Braking system with flexible architecture and method for operating such a braking system

Abstract

The invention relates generally to a braking system with flexible architecture and a method for operating such a braking system for a motor vehicle. The braking system can comprise a brake pedal with a pedal sensor for detecting the driver's request, and electrically controlled wheel brake modules. The pedal sensor can be connected to an electronic control unit, which generates control information for the power electronics from the braking information of the pedal sensor. The power electronics are used to control the wheel brakes.

Description

[0001] Braking system with flexible architecture and method for operating such a braking system

[0002] Description

[0003] The invention generally relates to a braking system with a flexible architecture and a method for operating such a braking system for a motor vehicle. The braking system may comprise a brake pedal with a pedal sensor for detecting the driver's input and electrically controllable wheel brake modules.

[0004] "Brake-by-wire" braking systems are becoming increasingly widespread in automotive technology. Such braking systems often include a brake pedal configured as an e-pedal. The brake pedal detects the driver's braking command using a sensor and generates a driver braking command signal. In these braking systems, the driver is decoupled from direct control of the brakes. The detected braking command can lead to the determination of a target braking torque, from which the target braking pressure for the brakes can then be determined.

[0005] The wheel brakes can be designed as electromechanical (dry) brakes. The driver's braking command signal can be transmitted to a central control unit, which takes over the electrical control of the wheel brakes.

[0006] The disadvantage of such a braking system design is that in the event of a central control unit failing, a fallback level must be switched on in order to maintain essential functions of the braking system.

[0007] Against this background, the applicant's document DE 10 2022 203 770.7 proposes an operating system with improved safety. The braking system described here provides two axle controllers, with two wheel brake modules assigned to a first axle controller and two additional wheel brake modules assigned to a second axle controller. Each of the two axle controllers is connected to the brake pedal on the signal input side. Furthermore, each of the two axle controllers comprises two control units, each of which controls a wheel brake.

[0008] In this concept, the brake pedal is connected to each axle controller. The functionality required to convert the brake signals from the brake pedal into control signals for the control units must therefore be provided in the axle controller and, in particular, in the redundant control units, which can lead to a cost disadvantage.

[0009] In addition, the integration of brake-by-wire braking systems into existing vehicle configurations, which were conventionally equipped with hydraulic components, requires a considerable amount of adaptation to the braking system or the vehicle configuration, whereby customer-specific requirements often also have to be taken into account.

[0010] What is desirable is a braking system which, on the one hand, meets the applicable safety requirements, including those for driverless driving, and which, on the other hand, can be adapted cost-effectively and flexibly to different vehicle configurations, customer requirements or safety requirements.

[0011] The inventors have taken on this task.

[0012] This object is achieved surprisingly simply by a braking system, in particular for a motor vehicle, and a method for operating such a braking system according to one of the independent claims. Preferred embodiments and further developments of the invention can be found in the respective subclaims.

[0013] The invention accordingly comprises, in a first aspect, a braking system, in particular for a motor vehicle, comprising a brake pedal with at least one pedal sensor for detecting the driver's command; four electrically controllable wheel brake modules, each comprising an electromechanical wheel brake, at least one control electronics unit, and at least one power electronics unit designed to control at least one electromechanical wheel brake, wherein the pedal sensor is connected to at least one control electronics unit via at least one braking command signal line, and wherein the at least one control electronics unit is configured to generate control information for the power electronics from the braking information of the pedal sensor and to transmit it to the power electronics.

[0014] The braking system is designed as a by-wire braking system within the meaning of the invention and can have a dry brake pedal, also referred to as an e-pedal. It is also possible to use a "wet" brake pedal, which is electrically connected accordingly. The brake pedal can advantageously be designed to generate a corresponding signal, also referred to as braking information, from the measured driver braking command, which can be transmitted to the control electronics via at least one braking command signal line.

[0015] For reasons of redundancy, it may be advantageous to provide at least two separate, advantageously redundant, i.e., two functionally identical brake request signal lines, which serve to transmit signals between the brake pedal and the control electronics. For this purpose, the brake request signal line can be designed as a bidirectional brake request signal line. It is advantageous to provide at least one brake request signal line between the brake pedal and each control electronics.

[0016] The brake pedal can comprise at least two pedal sensors, which are advantageously based on two different measuring principles. For example, a force sensor that detects the force with which the driver presses the pedal and a displacement sensor that measures the distance the driver presses the pedal can be used. The error patterns for these different pedal sensors vary, so that, for example, a jammed pedal can be detected by force being applied to the pedal without it moving.

[0017] Based on the sensor signals, information or signals can be generated for the electromechanical braking system that correspond to the driver's braking request. These signals can be transmitted to the control electronics via the braking request signal line during operation.

[0018] In a first aspect, the invention is based on the idea of ​​grouping or bundling various functionalities, including the control and regulation, operation, or power supply of the electromechanical wheel brakes, hereinafter also referred to for simplicity as elements of the braking system, according to specific criteria or requirements. It should be noted at this point that, within the scope of this application, no distinction is made between the terms "control" and "regulate." The meaning of the corresponding terms arises from the respective context.

[0019] This makes it particularly convenient to implement specific requirements, for example, regarding redundancy and the connection of the braking system to the motor vehicle or to the vehicle's powertrain. Redundancy in this sense refers to the multiple, preferably duplicate, presence of the corresponding functions or associated elements. Especially in safety-relevant systems, which includes a braking system, a parallel design of functions or elements ensures that if one function or element fails, another takes over these functions, thus enabling continued operation, at least to a certain extent.

[0020] The braking system according to the invention is thus extremely flexible in terms of its architecture and can be manufactured cost-effectively and adapted to customer specifications. Defined communication interfaces, for example, to a vehicle's data bus, can also be provided particularly advantageously.

