Running dynamics system for a vehicle equipped with wheels and method for adjusting braking pressure

Abstract

The present invention relates to a driving dynamics system for a vehicle equipped with wheels (R1 to R4), comprising: - a primary control unit (M-ECU) for detecting and / or forming steering commands and braking commands; - at least two hydraulically operable wheel brakes (RB1 to RB4) respectively associated with one wheel (R1 to R4); - at least one electric traction motor comprising a traction motor control unit and having traction motors (TM1, TM2) arranged for driving at least one of the wheels (R1 to R4), wherein the primary control unit is communicably connected to the traction motor control unit for controlling the traction motors (TM1, TM2) to execute the steering commands and braking commands; - at least one (first) electro-hydraulic pressure supply unit (BM1), wherein at least one of the hydraulically operable wheel brakes is associated with a brake pressure regulating valve and an outflow valve (AV1 to AV4) in the form of a special solenoid valve (MV2k) having particularly tensile resistance, and wherein the driving dynamics system, in particular the primary control unit (M-ECU), is configured to selectively reduce pressure from at least one hydraulically operable wheel brake via the associated outflow valve or via the special solenoid valve (MV2k).

Description

Technical Field

[0001] Title The present invention relates to a driving dynamics system (FDS) having a primary control unit or a central computer (M-ECU) described by the generic concept of claim 1, and a method for adjusting braking pressure.

[0002] Prior Art Since the market introduction of the anti-lock braking system (ABS), anti-slip regulator (ASR), and electronic stability program (ESP) in 1978, 1986, and 1995, respectively, the braking pressure control system for an electro-hydraulic brake (EHC) has been accepted based on a feedback method using pre-pressure via a master brake cylinder. In this case, pressure increase by choking with PWM is performed via an inlet valve, and pressure decrease is performed via time control of an outlet valve. Inside the structural unit, usually, a valve block, an electric motor, a pump, an accumulator chamber, eight solenoid valves (for ABS) or twelve solenoid valves (for ESP), a pressure sensor, and an electronic control unit (ECU) are assembled together and are spatially separated from the brake booster in the engine room and assembled.

[0003] The most widespread use in the market for existing vehicles is the use of an ABS / ESP motor pump unit that combines a vacuum brake booster and a vacuum pump. There are a so-called two-box brake system having an electro-hydraulic brake booster and an ESP unit spatially separated therefrom (German Patent Application Publication No. 102012211278), and a so-called one-box brake system having an integrated brake booster and a pressure modulator (European Patent Application Publication No. 1907253, German Patent Application Publication No. 102013222281), which are standard in new vehicles.

[0004] The hydraulic structure of the ESP unit with 12 solenoid valves as a pressure supply unit has not been changed since the series introduction in 1995. However, due to the interaction between the control device of the electro-mechanical brake booster and the control device of the ESP unit for additional functions, and for the component protection of a more rigid electro-mechanical brake booster, a standardized interface (see VDA360) is defined. Therefore, for specific functions, the solenoid valves of the ESP unit for the specific functions are driven and controlled via the control device. German Patent Application Publication No. 102012211278 describes the drive control of the valve for regenerative braking and the ABS pump.

[0005] The automotive industry is undergoing major changes. In addition to the increasing market penetration of electric vehicles, various levels of autonomous driving (SAE levels 2 to 5) are progressing, where the redundancy requirements for the brake systems used are increasing at each level of autonomous driving (see ATZ-Article 3 / 2019 “Brake Booster for Automated Driving”).

[0006] Also, the central control device of the vehicle is introduced by a control device for chassis control (hereinafter also referred to as “vehicle motor control” or “VMC” or “vehicle chassis control” or “VCC”), which also includes an electro-hydraulic brake, an electric traction motor (trademark) at one or more axles of the vehicle, an electric power steering (EPS), and a damping unit as an optional means. The central control device can make full use of the co-action.

[0007] Since 2020, in the racing series "Formula E" with a powerful electric traction motor for regenerative braking, the "fade strategy" stipulated as a standard in the Bremsenhandbuch 5th Edition (see Chapter 19: "Regenerative Brake Systems"), where the hydraulic braking torque is reduced by only the braking torque of the electric traction motor, has gradually ceased to be pursued. Instead, additionally, the braking torque is formed by the electric traction motor and the electro-hydraulic brake, thereby achieving a reduction in the time (abbreviated as TTL) until the lock braking torque / lock braking pressure is reached. Therefore, the braking distance is shortened by increasing the braking torque as fast as possible.

[0008] Current Limitations and Problems of ABS / ESP Devices According to the Prior Art The problem with the current ABS / ESP brake device equipped with a motor pump unit is that the dynamics for new functions such as, for example, automatic emergency braking AEB ("Automatic Emergency Brake") are limited. For such functions, it is extremely important to form the braking pressure up to the wheel lock pressure (typical values in a passenger car brake system: 80 - 100 bar) in the shortest possible time. While an ABS / ESP brake device equipped with a pump and an electric brush motor reaches a pressure of 50 bar in 450 ms, a one-box brake system equipped with a high-power brushless motor (German Patent Invention No. 102005063659) can reach a wheel lock pressure of 80 - 100 bar in less than 150 ms. A short TTL time could mean that when the initial speed is 65 km / h, the braking distance is shortened by more than 5 m.

[0009] Each ABS / ESP braking device (ABS / ESP braking device equipped with a motor pump unit and one box) has a check valve in the basic mode. These check valves are hydraulically connected in parallel to the inlet valve in the hydraulic line to the wheel brakes for safety considerations, ensuring that the pressure in the wheel brakes is always automatically reduced, i.e., no pressure remains in the wheel brakes in case of a failure of the pressure supply device. However, the technical solution here leads to difficulties or impossibility in diagnosing wheel brake circuit failures because it is unclear whether the check valve or the inlet valve is the cause of the wheel circuit failure. As a result, in error cases, the entire brake circuit including two wheel brakes has to be deactivated. Therefore, the diagonal split (X brake circuit) of the brake circuit is the preferred split in most vehicles. This is because even in case of a brake circuit failure, braking is still possible by the front wheel brakes, which have a greater braking effect than the rear wheel brakes. The so-called "black & white" brake circuit (type II brake circuit) in hybrid or electric vehicles has the drawback that the braking effect decreases in error cases, but has the advantage that the control strategy for regenerative braking can be realized more easily.

[0010] Furthermore, an ABS / ESP braking device equipped with a motor pump unit that performs pressure reduction via a time-controlled outflow valve has drawbacks in terms of braking distance control performance compared to the above-described one-box braking system (see German Patent Application Publication No. 102013222281) that performs pressure reduction into a storage container. This is because the back pressure in the storage container (up to 5 bar) limits the rapid pressure reduction at low pressure during pressure reduction. This causes a slow pressure reduction in the case of ABS control on a road surface with a low friction value, i.e., low μ (due to ice or snow), and therefore, it takes an extremely long time to reduce the wheel speed in ABS control. This leads to a long braking distance. On a road surface with a partially extremely low friction value (ice), ABS can perform only minimal control. Therefore, the standard ABS / ESP device has significantly more serious drawbacks in terms of control operation and braking distance due to its inferior control performance compared to the new standard set by the one-box braking system.

[0011] Problems to be Solved by the Invention The object of the present invention is to provide an improved driving dynamics system, in particular a driving dynamics system in the form of a plurality of pressure supply units (a two-box solution with two separate hydraulic pressure supply units hydraulically connected in series, each with a separate pressure actuator for two wheel brakes). Preferably, it is desirable for the system to solve the above-mentioned problems. The system is preferably small, reliable, accurate, reliable, and highly efficient.

[0012] Also, the driving dynamics system preferably meets the requirements of the autonomous driving mode (SAE level 3 and SAE level 4 with driver intention detection via the E-pedal, or SAE level 5 without a pedal with target value setting by a central computer), and provides a new interface between brake modules or between pressure supply units and / or a new interface between a brake module and a central computer.

[0013] Furthermore, it is desirable that the system incorporates at least one electric traction motor to efficiently provide functions of running dynamics control (ABS, ESP, EBV, ACC, AEB, regeneration management) and individual braking torque intervention for each wheel (BtS: Brake-to-Steer, BtTV: Brake-to-Torque Vectoring).

[0014] Means for Solving the Invention The above problem is solved by the subject matter according to claim 1.

[0015] In particular, the above problem is a running dynamics system for a vehicle equipped with wheels, - a primary control unit that detects and / or forms steering commands and braking commands, - at least two hydraulically operable wheel brakes respectively associated with one wheel, - at least one electric traction motor having a traction motor control unit and with a traction motor arranged to drive at least one of the wheels, where the primary control unit is communicably connected to the traction motor control unit to control the traction motor to execute steering commands and braking commands, at least one electric traction motor, - at least one (first) electro-hydraulic pressure supply unit, · at least one electric motor pump unit, · at least two terminals for connecting the wheel brakes, · an electrically operable wheel brake pressure regulating valve or a brake pressure regulating valve, and · a first secondary control unit comprising at least one (first) electro-hydraulic pressure supply unit and comprising, a brake pressure regulating valve and an outflow valve in the form of a special solenoid valve having particularly tensile resistance are associated with at least one of the hydraulically operable wheel brakes (RB1 to RB4). In a running dynamics system, a running dynamics system, in particular a primary control unit (M-ECU), is configured to selectively reduce pressure from at least one hydraulically operable wheel brake via an associated outflow valve or via a special solenoid valve (MV2k). This is solved by a running dynamics system characterized in that.

[0016] Preferably, the pressure reduction in the first variant is carried out exclusively via the respective outflow valves. In the second variant, pressure reduction can be carried out only via the respective special solenoid valves or simultaneously via the special solenoid valves and the outflow valves.

[0017] Furthermore, the above problem is - a primary control unit for detecting and / or forming steering commands and braking commands, - at least two hydraulically operable wheel brakes, each associated with one wheel, - at least one electric traction motor equipped with a traction motor control unit and having a traction motor arranged to drive at least one of the wheels, where the primary control unit is communicatively connected to the traction motor control unit to control the traction motor to execute steering commands and braking commands, the electric traction motor, - at least one (first) electro-hydraulic pressure supply unit, · at least one electric motor pump unit, · at least two terminals for connecting the wheel brakes, · an electrically operable wheel brake pressure regulating valve or a brake pressure regulating valve, and · a first secondary control unit a first electro-hydraulic pressure supply unit comprising comprising -At least one of the brake pressure regulating valves includes a special solenoid valve with an electromagnetic drive device having a first excitation coil, and a valve operating member or valve tappet is displaceable between a valve open position and a valve closed position via the first excitation coil. It is solved by the running dynamics system.

[0018] Aspect of the present invention is that the special solenoid valve includes a permanent magnet and / or a second excitation coil, and has a force applying device arranged to form at least one holding force acting on the valve operating member or valve tappet. Preferably, the special solenoid valve that can be used as an inlet valve or a wheel inlet control valve has tensile resistance by the above measures.

[0019] By the wheel brake circuit design using a wheel inlet control valve having tensile resistance, the system of the present invention has significantly higher error tolerance than the brake devices according to the prior art, and instead of the conventional (diagonal or black & white) brake circuits for a plurality of wheels, a brake system having a plurality of wheel circuits (individual pressure control devices and / or pressure supply devices for each wheel) can be implemented. For example, a failure of a wheel circuit can be diagnosed and the failed wheel circuit can be separated from the pressure supply device by closing the inlet valve. Thereby, in case of a failure of an (individual) wheel circuit, significantly improved deceleration can be achieved even in an error case by the remaining three wheel circuits, and further yaw moment intervention with three wheels can be performed. Hereinafter, the brake module of the first pressure supply unit including the special solenoid valve described in claim 1 is referred to as ESP-X.

[0020] The detection of steering commands and / or braking commands by the primary control unit can be performed, for example, via a steering wheel sensor or a force-displacement sensor in the E-brake pedal. However, the primary control unit can also be configured to form independent steering commands and braking commands. This is essential during the process of autonomous driving. Similarly, the corresponding commands can also occur based on the realization of safety functions (such as the automatic emergency brake AEB). The steering command in the sense of the present invention does not refer to the specific intervention of the driver using the steering wheel. Instead, in the present invention, the steering command is understood to mean any instruction related to moving the vehicle in a specific direction and further performing trajectory control during the autonomous driving mode. For example, the steering commands here also include commands that cause a change in the yaw moment. Torque vectoring can also be realized by corresponding steering commands and / or braking commands.

[0021] (The first) electro-hydraulic pressure supply device may be an ABS / ESP unit. However, generally, it should be understood as any unit that has a pressure generator in the form of, for example, the above-mentioned motor pump unit and forms the corresponding pressure for the corresponding terminal. The pressure supply unit can also undertake a closed-loop control function and / or an open-loop control function. Therefore, these can be regarded as pressure adjustment modules.

[0022] One aspect of the present invention lies in that the special solenoid valve forms an additional holding force. As a result, the special solenoid valve has tensile resistance, and high pressure can be reduced through this valve. In addition to the holding force, a return force that moves the valve operating member or the valve tappet to the valve open position can also be generated.

[0023] In one embodiment, the primary control unit is configured to drive and control the special control valve in at least one of the selected braking modes such that when the special electromagnetic valve of the first pressure supply unit is opened from the wheel brake associated with the special electromagnetic valve, the pressure is reduced. Preferably, each special electromagnetic valve is associated with the first pressure supply unit of the wheel brake. Based on a configuration having tensile resistance, each special electromagnetic valve can be used not only as an inlet valve but also as a kind of outlet valve. The pressure can be increased and decreased bidirectionally via the same special electromagnetic valve. Therefore, it is possible to enable a (significantly) rapid pressure reduction of the wheel brake associated therewith. This is because the pressure can be reduced via both a plurality of valves (special valves) and the outlet valve. Further, the pressure in the wheel brake can be maintained by closing the valve while the pressure generator is driven at a low pressure and the pressure in the wheel brake is high. Thereby, a new degree of freedom that is extremely advantageous by the primary control unit in the central control strategy is provided.

[0024] In one embodiment, at least one of the plurality of wheel brakes associated with the special electromagnetic valve also has an outlet valve. The corresponding outlet valve can be assigned to the wheel brake. In one embodiment, the outlet valve and the special electromagnetic valve are used simultaneously for pressure reduction, whereby the pressure in each wheel brake can be reduced as quickly and effectively as possible. In particular, the primary control unit is configured to simultaneously drive and control the associated special electromagnetic valve and the outlet valve in at least one of the selected braking modes such that the brake fluid is simultaneously discharged from the wheel brake via the associated special electromagnetic valve and the associated outlet valve.

