DE-102012222718-B4 - Control device for a vehicle's braking system and method for operating a vehicle's braking system

DE102012222718B4DE 102012222718 B4DE102012222718 B4DE 102012222718B4DE-102012222718-B4

Abstract

Control device (10) for a braking system of a vehicle with: a control device (12) by means of which, at least taking into account a preset signal (22) with regard to a target vehicle deceleration (a) that can be specified by a driver by means of an actuation of a brake actuation element (11) of the vehicle and/or by a cruise control system of the vehicle, a first target brake pressure to be set in at least one first wheel brake cylinder (14) of a first brake circuit (16) of the brake system and a second target brake pressure to be set in at least one second wheel brake cylinder (18) of a second brake circuit (20) of the brake system can be determined, wherein at least one component (24, 26, 28) of the brake system can be controlled by means of the control device (12), so that a first actual brake pressure present in at least the first wheel brake cylinder (14) of the first brake circuit (16) taking into account the specified first target brake pressure and a second actual brake pressure present in at least the second wheel brake cylinder (18) of the second brake circuit (20) can be determined, wherein at least one component (24, 26, 28) of the brake system can be controlled by means of the control device (12), so that a first actual brake pressure present in at least the first wheel brake cylinder (14) of the first brake circuit (16) taking into account the specified first target brake pressure and a second actual brake pressure present in at least the second wheel brake cylinder (18) of the second brake circuit (20) can be determined The actual brake pressure can be varied taking into account the specified second target brake pressure; characterized by the fact that the first actual brake pressure can be reduced according to the specified first target brake pressure and the second actual brake pressure can be reduced according to the specified second target brake pressure, wherein the control device (12) is designed to output at least one first control signal (30) to a master brake cylinder pressure variability device (24), which can be controlled by means of the at least one first control signal (30) such that the master brake cylinder pressure (pHZ) in a master brake cylinder (32) of the brake system can be adjusted to be less than or equal to a minimum of the first target brake pressure and the second target brake pressure, and to output at least one second control signal (36) to a first switching valve (26) of the first brake circuit (16) and/or to a second switching valve (26) of the second brake circuit (20), wherein the first switching valve (26) is between the the master brake cylinder (32) and at least one first wheel inlet valve (28) associated with at least one first wheel brake cylinder (14), and the second changeover valve (26) is arranged between the master brake cylinder (32) and at least one second wheel inlet valve (28) associated with at least one second wheel brake cylinder (18), and wherein the first changeover valve (26) and the second changeover valve (26) can be controlled by means of the at least one second control signal (36) such that the first actual brake pressure and/or the second actual brake pressure can be additionally reduced; and The first actual brake pressure can be increased according to the specified first target brake pressure, and the second actual brake pressure can be increased according to the specified second target brake pressure, wherein the control device (12) is designed to output at least one third control signal (38) to the master brake cylinder pressure variability device (24), which can be controlled by means of the at least one third control signal (38) such that the master brake cylinder pressure (pHZ) can be set to a maximum of the first target brake pressure and the second target brake pressure, and to output at least one fourth control signal (40) to the at least one first wheel inlet valve (28) of the first brake circuit (16) and/or to the at least one second wheel inlet valve (28) of the second brake circuit (20), which can each be controlled by means of the at least one fourth control signal (40) such that the first actual brake pressure and/or the second actual brake pressure can be further increased. are.

Inventors

Christoph Betz
Olaf Grotheer
Michael Bunk
Christian Koehler
Michael Reichert

Assignees

ROBERT BOSCH GMBH

Dates

Publication Date: 20260513
Application Date: 20121211

Claims (12)