[0021] One criterion here could be the reduction of unsprung masses, according to which only the absolutely necessary components should be mounted on the wheel. In addition to the brake actuators, these include wheel sensors, such as a motor position sensor and / or a wheel speed sensor. The invention makes it possible to provide brake system architectures tailored to this.

[0022] Another criterion may be the provision of the necessary redundancy of the system-relevant elements, since there is a risk of errors in technical systems, which, under unfavorable circumstances, could lead to a reduction in braking performance and thus to dangerous situations. Accordingly, it must be ensured that the driver's braking request can be determined even in the event of a fault and can be implemented with the available brake actuators. The invention allows the architecture of the braking system to be optimized such that only certain elements of the braking system need to be designed redundantly, thus reducing the additional costs resulting from redundant design.

[0023] Another criterion may be the number and length of the required signal or data bus lines that must be provided for the braking system and that are necessary to connect the various elements of the braking system for signal or data exchange. For cost reasons, the number and length of the required signal or data bus lines should be kept as low as possible.

[0024] Yet another criterion may be the number of points or locations on or in the motor vehicle where a power supply is to be provided. Here, too, it may be advantageous to keep the number of these points low, while simultaneously minimizing the number and length of the power lines. Against this background, the invention proposes, in a preferred embodiment, structurally and / or spatially separating the connection of the pedal sensors and the evaluation of the signals or the generation of the control information from the power electronics, which serve to directly control and supply power to the wheel brake.

[0025] The control electronics are therefore designed to generate control information for the power electronics from the signals from the brake pedal sensors and transmit it to the power electronics via a suitable data bus. This can be done, in particular, with computer support based on stored algorithms or using suitable software.

[0026] The power electronics can be designed to control and / or operate the electromechanical wheel brakes based on or from the control information.

[0027] This advantageously allows the control electronics to be arranged flexibly within the motor vehicle, regardless of the design of the wheel brake modules. In other words, the power electronics can, for example, be assigned directly to a wheel. The wheel brake module can therefore comprise an electromechanical wheel brake and the associated power electronics.

[0028] Likewise, architectures can also be implemented in which the power electronics, for example, of two wheels on an axle, are combined in pairs to form an axle controller. In this case, the wheel brake module essentially comprises the wheel brake with a corresponding power supply for the brake actuator, and the power supply and / or control is provided via the power electronics located in the axle controller.

[0029] Furthermore, architectures can also be implemented in which the power electronics are combined diagonally in a so-called diagonal controller. A diagonal controller can therefore comprise two power electronics units for supplying power and / or controlling a front wheel and an oppositely arranged rear wheel.

[0030] The respective power electronics can be flexibly adapted to specific customer requirements and, for example, designed with high or low redundancy. High redundancy can mean that if one element fails, all of that element's functions can be ensured by another element, whereas lower redundancy can only ensure some of the lost functions if an element fails. In connection with braking systems such as the present one, this also includes, in particular, the degree of degradation of the braking system.

[0031] The control electronics can be arranged in the vehicle independently of the power electronics or the axle or diagonal controller. This makes it possible, for example, to locate the control electronics at defined points in the vehicle that are particularly well-suited for connection to at least one of the vehicle's data buses via appropriate interfaces.

[0032] For redundancy reasons, it is advantageous to provide two separate supply voltages for two control electronics units. Furthermore, one or two separate power supplies can be provided for each power electronics unit or for each axis or diagonal controller.

[0033] The control electronics can each communicate with each other via at least one data bus of the motor vehicle, but direct data bus lines can also be provided. Additional data bus lines are advantageously provided between the control electronics and the power electronics or the axle or diagonal controllers. It will be apparent to those skilled in the art that this results in a multitude of possible braking system architectures, which can be adapted to the specific requirements in a specific case relatively easily and cost-effectively. Modularization also results in cost advantages.

[0034] Preferably, all wheel brakes of the motor vehicle are designed as electromechanical or electrically controllable wheel brakes.

[0035] The electromechanical wheel brakes can be designed as electromechanical disc brakes, in which an application force can be generated by means of an electric motor, a primary gear, and a rotation / translation gear. The application force refers to the force with which the brake pads are pressed against the brake disc. During operation, this then generates a corresponding braking torque at the wheel in question. Depending on the design and control concept, the control can be selected such that either a predefined, defined application force or a predefined, defined braking torque is set according to the requested deceleration.

[0036] The electromechanical wheel brakes can also be designed as electromechanical drum brakes, in which the engine-Z-gearbox unit actuates a spreading module that presses the brake pads against the brake drum with a spreading force determined by the desired deceleration, thus generating a corresponding braking torque. Depending on the design and control concept, the control can be configured to set a defined spreading force or braking torque according to the desired deceleration.

[0037] In the braking system according to the invention, for example, the two brakes assigned to the front axle can be designed as electromechanical disc brakes, and the two brakes assigned to the rear axle can be designed as electromechanical drum brakes. However, all brakes can also be designed as electromechanical disc brakes or as electromechanical drum brakes.

[0038] If the mechanical connection between the brake pedal and the wheel brakes is decoupled, an external power supply is required that generates braking torque or clamping force independently of the driver's force. In a favorable embodiment of the invention, a redundant power supply is provided.

[0039] The power electronics can provide the appropriate power or energy supply for the electromechanical wheel brake, for which purpose appropriate power lines can be provided. Signal lines can also be provided, for example, to connect the wheel sensors to the power electronics.

[0040] In a further aspect, the invention also relates to a method for operating a braking system as described above, in particular in connection with or for a motor vehicle.

[0041] Further details of the invention emerge from the description of the illustrated embodiments and the appended claims.