[0025] In one embodiment, the driving dynamics system has at least one second pressure supply unit. Preferably, the second pressure supply unit includes a piston cylinder unit or a rotary pump, i.e., a dedicated pressure generator. The second pressure supply unit can be connected to at least one input side of the first pressure supply unit to supply brake fluid. In one embodiment, the pressure supply unit not only serves as a pressure reservoir but also functions as a (open-loop controllable / closed-loop controllable) pressure sink or alternatively has the function of at least one valve for pressure reduction (e.g., a central outflow valve, see WO 2020 / 165259, the outflow valve of the ABS / ESP unit). When the inflow valve of the ABS / ESP unit is used for pressure reduction, the pressure reduction is time-controlled by the valve, but PWM control is also possible. For example, when a piston cylinder unit is used, a very low pressure, e.g., a pressure of 1 bar to 5 bar, can be generated by pulling back the cylinder in the piston, and in this case, a rapid pressure reduction in the wheel brake is brought about from the resulting pressure difference. In a (preferred) embodiment, the pressure supply unit supplies brake fluid for the first brake circuit and the second brake circuit, where preferably at least one isolation valve for separating the first brake circuit and / or the second brake circuit is provided. The isolation valve here can be configured similarly or identically to the special electromagnetic valve already described, as will be explained in more detail below.

[0026] Also, a plurality of first pressure supply units can be provided and connected to the second pressure supply unit.

[0027] In one embodiment, the first pressure supply unit is (directly) connected to exactly two wheel brakes. Preferably, these two wheel brakes are associated with each wheel provided on the first axle. In one embodiment, in addition to the first pressure supply unit, at least one further pressure supply unit is provided which is (directly) connected to at least two wheel brakes provided on the second axle. In other words, the further pressure supply unit supplies pressure to two wheel brakes associated with each wheel provided on the second axle. That is, according to the present invention, a plurality of first pressure supply units can be provided as different modules, where each module is associated with each module of a specific axle or is associated with a wheel brake provided on a specific axle. Depending on the vehicle, in addition to the first axle and the second axle, a pressure supply unit can also be provided on yet another axle, where each pressure supply unit of one axle is preferably communicatively connected to a primary control unit for receiving steering commands and braking commands. According to the present invention, a direct connection between a device and another device is to be understood as meaning that a hydraulic connection is provided via a pipeline that is not interrupted by another device such as a valve or a pressure generator.

[0028] In one embodiment (hereinafter also referred to as valve terminal variation I), in an ABS / ESP device according to the prior art, a special solenoid valve is configured which usually has an armature chamber of a valve connected to a wheel brake and a valve seat connected to a pressure supply unit and is open in the non-energized state. The pressure can be increased via pre-pressure control and PWM control of one or more special solenoid valves. The pressure reduction is carried out via time control of the same valve, where, during pressure reduction, based on a configuration having tensile resistance, there is no risk of the special solenoid valve being pulled.

[0029] In another embodiment (valve terminal variation II), the valve seat of at least one special solenoid valve is connected to the wheel brake. Such an arrangement enables the reduction of the pressure in the associated wheel brake with low noise. Based on such an arrangement, the valve opening cross-section can be adjusted, particularly by PWM drive control or current closed-loop control. In this way, decompression choked via the special solenoid valve can be carried out. In this embodiment, the pressure increase via the special solenoid valve can be carried out via time control or volume metering, and this time control or volume metering can be carried out in the second pressure supply unit, for example, by adjusting the rotation angle of a rotary pump or the stroke of the piston in a piston cylinder unit.

[0030] Due to the two shapes of the terminals, the wheel brake can be disconnected from the system by simply closing the circuit to the special solenoid valve. To maintain the special solenoid valve, a low holding current can be applied. The separation can be advantageous when a defect, such as a leak, is detected in each wheel brake.

[0031] In one embodiment, the first supply unit can include a rotary pump connected and configured to increase and decrease the pressure in the wheel brake. Thereby, the rotary pump functions as a pressure sink and can carry out rapid decompression.

[0032] Furthermore, the above problem is a driving dynamics system, - a primary control unit for detecting and / or forming steering commands and braking commands, - four hydraulically operable wheel brakes respectively associated with the wheels, - at least one electric traction motor equipped with a traction motor control unit, and a traction motor is arranged to drive at least one of the vehicle's wheels, where the primary control unit is communicably connected to the traction motor control unit to control the traction motor to execute steering commands and braking commands. at least one electric traction motor, and - at least one first electro-hydraulic pressure supply unit, comprising · at least one electric motor pump unit, · at least two terminals for connecting wheel brakes, · an electrically operable wheel brake pressure regulating valve or brake pressure regulating valve, and · a first secondary control unit and at least one first electro-hydraulic pressure supply unit; and - at least one second electro-hydraulic pressure supply unit arranged with respect to a first brake circuit and a second brake circuit for supplying brake fluid to at least one input side of the first pressure supply unit and comprising wherein the second pressure supply unit is associated with at least one isolating valve in the form of a special solenoid valve for isolating the first brake circuit and / or the second brake circuit, the special solenoid valve includes an electromagnetic drive device with a first excitation coil, and via the first excitation coil, a valve operating member or valve tappet of the special solenoid valve is displaceable between a valve open position and a valve closed position, which is solved by a running dynamics system.

[0033] Alternatively, the above problem is solved by a system for a vehicle, in particular a running dynamics system, having wheels (R1 to R4), in particular as described in the preceding embodiments. The system includes - a primary control unit (M-ECU) for detecting and / or forming steering commands and braking commands, - four hydraulically operable wheel brakes (RB1 to RB4) respectively associated with the wheels (R1 to R4), - at least one electric traction motor (TM1, TM2) having a traction motor control unit (S-ECU-TMHA) and arranged to drive at least one of the vehicle wheels (R1 to R4), where The primary control unit (M-ECU) is communicably connected to the traction motor control unit to control the traction motors (TM1, TM2) to execute steering commands and braking commands. At least one electric traction motor (TM1, TM2), - At least one first electro-hydraulic pressure supply unit (BM1), · At least one electric motor pump unit, · At least two terminals for connecting the wheel brakes (RB1~RB4), · An electrically operable wheel brake pressure regulating valve or brake pressure regulating valve, and · A first secondary control unit (S-ECU1) The first electro-hydraulic pressure supply unit (BM1) provided with - At least one second electro-hydraulic pressure supply unit (BM2) arranged with respect to the first brake circuit (BK1) and the second brake circuit (BK2) to supply brake fluid to at least one input side of the first pressure supply unit, Can be provided with At least one isolation valve (TV1, TV2) in the form of a special solenoid valve (MV2k) for separating the first brake circuit (BM1) and / or the second brake circuit (BM2) is associated with the second pressure supply unit (BM2). The special solenoid valve (MV2k) includes an electromagnetic drive device with a first excitation coil (SP1a). Through the first excitation coil (SP1a), the valve operating member (7) or valve tappet (7a) of the special solenoid valve (MV2k) is displaceable between a valve open position and a valve closed position.

[0034] The above system can be characterized in that the special solenoid valve (MV2k) has tensile resistance by providing a force applying device including, in particular, a permanent magnet (PM) and / or a second excitation coil (SP1b, SP2) and arranged to form at least one holding force (FPM, FEM2) acting on the valve operating member (7) or valve tappet (7a).

[0035] One aspect of the present invention is particularly to provide a force-applying device that includes a permanent magnet and / or a second excitation coil and is arranged to form at least one holding force acting on a valve operating member or a valve tappet, so that a special electromagnetic valve has tensile resistance.

[0036] That is, the special electromagnetic valve can also be used as a separating valve, for example, as part of a second pressure supply unit (hereinafter also referred to as the second brake module BM2). In this case, the second brake module BM2 may not include a separating valve if there is only a hydraulic terminal to the first brake module (FIGS. 9, 10, 15), and is also referred to as the brake module BM2 in an embodiment without a separating valve. Tensile resistance also brings a significant improvement to the system in this case. Generally, according to the present invention, other valves having corresponding tensile resistance can also be used. Such a system is preferably a two-box system in which the first pressure supply unit is part of the first box and the second pressure supply unit is part of the second box.

[0037] When the special electromagnetic valve having the above-mentioned permanent magnet and / or the second excitation coil is used, the special electromagnetic valve can be configured similarly or identically to those already described above. In addition to the holding force described above, the force-applying device can also form a return force.

[0038] By advantageously using the second pressure supply unit for decompression against a low friction value, a new control quality can be achieved even in a low-cost ABS / ESP brake device, and in terms of braking distance performance according to a new one-box brake system (German Patent Application Publication No. 102013222281, Bremsenhandbuch 5.Auflage, Kapitel 20.3 “Integriertes Bremssystem MK C1”), complete competitiveness can be obtained.

[0039] Independently of the configuration of the second pressure supply unit, in one embodiment, the first pressure supply unit can be provided with a rotary pump that increases and decreases pressure according to the rotation direction of the rotary pump, whereby a further degree of freedom in pressure reduction can be obtained. Furthermore, in this embodiment, based on the absence of back pressure in the accumulation chamber, the pressure during ABS operation at a low friction value ("low μ") can be satisfactorily reduced. As a result, a highly accurate and low-cost system can be obtained.

[0040] (Another) In one embodiment, the first pressure supply unit can be configured such that pressure reduction is performed not into the accumulation chamber but into the storage container. This is made possible based on the high safety gain achieved by the special solenoid valve according to the present invention, which is particularly used as an inflow valve, and the ABS control performance is significantly improved.

[0041] In one embodiment, together with the electric traction motor in one or more axles, a braking torque via the electric traction motor and the pressure of the first pressure supply unit and / or the pressure of the second pressure supply unit are simultaneously formed. In this regard, during pressure increase, in order to prevent the rear wheels from locking before the front wheels, electric brake force distribution (EBV) can be performed by the first pressure supply unit and / or the second pressure supply unit. When the wheel lock pressure is reached, according to the present invention, ABS control can be used, and the braking torque of at least one traction motor is extremely rapidly reduced. The corresponding behavior does not pose a safety risk in an electric traction motor driven at a high voltage (>400V, particularly >700V) with a braking torque gradient of >10,000 Nm / s, and is sufficiently rapid for safe reduction of the braking torque, and in some cases already functions in the first control cycle. According to the present invention, this is made possible by the introduction of a central driving dynamics control device FDS, which synchronously drives and controls the electric traction motor TM and the pressure generator unit, and extremely rapidly recognizes the ABS case by evaluating the wheel speed sensors. For this purpose, the primary control unit can be communicatively connected to the wheel speed sensors so as to be able to directly read the corresponding sensor values. By the approach of the present invention, even in the case of an automatic emergency brake, a TTL of 150 ms can be achieved only by pressure formation via the pump of the first brake module BM1. So far, such an equivalent value has only been achievable in a one-box brake system equipped with a high-power brushless motor.

[0042] Alternatively or additionally, according to the present invention (in addition to the electric traction motor), a 6-piston pump or a higher-output brush motor can also be used in the first pressure supply unit, thereby achieving a shorter TTL time. According to the approach here, even a lower-output electric traction motor can achieve a good TTL time, possibly a TTL time of about 150 ms. According to the present invention, the individual means of the one-box concept embodiment can be combined in various ways.

[0043] The pressure supply unit can be configured for both pressure increase and pressure reduction. The first pressure supply unit and the second pressure supply unit can each have one secondary control unit having at least one communication interface. The communication interface here can be used to establish communication with the primary control unit. In particular, measurement signals and operating target values can be exchanged. The special solenoid valve of the second pressure supply unit can be arranged such that the valve seat of the special solenoid valve is (directly) connected to the input side of the first pressure supply unit (valve terminal variation III). Based on the arrangement of the special solenoid valve, the valve opening cross-section can be adjusted particularly by PWM drive control or current closed-loop control. With such a special arrangement, also in this case, the pressure can be choked from the first pressure supply unit via the special solenoid valve, and thus the pressure can be reduced with low noise. In the arrangement here, the pressure increase is preferably performed by time control or volume metering (see the above description for pressure open-loop control / pressure closed-loop control via volume measurement).

[0044] In one embodiment, the primary control unit is configured to perform individual pressure control for each wheel brake or for each brake circuit by driving and controlling at least one special solenoid valve of the first pressure supply unit and / or at least one second pressure supply unit.

[0045] In one embodiment, the primary control unit is configured to detect a wheel circuit failure by pressure measurement when the first pressure supply device or the special solenoid valve of the inlet valve is closed. The corresponding diagnostic method may include measuring whether the pressure drops in the pressure existing in the system, even though all of the related valves are closed. If the pressure is dropping, it can be considered that there is a leak. By closing the special solenoid valve, further pressure increase can be performed in the remaining brake circuit or other wheel circuits without leaks. For example, the pressure can be increased by the piston movement in the second pressure supply unit. If the pressure increase correlated with the piston movement does not occur, the leak location can also be estimated in this case.

[0046] As already explained, the primary control device can be configured to isolate a defective brake circuit by closing at least one of the isolation valves. That is, in a preferred embodiment, individual isolation for each wheel circuit or for each brake circuit can be performed to shield the defective brake circuit or the wheel brake circuit and maintain the function of the remaining system.

[0047] The primary control unit can be configured to perform (axle-by-axle) ABS by controlling at least one of the isolation valves and by (alternating) pressure increase and pressure decrease via the second pressure supply unit. That is, different from the conventional system, the second pressure supply unit can be used to perform at least one (minimal) 1-channel ABS. This provides additional redundancy.

[0048] In one embodiment, the primary control unit is configured to perform (automatic) emergency braking by parallel drive control of the traction motor and at least the first pressure supply unit. The corresponding control strategy can also be realized by the only traction motor.

[0049] The primary control unit can be configured to execute an (automatic) emergency braking function (AEB) or an increase in braking torque, in particular a high braking torque (> 3 m / s 2 vehicle deceleration), by controlling the electric traction motor and the electro-hydraulic brake. When performing emergency braking, the braking torques of the electric traction motor and the first pressure supply unit are increased additively up to a high deceleration (> 5 m / s 2 ), preferably up to the maximum deceleration (> 8 m / s 2 , in particular > 9.5 m / s 2 ). The ABS situation can be identified by evaluating the wheel speed sensors during the emergency braking function, i.e., during a highly dynamic pressure increase. In this case, the primary control device can reduce (centrally) the braking torque of the electric traction motor and / or the electro-hydraulic brake or the braking torque of the vehicle axle at one or more locked wheels.

