Driving power system of vehicle and method for adjusting brake pressure

Abstract

The invention relates to a driving power system for a vehicle having wheels (R1-R4), comprising: a main control unit (M-ECU) for detecting and / or generating steering and braking commands; at least two hydraulically actuatable wheel brakes (RB1-RB4), each wheel brake being associated with a respective one of the wheels (R1-R4); at least one electric traction motor having a traction motor control unit, the traction motors (TM1, TM2) for driving at least one of the wheels (R1-R4), the main control unit being communicatively connected to the traction motor control unit for controlling the traction motors (TM1, TM2) to execute steering and braking commands; and at least one (first) electro-hydraulic pressure supply unit (BM1), a brake pressure control valve in the form of a dedicated solenoid valve (MV2k), which valve can be closed in particular, and one of the outlet valves (AV1-AV4) being associated with at least one hydraulically actuatable wheel brake (RB1-RB4).

Description

[0001] This application is a divisional application. The parent application number is 202380059978.2, the application date is June 29, 2023, and the invention title is "A driving power system for a vehicle with wheels and a method for adjusting braking pressure". Technical Field

[0002] This invention relates to a driving dynamics system (FDS) having a main control unit or central computer and a method for adjusting braking pressure. Background Technology

[0003] Since the introduction of anti-lock braking systems (ABS), traction control systems (TCS), and electronic stability programs (ESP) in 1978, 1986, and 1995, respectively, brake pressure control systems based on the return principle of electrohydraulic brakes (EHB), which provide pre-pressure through the master brake cylinder, have matured. Here, pressure is increased by throttling via PWM at the inlet valve and decreased by time-controlled output valve. The valve block, motor, pump, accumulator chamber, eight solenoid valves (for ABS) or twelve solenoid valves (for ESP), pressure sensor, and electronic control unit (ECU) are typically integrated into a single unit, mounted separately from the brake booster (BB) in the engine compartment.

[0004] In existing vehicles on the market, the most common approach is to combine ABS / ESP pump units with vacuum brake boosters and vacuum pumps. So-called "dual-box" braking systems, featuring an electro-hydraulic brake booster and a spatially separated ESP unit (see German patent application DE102012211278A1), and so-called "single-box" braking systems, featuring an integrated brake booster and pressure regulation (see European patent EP1907253B1 and German patent application DE102013222281A1), are standard features in new vehicles.

[0005] Since its mass introduction in 1995, the hydraulic design of the ESP unit, with twelve solenoid valves as pressure supply units, has remained unchanged. However, a standardized interface (see VDA 360) has been specified for the interaction between the control unit of the electric brake booster and the control unit of the ESP unit to enable additional functions and component protection for the rigid electromechanical brake booster. For example, the solenoid valves of the ESP unit can be activated for specific functions via a control device. German patent application DE102012211278A1 describes the control of valves and the ABS pump for regenerative braking.

[0006] The automotive industry is undergoing a major transformation. In addition to the increasing market share of electric vehicles, it is currently experiencing different stages of autonomous driving (Levels 2 to 5 as defined by the Society of Automotive Engineers, i.e., SAE Levels 2-5). Each stage of autonomous driving increases the redundancy requirements of the braking systems used (see the article "Brake Boosters for Autonomous Driving" in the 3rd issue of Automotive Technology Magazine in 2019).

[0007] In addition, a central vehicle control system with a control unit (hereinafter referred to as "vehicle motion control" or "vehicle chassis control" (VCC)) for chassis control is introduced. This system includes electro-hydraulic brakes, electric traction motors™ on one or more axles of the vehicle, electric power steering (EPS), and optionally damping. Due to the central control system, synergistic effects can be utilized.

[0008] For the first time since 2020, regenerative braking in the Formula E racing series, which relies on a powerful electric traction motor, does not follow the standard "hybrid strategy" defined in the 5th edition of the Brakes Manual (see Chapter 19: "Regenerative Braking Systems"), in which hydraulic braking torque is reduced due to the braking torque of the electric traction motor. Instead, braking torque is additionally generated by the electric traction motor and electro-hydraulic brakes to reduce the time required to reach blocking braking torque / blocking braking pressure (TTL). This shortens braking distance by building up braking torque as quickly as possible.

[0009] Current limitations and problems of existing ABS / ESP systems One problem with current ABS / ESP braking systems with pump units is the limited power for new functions such as automatic emergency braking (AEB). For this function, it is crucial to raise the braking pressure to the wheel locking pressure (typically 80-100 bar in bus braking systems) in the shortest possible time. While ABS / ESP braking systems with pumps and electric brushed motors can reach 50 bar pressure in 450 milliseconds, single-box braking systems with powerful brushless motors (German patent DE102005063659B3) can reach 80-100 bar wheel locking pressure in less than 150 milliseconds. Shorter TTL times can mean a braking distance reduction of more than 5 meters at an initial speed of 65 km / h.

[0010] Every ABS / ESP braking system (including ABS / ESP systems with pump units and single-box brakes) in principle has a check valve. For safety reasons, the check valve is hydraulically connected in parallel with the inlet valve in the hydraulic line to the wheel brakes, ensuring that the pressure in the wheel brakes is always automatically reduced; that is, if the pressure supply fails, there is no pressure residue in the wheel brakes. However, this technical solution means that wheel brake circuit failures are difficult or even impossible to diagnose because it is unclear whether the check valve or the inlet valve is causing the wheel circuit failure. Therefore, in the event of a failure, the entire braking circuit with both wheel brakes must be deactivated. This is why the diagonal brake circuit layout (X-circuit) is the preferred layout in most vehicles, as braking can still be performed using the front wheel brakes, which have better braking performance than the rear wheel brakes, in the event of a brake circuit failure. The so-called "black / white" brake circuit distribution (II-circuit) is used in hybrid or electric vehicles. Its disadvantage is poor braking performance in failure situations, but its advantage is that the implementation of regenerative braking control strategies is simpler.

[0011] Furthermore, compared to the single-box braking system described above, which depressurizes by releasing pressure into a reservoir (see German patent application DE102013222281A1), the ABS / ESP braking system with a pump unit that depressurizes by releasing pressure into the accumulator chamber via a time-controlled outlet valve suffers from a disadvantage in braking distance control performance. This is because the back pressure (up to 5 bar) in the accumulator chamber during depressurization limits rapid depressurization under low pressure conditions. In the case of ABS control on roads with low friction coefficients (low-µ) (icy / snowy surfaces), this results in a slow pressure reduction, thus requiring a very long time for wheel speed to decrease during ABS control. This leads to a longer braking distance. In some cases, ABS can only provide basic control on roads with extremely low friction coefficients (icy surfaces). As a result, even under normal operating conditions, the standard ABS / ESP system exhibits a significant disadvantage in braking distance compared to the new standard set by single-box braking systems due to its poor control performance. Summary of the Invention

[0012] The object of this invention is to provide an improved driving power system, particularly in the form of multiple pressure supply units (a dual-box solution, i.e., two hydraulic supply units connected in series in two independent hydraulic supply units, each equipped with an independent pressure actuator for each wheel brake). Preferably, the system should solve the aforementioned problems. The system should be small, reliable, precise, safe, and efficient.

[0013] The driving power system should also meet the requirements of automated driving operation (SAE Level 3 or 4 automated driving by detecting driver requests via electronic pedals, or SAE Level 5 automated driving without pedals, with settings specified by the central computer), and should create new interfaces between the braking module or pressure supply unit and / or the braking module and the central computer.

[0014] In addition, the system should be able to effectively provide driving dynamic control functions (ABS, ESP, EBD, ACC, AEB, Recu-Mgt (Recuperation Management)) and wheel-specific braking torque intervention (Brake-to-Steer (BtS), Brake-to-Torque Vectoring (BtTV)) when integrated with at least one electric traction motor.

[0015] This objective is achieved by the subject matter of claim 1.

[0016] Specifically, this objective is achieved by a driving power system for a vehicle with wheels, the system comprising: The main control unit is used to detect and / or generate steering and braking commands; At least two hydraulically actuated wheel brakes, each wheel brake being associated with a single wheel; At least one electric traction motor having a traction motor control unit, wherein the traction motor is used to drive at least one of the wheels, and a main control unit is communicatively connected to the traction motor control unit to control the traction motor to execute steering and braking commands; At least one (first) electro-hydraulic pressure supply unit, comprising: At least one electric pump unit; At least two connection lines for connecting the wheel brakes; Electrically actuated wheel brake pressure regulating valve or brake pressure regulating valve; and First auxiliary control unit; In this embodiment, at least one hydraulically actuated wheel brake is associated with a brake pressure regulating valve and an outlet valve. The brake pressure regulating valve is a dedicated solenoid valve, which is particularly equipped with anti-passive closure characteristics. The driving power system, particularly the main control unit, is configured to selectively release the pressure of at least one hydraulically actuated wheel brake via an associated outlet valve or via a dedicated solenoid valve.

[0017] In the first variation, pressure reduction is preferably achieved solely through the corresponding outlet valve. In the second variation, pressure reduction can be achieved either through a dedicated solenoid valve alone or simultaneously through both a dedicated solenoid valve and the outlet valve.

[0018] Furthermore, this objective is achieved by a driving power system comprising: The main control unit is used to detect and / or generate steering and braking commands; At least two hydraulically actuated wheel brakes, each wheel brake being associated with a single wheel; At least one electric traction motor having a traction motor control unit, wherein the traction motor is configured to drive at least one of the wheels, wherein a main control unit is communicatively connected to the traction motor control unit to control the traction motor to execute steering and braking commands; At least one (first) electro-hydraulic pressure supply unit, comprising: At least one electric pump unit: At least two connection lines for connecting the wheel brakes; Electrically actuated wheel brake pressure regulating valve or brake pressure regulating valve; and First auxiliary control unit; At least one of the brake pressure regulating valves includes a dedicated solenoid valve with an electromagnetic drive device having a first excitation coil, which enables the valve actuator or valve tappet to be adjusted between the valve open position and the valve closed position.

[0019] One aspect of the invention is that the dedicated solenoid valve has an additional force device comprising a permanent magnet and / or a second excitation coil, and the additional force device is used to provide at least one holding force acting on the valve actuator or valve tappet. Preferably, the dedicated solenoid valve, which can be used as an inlet valve or a wheel inlet control valve, has an anti-passive shut-off feature in this embodiment.

[0020] Due to its wheel brake circuit design with a wheel inlet control valve that prevents passive closure, the system of this invention offers significantly higher fail-safety than prior art braking systems and can replace conventional braking circuits with multiple wheels (diagonal or black-and-white braking) with a braking system featuring wheel circuits (for wheel pressure control and / or supply). For example, wheel circuit failures can be diagnosed, and the faulty wheel circuit can be disconnected from the pressure supply by closing the inlet valve. This means that if one (individual) wheel circuit fails, significantly improved deceleration can be achieved using the remaining three wheel circuits in the event of the failure, and yaw moment intervention can still be performed on all three wheels. Hereinafter, the braking module with a first pressure supply unit featuring a dedicated solenoid valve according to claim 1 is referred to as ESP-X.

[0021] For example, the main control unit can detect steering and / or braking commands via steering wheel sensors or force / displacement sensors on the electric brake pedal. However, the main control unit can also be used to generate independent steering and braking commands. This is necessary during autonomous driving. Corresponding commands can also be generated due to the implementation of safety functions such as automatic emergency braking (AEB). The steering commands of this invention are not limited to specific driver intervention via the steering wheel. Rather, this invention interprets steering commands as any instruction related to the movement of the vehicle in a specific direction, and also includes trajectory control in autonomous driving mode. For example, this includes commands that cause changes in yaw torque. Torque vectors can also be implemented using corresponding steering and / or braking commands.

[0022] (First) The electro-hydraulic pressure supply device can be an ABS / ESP unit. However, this should generally be understood to refer to any unit with a pressure generator, such as a unit with a pressure generator in the form of the aforementioned pump unit, which provides the corresponding pressure at the corresponding connection points. The pressure supply unit can also perform regulation and / or control functions. Therefore, it can also be a pressure control module.

[0023] One aspect of the invention is that a dedicated solenoid valve provides additional holding force. Therefore, the dedicated solenoid valve has anti-passive-closing characteristics and can release high pressure through this valve. In addition to the retaining force, the dedicated solenoid valve can also provide a restoring force to move the valve actuator or valve tappet to the valve open position.

[0024] In one embodiment, the main control unit can be used to control dedicated solenoid valves of the first pressure supply unit, at least in selected braking modes, such that when a dedicated solenoid valve opens, pressure in the wheel brakes assigned to that dedicated solenoid valve is released. Preferably, each dedicated solenoid valve of the first pressure supply unit is assigned to a wheel brake. Due to its anti-passive-closing design, the corresponding dedicated solenoid valve can be used not only as an inlet valve but also as an outlet valve. Pressure can be increased and released bidirectionally through the same dedicated solenoid valve. This allows the assigned wheel brakes to depressurize (significantly) quickly, as pressure can be released via several valves (dedicated valves) as well as via the outlet valve. Furthermore, when the pressure in the wheel brake is high while the pressure generator is operating at low pressure, the pressure in the wheel brake can be maintained by closing the valve. This provides new degrees of freedom, which is highly advantageous in a central control strategy employing a main control unit.

[0025] In one embodiment, at least one of the wheel brakes associated with the dedicated solenoid 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 dedicated solenoid valve are used simultaneously to reduce pressure in the corresponding wheel brake as quickly and efficiently as possible. Specifically, the main control unit can be configured to control the associated dedicated solenoid valve and the outlet valve, at least in selected braking modes, such that brake fluid is simultaneously discharged from the wheel brakes via both the associated dedicated solenoid valve and the associated outlet valve.

[0026] In one embodiment, the driving power system has at least one second pressure supply unit. Preferably, this unit comprises a piston-cylinder unit or a rotary pump, i.e., a separate pressure generator. The second pressure supply unit may be connected to at least one input of the first pressure supply unit to supply brake fluid. In one embodiment, the pressure supply unit functions not only as an accumulator but also as a (controllable / adjustable) pressure trap (pressure reduction device) or alternatively has at least one valve for reducing pressure (e.g., a central outlet valve, see WO2020165259A1, the outlet valve of the ABS / ESP unit). Pressure reduction (pressure reduction) can be time-controlled by the valve, but PWM control can also be used if the inlet valve of the ABS / ESP unit is used for pressure reduction. For example, if a piston-cylinder unit is used, very low pressures, such as 1 to 5 bar, can be generated by retracting the cylinder into the piston, where the existing pressure difference causes a rapid decrease in pressure in the wheel brakes. In a (preferred) embodiment, the pressure supply unit supplies brake fluid to the first and second braking circuits, wherein preferably, at least one isolation valve is provided for isolating the first and / or second braking circuits. As explained in more detail below, the isolation valve can be designed similarly or identically to the dedicated solenoid valve already described.

