pneumatically controlled. The ABS inlet valve 124 is connected to the brake modulator connection 102 and can modulate the ABS modulated service brake pressure p1ABS by switching. The ABS outlet valve 126 is also pneumatically controlled and connected to a venting means 3 in order to vent the ABS modulated service brake pressure p1ABS or also the service brake pressure p1 if this is not ABS modulated. For this purpose, the ABS outlet valve 126 is then switched to a passage position. The ABS inlet valve 124 and the ABS outlet valve 126 are switched based on the ABS pilot control unit 104, which in the embodiment shown in
In addition to the advantage that an ABS modulated service brake pressure p1ABS can be provided at the service brake pressure connection 4, the ABS valve 100 also has the advantage that the service brake pressure p1 can be vented via the venting means 3 of the ABS valve 100. This is relevant if compressed air from the brake pressure actuator, which is connected to the brake actuator connection 8, is to be vented in order to reduce the braking force.
In the embodiment shown in
While the ABS valve 100 was connected upstream of the service brake connection 4 in the second embodiment shown in
In order to be able to vent the brake actuator connection 8, a rapid bleed valve 22 is advantageously provided in the embodiment shown here, which is integrated into the redundancy valve module housing 2 in the embodiment shown in
In this case, the redundancy brake pressure p2 can be modulated via the first rapid bleed valve connection 22.1, which is closed by a valve element during normal operation. This valve element then comes out of its blocking position when the redundancy brake pressure p2 is provided and the valve element is thereby pressed into a passage position. The service brake pressure p1 can then flow from the first rapid bleed valve connection 22.1 to the third rapid bleed valve connection 22.3 and from there, via the redundancy main valve 20, which is then switched to the passage position 20B, due to the modulation of the redundancy brake pressure p2 at the first redundancy feedback connection 20.4, at the brake actuator connection 8. Reference sign 40 in
The electronically controllable pneumatic brake system 204 has a service level B1 and at least one first redundancy level B2.
In the service level B1, the electronically controllable pneumatic brake system 204 includes an electronic service control unit 110 that controls the electronically controllable pneumatic brake system 204 in the service level B1. The electronic service control unit 110 is connected to an autonomous driving unit 230 via a vehicle BUS 228 and receives brake request signals SA from the autonomous driving unit. In addition, the service control unit 110 is connected to a first voltage source 234 via a first supply line 232 and is supplied with electrical voltage by the first voltage source. The electronic service control unit 110 converts the brake request signals SA and, based thereon, modulates service braking signals SB at a first service axle modulator 112, which is configured here as a front axle modulator 113. The first service axle modulator 112 is provided here for the first axle A1, namely the front axle VA, and can thus also be referred to as the front axle modulator 113. The first service axle modulator 112 is connected to the second service compressed air supply 226 and receives supply pressure pV from it. Specifically, the supply pressure pV is provided at a first supply connection 120 of the first service axle modulator 112. Based on the received service braking signals SB, the first service axle modulator 112 controls a first service brake pressure p1 at a first service brake pressure output 122a and a second service brake pressure output 122b. However, the first and second service brake pressure outputs 122a, 122b are only shown separately in
A redundancy valve assembly 1 according to the disclosure is provided on the right hand side in the direction of travel, connected to the first service brake pressure output 122a. This receives the service brake pressure p1 and modulates this to the first service brake actuator 207 or the first service brake actuator 208a in the event of operation. Specifically, the redundancy valve assembly 1 is configured here as an ABS valve 101 according to the embodiment of
A first wheel speed sensor 209 is also provided on the first axle A1, in this case the front axle VA, which provides first wheel speed signals SD to the service control unit 110. The service control unit 110 is configured to process the first wheel speed signals SD and to provide the third and fourth switching signals to the redundancy valve assembly 1 in order to achieve slip control or ABS modulation of the service brake pressure p1 and to prevent the front right wheel of the vehicle 200 from locking.
In the embodiment shown in
Power is supplied to the redundancy valve assembly 1 and the second redundancy valve assembly 1b with respect to the third and fourth switching signals S3, S4 via the first voltage source 234 in the embodiment shown here.
In order to brake the second axle A2 or the first and second rear axles HA1, HA2, the electronically controllable pneumatic brake system 204 in the service plane B1 includes a second service axle modulator 114, which is provided here for the first and second rear axles HA1, HA2 and can thus also be referred to as rear axle modulator 115. In the embodiment shown in
The second service axle modulator 114 is connected to the first service compressed air supply 224 and receives supply pressure pV therefrom. In accordance with the second and third service braking signals SB2, SB3, the second service axle modulator 114 modulates at least a second service brake pressure p3, but in the embodiment shown here it also modulates a third service brake pressure p5. In the embodiment shown in
In the embodiment shown in
Third to sixth wheel speed sensors 209c 209f are also provided on the first and second rear axles HA1, HA2 and respectively provide third to sixth wheel speed signals SD3, SD4, SD5, SD6 to the service control unit 110. This processes the third to sixth wheel speed signals SD3, SD4, SD5, SD6 and controls corresponding third and fourth switching signals S3, S4, as described above with reference to the redundancy valve assembly 1, also at the third to sixth redundancy valve assembly 1c 1f, but these are then dependent on the third to sixth wheel speed signals SD3 SD6. The corresponding third and fourth switching signals S3, S4 are referred to below as S3c S3f and S4c S4f. In this way, the second and third service brake pressures p3, p5 can be slip controlled or ABS modulated at the third to fifth service brake actuators 208c 208f in order to prevent the corresponding wheels from locking.