[0050] In one embodiment, the first electromagnetic drive device comprises at least one first electromagnetic valve drive mechanism and a second electromagnetic valve drive mechanism, wherein the secondary control unit is communicably connected to the first electromagnetic valve drive mechanism to control at least one special electromagnetic valve, and the primary control unit is communicably connected to the second electromagnetic valve drive mechanism to control at least one special electromagnetic valve. This means that the special electromagnetic valve can be actuated by two separately configured control devices, thereby ensuring the continued operation of the special electromagnetic valve even if one of the control devices fails. The communicable connection here may be an electrical connection.

[0051] In one embodiment, the primary control unit is configured to at least temporarily adjust the braking pressure, at least in the selection of the brake in the multiplex method / PCC method, wherein the primary control unit gives an adjustment signal to the second pressure supply unit to increase or decrease the pressure.

[0052] In one embodiment, communication interfaces Int-BM1 and Int-BM2 between the central computer or the primary control unit and the control units of the brake modules (BM1 or BM2), and another interface Int between the control devices of the two brake modules S-ECU1 and S-ECU2 2BM result in a new FDS architecture. The interface Int-2BM is incorporated into the VDA360 standard, which is defined as an interface for the cooperation between an electric follow brake booster device (e.g., product i-Booster) and an ESP-hev brake device for regenerative braking, especially as an interface for the valve operation of the outflow valve of the ESP-hev device. Furthermore, at least one electric traction motor (TM1, TM2, TM3) is incorporated into the FDS. At least one other interface is provided between the central computer and the traction motor, preferably one interface IntTMi between the M-ECU and the secondary control unit (S-ECU-TMi) of each traction motor, especially when the axle includes a plurality of traction motors, or an interface between the M-ECU and the control device of each axle of the vehicle (IntTM HA , IntTM VA ). Such a configuration is advantageous, for example, when each wheel has one traction motor provided on the rear axle for accelerating or braking the wheel individually for each wheel.

[0053] One or more of the communication interfaces may be an electrical connection, a wireless connection, or an optical connection. In this case, preferably two communication paths are selected. The first communication path can be configured redundantly, and the second communication path can be used to inspect the signals of the first communication path. In one embodiment, the signal transmission system 2 is implemented in a 2-Out-of-3 scheme using two different signal transmission types to meet the requirements for SAE level 5 and further eliminate errors in transmission. The 2-Out-of-3 braking system must be maintained in a braking device for SAE level 4 using an E-pedal or SAE level 5 that does not necessarily use a pedal. This is because driver intervention with the brake pedal is no longer available.

[0054] Additionally, the solenoid valve driver of the inlet valve of the first pressure supply unit can also be driven and controlled by the primary control unit. Thereby, solely by the second pressure supply unit and the special solenoid valve in the wheel brake, individual pressure control for each wheel for the steering function, particularly 4-channel ABS or individual braking torque intervention for each wheel, becomes possible independently of the operability between the pressure generator, for example a pump, and the secondary control device of the first pressure supply unit. In one embodiment, the solenoid valve driver, particularly the special solenoid valve, is configured redundantly.

[0055] In one embodiment, the secondary control device of the first pressure supply unit is provided with a solenoid valve electronic circuit that is particularly galvanically isolated from the main control board, and this solenoid valve electronic circuit is supplied with a specific voltage, thereby enabling autonomous operation. For this reason, even when the first pressure supply unit fails completely, a complete ABS can be realized.

[0056] Furthermore, the realization of central driving dynamics control in the domain of the central computer can be easily achieved by a chassis control device incorporating a steering actuator, for example an electric power steering device, and an electric traction motor. The existing software architecture can be substantially retained, and higher-level additional functions requiring cooperation between the steering actuator and the electric traction motor can be easily implemented, for example, within a primary control device. In one embodiment, since the function of the first pressure supply unit is transferred to the primary control unit, the first pressure supply unit is configured only as a pressure actuator.

[0057] The driving dynamics system FDS can include a plurality of the following components as a central driving dynamics control device for a vehicle. That is, - A primary control unit (M-ECU) that detects and / or forms steering commands and braking commands, where The primary control unit has at least one of functional ABS, ESP, ASR, ACC, AEB, regenerative brake, and steering by redundant microcontrollers μC1, μC2, μC3 within the primary control unit, The primary control unit (M-ECU), - At least one electric traction motor TM1, TM2, TM3 for driving and braking wheels, respectively, for each of one secondary control device (ECU-TM1, ECU-TM2, ECU-TM3) or axle control device (ECU-VA, ECU-HA), - At least one brake module (BM1) having hydraulic terminals for a plurality of wheel brakes, - A central vehicle model capable of calculating steering commands and braking commands in consideration of the friction value of the road surface, vehicle speed, and / or dynamic weight distribution during braking, where For braking and steering, at least wheel rotation speed sensors, preferably another sensor (acceleration sensor and / or weight sensor), are read into the primary control unit, The central vehicle model and are included.

[0058] The running dynamics system FDS uses a primary control unit (M-ECU) to ensure that steering commands and braking commands for braking torque modulation (e.g., ABS, ESP, EBV) are · The basic braking torque is formed by an electric traction motor or a brake module BM1 or BM2, and braking torque modulation (e.g., ABS, ESP) is closed-loop controlled via the electric traction motor, or · Braking torque modulation is adjusted jointly by at least one electric traction motor and at least one brake module (BM1 or BM2), or · Braking torque modulation is closed-loop controlled via the electric traction motor at the rear axle, and braking torque modulation is closed-loop controlled via at least one electro-hydraulic brake module (BM1, BM2) at the front axle, and are transmitted to a plurality of secondary control devices.

[0059] FDS can be advantageously utilized such that the brake unit maximizes regeneration and optimizes brake output in various driving situations with respect to the braking situation (comfort braking, emergency braking), road surface characteristics (braking on asphalt, snow, ice, μ-jump, μ-split), and the availability of the brake module. Furthermore, by means of the control via FDS and the regenerative braking via the electric traction motor, it is desirable that the cost of the brake caliper is reduced even when the deceleration is greater than 5 m / s². Through regenerative braking, the thermal load on the friction brake is minimized, enabling the reduction of the disc brake at the front axle or the use of the drum brake at the rear axle.

[0060] In this way, during braking torque modulation, at least one brake module (BM1, BM2) and at least one electric traction motor (TM1, TM2, TM3) are simultaneously driven and controlled via the central primary control unit, and the braking torque command is split between at least one brake module and at least one electric traction motor.

[0061] According to an embodiment of a brake device including at least one brake module (BM1, BM2) and a special solenoid valve preferably directly driven and controlled via the primary control unit, individual braking torque intervention for each wheel can be executed by control via the primary control unit. According to the present invention, in the event of a failure in the wheel circuit, the remaining wheel circuits can continue to be driven by closing the special valve of the failed wheel brake circuit. Furthermore, by centrally driving and controlling at least one traction motor and at least one brake module, the TTL time can be minimized.

[0062] In particular, from these embodiments, the following functions, namely, · Automatic Emergency Braking AEB with high dynamics (50 ms to 180 ms) by common braking torque intervention via the electric traction motor and the brake module, · Individual braking torque intervention for each wheel (Brake to Steer, BtS) or running dynamics (Brake to Torque Vektoring, BtTV) for steering assistance, · Vehicle stabilization (ESP function) when the yaw rate is large, · Individual regenerative brakes for each wheel or for each axle result in advantages.

[0063] According to the present invention, starting from a two-circuit ABS / ESP braking device, new functions and improved fault prevention can be achieved by changing the hydraulic structure and replacing fewer components. Therefore, a three-circuit or four-circuit braking system with significant safety advantages is provided. The vehicle dynamics system FDS can further perform individual braking torque control for each wheel via a pressure interface Int-BM1 for the primary control unit. In this case, individual braking torque control for each wheel or for each axle can be more easily realized via the pressure interface than in the case of a standard ESP unit. The system according to the present invention can further adjust the pressure in individual wheel brakes more accurately and dynamically. By using the system of the present invention, individual braking torque intervention can always be executed in three wheel brakes for each wheel, which brings significant advantages in vehicle stabilization functions and highly dynamic processes, such as AEB with electronic brake force distribution (EBV).

[0064] Furthermore, the running dynamics system meets the redundancy requirements for level 3-5 autonomous driving in SAE (redundant brake boosters, redundant ABS functions, and redundant EBV functions). In addition to the redundant ABS / ESP functions, the system operates with two pressure supply units (so-called two-box braking systems each with one pressure supply unit) in cooperation with an ESP-X unit with a low friction value, i.e., low μ, and an external pressure generator DV2, so that the control performance, particularly as part of the pressure supply unit, is significantly improved compared to the prior art. By advantageously integrating a central computer in the form of a primary control unit into the domain architecture of an electric vehicle, the emergency braking function AEB should be further improved by synchronously setting target values of braking torque to the control devices of one or more electric traction motors and setting target values of braking torque. Therefore, the TTL can be significantly shortened.

[0065] After the braking torque of the electric traction motor acts at different braking torques on only one vehicle axle or on multiple vehicle axles respectively, it is further necessary to control the electronic brake force distribution (EBV), that is, it is necessary to distribute the hydraulic braking torque between the front axle and the rear axle differently from the braking torque in the standard EBV control. The system of the present invention can prevent the wheels of the rear axle from being locked before the wheels of the front axle and the wheels of the front axle from being locked only at a deceleration of 0.85 g. In the case of wheel lock, the ABS intervenes, and in the case of ABS control, the braking torque of the electric traction motor must be taken into account.

[0066] One embodiment of the running dynamics system according to the present invention may be characterized in that at least two, preferably four, inlet valves of the first pressure supply unit are replaced by special solenoid valves that are open in the de-energized state. Different from the prior art, the special solenoid valve having tensile resistance does not have a check valve arranged in a hydraulic path parallel to the inlet valve or incorporated in the inlet valve. As already mentioned in the problem statement according to the prior art, the check valve is used to ensure a more reliable reduction of the braking pressure from the wheel brake even in case of a failure of the braking device or a partial failure of the braking device, for example the pressure supply unit. However, this can be omitted in the system according to the present invention.

[0067] The problem mentioned at the beginning is further solved by a switching valve. The switching valve can be used in particular in connection with the running dynamics system already described. The switching valve can be used on the one hand in the function of the inlet valve (ESP device) and on the other hand in the function of the isolating valve of the second pressure supply unit.

[0068] The switching valve comprises - a valve actuating member or valve tappet, - an armature connected to the valve actuating member or valve tappet, - An electromagnetic drive mechanism having at least one excitation coil for displacing a valve tappet longitudinally between a valve open position and a valve closed position may be included.

[0069] The switching valve may be characterized in that the armature has at least one permanent magnet. In one embodiment, the permanent magnet is arranged such that the valve operating member or the valve tappet is held in the valve open position by the magnetic force formed by this permanent magnet. Preferably, the magnetic force acts even when there is no energization of the electromagnetic drive device. Thereby, particularly when the volume flow travels through the valve, special tensile resistance of the switching valve can be obtained.

[0070] The above-described switching valve can be used as a special electromagnetic valve in the sense of the present invention, similarly to the embodiments of the switching valve described below.

[0071] In one embodiment, at least one ring-shaped permanent magnet or a plurality of permanent magnets are provided in the armature. The ring-shaped magnet or the plurality of permanent magnets can have a magnetic pole direction extending substantially perpendicular to the longitudinal direction.

[0072] In one embodiment, one ring permanent magnet or a plurality of permanent magnets are embedded in a material having ferromagnetic conductive properties in the axial direction and the radial direction.

[0073] In one embodiment, the permanent magnet (PM) and / or the adjacent ferromagnetic magnetic flux guide block are arranged and dimensioned such that the magnetic force displaces the valve tappet from the valve closed position to the valve open position in the non-energized state of the electromagnetic drive device. That is, the valve is a valve that automatically opens during a power failure. This has the special advantages already described, particularly in relation to the above-described running dynamics system.

[0074] The electromagnetic drive device may include a first excitation coil and at least one second excitation coil. That is, there is preferably a redundant excitation coil connected to a separately configured solenoid valve driver. This generally enhances the fail-safety of the valve. Further, the valve can be separately connected to different control units, for example, one of the secondary control units and the primary control unit. Thus, one of the two control units can take over the control via the valve if the other control unit fails.

[0075] In one embodiment, an H-bridge including four switches, particularly power semiconductors, is provided. By means of this H-bridge, electromagnetic fields with different polarities can be formed. As a result, when the excitation coil is energized, the valve can be actively opened and closed according to the connection of the H-bridge and the current direction resulting from passing through the excitation coil. Independently of the current flow direction, it can be operated both during pressure increase and pressure decrease by means of current adjustment using a variable cross-sectional area. The H-bridge enables the inversion of the electromagnetic field by at least one excitation coil and further enables the adjustment of the magnetic field strength. Thereby, the force and amplitude acting on the armature (in the direction of action) can be closed-loop controlled.

[0076] In an (alternative) embodiment, a novel and at the same time low-cost design according to the invention is provided by means of a switching valve, preferably comprising a first soft ferromagnetic circuit EM1 and a second magnetic circuit EM2 formed via a permanent magnet. In one embodiment, the forces of the two magnetic circuits EM1 and EM2 act on the armature of the ball switching valve.

[0077] Some of the switching valves according to the invention can be manufactured at low cost by using many components of a standard solenoid valve (for example, an electromagnetic circuit having an armature diameter and a coil) and only changing the end portion (head portion) of the valve.

[0078] By doing so, a permanent magnet circuit is provided in the head portion, whereby a special solenoid valve integrates a soft iron electromagnetic circuit (EMI) and a second electromagnetic circuit (EM2) formed by a simple permanent magnet into one valve. This embodiment has a great advantage in that existing manufacturing equipment can be used for manufacturing. In this way, the inlet valve can be easily replaced with a special solenoid valve by using typical press-fit assembly techniques, preferably with an unchanged diameter and the same interface to the hydraulic block (HCU), that is, the special solenoid valve can be easily inserted into the unchanged hydraulic block. Furthermore, the ECU (= secondary control unit) that is fitted over the hydraulic block and supports the excitation coil of the solenoid valve needs little or no modification.

