ELECTROHYDRAULIC BRAKE CONTROL UNIT FOR A MOTOR VEHICLE AND BRAKE SYSTEM WITH SUCH A BRAKE CONTROL UNIT

Description

[0001] The invention relates to an electro-hydraulic brake control unit according to the preamble of claim 1 and to a brake system with such a brake control unit.

[0002] From DE 10 2017 216 617 A1, a brake control unit is known with four output connections for four hydraulically actuated wheel brakes, a first electronic control unit, a second electronic control unit, a hydraulic fluid reservoir, and an inlet and outlet valve for each output connection, wherein the respective output connection is connected to the hydraulic fluid reservoir via the outlet valve. To be suitable for highly automated driving and to eliminate the need for a mechanical and / or hydraulic fallback system in which the driver can actuate the wheel brakes manually, the brake control unit comprises a first and a second electrically controlled hydraulic pressure source, wherein the first pressure source is actuated by the first electronic control unit and the second pressure source by the second electronic control unit.Furthermore, an electrically operated circuit separation device is provided, by which the brake system is separated in the de-energized state into a first brake circuit with the first pressure source and two of the wheel brakes and a second brake circuit with the second pressure source and the two other wheel brakes.

[0003] Document DE 10 2013 224 870 A1 discloses a brake actuation unit for a "brake-by-wire" motor vehicle braking system with a brake pedal-operated master brake cylinder and an electrically controlled pressure supply device.

[0004] Document DE 10 2018 207 765 A1 discloses an electronic braking system.

[0005] The object of the present invention is to provide an alternative electro-hydraulic brake control unit and brake system suitable for highly automated driving for a motor vehicle, which can do without a mechanical and / or hydraulic fallback level and yet has high availability and thus offers sufficient safety for highly automated driving or an autopilot function.

[0006] This problem is solved according to the invention by an electro-hydraulic brake control unit according to claim 1 and a brake system according to claim 15.

[0007] The invention is based on the idea that the brake control unit comprises an electrically controllable hydraulic pressure source, an inlet and outlet valve for each of the at least four wheel brakes, a first electronic control and regulating unit and a second electronic control and regulating unit, wherein the pressure source is formed by a cylinder-piston arrangement with a pressure chamber, the piston of which can be moved forwards and backwards by an electromechanical actuator, wherein the pressure chamber is connected via a first electrically actuated pressure switching valve to a brake line section to which the at least four inlet valves are connected.Furthermore, electrical and / or electronic means are provided which are configured so that, in the event of a failure of the first electronic control unit, the electromechanical actuator is controlled by the second electronic control unit and builds up pressure to actuate the wheel brakes, and that, in the event of a failure of the second electronic control unit, the electromechanical actuator is controlled by the first electronic control unit and builds up pressure to actuate the wheel brakes.

[0008] The brake line section connects the output port of the first pressure-sensing valve to each of the input ports of the (at least four) inlet valves. The brake line section preferably connects the at least four inlet valves directly to each other, i.e., the inlet valves of the first and second output ports. In this sense, the brake control unit, or rather its pressure supply via the hydraulic pressure source, is preferably designed as a single-circuit system.

[0009] Preferably, no valve is arranged in the brake line section, e.g., no electrically or hydraulically actuated valve and no check valve. The brake line section is preferably delimited on the wheel brake side by the (at least four) inlet valves and on the pressure source side by the first pressure switching valve or, if a second pressure switching valve is present, by the first and the second pressure switching valves. If the brake line section is connected to the hydraulic fluid reservoir via a shut-off valve, the brake line section is delimited on the hydraulic fluid reservoir side by the shut-off valve.

[0010] In the event of a failure of one of the electronic control units, the electromechanical actuator is controlled by the other electronic control unit, and pressure is built up to actuate the wheel brakes in brake-by-wire mode for service braking.

[0011] A functioning electronic control unit enables the electromechanical actuator to be operated with at least part of its power to build up pressure for actuating the wheel brakes.

[0012] According to a preferred embodiment of the brake control unit according to the invention, the electrical and / or electronic means comprise an electromechanical actuator comprising a double-wound electric motor with a first motor winding and a second motor winding, wherein the first motor winding is, particularly preferably exclusively, controlled by the first electronic control unit and the second motor winding is, particularly preferably exclusively, controlled by the second electronic control unit. This eliminates the need for a second electrically controlled hydraulic pressure source. Even after a single electrical or electronic fault, it is possible to brake all wheel brakes.

[0013] Preferably, the electro-hydraulic brake control unit comprises at least two first output ports and two second output ports for at least four hydraulically actuated wheel brakes, an electrically controlled hydraulic pressure source, a first electronic control unit, a second electronic control unit, a pressure medium reservoir, in particular at atmospheric pressure, an inlet valve for each first and second output port, and an outlet valve for each first and second output port, through which the respective output port is connected to the pressure medium reservoir, wherein the pressure source is formed by a cylinder-piston arrangement with a pressure chamber and a piston, wherein the piston can be moved forwards and backwards by an electromechanical actuator, and wherein the pressure chamber is connected to a brake line section via a first electrically actuated pressure switching valve.to which the inlet valves are connected, and wherein the electromechanical actuator comprises a double-wound electric motor with a first motor winding and a second motor winding, the first motor winding being controlled by the first electronic control unit and the second motor winding by the second electronic control unit. The double-wound electric motor, with the first motor winding being controlled by the first electronic control unit and the second motor winding being controlled by the second electronic control unit, constitutes electrical and / or electronic means configured such that, in the event of a failure of the first electronic control unit, the electromechanical actuator is controlled by the second electronic control unit and builds up pressure to actuate the wheel brakes.and that in the event of a failure of the second electronic control unit, the electromechanical actuator is controlled by the first electronic control unit and builds up pressure to actuate the wheel brakes.

[0014] The double-wound electric motor thus comprises a first motor winding and a second motor winding, with each winding being controlled by one of the two electronic control units. In a sense, the electric motor is a two-part system. When both motor windings are controlled by both electronic control units, the electric motor delivers full power. If only one of the two electronic control units controls the corresponding motor winding, the pressure source can build up pressure, albeit at a reduced level and with reduced dynamics, and this pressure is used to apply pressure to at least all four wheel brakes. The vehicle can still be braked and brought to a standstill.

[0015] Particularly preferably, the first electronic control unit comprises a first output stage for providing phase voltages and a first driver stage for controlling the first output stage, wherein the first output stage is connected to the first motor winding, and the second electronic control unit comprises a second output stage for providing phase voltages and a second driver stage for controlling the second output stage, wherein the second output stage is connected to the second motor winding.

[0016] Advantageously, the first and second electronic control units each include a motor processor.

