Redundant brake system

Abstract

The vehicle braking system comprises a first electronic control unit and a second electronic control unit, wherein the first electronic control unit is suitable for controlling a service braking function; a second electronic control unit adapted to control a parking brake function; a first axle pressure regulator pneumatically connected to at least one service brake chamber pneumatically connected associated with a first axle of the vehicle; a second axle pressure regulator pneumatically connected to at least one spring brake cylinder associated with a second axle of the vehicle; a parking brake unit also pneumatically connected to a spring brake cylinder associated with a second axle of the vehicle; the air supply unit is pneumatically connected with the first axle pressure regulator and the second axle pressure regulator; the first control unit is electrically connected to the first and second axle pressure regulators, the second control unit is electrically connected to the first axle pressure regulator, and the first and second electronic control units are integrated in the air supply unit. By means of this design, the safety level of the brake system can be increased, in particular for highly automated vehicles.

Description

TECHNICAL FIELD

[0001] The present invention relates to a braking system for a vehicle. BACKGROUND

[0002] Autonomous operation of commercial vehicles is a new field of innovation. More complex functions require a special hardware infrastructure. So far, commercial vehicle systems require the presence and attention of a driver. In the future, however, the driver's involvement in the vehicle driving control task will be reduced, so that automated systems will take over more important driving functions, which require a higher level of reliability, which in turn requires different types of system redundancy.

[0003] In addition, from a certain proportion of total production, for cost reasons, such vehicles are either designed without a cab at all or only with an emergency cab. Correspondingly, the driver interface, i.e. the brake pedal, can be simplified (e.g. the pneumatic device is cancelled) or even completely cancelled.

[0004] Today, commercial vehicles use electro-pneumatic or wire-controlled brake systems, in which the electronic part of the control is implemented as a single-loop control. In the event of a failure of the control electronics, the driver can still control the pneumatic part of the brake system by foot, as a dual-loop pneumatic backup system is still available.

[0005] In highly automated vehicles, the driver is no longer in the control loop, not even in the vehicle, the above-mentioned brake system will no longer be suitable, as there is no means of replacing the driver for brake control in the event of a failure of the single electronic control loop. SUMMARY

[0006] The technical problem of the present application is to improve the safety level of a brake system, in particular for highly automated vehicles.

[0007] The technical problem is solved by a brake system according to claim 1 and a vehicle according to claim 15. Other advantageous embodiments of the present application are the subject of the dependent claims.

[0008] The vehicle brake system according to the invention comprises:

[0009] a first electronic control unit, in particular adapted to control a service brake function;

[0010] a second electronic control unit, in particular adapted to control a parking brake function;

[0011] a first axle pressure regulator, which is pneumatically connected to at least one service brake chamber associated with a first axle of the vehicle;

[0012] a second axle pressure regulator, which is pneumatically connected to at least one spring brake cylinder associated with a second axle of the vehicle;

[0013] a parking brake unit, which is also pneumatically connected to a spring brake cylinder associated with the second vehicle axle;

[0014] an air supply unit, wherein the air supply unit is pneumatically connected to the first axle pressure regulator and to the second axle pressure regulator;

[0015] wherein the first control unit is electrically connected to the first axle pressure regulator and to the second axle pressure regulator,

[0016] the second electronic control unit is electrically connected to the first axle pressure regulator,

[0017] wherein the first electronic control unit and the second electronic control unit are integrated in the air supply unit.

[0018] Here, the first electronic control unit, which is mainly used for service braking, and the second electronic control unit, which is mainly used for parking brake application, have a redundancy function, i.e. when the second electronic control unit fails, the first electronic control unit can control the service braking and the parking brake application; when the first electronic control unit fails, the second electronic control unit can perform the control function of the service braking and the parking brake application. The integration into the air supply unit provides a compact and space-saving solution, thus forming a universal central electronic control unit.

[0019] Preferably, the parking brake unit, which mainly controls the parking brake application pressure, is also integrated in the air supply unit. In this way, since the parking brake unit is directly connected to the first electronic control unit and to the second electronic control unit, all signals can be exchanged between these units.

[0020] The parking brake unit can also be controlled by an external signal source.