[0079] Generally, the aforementioned brake module BM1 having a special solenoid valve (ESP-X) has the following variously different configurations (A to E), that is, A) Configuration A : Brake module BM1 hydraulically connected to a vacuum brake booster device (e.g., as ESP-X), B) Configuration B : Brake module BM1 hydraulically connected to an electrical subsequent brake booster device as described, for example, in German Patent Invention No. 112009004636, C) Configuration C : Brake module BM1 hydraulically connected to an electrohydraulic brake booster device equipped with a pedal feel simulator, D) Configuration D : Brake module BM1 hydraulically connected to a second brake module BM2 and driven via a primary control device and an E-brake pedal, E) Configuration E : Brake module BM1 as an autonomous pressure regulating unit driven via a primary control device, for example, driven as an axle module operating two wheel brakes, or a central hydraulic device for operating four wheel brakes, is available.

[0080] The use of a special valve with tensile resistance (wheel brake circuit having a separation means by closing a special solenoid valve) is, in all configurations A to E, · Diagnosis of leaks via measurement of the pressure increase or volume flow rate during pressure build-up by the pressure supply unit when the valve is closed, · Diagnosis of faults in the wheel brake circuit by measuring the pressure increase or volume flow rate when the valve is open and comparing it with the pressure-volume characteristic curve of a typical wheel circuit measured in advance and stored in the memory, · Discrimination regarding further operation of the wheel brake circuit when the leak is small, · Discrimination regarding separation of the brake circuit by continuous closing of the valve connected to the faulty wheel brake circuit and continuous operation of the three wheel brakes, · Selective pressure reduction via the outflow valve or the special solenoid valve, · Holding of the wheel braking pressure at a low braking pressure in other wheel brakes, is made possible.

[0081] Furthermore, for example, in case of a fault in the excitation coil or a fault in the solenoid valve driver of the outflow valve that is closed in the de-energized state, alternatively, the pressure can be reduced via the inflow valve, thereby increasing the availability of the running dynamics system FDS.

[0082] Since the special solenoid valve is particularly important with regard to function and safety, it is advantageous for this valve to additionally have redundant coils and a solenoid valve driver in addition to a configuration with tensile strength. In the case of an outflow valve that is closed in the de-energized state, such redundant means can be omitted for cost reasons. This is because pressure can still be reduced via the special solenoid valve in the event of a malfunction of the outflow valve. In this way, pressure increase is ensured by redundant means. As a result, the failure probability of the wheel brake circuit can be significantly reduced, and the driving dynamics system can be operated with high reliability in all wheel brake circuits. The redundant means here have extremely great significance particularly in the individual braking torque control for each wheel, for example for functions BtS and BtTV, particularly in the central driving dynamics control via the primary control unit.

[0083] Known pressure control methods may remain unchanged in one embodiment of the present invention, and pressure increase is performed via pre-pressure control of the inflow valve and driving using a variable valve opening cross-sectional area. The solenoid valve is driven as a proportional valve by current closed-loop control or current open-loop control (abbreviated among those skilled in the art as PWM operation of the inflow valve).

[0084] In (another) one embodiment, in pressure control, new degrees of freedom in the control strategy can be utilized. As a result, function improvement and new functions in the ABS operation, for example individual braking torque intervention for each wheel via a pressure interface, can be executed by a central computer. The new functions of the central driving dynamics control are particularly individual braking torque control (BtTV) for each wheel for torque vectoring, braking torque intervention for yaw rate control of the ESP function, or steering function (BtS), and / or individual for each axle or individual regenerative braking for each wheel.

[0085] In one embodiment (valve terminal variation I), the valve seat of the inflow valve, particularly the special solenoid valve, is connected to the brake circuit, and the armature chamber is connected to the wheel brake. Here, the pressure control method A (= standard pressure adjustment mode or EVPWM / AV Δt - A conventional pressure control method is used, i.e., PWM control of the inlet valve during pressure increase and time control of the outlet valve during pressure decrease (Brake Handbook Fig. 20.12.a).

[0086] Alternatively, based on an inlet valve with tensile resistance in valve terminal variation I, pressure control method B (multiplex method / PPC method, hereinafter also referred to as "special pressure adjustment mode I") can also be used. The multiplex method / PPC method has great advantages in ABS control at low road friction values, as shown in Brake Handbook 5th Edition, Chapter 20.4 "Integrated Brake System" - Fig. 20.13. This is because the pressure reduction gradient due to pressure reduction through the piston cylinder unit is not limited by the back pressure of the accumulator chamber, and thus a slight reduction in wheel speed at the locked wheel can be achieved. In particular, an inlet valve with tensile resistance in the form of a special solenoid valve is used in an operating mode corresponding to the switching valve shown in Brake Handbook 20.12b. Advantageously, as a pressure source and a pressure sink, another pressure supply unit, for example, a second pressure supply unit, is used. The second pressure supply unit may include a piston cylinder unit or a rotary pump. Here, the piston of the piston cylinder unit moves forward during pressure increase and backward during pressure decrease, or the rotary pump changes the rotation direction of the pump motor during pressure increase (p auf ) and pressure decrease (p ab ).

[0087] When using pressure control according to pressure control method B and a piston cylinder unit, the PPC method ("Piston Pressure Control"), which is known in the art, can be used, whereby pressure can be increased and decreased highly dynamically using sensor signals, current, piston position, and pressure-volume characteristic curves. Furthermore, with such an approach, the temporal pressure characteristics can be accurately controlled. When a pressure change occurs, the inlet valve is driven to open, and the pressure characteristics are preferably closed-loop controlled solely by volume control via the piston cylinder unit (closed-loop control via a cascaded control circuit by piston travel distance, piston speed, and current of the electric motor), or open-loop controlled (current-proportional pressure open-loop control). During pressure increase, the inlet valve can be driven by time control, or a choke by PWM control (pressure control method B: p auf / p ab : multiplex method / PPC method) can also be performed, and it can also be driven sequentially by the multiplex method / PPC method (p auf : EV PWM ; p ab (1): EV Δt , p ab (2): AV Δt pressure control method). Thereby, using the running dynamics system according to the present invention, different braking pressures can be adjusted simultaneously and with high precision in a plurality of different wheel brakes.

[0088] In one embodiment, during operation, it is switchable between a pressure control method A (standard pressure adjustment mode) and a pressure control method B (special pressure adjustment mode I). Between the pressure control methods, preferably, the pressure control method A is switched to be used for asphalt (high μ) or a jump change in the friction value (μ split) during ABS pressure control, in which case a high pressure change must be achieved in a plurality of wheel brakes simultaneously. The pressure control method B is preferably used on low friction values, such as on snow or ice (low μ). Preferably, the primary control unit is configured to detect various conditions. As long as the primary control unit is appropriately configured in one embodiment, the brake circuit of the running dynamics system can be driven by the pressure control method A, and the second brake circuit can be driven by the pressure control method B.

[0089] In another embodiment (valve terminal variation II), the valve seat of the special solenoid valve is connected to the wheel brake, whereby the pressure can be choked and reduced by a variable valve opening cross-sectional area. In this embodiment, the pressure increase can be performed simultaneously or sequentially using a second pressure supply unit, preferably by piston shift, and based on the multiplex method / PPC method, by time control instead of PWM drive. In this embodiment, preferably, the open-loop control strategy or closed-loop control strategy of the first pressure supply unit or the primary control unit is adapted, so that during pressure reduction, the second pressure supply unit is used as an open-loop controllable or closed-loop controllable pressure sink and pressure source. The pressure difference with respect to the wheel braking pressure is detected by determining the piston position and can be set accordingly. By using such a valve terminal variation II, one or more outflow valves can also be omitted. For example, a special solenoid valve as an inflow valve that is open in the non-energized state and two outflow valves that are closed in the non-energized state can be used at the front axle. In this case, the outflow valve at the rear axle is unnecessary. The corresponding system has high dynamics and low noise generation.

[0090] In valve terminal variation II, according to the present invention, a third pressure control method C(p auf :EV ΔT ;p ab (1):EV PWM , p ab (2):AV ΔT pressure control method) can be used. In this third pressure control method, pressure reduction is performed through variable valve cross-section control of the inlet valve. Compared with valve terminal variation I, the pressure can be reduced simultaneously with low noise through a plurality of inlet valves. This is particularly advantageous for the low-noise closed-loop control operation of electric vehicles. Pressure increase is performed, in one embodiment, through pressure control method B (multiplex / PPC pressure control) or pressure control method C.

[0091] As a result, embodiments having various pressure control methods are obtained, and each pressure control method is summarized and shown in the following table again.

[0092]

Table 1

[0093] According to the present invention, pressure increase (p auf ) and pressure reduction (p ab ) can be executed without redundant means. As an example, pressure increase can be executed only through the inlet valve (EV) exclusively (refer to the table row including "p auf (EV)" in the first column), and pressure reduction is through the outlet valve AV exclusively (refer to the table row including "p ab (AV)" in the first column).

[0094] However, preferably, redundant means are provided as shown in the table. In this case, as redundant means for pressure increase, preferably, redundant electromagnetic coils and a redundant driver for the inlet valve are provided (refer to the table row including "p auf (EV), redundant electromagnetic coil / driver" in the first column).

[0095] In some embodiments, for pressure reduction, redundant means are the outlet valve (in the first column, "pab (See the table including "(AV)") or can be ensured by being performed via an inflow valve (see the table including "p" in the first column). ab (See the table including "(EV)"). If there are no such redundant means on the hardware side and software side, for example, when the electromagnetic coil of the outflow valve fails, pressure reduction via this outflow valve cannot be performed. This is because the valve is closed in the non-energized state, and thus pressure reduction is blocked. As a result, continuous locking of the corresponding wheel brake may occur.

[0096] The running dynamics system according to the present invention generally has the advantage that it can more easily and efficiently provide individual braking torque intervention for each wheel and a new adjustment strategy for regenerative braking. This is because, unlike the prior art, by using special solenoid valves, in at least some embodiments, the pressure in the selected wheel brake can be held while the braking pressure in other wheel brakes can be changed.

[0097] When reducing pressure via a special solenoid valve, unlike the conventional method, in order to return the pressure by reducing pressure via the outflow valve, the pump of the first pressure supply unit must be driven and controlled. This particularly applies to the embodiments according to the above-described configurations (C) and (D). However, in the case of ABS operation with a low friction value ("low μ"), this method is also completely possible in configuration (B). Also in configuration (E), in one embodiment of the first pressure supply unit, for example, in the form of a rotary pump, an open-loop controllable or closed-loop controllable pressure sink is provided, and if this open-loop controllable or closed-loop controllable pressure sink can reduce pressure by reversing the rotation direction, corresponding advantages can be obtained.

[0098] The problem mentioned at the beginning is further solved by a method. In particular, the above problem is a method for adjusting the braking pressure in at least one wheel brake of a braking system, comprising the following steps, namely, - determining that pressure should be reduced from at least one of the wheel brakes, i.e., the target wheel brake; - selecting a pressure reduction mode from a first pressure reduction mode and a second pressure reduction mode; - when the first pressure reduction mode is selected, opening at least one of the outflow valves associated with the target wheel brake to effect pressure reduction; - when the second pressure reduction mode is selected, keeping the outflow valve associated with the target wheel brake in a closed state, opening at least one of the inflow valves associated with the target wheel brake, and forming a pressure difference, preferably in an (external) second pressure supply unit, to effect pressure reduction from the target wheel brake via the inflow valve; The solution is provided by a method including the above steps.

[0099] Thus, one aspect of the present invention lies in the ability to select from different modes, especially according to the situation, for optimal pressure reduction. In at least one mode, pressure reduction is effected via a (special) inflow valve. This enables, on the one hand, improved availability (e.g., operation in case of partial valve failure), and on the other hand, lower pressure fluctuations and thus less noise. That is, · Pressure can be formed even when the outflow valve fails (the outflow valve is closed and de-energized in case of failure), · Pressure reduction can be controlled in a closed loop or an open loop in terms of pressure gradient and / or pressure gradient characteristics via an external pressure source, · Pressure reduction can be effected with low noise via a special valve when selecting valve terminal variation II.

[0100] In the framework of the present invention, keeping a valve, especially an outflow valve, in a closed state does not necessarily require that this valve be operated in any way. Rather, in the present invention, a valve that is closed in a de-energized state, which is often used as an outflow valve, can be kept in a closed state by not applying current and not outputting any kind of operating signal.

[0101] Alternatively, the above problem is a method for performing ABS braking in a vehicle, comprising: - determining a required pressure reduction gradient for at least one wheel brake; - using the required pressure reduction gradient to select a pressure adjustment mode from a plurality of pressure adjustment modes, where the pressure adjustment modes include at least a first pressure adjustment mode and a second pressure adjustment mode; - when the first pressure adjustment mode is selected, reducing the pressure from at least one wheel brake via at least one outflow valve using time control; - when the second pressure adjustment mode is selected, preferably when the outflow valve is closed, reducing the pressure from the wheel brake solely via another solenoid valve, where the pressure from the wheel brake is performed in a pressure sink that can be open-loop or closed-loop controlled via another valve. The method includes the above steps to solve the problem.

[0102] That is, the selection of the mode used for pressure reduction is made depending on the required pressure gradient. Additionally or alternatively, the amount of fluid released or the pressure difference can also be considered during the selection.

[0103] The first pressure adjustment mode may be the standard pressure adjustment mode already described. The second pressure adjustment mode may be a special pressure adjustment mode I.

[0104] In one embodiment, the plurality of pressure adjustment modes include a third pressure adjustment mode, for example, special pressure adjustment mode II. When the third pressure adjustment mode is selected, the reduction of the pressure from at least one wheel brake can be executed at least temporally in parallel via at least one outflow valve associated with the wheel brake and at least one solenoid valve associated with another wheel brake. The other solenoid valve may be the special solenoid valve described in connection with various embodiments. By using the inflow valve and the outflow valve at least temporarily simultaneously for pressure reduction, the pressure can be reduced quickly and efficiently.

[0105] In one embodiment, when the second pressure adjustment mode is selected, adjustment of a low pressure in the pressure sink, in particular a low pressure < 5 bar, preferably < 3 bar, is performed.

[0106] The problem mentioned at the beginning is likewise solved by a primary control unit having instructions for executing at least one of the methods described above.

[0107] Furthermore, the above problem is solved by a vehicle or a drive dynamics system comprising one of the primary control units described above, in particular the last-described primary control unit.