Control device (10) for a vehicle braking system comprising: a control unit (12) by means of which, at least taking into account a preset signal (22) with regard to a target vehicle deceleration (a) that can be specified by a driver by means of an actuation of a brake actuation element (11) of the vehicle and/or by a cruise control system of the vehicle, a first target brake pressure to be set in at least one first wheel brake cylinder (14) of a first brake circuit (16) of the braking system and a second target brake pressure to be set in at least one second wheel brake cylinder (18) of a second brake circuit (20) of the braking system can be determined, wherein at least one component (24, 26, 28) of the braking system can be controlled by means of the control unit (12), so that a first actual brake pressure present in at least the first wheel brake cylinder (14) of the first brake circuit (16) taking into account the specified first target brake pressure and a second actual brake pressure present in at least the second wheel brake cylinder (18) of the second brake circuit (20) the existing second actual brake pressure can be varied taking into account the specified second target brake pressure; characterized in that the first actual brake pressure can be reduced according to the specified first target brake pressure and the second actual brake pressure can be reduced according to the specified second target brake pressure, wherein the control device (12) is designed to output at least one first control signal (30) to a master brake cylinder pressure variability device (24), which can be controlled by means of the at least one first control signal (30) such that the master brake cylinder pressure (pHZ) in a master brake cylinder (32) of the brake system can be adjusted to be less than or equal to a minimum of the first target brake pressure and the second target brake pressure, and to output at least one second control signal (36) to a first switching valve (26) of the first brake circuit (16) and/or to a second switching valve (26) of the second brake circuit (20), wherein the first switching valve (26) is located between the master brake cylinder (32) and at least one of the at least one first wheel brake cylinder (14). the first wheel inlet valve (28) is arranged and the second changeover valve (26) is arranged between the master brake cylinder (32) and at least one second wheel inlet valve (28) associated with at least one second wheel brake cylinder (18), and wherein the first changeover valve (26) and the second changeover valve (26) can be controlled by means of the at least one second control signal (36) in such a way that the first actual brake pressure and/or the second actual brake pressure can be additionally reduced; and the first actual brake pressure can be increased according to the specified first target brake pressure and the second actual brake pressure can be increased according to the specified second target brake pressure, wherein the control device (12) is designed to output at least one third control signal (38) to the master brake cylinder pressure variability device (24), which can be controlled by means of the at least one third control signal (38) such that the master brake cylinder pressure (pHZ) can be set to a maximum of the first target brake pressure and the second target brake pressure, and to output at least one fourth control signal (40) to the at least one first wheel inlet valve (28) of the first brake circuit (16) and/or to the at least one second wheel inlet valve (28) of the second brake circuit (20), which can each be controlled by means of the at least one fourth control signal (40) such that the first actual brake pressure and/or the second actual brake pressure can be further increased. are.
Control device (10) according Claim 1 , wherein the control device (12) is additionally designed to control a Δp control of the first actual brake pressure to be reduced by the first switching valve (26) and/or a Δp control of the second actual brake pressure to be reduced by the second switching valve (26) by means of the at least one second control signal (36).
Control device (10) according Claim 1 or 2 , wherein the control device (12) is additionally designed to control, by means of the at least one fourth control signal (40), a Δp control of the first actual brake pressure to be increased by means of the at least one first wheel inlet valve (28) and/or a Δp control of the second actual brake pressure to be increased by means of the at least one second wheel inlet valve (28).
Control device (10) according to one of the preceding claims, wherein the control device (12) is additionally designed to control at least one plunger (24) as a master brake cylinder pressure variability device (24) by means of the at least one first control signal (30) and/or the at least one third control signal (38).
Control device (10) according to one of the preceding claims, wherein the control device (12) is additionally designed to determine the first target brake pressure and/or the second target brake pressure, taking into account at least one generator braking torque that can be exerted on at least one axle assigned to the at least one first wheel brake cylinder (14) and/or the at least one second wheel brake cylinder (18) by means of at least one electric motor.
Control device (10) according to one of the preceding claims, wherein the control device (12) is additionally designed to determine a target value with respect to an amplifier force to be exerted on the brake actuating element (11) by means of a brake booster (42) taking into account the target signal (22), the first target brake pressure, the second target brake pressure, the determined or estimated first actual brake pressure and/or the determined or estimated second actual brake pressure, and to output a brake booster control signal (44) corresponding to the target value to the brake booster (42).
Braking system for a vehicle with a control device (10) according to one of the preceding claims.
Method for operating a vehicle braking system comprising the steps of: determining a first target braking pressure to be set in at least one first wheel brake cylinder (14) of a first brake circuit (16) of the braking system and a second target braking pressure to be set in at least one second wheel brake cylinder (18) of a second brake circuit (20) of the braking system, taking into account at least one target value specified by a driver by means of an actuation of a brake actuation element (11) of the vehicle and/or by a cruise control system of the vehicle with regard to a target vehicle deceleration (a) to be exerted on the vehicle (S1); and varying a first actual braking pressure present in at least the first wheel brake cylinder (14) of the first brake circuit (16) taking into account the determined first target braking pressure and a second actual braking pressure present in at least the second wheel brake cylinder (18) of the second brake circuit (20) taking into account the determined second target braking pressure; characterized by : Reducing the first actual brake pressure according to the specified first target brake pressure and the second actual brake pressure according to the specified second target brake pressure by: - Setting a master brake cylinder pressure (pHZ) in a master brake cylinder (32) of the brake system less than or equal to a minimum of the first target brake pressure and the second target brake pressure (S2); and actuating a first switching valve (26) of the first brake circuit (16), which is arranged between the master brake cylinder (32) and at least one first wheel inlet valve (28) assigned to the at least one first wheel brake cylinder (14), to further reduce the first actual brake pressure and/or actuating a second switching valve (26) of the second brake circuit (20), which is arranged between the master brake cylinder (32) and at least one second wheel inlet valve (28) assigned to the at least one second wheel brake cylinder (18), to further reduce the second actual brake pressure (S3); and increasing the first actual brake pressure according to the specified first target brake pressure and the second actual brake pressure according to the specified second target brake pressure by: - setting the master brake cylinder pressure (pHZ) greater than or equal to a maximum of the first target brake pressure pressure and the second target brake pressure (S4); and - actuation of at least one first wheel inlet valve (28) of the first brake circuit (16) to further increase the first actual brake pressure and/or actuation of at least one second wheel inlet valve (28) of the second brake circuit (20) to further increase the second actual brake pressure (S5).
Procedure according to Claim 8 , wherein the first switching valve (26) is controlled to perform a Δp control of the first actual brake pressure to be reduced and/or the second switching valve (26) is controlled to perform a Δp control of the second actual brake pressure to be reduced.
Procedure according to Claim 8 or 9 , wherein the at least one first wheel inlet valve (28) is controlled for a Δp control of the first actual brake pressure to be increased and/or the at least one second wheel inlet valve (28) is controlled for a Δp control of the second actual brake pressure to be increased.
Procedure according to one of the Claims 8 until 10 , wherein the master brake cylinder pressure (pHZ) is reduced and/or increased by means of at least one plunger (24).
Procedure according to one of the Claims 8 until 11 , taking into account the target value, the first target brake pressure, the second target brake pressure, the determined or estimated first actual brake pressure and/or the determined or estimated second actual brake pressure, a target value is set with respect to an amplifier force to be exerted on the brake actuating element (11) by means of a brake booster (42) and the brake booster (42) is controlled accordingly (S6).