[0027] Multiple first pressure supply units can also be set up and connected to a second pressure supply unit.

[0028] In one embodiment, a first pressure supply unit is directly connected to exactly two wheel brakes. Preferably, these two wheel brakes are associated with wheels located on a first axle. In one embodiment, in addition to the first pressure supply unit, at least one additional pressure supply unit is provided, which is directly connected to at least two wheel brakes on a second axle. In other words, the additional pressure supply unit supplies the two wheel brakes associated with the wheels located on the second axle. According to the invention, multiple first pressure supply units can therefore be configured as different modules, each module being associated with a specific axle or wheel brakes on a specific axle. Depending on the vehicle, in addition to the first and second axles, additional axles with additional pressure supply units may be provided, wherein each pressure supply unit on the axle is preferably communicatively connected to a main control unit for receiving steering and braking commands. According to the invention, a direct connection between one device and another can be understood as providing a hydraulic connection, for example, via a pipeline, which is not interrupted by other devices such as valves or pressure generators.

[0029] In one embodiment (hereinafter also referred to as valve connection variant I), a dedicated solenoid valve is connected to the wheel brake via the valve's armature chamber, while its seat is connected to the pressure supply unit. This is common in prior art ABS / ESP systems, and the solenoid valve is designed to be open when power is off. Pressure can be built up (increased) by pre-pressure control and PWM control of one or more dedicated solenoid valves. Pressure release (depressurization) is achieved by time-controlled operation of the same valve. Due to its anti-passive-closing design, there is no risk of the dedicated solenoid valve being passively closed during pressure reduction.

[0030] In one (other) embodiment (valve connection variant II), the seat of at least one dedicated solenoid valve is connected to the wheel brake. This arrangement allows for a smooth release of pressure in the corresponding wheel brake. Thanks to this configuration, the valve opening cross-section can be adjusted, particularly via PWM control or current control. This enables throttling and pressure reduction via the dedicated solenoid valve. In this embodiment, pressure increase via the dedicated solenoid valve can be achieved through time control or volume measurement, which can be performed in a second pressure supply unit, for example, by adjusting the rotation angle of the rotary pump or the piston stroke of the piston-cylinder unit.

[0031] Both types of connections can be closed simply by energizing a dedicated solenoid valve, thus disconnecting the wheel brake from the system. A lower holding current can also be applied to keep the dedicated solenoid valve closed. Disconnection may be advantageous if a defect such as leakage has been detected in the corresponding wheel brake.

[0032] In one embodiment, the first supply unit may include a rotary pump connected to the wheel brake and configured to increase and decrease pressure in the wheel brake. Thus, the rotary pump can act as a pressure trap and enable rapid depressurization.

[0033] Furthermore, this objective is achieved by a driving power system comprising: The main control unit is used to detect and / or generate steering and braking commands; Four hydraulically actuated wheel brakes, each wheel brake is associated with a wheel; At least one electric traction motor having a traction motor control unit, wherein the traction motor is configured to drive at least one of the wheels of a vehicle, wherein a main control unit is communicatively connected to the traction motor control unit to control the traction motor to execute steering and braking commands. At least one first electro-hydraulic pressure supply unit includes: At least one electric pump unit; At least two connection lines for connecting the wheel brakes; Electrically actuated wheel brake pressure regulating valve or brake pressure regulating valve; and First auxiliary control unit; At least one second electro-hydraulic pressure supply unit is configured to supply brake fluid to a first brake circuit and a second brake circuit at at least one inlet of the first pressure supply unit; At least one isolation valve in the form of a dedicated solenoid valve is assigned to the second pressure supply unit, and the isolation valve is used to isolate the first and / or second braking circuits; The dedicated solenoid valve includes an electromagnetic drive device with a first excitation coil. The valve actuator or valve tappet of the dedicated solenoid valve can be adjusted between the valve open position and the valve closed position via the first excitation coil.

[0034] Alternatively, this objective can be achieved through a system for vehicles with wheels, particularly a driving power system, especially as described in the previous embodiments. This system may include: The main control unit is used to detect and / or generate steering and braking commands; Four hydraulically actuated wheel brakes, wherein each wheel brake is associated with one of the wheels; At least one electric traction motor having a traction motor control unit, wherein the traction motor is used to drive at least one of the wheels of a vehicle, wherein a main control unit is communicatively connected to the traction motor control unit to control the traction motor to execute steering and braking commands. At least one first electro-hydraulic pressure supply unit includes: At least one electric pump unit; At least two connection lines for connecting the wheel brakes; Electrically actuated wheel brake pressure regulating valve or brake pressure regulating valve; and First auxiliary control unit; At least one second electro-hydraulic pressure supply unit is configured to supply brake fluid to the first brake circuit and the second brake circuit at at least one inlet of the first pressure supply unit; At least one isolation valve, which is in the form of a dedicated solenoid valve, is used to isolate the first and / or second braking circuit; The dedicated solenoid valve includes an electromagnetic drive device with a first excitation coil. The valve actuator or valve tappet of the dedicated solenoid valve can be adjusted between the valve open position and the valve closed position via the first excitation coil.

[0035] The system is characterized in that the dedicated solenoid valve is resistant to passive closure, particularly by providing an additional force device comprising a permanent magnet and / or a second excitation coil, and the additional force device being configured to provide at least one retaining force acting on the valve actuator or valve tappet.

[0036] One aspect of the invention is that the dedicated solenoid valve has a passive shut-off prevention function, particularly by providing an additional force device comprising a permanent magnet and / or a second excitation coil, and the additional force device being configured to provide at least one holding force acting on the valve actuator or valve tappet.

[0037] Therefore, a dedicated solenoid valve can also be used as an isolation valve, for example, as part of a second pressure supply unit (hereinafter also referred to as a second braking module), wherein the second braking module need not include an isolation valve if there is only one hydraulic connection with the first braking module. Figure 9 , Figure 10 , Figure 15 This is also referred to as a braking module in embodiments without an isolation valve. The anti-passive-closing feature also leads to a significant improvement in the system. Typically, other valves with corresponding anti-passive-closing features can also be used according to the invention. The system is preferably a dual-box system, wherein a first pressure supply unit is part of a first box and a second pressure supply unit is part of a second box.

[0038] If a dedicated solenoid valve with the aforementioned permanent magnet and / or second excitation coil is used, it can be designed similarly or identically to the one described above. The additional force device can also generate an additional restoring force in addition to the aforementioned holding force.

[0039] By advantageously using a second pressure supply unit to reduce pressure to a low coefficient of friction, even low-cost ABS / ESP braking systems can achieve a new level of control quality and compete with new single-box braking systems in terms of braking distance performance (German patent application DE102013222281A1, Brake Manual 5th Edition, Chapter 20.3 "Integrated Braking System MK C1").

[0040] Regardless of the design of the second pressure supply unit, in one embodiment, the first pressure supply unit can be equipped with a rotary pump that can increase and decrease pressure depending on the direction of rotation, providing further flexibility for pressure reduction. Furthermore, in this embodiment, since there is no back pressure in the accumulator chamber, the pressure can be easily reduced when the ABS operates under low friction coefficient (“low-μ”) conditions. This results in a high-precision and cost-effective system.

[0041] In a further embodiment, the first pressure supply unit can be designed to provide a pressure reduction to the reservoir rather than the accumulator chamber. This is possible because the dedicated solenoid valve according to the invention (especially when used as an inlet valve) provides a high safety gain and significantly improves ABS control performance.

[0042] In one embodiment, braking torque is simultaneously established on one or more axles by means of the pressure from the electric traction motor and the first and / or second pressure supply unit. In this case, electric brake force distribution (EBD) can be performed during the pressure rise by means of the first and / or second pressure supply unit to prevent the rear wheels from locking / locking before the front wheels. If wheel lock-up pressure is reached, ABS control can be activated according to the invention, and the braking torque of at least one traction motor will be rapidly reduced. For electric traction motors operating at high voltages (greater than 400 volts (V), especially greater than 700 V) and having a braking torque gradient greater than 10,000 Nm / s, the corresponding operating procedure does not pose a safety risk and is fast enough to achieve a safe reduction in braking torque, if necessary, within the first control cycle. According to the invention, this can be achieved by introducing a central vehicle dynamics control (FDS) that synchronizes the electric traction motor TM and the pressure generator unit, and allows for rapid detection of ABS conditions by evaluating wheel speed sensors. To this end, the main control unit can be communicatively connected to the wheel speed sensors, allowing direct reading of the corresponding sensor values. According to the method of the present invention, in automatic emergency braking where pressure is generated solely by the pump of the first braking module BM1, a TTL of 150 ms can be achieved, whereas previously only single-box braking systems equipped with powerful brushless motors could achieve a comparable value.

[0043] Alternatively or additionally, in addition to the electric traction motor, a 6-piston pump or a more powerful brushed motor can also be used in the first pressure supply unit of the present invention, thereby achieving a shorter TTL time. Using this method, a good TTL time, possibly in the range of 150 ms, can also be achieved with a less powerful electric traction motor. According to the present invention, various technical solutions can be combined differently within a modular concept.

[0044] The pressure supply unit can be configured to increase and decrease pressure. Each of the first and second pressure supply units has an auxiliary control unit, and each auxiliary control unit has at least one communication interface. These communication interfaces can be used to establish communication with the main control unit. In particular, measurement signals and control setpoints can be exchanged. The dedicated solenoid valve of the second pressure supply unit can be arranged such that the valve seat of the dedicated solenoid valve is (directly) connected to the input of the first pressure supply unit (valve connection variant III). Due to the arrangement of the dedicated solenoid valve, the valve opening cross-section can be adjusted, particularly by means of PWM control or current control. In this case, this special arrangement also means that the pressure of the first pressure supply unit can be throttled and regulated by the dedicated solenoid valve, thereby achieving low-noise pressure reduction. In this arrangement, the pressure is preferably increased by time control or volume measurement (see the explanation above regarding pressure control / regulation by volume measurement).

[0045] In one embodiment, the main control unit is configured to achieve pressure control for the wheel brake or for the brake circuit by activating at least one of the dedicated solenoid valves of the first pressure supply unit and / or at least one of the dedicated solenoid valves of the second pressure supply unit.

[0046] In one embodiment, the main control unit is configured to detect a wheel circuit fault by measuring pressure when a dedicated solenoid valve or inlet valve of the first pressure supply unit is closed. The corresponding diagnostic procedure may include measuring whether the pressure in the system drops with all relevant valves closed. If so, a leak can be assumed. By closing the dedicated solenoid valve, pressure can still be built up in the remaining brake circuit or other leak-free wheel circuits. For example, a second pressure supply unit can increase the pressure by piston movement.

[0047] If there is no increase in pressure associated with piston movement, then a leak can also be concluded in this case.

[0048] As already explained, the main control unit can be configured to isolate a faulty brake circuit by closing at least one of the isolation valves. Therefore, in some embodiments, a circuit breaker for the wheel circuit or for the brake circuit can be isolated to isolate the faulty brake circuit or wheel brake circuit while maintaining the functionality of the rest of the system.

[0049] The main control unit can be configured to implement (axle-dependent) ABS by controlling at least one of the isolation valves and performing pressure build-up and pressure reduction (alternatingly) via a second pressure supply unit. Unlike conventional systems, the second pressure supply unit can therefore also be used to implement at least (basic) single-channel ABS. This results in additional redundancy.

[0050] In one embodiment, the main control unit is configured to achieve (automatic) emergency braking by actuating a traction motor and at least a first pressure supply unit in parallel. Alternatively, the corresponding control strategy can be implemented using only a single traction motor.

[0051] The main control unit can be configured to achieve (automatic) emergency braking (AEB) or brake torque build-up by controlling the electric traction motor and electro-hydraulic brakes, especially to achieve higher braking torque (vehicle deceleration > 3 m / s²). 2 When emergency braking is applied, the braking torques of the electric traction motor and the first pressure supply unit will be superimposed until a high deceleration (>5m / s²) is achieved. 2 Preferably until the maximum deceleration (>8m / s) 2 Especially >9.5 m / s 2 During emergency braking, i.e., during the period of high dynamic pressure build-up, the ABS status can be detected by evaluating the wheel speed sensors. In this case, the main control unit can reduce the braking torque of the electric traction motors and / or electro-hydraulic brakes (central) on one or more locked wheels, or the braking torque of the axle.

[0052] In one embodiment, the first electromagnetic drive device employs a redundant design, equipped with at least one first solenoid valve driver and one second solenoid valve driver. An auxiliary control unit for controlling the at least one dedicated solenoid valve is communicatively connected to the first solenoid valve driver, and a main control unit for controlling the at least one dedicated solenoid valve is communicatively connected to the second solenoid valve driver. This means that the dedicated solenoid valve can be actuated by two independent control units, ensuring continued actuation of the dedicated solenoid valve even if one control unit fails. The communication connection can be an electrical connection.

[0053] In one embodiment, the main control unit is configured to, at least auxiliaryly, set the braking pressure for at least one selected wheel brake via a multiplexing / PPC process, wherein the main control unit sends a control signal to a second pressure supply unit to establish or reduce the pressure.

[0054] In one embodiment, a new FDS architecture is created, which has a communication interface Int between a central computer or main control unit and the control unit of the braking module. BM1 Int BM2 Furthermore, in the case of multiple braking modules, there is another interface Int between the control units of two braking modules. 2BM Int 2BMThe interface is based on the VDA360 guideline, which defines the interaction between electric regenerative braking boosters (such as i-booster products) and ESP-HEV braking systems for energy recovery braking (including the interface for valve actuation of the ESP-HEV system outlet valve). Furthermore, at least one electric traction motor is integrated into the FDS. At least one additional interface is provided between the central computer and the traction motor, preferably an IntTM interface between the main control unit and the auxiliary control unit of the corresponding traction motor. i Interface, or in the main control unit and vehicle (IntTM) HA IntTM VA This provides an interface between the control units of the corresponding axles, especially when the axles are equipped with several traction motors. For example, this configuration is advantageous if a traction motor is provided for each wheel on the rear axle to accelerate or brake the wheel individually.

[0055] One or more of the communication interfaces can be electrical, wireless, or optical connections, with two communication paths preferably selected. The first communication path can be redundant, and the second communication path can be used to check the signal of the first communication path. In one embodiment, two different signal transmission types are used to implement the "two-out-of-three rule," ensuring compliance with SAE Level 5 standards and eliminating errors during transmission. The "two-out-of-three rule" is mandatory for SAE Level 4 braking systems with electric pedals or SAE Level 5 braking systems without pedals, as there is no longer a brake pedal accessible to the driver.

[0056] Furthermore, the main control unit can also control the solenoid valve actuator of the inlet valve of the first pressure supply unit. This means that regardless of the operational capabilities of the pressure generator (e.g., a pump) and the auxiliary control unit of the first pressure supply unit, only the dedicated solenoid valves on the second pressure supply unit and the wheel brakes are available for wheel-specific pressure control, particularly for implementing 4-channel ABS or wheel-specific braking torque intervention for steering functions. In one embodiment, the solenoid valve actuator, especially the dedicated solenoid valve, is designed to be redundant.