[0108] Another advantageous embodiment results from each dependent claim.

[0109] Hereinafter, the present invention will be described in detail with reference to the drawings using a plurality of examples. The following is shown in the drawings.

Brief Description of the Drawings

[0110]

Figure 1

Figure 2a

Figure 2b

Figure 2c

Figure 3a

Figure 3b

Figure 4a

Figure 4b

Figure 5a

Figure 5b

Figure 6

Figure 7a

Figure 7b

Figure 8a

Figure 8b

Figure 8c

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13a

Figure 13b

Figure 14

Figure 15

[0111] Description of the figures Figure 1 FIG. 1 shows a hydraulic circuit diagram of a first brake module BM1 configured as a standard ESP unit. The first brake module BM1 assumes the function of a first pressure supply unit. The first brake module BM1 includes - four time-controlled outflow valves AV1 to AV4, each associated with one of the wheel brakes RB1 to RB4, and - four PWM-controlled inflow valves EV1 to EV4, each associated with one of the wheel brakes RB1 to RB4, and - four check valves arranged in parallel with respect to one of the inflow valves EV1 to EV4 and thus also associated with one of the wheel brakes RB1 to RB4 each. The check valves are arranged to be blocked during pressure increase in the wheel brakes RB1 to RB4 and to be opened according to the pressure conditions during pressure decrease. Furthermore, the valves HSV1, HSV2 pump the brake fluid via a pump P driven and controlled by a motor M when the valves USV1, USV2 are closed, thereby increasing the pressure. Finally, the pump P and the motor form a Meine 2-piston pump (first pressure generator DV1) having one piston each for each of the first brake circuit BK1 and the second brake circuit BK2. The accumulator chamber Spk enables the accommodation of the brake fluid via the outflow valves AV1 to AV4 during pressure decrease. The arrows indicate the possible flow directions of the brake fluid during pressure increase and pressure decrease.

[0112] The first brake module BM1 according to FIG. 1 provides an ESP function and an ABS function. The ESP function is well known and described in the literature, and 12 solenoid valves are required for the function. For the ABS function, only the inflow valves EV1 to EV4 and the outflow valves AV1 to AV4, i.e., 8 solenoid valves, are required. The first brake module BM1 has two brake circuits BK1, BK2, and these two brake circuits BK1, BK2 are connected to a second pressure supply unit via two connection points. In this case, this is I. a vacuum brake booster according to the prior art, II. Electric follow-up brake booster device and brake pedal, III. Pedal feel simulator and brake booster device having a brake pedal, IV. Second pressure generator DV2 equipped with a valve, It may be any of them.

[0113] The first pressure supply unit in FIG. 1a has a pressure sensor p / u arranged to detect the pressure in the brake circuit BK1.

[0114] The various functions of the latest driving dynamics system are shown in tabular form below.

[0115]

Table 2

[0116]

Table 3

[0117] Figure 2a Figure 2a shows the architecture of the driving dynamics system FDS according to the present invention. The driving dynamics system has a first traction motor TM1 and a second traction motor TM2 at the rear axle HA of the vehicle, and a third traction motor TM3 at the front axle VA. The system can have a brake module BM1 and another brake module as an optional means, for example, a second electro-hydraulic brake module BM2. The main element of the driving dynamics system is the primary control unit M-ECU-Chassis Domaen, abbreviated as M-ECU, which performs closed-loop control of the braking torque from the traction motors TM1, TM2, TM3 and the brake modules BM1, BM2 for the following functions, namely, A) Emergency brake AEB with simultaneous electronic brake force distribution (EBV), B) Individual regenerative brakes for each axle or individual regenerative brakes for each wheel, C) Brake operation via the electric motor in case of failure of the brake module D) Accept for at least one of - individual braking torque intervention for each wheel for steering assistance or vehicle stabilization

[0118] The primary control unit M-ECU transmits target values to various mechanisms, where the target values particularly include target braking torque or braking target pressure. For a specific function, target signals for pressure open-loop control or pressure closed-loop control, such as control signals for solenoid valves and / or pre-pressure for the second brake module BM2, can be set by a second pressure generator DV2 for pressure increase or decrease.

[0119] In one embodiment, the primary control unit M-ECU has an interface to the control device M-ECU AD or the domain of autonomous driving and evaluates further information beneficial for effective and predictive closed-loop control. Such information is, for example, camera information regarding the nature of the road surface (on snow, ice, rain) or information regarding the surrounding environment (distance to the occupants and / or other vehicles).

[0120] Figure 2b Figure 2b shows a so-called two-box brake system including a first brake module BM1 and a second brake module BM2. The first brake module BM1 is configured similarly to the first brake module in Figure 1a and has the functional scope shown above. The second brake module BM2 has a piston cylinder unit (also referred to as a plunger) driven by a spindle drive device. The piston cylinder unit forms the second pressure generator DV2. Two isolation valves TV1, TV2 are provided as part of the second brake module BM2, and these isolation valves TV1, TV2 can separate the brake circuits BK1, BK2 from the second pressure generator DV2, and the core functions, namely - brake boosting; - automatic emergency brake AEB; - Electronic Brake Force Distribution EBV; - 2-channel ABS function in multiplex method / PPC method; can be executed.

[0121] In one embodiment of the present invention, redundant functions for meeting the requirements for autonomous driving in stages 4 and 5 can be provided.

[0122] Two brake modules BM1 and BM2 are provided with control devices hereinafter referred to as secondary control units S-ECU1, S-ECU2a, and S-ECU2b, and these control devices communicate with each other and preferably have an interface function Int 2BM (for example, according to the VDA360 interface definition). Based on the communication means between the brake modules BM1 and BM2 and the (upper-level) control function of the primary control unit M-ECU, these components can interact to perform a predetermined function, for example, braking. Here, the pressure generator of the second brake module performs pressure increase and decrease, and at the same time, valves in the first brake module, such as wheel inlet valves EV1 to EV4 and wheel outlet valves AV1 to AV4, are operated.

[0123] By connecting the brake modules BM1 and BM2 to the primary control unit M-ECU via interfaces IntBM1 and IntBM2 respectively, another function, for example, ABS, ESP, AEB, ACC, and new domain functions, that is, torque vectoring (BtTV), steering intervention by braking (BtS), and regeneration management for electric traction motors TM1, TM2, and TM3 can be executed. In this regard, the brake modules BM1 and BM2 function as slaves, that is, as pure pressure adjustment devices, and can execute set target values, for example, pressure torque values or braking torque target values.

[0124] In at least one operating mode, the interface is used by a primary control unit M-ECU to operate (firstly) two brake modules BM1, BM2 in synchronization. For example, while the piston of a second pressure generator DV2 of the second brake module BM2 is being actuated, one or more solenoid valves of the first brake module BM1 are switched simultaneously. By providing separate interfaces for each brake module, any replacement of the brake modules BM1, BM2 is possible, i.e., the brake modules BM1, BM2 can be purchased from various suppliers. Alternatively, only interfaces IntBM1 or IntBM2 communicatively connected to the primary control unit M-ECU may be provided. In this case, communication with the other unit is performed via a standardized interface Int2BM. In the present embodiment, wheel speed sensors vR1, vR2, vR3, vR4 are redundantly read into one of at least two control devices, for example, secondary control units S-ECU1, S-ECU2a, S-ECU2b and the primary control unit M-ECU, whereby the wheel speed signals can always be transmitted via the interfaces IntBM1, IntBM2, Int2BM.

[0125] In the illustrated embodiment, the second brake module BM2 has a check valve RV NF (alternatively a check valve RV NFInstead of (), a solenoid valve may be used) and is hydraulically connected to the storage container VB. To meet the requirements of autonomous driving in stages 4 and 5, it preferably has two three-phase terminals (2×3), and each of the three phases is driven and controlled by the secondary control units S-ECU2a and S-ECU2b. Here, current sensors i / u and motor angle sensors α / u are provided, and these current sensors i / u and motor angle sensors α / u are preferably configured redundantly as well. They are used for high-precision PPC pressure open-loop control or pressure closed-loop control via the piston position or current. The redundant configuration of some components of the second brake module BM2 can enhance availability. Similar to the configuration of steer-by-wire in SAE stage 5 (two steering actuators, here equipped with 2×3 phase motor terminals and an electronic circuit with partial redundancy), a third fallback level can be formed. For example, even when the pump motor fails and during a partial failure of the motor (motor winding, output stage in ECU2a or ECU2b of the second brake module BM2), it is still possible to form a braking torque and control the braking torque at about 50% of the motor torque. On the output side of the pressure supply device of the second brake module BM2, a pressure sensor p / u, which is mainly used for calibration purposes, is preferably provided. If the relationship between the BM2 braking torque and the current or piston position is formed in other forms, the pressure closed-loop control or pressure open-loop control can be executed without such a pressure sensor. This also realizes further redundancy.

[0126] As separating valves TV1 and TV2 of the (circuit), in the embodiment according to FIG. 2a, two special solenoid valves MV2k are used in the second brake module BM2. The special solenoid valve MV2k is particularly tensile-resistant and is configured to increase and decrease pressure with a large flow rate Q. Preferably, the pressure change is suitable for highly dynamically converting the pressure change for ABS operation in the multiplex method / PPC method (that is, the pressure gradient is > 1000 bar / s, preferably > 2000 bar / s). According to the present invention, the special solenoid valve is designed to have tensile resistance according to the system specifications, that is, according to the maximum braking pressure and the maximum volume flow rate.

[0127] In one embodiment, a special solenoid valve MV2k having a first soft ferromagnetic circuit EM1 and a second magnetic circuit EM2 according to FIG. 4, or a special solenoid valve MV2k having a magnetic circuit EMI and a permanent magnet PM in the armature of the valve according to FIG. 5a is used. When a special solenoid valve MV2k having a permanent magnet PM embedded in the armature is used, as will be described in detail with reference to FIG. 6, an H-bridge is preferably used for current control. In this case, the special solenoid valve MV2k is current-controlled and driven with a variable valve cross-sectional area in both pressure increase and pressure reduction. This enables highly accurate pressure control with particularly little noise in both pressure increase and pressure reduction. In the latter configuration, different magnitudes of magnetic forces can be generated in two moving directions using the magnetic circuit EMI and the excitation coil SP1. Due to the advantageous positioning of the permanent magnet PM, a return force is generated even in the non-energized state, whereby the return spring RF can be omitted. However, according to the present invention, in addition to the permanent magnet PM, at least one return spring RF can be provided, for example, as can be seen from FIG. 4.

[0128] Instead of the valves of FIGS. 4 and 6, as a special electromagnetic valve, a standard valve having a magnetic circuit EM1 without a permanent magnet can also be used. For this, reference may be made to the prior art in a one-box brake system, i.e., reference numerals 26a and 26b in FIG. 1. These valves are designed according to the functions to be performed according to the present invention, in particular the ABS function and the pressure difference and pressure change rate of the ABS function. Depending on the function, a more powerful armature and / or a more powerful magnetic circuit with a larger return spring can be used.

[0129] The first brake module BM1 functions autonomously in the standard pressure adjustment mode (pressure control method A), while the brake module BM2 operates in the pressure control method B. Further, according to the present invention, when the ABS operation is performed at an extremely low road surface friction value (low μ, μ - split), it is possible to switch between the standard pressure adjustment mode, the special pressure adjustment mode I with pressure reduction via a special electromagnetic valve, and the use of the brake module BM2 as a pressure sink having a pressure of <5 bar, particularly <3 bar.

[0130] The switching means here also holds in another embodiment of the brake device having two brake modules in a configuration including an accumulator chamber and a brake module (see FIGS. 3a, 3b, 7a, and 7b), and thus will not be described separately again below.

[0131] FIG. 2c FIG. 2c shows an advantageous connection state of the valve seats VS and the armature chambers of the isolation valves TV1, TV2 to the brake circuits BK1, BK2 (for example, in FIG. 5a). Here, the armature chamber AR is hydraulically connected to the pressure generator DV2 of the second brake module BM2 (for example, in FIG. 5a), and the valve seat of the special solenoid valve MV2k is connected to the brake circuit. With such an arrangement, it is possible to adjust the valve opening cross-sectional area, particularly by PWM control or current control during pressure reduction, and thus realize pressure reduction with low noise. In such an arrangement, pressure increase is performed via volume metering that is open-loop or closed-loop controlled using the second brake module BM2, where the isolation valves TV1, TV2 are preferably time-controlled during pressure increase, and the pressure increase is performed in the multiplex method / PPC method.

[0132] When the special solenoid valve MV2k according to FIG. 5a is used, pressure increase can also be performed by variable valve cross-sectional area through special current control via an H-bridge (see FIG. 6), so that the dead time of the multiplex method / PPC method can be avoided, and pressure increase can be performed simultaneously without high requirements for the drive device. In this embodiment, the connection direction is not important. This is because choking can be performed bidirectionally using the special solenoid valve MV2k according to FIG. 5a. Additionally, optionally, the special solenoid valve MV2k can be driven to have tensile resistance by corresponding energization.

[0133] FIG. 3a (abbreviation ESP-X 3k,i2Mv,4RB,SK,KP ) FIG. 3a (abbreviation ESP-X 3k,i2Mv,4RB,SK,KP ) shows an embodiment according to the present invention of the first brake module BM1 in a configuration as a three-channel brake system with twelve solenoid valves, four wheel brakes RB1 to RB4, an accumulator chamber Spk, and a piston pump, which is different from the standard ESP system in that in the first brake circuit BK1, two inlet valves EV1, EV2 are configured as the special solenoid valve MV2k. The parallel connection of the check valves (see RV in FIG. 1) can be omitted based on the special tensile resistance characteristics of these valves.

[0134] In one embodiment, the special solenoid valve MV2k is provided with redundant electromagnetic coils MSI, MS2 and a redundant solenoid valve driver, enabling redundant operation, or the solenoid valve driver can be driven and controlled via the primary control unit M-ECU. The first brake circuit BK1 corresponds to the front axle brake circuit of the vehicle in the II-braking force distribution in the illustrated embodiment. That is, the wheel brakes RBI, RB2 are the wheel brakes of the front axle VA of the vehicle.