[0042] The drawings show:

[0043] Fig. 1 shows a schematic plan view of an example of an architecture of a braking system according to the invention for a motor vehicle,

[0044] Fig. 2 shows another example of an architecture of a braking system according to the invention,

[0045] Fig. 3 shows a schematic circuit diagram of a power electronics,

[0046] Fig. 4 shows yet another example of an architecture of a braking system according to the invention, Fig. 5 shows an example of redundant power electronics,

[0047] Fig. 6 an example of a partially redundant power electronics,

[0048] Fig. 7 an example of a non-redundant power electronics,

[0049] Fig. 8 another example of partially redundant power electronics,

[0050] Fig. 9 another example of power electronics,

[0051] Fig. 10 shows an architecture of another braking system according to the invention,

[0052] Fig. 11 an architecture of yet another inventive

[0053] braking system,

[0054] Fig. 12 an architecture of yet another braking system according to the invention,

[0055] Fig. 13 an architecture of yet another braking system according to the invention, and

[0056] Fig. 14a, 14b and 14c Architectures for the power supply of four wheel brakes of a motor vehicle.

[0057] In the following detailed description of preferred embodiments, for the sake of clarity, like reference numerals designate substantially similar parts in or on these embodiments. However, to better illustrate the invention, the preferred embodiments illustrated in the figures are not always drawn to scale.

[0058] Fig. 1 shows in a schematic plan view an example of a braking system 2 according to the invention, in particular for a motor vehicle, comprising a brake pedal 72 with at least one pedal sensor for detecting the driver's request; four electrically controllable wheel brake modules 6, 10, 40, 44, each comprising an electromechanical wheel brake 20, 24, 54, 58, at least one control electronics unit 90, 91, and at least one power electronics unit 32, 36, 64, 68, which is designed to control at least one electromechanical wheel brake 20, 24, 54, 58, wherein the pedal sensor is connected to at least one control electronics unit 90, 91 via at least one braking request signal line 76, 78, and wherein the at least one control electronics unit 90, 91 is set up to generate control information for the power electronics unit 32, 36, 64, 68 from the braking information of the pedal sensor and to transmit it to the power electronics unit 32, 36, 64, 68.

[0059] The braking system 2 shown in Fig. 1 has two wheel brake modules 6, 10, which are assigned to a rear wheel axle 14 of a motor vehicle and each have a first and second rear wheel brake 20, 24 (the motors are shown in each case).

[0060] The braking system 2 further comprises two wheel brake modules 40, 44, which are assigned to a front wheel axle 50 and each have a first and second front wheel brake 54, 58.

[0061] In the illustrated embodiment, the electromechanical wheel brakes 20, 24, 54, 58 are designed as electromechanical disc brakes. However, the electromechanical wheel brakes can also be designed as electromechanical drum brakes, for example, the two wheel brakes 20, 24 assigned to the rear axle 14.

[0062] In the exemplary embodiment, the braking system 2 is designed as a dry by-wire braking system and has a dry brake pedal 72 (E-pedal in the present case). In the exemplary embodiment shown, the brake pedal comprises two sensors based on two different measuring principles. Firstly, there is a force sensor that detects the force with which the driver presses the pedal, and secondly, there is a displacement sensor that measures the distance the driver presses the pedal. In this way, redundancy can be created with regard to the detection of the driver's braking request, since the error patterns are different for these different sensors, so that, for example, a jammed pedal can be detected by force being exerted on the pedal without it moving.Preferably, the brake pedal 72 sends the signals from these two sensors as braking information to a first control electronics unit 90 ("Veh prim", "Brake 1") and to a second control electronics unit 91 ("Veh sec", "Brake 2"), which then uses computer support to calculate the control information for the power electronics. Other brake pedal designs, such as a "wet" brake pedal, are also possible.

[0063] Other necessary components, for example wheel sensors 70, can be mounted on the wheel, such as an engine position sensor and / or a wheel speed sensor.

[0064] According to a first aspect of the invention, certain functionalities relating to the control and regulation or the operation or the power supply of the electromechanical wheel brakes are separated or grouped according to certain criteria.

[0065] To ensure easy integration into existing vehicle concepts and high flexibility, the invention separates the functionality of generating a braking request signal from the brake pedal sensor signals on the one hand and controlling the wheel brake modules on the other. This allows for particularly simple implementation of certain redundancy requirements.

[0066] According to the invention, control electronics 90, 91 are therefore provided, which are connected to the brake pedal 72. Based on the sensor signals, braking information or signals for the electromechanical braking system 2 can be generated, which correspond to the driver's braking request. For this purpose, the brake pedal 72 is connected to the control electronics 90, 91 via a respective braking request signal line 76, 78. The two braking request signal lines 76, 78 are bidirectional in this case. This control electronics 90, 91 is designed to generate control information for the power electronics 32, 36, 64, 68 from the signals of the at least one pedal sensor of the brake pedal 72 and to transmit it to the power electronics 32, 36, 64, 68. This can be done, in particular, with computer support based on stored algorithms or by means of appropriate software.The control electronics 90, 91 can comprise a corresponding microprocessor with a memory.

[0067] In the present case, the control electronics 90, 91 are also connected to the motor vehicle via a data bus. In the exemplary embodiment in Fig. 1, two data bus lines 106, 107 are schematically shown for this purpose, in the example CAN bus systems. This also makes it possible to meet redundancy requirements, for example in the event of a data bus line 106, 107 failing. The control electronics 90, 91 can also be connected to a vehicle-mounted computer via the data bus. In this way, it is also possible to access algorithms or software of the vehicle-mounted computer to generate the control information. Furthermore, it is also possible for the control information to be generated on the vehicle side and transmitted to the braking system 2 via the control electronics 90, 91.

[0068] As can be seen in Fig. 1, the control electronics 90, 91 are implemented in duplicate for redundancy reasons, i.e. the elements assigned to the control electronics, such as electronic components such as the microprocessor, are housed in two spatially separate and spaced-apart modules or housings. The functionality of the two control electronics 90, 91 is preferably identical, i.e. a first control electronics 90, 91 has the same range of functions as the second control electronics 90, 91, so that complete redundancy is ensured. For communication with each other, the two control electronics 90, 91 are connected to one another via two data bus lines 96, 97, so that redundant data transmission is also possible in this regard.According to a preferred embodiment of the invention, a first control electronics unit 90 can be operated in regular mode, and the second control electronics unit 91 can initially be operated in standby mode. In the event of a failure of the first control electronics unit 90, the required functionality can then be completely taken over by the second control electronics unit 91.