[0057] In one embodiment, the auxiliary control unit of the first pressure supply unit is equipped with solenoid valve electronics that are electrically isolated from the main control board, which has its own independent power supply voltage and can therefore operate independently. In this way, fully functional ABS can be achieved even in the event of a complete failure of the first pressure supply unit.

[0058] Furthermore, the implementation of central vehicle power control in the domain of a central computer with chassis control can be simplified by integrating steering actuators (e.g., electric power steering and electric traction motor). Existing software architecture can be largely preserved, and additional overall functions requiring interaction between the steering actuator and electric traction motor can be easily implemented, for example, in the main control unit. In one embodiment, the function of the first pressure supply unit is transferred to the main control unit, such that the first pressure supply unit is designed solely as a pressure actuator.

[0059] As a central vehicle power control system for vehicles, the driving power system (FDS) may include several components listed below: The main control unit is used to detect and / or generate steering and braking commands; Among them, at least one of the following functions in the main control unit—ABS, ESP, TCS, ACC, AEB, energy recovery braking, and steering—has redundant microcontrollers μC1, μC2, and μC3. At least one electric traction motor for driving and braking the wheels, each electric traction motor being equipped with an auxiliary control unit or vehicle axle control unit; At least one braking module is hydraulically connected to multiple wheel brakes; The central vehicle model enables the calculation of steering and braking commands, taking into account the road surface friction coefficient, vehicle speed, and / or the dynamic weight distribution of the vehicle during braking.

[0060] In this system, data from at least the wheel speed sensor and preferably other sensors (accelerometer and / or weight sensor) are read into the main control unit for braking and steering.

[0061] The driving dynamics system FDS is characterized in that the main control unit sends steering and braking commands for braking torque modulation (e.g., ABS, ESP, EBD) to several auxiliary control units in the following manner: An electric traction motor or a first or second braking module provides the basic braking torque, and the braking torque modulation (e.g., ABS, ESP) is controlled via the electric traction motor; Alternatively, the braking torque modulation may be jointly controlled by at least one electric traction motor and at least one braking module; Alternatively, the braking torque modulation on the rear axle can be controlled by an electric traction motor, while the braking torque modulation on the front axle can be controlled by at least one electro-hydraulic braking module.

[0062] The advantages of FDS can be fully utilized to optimize the braking unit based on braking conditions (comfort braking, emergency braking), road conditions (braking on asphalt, snow, ice, sudden changes in friction coefficient μ, and m-separation braking), and the availability of braking modules. This maximizes regenerative braking control performance under various driving conditions. Furthermore, FDS control and regenerative braking via the electric traction motor should reduce the cost of brake calipers, even at high decelerations of <5 m / s. Regenerative braking minimizes the thermal load on friction brakes and allows for a reduction in the size of disc brakes on the front axle or the use of drum brakes on the rear axle.

[0063] During braking torque modulation, at least one braking module and at least one electric traction motor are simultaneously controlled via the central main control unit, and braking torque commands are assigned to at least one braking module and at least one electric traction motor.

[0064] By designing the braking system using at least one braking module and a dedicated solenoid valve, preferably directly controllable by the main control unit, specific braking torque intervention for each wheel can be implemented with the aid of the main control unit. According to the invention, if a wheel circuit fails, the remaining wheel circuits can continue operating by closing the dedicated valve of the failed wheel's braking circuit. Furthermore, the TTL time can be minimized via central control of at least one traction motor and at least one braking module.

[0065] The following features particularly benefit from this embodiment: High-dynamic (50-180ms) automatic emergency braking (AEB) is achieved through the combined braking torque intervention of the electric traction motor and the braking module. Wheel-directed braking torque intervention for steering assist (Brake to Steer (BtS)) or drive dynamics (Brake to Torque Vectoring (BtTV)); Vehicle stability at high yaw speeds (ESP function); Regenerative braking for wheels or axles.

[0066] According to the present invention, new functions and improved reliability can be achieved by improving the hydraulic structure and replacing fewer components on the basis of a dual-circuit ABS / ESP braking system. This results in a three-circuit or four-circuit braking system with significant safety advantages. The Drive Dynamics System (FDS) can also provide wheel-specific braking torque control via the pressure interface Int-BM1 between the system and the main control unit. Wheel-specific or axle-specific braking torque control via this pressure interface is easier to achieve than using a standard ESP unit. The system according to the present invention can also more precisely and dynamically adjust the pressure in each wheel brake. With the system of the present invention, wheel-specific braking torque intervention can always be applied to all three wheel brakes, which brings significant advantages in vehicle stability functions and high-dynamic processes such as AEB with electronic brake force distribution (EBD).

[0067] The driving dynamics system also meets the redundancy requirements of SAE Level 3-5 automated driving (redundant brake assist, redundant ABS, and EBD functions). The system can operate with two pressure supply units (i.e., a dual-box braking system with one pressure supply unit on each side). This significantly improves control performance under low friction coefficient (low-μ) conditions compared to existing technologies, in addition to redundant ABS / ESP functions, through the interaction of the ESP-X unit with the external pressure generator DV2 (especially as part of the pressure supply unit). Integrating this advantageously into the electric vehicle domain architecture of a central computer presented as a main control unit aims to improve emergency braking (AEB) by synchronously setting the setpoint parameters of the braking torque to the control units of one or more electric traction motors. This significantly reduces TTL time.

[0068] Because the braking torque of the electric traction motor either acts on only one axle or on multiple axles with varying braking torques, brake force distribution (EBD) must also be controlled. That is, the hydraulic braking torque must be distributed to the front and rear axles differently compared to a standard EBD control system. The system according to the invention prevents the rear axle wheels from locking / locking before the front axle wheels, and the front axle wheels can only lock when the deceleration reaches 0.85g. In the event of wheel lockup, ABS intervenes, and the braking torque of the electric traction motor must be taken into account in ABS control.

[0069] An embodiment of the driving power system according to the invention is characterized in that at least two, preferably four, inlet valves of the first pressure supply unit are replaced by dedicated solenoid valves, which are open when there is no current. Compared to the prior art, the dedicated solenoid valves preventing passive shut-off do not have check valves arranged in a hydraulic path parallel to the inlet valves or integrated into the inlet valves. As explained in the problem definition of the prior art, the function of a check valve is to ensure a safer reduction of the braking pressure of the wheel brakes even in the event of a failure or partial failure of the braking system (e.g., the pressure supply unit). However, in the system of the present invention, the check valves can be omitted.

[0070] The aforementioned objective is also achieved through a switching valve. This switching valve can be used in conjunction with the driving power system already described. It can function as both an inlet valve (for the ESP system) and an isolation valve for the second pressure supply unit.

[0071] The switching valve may include: Valve actuator or valve tappet; An armature, which is connected to a valve actuator or valve tappet; An electromagnetic drive device having at least one excitation coil for adjusting the valve tappet along the longitudinal direction between the valve open position and the valve closed position.

[0072] The switching valve is characterized in that the armature includes at least one permanent magnet. In one embodiment, this is arranged such that the valve actuator or valve tappet is held in the open position by means of the magnetic force generated by the permanent magnet. Preferably, this magnetic force is also active when the electromagnetic drive is not energized. This gives the switching valve a particularly high resilience in the face of passive closure, especially when a large flow of fluid passes through the valve.

[0073] The switching valve described above, as well as the various embodiments of the switching valve explained below, can all be used as dedicated solenoid valves within the scope of this invention.

[0074] In one embodiment, at least one or more toroidal permanent magnets are disposed in the armature. The magnetic poles of the toroidal magnets or the multiple permanent magnets are substantially perpendicular to the longitudinal direction.

[0075] In one embodiment, a ring-shaped permanent magnet or multiple permanent magnets are embedded in a material with ferromagnetic conductivity in both the axial and radial directions.

[0076] In one embodiment, the permanent magnet (PM) and / or the adjacent ferromagnetic flux guide are arranged and sized as follows: when the electromagnetic actuator is de-energized, the magnetic force moves the valve pusher from the valve closed position to the valve open position. Therefore, this is a power-off opening valve that automatically opens in the event of a power outage. This has particular advantages, especially when combined with the aforementioned driving power system.

[0077] The electromagnetic drive may include a first excitation coil and at least one second excitation coil. Therefore, redundant excitation coils exist, which are preferably connected to a separately designed solenoid valve actuator. This generally increases the reliability of the valve. Furthermore, the valve can be connected to different control units, for example, to one auxiliary control unit and one main control unit. This means that if one control unit fails, the other control unit can take over control of the valve.

[0078] In one embodiment, an H-bridge with four switches, particularly power semiconductors, is provided. This H-bridge can generate electromagnetic fields with different polarizations, allowing a valve to actively close and open when the excitation coil is energized, depending on the wiring of the H-bridge and the resulting direction of the current through the excitation coil. Furthermore, during pressurization and depressurization, the valve can operate independently of the fluid flow direction through variable cross-section current control. The H-bridge can reverse the electromagnetic field in at least one excitation coil and can also adjust the magnetic field strength. This allows for the adjustment of the force acting on the armature (along the effective direction) and its magnitude.

[0079] In an (alternative) embodiment, the switching valve advantageously provides a novel and cost-effective design that is also in accordance with the invention, having a first soft ferromagnetic circuit EM1 and a second magnetic circuit EM2 generated by a permanent magnet. In one embodiment, the forces of these two magnetic circuits EM1 and EM2 act on the armature of the ball-seat switching valve.

[0080] By using most of the components of a standard solenoid valve (such as the armature diameter and the magnetic circuit with the coil) and modifying only the end (head) of the valve, some of the switching valves in this invention can be manufactured at a lower cost.

[0081] The valve head is equipped with a permanent magnet circuit, meaning that the dedicated solenoid valve combines a soft ferromagnetic circuit and a second magnetic circuit generated by a simple permanent magnet into a single valve. This embodiment has the significant advantage of being able to be manufactured using existing production facilities. The inlet valve, preferably having a constant diameter and the same interface as the hydraulic block (HCU), can be easily replaced by a dedicated solenoid valve using typical press-fit assembly techniques; that is, the dedicated solenoid valve can be easily inserted into the unmodified hydraulic block. Furthermore, the auxiliary control unit (ECU), mounted on the hydraulic block and carrying the excitation coil of the solenoid valve, requires no modification or only minor alterations.

[0082] Typically, the (first) braking module with the aforementioned dedicated solenoid valve can be used in the following configurations (AE): A) Configuration A: Braking module (e.g., as a dedicated solenoid valve), hydraulically connected to the vacuum brake booster; B) Configuration B: Braking module, hydraulically connected to an electric brake booster, such as that described in German patent application DE112009004636B4; C) Configuration C: Braking module, hydraulically connected to an electro-hydraulic brake booster with a pedal feel simulator; D) Configuration D: Braking module, hydraulically connected to the second braking module BM2 and controlled via the main control unit and electronic brake pedal; E) Configuration E: The braking module is controlled as an independent pressure control unit via the main control unit, for example as an axle module for actuating the brakes of two wheels or a central hydraulic device for actuating the brakes of four wheels.

[0083] All AE configurations can be achieved using a dedicated valve with anti-passive shut-off function (the wheel brake circuit can be disconnected by closing a dedicated solenoid valve). Leakage diagnosis is performed by measuring the pressure rise or volumetric flow rate during the pressure increase process when the valve is closed using a pressure supply unit. Wheel brake circuit faults are diagnosed by measuring the pressure rise or volumetric flow rate when the valve is open and comparing it with a previously measured typical pressure-volume characteristic curve of the wheel circuit stored in memory. This determines whether the wheel brake circuit should continue to operate even in the presence of a minor leak; The decision was made to disconnect the brake circuit by permanently closing the valve connected to the faulty wheel brake circuit, and to continue operation relying on the three wheel brake circuits; Pressure can be selectively reduced using an outlet valve or a dedicated solenoid valve; In other wheel brakes, the wheel braking pressure is kept at a low braking pressure level.

[0084] Furthermore, if, for example, the excitation coil or solenoid valve actuator of the normally closed outlet valve fails, the pressure can be reduced via the inlet valve instead, which improves the availability of the driving power system FDS.

[0085] Because this dedicated solenoid valve is particularly important for both function and safety, it would be highly advantageous if it possessed redundant coils and solenoid valve actuators, in addition to an anti-passive-closing design. In the case of a normally closed outlet valve, this redundancy can be omitted for cost reasons, as pressure can still be reduced via the dedicated solenoid valve even if the outlet valve fails. This ensures redundant pressurization functionality and significantly reduces the likelihood of wheel braking circuit failures, allowing the driving dynamics system to operate with high reliability using all wheel braking circuit channels. Redundancy is especially important in cases of specific braking torque control for each wheel, particularly when central vehicle power control is implemented via the main control unit, such as for BtS and BtTV functions.

[0086] In one embodiment of the invention, the known pressure control method can remain unchanged, while the pressure increase is achieved through pre-pressure control and operation of an inlet valve having a variable valve opening cross-section. The solenoid valve is operated by current control or as a proportional valve (referred to in the art as PWM operation of the inlet valve).

[0087] In a further embodiment, the new degrees of freedom in the control strategy can be used for pressure control. This improves the functionality of ABS operation and enables new functions, such as wheel-specific braking torque intervention via a pressure interface with a central computer. New functions of the central vehicle dynamics control include, in particular, wheel-specific braking torque control for torque vectoring (BtTV), braking torque intervention for ESP or steering (BtS) functions, and / or yaw rate control for axle-specific or wheel-specific regenerative braking.

[0088] In one embodiment (valve connection variant I), the seat of the inlet valve, particularly a dedicated solenoid valve, is connected to the brake circuit, and the armature chamber is connected to the wheel brake. Pressure control method A is used here (e.g., standard pressure setting mode or EV). PWM / AV Δt - Pressure control method), namely the traditional pressure control method, which uses PWM control on the inlet valve during pressure rise and time control on the outlet valve during pressure fall (Figure 20.12.a in the brake manual).