[0135] In an alternative embodiment, X brake circuit distribution may be selected. In the minimum configuration, in this embodiment, the inlet valves EV1, EV2 associated with the wheel brakes RB1, RB2 of the front axle VA can be configured as special solenoid valves MK2k. Such a modification of the standard brake device can achieve a significant improvement. This is because a three-circuit brake system is introduced from a two-circuit brake system, where redundancy in pressure increase and decrease is obtained for two wheel brakes (see wheel brakes RBI, RB2 in Fig. 3a). Different from the prior art, when one of the first wheel brake RB1 or the second wheel brake RB2, for example, the wheel brake RB1 fails, each wheel brake circuit can be separated by closing the inlet valve EVI associated with the defective wheel brake RB1. Thereby, the control operation by the remaining three wheel brake circuits including the wheel brakes RB2 - RB4 can be continued. Additionally, when one of the electromagnetic coils of the outlet valves AV1, AV2 fails, the pressure can be redundantly reduced via each inlet valve EV1, EV2. This assumes that each running dynamics system has a controllable pressure sink, for example, by providing the corresponding second brake module BM2. Such an approach of the present invention can achieve a significant improvement in the achievable deceleration compared to the prior art. This is because, in case of failure, either (a) the wheel brakes RB1, RB2 provided on the front axle VA and the two wheel brakes RB3, RB4 provided on the rear axle HA, or (b) either of the two wheel brakes RB1, RB2 provided on the front axle VA is used for braking.

[0136] In one embodiment, the above interface between the brake modules according to VDA360 is extended such that the inlet valves EV1 to EV4 can also be operated externally, in addition to the interface described in German Patent Application Publication No. 102012211278. This enables selective braking torque intervention for yaw rate control (ESP), torque vectoring via braking torque intervention (BtTV) for each individual wheel, and steering by braking (BtS) by the remaining three brake circuits in the event of a wheel circuit failure. Such an approach according to the present invention further has the advantage that all the functions described in the above table can be left, in particular, within the first brake module BM1 without major software changes. The software component responsible for pressure boosting has to be modified so that additional functions of a three-circuit closed-loop control are provided in the event of a wheel circuit failure. Furthermore, a control strategy that enables pressure regulation for the primary control unit M-ECU can be implemented at low development costs because the pressure by means of special solenoid valves can be maintained in the two wheel brakes RB1 to RB4. Thus, with the specially configured inlet valves EV1 to EV4, the pressure can be increased and reduced individually for each wheel using the second brake module BM2. When individual braking torque closed-loop control or braking torque open-loop control is performed for each wheel, there is no need to perform pressure reduction via the outlet valves AV1 to AV4 (conversion by special solenoid valves according to FIG. 3b of all isolation valves TV1 - TV4) or the outlet valves AV1, AV2 (conversion according to FIG. 3a), and the costly repumping of the brake fluid using the pump P can be omitted. When such a return requirement is eliminated, complex pressure vibration compensation by the second brake module BM2 during return pumping by the first brake module BM1 can be omitted, which has a beneficial effect on noise and wear.

[0137] International Publication No. 2018 / 234387 (pages 23 to 25) describes a fade strategy for a two-box brake system, which can be used for open-loop control and closed-loop control of braking torque during torque vectoring or steering intervention. By using a special solenoid valve MV2k, it is possible to significantly simplify the execution of the fade strategy or individual braking torque intervention for each wheel. Furthermore, more degrees of freedom are obtained. This is because when the pressure supply unit of the second brake module BM2 adjusts another pre-pressure for other wheel brakes, the pressure within the wheel brakes RB1 to RB4 can be maintained.

[0138] In one embodiment, the first brake module BM1 can be extended by two check valves RV1, RV2 which are part of the connection between the pump P and the storage container VB in the brake circuits BK1, BK2 (see the dashed connection in Figure 3a). This enables rapid suction by the pump significantly more quickly than the suction process via another hydraulic resistance based on the combination with the valves HSV1, HSV2 and the second brake module BM2 compared to the prior art.

[0139] Figure 3b (abbreviation ESP-X 4k,MV,4RB,SK,KP ) Figure 3b (abbreviation ESP-X 4k,MV,4RB,SK,KP) shows a first brake module BM1 according to the invention as a four-channel brake system with twelve solenoid valves, four wheel brakes RB1 to RB4, an accumulator chamber Spk and a piston pump KP, which, unlike the standard ESP, differs in that all inlet valves EV1 to EV4 and their check valves RV1 - RV4 (see FIG. 1a) are replaced by one special solenoid valve MV2k each in two brake circuits BK1, BK2. In this embodiment, a four-circuit brake system is provided. In this embodiment, additional degrees of freedom for individual braking torque control for each wheel and a simple pressure interface to the primary control unit M-ECU are provided. By providing a four-circuit brake system in the first brake module BM1, the brake circuit distribution in the second brake module BM2 can be omitted. For example, the second brake module can include a simple master brake cylinder (HZ) with a single piston (so-called single master brake cylinder SHZ) and a pressure chamber, where the master brake cylinder is preferably configured with redundant seals, and the SHZ must be connected to only one brake circuit, for example, only the brake circuit of the front axle brake circuit. If a wheel circuit in the first brake module fails, even if the pump P additionally fails, it is only necessary to ensure that the defective wheel brake circuit is separated. According to the present invention, this can be done by each inlet valve EV1 to EV4, which can be driven and controlled internally and externally. For this purpose, the special solenoid valve MV2k is provided with a redundant coil and a redundant solenoid valve driver.

[0140] Figure 4a Figure 4a shows a first advantageous embodiment of the solenoid valve MV2k, which has tensile resistance and acts bidirectionally and is open in the de-energized state. According to the present invention, the term "bidirectional" can be understood to mean that pressure increase and pressure reduction are performed via the MV2k valve. The special solenoid valve MV2k has, in two flow directions Q, in particular 100 cm 3 / s ~ 120 cm 3 It operates reliably with a large flow rate of / s and a pressure difference between terminals, for example, 160 bar - 220 bar.

[0141] The special solenoid valve MV2k has a typical structure of a solenoid valve with an electromagnetic circuit EM1, an armature 6, and a valve operating member 7. Here, the valve operating member 7 includes a valve tappet 7a that closes the valve seat VS. Further, a return spring RF having a linear force characteristic and acting on the valve operating member 7 is provided. The return spring applies a preload to the special solenoid valve MV2k at the starting position (the position shown in Fig. 4a).

[0142] In particular, regarding the above-mentioned ranges of large pressure changes and flow rates, it is ensured that the special solenoid valve MV2k is not automatically closed by the action of hydrodynamic forces. This is important when there is a high pressure in the armature chamber AR and a low pressure in the hydraulic connection acting on the valve seat VS. In a hydrodynamic flow, a force F hyd is generated, and this force F hyd applies a force to the valve tappet so that the valve tappet is moved in the direction of the valve seat VS. The return spring RF acts against the hydrodynamic force, but in extreme cases, it is not sufficient to actively prevent tension under the action of the hydrodynamic force.

[0143] The magnetic circuit EM1 (see Fig. 4b) generates a current-dependent and position-dependent magnetic force F EMI = f(isp) that moves the armature in the direction of the stopper and the valve tappet 7a in the direction of the valve seat VS via the stroke s. The magnetic force characteristic is non-linear, and with an increase in the small air gap S (see Fig. 4), especially F EMI =(s max - s) n , n = 1,4 - 2 polynomial, gradually increases with an increase in the stroke s or a reduction in the air gap S between the armature 6 and the stopper (smax - s). The current i SPIncreasing it can increase the magnetic force, but it is limited by the saturation of the magnetic circuit. However, the magnetic force can only act in the direction of the valve seat VS. Therefore, when the flow Q starts from the armature chamber, it does not generate a reaction force against the hydrodynamic force F hyd When the valve is closed and energized, the valve can remain closed against the pressure acting on the valve seat. If the flow starting from the valve seat VS can generate a reaction force, operation with a variable opening cross-sectional area is also possible. That is, the special electromagnetic valve MV2k can be driven in the same way as a proportional valve by the variable valve opening cross-sectional area. In technical terms, such a form of control is also briefly referred to as PMW control.

[0144] In order to construct the special electromagnetic valve MV2k with tensile resistance, in the first deformation mode, the permanent magnet PM is provided as a passive force-applying device for amplifying the return force F RF generated by the return spring RF. The permanent magnet circuit includes the permanent magnet PM and the pole plate 10. The permanent magnet is incorporated in the additional armature 6a, and this additional armature 6 is connected to the armature 6 by frictional connection. Since the poles are oriented parallel to the longitudinal direction of the special electromagnetic valve MV2k, the magnetic force F PM of the permanent magnet PM acts additively to the return force F RF , and the total force is F ges =F PM +F RF .

[0145] The magnetic force FPM is characterized in that the force is large when the valve is open and decreases as the stroke s increases. The magnetic force FPM is still large enough to bear the return of a normal armature when the stroke amount s = s max . Considering that with an appropriate design, the magnetic force FEM1 generated through the coil SP2 and the primary magnetic circuit EMI is large enough to overcome the reaction force of the permanent magnet or the return spring, and this can be achieved by the formation of the corresponding characteristic curve of the EM magnetic circuit, the return spring 13 can be replaced.

[0146] Supplementarily or alternatively, an additional restoring force for the first electromagnetic circuit EM1 can also be formed by the second electromagnetic circuit EM2. The second electromagnetic circuit EM2 is generated by the current in the second coil SP2, and the electromagnetic field preferably extends through an additional electric machine 6a made of a ferromagnetic material. Therefore, also in this variant, a hydrodynamic force F that acts against the restoring force FRF of the return spring RF is formed. Also in this variant, the armature 6 is mechanically coupled to the additional armature 6a. hyd In this variant, a force that acts against the force F is formed. Also in this variant, the armature 6 is mechanically coupled to the additional armature 6a.

[0147] As an example, if the force-applying device is dimensioned accordingly, the return spring RF can be omitted.

[0148] The essential aspect of the special solenoid valve MV2k is that the full force F extends substantially linearly over the entire stroke. Preferably, the force increases at the starting position or when leaving the starting position. The characteristic force distribution over the stroke s is shown in FIG. 4b. This figure also shows that in the special solenoid valve MV2k according to the invention, a clearly different force distribution (see FGes) occurs compared to the valves previously used in this area (see the restoring force FRF). Ges In FIG. 5a, a second advantageous embodiment of the special solenoid valve MV2k is shown, which has tensile resistance, is effective in both directions, and is open in the de-energized state. The special solenoid valve MV2k is suitable for the aforementioned use in the first brake module BM1 (as the inlet valves EV1 to EV4) and the second brake module BM2 (as the isolation valves TV1, TV2).

[0149] Figure 5a In FIG. 5a, a second advantageous embodiment of the special solenoid valve MV2k is shown, which has tensile resistance, is effective in both directions, and is open in the de-energized state. The special solenoid valve MV2k is suitable for the aforementioned use in the first brake module BM1 (as the inlet valves EV1 to EV4) and the second brake module BM2 (as the isolation valves TV1, TV2).

[0150] The special solenoid valve MV2k has a typical structure of a solenoid valve having an electromagnetic circuit EMI. The special solenoid valve MV2k has an armature 6, a valve actuating member 7 having a valve tappet 7a, and a valve seat VS. In this embodiment, an annular permanent magnet PM coated with a soft magnetic element is incorporated in the armature 6 (magnetic flux conductor). The magnetic poles of the permanent magnet PM are oriented in a transverse direction with respect to the longitudinal direction of the special solenoid valve MV2k. Alternatively, a plurality of permanently magnets PM correspondingly oriented in the radial direction can also be provided. The electromagnetic field EMI is formed by a coil SP1a extending in a circular orbit within a predetermined portion of the housing of the special solenoid valve MV2k by an exciting current. The electromagnetic circuit EMI extends across the left leg portion of the housing, is conducted through the magnetic flux conductor in the armature across the first air gap, and is closed across the second air gap in the right leg portion. In this case, the two leg portions are arranged in the housing and are ferromagnetic and magnetically conductive. Since the left leg portion and the right leg portion are separated from each other via a large air gap, the electromagnetic field does not close directly from the left leg portion to the right leg portion. In the energized state, magnetic poles are formed on each leg portion, and these magnetic poles selectively attract or repel the permanent magnet PM by the exciting coil SP1a, and thus in the magnetic flux direction, according to the current direction.

[0151] In this embodiment, the remaining armature 6 is made of a non-electromagnetically conductive material. For example, the armature 6 can preferably be made of a low-cost plastic member that also includes the valve actuating member 7. In the starting position, the armature 6 is positioned such that the current conductor comes closer to the left leg portion than the right leg portion. Thereby, the armature 6 receives a force action that opens the valve, equivalent to the force action of the magnetic force FPM and / or the return force FRF in FIG. 4a. This makes it possible to omit the return spring RF. Furthermore, since the configuration of the magnetic circuit is well reproducible, a load is applied to the return force via the current conductor with a slight tolerance with respect to, for example, the return spring RF.

[0152] In the embodiment according to FIG. 5a, the excitation coil SPa is driven and controlled via an H-bridge (see FIG. 6) having four power semiconductors. As a result, the magnetic flux direction can be changed by reversing the current direction. Thereby, the electromagnetic field EMI can increase or reduce the force acting on the permanent magnet PM. The electromagnetic field can also be reversed so that the special solenoid valve MV2k is closed. As a result, the armature 6 can be moved to the right or left in the plane of the figure via current open-loop control or current closed-loop control.

[0153] The described embodiment has the advantage that the valve is extremely simply formed. The H-bridge includes four power semiconductors as can be seen from FIG. 6, and the magnetic flux direction can be determined according to the circuit of the power semiconductors. When the power semiconductors S2 and S3 are connected, the currents i1, i2 generate a first magnetic flux direction. As a result, an N pole is formed on the left leg portion and an S pole is formed on the right leg portion, and the armature 6 is magnetically repelled, that is, the valve is closed. When the power semiconductors S1 and S4 are connected, the current i3 generates a second magnetic flux direction. As a result, an S pole is formed on the left leg portion and the armature is attracted, that is, the valve is opened or held in the open position. The drive control according to the present invention via the H-bridge can even amplify the return force by the permanent magnet PM, whereby the valve has extreme tensile resistance and can be opened extremely quickly. The rapid opening has the advantage that the wasted time during the decompression by the valve opening process, which is typically 2 ms, can be reduced to less than 1 ms. Thereby, rapid decompression without time loss is possible, which advantageously affects the ABS control quality and the braking distance. Furthermore, the cross-sectional area of the special solenoid valve MV2k can be very accurately controlled during pressure increase, and a large valve opening cross-sectional area having the advantage of reduced choke action due to a large valve stroke can be easily realized by this approach. By the drive control according to the present invention via the H-bridge, the special solenoid valve MV2k is current-controlled and can be driven with a variable valve cross-sectional area both during pressure increase and during pressure decrease. This enables high-precision pressure control with particularly little noise both during pressure increase and during pressure decrease.

