METHOD FOR OPERATING A BRAKE SYSTEM OF A MOTOR VEHICLE, COMPUTER PROGRAM PRODUCT, CONTROL UNIT AND BRAKE SYSTEM

Abstract

A method for operating a brake system of a motor vehicle, wherein the brake system has a brake pedal, which can be actuated by a driver of the motor vehicle, a brake booster, which can be coupled or is coupled to the brake pedal, a brake cylinder, such as a brake master cylinder, which can be coupled or is coupled to the brake booster and can be supplied with hydraulic fluid, and a hydraulic arrangement, which acts between the brake cylinder and at least one wheel brake, wherein the method comprises at least the step of: decoupling the brake pedal from the at least one wheel brake by the hydraulic arrangement, and a computer program, control unit or system having a plurality of control units and brake system.

Claims

1. A method for operating a brake system of a motor vehicle, wherein the brake system has a brake pedal, which can be actuated by a driver of the motor vehicle, a brake booster, which can be coupled or is coupled to the brake pedal, a brake cylinder, which can be coupled or is coupled to the brake booster and can be supplied with hydraulic fluid, and a hydraulic arrangement, which acts between the brake cylinder and at least one wheel brake, wherein the method comprises at least the step of: decoupling of the brake pedal from the at least one wheel brake the hydraulic arrangement.

2. The method according to claim 1, wherein the decoupling is carried out at least temporarily and/or the decoupling is carried out during an autonomous or partially autonomous driving mode.

3. The method according to claim 1, wherein the hydraulic arrangement is activated in such a way that the brake pedal is decoupled from the at least one wheel brake at least temporarily and/or during an autonomous or partially autonomous driving mode.

4. The method according to claim 1, wherein the hydraulic arrangement has a valve arrangement which is activated in order to decouple the brake pedal from the at least one wheel brake.

5. The method according to claim 1, wherein the hydraulic arrangement has at least one brake circuit, wherein the at least one brake circuit comprises at least one first shut-off valve for hydraulically separating the at least one wheel brake and/or the at least one brake circuit from the brake cylinder, at least one second shut-off valve, which is assigned to the at least one wheel brake, for hydraulically separating the at least one wheel brake from the brake cylinder and/or from an outlet side of a pump, and at least one third shut-off valve, which is arranged in the return line of the at least one wheel brake, wherein the at least one first shut-off valve, the at least one second shut-off valve and the at least one third shut-off valve are activated in such a way as to open them.

6. The method according to claim 5, wherein the at least one brake circuit comprises a fluid accumulator, which is connected on the inlet side to the pump, such as a hydraulic pump, and/or is connected to the return line of the at least one wheel brake, to the outlet side of the at least one third shut-off valve, wherein hydraulic fluid is stored, in the fluid accumulator when the at least one first, second and third shut-off valve are open.

7. The method according to claim 6, wherein the fluid accumulator is activated, wherein hydraulic fluid is fed back in such a way that the brake pedal is moved and/or pushed back by a pedal travel which is opposite to the actuating travel of the brake pedal.

8. The method according to claim 5, wherein the pump is activated, with the result that the brake pedal is moved and/or pushed back by a pedal travel which is opposite to the actuating travel of the brake pedal.

9. The method according to claim 5, wherein the at least one second shut-off valve is activated in such a way as to close it, with the result that the at least one wheel brake is separated from the brake cylinder and/or from the outlet side of the pump.

10. The method according to claim 5, wherein at least one third shut-off valve is activated in such a way as to close it, with a result that the at least one second shut-off valve is isolated.

11. The method according to claim 1, wherein the hydraulic arrangement has a reservoir, which is connected to the at least one brake circuit in such a way that the brake pedal is decoupled, from the at least one wheel brake.

12. The method according to claim 1, wherein movement and/or pushing back of the brake pedal by a pedal travel, a haptic feedback message for the driver is generated.

13. The method according to claim 1, wherein the brake booster has a motor, wherein the brake booster and/or the motor of the brake booster are/is activated in such a way that the brake booster does not exert or cannot exert any force, such as servo force, on the brake cylinder.

14. The method according to claim 1, wherein the brake system has a generator device, and/or is coupled to the generator, wherein the generator device is activated in such a way that no generator torque is generated or can be generated.

15. A computer program comprising a program code for carrying out a method according to claim 1, when the computer program product is executed on a processor.

16. A control unit or system comprising a plurality of control units for a motor vehicle, comprising at least one processor and the computer program according to claim 15.

17. A brake system for a motor vehicle, wherein the brake system is designed and/or configured to carry out the method according to claim 1.

18. The method according to claim 6, wherein the pump is activated, with the result that the brake pedal is moved and/or pushed back by a pedal travel which is opposite to the actuating travel of the brake pedal.

19. The method according to claim 7, wherein the at least one second shut-off valve is activated in such a way as to close it, with the result that the at least one wheel brake is separated from the brake cylinder and/or from the outlet side of the pump.

20. The method according to claim 9, wherein at least one third shut-off valve is activated in such a way as to close it, with a result that the at least one second shut-off valve is isolated.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0035] FIG. 1 shows a brake system with a hydraulic arrangement in a first exemplary configuration; and

[0036] FIG. 2 shows the brake system according to FIG. 1 with the hydraulic arrangement in a second exemplary configuration.

DETAILED DESCRIPTION

[0037] FIG. 1 shows schematically a brake system 1 with a hydraulic arrangement 2, such as an ESC hybrid, in a first configuration (state of valves).