In the redundancy level B2, the electronically controllable pneumatic brake system 204 includes a redundancy control unit 140 which is intended to control the electronically controllable pneumatic brake system 204 in the event that the service level B1 has one or more faults, for example in the event of a power failure in the first voltage source 234, an electronic fault in the service control unit 110 or the like. The electronic redundancy control unit 140 is also connected to the autonomous driving unit 230 via the vehicle BUS 228 and also receives brake request signals SA from the latter. In contrast to the service control unit 110, the redundancy control unit 140 is connected to a second voltage source 238 via a second supply line 236 and is supplied with electrical voltage from this. The first and second voltage sources 234, 238 are independent of each other, so that a failure in the first voltage source 234 does not lead to a loss of the second voltage source 238, and vice versa. The electronic service control unit 110 and the electronic redundancy control unit 140 are therefore electrically independent of each other.
In order to be able to exchange signals, the service control unit 110 and the redundancy control unit 140 are connected to one another via a redundancy BUS 240. In this way, the redundancy control unit 140 can determine the availability of the service control unit 110 and only take over control of the electronically controllable pneumatic brake system 240 if the service control unit 110 is not available or no longer properly available. The service control unit 110 can also cause the redundancy control unit 140 to carry out one or more tests, in particular to modulate the redundancy pressure described above, in order to maintain the operability of valves and thus increase availability.
A redundancy axle modulator 142 is provided in the redundancy level B2 and is connected to the redundancy control unit 140 and receives redundancy braking signals SR from the latter. The redundancy axle modulator 142 is connected to a further second service compressed air supply 227, which is independent of the second service compressed air supply 226, so that the further second service compressed air supply 227 can also provide supply pressure pV if, for example, the second service compressed air supply 226 has failed. In other embodiments, however, the redundancy axle modulator 142 can also be connected to the second service compressed air supply 226 or the first service compressed air supply 224.
The redundancy axle modulator 142 controls a redundancy brake pressure p2 at a first redundancy brake pressure output 146a and a second redundancy brake pressure output 146b in dependence on the redundancy braking signals SR. The redundancy brake pressure p2 modulated at the first redundancy brake pressure output 146a is provided to the redundancy brake pressure connection 6 of the redundancy valve assembly 1. The redundancy brake pressure modulated at the second redundancy brake pressure output 146b is provided to the second redundancy valve assembly 1b on the left side of the front axle VA. The redundancy axle modulator 142 is again configured as a single channel axle modulator and the first and second redundancy brake pressure outputs 146a, 146b are shown separately in
The redundancy valve assembly 1 is connected to the redundancy control unit 140 and receives the first and second switching signals S1, S2 from the latter. In this way, the redundancy valve assembly 1 can be actuated by the redundancy control unit 140 in such a way that the redundancy brake pressure p2, which is modulated at the redundancy brake pressure connection 6, is controlled through and provided at the first service brake actuator 207. As can be seen in
In order to now also be able to brake the first and second rear axles HA1, HA2 of the vehicle 200 redundantly, the electronically controllable pneumatic brake system 204 in the redundancy level B2 also includes a second redundancy axle modulator 144, which is intended to replace the second service axle modulator 114. In the embodiment shown here (
The second redundancy axle modulator 144 modulates a second redundancy brake pressure p4 for the second axle A2. In addition, it also modulates a third redundancy brake pressure p6 for the second axle, in this case the first rear axle HAL. The second redundancy brake pressure p4 is intended for the right hand side of the vehicle and the third redundancy brake pressure p6 for the left hand side of the vehicle. In this respect, the second redundancy brake pressure p4 replaces the second service brake pressure p3 and the third redundancy brake pressure p6 replaces the third service brake pressure p5. The second and third redundancy brake pressures are provided at corresponding brake pressure connections of the fourth to sixth redundancy valve units 1c 1f, in accordance with the embodiments of the redundancy valve units described above. The redundancy control unit 140 also receives the third to sixth wheel speed signals SD3 SD6 of the third to sixth wheel speed sensors 209c 209f and modulates corresponding first and second switching signals, hereinafter referred to as S1c S1f, S2c S2f at the corresponding third to fourth redundancy valve units 1c 1f. The corresponding brake actuator connections (not provided with reference signs in
The service brake actuators 208a 208f can be vented as described above via the corresponding redundancy valve units 1c 1f.
Furthermore, the electronically controllable pneumatic brake system 204 is implemented with an additional redundancy level that functions purely pneumatically, as described, for example, in US 2020/0023827, in US 2022/0144232, in US 2022/0185251 or US 2022/0089137.
A significant difference in the embodiment shown in
A significant difference to the embodiment shown in
In order to control the first and third control pressure pS1, pS3 at the main valve unit 12, more precisely at the service main valve 18 and there at the service control connection 18.3, a first shuttle valve 28 is provided, which modulates the higher of the first and third control pressure pS1, pS3 at the service control connection 18.3. In the embodiment shown here, the first control pressure pS1 is also vented by the separate venting path 27, but could also be vented via the rapid bleed valve 22.
In addition, the outlet pilot valve 26 is also configured as a monostable 3/2 way solenoid valve, with a first outlet pilot valve connection 26.1, which is connected here to the separate venting path 27 and thus to the venting means 3, a second outlet pilot valve connection 26.2, which is connected to the service brake pressure connection 4 and receives service brake pressure p1, and a third outlet pilot valve connection 26.3, which is connected to the main valve unit 12. In the first monostable switching position shown in
Lastly,
It is understood that the foregoing description is that of the preferred embodiments of the invention and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2021 131 328.7 | Nov 2021 | DE | national |
This application is a continuation application of international patent application PCT/EP2022/080474, filed Nov. 2, 2022, designating the United States and claiming priority from German application 10 2021 131 328.7, filed Nov. 30, 2021, and the entire content of both applications is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2022/080474 | Nov 2022 | WO |
| Child | 18665964 | US |