[0154] In one embodiment, the special solenoid valve MV2k is provided with a large cross-section, whereby the choking effect during pressure increase can be significantly reduced. As a result, the time until the blocking pressure is achieved can be shortened.

[0155] The special solenoid valve MV2k described can omit a plurality of outflow valves AV1 to AV4, and in particular provides a means for omitting two outflow valves in the wheel brakes RB3 and RB4 of the rear axle HA. This is because the 2-channel multiplex operation can be extremely easily performed by such valves.

[0156] Figure 5b Figure 5b shows a graph of the magnetic force FEM1 acting on the armature 6 (see VK for the return force and RC for the return force) versus the distance s. In this case, the limit smax indicated by the dashed line is the maximum interval at which the valve tappet 7a closes the special solenoid valve MV2k. When there is no energization to the special solenoid valve MV2k (i = 0), a relatively high return force that decreases over the distance s occurs at the starting position (s = 0). However, since the return force still acts at the closed position (s = smax; the valve is closed), unwanted pulling in of the valve is prevented. In the case of energization with a negative sign (see i = i3), a significantly strong return force occurs over the entire distance s.

[0157] When the energization with a positive sign (i = i3) is weak, the return force occurs only at positions near the initial position. After the return force here is overcome, a pre-adjusting force that forcibly moves the valve tappet to the closed position acts. When the energization with a positive sign (i = i3) is strong, the pre-adjusting force acts over the entire distance s, whereby the special solenoid valve MV2k can be closed in a controlled state.

[0158] Figure 7a (abbreviation ESP-X 4k,10MV,4RB,SK,KP ) Figure 7a (abbreviation ESP-X 4k,10MV,4RB,SK,KP) shows another embodiment of the first brake module BM1, in which the valves USV1, USV2 are omitted without causing functional limitations. The brake module is of a four-circuit type and has ten solenoid valves, four wheel brakes and two accumulator chambers Spk. This assumes that the first brake module BM1 is driven together with two individual brake circuits BK1, BK2, power is supplied to the two individual brake circuits BK1, BK2, and has separating valves TV1, TV2 in the form of special solenoid valves MV2k (as can be seen, for example, from FIG. 5b). In this case, the separating valves TV1, TV2 take over the functions of the valves USV1, USV2, in particular taking over ESP intervention. To implement the above solution, another interface is required between the brake modules BM1, BM2. This approach has the advantage that the choke resistance between the pressure generator DV2 of the second brake module BM2 and the wheel brakes RB1 to RB4 is reduced, which makes the system more responsive, which is positively noticeable, for example, during emergency braking.

[0159] Figure 7b (abbreviation ESP-X 4k,8MV,4RB,SK,KP ) Figure 7b (abbreviation ESP-X 4k,8MV,4RB,SK,KP ) shows the first brake module BM1 in which the valves USV1, USV2 and the valves HSV1, HSV2 are omitted. The brake module is of a four-circuit type and has eight solenoid valves, four wheel brakes RB1 to RB4, two accumulator chambers Spk and one piston pump KP. To perform the functions of the valves HSV1, HSV2, two check valves RV1, RV2 are provided, and these two check valves RV1, RV2 form a connection to the storage container VB. This leads to further cost reduction without functional limitations and without limitation of the functional range.

[0160] Figure 8a (abbreviation ESP-X 2k,4MV,2RB,SK,KP ) Figure 8a (abbreviation ESP-X 2k,4MV,2RB,SK,KP) shows an embodiment which is a modification of the embodiment according to FIG. 7b. For this embodiment, only 4 valves (2 inlet valves, 2 outlet valves) are required. The first brake module can be used for motorcycles or for the axles of vehicles with multiple axles. The first brake module has exactly 2 terminals for the wheel brakes RBI, RB2, where each wheel circuit can be separated separately via a special solenoid valve MV2k used as a separation valve TV1, TV2.

[0161] In the event of a failure of the wheel brakes RBI, RB2, the remaining wheel brake circuits are still operable and the braking torque can be increased or decreased. The first brake module BM1 is preferably also provided with an interface IntBM1 to the primary control unit M-ECU, whereby the target setting for individual braking torque intervention for each wheel can be set directly via the primary control unit M-ECU. The first brake module BM1 functions autonomously in the standard pressure regulation mode (pressure control method A), and the additional pressure supply device DV2 can also use the pressure control method B. The brake module BM1 can be hydraulically connected at terminals A1, A2 selectively to a separately configured pressure generator DV2 or to the second brake module BM2 at terminal A1, or SHZ can be connected. Similarly, as explained in FIG. 2b, it is possible to switch between the standard pressure regulation mode and the special pressure regulation mode I in the ABS operation.

[0162] FIG. 8b (abbreviation ESP-X 2k,4MV,2RB,VB,MKP ) FIG. 8b (abbreviation ESP-X 2k,4MV,2RB,VB,MKP) shows another embodiment of the first brake module BM1 for two wheel brakes RB1, RB2, where the pressure generator is a pump with a plurality of pistons. The pressure reduction is directly performed into the storage container VB via the outflow valves AV1, AV2. This has a control technical advantage that the control can be significantly improved at low pressures, especially during control on snow and ice. This is because the back pressure of the accumulation chamber Spk does not limit the pressure gradient during pressure reduction. In this embodiment, the special pressure adjustment mode I is not necessary.

[0163] The first brake module BM1 is preferably also provided with an interface IntBM1 to the primary control unit M-ECU, whereby the target setting of the VMC for individual braking torque intervention for each wheel can be directly set via the primary control unit M-ECU. The first brake pressure module BM1 functions autonomously according to the pressure control method A, and the pressure control method B can also be realized using an additional pressure generator DV2.

[0164] Figure 8c (abbreviation ESP-X 2k.4MV,2RB,VB,RP ) Figure 8c (abbreviation ESP-X 2k.4MV,2RB,VB,RP ) shows an embodiment similar to Figure 8a, with the first brake module BM1 for two wheel brakes. A rotary pump RP is provided as the pressure generator DV1, which can increase the pressure and also reduce the pressure by reversing the rotation direction. The special solenoid valves MV2k arranged as the inflow valves EV1, EV2 and connected to the wheel brakes RBI, RB2 are equipped with redundant excitation coils and redundant drivers. Generally, the corresponding redundant equipment according to the present invention is possible in all embodiments.

[0165] Two outlet valves AV1, AV2 associated with each one wheel brake RB1, RB2 are hydraulically connected to a storage container VB for effective pressure reduction. This embodiment is extremely advantageous in that multiple degrees of freedom of pressure reduction available for improving availability in case of partial failure or for improving closed-loop control and pressure control capabilities are obtained. Here, pressure reduction can be performed completely autonomously (as seen from the first brake module BM1) via the outlet valves AV1, AV2. Also, pressure increase and pressure reduction can be performed separately or using an external pressure generator DV2 provided as part of the second brake module BM2. Thus, this embodiment is particularly suitable for use as a preferably centrally controlled low-cost axle module.

[0166] Generally, the rotary pump RP can be used additionally or alone as the first pressure generator DV1 or as the second pressure generator DV2 in all the embodiments described. When used as the first pressure generator DV1 within the first brake module BM1, the check valve RV1 (see, for example, FIG. 3b) between the pump and the storage container VB can be omitted. The advantage of pressure reduction via the rotary pump RP is that the pressure reduction gradient due to the backpressure in the accumulator chamber Spk is not limited, and it can be used to improve the ABS control performance at low pressure even without an external pressure generator DV2.

[0167] The first brake module BM1 according to FIG. 3b preferably also has an interface Int for the primary control unit M-ECU, BM1 by which the target setting of the VMC for individual braking torque intervention for each wheel can be set directly via the primary control unit M-ECU. The first brake module BM1 functions autonomously by the pressure control method A or the special pressure adjustment mode II (where the rotary pump acts as a pressure sink). The pressure control method B (special pressure adjustment mode I) can also be executed using an additional pressure generator DV2.

[0168] Figure 9 FIG. 9 shows an embodiment similar to the embodiment of FIG. 8a. In this embodiment, a (single) hydraulic terminal is provided for the second brake module BM2. By using all the special solenoid valves MV2k in the four wheel brakes RB1 to RB4, the advantages of a four-circuit system are utilized such that the separation of the brake circuit can be omitted.

[0169] The embodiment preferably also has an interface Int-BM1 (not shown) to a central control device, preferably in the form of a primary control unit M-ECU, by means of which the target setting for individual braking torque intervention can be set externally for each wheel. The first brake module BM1 described functions autonomously by means of the pressure control method A and can be extended by the second brake module BM2 for the pressure control method B (special pressure adjustment mode I).

[0170] FIG. 10 FIG. 10 shows a variant embodiment of the embodiment according to FIG. 9 in another embodiment. This embodiment does not have an accumulator chamber Spk. For pressure reduction, the wheel brakes RB1 to RB4 are hydraulically connected to a storage container VB via outflow valves AV1 to AV4. Only one hydraulic terminal is provided for connecting the second brake module BM2. The hydraulic structure is similar to the embodiments according to FIGS. 8b and 8c. The first brake module BM1 is designed for four wheel brakes. This embodiment is suitable as a hydraulically actuated actuator that is drive-controlled via a central computer, for example a primary control unit M-ECU.

[0171] The first brake module BM1 has, as an optional means, an interface Int BM1 (not shown) to the primary control unit, by means of which the target setting for individual braking torque intervention can be set externally for each wheel. This functions autonomously by means of the pressure control method A and the pressure control method B.

[0172] FIG. 11 FIG. 11 exemplarily shows a first inflow valve EVI that can be used in some or all of the described embodiments. The inflow valve EVI is configured as a special electromagnetic valve MV2k and has redundant coils, each of which is energized via a driver. The first driver (left side) is electrically connected to the secondary control unit S-ECU1 of the first brake module BM1 in which each inflow valve is used. The second driver (right side) is connected to two interfaces Int2BM and IntBM1, whereby the second driver can be driven and controlled by at least one of the secondary control units S-ECU2a of the second brake module BM2 and the primary control unit M-ECU. In one embodiment, the secondary control unit S-ECU1 implements pulse width modulation, i.e., PWM control with clock control of the voltage. For this, a simple switch is sufficient. The control by the primary control unit M-ECU or by the second brake module BM2 is preferably performed using current control i = f(t). For this, the aforementioned H-bridge can be used. With the H-bridge, the temporal flow characteristics can be controlled, and greater degrees of freedom are obtained in both the corresponding design and pressure reduction, particularly with respect to valve cross-section control using a variable cross-sectional area. Therefore, the pressure can be increased or decreased with low noise. Depending on the embodiment, the H-bridge can be used as the first driver or the second driver. Alternatively, both drivers can also be operated via PWM control.

[0173] FIG. 12 FIG. 12 shows an outlet valve AVI that can be used in one or all of the described embodiments. The outlet valve AVI has redundant coils, and each of these coils is energized via one driver. The first driver (left side) is electrically connected to the secondary control unit S-ECU1 of the first brake module BM1 in which each outlet valve AVI is used. The second driver (right side) is connected to two interfaces Int2BM and IntBM1, whereby the second driver can be controlled by at least one of the secondary control unit S-ECU2a of the second brake module BM2 and the primary control unit M-ECU. The outlet valve AV is preferably driven in time control in which the opening time is controlled via the voltage U = f(t).

[0174] FIGS. 13a and 13b FIGS. 13a and 13b show the pressure increase (FIG. 13a) and pressure decrease (FIG. 13b) via the second brake module BM2 in order to show the functional modes of the brake modules BM1, BM2 of FIG. 3a. Each volume flow is shown schematically. In the upper right corner, there is a graph of pressure versus time (t) visualizing the pressure characteristics in the wheel brakes RB1, RB2.

[0175] In the embodiment according to FIG. 13a, the pressure increase is carried out sequentially according to the pressure control method B (MUX) in the multiplex method / PPC method using the delay time Δt mux or is carried out using the pressure control method A (EV PWM ), where the pressure increase is carried out simultaneously via pre-pressure control in a plurality of wheel brakes RB1, RB2. In the latter method, preferably one valve, for example the inlet valve EV1, is opened and the other valve, for example the second inlet valve EV2, is driven by PWM control. Alternatively, the two inlet valves EV1, EV2 can also be driven with different PWM frequencies or current profiles for different valve opening cross-sectional areas in order to adjust different pressures with the pre-pressure given in the wheel brakes RB1, RB2.

[0176] During pressure reduction according to FIG. 13b, the pressure reduction in wheel brakes RB1 and RB2 is exemplarily shown. The pressure reduction is carried out sequentially via the outflow valves AV1, AV2 through a special solenoid valve MV2k having a delay time Δt in a closed hydraulic circuit according to the pressure control method B (MUX) in the multiplex method / PPC method, or through the pressure control method A (standard pressure adjustment mode) having an open hydraulic circuit. Therefore, the pressure in the wheel brake RB1 in the multiplex method / PPC method can be reduced, and in parallel, the pressure in the wheel brake RB2 can be increased via the outflow valve. When an emergency rapid pressure reduction is required, the pressure can also be reduced in parallel via the outflow valve and the special solenoid valve using a special pressure adjustment mode II not shown in the figure. When the outflow valve fails, the pressure control method A in the wheel brake can be switched to the multiplex method / PPC method. Due to the substitutability and freedom degree, extremely good control performance can be simulated for any critical driving situation, or additionally redundant 4-channel operation becomes possible. mux According to the control strategy visualized here, the pressure reduction can be carried out after a delay time Δt according to the pressure control method B in the multiplex method / PPC method, or can be carried out through the pressure control method A. In the MUX method via the piston cylinder unit, a target pressure lower than the pressure in the wheel brakes RB1 to RB4 is adjusted. By simultaneous pressure reduction into the accumulator chamber without a delay time via the outflow valves AV1 to AV4, the delay time Δt

[0177] Figure 14 FIG. 14 shows the pressure reduction in the configuration of the brake modules BM1, BM2 described based on FIG. 3b. The volumetric flow is shown schematically. In the upper right corner, there is a pressure graph versus time (t) visualizing the pressure characteristics in the wheel brakes RB1, RB2, RB3, RB4.