[0017] Advantageously, the first electronic control unit is supplied by a first electrical power supply, and the second electronic control unit is supplied by a second electrical power supply that is independent of the first power supply.

[0018] According to another preferred embodiment of the brake control unit according to the invention, the electrical and / or electronic means comprise an electromechanical actuator comprising a single-wound electric motor with one motor winding, and the first and second electronic control units each comprising a power stage for providing phase voltages and a driver stage for controlling the power stage. The power stage of the first electronic control unit and the power stage of the second electronic control unit are connected to the motor winding of a single-wound electric motor and are designed such that their outputs are high-impedance in the event of a failure of the associated electronic control unit. This allows the motor winding of the electric motor to be controlled by either of the two electronic control units.

[0019] Preferably, the first and second electronic control and regulation units each include a motor processor.

[0020] It is particularly preferred that the first electronic control unit is supplied by a first electrical power supply and the second electronic control unit is supplied by a second electrical power supply, independent of the first power supply.

[0021] According to a further preferred embodiment of the brake control device according to the invention, the electrical and / or electronic means comprise that the electromechanical actuator includes a single-wound electric motor with one motor winding, that the first and the second electronic control unit each comprise a motor processor, that a third electronic control unit is provided which comprises a first and a second output stage for providing phase voltages, a first and a second driver stage and relays, wherein the relays are designed such that each motor processor can transmit its output signals to each of the two driver stages and each driver stage can control each output stage, and that the first and the second output stage are connected to the motor winding of the single-wound electric motor.

[0022] Preferably, the first electronic control unit is supplied by a first electrical power supply, the second electronic control unit is supplied by a second electrical power supply independent of the first power supply, and the third electronic control unit can be switched between the first and the second power supply.

[0023] According to a further preferred embodiment of the brake control device according to the invention, the electrical and / or electronic means comprise that the electromechanical actuator includes a first and a second electric motor, each with a motor winding, wherein the first and the second electric motor can move the piston of the pressure source forward and backward, either alone or together; that the first electronic control unit comprises a first output stage for providing phase voltages and a first driver stage for controlling the first output stage, wherein the first output stage is connected to the motor winding of the first electric motor; and that the second electronic control unit comprises a second output stage for providing phase voltages and a second driver stage for controlling the second output stage, wherein the second output stage is connected to the motor winding of the second electric motor.

[0024] Preferably, the first and second electronic control and regulation units each include a motor processor.

[0025] The first electronic control unit is preferably supplied by a first electrical power supply, and the second electronic control unit is supplied by a second electrical power supply that is independent of the first power supply.

[0026] Preferably, the pressure switching valve and at least the inlet and outlet valves for two of the wheel brakes are actuated by the first electronic control unit. Particularly preferably, the first pressure switching valve and at least the inlet and outlet valves of the first output ports are actuated by the first electronic control unit.

[0027] The first electronic control unit and the second electronic control unit are preferably designed separately and connected to each other via redundant signal lines.

[0028] The first electronic control unit and the second electronic control unit are preferably electrically independent of each other in the sense that a failure of the first electronic control unit does not cause a failure of the second electronic control unit and vice versa.

[0029] Preferably, the pressure source is designed as a single circle. Particularly preferably, the pressure source comprises only one pressure chamber.

[0030] The pressure chamber is connected to the brake line section, to which the inlet valves are connected, via a first electrically actuated pressure control valve. Preferably, each inlet valve is connected to the first pressure control valve without the interposition of a further electrically actuated valve. Particularly preferably, each inlet valve is connected directly to the first pressure control valve, i.e., without the interposition of a valve.

[0031] In other words, preferably no electrically actuated valve, and more preferably no valve at all, is arranged in the brake line section between the first electrically actuated pressure switching valve and each of the inlet valves.

[0032] Preferably, each valve of the brake control unit, e.g. the inlet valves and / or the outlet valves and / or the pressure switching valve(s) and / or the isolating valve(s), is actuated by only or exclusively one of the two electronic control units.

[0033] Preferably, the first motor winding is controlled exclusively by the first electronic control unit and the second motor winding is controlled exclusively by the second electronic control unit.

[0034] According to a further development of the invention, electrically actuated parking brakes are provided on the wheels associated with the wheel brakes of the second output connections.

[0035] Preferably, the electrically operated parking brakes are actuated by the first electronic control unit so that, in the event of failure of the second control unit, the corresponding wheel brakes, advantageously those of the rear wheels, can be braked purely electrically and dynamically.

[0036] Preferably, each inlet valve is controllable via an analog control and is normally open. Particularly preferably, a check valve closing in the direction of the associated outlet port is connected in parallel to each inlet valve.

[0037] Preferably, each of the outlet valves is designed to be normally closed (closed when de-energized). The outlet valves are particularly preferably designed as switching valves.

[0038] Preferably, the first pressure switching valve and at least the inlet and outlet valves of the first output ports are actuated solely or exclusively by the first electronic control unit.

[0039] Preferably, the first output connections are assigned to the wheel brakes of one axle of the vehicle and the second output connections to the wheel brakes of the other axle of the vehicle. Particularly preferably, the first output connections are assigned to the wheel brakes of the front axle and the second output connections to the wheel brakes of the rear axle of the vehicle.

[0040] Preferably, for pressure control by the first control and regulating unit, a first pressure sensor is connected to the brake line section, wherein the signals of the first pressure sensor are supplied to the first electronic control and regulating unit and evaluated by it.

[0041] Preferably, a second pressure sensor is connected to the brake line section, with the signals from the second pressure sensor being fed to and evaluated by the second electronic control unit. This allows for precise pressure control by the second electronic control unit as well.

[0042] Preferably, the first electrically actuated pressure-switching valve is designed to be normally closed (NC), and the pressure chamber is additionally connected to the brake line section via a second electrically actuated, normally closed (NC) pressure-switching valve, which is actuated, in particular exclusively, by the second electronic control unit. The pressure chamber is thus hydraulically connected to the brake line section via a parallel connection of the first and second normally closed (NC) pressure-switching valves. Each of the two control units can connect the pressure chamber to the brake line section and vice versa.

[0043] Alternatively, it is preferred that the first electrically actuated pressure-switching valve is normally open. Advantageously, and particularly preferably exclusively, the first pressure-switching valve is actuated by the first electronic control unit. To increase the flow rate, the pressure chamber is particularly preferably connected to the brake line section via a check valve opening towards the inlet valves. In other words, a check valve opening towards the inlet valves or outlet ports is particularly preferably connected in parallel to the first electrically actuated pressure-switching valve. The pressure chamber is thus hydraulically connected to the brake line section via a parallel connection of the first, normally open pressure-switching valve and the check valve. Only the first control unit can connect or disconnect the brake line section from the pressure chamber.