[0038] The brake system 1 has a brake pedal, which can be actuated by a driver of the motor vehicle, a brake booster 3, which can be coupled or is coupled to the brake pedal, and a brake cylinder, such as a brake master cylinder, which can be coupled or is coupled to the brake booster 3 and can be supplied with hydraulic fluid. The hydraulic arrangement 2 acts between the brake cylinder and the at least one wheel brake 4. The hydraulic arrangement 2 is connected, on the one hand, to the brake cylinder, for example by fluid technology, such as a fluid line, and, on the other hand, to the at least one wheel brake 4, for example by a fluid line. The hydraulic arrangement 2 illustrated in FIG. 1 has a brake circuit, such as a braking circuit, which is connected to two wheel brakes 4 (VR, HL). The hydraulic arrangement 2 can also have a further, second brake circuit, which in turn is connected to two wheel brakes 4.

[0039] A method for operating the brake system, for example carried out by the brake system 1, comprises the step of decoupling, such as hydraulic decoupling, of the brake pedal from the at least one wheel brake 4 by the hydraulic arrangement 2. Decoupling can take place at least temporarily and/or during an autonomous or partially autonomous driving mode. The hydraulic arrangement 2 can be activated in such a way that the brake pedal is decoupled from the at least one wheel brake 4 at least temporarily and/or during the autonomous or partially autonomous driving mode.

[0040] The hydraulic valve arrangement 2 has a valve arrangement 5, which can be activated in order to decouple the brake pedal from the at least one wheel brake 4. The at least one brake circuit of the hydraulic arrangement 2 has at least one first shut-off valve 6 (TC_ISO) for hydraulically separating the at least one wheel brake 4 and/or the at least one brake circuit from the brake cylinder. Furthermore, the at least one brake circuit of the hydraulic arrangement 2 has at least one second shut-off valve 7 (ABS_NO, ABS_ISO), which is assigned to the at least one wheel brake 4, for hydraulically separating the at least one wheel brake 4 from the brake cylinder and/or from an outlet side of a pump 8, such as a hydraulic pump 8. Furthermore, the at least one brake circuit of the hydraulic arrangement 2 has at least one third shut-off valve 10 (ABS_NC, dump), which is arranged in the return line 9 of the at least one wheel brake 4.

[0041] The at least one first shut-off valve 2, the at least one second shut-off valve 7 and the at least one third shut-off valve 10 are activated in such a way as to open these.

[0042] The at least one brake circuit of the hydraulic arrangement 2 has a fluid accumulator 11, such as a volume accumulator and/or pressure accumulator and/or low-pressure accumulator, which is connected on the inlet side to the hydraulic pump 8 and is connected to the return line 9 of the at least one wheel brake 4, to the outlet side of the at least one third shut-off valve 10. When at least one first, second and third shut-off valve 6, 7, 10 is open, hydraulic fluid can flow into the fluid accumulator 11 and be stored, in one exemplary arrangement, temporarily stored, in the fluid accumulator 11.

[0043] When the fluid accumulator 11 is activated, e.g. opened, hydraulic fluid is fed back in such a way that the brake pedal is moved and pushed back by a pedal travel which is opposite to the actuating travel of the brake pedal. In addition, or as an alternative, the hydraulic pump 8 can be activated, with the result that the brake pedal is moved and pushed back by a pedal travel which is opposite to the actuating travel of the brake pedal. The at least one second shut-off valve 7 can additionally or alternatively be activated in such a way in order to close the latter that the at least one wheel brake 4 is separated from the brake cylinder and/or from the outlet side of the hydraulic pump 8. In addition, or as an alternative, the hydraulic arrangement 2 can have a reservoir, such as a fluid reservoir, which is connected to the at least one brake circuit of the hydraulic arrangement 2 in such a way that the brake pedal is decoupled, for example hydraulically, from the at least one wheel brake 4.

[0044] The brake system 1 is designed and/or configured to carry out the method described above and/or below.

[0045] By operation of the brake pedal, for example by the movement and/or pushing back of the brake pedal by a pedal travel, a haptic feedback message for the driver can be generated.

[0046] The brake booster 3 has a motor, such as a servo motor, wherein the brake booster 3 and/or the motor of the brake booster 3 are/is activated in such a way that the brake booster 3 does not exert or cannot exert any force, such as servo force, on the brake cylinder. The force, such as servo force, can have the value zero (F=0). The brake system 1 is furthermore coupled to a generator device 12, for regenerative braking, wherein the generator device 12 is activated in such a way that no generator torque (M=0) is generated or can be generated.

[0047] FIG. 2 shows the brake system 1 according to FIG. 1 with the hydraulic arrangement 2 in a second configuration (state of the valves).

[0048] In contrast to the configuration of the hydraulic arrangement 2 illustrated in FIG. 1, the at least one third shut-off valve 10 (ABS_NC, dump) in the configuration illustrated according to FIG. 2 is activated in such a way as to close it, with the result that the at least one second shut-off valve 7 (ABS_NO, ABS_ISO) is isolated. It is thereby possible to produce a greater pedal travel, for example greater than 80 mm.

[0049] In other respects, attention is additionally drawn, to FIG. 1 and the associated description.

[0050] In particular, “can” denotes optional features of the disclosure. Accordingly, there are also developments and/or exemplary arrangements of the disclosure which additionally or alternatively have the respective feature or features.

[0051] If necessary, it is also possible to select isolated features from the combinations of features disclosed here and, while breaking up a structural and/or functional relationship which may exist between the features, to use them in combination with other features to define the subject matter of a claim. The sequence and/or number of steps of the method can be varied.