[0089] Alternatively, due to the use of an inlet valve designed to prevent passive closure, pressure control method B (multiplexing / PPC control method, hereinafter also referred to as "dedicated pressure setting mode I") can also be used in conjunction with variant I. As shown in Chapter 20.4, "Integrated Brake System (IBS)," of the fifth edition of the Brake Manual—Figure 20.13, the multiplexing / PPC method has significant advantages in ABS control on low-friction surfaces because the pressure reduction gradient via the piston-cylinder unit is not limited by the accumulator chamber back pressure, thus enabling a smaller reduction in wheel speed when a wheel locks up. The inlet valve designed to prevent passive closure, especially in the form of a dedicated solenoid valve, is used in the same manner as the switching valve shown in Figure 20.12.b of the Brake Manual. Another pressure supply unit, such as a second pressure supply unit, is advantageously used as both a pressure source and a pressure trap. The second pressure supply unit may include a piston-cylinder unit or a rotary pump, wherein the piston of the piston-cylinder unit advances during pressure increase and retracts during pressure decrease, or the rotation direction of the pump motor of the rotary pump is such that the pressure increases (p... auf ) and pressure reduction (p ab (Changes during the period)

[0090] For pressure control and the use of the piston-cylinder unit according to pressure control method B, the well-known "piston pressure control" (PPC) method can be employed. This method allows for highly dynamic pressure increase and decrease through the use of sensor signal current, piston position, and pressure-volume characteristic curves. This method can also be used to precisely control the pressure curve over time. The inlet valve remains open during pressure changes, and the pressure curve is preferably controlled solely by volume control via the piston-cylinder unit (through controller cascading with piston stroke, piston speed, and motor current) or by (current-proportional pressure control). During pressure increases, the inlet valve can use a multiplexing / PPC method (Pressure Control Method B: p auf / p ab Multiplexing / PPC method) and PWM control (p auf EV PWM ;p ab (1): EV Δt p ab (2): AV Δt The pressure control method allows for time-based control or sequential throttling control. This means that the driving power system of the present invention can be used to simultaneously set different braking pressures on different wheel brakes with high precision.

[0091] In one embodiment, switching can be made between pressure control method A (standard pressure setting mode) and pressure control method B (dedicated pressure setting mode I) during operation. Preferably, the switching between pressure control methods is such that pressure control method A is used for ABS pressure control on asphalt roads (high-μ) or in cases of abrupt changes in the coefficient of friction (μ-abrupt changes), where high pressure changes must be achieved simultaneously on multiple wheel brakes. Pressure control method B is preferably used in cases of low coefficient of friction, such as on snow / icy roads (low-μ). The main control unit is preferably designed to detect different conditions. In one embodiment, if the main control unit is configured accordingly, one braking circuit of the driving power system can operate using pressure control method A, while a second braking circuit can operate using pressure control method B.

[0092] In another embodiment (valve connection variant II), a dedicated solenoid valve with a valve seat is connected to the wheel brake, thereby reducing pressure in a throttle manner through a variable valve opening cross-section. In this embodiment, a second pressure supply unit can be used to simultaneously or sequentially increase the pressure, preferably by moving a piston and controlling it via time (rather than using multiplexing / PPC methods for PWM operation). In this embodiment, the control / regulation strategy of the first pressure supply unit or the main control unit is adjusted so that the second pressure supply unit is used as a controllable or adjustable pressure trap and pressure source during pressure reduction. The pressure difference with the wheel brake pressure can be detected by determining the piston position and adjusted accordingly. With this valve connection variant II, one or more outlet valves can also be omitted. For example, four dedicated solenoid valves can be used as de-energized open inlet valves and two de-energized closed outlet valves on the front axle. In this way, no outlet valve is needed on the rear axle. Such a system features high dynamic performance and low noise levels.

[0093] In valve connection variant II, the present invention can use a third pressure control method C (p auf EV Δt p ab (1): EV PWM p ab (2): AV Δt A pressure control method is used, in which pressure is reduced by controlling the variable valve cross-section of the inlet valve. Unlike valve connection variant I, pressure reduction can be achieved simultaneously and smoothly through multiple inlet valves. This is particularly advantageous for low-noise control operation of electric vehicles. In one embodiment, pressure is increased by pressure control method B (multiplexing / PPC pressure control) or pressure control method C.

[0094] This leads to implementation methods using different pressure control approaches, which are summarized in the table below:

[0095] According to the present invention, pressure increase (p) can be achieved without redundancy. auf ) and pressure reduction (p ab As an example, it can be done solely through the inlet valve (EV) (see the first column of the table with "p"). auf Pressure increase is achieved through the row “(EV)” and can be achieved solely through the outlet valve AV (see the first column of the table with “p”). ab (AV) line) achieves pressure reduction.

[0096] However, according to the redundancy settings shown in the table, it is preferable to equip the inlet valve with redundant solenoid coils and redundant actuators as a redundancy configuration for pressure rise (see “p” in the first column of the table). auf (EV), the line for "redundant electromagnetic coil / driver".

[0097] In some embodiments, this can be achieved via an outlet valve (see column 1 of the table with "p"). ab (AV) row) or inlet valve (see the first column of the table with "p"). ab (EV) line) Reduce pressure to ensure redundant configuration for pressure reduction. Without this redundancy in hardware and software, pressure reduction cannot be achieved through the outlet valve, for example, if the solenoid coil of the outlet valve fails, because the valve is closed when there is no current, thus hindering the pressure reduction operation. This could result in permanent blockage of the relevant wheel brakes.

[0098] The driving dynamics system of the present invention has a general advantage: it enables easier and more efficient intervention of braking torque for each wheel and novel control strategies for regenerative braking. Unlike the prior art, in at least some embodiments, a dedicated solenoid valve can be used to maintain the pressure in the brakes of selected wheels while changing the braking pressure in the brakes of other wheels.

[0099] If pressure reduction is achieved via a dedicated solenoid valve, unlike the conventional method of pressure reduction via an outlet valve, the pump of the first pressure supply unit must be controlled to restore pressure. This is particularly applicable to the embodiments described in configurations (C) and (D) above. However, this method is also feasible in configuration (B) for ABS operation with a low coefficient of friction (“low-μ”). Configuration (E) also has corresponding advantages if a controllable or adjustable pressure trap, such as a rotary pump, is provided in one embodiment of the first pressure supply unit, and this pressure trap can reduce pressure by reversing the direction of rotation.

[0100] The objective mentioned at the beginning can be further addressed by a method. In particular, this objective can be addressed by a method for adjusting the braking pressure of at least one wheel brake in a braking system, the method comprising the following steps: Determine that the pressure in at least one of the wheel brakes, i.e. the target wheel brake, needs to be reduced; Select the buck mode from the first buck mode and the second buck mode; When the first pressure reduction mode is selected, at least one of the outlet valves associated with the target wheel brake is opened to perform pressure reduction; When the second pressure reduction mode is selected, the outlet valve associated with the target wheel brake is kept closed, at least one inlet valve associated with the target wheel brake is opened, and a pressure differential is formed (externally) preferably in the second pressure supply unit so as to reduce the pressure in the target wheel brake through the inlet valve.

[0101] Therefore, one aspect of the present invention is that different modes can be selected to achieve the optimal pressure reduction effect according to specific circumstances. In at least one mode, pressure reduction is achieved through a (dedicated) inlet valve. On the one hand, this improves availability (e.g., operation continues even if some valves fail); on the other hand, this results in smaller pressure fluctuations during pressure reduction, and thus lower noise. Pressure can also be applied if the outlet valve malfunctions (the outlet valve closes when power is off); The pressure reduction process can be adjusted or controlled by an external pressure source according to the pressure gradient and / or pressure gradient curve; If valve connection variant II is selected, pressure reduction can be smoothly achieved through a dedicated valve.

[0102] In the context of this invention, keeping a valve closed, especially an outlet valve, does not necessarily require actuating the valve in any way. Rather, according to this invention, normally closed valves, commonly used as outlet valves, can be kept closed by not applying current and not outputting any type of activation signal.

[0103] Alternatively, the above objective can be achieved by a method for performing ABS braking in a vehicle, wherein the method includes: Determine the required pressure reduction gradient for at least one wheel brake; Select a pressure setting mode from a plurality of pressure setting modes using the required pressure reduction gradient, wherein the plurality of pressure setting modes includes at least a first pressure setting mode and a second pressure setting mode; If the first pressure setting mode is selected, the pressure of at least one wheel brake is reduced by a timer through at least one outlet valve; If the second pressure setting mode is selected, the wheel brakes are depressurized only through another solenoid valve (especially when the outlet valve is closed), through which the pressure of the wheel brakes is transmitted to a controllable / adjustable pressure trap.

[0104] Therefore, the mode used for pressure reduction is selected based on the required pressure reduction gradient. Alternatively, factors such as the volume of fluid to be depressurized or the pressure difference can also be considered when making the selection.

[0105] As already explained, the first pressure setting mode can be the standard pressure setting mode. The second pressure setting mode can be the dedicated pressure setting mode I.

[0106] In one embodiment, the multiple pressure setting modes include a third pressure setting mode, such as a dedicated pressure setting mode II. When the third pressure setting mode is selected, pressure reduction of at least one wheel brake can be performed at least temporarily in parallel by at least one outlet valve associated with the wheel brake and at least one additional solenoid valve associated with the wheel brake. The additional solenoid valve can be a dedicated solenoid valve, as described in conjunction with various embodiments. By using the inlet and outlet valves simultaneously at least temporarily, pressure reduction can be achieved quickly and efficiently.

[0107] In one embodiment, when the second pressure setting mode is selected, a low pressure is set in the pressure trap, for example, less than 5 bar, preferably less than 3 bar.

[0108] The aforementioned objective is also achieved through a main control unit having instructions for implementing at least one of the methods.

[0109] Furthermore, this objective is achieved by a vehicle or driving power system having one of the described main control units, particularly the last described main control unit.

[0110] Further advantageous embodiments are shown in the dependent claims. Attached Figure Description

[0111] The present invention is described below by way of several exemplary embodiments, which are explained in more detail with reference to the accompanying drawings. In the drawings: Figure 1 An ESP hydraulic circuit diagram based on the prior art is shown; Figure 2a An FDS system architecture with a main control unit for the traction motor and two braking modules BM1 and BM2, and multiple auxiliary control units is shown; Figure 2b It shows Figure 2a An exemplary embodiment of the braking module, wherein the isolation valve is a dedicated solenoid valve; Figure 2c The connection for use in the second braking module is shown as follows: Figure 2b A valve connection variation for a dedicated solenoid valve used in isolation valves; Figure 3a A schematic diagram of the first braking module BM1 is shown, in which the two inlet valves of the braking circuit are equipped with dedicated solenoid valves (with 3-channel braking torque modulation function) to prevent passive closure. Figure 3b A schematic diagram of a first braking module connected to a second braking module is shown, wherein the four inlet valves of the two braking circuits in the first braking module are equipped with dedicated solenoid valves (with 4-channel braking torque modulation function) to prevent passive closure. Figure 4a A schematic diagram of a dedicated solenoid valve with a permanent magnet and a return spring is shown. Figure 4b A displacement-force diagram is shown to illustrate the forces acting on... Figure 4a The force on the valve actuator of the special solenoid valve shown; Figure 5a A schematic diagram of a dedicated solenoid valve with a permanent magnet integrated in the valve armature is shown, wherein the armature can be actuated by an electromagnetic field with different polarizations; Figure 5b A displacement-force diagram is shown to illustrate the forces acting on... Figure 4a The force on the valve actuator of the special solenoid valve shown changes with the applied current. Figure 6 It was shown as a basis Figure 5a The H-bridge of the driver for a dedicated solenoid valve is used to generate electromagnetic fields with different polarizations. Figure 7a It shows Figure 3b The illustrated embodiment is a schematic diagram of an improved version of the example, which does not have a USV valve (but has a 4-channel braking torque modulation function). Figure 7b It shows Figure 3b The illustration shows an improved version of the embodiment, which omits the USV valve and replaces the HSV valve with a check valve (with 4-channel braking torque modulation function). Figure 8a A schematic diagram of a first braking module for two wheel brakes with a single piston pump is shown, wherein the two inlet valves are designed as dedicated solenoid valves (to depressurize the accumulator chamber). Figure 8b It shows that according to Figure 8a The illustrated embodiment is a schematic diagram of an improved solution that employs a multi-piston pump (to depressurize the reservoir). Figure 8c It shows that according to Figure 8a A schematic diagram of an improved embodiment is shown, which uses a rotary pump instead of a piston pump (to depressurize the reservoir via an outlet valve and / or to depressurize using a controllable / adjustable rotary pump as a dedicated solenoid valve for the pressure trap); Figure 9 It shows Figure 7b The illustrated embodiment is a schematic diagram of an improved version where there is only one hydraulic connection for the second braking module; Figure 10 It shows Figure 9 The illustrated embodiment is a schematic diagram of an improved version that does not include an energy storage chamber; Figure 11 A schematic diagram visually illustrates the control strategy used for the inlet valve; Figure 12 A schematic diagram visually illustrates the control strategy used for the outlet valve; Figure 13a It shows that Figure 3a A schematic diagram showing the combined use of the first braking module and the electric drive piston-cylinder unit as the second braking module, illustrating the depressurization of the two wheel brakes; Figure 13b It shows that according to Figure 13a A schematic diagram of an example embodiment, in which the pressure reduction in the two wheel brakes is visualized; Figure 14 It shows Figure 3b A schematic diagram showing the combination of the first braking module and the electrically driven piston-cylinder unit as the second braking module, in which the pressure reduction is visualized; Figure 15 It shows that Figure 3b A schematic diagram showing the first braking module combined with a centrifugal pump as a second braking module, where the pressure drop is visualized. Detailed Implementation

[0112] Figure 1 The hydraulic circuit diagram of the first braking module BM1 is shown. This first braking module is designed as a standard ESP unit. The first braking module BM1 functions as the first pressure supply unit. The first braking module BM1 includes: Four time-controlled outlet valves AV1-AV4, each outlet valve is assigned to one of the corresponding wheel brakes RB1-RB4; Four PWM-controlled inlet valves EV1-EV4 are assigned to one of the corresponding wheel brakes RB1-RB4. Four check valves are arranged parallel to one of the inlet valves EV1-EV4 and are therefore assigned to a corresponding wheel brake among wheel brakes RB1-RB4. Depending on pressure conditions, the check valves are arranged such that they close when the pressure in wheel brakes RB1-RB4 increases and open when the pressure decreases. Furthermore, when valves USV1 and USV2 are closed, valves HSV1 and HSV2 enable the delivery of brake fluid via pump P, driven by motor M, thereby increasing the pressure. Finally, pump P and motor M form a dual-piston pump (first pressure generator DV1), with each piston serving a first brake circuit BK1 and a second brake circuit BK2. Accumulator chamber Spk allows brake fluid to be absorbed via outlet valves AV1-AV4 during pressure decreases. The arrows in the figure indicate the possible flow directions of the brake fluid during pressure increases and decreases.

[0113] Figure 1 The first braking module BM1 shown provides ESP and ABS functions. The ESP function is well-known and has been described in detail in relevant literature; this function requires twelve solenoid valves. For the ABS function, only inlet valves EV1-EV4 and outlet valves AV1-AV4 are required, which is eight solenoid valves. The first braking module BM1 has two braking circuits BK1 and BK2, which are connected to the second pressure supply unit through two connection points. This could be one of the following scenarios: I. Existing vacuum brake boosters; II. Electric follow-up brake booster and brake pedal; 3. Brake booster and brake pedal with pedal feel simulator; IV. Second pressure generator DV2 with valve.