[0044] Preferably, the brake control unit does not include any further hydraulic pressure source, in particular no further electrically controllable hydraulic pressure source.

[0045] The inlet and outlet valves of the second output ports are preferably, and especially preferably exclusively, actuated by the first electronic control unit, wherein the brake line section is connected to the pressure medium reservoir via a separating valve device with at least one first electrically actuated separating valve, wherein the first separating valve is actuated, especially preferably exclusively, by the second electronic control unit.

[0046] Preferably, the first isolating valve is normally closed (closed), and the isolating valve assembly comprises only the first electrically actuated isolating valve. This allows pressure equalization outside of braking situations using only one valve. Particularly preferably, a check valve opening in the direction of the outlet port is connected in parallel to one of the outlet valves of the second output port to prevent a vacuum in the system when de-energized.

[0047] Alternatively, the isolation valve device preferably comprises the first electrically actuated isolation valve and a second electrically actuated isolation valve located upstream or downstream of it, wherein the second isolation valve is actuated by the first electronic control unit. The first and second isolation valves are normally open.

[0048] Preferably, the inlet and outlet valves of the second output ports are actuated, and particularly preferably exclusively, by the second electronic control unit. No hydraulic connection between the brake line section and the pressure reservoir is provided via a shut-off valve. In the event of a failure of one of the control units, wheel-specific pressure modulation at two of the wheel brakes remains possible. Therefore, a second pressure sensor is particularly preferably connected to the brake line section, with the signals from the second pressure sensor being fed to and evaluated by the second electronic control unit. A check valve opening towards the output port is particularly preferably connected in parallel to one of the outlet valves of the second output ports to prevent a vacuum in the system when de-energized.

[0049] According to a further development of the invention, the outlet valves of the second output ports are designed to be normally open. The outlet valves of the second output ports are (additionally) preferably designed to be controllable by analogy. The outlet valves of the first output ports are particularly preferably designed as switching valves and are normally open. In this case, no hydraulic connection between the brake line section and the pressure medium reservoir is provided via a separating valve device.

[0050] According to a preferred embodiment of the further development, the inlet valves of the second output ports are actuated, in particular exclusively, by the first electronic control unit, and the exhaust valves of the second output ports are actuated, in particular exclusively, by the second electronic control unit. Particularly preferably, electrically actuated parking brakes are provided on the wheels associated with the second output ports, which are actuated, in particular exclusively, by the first electronic control unit.

[0051] According to another preferred embodiment of the further development, for one second output port, the inlet valve is actuated, in particular exclusively, by the first electronic control unit and the outlet valve is actuated, in particular exclusively, by the second electronic control unit, wherein for the other second output port, the inlet valve is actuated, in particular exclusively, by the second electronic control unit and the outlet valve is actuated, in particular exclusively, by the first electronic control unit.Particularly preferred is a first electrically actuated parking brake provided on the wheel assigned to one of the second output ports, which is actuated by the first electronic control unit, while a second electrically actuated parking brake is provided on the wheel assigned to the other of the second output ports, which is actuated by the second electronic control unit. In the event of a failure of one control unit, the two wheels of the first output ports and one of the wheels of the second output ports can thus be braked hydraulically. The other wheel of the second output ports is braked by means of the parking brake.

[0052] According to a preferred embodiment of the brake control unit, the pressure chamber (30) is connected to the brake line section (60) via only one first electrically actuated pressure switching valve (19), wherein the first electrically actuated pressure switching valve (19) is designed to be normally open and wherein a check valve (20) opening in the direction of the inlet valves (6a-6d) is connected in parallel to the first electrically actuated pressure switching valve (19).

[0053] Particularly preferred are the at least four inlet valves (6a-6d) configured to be normally open and are actuated by the first electronic control unit (A), wherein the outlet valves (7a, 7b) of the first output ports (4a, 4b) are normally closed and are actuated by the first electronic control unit (A), and wherein the outlet valves (7c, 7d) of the second output ports (4c, 4d) are configured to be normally open, wherein at least one of the outlet valves (7c; 7c, 7d) of the second output ports (4c; 4c, 4d) (or both outlet valves (7c; 7c, 7d)) is actuated by the second electronic control unit (B).

[0054] Particularly preferably, the electrically actuated parking brake(s) (50a) or parking brakes (50a, 50b) are actuated by the first electronic control unit (A) which is / are assigned to the second output port (4c) or second output ports (4c, 4d) whose outlet valve(s) (7c, 7d) is / are actuated by the second electronic control unit (B). The other outlet valve (7d) of the second output ports (4d) can be actuated by the first electronic control unit (A), wherein the electrically actuated parking brake (50b) which is assigned to the second output port (4d) whose outlet valve (7d) is actuated by the first electronic control unit (A) is actuated by the second electronic control unit (B).

[0055] Preferably, the pressure chamber of the pressure source is connected to the pressure medium reservoir via a hydraulic connection in which a check valve opening towards the pressure chamber is arranged.

[0056] Preferably, the pressure source does not include a sniffing hole or a connection to the pressure medium reservoir via a sniffing hole.

[0057] The invention also relates to a braking system with an actuating unit for a driver and an electro-hydraulic brake control unit according to the invention. The actuating unit is connected to the brake control unit by transmitting a driver request signal. There is no mechanical-hydraulic connection between the actuating unit and the brake control unit (no hydraulic fallback).

[0058] Further preferred embodiments of the invention will become apparent from the dependent claims and the following description with reference to figures.

[0059] They show schematically Fig. 1 a first embodiment of a brake control unit according to the invention, Fig. 2 a second embodiment of a brake control unit according to the invention, Fig. 3 a third embodiment of a brake control unit according to the invention, Fig. 4 a fourth embodiment of a brake control unit according to the invention, Fig. 5 a fifth embodiment of a brake control unit according to the invention, and Fig. 6 a sixth embodiment of a brake control unit according to the invention.

[0060] In Fig. 1 A first embodiment of a brake control unit 1 according to the invention for a motor vehicle with four hydraulically actuated wheel brakes 5a-5d is shown schematically.

[0061] Brake control unit 1 comprises an unspecified valve block (hydraulic control unit) with one output port 4a-4d for each wheel brake 5a-5d. A pressure fluid reservoir 3, located at atmospheric pressure, is arranged on the valve block. By way of example, the (first) output ports 4a, 4b are assigned to the wheel brakes 5a, 5b of the front axle (front) and the (second) output ports 4c, 4d are assigned to the wheel brakes 5c, 5d of the rear axle (rear).

[0062] The fill level of the pressure medium reservoir 3 is measured by means of a fill level sensor 44.