[0021] Preferably, the first electronic control unit is also adapted to control the parking brake function and the second electronic control unit is also adapted to control the service brake function. Thus, a redundancy is achieved, so that even if one of the units fails, an effective braking is still ensured.

[0022] Preferably, a respective pressure control valve is provided between the first axle pressure regulator and the at least one service brake chamber, which control valve is connected to the first electronic control unit. This control valve has an ABS function, which is usually used for the front axle.

[0023] Preferably, the brake system further comprises a trailer control module, which is pneumatically connected to the air supply unit and electrically connected to the first electronic control unit. Thus, the control unit of the trailer control also has a redundancy, so that the brakes of the trailer can also be controlled accordingly.

[0024] Preferably, the braking system further comprises a first power supply unit connected to the first electronic control unit and a second power supply unit connected to the second electronic control unit. Thus, the power supply also has redundancy, the first and second electronic control units taking power from different sources, so that even if a power supply fails, at least one electronic control unit can work.

[0025] Preferably, the braking system further comprises a foot brake module adapted to receive service brake actuation brake commands. The foot brake module is connected to the first electronic control unit and to the second electronic control unit.

[0026] Preferably, the braking system further comprises a hand brake module adapted for parking brake actuation and also connected to the second electronic control unit.

[0027] In another embodiment, the parking brake unit is a separate unit, also acting as an additional control unit, optionally connected to a separate power supply. In this case, the braking system further comprises a hand brake module connected only to the parking brake unit. In this architecture, the parking brake unit can receive parking brake unit commands, but it is connected to the second electronic control unit.

[0028] Preferably, between the first electronic control unit and the first axle pressure regulator, between the first electronic control unit and the second axle pressure regulator, and between the second electronic control unit and the first axle pressure regulator, analog and digital electrical connections are provided.

[0029] Here, very fast and reliable communication is achieved between these components.

[0030] Preferably, the braking system further comprises a third electronic control unit adapted to provide highly automated driving braking demands and connected to the first electronic control unit and to the second electronic control unit. This unit can be used if the vehicle is equipped to calculate braking commands.

[0031] Preferably, the first electronic control unit and the second electronic control unit are adapted to perform any type of vehicle control function, in particular any type of braking demand. This makes the braking control very versatile.

[0032] Preferably, the first electronic control unit and the second electronic control unit are also adapted to receive braking demands from any external source, such as a vehicle control system. For example, a sensor can provide a signal when an obstacle is detected and immediate braking is required.

[0033] Preferably, the braking system further comprises a first electronic switch that switches the signal input of the first axle pressure regulator between the connection of the first electronic control unit and the second electronic control unit to the first axle pressure regulator. In this case, it can be determined which control unit is responsible for controlling the first axle.

[0034] The vehicle according to the application comprises the above-mentioned parking brake system. BRIEF DESCRIPTION OF DRAWINGS

[0035] Embodiments of the application are described below with reference to the accompanying drawings.

[0036] Figure 1 The architecture of the brake system according to a first embodiment of the application is shown.

[0037] Figure 2 The architecture of the brake system according to a second embodiment of the application is shown. DETAILED DESCRIPTION

[0038] Figure 1 The brake system B is shown, which comprises a plurality of components. In general, there is a first electronic control unit 3 and a second electronic control unit 18, which are integrated together with the parking brake unit 15 into an air supply unit 4. From the air supply unit 4, a pneumatic connection is led to a first axle pressure regulator 9, for example for the front axle, to a second axle pressure regulator 10, for example for the rear axle, and to a trailer module 8. The front axle pressure regulator 9 is pneumatically connected to a service brake chamber 12, for example for the front axle, between which a pressure control valve 11 is provided, which serves as an ABS valve. The second pressure regulator 10 is pneumatically connected to a spring cylinder 13, which is usually provided in the rear axle. Furthermore, the parking brake unit 15 integrated in the air supply unit 4 is provided with a direct pneumatic line between the trailer control module 8 and the spring brake cylinder 13. The first electronic control unit 3 is electrically connected to a first power supply unit 1 and the second electronic control unit 18 is electrically connected to a second power supply unit 2. Furthermore, the first electronic control unit 3 and the second electronic control unit 18 are electrically connected to a foot brake module 5, which is suitable for actuating the service brake function. Furthermore, the second electronic control unit 18 has an electrical connection to a hand brake module 6, which is suitable for actuating the parking brake function.