[0069] Furthermore, as shown in Fig. 1, both control electronics 90, 91 are each equipped with a separate power supply, the first control electronics 90 with a first supply voltage 110 and the second control electronics 91 with a second supply voltage 111.

[0070] A braking system 2 with two such control electronics 90, 91 makes it possible in a highly advantageous manner to provide different architectures and control concepts for the individual wheel brake modules.

[0071] For example, as shown in Fig. 1, the power electronics 64, 68 on the front axle 50 can each be assigned to the corresponding electromechanical wheel brake 54, 58. In this case, the wheel brake modules 40, 44 are each connected to the first control electronics 90 via a redundant data bus line 92, 93 and to the second control electronics 91 via a further, likewise redundant data bus line 94, 95. Furthermore, a power supply is provided for each power electronics 64, 68 via a corresponding supply voltage 110, 111 on the wheel brake modules.

[0072] If the power electronics 64, 68 are directly assigned to the respective electromechanical wheel brakes 54, 58, the control takes place via the data bus lines 92, 93, 94, 95 between the control electronics 90, 91 and the power electronics 64, 68.

[0073] Due to the functional separation, an axle controller 28 or axle control unit ("ACU") can advantageously be provided on the rear axle 14, as shown in Fig. 1. This axle controller 28 includes the power electronics 32, 36 for controlling the rear wheel brakes 20, 24. The axle controller 28 is thus part of the sprung masses, which has a positive effect on the handling. In the exemplary embodiment, a first power electronics unit 32 for controlling the first rear wheel brake 20 (e.g., for a left vehicle wheel) and a second power electronics unit 36 ​​for controlling the second rear wheel brake 24 (e.g., for a right vehicle wheel) are provided in the axle controller 28.

[0074] In the embodiment shown in Fig. 1, the axle control unit 28 is internally divided into two independent wheel control units or power electronics 32, 26, which, for redundancy reasons, have a separate power supply with two supply voltages 110, 111 (KI30 per circuit board). The two power electronics 32, 36 are therefore separate from each other but arranged in a common housing of the axle controller 28. The two power electronics 32, 36 can also be arranged on a common circuit board, as shown in the following examples, which simplifies manufacturing.

[0075] The electric motor of the electromechanical wheel brake 20 is supplied with power directly via the power line 112 by the power electronics 32, and the electric motor of the electromechanical wheel brake 24 is supplied with power via the power line 113 by the power electronics 36. Furthermore, signal lines 114, 115 to the wheel brakes 20, 24 are provided. The electric motor can, in a manner known to those skilled in the art, apply a clamping force in the case of an electromechanical disc brake or a spreading force in the case of an electromechanical drum brake, whereby a transmission with a corresponding converter can be provided.

[0076] Furthermore, a preferably redundant data transmission is provided between the power electronics 32 and 36 of the axle controller 28. The two power electronics 32, 36 are designed to be fully redundant, so that if one power electronics 32 fails, the other power electronics 36 can assume the functionality of controlling both wheel brakes 20, 24.

[0077] In the exemplary embodiment, the two wheel brake modules 6, 10 each have, for example, a pawl or other locking options or these are integrated into the wheel brake module 6, 10, whereby the functionality of an electronic parking brake is realized.

[0078] In other preferred embodiments of the braking system 2 according to the invention, all wheel brake modules 6, 10, 40, 44 can also have a locking pawl or other locking options, which is advantageous especially with regard to the requirements of driverless driving.

[0079] In a further development of the invention, a braking system 2 is proposed in which control electronics 90, 91 are arranged adjacent to or together with an axle controller, preferably in a common module or even in a common housing. This makes it possible to bundle certain functionalities. In the exemplary embodiment shown in Fig. 1, the second control electronics 91 is arranged spatially adjacent to the axle controller 28. In a preferred embodiment of the invention, the control electronics 91 and the axle controller 28 are housed in a common module or a common housing, as indicated in Fig. 1.

[0080] Such an architecture as shown in Fig. 1 is particularly easy to integrate into the vehicle and also cost-effective to implement, since, for example, a power supply only needs to be established for this module and not for the control electronics 90, 91 and an axle controller. The power supply can, in turn, be designed redundantly with two separate supply voltages 110, 111, as shown in Fig. 1.

[0081] Fig. 2 shows a schematic plan view of an architecture for another braking system 2 according to the invention. In this exemplary embodiment, as in the architectures of braking systems 2 according to the invention presented below, the braking system 2 is designed as a by-wire braking system and has a dry brake pedal 72. The brake pedal also includes two sensors based on two different measuring principles.

[0082] In the embodiment of Fig. 2, the electromechanical wheel brakes 54, 58 of the front axle 51 are also designed as electromechanical disc brakes, whereas the electromechanical wheel brakes 20, 24 of the rear axle 14 are designed as electromechanical drum brakes. The power electronics 32, 36, 64, 68 are each directly assigned to the corresponding electromechanical wheel brake 40, 44, 54, 58, thereby increasing the extent of the unsprung masses. In this embodiment of the invention, data bus lines 92, 93, 96, 97 are provided between the first control electronics 90 and the power electronics 32, 36, 64, 68, as well as further data bus lines 94, 95, 98, 99 are provided between the second control electronics 91 and the power electronics 32, 36, 64, 68. For the sake of clarity, the vehicle's data bus lines are not always shown in this and the following illustrations.