[0063] Each outlet port 4a-4d is assigned an inlet valve 6a-6d and an outlet valve 7a-7d. A check valve 8a-8d, closing in the direction of the assigned outlet port 4a-4d, is connected in parallel to each inlet valve 6a-6d. The respective outlet port 4a-4d is connected to the pressure medium reservoir 3 via the outlet valve 7a-7d. The inlet valves 6a-6d are, for example, normally open and can be controlled analogously, while the outlet valves 7a-7d are normally closed switching valves.

[0064] For example, the outlet valves 7a-7d are connected to the pressure medium reservoir 3 via a common return line 62.

[0065] An electrically controlled hydraulic pressure source 2 is provided, which is formed by a cylinder-piston arrangement with a pressure chamber 30. The piston 31 of this arrangement can be actuated by an electromechanical actuator with a schematically indicated electric motor 32 and a schematically depicted rotary-translational gear 33. The pressure source 2 is, for example, designed as a single-circuit electrohydraulic linear actuator (LAC) with only one pressure chamber 30. The piston 31 can be advanced by means of the electromechanical actuator to build up pressure (brake actuation direction) and retracted to release pressure. The electric motor is designed as a double-wound electric motor 32 with a first motor winding 34a and a second motor winding 34b. When both motor windings 34a and 34b are energized, the electric motor 32 delivers its full power.In the event that only one of the two motor windings 34a, 34b is controlled, the power of the electric motor 32 is reduced, but pressure can still be built up by means of the pressure source 2, albeit at a reduced level and with reduced dynamics.

[0066] Brake control unit 1, for example, only includes one hydraulic pressure source 2.

[0067] At least one motor angle sensor 43 is provided for controlling the pressure source 2. As an example, a second motor angle sensor 42 is also provided.

[0068] Pressure chamber 30 is hydraulically connected to a brake line section 60 via a (first) electrically actuated pressure switching valve 9. The inlet valves 6a-6d are connected to the brake line section 60. Brake line section 60 thus connects the outlet port of the first pressure switching valve 9 (or 19 in Fig. 6) with each of the inlet ports of the inlet valves 6a-6d. Pressure chamber 30 is connected to the inlet port of the first pressure switching valve 9 (or 19 in Fig. 6 ). The output port of each inlet valve 6a-6d is connected to the associated output port 4a-4d of the brake control unit 1 for the wheel brakes 5a-5d.

[0069] For example, pressure chamber 30 is connected to brake line section 60 via a further electrically actuated (second) pressure switching valve 10. In other words, pressure chamber 30 is hydraulically connected to brake line section 60 via two pressure switching valves 9 and 10 connected in parallel. The pressure switching valves 9 and 10 are normally closed (closed).

[0070] The function of the pressure switching valves 9, 10 is to allow the linear actuator 2 to draw in pressure medium after a volume-consuming pressure modulation (i.e. with the release of pressure medium via the outlet valves into the pressure medium reservoir 3).

[0071] According to an embodiment not shown, the pressure chamber 30 is connected to the brake line section 60 via a (single) electrically actuated, normally open pressure switching valve and a check valve connected in parallel, opening towards the inlet valves 6a-6d (corresponding to as in Fig. 6 shown: first, normally open pressure switching valve 19 with parallel connected check valve 20).

[0072] In the hydraulic connections from the pressure chamber 30 to each of the inlet valves 6a-6d, only exactly one valve is arranged, namely one of the pressure switching valves 9 or 10 (exemplary embodiment of the Fig. 1) or one of the valves 19 or 20 (not shown embodiment). Accordingly, no electrically actuated valve, in particular no valve, is arranged in the brake line section 60 between the first pressure switching valve (9 or 19) and each of the inlet valves 6a-6d. The same applies to the second pressure switching valve 10 and each of the inlet valves 6a-6d. That is, the pressure switching valve(s) 9, 10 are directly connected to all inlet valves 6a-6d without the interposition of a valve.

[0073] A (first) pressure sensor 40 is connected to the brake line section 60, by means of which the pressure generated by the pressure source 2 can be determined.

[0074] To draw pressure medium into the pressure source 2, the pressure chamber 30 of the pressure source 2 is connected to the pressure medium reservoir 3 via a hydraulic connection 61, in which a check valve 14 opening in the direction of the pressure chamber 30 is arranged.

[0075] For example, the return line 62 and the hydraulic connection 61 are formed via a pipe section that is at least partially shared.

[0076] Brake line section 60 is connected, for example, to the pressure medium reservoir 3 via a separating valve device consisting of two electrically actuated separating valves 11, 12 connected in series. The separating valves 11, 12 connected in series are, for example, arranged between brake line section 60 and the hydraulic (suction) connection 61. The two normally open separating valves 11, 12 serve the function of pressure equalization outside of braking operations.

[0077] Electric parking brakes 50a, 50b are provided on the wheels of one of the axles, for example, the rear axle. The electric parking brakes 50a, 50b are controlled and actuated by the brake control unit 1. Advantageously, the rear axle wheel brakes are designed as combined brake calipers with a hydraulic wheel brake 5c, 5d and an integrated, electrically actuated parking brake (IPB).

[0078] Brake control unit 1 further comprises a first electronic control and regulation unit A and a separate, second electronic control and regulation unit B for controlling the electrically actuated components of brake control unit 1 as well as the parking brakes 50a, 50b. The control and regulation units A and B are connected to each other via redundant signal lines 70.

[0079] The arrows A or B on the electrical or electrically actuated components, such as valves and sensors, indicate the assignment to the electronic control unit A or B.

[0080] The electric motor 32 of the pressure source 2 is controlled by the first and the second electronic control and regulating unit in the sense that the first motor winding 34a is controlled (only) by the first electronic control and regulating unit A (marked with arrow A) and the second motor winding 34b is controlled (only) by the second electronic control and regulating unit B (marked with arrow B).

[0081] Valves 6, 7, 9-12 and sensors 40, 42, 43, 44 of brake control unit 1 are each assigned to only one of the electronic control units, i.e., they are controlled exclusively by electronic control unit A or exclusively by electronic control unit B. This avoids the need for complex, dual-controllable valves / valve coils.

[0082] According to the first embodiment, the inlet and outlet valves 6a-6d, 7a-7d, the (first) pressure switching valve 9, and the isolating valve 11 are actuated by the first electronic control unit A. Likewise, the two electric parking brakes 50a, 50b are actuated by the first electronic control unit A. This is indicated by the arrows with A.

[0083] The (second) pressure switching valve 10 and the isolation valve 12 are actuated by the second electronic control and regulating unit B (this is indicated by the arrows with B).