[0114] Figure 1 The first pressure supply unit has a pressure sensor p / u, which is configured to detect the pressure in the brake circuit BK1.

[0115] The various functions of a modern driving power system are shown in the table below:

[0116] And as shown in the table below:

[0117] Figure 2aThe architecture of a driving dynamics system (FDS) according to the present invention is shown. This driving dynamics system is equipped with first and second traction motors TM1 and TM2 on the rear axle HA of the vehicle, and a third traction motor TM3 on the front axle VA of the vehicle. The system may have a braking module BM1 and optional additional braking modules, such as a second electro-hydraulic braking module BM2. A key element of the driving dynamics system is the main control unit M-ECU chassis domain, abbreviated as M-ECU, which controls the braking torque of the traction motors TM1, TM2, and TM3 and the braking modules BM1 and BM2 to perform at least one of the following functions: A) Emergency braking system (AEB) with synchronized electronic brake force distribution (EBD); B) Regenerative braking for the axle or for the wheel; C) Braking operation is performed via the electric motor when the braking module fails; D) Specific braking torque intervention for steering assistance or vehicle stability at the wheel.

[0118] The main control unit (M-ECU) sends setpoint values ​​to each unit, including, in particular, the braking setpoint torque or braking setpoint pressure. For certain functions, setpoint signals can be specified for pressure control or pressure regulation, such as control signals for solenoid valves and / or pre-pressure for the second braking module BM2 with a second pressure generator (DV2) when pressure increases or decreases.

[0119] In one exemplary embodiment, the main control unit M-ECU has a control unit M-ECU AD This could be an interface connected to the autonomous driving domain, and further information could be evaluated to aid in effective and predictive control. This includes, for example, camera information about road conditions (snow, ice, rain) or information about the surrounding environment (distances to pedestrians and / or other vehicles).

[0120] Figure 2b A so-called dual-box braking system is shown, comprising a first braking module BM1 and a second braking module BM2. The first braking module BM1 has a... Figure 1 The first braking module has a similar structure and possesses the functions outlined above. The second braking module BM2 has a piston-cylinder unit (also called a plunger) driven by a spindle driver. The piston-cylinder unit forms the second pressure generator DV2. Two isolation valves TV1 and TV2 are configured as part of the second braking module BM2, which can separate the braking circuits BK1 and BK2 from the second pressure generator DV2, enabling the core functions to be realized: Brake booster; Automatic emergency brake (AEB); Electric Braking Force Distribution (EBD); 2-channel ABS function in multiplexing / PPC mode.

[0121] In one embodiment of the present invention, redundancy functions can be provided to meet the requirements of Level 4 and Level 5 autonomous driving.

[0122] Control units, hereinafter referred to as auxiliary control units S-ECU1, S-ECU2a, and S-ECU2b, are provided in the two braking modules BM1 and BM2. These auxiliary control units can communicate with each other and preferably have interface functions. 2BM (For example, according to the VDA360 interface definition). Because the brake modules BM1 and BM2 have communication capabilities, and the main control unit M-ECU has (higher level) control functions, the components can cooperate with each other to achieve certain functions. For example, in a hybrid mode, the pressure generator of the second brake module performs pressure increase and pressure decrease operations, while at the same time, the valves in the first brake module, such as the wheel inlet valves EV1-EV4 and the wheel outlet valves AV1-AV4, are also driven.

[0123] Braking modules BM1 and BM2 are connected via interface Int BM1 and Int BM2 Connecting to the main control unit M-ECU enables additional functions such as ABS, ESP, AEB, and ACC, as well as new areas of functionality such as torque vector control (BtTV), brake-steer intervention (BtS), and energy recovery / regeneration management for the electric traction motors TM1, TM2, and TM3. In this case, the braking modules BM1 and BM2 can act as slaves, i.e., pure pressure controllers, and can achieve specified setpoints, such as pressure or braking torque setpoints.

[0124] In at least one operating mode, the (main) interface is used for synchronous actuation of two braking modules BM1 and BM2 by the main control unit M-ECU. For example, the piston of the second pressure generator DV2 of the second braking module BM2 is moved, while one or more solenoid valves of the first braking module BM1 are switched simultaneously. Each braking module is equipped with a separate interface, which allows braking modules BM1 and BM2 to be interchanged as needed, meaning that braking modules BM1 and BM2 can be obtained from different suppliers. Alternatively, only one interface Int can be provided. BM1 or Int BM2 It is communicatively connected to the main control unit M-ECU. In this case, communication with other units is via the standardized interface Int. 2BMIn an exemplary embodiment, wheel speed sensors vR1, vR2, vR3, and vR4 are redundantly read by at least two control units, such as one of auxiliary control units S-ECU1, S-ECU2a, and S-ECU2b, and the main control unit M-ECU, so that the wheel speed signal can always be read through the interface Int. BM1 Int BM2 Int 2BM Transmit the data.

[0125] In the illustrated embodiment, the second braking module BM2 is connected via check valve RV. NF (Alternatively, a solenoid valve can be used instead of the check valve RV) NF The hydraulic connection to the reservoir VB is preferably two three-phase connections (2×3) to meet the requirements of Level 4 and Level 5 automated driving. These two three-phase connections are controlled by auxiliary control units S-ECU2a and S-ECU2b, respectively, which provide current sensors i / u and motor angle sensors α / u. These are preferably also redundantly designed for high-precision PPC pressure control or pressure regulation via piston position or current. Redundancy in certain components of the second braking module BM2 improves availability and creates a third backup level for SAE Level 5 automated driving, similar to the design of steer-by-wire (which has two steering actuators, one of which is equipped with a 2×3 phase motor connection and partially redundant electronics). For example, in the event of pump motor failure or partial motor failure (failure of the motor windings, power output stage on ECU2a or ECU2b of the second braking module BM2), braking torque can still be generated and controlled with approximately 50% of the motor torque. The pressure sensor p / u is preferably located at the output of the pressure source of the second braking module BM2 and is primarily used for calibration purposes. However, if the relationship between the BM2 braking torque and the current or piston position can be determined through other means, then pressure regulation or control can be performed even without this pressure sensor. This also gives the system further redundancy.

[0126] exist Figure 2bIn the illustrated embodiment, two dedicated solenoid valves MV2k are used as (loop) isolation valves TV1 and TV2 in the second braking module BM2. These dedicated solenoid valves MV2k are specifically designed to prevent passive shut-off, enabling them to be used for increasing and releasing pressure at high flow rates Q. Preferably, these dedicated solenoid valves are suitable for implementing pressure changes for ABS operation in a highly dynamic manner (i.e., pressure gradient >1000 bar / s, preferably >2000 bar / s) under multiplexing / PPC methods. These dedicated solenoid valves are designed according to system specifications, i.e., to withstand the maximum braking pressure and maximum volumetric flow rate requirements, and to possess passive shut-off prevention characteristics.

[0127] In one embodiment, the following was adopted: Figure 4a or Figure 4b The dedicated solenoid valve MV2k shown has a first soft ferromagnetic circuit EM1 and a second magnetic circuit EM2, or as shown in the figure. Figure 5a The diagram shows a dedicated solenoid valve MV2k with a magnetic circuit EM1 and a permanent magnet PM embedded in the valve armature. When using the dedicated solenoid valve MV2k with a permanent magnet PM embedded in the armature, the H-bridge is preferably used for current control, as shown in the reference. Figure 6 This will be explained in more detail. The dedicated solenoid valve MV2k can then operate in a current-controlled manner with a variable valve cross-section during pressure rise and fall. This enables low-noise and high-precision pressure control, particularly during pressure rise and fall. In the latter embodiment, the magnetic circuit EM1 and the excitation coil SP1 can be used to generate magnetic forces of different magnitudes in the two directions of movement. The advantageous positioning of the permanent magnet PM allows for the generation of a restoring force even in the power-off state, thus eliminating the need for a return spring RF. However, according to the invention, in addition to the permanent magnet PM, at least one return spring RF may be provided, for example, as... Figure 4a or Figure 4b As shown.

[0128] As Figure 4a or Figure 4b and Figure 6 An alternative to the valve shown is a standard valve with a magnetic circuit EM1 but without a permanent magnet, which can be referenced from the prior art in a single-box braking system (DE102013222281A1). Figure 1 The valves shown by reference numerals 26a and 26b in the accompanying drawings can also be used as dedicated solenoid valves. According to the invention, these valves are designed based on the pressure differential and pressure change rate of the functions to be performed (especially AEB and ABS functions). Depending on the requirements of different functions, solenoid circuits with larger armatures and / or stronger return springs can be used.

[0129] The first braking module BM1 operates independently in the standard pressure setting mode (pressure control method A), while the braking module BM2 operates using pressure control method B. Furthermore, according to the present invention, if ABS operation is performed under conditions of extremely low road surface friction coefficient (low-μ) and split road surface friction coefficient (μ-splitting), then switching can be made between the standard pressure setting mode and the dedicated pressure setting mode I. In the dedicated pressure setting mode I, pressure can be reduced via a dedicated solenoid valve, and the braking module BM2 can be used as a pressure sink with pressure below 5 bar (especially below 3 bar).

[0130] This switching option also exists in other embodiments of braking systems with dual braking modules having an accumulator chamber and a braking module (see...). Figure 3a , 3b (7a and 7b), and will not be described separately below.

[0131] Figure 2c The valve seat VS is shown (e.g., in...) Figure 5a (As shown) and the advantageous connection between the armature chambers of the isolation valves TV1 and TV2 and the braking circuits BK1 and BK2. Therefore, the armature chamber AR (e.g. in Figure 5a (As shown) The pressure generator DV2 is hydraulically connected to the second braking module BM2, and the seat of the dedicated solenoid valve MV2k is hydraulically connected to the braking circuit. This arrangement allows for setting the valve opening cross-section, particularly during pressure reduction, using PWM control or current control, thereby achieving low-noise pressure reduction. In this configuration, the pressure rise process is achieved through controlled or regulated volume metering using the second braking module BM2, wherein the isolation valves TV1 and TV2 are preferably time-controlled during pressure rise, and the pressure rise process is performed using a multiplexing / PPC method.

[0132] When using, such as Figure 5a When the dedicated solenoid valve MV2k is shown, it passes through the H-bridge (see...). Figure 6 Specific current control can also enable the pressure rise process to be achieved with a variable valve cross-section, thus avoiding the dead time in the multiplexing / PPC method and achieving synchronous pressurization without placing excessive demands on the actuator. In this embodiment, the connection direction is irrelevant because, as Figure 5a The dedicated solenoid valve MV2k shown can throttle in both directions. Furthermore, it can operate with a passive shut-off protection function.

[0133] Figure 3a (abbreviated as ESP-X) 3k，12MV，4RB，SK，KPThis illustrates an example embodiment of the first braking module BM1 according to the present invention, which in this embodiment is a three-channel braking system having twelve solenoid valves, four wheel brakes RB1-RB4, an accumulator chamber Spk, and a piston pump. The difference from a standard ESP system is that the two inlet valves EV1 and EV2 in the first braking circuit BK1 are designed as dedicated solenoid valves MV2k. Because these valves possess special anti-passive-closing characteristics, the check valve can be omitted (see...). Figure 1 The parallel structure of RV in the middle.

[0134] In one embodiment, the dedicated solenoid valve MV2k is equipped with redundant solenoid coils MS1, MS2 and redundant solenoid valve actuators, making redundant operation possible, or the solenoid valve actuators can be controlled via the main control unit M-ECU. In the illustrated embodiment, the first braking circuit BK1 corresponds to the front axle braking circuit of a vehicle with a II braking force distribution. This means that the wheel brakes RB1, RB2 are the wheel brakes of the front axle VA of the vehicle.

[0135] In an alternative embodiment, an X-braking circuit distribution can be selected. In the minimum configuration, the inlet valves EV1 and EV2 of the wheel brakes RB1 and RB2 assigned to the front axle VA can be designed as dedicated solenoid valves MK2k in this embodiment. This modification to the standard braking system achieves a significant improvement because the 2-circuit braking system becomes a 3-circuit braking system, where for the two wheel brakes (see...) Figure 3a The wheel brakes RB1 and RB2 in the system are redundant during pressurization and depressurization. Contrary to the prior art, if one of the first or second wheel brakes RB1 or RB2, for example, wheel brake RB1, fails, the corresponding wheel brake circuit can be disconnected by closing the inlet valve EV1 assigned to the failed wheel brake RB1. This means that the remaining three wheel brake circuits, including wheel brakes RB2-RB4, can continue to operate normally. Furthermore, if the solenoid coil of one of the outlet valves AV1 or AV2 fails, redundant depressurization can be achieved through the corresponding inlet valves EV1 or EV2. This presupposes that the corresponding driving dynamics system has a controllable pressure trap, for example, by providing a corresponding second braking module BM2. Using this method according to the invention, a significant improvement in achievable deceleration can be achieved compared to the prior art, because in the event of a failure, either (a) one wheel brake RB1 or RB2 on the front axle VA and two wheel brakes RB3 or RB4 on the rear axle HA can be used for braking, or (b) two wheel brakes RB1 or RB2 on the front axle VA can be used for braking.

[0136] In one exemplary embodiment, the interface between the aforementioned brake modules conforming to the German Association of the Automotive Industry (VDA) 360 standard is extended in such a way that, in addition to the interface described in DE102012211278A1, inlet valves EV1 to EV4 can also be actuated externally. This means that if one wheel circuit fails, yaw rate control (ESP), torque vector control via braking torque intervention (BtTV) for the wheels, and selective braking torque intervention for steering (BtS) can still be achieved using the remaining three brake circuits. This method of the invention also has the advantage of retaining all the functions listed in the table above without major software modifications, especially in the first brake module BM1. The software components used for pressure increase must be modified to enable the additional three-loop control function in the event of a wheel circuit failure. Furthermore, since pressure can be maintained at the two aforementioned wheel brakes RB1-RB4 via dedicated solenoid valves, a control strategy that allows the main control unit M-ECU to set the pressure can be implemented with less development effort. In this way, by using specially configured inlet valves EV1-EV4 and the second braking module BM2, pressure boosting and depressurization operations can be performed individually for each wheel. When performing braking torque control or braking torque regulation for specific wheels, it is not necessary to use outlet valves AV1-AV4 (such as...). Figure 3b All isolation valves TV1-TV4 shown are implemented using dedicated solenoid valves, or outlet valves AV1 and AV2 (using... Figure 3a The implementation shown reduces pressure and eliminates the need for time-consuming brake fluid recovery via pump P. If recovery is not required, the complex pressure oscillation compensation of the second brake module BM2 can be omitted during the recirculation of the first brake module BM1, which has beneficial effects on reducing noise and wear.