[0083] The control electronics 90, 91 are in turn designed to be redundant, so that if the first control electronics 90 fails, the second control electronics 91 can take over operation of the electromechanical wheel brakes 40, 44, 54, 58. Although shown separately in Fig. 2, in this embodiment the two control electronics 90, 91 can also be housed in a common module or in a common housing, which can facilitate connection to the motor vehicle's data bus and the power supply. However, even in such arrangements, two separate supply voltages 110, 111 are provided for each control electronics 90, 91 for redundancy reasons.

[0084] The power electronics 32, 36, 64, 68, (“ECU”), in this case also referred to as the so-called “Wheel Control Unit” or “WCU”, can be designed accordingly simply and is supplied with a first or a second supply voltage 110, 111 per axle, in the example in a diagonal manner, ie the supply voltages front left and rear right as well as front right and rear left belong to different power supplies.

[0085] In this example, the power electronics 32, 36, 64, 68 are identical for each wheel and have a comparatively simple design, as shown in Fig. 3, but must be provided for each wheel. In the case of separate power electronics directly assigned to a wheel, a microprocessor 101 ("MCU") must also be provided, which ensures communication with the data buses and controls the assigned power electronics of the respective wheel.

[0086] If one of the two control electronics 90, 91 fails, no reduction in braking performance is to be expected. Instead, a warning is generated, for example, by illuminating a warning lamp.

[0087] Fig. 3 shows a schematic circuit diagram of a power electronics unit 32, 36, 64, 68 (WCU) for an architecture according to the exemplary embodiment of Fig. 2. The power electronics unit 32, 36, 64, 68 has a B6 bridge 100. Three lines 120, 124, 128 lead from the B6 bridge 100 to the motor of the respective wheel brake 20, 24, 54, 58 and thus represent the power lines 112, 113, respectively. Furthermore, the power electronics unit 32, 36, 64, 68 in the example shown includes a microprocessor 101.

[0088] Fig. 4 shows in a schematic plan view another example of an architecture of a braking system 2 according to the invention, which is similar to that shown in Fig. 2 with regard to the electromechanical wheel brakes 20, 24, 54, 58.

[0089] In this exemplary embodiment, the power electronics 32, 36, 64, 68 are combined in pairs per axle, i.e., a second axle controller 60 is provided, which includes the power electronics 64, 68. This allows the undamped mass at the wheels to be further reduced, since all power electronics can be arranged, for example, in a favorable center of gravity position in a central area of ​​the motor vehicle.

[0090] In this embodiment, the power electronics 32, 36, 64, 68 in the two axle controllers 28, 60 are connected to the two control electronics 90, 91 via the corresponding data bus lines 92, 93, 94, 95, 96, 97, 98, 99. Power lines 112, 113 lead from the axle controllers 28, 60 to the electromechanical wheel brakes 20, 24, 54, 58. A separate, vehicle-side power supply to the wheel brake modules is thus unnecessary. The combination of functionalities, in particular with regard to the power electronics 32, 36, 64, 68 in one or two axis controllers 28, 60, makes it possible to design the power electronics 32, 36, 64, 68 in a customer-specific manner in a particularly simple manner, in particular in conjunction with two control electronics 90, 91 as shown in Figures 1 or 2.

[0091] Customer-specific requirements regarding security or requirements regarding the redundancy of certain elements can be implemented particularly easily.

[0092] The following Figures 5 to 9 show, purely by way of example, various circuit diagrams for power electronics 32, 36, 64, 68, each in a simplified representation, which can be used for or with a braking system 2 according to the invention. In the examples, a circuit board is provided for each axle controller 28, 60, which summarizes the required functionality. A single circuit board can often be manufactured cost-effectively and easily assembled. However, it is also possible to provide a separate circuit board for each power electronics unit and to house these circuit boards in a common housing.

[0093] The invention makes it possible to implement different configurations of the respective power electronics 32, 36, 64, 68 in a particularly simple manner, since the brake pedal 72 and / or the interface to the data bus of the motor vehicle are not connected to the axle controllers 28, 60 and in this respect a high degree of flexibility is achieved with regard to the redundancy of individual elements or components of the power electronics 32, 36, 64, 68.

[0094] It should be noted at this point that the following embodiments with regard to the redundancy of the power electronics 32, 36, 64, 68 also apply analogously to the diagonal controllers 80, 81 described in more detail below.

[0095] It will be understood by those skilled in the art that, in the case of two axle controllers 28, 60, the respective power electronics for controlling the wheel brakes 20, 24, 54, 58 can be designed identically or differently. In other words, both axle controllers 28, 60 can comprise identically designed power electronics 32, 36, 64, 68, but also different ones, for example, with different redundancy.

[0096] Fig. 5 shows an example of fully redundant power electronics 32, 36 for an axle controller, with one power electronics 32, 36 each being provided to control a wheel brake 20, 24 of an axle. It will be understood by those skilled in the art that when two power electronics units of a diagonal controller are combined, the power electronics units are assigned to the wheel brakes diagonally, as explained in more detail below.

[0097] During normal operation, the two power electronics units 32, 36 operate independently of each other and control the respective wheel brakes 20, 24 individually. Both power electronics units 32, 36 are each supplied with their own power supply 110, 111. Additionally, signal lines, such as those from the control electronics, lead to the two power electronics units 32, 36, which are only indicated for clarity.

[0098] In the event of a power supply failure, for example, the power electronics 32, 36 not affected by the failure takes over the control of both wheel brakes 20, 24. For this purpose, the two power electronics 32, 36 in the axle controller 28, 60 are connected to one another in such a way that in the event of a first power electronics 32 failure, the second power electronics 36 takes over the control of the wheel brake 20, 24 which is assigned to the failed power electronics 32.

[0099] For this purpose, a data bus line between the two power electronics 32, 36 and a circuit 102 are provided in the axis controller 28, 60.