[0084] The signals from the (first) motor angle sensor 43 are fed to the second electronic control unit B and evaluated by it, whereas the signals from the (second) motor angle sensor 42 are fed to the first electronic control unit A and evaluated by it.

[0085] The signals from the (first) pressure sensor 40 are supplied to the first electronic control unit A and evaluated by it, for example.

[0086] Since the control and regulating unit A has information about the pressure generated by the pressure source 2 based on the signals from the pressure sensor 40, the second motor angle sensor 42, which is assigned to the control and regulating unit A, can be dispensed with if necessary.

[0087] If one of the control units A or B fails, the pressure source 2 can still build up pressure by means of one of the motor windings 34a or 34b, albeit at a reduced level and with reduced dynamics. This (central) pressure is applied to all four wheel brakes 5a-5d. The (central) pressure can also be modulated by moving the piston 31 back and forth.

[0088] A potential disadvantage of the first embodiment is the two isolating valves 11, 12, which only serve the function of pressure equalization outside of braking. Two valves represent a significant expense for this function. According to the other embodiments (see Fig. 2-5 (and their description) the pressure equalization function is advantageously taken over by other valves.

[0089] In Fig. 2Figure 1 schematically illustrates a second embodiment of a brake control unit 1 according to the invention for a motor vehicle. The only differences from the first embodiment are a different isolating valve device and an additional check valve 18. The two normally open isolating valves 11, 12 connected in series are replaced by a single (first) isolating valve 13, which is normally closed and is actuated by the second electronic control unit B. Furthermore, a check valve 18, opening towards the outlet port 4d, is connected in parallel to one of the outlet valves, for example, outlet valve 7d.

[0090] The normally closed isolating valve 13 is opened periodically or permanently outside of braking operations. After a failure of the second control unit B, pressure equalization is ensured by opening at least one outlet valve 7a-7d periodically or permanently outside of braking operations. Advantageously, this function rotates among the outlet valves. In the de-energized state, a vacuum in the system is avoided because the check valve 18 is connected in parallel to one outlet valve (7d). Overpressure in the de-energized state due to thermal expansion of the brake fluid must be accepted.

[0091] In the second embodiment, instead of the two parallel-connected, normally closed pressure switching valves 9, 10, the pressure chamber 30 can alternatively (not shown) be connected to the brake line section 60 via a (single) electrically actuated, normally open pressure switching valve with a parallel-connected check valve opening towards the inlet valves 6a-6d (corresponding to as in Fig. 6 shown: first, normally open pressure switching valve 19 with parallel connected check valve 20).

[0092] In Fig. 3Figure 1 schematically illustrates a third embodiment of a brake control unit 1 according to the invention for a motor vehicle. In contrast to the second embodiment, the hydraulic connection from the brake line section 60 to the pressure medium reservoir 30 with the isolating valve 13 is omitted. Furthermore, the inlet and outlet valves of two wheel brakes, advantageously the inlet and outlet valves 6c, 6d, 7c, 7d, which are assigned to one of the axles (for example, the rear axle (Rear)), are actuated by the second electronic control unit B, as in the third embodiment. In this embodiment as well, a check valve 18 opening in the direction of the outlet port 4d is connected in parallel to one of the outlet valves, for example, the outlet valve 7d.The inlet and outlet valves 6a, 6b, 7a, 7b of the other axle (for example, the front axle (front)) are actuated by the first electronic control unit A, as in the second embodiment.

[0093] For example, a second pressure sensor 41 is connected to the brake line section 60, by means of which the pressure generated by the pressure source 2 can be determined. The signals from the second pressure sensor 41 are fed to the other, i.e., the second, electronic control unit B and evaluated by it. Thus, each control unit A and B has the signals from one of the pressure sensors 40 and 41 available.

[0094] The pressure equalization function outside of braking is entirely taken over by the exhaust valves 7a-7d, analogous to the description for the second embodiment.

[0095] Since the wheel pressure modulation valves (i.e., inlet and outlet valves) are assigned to the control units A and B on each axle, pressure equalization is still guaranteed even after the failure of one of the control units A or B.

[0096] The pressure control functions (for example, ABS (anti-lock braking system)) are distributed between both control units and performed jointly by both. This presents a certain disadvantage. However, if one of the control units A or B fails, wheel-specific pressure modulation in one axle remains possible. For this purpose, the two pressure sensors 40, 41 are provided, each assigned to one of the control units A or B.

[0097] In the third embodiment, instead of the two parallel-connected, normally closed pressure switching valves 9, 10, the pressure chamber 30 can alternatively (not shown) be connected to the brake line section 60 via a (first) electrically actuated, normally open pressure switching valve with a parallel-connected check valve opening towards the inlet valves 6a-6d (corresponding to as in Fig. 6 (shown).

[0098] In Fig. 4Figure 4 schematically illustrates a fourth embodiment of a brake control unit 1 according to the invention for a motor vehicle. In contrast to the first embodiment, the hydraulic connection from the brake line section 60 to the pressure medium reservoir 30 with the isolating valves 11, 12 is omitted. Furthermore, the outlet valves 7c, 7d, which are assigned to the rear axle (Rear), are, for example, controllable analogously to the third embodiment and are designed to be normally open. Only the outlet valves 7c, 7d are actuated by the second electronic control unit B, while the remaining inlet and outlet valves 6a-6d, 7a, 7b are actuated by the first electronic control unit A.The inlet and outlet valves 6a, 6b, 7a, 7b of the first outlet ports 4a, 4b and the inlet valves 6c, 6d of the second outlet ports 4c, 4d are actuated by the first electronic control unit A and the outlet valves 7c, 7d of the second outlet ports 4c, 4d are actuated by the second electronic control unit B.

[0099] If the first electronic control unit A fails, all four wheels can be hydraulically braked by the second electronic control unit B closing the normally open outlet valves 7c and 7d. If suitable vehicle signals, in particular wheel speeds, are available to the second control unit B, central pressure modulation for slip control is also possible.

[0100] After failure of the second control unit B, the inlet valves 6c, 6d of the rear axle (Rear) are closed for each braking action. The wheels of the front axle (Front) are braked hydraulically (5a, 5b), and the wheels of the rear axle (Rear) are braked by the electric parking brakes 50a, 50b. Individual wheel modulation remains possible.

[0101] This embodiment has the advantage that both negative and positive pressure are avoided in the de-energized state. The analog function of the exhaust valves 7c, 7d, which is significantly easier to implement on normally open valves than on normally closed valves, allows for selective, comfortable pressure reduction at the rear axle ("axle blending") and also at each individual rear wheel, a function that is particularly desirable during regenerative braking. The valve current requirement during braking is increased, but this is expected to be more than compensated for by the lower current requirement outside of braking. A certain disadvantage can be seen in the fact that, in this concept, the pressure control of each individual rear wheel is distributed across both control units A and B.