[0137] A hybrid strategy for a dual-box braking system is described in WO2018234387A1 (pages 23-25), which can also be used for braking torque control of specific wheels or for torque vectoring or steering intervention. The hybrid strategy or wheel-specific braking torque intervention can be implemented more easily with the help of a dedicated solenoid valve MV2k. Furthermore, degrees of freedom can be created because if the pressure supply unit of the second braking module BM2 sets different pre-pressures for different wheel brakes, then the pressure in wheel brakes RB1-RB4 can be maintained.

[0138] In one exemplary embodiment, the first braking module BM1 can be extended by two check valves RV1 and RV2, which are part of the connection between the pump P of the braking circuits BK1 and BK2 and the reservoir VB (see [link]). Figure 3a (The dashed line in the diagram). Compared to existing technologies, the combination with the second braking module BM2 enables the pump to achieve rapid priming, which is much faster than priming through valves HSV1, HSV2, and other hydraulic resistances.

[0139] Figure 3b (abbreviated as ESP-X) 4k，12MV，4RB，SK，KP This illustrates a first braking module BM1 according to the invention, which is a 4-channel braking system with twelve solenoid valves, four wheel brakes RB1-RB4, an accumulator chamber Spk, and a piston pump KP. The difference from the standard ESP is that in the two braking circuits BK1 and BK2, all inlet valves EV1-EV4 and their corresponding check valves RV1-RV4 (see...) Figure 1 All of these are replaced by dedicated solenoid valves MV2k. In this example embodiment, a 4-circuit braking system is generated. This example embodiment creates more degrees of freedom for braking torque control for specific wheels and provides a simple pressure interface for the main control unit M-ECU. By creating a 4-circuit braking system in the first braking module BM1, the division of braking circuits in the second braking module BM2 can be eliminated. For example, as described in WO2020165294A2, the second braking module may include a simplified master brake cylinder (HZ) with only one piston (so-called single-piston master brake cylinder SHZ) and a pressure chamber, wherein the master brake cylinder is preferably designed with redundant seals, and wherein SHZ only needs to be connected to one braking circuit, such as the front axle braking circuit. If the wheel circuit in the first braking module fails, it is only necessary to ensure that the brake circuit of the failed wheel is disconnected if the pump P also fails. According to the invention, this can be achieved by corresponding inlet valves EV1-EV4, which are capable of internal and external control. For this purpose, the dedicated solenoid valve MV2k is equipped with redundant coils and solenoid valve actuators.

[0140] Figure 4a A first advantageous embodiment of the MV2k solenoid valve, which features anti-passive shut-off and bidirectional current-free opening, is shown. According to the invention, the term "bidirectional" can be understood to mean that the pressurization and depressurization processes are performed via the MV2k valve. The dedicated solenoid valve MV2k operates reliably in both flow directions Q, especially at high flow rates (e.g., 100 cubic centimeters per second). 3 / s)-120 cm 3 When there is a large pressure difference (e.g., 160 bar - 220 bar) between the connection point and the connection point.

[0141] The dedicated solenoid valve MV2k has a typical solenoid valve structure, including a magnetic circuit EM1, an armature 6, and a valve actuator 7, which includes a valve pusher 7a that closes the valve seat VS. Additionally, a return spring RF is provided, which has a linear force curve and acts on the valve actuator 7. The return spring pre-tensions the dedicated solenoid valve MV2k to its initial position. Figure 4a (The location shown).

[0142] Especially for the aforementioned large pressure variations and flow ranges, the dedicated solenoid valve MV2k ensures that it will not automatically close due to dynamic flow forces. This is critical when there is high pressure at the armature chamber AR and low pressure at the hydraulic connection acting on the valve seat VS. The hydrodynamic flow generates a force F. hyd This force acts on the valve tappet, causing it to move towards the valve seat VS. The return spring RF counteracts the dynamic fluid force, but in extreme cases, it is insufficient to actively prevent passive closure under the influence of the dynamic fluid force.

[0143] Electromagnetic circuit (magnetic circuit) EM1 (see) Figure 4b This will generate a magnetic force F that is related to the current and position. EM1 =f(i SP (This magnetic force acts throughout the entire stroke s), causing the armature to move towards the stop and the valve tappet 7a to move towards the valve seat VS. The magnetic force curve is non-linear and increases as the air gap S decreases. Figure 4a And gradually increase, especially following the polynomial formula FM EM1 = (S max - s) n , n = 1.4 - 2 (where, as the stroke s increases or the armature 6 and the stop (i.e. s) are engaged ... max The air gap S between -s) decreases. Magnetic force can change with the current i. SP The magnetic force increases with the increase of the fluid flow rate Q, but is limited by magnetic circuit saturation. However, the magnetic force can only act in the direction of the valve seat VS, so if the fluid flow rate Q originates from the armature chamber, it cannot generate the same fluid dynamic force F. hyd The valve can remain active when pressure is applied to the valve seat if it is closed. If fluid flows from the VS side of the valve seat, a reaction force is generated, meaning that operation with a variable valve opening cross-section is also possible. In other words, the dedicated solenoid valve MV2k can operate with a variable valve opening cross-section like a proportional valve. In technical terms, this type of control is also simply called PWM control.

[0144] To enable the dedicated solenoid valve MV2k to have an anti-passive shut-off function, a permanent magnet PM is incorporated in the first variant design as a passive additional force device to increase the restoring force F caused by the return spring RF. RF A permanent magnet circuit includes a permanent magnet PM and a pole plate 10. The permanent magnet is integrated into an additional armature 6a, which is connected to the armature 6 in a non-positive manner. The magnetic poles are aligned parallel to the longitudinal direction of the dedicated solenoid valve MV2k, so that the magnetic force F generated by the permanent magnet PM... PM Will be related to recovery ability F RF The combined effect, that is, the total force F ges = F PM + F RF .

[0145] Magnetic force F PM The characteristic is that the force is relatively large when the valve is open, and decreases as the stroke s increases. At the end of the stroke (i.e., s = s...), the force decreases further. max (Time), magnetic force F PM It remains high enough to perform a conventional armature reset. With proper design, the reset spring 13 can be replaced if the magnetic force FEM1 generated via coil SP2 and main magnetic circuit EM1 is also large enough to overcome the reaction force from the permanent magnet or the reset spring. This can be achieved by accordingly shaping the characteristic curve of the magnetic circuit (EM).

[0146] Alternatively, the additional restoring force of the first magnetic circuit EM1 can also be generated by the second magnetic circuit EM2. The second magnetic circuit EM2 is generated by the current in the second coil SP2, where the magnetic field passes through the additional armature 6a, preferably made of a ferromagnetic material. This means that in this variant, a force is also generated that interacts with the restoring force F of the return spring RF. RF Similarly, it will affect the hydrodynamic F hyd This has the opposite effect. In this variant, armature 6 is also mechanically connected to an additional armature 6a.

[0147] In one embodiment example, if the size of the additional force device is determined accordingly, the return spring RF can be omitted.

[0148] A key aspect of the dedicated solenoid valve MV2k is the total force F. ges The force varies substantially linearly throughout the entire stroke. Preferably, the force increases when leaving the starting or initial position. The characteristic force distribution along the stroke s is as follows: Figure 4b As shown. The figure also illustrates the dedicated solenoid valve MV2k according to the invention, which has the same characteristics as valves conventionally used in this field (see restoring force F). RF Significantly different force distributions (see F)ges ).

[0149] Figure 5a A second advantageous embodiment of the dedicated solenoid valve MV2k is shown, which features anti-passive shut-off capability, bidirectional operation, and is normally open. The dedicated solenoid valve MV2k is suitable for the applications described in the first braking module BM1 (as inlet valves EV1-EV4) and the second braking module BM2 (as isolation valves TV1, TV2).

[0150] The dedicated solenoid valve MV2k employs a typical design of a solenoid valve with a magnetic circuit EM1. This dedicated solenoid valve has an armature 6, a valve actuator 7 with a valve tap 7a, and a valve seat VS. In an embodiment, a ring-shaped permanent magnet PM is integrated into the armature 6, which is surrounded by soft magnetic elements (magnetic flux conductors). The magnetic poles of the permanent magnet PM are aligned perpendicular to the longitudinal direction of the dedicated solenoid valve MV2k. Alternatively, multiple permanent magnets PM can be arranged radially accordingly. The electromagnetic field EM1 is generated by an excitation current flowing through a coil SP1a, which extends in a ring path within a portion of the housing of the dedicated solenoid valve MV2k. The magnetic circuit EM1 extends to the housing, its left leg (loop branch) crossing a first air gap via the magnetic flux conductor in the armature and closing via a second air gap through a right leg (loop branch), wherein both branches (legs) are arranged on the housing and are magnetically conductive. A large air gap separates the left and right legs so that the electromagnetic field does not close directly from the left leg to the right leg. When energized, magnetic poles are formed on the branches (legs) of the magnetic circuit, which attract or repel the permanent magnet PM according to the direction of the current passing through the excitation coil SP1a (that is, the direction of the magnetic flux).

[0151] In this embodiment, the remaining armature 6 is made of a non-conductive electromagnetic material. For example, it can be made of an inexpensive plastic component, which preferably also includes a valve actuator 7. In the initial position, the armature 6 is positioned such that the magnetic flux conductor is closer to the left leg than the right leg. Thus, the armature 6 is subjected to... Figure 4a magnetic force F PM and / or restoring force F RF The force effect is equivalent to the valve-opening force. Therefore, the return spring RF can be eliminated. Furthermore, the restoring force through the magnetic flux conductor has a smaller tolerance (error range) compared to the return spring RF, because the design of the solenoid valve circuit is easier to reproduce.

[0152] exist Figure 5a In the illustrated embodiment, an H-bridge with four power semiconductors (see...) is used. Figure 6The excitation coil SP1a is controlled by the electromagnetic field EM1. This makes it possible to change the direction of the magnetic flux by reversing the direction of the current. Therefore, the electromagnetic field EM1 can increase or decrease the force acting on the permanent magnet PM. The magnetic field can also be reversed so that the dedicated solenoid valve MV2k can be closed. Thus, the armature 6 can be moved to the right or left in the image plane via current regulation or current control.

[0153] The advantage of the described embodiments is that the valve has a very simple structure. From Figure 6 As can be seen, the H-bridge contains four power semiconductors, and the magnetic flux direction can be determined according to the switching method of the power semiconductors. If power semiconductors S2 and S3 are switched, currents i1 and i2 generate a first magnetic flux direction, causing the north pole to form on the left leg and the south pole to form on the right leg, and the armature 6 is magnetically repelled, i.e., the valve is closed. If power semiconductors S1 and S4 are switched, current i3 generates a second magnetic flux direction, thus forming a south pole on the left leg, and the armature retracts, meaning the valve is either opened or held in the open position. Due to the control via the H-bridge according to the present invention, the restoring force can even be enhanced by the permanent magnet PM, meaning the valve is very resistant to passive closure and can be opened very quickly. The advantage of rapid opening is that the dwell time (typically 2ms) during the pressure reduction due to the valve opening process can be reduced to less than 1ms. This allows for rapid pressure reduction without wasting time, which has a beneficial effect on the control quality of ABS and braking distance. Furthermore, the cross-section of the dedicated solenoid valve MV2k can be controlled very precisely during pressure rise, and this method allows for the easy achievement of a large valve opening cross-section, with the advantage of reducing throttling effects during large valve strokes. Using the control via the H-bridge according to the invention, the dedicated solenoid valve MV2k can operate in a current-controlled manner with a variable valve cross-section during both pressure rise and pressure fall. This enables pressure control with exceptionally low noise and high precision during both pressure rise and pressure fall processes.

[0154] In one embodiment, the dedicated solenoid valve MV2k is equipped with a large cross-section, which significantly reduces the throttling effect during pressure rise. This reduces the time required to reach the blocking pressure.

[0155] The described dedicated solenoid valve MV2k provides the possibility of eliminating several outlet valves AV1-AV4, especially the two outlet valves on the wheel brakes RB3 and RB4 of the rear axle HA, because dual-channel multiplexing operation can be easily achieved using such valves.

[0156] Figure 5b The magnetic force F acting on armature 6 is shown. EM1(See the variation of bias force VK and restoring force RK) with distance s. (Dashed line s) max This indicates the maximum distance that valve tappet 7a travels when the dedicated solenoid valve MV2k is closed. If the dedicated solenoid valve MV2k is not energized (i=0), a relatively large restoring force will be generated in the initial position (s = 0), which will decrease as the distance s increases. However, in the closed position (s = s... max Even when the valve is closed, it still has a restoring force, thus preventing accidental passive closure. When a negative current (i = i3) is applied, a significantly stronger restoring force is generated over the entire distance s.

[0157] When a weak positive current (i = i1) is applied, the restoring force exists only in positions close to the initial position. Once this restoring force is absent, the bias force comes into play to force the valve pusher into the closed position. When a stronger positive current (i = i2) is applied, the bias force acts over the entire stroke s, allowing the dedicated solenoid valve MV2k to close in a controllable manner.

[0158] Figure 7a (abbreviated as ESP-X) 4k，10MV，4RB，SK，KP The diagram illustrates another embodiment of the first braking module BM1, in which valves USV1 and USV2 are omitted without causing functional limitations. The braking module has four circuits, ten solenoid valves, four wheel brakes, and two accumulator chambers Spk. This assumes that the first braking module BM1 operates in conjunction with the second braking module BM2, which powers two independent braking circuits BK1 and BK2 and has isolation valves TV1 and TV2 in the form of dedicated solenoid valves MV2k (e.g., ...). Figure 2b (As shown). Isolation valves TV1 and TV2 will take over the functions of valves USV1 and USV2, especially in the event of ESP intervention. To achieve this solution, another interface needs to be provided between brake modules BM1 and BM2. The advantage of this approach is that the throttling resistance between the pressure generator DV2 of the second brake module BM2 and the wheel brakes RB1-RB4 is reduced, resulting in a faster system response, which is particularly effective in situations such as emergency braking.

[0159] Figure 7b (abbreviated as ESP-X) 4k，8MV，4RB，SK，KPThe diagram shows the first braking module BM1, where valves USV1, USV2 and valves HSV1, HSV2 are omitted. The braking module has four circuits, eight solenoid valves, four wheel brakes RB1-RB4, two accumulator chambers Spk, and a piston pump KP. To implement the functions of valves HSV1 and HSV2, two check valves RV1 and RV2 are provided, which establish a connection with the reservoir VB. This further reduces costs without limiting functionality or the scope of operation.

[0160] Figure 8a (abbreviated as ESP-X) 2k，4MV，2RB，SK，KP An example embodiment is shown, which is a... Figure 7b An improvement to the illustrated embodiment is required. This necessitates only four valves (two inlet valves and two outlet valves). The first braking module can be used on one axle of a two-wheeled vehicle or a multi-axle vehicle. It is connected to exactly two wheel brakes RB1, RB2, wherein each wheel circuit can be individually isolated via a dedicated solenoid valve MV2k acting as isolation valves TV1, TV2.