[0100] The power electronics 32, 36 comprise a control connection with a B6 bridge 100 for connecting to the other power electronics 32, 36. In this way, in particular, the three phases of an electric motor of a wheel brake 20, 24 can be connected to the other power electronics 32, 36. To ensure electronic redundancy, in the event of a fault in a B6 bridge / GDU on the other side, the B6 bridge / GDU on one side is used to synchronously control both motors of the electromechanical wheel brakes 20, 24. In this case, the motors can only be operated synchronously; however, this is sufficient for brake force amplification. The prerequisite here is that both motors have the same alignment angle, which is made possible by synchronized travel at the beginning of the motor control.

[0101] A cross switch is arranged in the respective control connection 102. Blown fuses are preferably arranged in the respective connection of a B6 bridge to a wheel brake. The B6 bridge on the side of the functioning control unit is used to blow the fuses, which are preferably designed as ETFs ("electric thermal fuses"), in the control connection of the non-functioning control unit. Therefore, a cross switch is required on each side behind the ETFs on the other side.

[0102] Complete redundancy here includes the failure of a power supply or supply voltage 110, 111 in one of the two power electronics 32, 36, the failure of the signal of a motor position sensor 72 or the failure of a microprocessor 101. In these cases, the redundant design of the power electronics 32, 36 ensures that the power electronics 32, 36 not affected in each case takes over the functions of the power electronics affected by the fault.

[0103] Fig. 6 shows an example of partially redundant power electronics 32, 36 of an axle controller 28, 60 for controlling a wheel brake 20, 24, 54, 58. In this embodiment, the microprocessor 101 and the B6 bridge 100 are still redundant, but for cost reasons, the circuit 102 is no longer provided to the extent shown in Fig. 5. Switching of the power supply in the event of a supply voltage 110, 111 failure is therefore no longer possible, so that this design of the power electronics of the axle controller 28, 60 does not provide complete redundancy, but only partial redundancy.

[0104] It is also possible to configure an axle controller 28, 60 with two identical power electronics units 32, 26 without redundancy. In this case, the two combined power electronics units 32, 26 can also be considered a "WCU" for each wheel. Such an arrangement is shown purely as an example in Fig. 7. Although no redundancy is provided here, cost advantages can arise because only a single circuit board is used for the power electronics of both wheel brakes of an axle.

[0105] Fig. 8 shows a further example of partially redundant power electronics 32 of an axle controller 28, 60 for controlling one wheel brake each 20, 24, 54, 58. In this embodiment of the axle controller 28, 60, a second, redundant microprocessor 101 is omitted; i.e., only one microprocessor 101 supplies both B6 bridges 100. This results in further cost advantages by eliminating the need for one microprocessor 101; however, the scope of the redundant functions is also correspondingly limited. In other words, if one microprocessor 101 fails, control is no longer possible. The power electronics are also connected to two supply voltages 110, 111, which can be operated alternately.

[0106] Fig. 9 shows a further example of power electronics 32 of an axle controller 28, 60 for controlling a wheel brake 20, 24, 54, 58. This embodiment of the axle controller 28, 60 is based on the embodiment from Fig. 8. However, the power electronics 32 is only connected to a supply voltage 110, ie if this supply voltage fails, the wheel brakes can no longer be controlled.

[0107] Fig. 10 shows a schematic plan view of an example of the architecture of another braking system 2 according to the invention, which largely corresponds to the braking system 2 shown in Fig. 1. In this exemplary embodiment, the braking system 2 is also designed as a by-wire braking system and has a dry brake pedal 72. The brake pedal also includes two sensors based on two different measuring principles. The rear wheel brakes 20, 24 are designed as electromechanical drum brakes.

[0108] Fig. 11 shows a schematic plan view of an example of a further braking system 2 according to the invention. The brake pedal and the data bus lines to the vehicle are not shown for the sake of clarity.

[0109] However, the functionality regarding the control of the respective wheel brakes in this exemplary embodiment is combined differently than in the other examples. In particular, the exemplary embodiment in Fig. 11 shows that the power electronics 32, 36, 64, 68 for controlling diagonally opposite wheel brakes 20, 24, 54, 58 are combined into so-called diagonal controllers 80, 81 ("DCU").

[0110] Accordingly, the diagonal controller 80 includes the power electronics 36 for controlling the rear right wheel brake 24 and the power electronics 64 for controlling the front left wheel brake 54. Furthermore, the diagonal controller 81 includes the power electronics 32 for controlling the rear left wheel brake 20 and the power electronics 68 for controlling the front right wheel brake 58. The respective power electronics 32, 36, 64, 68 are again combined in pairs, albeit diagonally, so that the undamped masses are also reduced in this embodiment.

[0111] Accordingly, power lines 112, 113 are to be provided from the diagonal controllers 80, 81 to the diagonally arranged wheel brakes.

[0112] Such an arrangement offers the advantage that if a diagonal controller 80, 81 fails completely, at least one front wheel and one rear wheel can still be braked, whereas in an arrangement with two axle controllers, if one axle controller 90, 91 fails, one axle can no longer be braked.

[0113] The power electronics 32, 36, 64, 68 of the diagonal controllers 80, 81 can be constructed analogously to the embodiments shown in Figures 5 to 9 with regard to redundancy. Accordingly, a diagonal controller 80, 81 can comprise power electronics 32, 36, 64, 68, which are configured analogously to the examples in Figures 5 to 9.

[0114] According to a further development of the invention, at least one diagonal controller 80, 81 can also be assigned to a front wheel or integrated into it, for example.

[0115] Fig. 12 shows a schematic plan view of an example of the architecture of another braking system 2 according to the invention with two axle controllers 28, 60. In this embodiment, a control electronics unit 91 is assigned to the front axle's axle controller 60. Compared to the embodiment shown in Fig. 4, which also has two axle controllers 28, 60 and two separately arranged control electronics units 90, 91, the power supply can be simplified in this embodiment because the second control electronics unit 91 is structurally combined with the axle controller 60.