[0102] As in Fig. 6As shown schematically, in the fourth embodiment – ​​instead of the two parallel-connected, normally closed pressure switching valves 9, 10 – the pressure chamber 30 can also be connected to the brake line section 60 via a (single) electrically actuated, normally open pressure switching valve 19 and a parallel-connected check valve 20 opening towards the inlet valves 6a-6d. The pressure switching valve 19, like the pressure switching valve 9, is actuated by the first electronic control unit A.

[0103] As mentioned above in connection with the first embodiment, the function of the pressure switching valves 9, 10 is to allow the pressure source 2 to draw in more pressure after a volume-consuming pressure modulation. However, no volume-consuming pressure modulation is provided after the failure of the first control unit A. Accordingly, the two parallel-connected, normally closed pressure switching valves 9, 10, actuated by different control units, can be replaced by a single, normally open pressure switching valve 19, actuated by control unit A.

[0104] The normally open valve 19 should advantageously have a flow resistance similarly low to that of a modern normally closed pressure-switching valve. This problem is mitigated, for example, by connecting a check valve 20 in parallel to the normally open pressure-switching valve 19 in the pressure build-up direction. It is also advantageous to use several check valves in parallel. This allows for a low flow resistance in the pressure build-up direction to be achieved cost-effectively. If the flow resistance in the pressure release direction is too high, rapid pressure reduction can be carried out via the (possibly analogous) outlet valves. An additional advantage of the parallel check valve 20 is its increased robustness compared to a pressure-switching valve that closes due to a fault.

[0105] One advantage of the sixth embodiment of the Fig. 6The advantage is that no valve needs to be energized outside of braking situations.

[0106] As with the description of the Figures 1 to 3 and 5 As mentioned, corresponding alternative embodiments not shown, with valve 19 (and possibly 20), arise in relation to the first, second, third and fifth embodiments.

[0107] Regarding the alternative third embodiment (with a normally open pressure inlet valve 19 combined with four normally closed outlet valves 7a-7d, which handle pressure equalization (without a connection to the pressure medium reservoir via a separating valve device)), it should be noted that after failure of the control unit A, the wheel pressure modulation valves 6c, 6d, 7c, 7d (for example, on the rear axle) are still available, but the pressure source 2 can no longer draw in fluid. The appropriate slip control function on the rear axle is electronic brake force distribution (EBD) without volume consumption.

[0108] A certain disadvantage of the fourth embodiment compared to the embodiments with four normally closed exhaust valves 7a-7d is that the two parking brakes 50a, 50b can no longer be distributed between both control units A and B without loss of function, which is desirable, for example, to eliminate the transmission parking lock. If, in the fourth embodiment, alternatively (only) one of the two parking brakes, e.g., parking brake 50b, were controlled by the second control unit B, then after a failure of the second control unit B, only the front wheels (5a, 5b) and the one rear wheel (50a), whose parking brake is assigned to the first control unit A, could be braked.

[0109] This disadvantage is eliminated by the fifth embodiment of a brake control unit 1 according to the invention, as described in Fig. 5The issue shown schematically has been resolved. As in the fourth embodiment, the exhaust valves 7c, 7d, which are assigned to the rear axle (Rear), are controllable in the same way and are normally open. In contrast to the fourth embodiment, for one of the second output ports 4c, the inlet valve 6c is actuated by the first electronic control unit A and the associated exhaust valve 7c is actuated by the second electronic control unit B, while for the other second output port 4d, the inlet valve 6d is actuated by the second electronic control unit B and the associated exhaust valve 7d is actuated by the first electronic control unit A.At the same time, the electrically actuated parking brake 50a assigned to the second output terminal 4c is actuated by the first electronic control unit A, while the other electrically actuated parking brake 50b assigned to the second output terminal 4d is actuated by the second electronic control unit B.

[0110] If either control unit A or B fails, both front wheels and one rear wheel can be hydraulically braked, while the other rear wheel is braked by the parking brake. For example, if the second control unit B fails, wheel brakes 5a, 5b, and 5d are hydraulically braked, and the parking brake 50a is applied; if the first control unit A fails, wheel brakes 5a, 5b, and 5c are hydraulically braked, and the parking brake 50b is applied. A disadvantage is the asymmetrical modulation of the rear axle. It could be difficult to achieve the same latency in pressure modulation at both rear wheels.

[0111] In the fifth embodiment, instead of the two parallel-connected, normally closed pressure switching valves 9, 10, the pressure chamber 30 can alternatively (not shown) be connected to the brake line section 60 via a (first) electrically actuated, normally open pressure switching valve with a parallel-connected check valve opening towards the inlet valves 6a-6d (corresponding to as in Fig. 6 (as shown). In each of the embodiments, a second pressure sensor 41 is advantageously connected to the brake line section 60, wherein the signals of the second pressure sensor 41 are supplied to and evaluated by the second electronic control unit B (as for the embodiment of the Fig. 4 (described).

[0112] The embodiments described so far have in common that the pressure source 2 is a linear actuator with a double-wound electric motor 32, wherein each control unit A or B controls exactly one of the two motor windings 34a or 34b. For this purpose, motor winding 34a is connected to the first control unit A and the other motor winding 34b to the second control unit B. To control the pressure source 2, each of the two control units A, B comprises a motor processor for processing the motor control functions, a power stage with transistors for providing the phase voltages to the electric motor 32 (e.g., a B6 bridge), and a driver stage (gate drive unit) for controlling the transistors of the power stage.Advantageously, control unit A is supplied by a first electrical power supply, and control unit B is supplied by a second electrical power supply that is independent of the first.

[0113] According to an alternative, second embodiment of the pressure source 2 and its control, which is used in the brake control units 1 of the embodiments of the Figs. 1 to 6In the implementation shown, the pressure source 2 is formed by a cylinder-piston arrangement with a pressure chamber 30 and a piston 31, wherein the piston 31 can be moved forwards and backwards by an electromechanical actuator 32, 33, and wherein the electromechanical actuator comprises a single-wound electric motor 32 with only one motor winding. For controlling the pressure source 2, each of the control units A, B comprises a motor processor for processing the motor control functions, a power stage with transistors for providing the phase voltages to the electric motor 32 (e.g., a B6 bridge), and a driver stage (gate drive unit) for controlling the transistors of the power stage. Thus, each of the control units A, B can provide the phase voltages required for the operation of the electric motor 32. Both power stages (or both control units A, B) are connected to the motor winding of a single-wound electric motor 32.The output stages are designed such that their outputs are high-impedance in the passive state or in the event of a failure of the associated control unit A or B. This allows the motor winding of the electric motor 32 to be controlled by any one control unit A or B, and in the event of a failure of either, the other control unit B or A can take over this task. The motor processor, driver, and output stage are therefore redundantly designed, and the electric motor 32 has a single winding. Advantageously, control unit A is supplied by a primary electrical power supply, and control unit B is supplied by a secondary electrical power supply, independent of the primary one.