Description

The invention relates to a control device for a vehicle's braking system. The invention also relates to a vehicle's braking system. Furthermore, the invention relates to a method for operating a vehicle's braking system. State of the art In the DE 10 2010 040 854 A1 A hydraulic braking system and a method for its operation are described. By using the hydraulic braking system or by carrying out the method for its operation, it should be possible to brake a vehicle using at least one electric motor and a hydraulic braking system. Furthermore, the following also describe DE 10 2011 077 329 A1 , the WO 2011/ 104 056 A1 and the DE 10 2010 008 033 A1 Each control device and method for braking a vehicle using its at least one electric motor and a hydraulic braking system working in conjunction with it. Disclosure of the invention The invention provides a control device for a braking system of a vehicle with the features of claim 1, a braking system for a vehicle with the features of claim 7 and a method for operating a braking system of a vehicle with the features of claim 8. Advantages of the invention The present invention ensures high pressure point accuracy when setting the first actual brake pressure to/equal to the specified first target brake pressure and the second actual brake pressure to/equal to the specified second target brake pressure. Components of an ESP system of the brake system, which are typically already present in a conventional brake system, can be used for this purpose. Thus, existing components can be used to achieve the comfortable and precise pressure point setting made possible by the present invention. The present invention can therefore be implemented without any further development that would increase the manufacturing costs or the installation space required for the brake system. Furthermore, the present invention allows for axle-specific modulation of the actual brake pressures. At the same time, the present invention ensures that a desired distribution of braking torques between the front and rear axles can be reliably maintained. Thus, vehicle pitching induced by a disturbance in the desired distribution of braking torques, which the driver often perceives as bothersome, is reliably prevented. In an advantageous embodiment, the control device is additionally designed to control, by means of at least one second control signal, a Δp control of the first actual brake pressure to be reduced by the first switching valve and/or a Δp control of the second actual brake pressure to be reduced by the second switching valve. This allows for high accuracy when setting the desired first actual brake pressure and/or the desired second actual brake pressure by means of the resulting pressure reduction. By using so-called Δp control, the dependence of the set first actual brake pressure and/or second actual brake pressure on the volumetric capacity of the hydraulic brake system is also eliminated, at least to a first approximation. Alternatively or additionally, the control unit can also be designed to use at least one fourth control signal to control a Δp control of the first actual brake pressure to be increased by means of the at least one first wheel inlet valve and/or a Δp control of the second actual brake pressure to be increased by means of the at least one second wheel inlet valve. Thus, high accuracy can also be guaranteed for the pressure build-up carried out in this way. Preferably, the control device is additionally designed to actuate at least one plunger as a master brake cylinder pressure variability device by means of at least one first control signal and/or at least one third control signal. The desired master brake cylinder pressure can thus be set independently of the wheel inlet valves and the changeover valves. In addition, the plunger can be operated using a relatively simple control scheme, since it only needs to ensure a sufficiently large pressure differential, but not an exact pressure. Therefore, a comparatively inexpensive plunger, especially with inexpensive control electronics, can be used for the present invention. Preferably, the control device is additionally designed to set the first target brake pressure and/or the second target brake pressure, taking into account at least one generator braking torque that can be exerted on at least one axle assigned to the at least one first wheel brake cylinder and/or the at least one second wheel brake cylinder by means of at least one electric motor. The present invention thus also ensures a constant brake force distribution during recuperation. Due to the high pressure setting accuracy, deceleration fluctuations during recuperation can be minimized. The present invention can therefore also be used to encourage drivers to purchase a vehicle equipped with the at least one electric motor, which allows for more energy-efficient and lower-emission driving. In an advantageous further development, the control unit is additionall