[0116] Fig. 13 shows a schematic plan view of an example of another braking system 2 according to the invention with two axle controllers 28, 60. In this embodiment, both control electronics 90, 91 are each assigned to an axle controller 28, 60. The control electronics 90, 91 are also connected to the data bus lines 106, 107 of the motor vehicle. The required power supply can be further simplified compared to the embodiment shown in Fig. 12 and is limited to a redundant supply voltage 106, 107 for the structurally combined elements of control electronics 90, 91 and axle controllers 28, 60.

[0117] In a further aspect of the invention, the functional separation or grouping within the meaning of the invention also relates to the power supply of the wheel brakes. Figures 14a, 14b, and 14c show possible architectures for the power supply of four wheel brakes of a motor vehicle using schematic diagrams.

[0118] In the embodiment shown in Fig. 14a, a diagonal power supply is provided to the wheel brakes 20, 24, 54, 58. A diagonal power supply here means a power supply to the wheel brakes in which diagonally opposite wheel brakes each have the same power supply. As can be seen in Fig. 14a, the front right and rear left wheel brakes 58, 20 are connected to a supply voltage 111, and the front left and rear right wheel brakes 54, 24 are connected to a supply voltage 110. In the event of a complete failure of a supply voltage 110, 111, this arrangement halves the brake force boost. This embodiment enables a simple design of the interface to the wheel brake module 6, 10, 40, 44, which can essentially comprise a connection for the power supply and for signal or data lines. In the embodiment shown in Fig.The embodiment shown in Figure 14b also provides a diagonal individual power supply to the wheel brakes 20, 24, 54, 58, but with mutual switching in the event of a power failure. This circuit 102 is also shown schematically in the figure. This advantageously results in all four wheel brakes still being able to operate in the event of a power supply failure 110, 111. Targeted axle control is also conceivable and possible here, i.e., switching the power supply to individual wheel brakes so that, for example, only the wheel brakes on the front axle are supplied with power.

[0119] In the embodiment shown in Fig. 14c, a dual power supply is provided for the wheel brakes 54, 58 on the front wheel. A dual power supply here means a power supply for the front wheel brakes 54, 58, in which each wheel brake has two power supplies. As can be seen in Fig. 14c, the front right and front left wheel brakes 54, 58 are connected to a first supply voltage 110 and a first supply voltage 111, respectively. This results in the failure of only one rear wheel brake in the event of a supply voltage failure 110, 111.

[0120] It is obvious to the person skilled in the art that the architectures shown here can be combined with one another in various ways with regard to the control of the wheel brakes, the design of the power controls and the power supply, and that the architectures shown merely represent possible embodiments.

[0121] List of reference symbols:

[0122] 2 braking system

[0123] 6 Wheel brake module

[0124] 10 Wheel brake module

[0125] 14 Rear axle

[0126] 20 Rear brake

[0127] 24 Rear brake

[0128] 28 axis controllers

[0129] 32 Power electronics

[0130] 36 Power electronics

[0131] 40 Wheel brake module

[0132] 44 Wheel brake module

[0133] 50 front wheel axle

[0134] 54 Front brake

[0135] 58 front brake

[0136] 60 axis controllers

[0137] 64 Power electronics

[0138] 68 Power electronics

[0139] 70 wheel sensor

[0140] 72 Brake pedal

[0141] 76 Brake request signal line

[0142] 78 Brake request signal line

[0143] 80 diagonal controllers

[0144] 81 diagonal controllers

[0145] 82 Signal line

[0146] 86 Signal line control electronics

[0147] Control electronics

[0148] Data bus line

[0149] Data bus line

[0150] Data bus line

[0151] Data bus line

[0152] Data bus line

[0153] Data bus line

[0154] Data bus line

[0155] Data bus line

[0156] B6-B back

[0157] microprocessor

[0158] circuit

[0159] B6-B back

[0160] data bus

[0161] data bus

[0162] Supply voltage

[0163] Supply voltage

[0164] power line

[0165] power line

[0166] Signal line

[0167] Signal line

Claims

Braking system (2), in particular for a motor vehicle, comprising a brake pedal (72) with at least one pedal sensor for detecting the driver's request; four electrically controllable wheel brake modules (6, 10, 40, 44), each comprising an electromechanical wheel brake (20, 24, 54, 58), at least one control electronics unit (90, 91), and at least one power electronics unit (32, 36, 64, 68) which is designed to control at least one electromechanical wheel brake (20, 24, 54, 58), wherein the pedal sensor is connected to at least one control electronics unit (90, 91) via at least one braking request signal line (76, 78), and wherein the at least one control electronics unit (90, 91) is designed to generate control information for the power electronics (32, 36, 64, 68) from the braking information of the pedal sensor and to transmit it to the power electronics (32, 36, 64, 68).Braking system (2) according to the preceding claim, characterized in that the brake pedal (72) comprises at least two pedal sensors based on two different measuring principles, in particular a force sensor and a displacement sensor, and wherein the signals from both pedal sensors can be transmitted to the control electronics (90, 91) during operation. Braking system (2) according to the preceding claim, characterized in that the pedal sensor is connected to a respective control electronics (90, 91) via at least two brake request signal lines (76, 78). Braking system (2) according to one of the preceding claims, characterized in that the electromechanical wheel brakes (20, 24, 54, 58) are designed as electromechanical disc brakes or as electromechanical drum brakes. Braking system (2) according to one of the preceding claims, characterized in that the electromechanical wheel brake (54, 58) of the front wheel (50) is designed as an electromechanical disc brake, and the electromechanical wheel brake (20, 24) of the rear wheel (14) is designed as an electromechanical drum brake. Braking system (2) according to one of the preceding claims, characterized in that the control electronics (90, 91) are designed redundantly, each control electronics (90, 91) having the same functionality with regard to generating the control information for the power electronics (32, 36, 64, 68).Braking system (2) according to one of the preceding claims, characterized in that the control electronics (90, 91) are housed in two spatially separate and / or spaced-apart modules or housings. Braking system (2) according to one of the preceding claims, characterized in that at least one data bus line (96, 97), preferably two data bus lines (96, 97), for data transmission is arranged between the separately arranged control electronics (90, 91). Braking system (2) according to one of the preceding claims, characterized in that the control electronics (90, 91) are arranged spatially separate from the power electronics (32, 36, 64, 68). Braking system (2) according to one of the preceding claims, characterized in that data bus lines (92, 93, 94, 95) for data transmission are arranged between the control electronics (90, 91) and the power electronics (32, 36, 64, 68). Braking system (2) according to one of the preceding claims, characterized in that the control electronics (90, 91) comprise at least one microprocessor (101), preferably one microprocessor (101) per control electronics (90, 91). Braking system (2) according to one of the preceding claims, characterized in that the control electronics (90, 91) are connected to the data bus of the motor vehicle. Braking system (2) according to one of the preceding claims, characterized in that each control electronics (90, 91) has its own separate supply voltage (110, 111).Braking system (2) according to one of the preceding claims, characterized in that both control electronics (90, 91) are accommodated in a common module or in a common housing. Braking system (2) according to one of the preceding claims, characterized in that on the front axle (50), the power electronics (64, 68) are directly assigned to the respective electromechanical wheel brake (54, 58) and / or that on the rear axle (14), the power electronics (32, 36) are directly assigned to the respective electromechanical wheel brake (20, 24). Braking system (2) according to one of the preceding claims, characterized in that an axle controller (60) is provided on the front axle (50), which axle controller controls the power electronics (64, 68). the front wheel brakes (54, 58), and / or that an axle controller (28) is provided on the rear axle (14), which comprises the power electronics (32, 36) for controlling the rear wheel brakes (20, 24).