[0114] According to an alternative, third embodiment of the pressure source 2 and its control, which is used in the brake control units 1 of the embodiments of the Figs. 1 to 6In its implementation, the pressure source 2 is formed by a cylinder-piston arrangement with a pressure chamber 30 and a piston 31, wherein the piston 31 can be moved forwards and backwards by an electromechanical actuator 32, 33, and wherein the electromechanical actuator comprises a single-wound electric motor 32 with only one motor winding. In addition to the first electronic control unit A and the second electronic control unit B, a third electronic control unit is present. For controlling the pressure source 2, each of the control units A, B includes a motor processor for handling the motor control functions. On the third control unit, redundant (i.e., at least two) output stages with transistors for providing the phase voltages to the electric motor 32 (e.g., a B6 bridge) and redundant (i.e., at least two) driver stages (gate drive units) for controlling the transistors of the output stage are present.The third control unit also includes several relays that allow each motor processor to transmit its output signals to either of the two driver stages, and each driver stage to control each power stage. The outputs of both power stages are connected to the winding of a single-wound motor. Thus, the driver and power stages are redundantly implemented on a third control unit, and the electric motor 32 is single-wound.

[0115] Advantageously, in the third embodiment of the pressure source 2 and its control system, the first control unit A is supplied by a first electrical power supply, and the second control unit B is supplied by a second electrical power supply independent of the first (so-called redundant electrical system). Furthermore, the third control unit is advantageously connected to the two independent power supplies (voltage sources) of the redundant electrical system. Additional relays ensure that the power supply (voltage supply) to the third control unit, or to the driver and output stages, remains operational even if one of the power supplies (voltage sources) fails, by switching to the other power supply (voltage source).

[0116] The third embodiment of the pressure source 2 and its control enables the control of the electric motor 32 in the presence of more electronic dual faults than the second embodiment of the pressure source 2 and its control. Such dual faults include, for example, the simultaneous failure of a driver stage and any output stage, or the simultaneous failure of a motor processor and any driver stage, or the simultaneous failure of an output stage and any voltage source.

[0117] According to an alternative, fourth embodiment of the pressure source 2 and its control, which is used in the brake control units 1 of the embodiments of the Figs. 1 to 6In one possible implementation, the pressure source 2 is formed by a cylinder-piston arrangement with a pressure chamber 30 and a piston 31, wherein the piston 31 can be moved forwards and backwards by an electromechanical actuator 32, 33, which comprises two (e.g., single-wound) electric motors 32. For example, each of the two electric motors controls one of two ball screw drives. The ball screw drives act on the two ends of a balance beam, the center of which is mechanically connected to the piston 31. In normal operation, the ball screw drives move in and out in parallel to move the piston 31 and build up or release pressure in the wheel brakes. If one electric motor fails, the remaining functioning electric motor can still move one end of the balance beam and thus move the piston 31 forwards and backwards. In this case, the force that can be exerted on the piston 31 is lower, and the available range of motion may be reduced.To control the pressure source 2, each of the control units A and B comprises a motor processor for handling the motor control functions, a power stage with transistors for providing the phase voltages to the electric motor 32 (e.g., a B6 bridge), and a driver stage (gate drive unit) for controlling the transistors of the power stage. The power stage of the first control unit A is connected to one electric motor, and the power stage of the second control unit B is connected to the other electric motor. That is, the first control unit A controls the first electric motor 32, and the second control unit B controls the second electric motor 32. Advantageously, control unit A is powered by a primary electrical power supply, and control unit B is powered by a secondary electrical power supply independent of the primary one.

[0118] The electro-hydraulic brake control unit 1 according to the invention is preferably used in a braking system with an actuating unit for a driver and at least two electrically actuated parking brakes 50a, 50b. The parking brakes are particularly preferably arranged on one axle of the vehicle, advantageously the rear axle (Rear). The actuating unit is connected to the brake control unit 1 via a signal to transmit a driver request signal; however, there is no mechanical-hydraulic connection between the actuating unit and the brake control unit 1.

[0119] Several variants of a brake control unit 1 are proposed, which, as a central unit, generates and modulates the pressure for four hydraulic wheel brakes 5a-5d and is specifically suitable for use in a braking system without a mechanical-hydraulic driver backup. Advantageously, the braking system essentially consists of a central electro-hydraulic brake control unit 1 and an actuation unit for the driver, which is connected to the central brake control unit 1 only by means of a fail-safe transmission of a driver request signal. Furthermore, electric parking brakes are provided on one axle (typically the rear axle), which are also controlled by the central brake control unit 1.

[0120] All embodiments are characterized by the requirement that, after any single electrical or electronic fault, it should be possible to brake all four wheels. In contrast, after a mechanical fault, such as a leak, it should be permissible to decelerate the vehicle solely via the dynamic braking function of the electric parking brakes 50a, 50b, possibly with support from an electric drivetrain. A suitable vehicle center of gravity position for this is generally present and assumed in modern vehicles. This requirement is based on the experience that mechanical faults occur significantly less frequently than electronic faults.

[0121] All proposed hydraulic brake control units 1 fulfill the basic requirement of four-wheel braking after an electrical fault, among other things, by being controlled by two separate control units A and B, which are connected via redundant signal lines 70. Furthermore, electrical and / or electronic means are provided that are configured so that, in the event of a failure of the first electronic control unit A, the electromechanical actuator is controlled by the second electronic control unit B and builds up pressure to actuate the wheel brakes 5a-5d, and that, in the event of a failure of the second electronic control unit B, the electromechanical actuator 32 is controlled by the first electronic control unit A and builds up pressure to actuate the wheel brakes 5a-5d.The electrical and / or electronic means are therefore designed in such a way that in the event of a failure of one (or each) of the two control units A or . B, the remaining functional control and regulating units B or A can control the electromechanical actuator of the (single) pressure source 2 with at least part of its power to build up pressure for actuating the wheel brakes in a brake-by-wire operating mode for service braking.

[0122] Furthermore, the brake control unit contains 1 valves and sensors, each of which is assigned to exactly one control and regulation unit A or B.

[0123] The redundant signal lines 70 between the control units A and B prevent the control units from falsely detecting a failure or a fault-free functioning of the other control unit in the event of a fault in one of the signal lines.