[0161] If wheel brakes RB1 and RB2 fail, the remaining wheel braking circuits can still operate, and braking torque can be applied or reduced. The first braking module BM1 preferably also provides an interface Int to the main control unit M-ECU. BM1 In this way, the target parameters for braking torque intervention on specific wheels can be directly set through the main control unit M-ECU. The first braking module BM1 can operate independently in the standard pressure setting mode (pressure control method A); pressure control method B can also be used when an additional pressure supply source DV2 is available. A separately designed pressure generator DV2 or the second braking module BM2 can be hydraulically connected to the braking module BM1 at connection points A1 and A2, or an SHZ can also be connected to it. Figure 2b As shown, in ABS mode, it is also possible to switch between standard pressure setting mode and dedicated pressure setting mode I.

[0162] Figure 8b (abbreviated as ESP-X) 2k、4MV、2RB、VB、MKP(The diagram shows another embodiment of the first braking module BM1 for two wheel brakes RB1, RB2, wherein the pressure generator is a pump with multiple pistons. Pressure is discharged directly into the reservoir VB via outlet valves AV1, AV2. This has the advantage of significantly improving control performance during low-pressure control, particularly in icy and snowy conditions, because the back pressure of the accumulator chamber SpK does not limit the pressure gradient during the depressurization process. In this embodiment, it is not necessary to set a dedicated pressure setting mode I.)

[0163] The first braking module BM1 preferably also provides an interface Int to the main control unit M-ECU. BM1 This allows the target parameters for VMC intervention of specific wheel braking torque to be directly specified via the main control unit M-ECU. The first brake pressure module BM1 operates autonomously using pressure control method A; pressure control method B can also be used when an additional pressure generator DV2 is present.

[0164] Figure 8c (abbreviated as ESP-X) 2k、4MV、2RB、VB、MKP ) shows a with Figure 8a A similar embodiment is shown, featuring a first braking module BM1 for both wheel brakes. A rotary pump RP is provided as a pressure generator DV1, through which pressure can be built up and released by reversing the direction of rotation. Dedicated solenoid valves MV2k, arranged as inlet valves EV1, EV2 and connected to wheel brakes RB1, RB2, are equipped with redundant excitation coils and redundant drivers. Typically, in all embodiments of the invention, it is feasible to equip them with corresponding redundant devices.

[0165] Two outlet valves AV1 and AV2, associated with wheel brakes RB1 and RB2, are hydraulically connected to the reservoir VB for effective pressure reduction. An advantage of this embodiment is the existence of several degrees of freedom for pressure reduction, which can be used to improve availability in the event of partial failure or to improve control and pressure control options. For example, from the perspective of the first brake module BM1, pressure can be reduced completely independently via outlet valves AV1 and AV2. Furthermore, pressure can be built up and reduced by means of an external pressure generator DV2, which is provided separately or as part of the second brake module BM2. Therefore, this embodiment is particularly suitable as a cost-effective axle module and is preferably centrally controlled.

[0166] Typically, in all the embodiments described, the rotary pump RP can be used additionally or separately as the first pressure generator DV1 or the second pressure generator DV2. When used as the first pressure generator DV1 in the first braking module BM1, the check valve RV1 between the pump and the reservoir VB can be omitted (see example...). Figure 3b One advantage of using a rotary pump RP for pressure reduction is that the pressure reduction gradient is not limited by the back pressure of the accumulator chamber Spk, and it can be used to improve ABS control performance under low friction coefficient (low μ) conditions, even without an external pressure generator DV2.

[0167] like Figure 3b The first braking module BM1 shown preferably also provides an interface Int to the main control unit M-ECU. BM1 This allows the target parameters for VMC intervention of specific wheel braking torque to be directly specified via the main control unit M-ECU. The first braking module BM1 operates independently in pressure control mode A or dedicated pressure setting mode II (with the rotary pump acting as a pressure sink). Pressure control mode B (dedicated pressure setting mode I) can also be achieved via an additional pressure generator DV2.

[0168] Figure 9 It shows something similar to Figure 8a Example of an embodiment. In this embodiment, a (single) hydraulic connection is provided for the second braking module BM2. By using dedicated solenoid valves MV2k on (all) four wheel brakes RB1-RB4, the advantages of a 4-circuit design can be taken advantage of, thus eliminating the need for brake circuit separation.

[0169] Preferably, the embodiment also provides an interface Int to the central control unit, preferably in the form of a main control unit M-ECU. BM1 (Not shown), which allows target parameters for intervention of braking torque for a specific wheel to be specified externally. The first braking module BM1 described operates independently by pressure control method A and can be extended by adding a second braking module BM2 to incorporate pressure control method B (dedicated pressure setting mode I).

[0170] Figure 10 It shows the Figure 9 This is another example of a modified embodiment of the illustrated embodiment. This embodiment does not have an accumulator chamber Spk. To achieve pressure reduction, the wheel brakes RB1-RB4 are hydraulically connected to the reservoir VB via outlet valves AV1-AV4. Only one hydraulic connection is provided for connecting the second brake module BM2. This hydraulic design is consistent with... Figure 8b and Figure 8cThe hydraulic design of the illustrated embodiment is similar. However, the first braking module BM1 is designed for use with all four wheel brakes. This embodiment is suitable as a central hydraulic pressure regulator, controlled via a central computer, such as a main control unit M-ECU.

[0171] The first braking module BM1 has an optional Int connection to the main control unit. BM1 An interface (not shown) allows target parameters for intervention in braking torque at a specific wheel to be specified externally. It operates independently through pressure control method A and pressure control method B.

[0172] Figure 11 An example of a first inlet valve EV1 is shown, as it may be used in some or all of the described embodiments. The inlet valve EV1 is designed as a dedicated solenoid valve MV2k and has redundant coils, each energized by a driver. The first driver (left) is electrically connected to the auxiliary control unit S-ECU1 of the first braking module BM1, where the corresponding inlet valve is used. The second driver (right) is connected to two interfaces Int. 2BM and Int BM1 This allows the second drive to be controlled by at least one auxiliary control unit and the main control unit M-ECU in the auxiliary control unit S-ECU2a of the second braking module BM2.

[0173] In one exemplary embodiment, the auxiliary control unit S-ECU1 implements PWM control using clock control with pulse width modulation, i.e., voltage. A simple switch suffices. Control by the main control unit M-ECU or by the second braking module BM2 is preferably achieved by means of current control i=f(t). The H-bridge described above can be used for this purpose. The H-bridge can be used to adjust the current over time and has greater freedom, especially during pressure build-up and (with proper design) during pressure reduction, particularly for the control of variable cross-section valves. In this way, pressure can be increased and released smoothly. According to an embodiment, the H-bridge can be used as a first driver or a second driver. Alternatively, both drivers can also be operated via PWM control.

[0174] Figure 12 An outlet valve AV1 is shown, which can be used in one or all of the described embodiments. The outlet valve AV1 has redundant coils, each energized via a driver. A first driver (left) is electrically connected to the auxiliary control unit S-ECU1 of the first braking module BM1, where the corresponding outlet valve AV1 is used. A second driver (right) is connected to two interfaces Int. 2BM and Int BM1This allows the second actuator to be controlled by at least one auxiliary control unit and the main control unit M-ECU in the auxiliary control unit S-ECU2b of the second braking module BM2. The outlet valve AV preferably operates in a time-controlled mode, wherein the opening time is controlled by a voltage U=f(t).

[0175] Figure 13a and Figure 13b The pressure build-up via the second braking module BM2 is shown. Figure 13a ) and reduced stress ( Figure 13b This situation is used to illustrate... Figure 3a The functions of the braking modules BM1 and BM2 are illustrated. The corresponding volumetric flow rates are marked schematically. The upper right corner shows the pressure graph as a function of time (t). These graphs visually present the pressure change curves in the wheel brakes RB1 and RB2.

[0176] exist Figure 13a In the illustrated embodiment, pressure buildup is either performed according to pressure control method B (i.e., MUX) in the multiplexing / PPC method, with a delay time Δt. mux Proceed sequentially; or through pressure control method A (i.e., EV). PWM In this method, pressure build-up is performed simultaneously in several wheel brakes RB1, RB2 via pre-pressure control. In the latter method, one valve (e.g., inlet valve EV1) is preferably open, while another valve (e.g., second inlet valve EV2) is PWM controlled. Alternatively, for a given inlet pressure, to set different pressures in wheel brakes RB1, RB2, the two inlet valves EV1, EV2 may be operated with different PWM frequencies or current profiles for different valve opening cross-sections.

[0177] The pressure drop at wheel brakes RB1 and RB2 is determined according to... Figure 13b The pressure reduction is illustrated as an example. Alternatively, according to pressure control method B (MUX) in the multiplexing / PPC method, a dedicated solenoid valve MV2k is used in the closed hydraulic circuit with a delay time Δt. muxThe pressure can be reduced sequentially, or by means of pressure control method A (standard pressure setting mode) in the open hydraulic circuit via outlet valves AV1 and AV2. In this way, the pressure in wheel brake RB1 can be reduced using the multiplexing / PPC method, while the pressure in wheel brake RB2 can be established in parallel via the outlet valves. If very rapid pressure reduction is required, a dedicated pressure setting mode II (not shown) can also be used to reduce pressure in parallel via the outlet valves and a dedicated solenoid valve. If the outlet valves fail, pressure control method A on the wheel brakes can be switched to the multiplexing / PPC method. Due to the alternatives and degrees of freedom, very good control performance can be achieved in every critical driving situation, and redundant 4-channel operation is also feasible.

[0178] Figure 14 This illustrates a pressure reduction scenario in one design of braking modules BM1 and BM2, such as... Figure 3b As explained in the diagram. The volumetric flow rate is schematically marked. In the upper right corner is a pressure graph that varies with time (t), which visually represents the pressure change curves in wheel brakes RB1, RB2, RB3, and RB4.

[0179] According to the control strategy shown here, pressure reduction can be achieved using pressure control method B in the multiplexing / PPC approach, with a delay time Δt. mux This can also be achieved through pressure control method A. In the MUX method, a target pressure is set via the piston-cylinder unit, which is lower than the pressure in wheel brakes RB1 to RB4. Pressure is simultaneously depressurized to the accumulator chamber via outlet valves AV1-AV4 without delay, meaning that the delay time Δt can be avoided. mux In other words, the control system is not expected to cause any limitations under critical driving conditions. Furthermore, the first braking module BM1 can be optimized for noise reduction by controlling a large pressure gradient using the MUX method without generating any noise-inducing vibrations, and by using pressure control method A to achieve a smaller pressure gradient.

[0180] Figure 15 This illustrates the simplest and most cost-effective solution according to the invention, featuring two pressure supply units. (As shown) Figure 15 As shown, brake module BM1 is equipped with only eight solenoid valves, with all wheel inlet valves using dedicated solenoid valves, thus creating a brake module BM1 with four wheel braking circuits. An electric motor-driven rotary pump is used as the second pressure supply unit, replacing the electric motor-driven piston-cylinder unit. Due to the four-wheel braking circuit design, only one hydraulic connection to brake module BM1 is required. Brake module BM1 can function independently, but under normal control conditions, it is best supported by a third brake module BM3.

[0181] In the standard pressure setting mode, pressure is released into the reservoir via the outlet valve, or alternatively, it can be reduced via a rotary pump in parallel. Due to the corresponding rotation direction of the rotary pump, it acts as a pressure sink during pressure reduction. In addition to its high fault tolerance, this embodiment offers numerous degrees of freedom, particularly the option to switch from the standard pressure setting mode (establishing pressure via the inlet valve and reducing pressure by controlling the opening and closing timing of the outlet valve) to dedicated pressure setting mode I and / or dedicated pressure setting mode II. If the first brake module BM1 fails, the rotary pump will take over the pressure increase function. During this process, the wheel pressure control valve will be activated via the main control unit M-ECU or another auxiliary control unit S-ECU2a, S-ECU2b, through... Figure 11 and Figure 12 The communication interface shown (Int) 2BM Int BM1 Simultaneously control.

[0182] In the foregoing description, the dedicated solenoid valve is (primarily) described as a dedicated solenoid valve with an additional force device comprising a permanent magnet and / or a second excitation coil and arranged to provide at least one restoring force acting on the valve actuator or valve tappet. In at least some of the described embodiments and example embodiments, the dedicated solenoid valve can be any anti-passive-closing solenoid valve. Therefore, it is conceivable to achieve anti-passive-closing capability by providing at least one throttle valve that ensures the volumetric flow rate remains at a very low level, preventing the valve from closing.

[0183] Typically, in the control of a pressure supply unit, the passive shut-off effect can be limited by restricting the pressure differential, or more preferably by using a throttle valve (not shown), which is preferably installed upstream of the armature connection of the valve connection in the hydraulic line.

[0184] In some variations of dedicated solenoid valves, the return spring RF can be omitted.

[0185] Furthermore, in at least one of the described embodiments, the driving dynamics system can be designed to automate the functional applications during development, particularly due to its high computing power, through the simple application of the core functions of the main control unit (M-ECU). In at least one of the described embodiments, learning algorithms or artificial intelligence (AI) can be used to assist vehicle operation. When using AI, the main control unit (M-ECU) can take over tasks previously performed by application engineers that are impossible due to the very limited performance and memory constraints of existing microcontrollers (i.e., one of the adjustment / control units of the braking system). For example, the central computer records, evaluates, and applies various functions during vehicle operation, especially those safety-critical functions such as ABS, ESP, and AEB, whether the vehicle is running or stationary (i.e., the vehicle is not moving and adaptation is not time-sensitive). Therefore, it is preferable to design it as a closed hydraulic system, primarily using a pressure supply unit with a two-way valve to build and reduce pressure. This approach has significant advantages, namely, the ability to depict nonlinear relationships using appropriate sensors and characteristic curves (e.g., pressure-volume curves, the relationship between motor current and braking pressure, and the relationship between braking pressure and deceleration when the wheel brakes are heated). Adjustments can also be made during operation based on the detection of environmental influences (e.g., air in the system, heat generation of the wheel brakes). If the nonlinear relationship is mapped into a mathematical function or mapping, the electro-hydraulic braking system can also be applied automatically. If the AI ​​method is consistently applied in the hydraulic braking system (EHB), the advantages of easily adjustable or controllable electromechanical brakes (EMB) disappear, while the lower manufacturing cost of the hydraulic braking system comes into play, as the disadvantage in application cost largely disappears.