[0178] According to the control strategy visualized here, the pressure reduction can be carried out after a delay time Δt mux in the pressure control method B of the multiplex method / PPC method, or can be carried out through the pressure control method A. In the MUX method via the piston cylinder unit, a target pressure lower than the pressure in the wheel brakes RB1 to RB4 is adjusted. By simultaneous pressure reduction into the accumulator chamber without a delay time via the outflow valves AV1 to AV4, the delay time Δt muxIt can be avoided. Therefore, it is not necessary to predict the restrictions in critical driving situations by control. Also, the first brake module BM1 can be optimized with respect to noise because a large pressure gradient is controlled by the MUX method, and thus has no vibrations that generate noise, and a small pressure gradient is realized by the pressure control method A.

[0179] Figure 15 Figure 15 shows a solution according to the invention with two pressure supply units in the simplest and lowest-cost configuration. The brake module BM1 only has 8 solenoid valves as in FIG. 10. In this case, all wheel inlet valves are configured to have special solenoid valves, that is, a brake module BM1 with 4 wheel brake circuits is provided here. As the second pressure supply unit, instead of the piston cylinder unit driven by an electric motor, a rotary pump driven by an electric motor is used. Based on the embodiment with 4 wheel brake circuits, only a hydraulic connection to the brake module BM1 is required. The brake module BM1 functions autonomously, but is preferably assisted by a third brake module BM3 in normal control.

[0180] The pressure reduction is carried out into the storage container via the outflow valve in the standard pressure regulation mode, and also in parallel or alternatively via the rotary pump. Depending on the corresponding rotation direction of the rotary pump, the rotary pump acts as a pressure sink during pressure reduction. In addition to high safety against errors, this embodiment provides a number of degrees of freedom, and in particular, switching means from the standard pressure regulation mode (pressure increase via the inlet valve and pressure reduction via time control of the outflow valve) to the special pressure regulation mode I and / or the special pressure regulation mode II are also provided. When the first brake module BM1 fails, the rotary pump takes over the pressure increase function, and at the same time, the wheel pressure control valves are driven and controlled via the communication interfaces (Int2BM, IntBM1) shown in FIGS. 11 and 12 via the primary control unit M-ECU or another secondary control device S-ECU2a, S-ECU2b.

[0181] In the foregoing description, the special solenoid valve has been described as a special solenoid valve provided with a force applying device, where the force applying device mainly includes a permanent magnet and / or a second excitation coil, and is arranged to form at least one holding force acting on the valve operating member or the valve tappet. In at least some of the described embodiments and examples, the special solenoid valve may be a solenoid valve having any tensile resistance. Therefore, it can be achieved by providing at least one choke for controlling the tensile resistance such that the volume flow is so small that it does not lead to the closing of the valve.

[0182] Generally, the pulling-in action can be restricted by the pressure difference restriction in the closed-loop control of the pressure supply unit or preferably by a choke (not shown). The choke is preferably mounted in front of the armature terminal of the valve terminal in the hydraulic line.

[0183] In some embodiments of the special solenoid valve, the return spring RF can be omitted.

[0184] Furthermore, in at least one of the described embodiments, the driving dynamics system can be configured such that a simple application of core functions via the primary control unit M-ECU, particularly with high computing power, is automatically possible in the application of functions in development. In at least one of the above-described embodiments, during vehicle operation, assistance can be provided via a learning algorithm or artificial intelligence (AI). When AI is used, the primary control unit M-ECU can take over the tasks of the application engineer, which is impossible with a microcontroller according to the prior art (i.e., one of a closed-loop control unit or an open-loop control unit of a brake system based on extremely limited capabilities and limited accumulators). Thus, the central computer records measurement data during vehicle operation, evaluates it, and applies various functions, particularly safety-critical functions such as ABS, ESP, and AEB, during vehicle operation or in a vehicle stationary state where the vehicle is not moving and thus adaptation is not time-critical. Therefore, adaptation is performed when the vehicle stops, particularly after vehicle operation. Here, a preferred embodiment as a closed hydraulic system that mainly increases and decreases pressure via a valve acting bidirectionally using a pressure supply unit has significant advantages. Because a non-linear relationship can be mapped by a suitable sensor via a characteristic map (e.g., pressure-volume characteristic curve, relationship between motor current and braking pressure, relationship between braking pressure and deceleration during heating of the wheel brake), and adaptation can be performed to detect environmental influences (e.g., air in the system, heating of the wheel brake) during operation. If the non-linear relationship is mapped to a mathematical function or characteristic map, automatic application of the electro-hydraulic braking system can also be performed. When the Al approach is consistently implemented in a hydraulic braking system (EHC), the advantages of an electromechanical brake (EMB) that can be easily closed-loop controlled or open-loop controlled are diminished, and the advantage of reducing the manufacturing cost of the hydraulic braking system becomes even more effective. Because the disadvantages in application costs are significantly eliminated.

Description of Reference Numerals

[0185] M-ECU Primary control unit, central computer R1~R4 Wheels vR1~vR4 Wheel speed sensors RB1~RB4 Wheel brakes BK1,BK2 Brake circuits A1,A2 Terminals BM1 First brake module BM1BE Structural unit of the first brake module DV1 Pressure generator M Motor P Pump unit Spk Accumulation chamber S-ECU1 Control device for the first brake module RP Rotary pump KP Piston pump MKP Multi-piston pump BM2 Second brake module BM2BE Structural unit of the second brake module DV2 Pressure generator S-ECU2a Control device for the second brake module S-ECU2b Control device for the second brake module TV1,TV2 Isolation valves BM3 Another brake module RV,RV1,RV2 Check valves AV1,AV2,AV3,AV4 Outflow valves EV1,EV2,EV3,EV4 Inflow valves HSV1,HSV2,USV1,USV2 Valves of the ESP unit MV2k Special solenoid valve for pressure increase and decrease TM1 First electric traction motor for driving the vehicle axle or wheels TM2 Second electric traction motor for driving the vehicle axle or wheels TM3 Third electric traction motor for driving the vehicle axle or wheels VB Storage container VA Front Axle HA Rear Axle Return Force by FRF Spring FPM Magnetic Force FEM1, FEM2 Magnetic Forces PM Permanent Magnet EM1, EM2 Magnetic Circuits RF Return Spring SP1, SP1a, SP1b, SP2 Excitation Coils 6 Armature 6a Additional Armature 7 Valve Operating Member 7a Valve Tappet 10 Pole Plate 13 Return Spring VS Valve Seat AR Armature Chamber MS1, MS2 Magnetic Coils S Air Gap S1~S4 Power Semiconductors

Claims

1. A driving dynamics system for a vehicle equipped with wheels (R1 to R4), A primary control unit (M-ECU) that detects and / or generates steering commands and braking commands, At least two hydraulically operated wheel brakes (RB1 to RB4) are associated with one wheel each (R1 to R4), An electric traction motor comprising a traction motor control unit, wherein a traction motor (TM1, TM2) is arranged to drive at least one of the wheels (R1 to R4), wherein, The primary control unit is communicated to the traction motor control unit in order to control the traction motors (TM1, TM2) in order to execute steering commands and braking commands. At least one electric traction motor, At least one (first) electrohydraulic pressure supply unit (BM1), At least one electric motor pump unit, At least two terminals for connecting the aforementioned wheel brakes (RB1 to RB4), Electrically operated wheel brake pressure regulating valve or brake pressure regulating valve (AV1 to AV4, EV1 to EV4), and First secondary control unit (S-ECU1) A (first) electrohydraulic pressure supply unit (BM1) comprising: Equipped with, At least one of the hydraulically operated wheel brakes (RB1 to RB4) is associated with a braking pressure regulating valve and outlet valve (AV1 to AV4) in the form of a special solenoid valve (MV2k) that has particular tensile strength. In the driving dynamics system, The aforementioned driving dynamics system, particularly the primary control unit (M-ECU), is configured to selectively reduce pressure from the at least one hydraulically operable wheel brake via the associated outlet valve or via the special solenoid valve (MV2k). A driving dynamics system characterized by the following.

2. The at least one braking pressure regulating valve is a special solenoid valve (MV2k) equipped with an electromagnetic drive device having a first excitation coil (SP1, SP1a), wherein the valve operating member (7) or valve tappet (7a) is displaceable between the valve open position and the valve closed position via the first excitation coil (SP1, SP1a), The special solenoid valve (MV2k) has a force-applying device which includes a permanent magnet (PM) and / or at least one second excitation coil (SP1b, SP2) and is arranged to form at least one holding force (FEM2, FPM) acting on the valve operating member (7) or the valve tappet (7a), and / or The primary control unit (M-ECU) is configured to drive and control the special solenoid valve (MV2k) and the first pressure supply unit (BM1) in at least one of the selected braking modes such that the pressure is reduced when the special solenoid valve (MV2k) is released from the wheel brakes (RB1 to RB4) associated with the special solenoid valve (MV2k). The driving dynamics system according to claim 1.

3. The primary control unit (M-ECU) is configured to drive and control the associated special solenoid valve (MV2k) and the associated outlet valves (AV1 to AV4) in at least one of the selected braking modes, so that brake fluid is simultaneously discharged from the wheel brakes via the associated special solenoid valve (MV2k) and the associated outlet valves (AV1 to AV4). The driving dynamics system according to claim 1.

4. At least one second pressure supply unit (BM2) is provided, arranged with respect to the first brake circuit (BK1) and the second brake circuit (BK2) to supply brake fluid to at least one input side of the first pressure supply unit, wherein the second pressure supply unit (BM2) preferably includes a piston cylinder unit or a rotary pump, where, Preferably, at least one separation valve is provided to separate the first brake circuit and / or the second brake circuit. The driving dynamics system according to claim 1.

5. The first pressure supply unit (BM1) is connected (directly) to exactly two wheel brakes (RB1-RB4), and the exactly two wheel brakes (RB1-RB4) brake the wheels provided on the first axle, and / or A separate pressure supply unit (BM3) is provided, which is (directly) connected to at least two wheel brakes (RB1 to RB4) located on the second axle. The driving dynamics system according to claim 1.

6. The special solenoid valve (MV2k) is configured to be open when no power is supplied, and the valve seat of the special solenoid valve is arranged to be (directly) connected to at least one of the wheel brakes (RB1 to RB4). The driving dynamics system according to claim 1.

7. The primary control unit (M-ECU) is configured to detect a failure in at least one wheel brake circuit, including one of the wheel brakes (RB1 to RB4), and to close a special solenoid valve (MV2k) associated with the wheel brake (RB1 to RB4) in order to isolate the wheel brake circuit. The driving dynamics system according to claim 1.

8. The first pressure supply unit (BM1) includes a rotary pump connected and configured to increase or decrease the pressure of the wheel brakes (RB1 to RB4), The driving dynamics system according to claim 1.

9. The special solenoid valve (MV2k), in particular the special solenoid valve (MV2k) associated with the second pressure supply unit (BM2), is arranged such that the valve seat of the special solenoid valve is (directly) connected to the input side of the first pressure supply unit (BM1). The driving dynamics system according to claim 1.

10. When the pressure is reduced, at least one of the special solenoid valves (MV2k) is driven and controlled, particularly by PWM drive control or current closed-loop control, so that a variable valve opening cross-sectional area is formed. The driving dynamics system described in claim 1.

11. The actuators of the first secondary control unit (S-ECU1) and / or the second secondary control units (S-ECU2a, S-ECU2b), and / or the first pressure supply unit (BM1) and / or the second pressure supply unit (BM2), and / or the sensors of the first pressure supply unit (BM1) and / or the second pressure supply unit (BM2) are communicateable to the primary control unit (M-ECU), particularly via communication interfaces (IntBM1, IntBM2), in order to execute steering commands and / or braking commands. The driving dynamics system according to claim 1.

12. The aforementioned primary control unit (M-ECU) is By driving and controlling at least one of the special solenoid valves of the first pressure supply unit and / or at least one of the second pressure supply units, individual pressure control is performed for each wheel brake, and / or When the special solenoid valve of the first pressure supply device or inlet valve is closed, a wheel circuit fault is detected by pressure measurement, and / or By closing at least one of the separation valves (TV1, TV2), the defective brake circuit is isolated, and / or ABS (per axle) is performed by controlling at least one of the separation valves (TV1, TV2) and by alternating pressure increases and decreases via the second pressure supply unit, and / or By controlling at least one of the special solenoid valves (MV2k) and in particular the outlet valve of the first pressure supply unit, and by alternating pressure increases and decreases, individual ABS is performed for each wheel via the second pressure supply unit (BM2), and / or During braking using the at least one traction motor, the braking torque generated by the second pressure supply unit (BM2) is distributed to each axle by controlling a special solenoid valve (MV2K) associated with the second pressure supply unit, and / or (Automatic) emergency braking is performed by driving and controlling the traction motors (TM1, TM2) and at least the first pressure supply unit (BM1) in parallel. It is structured in such a way. The driving dynamics system according to claim 1.

13. The electromagnetic drive device (EM1) is redundantly configured with at least one first solenoid valve driver and a second solenoid valve driver. The secondary control unit (S-ECU1) is communicatively connected to the first solenoid valve driver to control the at least one special solenoid valve (MV2k), and the primary control unit (M-ECU) is communicatively connected to the second solenoid valve driver to control the at least one special solenoid valve (MV2k). The driving dynamics system according to claim 1.

14. The primary control unit (M-ECU) is configured to at least temporarily adjust the braking pressure in the selection of the wheel brakes (RB1 to RB4) using the multiplex method and / or the PPC method. The driving dynamics system according to claim 1.

15. The primary control unit (M-ECU) is configured to perform at least the method described in claim 16. A driving dynamics system according to any one of claims 1 to 14.

16. Preferably, a method for adjusting the braking pressure in at least one wheel brake of a brake system via an inlet valve for introducing brake fluid into the wheel brake and an outlet valve for releasing brake fluid from the wheel brakes (RB1 to RB4), The said method, To determine that the pressure should be reduced from at least one of the aforementioned wheel brakes (RB1 to RB4), i.e., the target wheel brake, Selecting a decompression mode from the first decompression mode and the second decompression mode, When the first decompression mode is selected, in order to perform decompression, at least one of the outlet valves associated with the target wheel brake is opened, When the second depressurization mode is selected, the outflow valve associated with the target wheel brake is kept closed, at least one of the inflow valves associated with the target wheel brake is opened, and a pressure difference is formed in the (external) preferably second pressure supply unit in order to depressurize the target wheel brake through the inflow valve. Methods that include...

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