17. Braking system (2) according to one of the preceding claims, characterized in that at least one diagonal controller (80, 81) is provided, which comprises the power electronics (32, 36, 64, 68) for controlling diagonally oppositely arranged wheel brakes (20, 24, 54, 58).

18. Braking system (2) according to one of the preceding claims, characterized in that at least one control electronics unit (90, 91) is accommodated together with a power electronics unit (32, 36, 64, 68) or an axle controller (28, 60) or with a diagonal controller (80, 81) in a common module or in a common housing.

19. Braking system (2) according to one of the preceding claims, characterized in that the power electronics (32, 36, 64, 68) of an axle controller (28, 60) or a diagonal controller (80, 81) each have a separate supply voltage (110, 111).

20. Braking system (2) according to one of the preceding claims, characterized in that the power electronics (32, 36, 64, 68) of an axle controller (28, 60) or of a diagonal controller (80, 81) are designed to be completely redundant, wherein the two power electronics (32, 36, 64, 68) of an axle controller (28, 60) or of a diagonal controller (80, 81) have the same functionality.

21. Braking system (2) according to one of the preceding claims, characterized in that the power electronics (32, 36, 64, 68) of an axle controller (28, 60) or a diagonal controller (80, 81) have only one common supply voltage (110, 111). Braking system (2) according to one of the preceding claims, characterized in that the power electronics (32, 36, 64, 68) of an axle controller (28, 60) or a diagonal controller (80, 81) have only one common microprocessor (101). Braking system (2), in particular for a motor vehicle, preferably according to one of the preceding claims, comprising a brake pedal (72) with at least one pedal sensor for detecting the driver's input; four electrically controllable wheel brake modules (6, 10, 40, 44), each comprising an electromechanical wheel brake (20, 24, 54, 58), at least one power electronics unit (32, 36, 64, 68) which is designed to control the electromechanical wheel brakes (20, 24, 54, 58), wherein the power electronics unit (32, 36, 64, 68) is combined in an axle controller (28, 60) or a diagonal controller (80, 81) for controlling at least two electromechanical wheel brakes (20, 24, 54, 58).Braking system (2) according to the preceding claim, further comprising control electronics, wherein the pedal sensor is connected to control electronics (90, 91) via at least one braking request signal line (76, 78), and wherein the at least one control electronics (90, 91) is configured to generate control information for the power electronics (32, 36, 64, 68) from the braking information of the pedal sensor and to transmit it to the power electronics (32, 36, 64, 68). Braking system (2), in particular for a motor vehicle, preferably according to one of the preceding claims, comprising a brake pedal (72) with at least one pedal sensor for detecting the driver's request. four electrically controllable wheel brake modules (6, 10, 40, 44), each comprising an electromechanical wheel brake (20, 24, 54, 58), at least one power electronics unit (32, 36, 64, 68) configured to control at least one electromechanical wheel brake (20, 24, 54, 58), wherein a diagonal power supply is provided at the wheel brakes (20, 24, 54, 58), in which diagonally opposite wheel brakes are connected to the same supply voltage (110, 111). Braking system (2) according to the preceding claim, characterized in that the power supply comprises a switching unit (102) for mutual switching in the event of a supply voltage failure (110, 111).Braking system (2), in particular for a motor vehicle, preferably according to one of the preceding claims, comprising a brake pedal (72) with at least one pedal sensor for detecting the driver's input; four electrically controllable wheel brake modules (6, 10, 40, 44), each comprising an electromechanical wheel brake (20, 24, 54, 58), at least one power electronics unit (32, 36, 64, 68) designed to control at least one electromechanical wheel brake (20, 24, 54, 58), wherein a power supply with dual supply of the wheel brakes (54, 58) is provided on the front wheel, wherein each wheel brake on the front wheel is connected to a first supply voltage (110) and to a second supply voltage (111), and wherein the wheel brakes (20, 24) of the rear wheel preferably have only a single power supply. Braking system (2) according to one of the preceding claims, characterized in that the electrically controllable wheel brake modules (6,. 10, 40, 44) also include the associated power electronics (32, 36, 64, 68). Braking system (2) according to one of the preceding claims, characterized in that the brake pedal (72) is designed as a dry brake pedal (72).

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