[0186] In one exemplary embodiment, the driving power system includes: The main control unit (M-ECU) is used to detect and / or generate steering and braking commands; At least two hydraulically actuated wheel brakes (RB1-RB4), wherein each of the wheel brakes is associated with one of the wheels (R1-R4); At least one electric traction motor has a traction motor control unit, wherein the traction motor (TM1, TM2) is used to drive at least one of the wheels (R1-R4), and the main control unit is communicatively connected to the traction motor control unit to control the traction motor (TM1, TM2) to execute the steering command and the braking command; At least one first electro-hydraulic pressure supply unit (BM1) includes: At least one electric pump unit; At least two connection lines for connecting the wheel brakes (RB1-RB4); Electrically actuated wheel brake pressure regulating valves or brake pressure regulating valves (AV1-AV4, EV1-EV4); and First auxiliary control unit (S-ECU1). At least one of the hydraulically actuated wheel brakes (RB1-RB4) is associated with one of the brake pressure regulating valves and the outlet valve (AV1-AV4), wherein the brake pressure regulating valve is in the form of a dedicated solenoid valve (MV2k), and the dedicated solenoid valve is particularly characterized by preventing passive closure. The driving power system, in particular the main control unit (M-ECU), is configured to release pressure in the at least one hydraulically actuated wheel brake via the associated outlet valve or via the dedicated solenoid valve (MV2k).

[0187] In one exemplary embodiment, at least one of the brake pressure regulating valves is a dedicated solenoid valve (MV2k) with an electromagnetic drive device having a first excitation coil (SP1, SP1a) via which the valve actuator (7) or valve tappet (7a) can be adjusted between the valve open position and the valve closed position; The dedicated solenoid valve (MV2k) has an additional force device, which includes a permanent magnet (PM) and / or at least one second excitation coil (SP1b, SP2), and the additional force device is configured to provide at least one holding force (FEM2, FPM) acting on the valve actuator (7) or the valve tappet (7a); and / or The main control unit (M-ECU) is configured to actuate the dedicated solenoid valve (MV2k) and the first pressure supply unit (BM1) at least in a selected braking mode, such that when the dedicated solenoid valve (MV2k) is opened, the pressure of at least one of the wheel brakes (RB1-RB4) associated with the dedicated solenoid valve (MV2k) is reduced.

[0188] In one exemplary embodiment, the main control unit (M-ECU) is configured to actuate at least one of the associated dedicated solenoid valve (MV2k) and the associated outlet valve (AV1-AV4) in a selected braking mode, such that brake fluid is simultaneously discharged from the wheel brake via one of the associated dedicated solenoid valve (MV2k) and the associated outlet valve (AV1-AV4).

[0189] In one exemplary embodiment, the driving power system further includes at least one second pressure supply unit (BM2), preferably including a piston-cylinder unit or a rotary pump, the at least one second pressure supply unit being configured to supply brake fluid to a first brake circuit (BK1) and a second brake circuit (BK2) at least one inlet of the first pressure supply unit, wherein preferably, at least one isolation valve is provided for isolating the first brake circuit and / or the second brake circuit.

[0190] In one exemplary embodiment, the first pressure supply unit (BM1) is directly connected to exactly two of the wheel brakes (RB1-RB4), wherein exactly two of the wheel brakes (RB1-RB4) brake the wheels on the first axle, and / or provides an additional pressure supply unit (BM3) that is directly connected to at least two of the wheel brakes (RB1-RB4) on the second axle.

[0191] In one exemplary embodiment, the dedicated solenoid valve (MV2k) is configured to open when power is off, and is arranged such that the valve seat of the dedicated solenoid valve is directly connected to at least one of the wheel brakes (RB1-RB4).

[0192] In one exemplary embodiment, the main control unit (M-ECU) is configured to detect a fault in at least one wheel brake circuit including one of the wheel brakes (RB1-RB4) and close the dedicated solenoid valve (MV2k) assigned to the one of the wheel brakes (RB1-RB4) to disconnect the wheel brake circuit.

[0193] In one exemplary embodiment, the first pressure supply unit (BM1) includes a rotary pump connected to the wheel brakes (RB1-RB4) and configured to increase and decrease the pressure in the wheel brakes (RB1-RB4).

[0194] In one exemplary embodiment, the dedicated solenoid valve (MV2k), particularly the dedicated solenoid valve (MV2k) assigned to the second pressure supply unit (BM2), is configured such that the seat of the dedicated solenoid valve is directly connected to the inlet of the first pressure supply unit (BM1).

[0195] In one exemplary embodiment, during a pressure reduction, at least one of the dedicated solenoid valves (MV2k) is actuated, in particular by PWM control or current control, to provide a variable valve opening cross-section.

[0196] In one exemplary embodiment, the actuators of the first auxiliary control unit (S-ECU1) and / or the second auxiliary control unit (S-ECU2a, S-ECU2b) and / or the first and / or the second pressure supply units (BM1, BM2) and / or the sensors of the first and / or the second pressure supply units (BM1, BM2) are particularly connected via a communication interface (Int BM1 Int BM2 It is communicatively connected to the main control unit (M-ECU) to execute the steering command and / or the braking command.

[0197] In one exemplary embodiment, the main control unit (M-ECU) is configured to: Pressure control for the wheel brake is achieved by activating at least one dedicated solenoid valve in the first pressure supply unit and / or at least one dedicated solenoid valve in the second pressure supply unit; and / or When the dedicated solenoid valve or inlet valve of the first pressure supply unit is closed, a wheel circuit fault is detected by measuring the pressure; and / or The faulty braking circuit is isolated by closing at least one of the isolation valves (TV1, TV2); and / or ABS is achieved axially by controlling at least one of the isolation valves (TV1, TV2) and alternately increasing and decreasing the pressure via the second pressure supply unit; and / or ABS for the wheels is achieved by controlling at least one of the dedicated solenoid valves (MV2k), and in particular by controlling the outlet valve of the first pressure supply unit, and alternately increasing and decreasing the pressure 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 axis-by-axis by controlling the dedicated solenoid valve (MV2K) allocated to the second pressure supply unit; and / or Automatic emergency braking is achieved by actuating the traction motors (TM1, TM2) and at least the first pressure supply unit (BM1) in parallel.

[0198] In one exemplary embodiment, the electromagnetic drive device (EM1) employs a redundant design and is equipped with at least one first solenoid valve driver and one second solenoid valve driver, wherein the auxiliary control unit (S-ECU1) for controlling the at least one dedicated solenoid valve (MV2k) is communicatively connected to the first solenoid valve driver, and the main control unit (M-ECU) for controlling the at least one dedicated solenoid valve (MV2k) is communicatively connected to the second solenoid valve driver.

[0199] In one exemplary embodiment, the main control unit (M-ECU) is configured to, at least temporarily, regulate the braking pressure in at least a portion of the wheel brakes (RB1-RB4) using multiplexing and / or PPC methods.

[0200] Embodiments of the present invention also provide a method for adjusting the braking pressure within at least one wheel brake in a braking system, preferably via an inlet valve for allowing brake fluid to enter the wheel brake and an outlet valve for discharging brake fluid from the wheel brake (RB1-RB4), the method comprising: Determine that at least one of the wheel brakes (RB1-RB4) needs to be reduced, including the pressure in the target wheel brake; Select the buck mode from the first buck mode and the second buck mode; When the first pressure reduction mode is selected, at least one of the outlet valves associated with the target wheel brake is opened to perform pressure reduction; When the second pressure reduction mode is selected, the outlet valve associated with the target wheel brake is kept closed and at least one of the inlet valves associated with the target wheel brake is opened, and a pressure differential is formed externally, preferably in the second pressure supply unit, to reduce the pressure in the target wheel brake via the inlet valve.

[0201] In one exemplary embodiment, the main control unit (M-ECU) of the driving power system is configured to implement the aforementioned method.

[0202] Figure Labels M-ECU main control unit, central computer R1-R4 wheels vR1-vR4 wheel speed sensor RB1-RB4 wheel brakes BK1 and BK2 braking circuits Connection points A1 and A2 BM1 First Braking Module DV1 pressure generator M motor P pump set Spk accumulator room S-ECU1 is the control unit for the first braking module. RP rotary pump KP piston pump MKP Multi-Piston Pump BM2 Second Braking Module DV2 pressure generator S-ECU2a Second Braking Module Control Unit S-ECU2b Second Braking Module Control Unit TV1, TV2 isolation valves BM3 Additional Braking Module RV, RV1, RV2 check valves AV1, AV2, AV3, AV4 outlet valves EV1, EV2, EV3, EV4 inlet valves Valves of HSV1, HSV2, USV1, and USV2ESP devices MV2k is a dedicated solenoid valve for pressure increase and decrease. TM1 is the first electric traction motor used to drive axles or wheels. TM2 is a second electric traction motor used to drive axles or wheels. TM3 is a third electric traction motor used to drive axles or wheels. VB reservoir VA front axle HA rear axle FRF utilizes the restoring force generated by the spring. FPM Magnetic FEM1, FEM2 Magnetic Force PM permanent magnet EM1 and EM2 magnetic circuits RF reset spring SP1, SP1a, SP1b, SP2 excitation coils 6 Armature 6a Additional armature 7 Valve Actuator 7a Valve tappet 10-pole plate 13. Return spring VS valve seat AR Armature Chamber MS1 and MS2 electromagnetic coils S air gap S1 - S4 power semiconductors

Claims

1. A driving power system, said driving power system being applied to a vehicle having wheels (R1-R4), comprising: The main control unit (M-ECU) is used to detect and / or generate steering and braking commands; At least two hydraulically actuated wheel brakes (RB1-RB4), wherein each of the wheel brakes is associated with one of the wheels (R1-R4); At least one electric traction motor has a traction motor control unit, wherein the traction motor (TM1, TM2) is used to drive at least one of the wheels (R1-R4), and the main control unit is communicatively connected to the traction motor control unit to control the traction motor (TM1, TM2) to execute the steering command and the braking command; At least one first electro-hydraulic pressure supply unit (BM1) includes: At least one electric pump unit; At least two connection lines for connecting the wheel brakes (RB1-RB4); Electrically actuated wheel brake pressure regulating valves or brake pressure regulating valves (AV1-AV4, EV1-EV4); and First auxiliary control unit (S-ECU1). At least one of the hydraulically actuated wheel brakes (RB1-RB4) is associated with an outlet valve, which is a brake pressure regulating valve and an outlet valve (AV1-AV4). The brake pressure regulating valve is in the form of an inlet valve (EV1-EV4). The main control unit (M-ECU) is configured to evaluate information and use that information for effective and predictive pressure regulation or pressure control, wherein the information includes camera information about road conditions or information about the surrounding environment, such as distances to pedestrians and / or vehicles.

2. The driving power system according to claim 1, wherein, The inlet valve is used to both increase and decrease pressure, and braking torque adjustment for individual wheels can be achieved through direct control of the main control unit.

3. The driving power system according to claim 1 or 2, wherein, The inlet valves (EV1-EV4) are configured as dedicated solenoid valves (MV2k), wherein the driving power system, in particular the main control unit (M-ECU), is configured to release pressure in the at least one hydraulically actuated wheel brake via the associated outlet valve or via the dedicated solenoid valve (MV2k).

4. The driving power system according to any one of the preceding claims, particularly according to claim 3, wherein, The dedicated solenoid valve (MV2k) has an anti-passive shut-off function through a throttling design, or the dedicated solenoid valve has an electromagnetic drive device with a first excitation coil (SP1, SP1a). The valve actuator (7) or valve tappet (7a) can be adjusted between the valve open position and the valve closed position via the first excitation coil. The dedicated solenoid valve (MV2k) has an additional force device including a permanent magnet (PM).

5. The driving power system according to any one of the preceding claims, wherein, It also includes at least one second pressure supply unit (BM2), preferably including a piston-cylinder unit or a rotary pump, the at least one second pressure supply unit being configured to supply brake fluid to a first brake circuit (BK1) and a second brake circuit (BK2) at at least one inlet of the first pressure supply unit, wherein preferably, at least one isolation valve is provided for isolating the first brake circuit and / or the second brake circuit.

6. The driving power system according to claim 3 or 4, wherein, The dedicated solenoid valve (MV2k) is configured to open when power is off and is arranged such that the valve seat of the dedicated solenoid valve is directly connected to at least one of the wheel brakes (RB1-RB4).

7. The driving power system according to any one of the preceding claims, wherein, The main control unit (M-ECU) is configured to detect a fault in at least one wheel brake circuit, including one of the wheel brakes (RB1-RB4), and to close the inlet valve (EV1-EV4), in particular a dedicated solenoid valve (MV2k), assigned to the wheel brake (RB1-RB4) to disconnect the wheel brake circuit.

8. The driving power system according to any one of the preceding claims, wherein, The first pressure supply unit (BM1) includes a rotary pump connected to the wheel brakes (RB1-RB4) and configured to increase and decrease the pressure in the wheel brakes (RB1-RB4).

9. The driving power system according to any one of claims 1-7, wherein, The first pressure supply unit (BM1) includes a multi-piston pump.

10. The driving power system according to any one of the preceding claims, particularly according to claim 8 or 9, wherein the first pressure supply unit is configured to perform a pressure reduction operation, particularly by releasing pressure directly to the reservoir (VB) via outlet valves (AV1, AV2).

11. The driving power system according to any one of the preceding claims, particularly according to claim 10, wherein, The first pressure supply unit includes an interface (Int) connected to the main control unit (M-ECU). BM1 This allows the central control unit to issue set values ​​for adjusting the braking torque of individual wheels through the main control unit (M-ECU).

12. The driving power system according to any one of the preceding claims, wherein, The actuators of the first auxiliary control unit (S-ECU1) and / or the second auxiliary control unit (S-ECU2a, S-ECU2b) and / or the first and / or the second pressure supply units (BM1, BM2) and / or the sensors of the first and / or the second pressure supply units (BM1, BM2) can be specifically transmitted via a communication interface (Int). BM1 Int BM2 It is communicatively connected to the main control unit (M-ECU) to execute the steering command and / or the braking command.

13. The driving power system according to any one of the preceding claims, particularly according to claim 12, wherein, The main control unit (M-ECU) is configured to: Pressure control of the wheel brakes is achieved by activating at least one of the second pressure supply units; and / or Wheel circuit faults are detected by measuring pressure after closing the inlet valve; and / or The faulty braking circuit is isolated by closing at least one of the isolation valves (TV1, TV2); and / or Automatic emergency braking is achieved by actuating the traction motors (TM1, TM2) and at least the first pressure supply unit (BM1) in parallel.

14. A method for adjusting the braking pressure in at least one wheel brake in a braking system via an inlet valve and an outlet valve, wherein, The inlet valve is used to allow brake fluid to enter the wheel brakes, and the outlet valve is used to discharge brake fluid from the wheel brakes (RB1-RB4). The method includes: Determine that the pressure of at least one of the wheel brakes (RB1-RB4), i.e. the target wheel brake, needs to be reduced; Select the buck mode from the first buck mode and the second buck mode; When the first pressure reduction mode is selected, at least one of the outlet valves associated with the target wheel brake is opened to release pressure directly to the reservoir (VB) to achieve pressure reduction. When the second pressure reduction mode is selected, the outlet valve associated with the target wheel brake is kept closed and at least one of the inlet valves associated with the target wheel brake is opened, and a pressure differential is formed in the external second pressure supply unit to reduce the pressure in the target wheel brake via the inlet valve.

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