[0124] Advantageously, the brake control unit 1 is powered by a redundant electrical system with two independent power sources (first electrical power supply and second electrical power supply), so that both control units A and B are not powered by the same power source. For example, control unit A is powered by the first electrical power supply and control unit B is powered by the second electrical power supply.

Claims

1. An electrohydraulic break controller (1) for a motor vehicle comprising at least two first output ports (4a, 4b) and two second output ports (4c, 4d) for at least four hydraulically actuable wheel brakes (5a-5d), an electrically controllable hydraulic pressure source (2), a first electronic open-loop and closed-loop control unit (A), a second electronic open-loop and closed-loop control unit (B), a pressure medium reservoir (3), in particular under atmospheric pressure, an inlet valve (6a-6d) for each first and second output port (4a-4d), and an outlet valve (7a-7d) for each first and second output port (4a-4d), via which the respective output port (4a-4d) is connected to the pressure medium reservoir (3), wherein the pressure source (2) is formed by a cylinder-piston assembly comprising a pressure chamber (30) and a piston (31), wherein the piston (31) is slidable back and forth by an electromechanical actuator (32, 33), wherein electrical and / or electronic means are provided which are configured such that, if the first electronic open-loop and closed-loop control unit (A) fails, the electromechanical actuator is controlled by the second electronic open-loop and closed-loop control unit (B) and builds up pressure to actuate the wheel brakes (5a-5d), and that, if the second electronic open-loop and closed-loop control unit (B) fails, the electromechanical actuator (32) is controlled by the first electronic open-loop and closed-loop control unit (A) and builds up pressure to actuate the wheel brakes (5a-5d), characterized in that the pressure chamber (30) is connected via a first electrically actuable pressure sequence valve (9, 19) to a brake line section (60) which the at least four inlet valves (6a-6d) are connected to.

2. The electrohydraulic brake controller (1) as claimed in claim 1, characterized in that the electrical and / or electronic means comprise the electromechanical actuator (32, 33) comprising a double-wound electric motor (32) having a first motor winding (34a) and a second motor winding (34b), wherein the first motor winding (34a) is controlled by the first electronic open-loop and closed-loop control unit (A), and the second motor winding (34b) is controlled by the second electronic open-loop and closed-loop control unit (B).

3. The electrohydraulic brake controller (1) as claimed in claim 1 or 2, characterized in that the first pressure sequence valve (9, 19) and at least the inlet and outlet valves (6a, 7a, 6b, 7b) of the first output ports (4a, 4b) are actuated by the first electronic open-loop and closed-loop control unit (A).

4. The electrohydraulic brake controller (1) as claimed in any one of claims 1 to 3, characterized in that the first electrically actuable pressure sequence valve (9) is normally closed and the pressure chamber (30) is connected to the brake line section (60) via a second electrically actuable pressure sequence valve (10) which is normally closed and which is actuated by the second electronic open-loop and closed-loop control unit (B); or that the first electrically actuable pressure sequence valve (19) is normally open.

5. The electrohydraulic brake controller (1) as claimed in any one of the preceding claims, characterized in that no electrically actuable valve, in particular no valve, is arranged in the brake line section (60) between the first electrically actuable pressure sequence valve (9, 19) and each of the inlet valves (6a-6d).

6. The electrohydraulic brake controller (1) as claimed in any one of the preceding claims, characterized in that the inlet and outlet valves (6c, 7c, 6d, 7d) of the second output ports (4c, 4d) are actuated by the first electronic open-loop and closed-loop control unit (A), and that the brake line section (60) is connected to the pressure medium reservoir (3) via a separation valve device comprising at least one first electrically actuable separation valve (12, 13), wherein the first separation valve (12, 13) is actuated by the second electronic open-loop and closed-loop control unit (B).

7. The electrohydraulic brake controller (1) as claimed in claim 6, characterized in that the first separation valve (13) is normally closed, and the separation valve device comprises only the first electrically actuable separation valve (13).

8. The electrohydraulic brake controller (1) as claimed in any one of claims 1 to 5, characterized in that the inlet and outlet valves (6c, 7c, 6d, 7d) of the second output ports (4c, 4d) are actuated by the second electronic open-loop and closed-loop control unit (B).

9. The electrohydraulic brake controller (1) as claimed in claim 7 or 8, characterized in that a non-return valve (18) opening in the direction of the output port (4d) is connected in parallel relative to one of the outlet valves (7d).

10. The electrohydraulic brake controller (1) as claimed in any one of the preceding claims, characterized in that each of the inlet valves (6a-6d) is controllable analogously and is normally open, and each of the outlet valves (7a-7d) is normally closed.

11. The electrohydraulic brake controller (1) as claimed in any one of claims 1 to 5, characterized in that the outlet valves (7c, 7d) of the second output ports (4c, 4d) are normally open.

12. The electrohydraulic brake controller (1) as claimed in claim 11, characterized in that the inlet valves (6c, 6d) of the second output ports (4c, 4d) are actuated by the first electronic open-loop and closed-loop control unit (A), and the outlet valves (7c, 7d) of the second output ports (4c, 4d) are actuated by the second electronic open-loop and closed-loop control unit (B); and / or that for the one second output port (4c), the inlet valve (6c) is actuated by the first electronic open-loop and closed-loop control unit (A), and the outlet valve (7c) is actuated by the second electronic open-loop and closed-loop control unit (B), and that for the other second output port (4d), the inlet valve (6d) is actuated by the second electronic open-loop and closed-loop control unit (B), and the outlet valve (7d) is actuated by the first electronic open-loop and closed-loop control unit (A).

13. The electrohydraulic brake controller (1) as claimed in any one of the preceding claims, characterized in that electrically actuable parking brakes (50a, 50b) are provided on the wheels associated with the wheel brakes (5c, 5d) of the second output ports (4c, 4d), wherein the electrically actuable parking brakes (50a, 50b) are actuated by the first electronic open-loop and closed-loop control unit (A).

14. The electrohydraulic brake controller (1) as claimed in claim 12, characterized in that a first electrically actuable parking brake (50a), which is actuated by the first electronic open-loop and closed-loop control unit (A), is provided on the wheel associated with the one second output port (4c), and that a second electrically actuable parking brake (50b), which is actuated by the second electronic open-loop and closed-loop control unit (B), is provided on the wheel associated with the other second output port (4d).

15. A brake system comprising an actuation unit for a vehicle driver and an electrohydraulic brake controller (1) as claimed in any one of the preceding claims, wherein the actuation unit is connected to the brake controller (1) by transmitting a driver's request signal, and there is no mechanical-hydraulic connection from the actuation unit to the brake controller (1).