[0039] Furthermore, a third electronic control unit 14, which is suitable for executing highly autonomous driving applications, is provided with an electrical connection between the first electronic control unit 3 and the second electronic control unit 18. Furthermore, the first electronic control unit 3 is provided with an analogue and digital electrical connection to the front axle pressure regulator 9 and also to the second axle pressure regulator 10. The first electronic control unit 3 is also provided with an (only analogue) electrical connection to the pressure control valve 11. The second electronic control unit 18 is also provided with an analogue and digital connection to the front axle pressure regulator 9. The digital connection of the first electronic control unit 3 and the second electronic control unit 18 to the front axle pressure regulator 9 is directly connected to the front axle pressure regulator, whereas between the analogue lines of the first electronic control unit 3 and the second electronic control unit 18 a first electronic switch 7 is provided. Here, the input to the front axle pressure regulator 9 can be switched. There are also a first external signal source 16 and a second external signal source 17, both of which are digitally connected to the first electronic control unit 3 and the second electronic control unit 18. This architecture enables a redundant design, which can cope with faults.

[0040] When the brake system B is intact, the service brake function is controlled by the first electronic control unit 3 as the main unit. The brake demand can come from the first external source 16 or the foot brake module 5. In the event of a fault in the first electronic control unit 3 or the first power supply 1, the brake control is taken over by the second electronic control unit 18, the spring brake cylinder 13 of the rear axle is actuated by the proportional parking brake control, and the first axle regulator 9 is electronically controlled and powered by the second electronic control unit 18. If the second electronic control unit 18, which normally executes the parking brake function, or its second power supply 2, has any fault, the first electronic control unit 3 also controls the parking system, in which case the parking brake is temporarily simulated by the service brake actuation (first axle pressure regulator 9 and service brake chamber 12).

[0041] Furthermore, a first trailer communication line 22, a second trailer communication line 23 and a third trailer communication line 24 are provided for communication with the trailer. There is also a second electronic switch 19 for switching between the first electronic control unit 3 and the second electronic control unit 18, which are connected to the first trailer communication line 22. The second trailer communication line 23 is connected to the first electronic control unit 3 and the third trailer communication line 24 is connected to the second electronic control unit 18.

[0042] Figure 2A slightly different scheme is shown, in which most of the functions are the same. The difference is that the parking brake unit 15 is not integrated into the air supply system 4, but is provided as a separate unit. Regarding commands, it is not directly connected to the second electronic control unit 18, but indirectly: the second electronic control unit can send braking commands to the second external signal source 17, and the third electronic signal source 21 can send braking commands to the parking brake unit 15 again. Parking brake demand can be pneumatically forwarded from the parking brake module 15 to the trailer control module 8. The parking brake unit 15 is also pneumatically connected to the trailer module 8 and the spring cylinder 13. It is also supplied with air by the air supply system 4. The braking command comes directly from the handbrake module 6, which is no longer connected to the first electronic control unit 3 and the second electronic control unit 18. The parking brake module 15 has a third power source 20 and a third external source 18, through which the parking brake module 15 can be directly controlled. Now there is also redundancy between the first electronic control unit 3 and the second electronic control unit 18, but the parking brake module 15 is a third control module and can also undertake any other control functions.

[0043] The invention described above is not limited to the embodiments described above. More axles may need to be controlled, and the air supply unit 4 may also have an additional power supply system.

[0044] List of reference numerals

[0045] 1 First power supply unit

[0046] 2 Second power supply unit

[0047] 3. First Electronic Control Unit (Electronic Service Brake)

[0048] 4. Air supply unit

[0049] 5. Foot brake module (service brake)

[0050] 6. Handbrake module (parking brake)

[0051] 7 First Electronic Switch

[0052] 8 Trailer Control Module

[0053] 9. Front axle pressure regulator

[0054] 10 Rear Axle Pressure Regulator

[0055] 11. Pressure control valve (ABS valve)

[0056] 12 Service Brake Chamber

[0057] 13 Spring brake cylinder

[0058] 14. Third Electronic Control Unit (Highly Automated Driving)

[0059] 15 Parking brake unit

[0060] 16. First external signal source (braking demand)

[0061] 17 Second external signal source

[0062] 18. Second Electronic Control Unit (Parking Brake)

[0063] 19 Second Electronic Switch

[0064] 20 Third power supply unit (parking brake)

[0065] 21. Third external signal source (parking brake unit)

[0066] 22 First trailer communication line

[0067] 23 Second trailer communication line

[0068] 24 Third trailer communication line

Claims

1. A brake system (B) for a vehicle, wherein The brake system comprises: a first electronic control unit (3) suitable, inter alia, for controlling service brake functions; a second electronic control unit (18) suitable, inter alia, for controlling parking brake functions; a first axle pressure regulator (9) pneumatically connected to at least one service brake chamber (12) associated with a first axle of the vehicle; a second axle pressure regulator (10) pneumatically connected to at least one spring brake cylinder (13) associated with a second axle of the vehicle; a parking brake unit (15) also pneumatically connected to the spring brake cylinder (13) associated with the second axle of the vehicle; an air supply unit (14), wherein said air supply unit (14) is pneumatically connected to said first axle pressure regulator (9) and to said second axle pressure regulator (10); wherein said first control unit (3) is electrically connected to said first axle pressure regulator (9) and to said second axle pressure regulator (10), said second control unit (18) is electrically connected to said first axle pressure regulator (9), wherein said first electronic control unit (3) and said second electronic control unit (18) are integrated in said air supply unit (4).

2. The brake system (B) according to claim 1, wherein said parking brake unit (15) is also integrated in said air supply unit (4), and / or said parking brake unit (15) is controllable by means of an external signal source (21).

3. The brake system (B) according to any one of the preceding claims, wherein, said first electronic control unit (3) is also suitable for controlling parking brake functions, said second electronic control unit (18) is also suitable for controlling service brake functions.

4. The brake system (B) according to any one of the preceding claims, wherein, between said first axle pressure regulator (9) and said at least one service brake chamber (12) there is a pressure control valve (11) electrically connected to said first electronic control unit (3).

5. The braking system (B) according to any one of the preceding claims, wherein, The brake system also comprises a trailer control module (8) pneumatically connected to said air supply unit (4) and electrically connected to said first electronic control unit (3).

6. The brake system (B) according to any one of the preceding claims, wherein, The brake system also comprises a first power supply unit (1) connected to said first electronic control unit (3) and a second power supply unit (2) connected to said second electronic control unit (18).

7. The brake system (B) according to any one of the preceding claims, wherein, The brake system also comprises a foot brake module (5) suitable for service brake actuation, connected to said first electronic control unit (3) and to said second electronic control unit (18).

8. The brake system (B) according to any one of the preceding claims, wherein, The brake system also comprises a hand brake module (6) suitable for parking brake actuation, connected to said second electronic control unit (18).

9. The brake system (B) according to any one of claims 1, 3 to 7, wherein, The parking brake unit (15) is a separate unit which also acts as an additional control unit, optionally connected to a third power source (20), the brake system (B) also comprising a hand brake module (6) for parking brake actuation, connected to said parking brake unit (15).

10. The brake system (B) according to any one of the preceding claims, wherein, Analog and digital electrical connections are provided between the first control unit (3) and the first axle pressure regulator (9), between the first control unit (3) and the second axle pressure regulator (10) and between the second control unit (18) and the first axle pressure regulator (9).

11. The brake system (B) according to any one of the preceding claims, wherein The braking system further comprises a third electronic control unit (14) adapted to provide highly automated driving braking demands and connected to the first electronic control unit (3) and to the second electronic control unit (18).

12. The brake system (B) according to any one of the preceding claims, wherein, The first electronic control unit (3) and the second electronic control unit (18) are adapted to perform any type of vehicle control function.

13. The brake system (B) according to any one of the preceding claims, wherein, The first electronic control unit (3) and the second electronic control unit (18) are adapted to receive braking demands from any external source (16, 17, 20).

14. The brake system (B) according to any one of the preceding claims, wherein, The braking system further comprises a first electronic switch (7) switching the signal input of the first axle pressure regulator (9) between the connection of the first electronic control unit (3) and the second electronic control unit (18) and the first axle pressure regulator (9).

15. A vehicle comprising a braking system (B) according to any one of claims 1 to 14.

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